Fixed MTP to work with TWRP

arch/arm64/kernel/Makefile

@@ -0,0 +1,48 @@
+#
+# Makefile for the linux kernel.
+#
+
+CPPFLAGS_vmlinux.lds	:= -DTEXT_OFFSET=$(TEXT_OFFSET)
+AFLAGS_head.o		:= -DTEXT_OFFSET=$(TEXT_OFFSET)
+CFLAGS_efi-stub.o 	:= -DTEXT_OFFSET=$(TEXT_OFFSET)
+CFLAGS_armv8_deprecated.o := -I$(src)
+
+CFLAGS_REMOVE_ftrace.o = -pg
+CFLAGS_REMOVE_insn.o = -pg
+CFLAGS_REMOVE_return_address.o = -pg
+
+# Object file lists.
+arm64-obj-y		:= cputable.o debug-monitors.o entry.o irq.o fpsimd.o	\
+			   entry-fpsimd.o process.o ptrace.o setup.o signal.o	\
+			   sys.o stacktrace.o time.o traps.o io.o vdso.o	\
+			   hyp-stub.o psci.o cpu_ops.o insn.o return_address.o	\
+			   cpuinfo.o cpu_errata.o alternative.o
+
+arm64-obj-$(CONFIG_COMPAT)		+= sys32.o kuser32.o signal32.o 	\
+					   sys_compat.o				\
+					   ../../arm/kernel/opcodes.o
+arm64-obj-$(CONFIG_FUNCTION_TRACER)	+= ftrace.o entry-ftrace.o
+arm64-obj-$(CONFIG_MODULES)		+= arm64ksyms.o module.o
+arm64-obj-$(CONFIG_SMP)			+= smp.o smp_spin_table.o topology.o
+arm64-obj-$(CONFIG_PERF_EVENTS)		+= perf_regs.o
+arm64-obj-$(CONFIG_HW_PERF_EVENTS)	+= perf_event.o
+arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o
+arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND)	+= sleep.o suspend.o
+arm64-obj-$(CONFIG_CPU_IDLE)		+= cpuidle.o
+arm64-obj-$(CONFIG_JUMP_LABEL)		+= jump_label.o
+arm64-obj-$(CONFIG_KGDB)		+= kgdb.o
+arm64-obj-$(CONFIG_ARCH_EXYNOS)		+= exynos-smc.o
+arm64-obj-$(CONFIG_EFI)			+= efi.o efi-stub.o efi-entry.o
+arm64-obj-$(CONFIG_TIMA_RKP)		+= rkp_entry.o
+arm64-obj-$(CONFIG_PCI)			+= pci.o
+arm64-obj-$(CONFIG_ARMV8_DEPRECATED)	+= armv8_deprecated.o
+arm64-obj-$(CONFIG_KEXEC)		+= machine_kexec.o
+
+obj-y					+= $(arm64-obj-y) vdso/
+obj-m					+= $(arm64-obj-m)
+head-y					:= head.o
+extra-y					:= $(head-y) vmlinux.lds
+
+# vDSO - this must be built first to generate the symbol offsets
+$(call objectify,$(arm64-obj-y)): $(obj)/vdso/vdso-offsets.h
+$(obj)/vdso/vdso-offsets.h: $(obj)/vdso

arch/arm64/kernel/alternative.c

@@ -0,0 +1,64 @@
+/*
+ * alternative runtime patching
+ * inspired by the x86 version
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define pr_fmt(fmt) "alternatives: " fmt
+
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <asm/cacheflush.h>
+#include <asm/alternative.h>
+#include <asm/cpufeature.h>
+#include <linux/stop_machine.h>
+
+extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
+
+static int __apply_alternatives(void *dummy)
+{
+	struct alt_instr *alt;
+	u8 *origptr, *replptr;
+
+	for (alt = __alt_instructions; alt < __alt_instructions_end; alt++) {
+		if (!cpus_have_cap(alt->cpufeature))
+			continue;
+
+		BUG_ON(alt->alt_len > alt->orig_len);
+
+		pr_info_once("patching kernel code\n");
+
+		origptr = (u8 *)&alt->orig_offset + alt->orig_offset;
+		replptr = (u8 *)&alt->alt_offset + alt->alt_offset;
+		memcpy(origptr, replptr, alt->alt_len);
+		flush_icache_range((uintptr_t)origptr,
+				   (uintptr_t)(origptr + alt->alt_len));
+	}
+
+	return 0;
+}
+
+void apply_alternatives(void)
+{
+	/* better not try code patching on a live SMP system */
+	stop_machine(__apply_alternatives, NULL, NULL);
+}
+
+void free_alternatives_memory(void)
+{
+	free_reserved_area(__alt_instructions, __alt_instructions_end,
+			   0, "alternatives");
+}

arch/arm64/kernel/arm64ksyms.c

@@ -0,0 +1,67 @@
+/*
+ * Based on arch/arm/kernel/armksyms.c
+ *
+ * Copyright (C) 2000 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/cryptohash.h>
+#include <linux/delay.h>
+#include <linux/in6.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+
+#include <asm/checksum.h>
+
+EXPORT_SYMBOL(copy_page);
+EXPORT_SYMBOL(clear_page);
+
+	/* user mem (segment) */
+EXPORT_SYMBOL(__copy_from_user);
+EXPORT_SYMBOL(__copy_to_user);
+EXPORT_SYMBOL(__clear_user);
+EXPORT_SYMBOL(__copy_in_user);
+
+	/* physical memory */
+EXPORT_SYMBOL(memstart_addr);
+
+	/* string / mem functions */
+EXPORT_SYMBOL(strchr);
+EXPORT_SYMBOL(strrchr);
+EXPORT_SYMBOL(strcmp);
+EXPORT_SYMBOL(strncmp);
+EXPORT_SYMBOL(strlen);
+EXPORT_SYMBOL(strnlen);
+EXPORT_SYMBOL(memset);
+EXPORT_SYMBOL(memcpy);
+EXPORT_SYMBOL(memmove);
+EXPORT_SYMBOL(memchr);
+EXPORT_SYMBOL(memcmp);
+
+	/* atomic bitops */
+EXPORT_SYMBOL(set_bit);
+EXPORT_SYMBOL(test_and_set_bit);
+EXPORT_SYMBOL(clear_bit);
+EXPORT_SYMBOL(test_and_clear_bit);
+EXPORT_SYMBOL(change_bit);
+EXPORT_SYMBOL(test_and_change_bit);
+
+#ifdef CONFIG_FUNCTION_TRACER
+EXPORT_SYMBOL(_mcount);
+#endif

arch/arm64/kernel/armv8_deprecated.c

@@ -0,0 +1,662 @@
+/*
+ *  Copyright (C) 2014 ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/cpu.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/perf_event.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/sysctl.h>
+
+#include <asm/insn.h>
+#include <asm/opcodes.h>
+#include <asm/system_misc.h>
+#include <asm/traps.h>
+#include <asm/uaccess.h>
+#include <asm/cpufeature.h>
+
+#define CREATE_TRACE_POINTS
+#include "trace-events-emulation.h"
+
+/*
+ * The runtime support for deprecated instruction support can be in one of
+ * following three states -
+ *
+ * 0 = undef
+ * 1 = emulate (software emulation)
+ * 2 = hw (supported in hardware)
+ */
+enum insn_emulation_mode {
+	INSN_UNDEF,
+	INSN_EMULATE,
+	INSN_HW,
+};
+
+enum legacy_insn_status {
+	INSN_DEPRECATED,
+	INSN_OBSOLETE,
+};
+
+struct insn_emulation_ops {
+	const char		*name;
+	enum legacy_insn_status	status;
+	struct undef_hook	*hooks;
+	int			(*set_hw_mode)(bool enable);
+};
+
+struct insn_emulation {
+	struct list_head node;
+	struct insn_emulation_ops *ops;
+	int current_mode;
+	int min;
+	int max;
+};
+
+static LIST_HEAD(insn_emulation);
+static int nr_insn_emulated;
+static DEFINE_RAW_SPINLOCK(insn_emulation_lock);
+
+static void register_emulation_hooks(struct insn_emulation_ops *ops)
+{
+	struct undef_hook *hook;
+
+	BUG_ON(!ops->hooks);
+
+	for (hook = ops->hooks; hook->instr_mask; hook++)
+		register_undef_hook(hook);
+
+	pr_notice("Registered %s emulation handler\n", ops->name);
+}
+
+static void remove_emulation_hooks(struct insn_emulation_ops *ops)
+{
+	struct undef_hook *hook;
+
+	BUG_ON(!ops->hooks);
+
+	for (hook = ops->hooks; hook->instr_mask; hook++)
+		unregister_undef_hook(hook);
+
+	pr_notice("Removed %s emulation handler\n", ops->name);
+}
+
+static void enable_insn_hw_mode(void *data)
+{
+	struct insn_emulation *insn = (struct insn_emulation *)data;
+	if (insn->ops->set_hw_mode)
+		insn->ops->set_hw_mode(true);
+}
+
+static void disable_insn_hw_mode(void *data)
+{
+	struct insn_emulation *insn = (struct insn_emulation *)data;
+	if (insn->ops->set_hw_mode)
+		insn->ops->set_hw_mode(false);
+}
+
+/* Run set_hw_mode(mode) on all active CPUs */
+static int run_all_cpu_set_hw_mode(struct insn_emulation *insn, bool enable)
+{
+	if (!insn->ops->set_hw_mode)
+		return -EINVAL;
+	if (enable)
+		on_each_cpu(enable_insn_hw_mode, (void *)insn, true);
+	else
+		on_each_cpu(disable_insn_hw_mode, (void *)insn, true);
+	return 0;
+}
+
+/*
+ * Run set_hw_mode for all insns on a starting CPU.
+ * Returns:
+ *  0 		- If all the hooks ran successfully.
+ * -EINVAL	- At least one hook is not supported by the CPU.
+ */
+static int run_all_insn_set_hw_mode(unsigned long cpu)
+{
+	int rc = 0;
+	unsigned long flags;
+	struct insn_emulation *insn;
+
+	raw_spin_lock_irqsave(&insn_emulation_lock, flags);
+	list_for_each_entry(insn, &insn_emulation, node) {
+		bool enable = (insn->current_mode == INSN_HW);
+		if (insn->ops->set_hw_mode && insn->ops->set_hw_mode(enable)) {
+			pr_warn("CPU[%ld] cannot support the emulation of %s",
+				cpu, insn->ops->name);
+			rc = -EINVAL;
+		}
+	}
+	raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
+	return rc;
+}
+
+static int update_insn_emulation_mode(struct insn_emulation *insn,
+				       enum insn_emulation_mode prev)
+{
+	int ret = 0;
+
+	switch (prev) {
+	case INSN_UNDEF: /* Nothing to be done */
+		break;
+	case INSN_EMULATE:
+		remove_emulation_hooks(insn->ops);
+		break;
+	case INSN_HW:
+		if (!run_all_cpu_set_hw_mode(insn, false))
+			pr_notice("Disabled %s support\n", insn->ops->name);
+		break;
+	}
+
+	switch (insn->current_mode) {
+	case INSN_UNDEF:
+		break;
+	case INSN_EMULATE:
+		register_emulation_hooks(insn->ops);
+		break;
+	case INSN_HW:
+		ret = run_all_cpu_set_hw_mode(insn, true);
+		if (!ret)
+			pr_notice("Enabled %s support\n", insn->ops->name);
+		break;
+	}
+
+	return ret;
+}
+
+static void register_insn_emulation(struct insn_emulation_ops *ops)
+{
+	unsigned long flags;
+	struct insn_emulation *insn;
+
+	insn = kzalloc(sizeof(*insn), GFP_KERNEL);
+	insn->ops = ops;
+	insn->min = INSN_UNDEF;
+
+	switch (ops->status) {
+	case INSN_DEPRECATED:
+		insn->current_mode = INSN_EMULATE;
+		/* Disable the HW mode if it was turned on at early boot time */
+		run_all_cpu_set_hw_mode(insn, false);
+		insn->max = INSN_HW;
+		break;
+	case INSN_OBSOLETE:
+		insn->current_mode = INSN_UNDEF;
+		insn->max = INSN_EMULATE;
+		break;
+	}
+
+	raw_spin_lock_irqsave(&insn_emulation_lock, flags);
+	list_add(&insn->node, &insn_emulation);
+	nr_insn_emulated++;
+	raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
+
+	/* Register any handlers if required */
+	update_insn_emulation_mode(insn, INSN_UNDEF);
+}
+
+static int emulation_proc_handler(struct ctl_table *table, int write,
+				  void __user *buffer, size_t *lenp,
+				  loff_t *ppos)
+{
+	int ret = 0;
+	struct insn_emulation *insn = (struct insn_emulation *) table->data;
+	enum insn_emulation_mode prev_mode = insn->current_mode;
+
+	table->data = &insn->current_mode;
+	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+
+	if (ret || !write || prev_mode == insn->current_mode)
+		goto ret;
+
+	ret = update_insn_emulation_mode(insn, prev_mode);
+	if (ret) {
+		/* Mode change failed, revert to previous mode. */
+		insn->current_mode = prev_mode;
+		update_insn_emulation_mode(insn, INSN_UNDEF);
+	}
+ret:
+	table->data = insn;
+	return ret;
+}
+
+static struct ctl_table ctl_abi[] = {
+	{
+		.procname = "abi",
+		.mode = 0555,
+	},
+	{ }
+};
+
+static void register_insn_emulation_sysctl(struct ctl_table *table)
+{
+	unsigned long flags;
+	int i = 0;
+	struct insn_emulation *insn;
+	struct ctl_table *insns_sysctl, *sysctl;
+
+	insns_sysctl = kzalloc(sizeof(*sysctl) * (nr_insn_emulated + 1),
+			      GFP_KERNEL);
+
+	raw_spin_lock_irqsave(&insn_emulation_lock, flags);
+	list_for_each_entry(insn, &insn_emulation, node) {
+		sysctl = &insns_sysctl[i];
+
+		sysctl->mode = 0644;
+		sysctl->maxlen = sizeof(int);
+
+		sysctl->procname = insn->ops->name;
+		sysctl->data = insn;
+		sysctl->extra1 = &insn->min;
+		sysctl->extra2 = &insn->max;
+		sysctl->proc_handler = emulation_proc_handler;
+		i++;
+	}
+	raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
+
+	table->child = insns_sysctl;
+	register_sysctl_table(table);
+}
+
+/*
+ *  Implement emulation of the SWP/SWPB instructions using load-exclusive and
+ *  store-exclusive.
+ *
+ *  Syntax of SWP{B} instruction: SWP{B}<c> <Rt>, <Rt2>, [<Rn>]
+ *  Where: Rt  = destination
+ *	   Rt2 = source
+ *	   Rn  = address
+ */
+
+/*
+ * Error-checking SWP macros implemented using ldxr{b}/stxr{b}
+ */
+#define __user_swpX_asm(data, addr, res, temp, B)		\
+	__asm__ __volatile__(					\
+	"	mov		%w2, %w1\n"			\
+	"0:	ldxr"B"		%w1, [%3]\n"			\
+	"1:	stxr"B"		%w0, %w2, [%3]\n"		\
+	"	cbz		%w0, 2f\n"			\
+	"	mov		%w0, %w4\n"			\
+	"2:\n"							\
+	"	.pushsection	 .fixup,\"ax\"\n"		\
+	"	.align		2\n"				\
+	"3:	mov		%w0, %w5\n"			\
+	"	b		2b\n"				\
+	"	.popsection"					\
+	"	.pushsection	 __ex_table,\"a\"\n"		\
+	"	.align		3\n"				\
+	"	.quad		0b, 3b\n"			\
+	"	.quad		1b, 3b\n"			\
+	"	.popsection"					\
+	: "=&r" (res), "+r" (data), "=&r" (temp)		\
+	: "r" (addr), "i" (-EAGAIN), "i" (-EFAULT)		\
+	: "memory")
+
+#define __user_swp_asm(data, addr, res, temp) \
+	__user_swpX_asm(data, addr, res, temp, "")
+#define __user_swpb_asm(data, addr, res, temp) \
+	__user_swpX_asm(data, addr, res, temp, "b")
+
+/*
+ * Bit 22 of the instruction encoding distinguishes between
+ * the SWP and SWPB variants (bit set means SWPB).
+ */
+#define TYPE_SWPB (1 << 22)
+
+/*
+ * Set up process info to signal segmentation fault - called on access error.
+ */
+static void set_segfault(struct pt_regs *regs, unsigned long addr)
+{
+	siginfo_t info;
+
+	down_read(&current->mm->mmap_sem);
+	if (find_vma(current->mm, addr) == NULL)
+		info.si_code = SEGV_MAPERR;
+	else
+		info.si_code = SEGV_ACCERR;
+	up_read(&current->mm->mmap_sem);
+
+	info.si_signo = SIGSEGV;
+	info.si_errno = 0;
+	info.si_addr  = (void *) instruction_pointer(regs);
+
+	pr_debug("SWP{B} emulation: access caused memory abort!\n");
+	arm64_notify_die("Illegal memory access", regs, &info, 0);
+}
+
+static int emulate_swpX(unsigned int address, unsigned int *data,
+			unsigned int type)
+{
+	unsigned int res = 0;
+
+	if ((type != TYPE_SWPB) && (address & 0x3)) {
+		/* SWP to unaligned address not permitted */
+		pr_debug("SWP instruction on unaligned pointer!\n");
+		return -EFAULT;
+	}
+
+	while (1) {
+		unsigned long temp;
+
+		if (type == TYPE_SWPB)
+			__user_swpb_asm(*data, address, res, temp);
+		else
+			__user_swp_asm(*data, address, res, temp);
+
+		if (likely(res != -EAGAIN) || signal_pending(current))
+			break;
+
+		cond_resched();
+	}
+
+	return res;
+}
+
+/*
+ * swp_handler logs the id of calling process, dissects the instruction, sanity
+ * checks the memory location, calls emulate_swpX for the actual operation and
+ * deals with fixup/error handling before returning
+ */
+static int swp_handler(struct pt_regs *regs, u32 instr)
+{
+	u32 destreg, data, type, address = 0;
+	int rn, rt2, res = 0;
+
+	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->pc);
+
+	type = instr & TYPE_SWPB;
+
+	switch (arm_check_condition(instr, regs->pstate)) {
+	case ARM_OPCODE_CONDTEST_PASS:
+		break;
+	case ARM_OPCODE_CONDTEST_FAIL:
+		/* Condition failed - return to next instruction */
+		goto ret;
+	case ARM_OPCODE_CONDTEST_UNCOND:
+		/* If unconditional encoding - not a SWP, undef */
+		return -EFAULT;
+	default:
+		return -EINVAL;
+	}
+
+	rn = aarch32_insn_extract_reg_num(instr, A32_RN_OFFSET);
+	rt2 = aarch32_insn_extract_reg_num(instr, A32_RT2_OFFSET);
+
+	address = (u32)regs->user_regs.regs[rn];
+	data	= (u32)regs->user_regs.regs[rt2];
+	destreg = aarch32_insn_extract_reg_num(instr, A32_RT_OFFSET);
+
+	pr_debug("addr in r%d->0x%08x, dest is r%d, source in r%d->0x%08x)\n",
+		rn, address, destreg,
+		aarch32_insn_extract_reg_num(instr, A32_RT2_OFFSET), data);
+
+	/* Check access in reasonable access range for both SWP and SWPB */
+	if (!access_ok(VERIFY_WRITE, (address & ~3), 4)) {
+		pr_debug("SWP{B} emulation: access to 0x%08x not allowed!\n",
+			address);
+		goto fault;
+	}
+
+	res = emulate_swpX(address, &data, type);
+	if (res == -EFAULT)
+		goto fault;
+	else if (res == 0)
+		regs->user_regs.regs[destreg] = data;
+
+ret:
+	if (type == TYPE_SWPB)
+		trace_instruction_emulation("swpb", regs->pc);
+	else
+		trace_instruction_emulation("swp", regs->pc);
+
+	pr_warn_ratelimited("\"%s\" (%ld) uses obsolete SWP{B} instruction at 0x%llx\n",
+			current->comm, (unsigned long)current->pid, regs->pc);
+
+	regs->pc += 4;
+	return 0;
+
+fault:
+	set_segfault(regs, address);
+
+	return 0;
+}
+
+/*
+ * Only emulate SWP/SWPB executed in ARM state/User mode.
+ * The kernel must be SWP free and SWP{B} does not exist in Thumb.
+ */
+static struct undef_hook swp_hooks[] = {
+	{
+		.instr_mask	= 0x0fb00ff0,
+		.instr_val	= 0x01000090,
+		.pstate_mask	= COMPAT_PSR_MODE_MASK,
+		.pstate_val	= COMPAT_PSR_MODE_USR,
+		.fn		= swp_handler
+	},
+	{ }
+};
+
+static struct insn_emulation_ops swp_ops = {
+	.name = "swp",
+	.status = INSN_OBSOLETE,
+	.hooks = swp_hooks,
+	.set_hw_mode = NULL,
+};
+
+static int cp15barrier_handler(struct pt_regs *regs, u32 instr)
+{
+	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->pc);
+
+	switch (arm_check_condition(instr, regs->pstate)) {
+	case ARM_OPCODE_CONDTEST_PASS:
+		break;
+	case ARM_OPCODE_CONDTEST_FAIL:
+		/* Condition failed - return to next instruction */
+		goto ret;
+	case ARM_OPCODE_CONDTEST_UNCOND:
+		/* If unconditional encoding - not a barrier instruction */
+		return -EFAULT;
+	default:
+		return -EINVAL;
+	}
+
+	switch (aarch32_insn_mcr_extract_crm(instr)) {
+	case 10:
+		/*
+		 * dmb - mcr p15, 0, Rt, c7, c10, 5
+		 * dsb - mcr p15, 0, Rt, c7, c10, 4
+		 */
+		if (aarch32_insn_mcr_extract_opc2(instr) == 5) {
+			dmb(sy);
+			trace_instruction_emulation(
+				"mcr p15, 0, Rt, c7, c10, 5 ; dmb", regs->pc);
+		} else {
+			dsb(sy);
+			trace_instruction_emulation(
+				"mcr p15, 0, Rt, c7, c10, 4 ; dsb", regs->pc);
+		}
+		break;
+	case 5:
+		/*
+		 * isb - mcr p15, 0, Rt, c7, c5, 4
+		 *
+		 * Taking an exception or returning from one acts as an
+		 * instruction barrier. So no explicit barrier needed here.
+		 */
+		trace_instruction_emulation(
+			"mcr p15, 0, Rt, c7, c5, 4 ; isb", regs->pc);
+		break;
+	}
+
+ret:
+	pr_warn_ratelimited("\"%s\" (%ld) uses deprecated CP15 Barrier instruction at 0x%llx\n",
+			current->comm, (unsigned long)current->pid, regs->pc);
+
+	regs->pc += 4;
+	return 0;
+}
+
+static inline void config_sctlr_el1(u32 clear, u32 set)
+{
+	u32 val;
+
+	asm volatile("mrs %0, sctlr_el1" : "=r" (val));
+	val &= ~clear;
+	val |= set;
+	asm volatile("msr sctlr_el1, %0" : : "r" (val));
+}
+
+static int cp15_barrier_set_hw_mode(bool enable)
+{
+	if (enable)
+		config_sctlr_el1(0, SCTLR_EL1_CP15BEN);
+	else
+		config_sctlr_el1(SCTLR_EL1_CP15BEN, 0);
+	return 0;
+}
+
+static struct undef_hook cp15_barrier_hooks[] = {
+	{
+		.instr_mask	= 0x0fff0fdf,
+		.instr_val	= 0x0e070f9a,
+		.pstate_mask	= COMPAT_PSR_MODE_MASK,
+		.pstate_val	= COMPAT_PSR_MODE_USR,
+		.fn		= cp15barrier_handler,
+	},
+	{
+		.instr_mask	= 0x0fff0fff,
+		.instr_val	= 0x0e070f95,
+		.pstate_mask	= COMPAT_PSR_MODE_MASK,
+		.pstate_val	= COMPAT_PSR_MODE_USR,
+		.fn		= cp15barrier_handler,
+	},
+	{ }
+};
+
+static struct insn_emulation_ops cp15_barrier_ops = {
+	.name = "cp15_barrier",
+	.status = INSN_DEPRECATED,
+	.hooks = cp15_barrier_hooks,
+	.set_hw_mode = cp15_barrier_set_hw_mode,
+};
+
+static int setend_set_hw_mode(bool enable)
+{
+	if (!cpu_supports_mixed_endian_el0())
+		return -EINVAL;
+
+	if (enable)
+		config_sctlr_el1(SCTLR_EL1_SED, 0);
+	else
+		config_sctlr_el1(0, SCTLR_EL1_SED);
+	return 0;
+}
+
+static int compat_setend_handler(struct pt_regs *regs, u32 big_endian)
+{
+	char *insn;
+
+	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->pc);
+
+	if (big_endian) {
+		insn = "setend be";
+		regs->pstate |= COMPAT_PSR_E_BIT;
+	} else {
+		insn = "setend le";
+		regs->pstate &= ~COMPAT_PSR_E_BIT;
+	}
+
+	trace_instruction_emulation(insn, regs->pc);
+	pr_warn_ratelimited("\"%s\" (%ld) uses deprecated setend instruction at 0x%llx\n",
+			current->comm, (unsigned long)current->pid, regs->pc);
+
+	return 0;
+}
+
+static int a32_setend_handler(struct pt_regs *regs, u32 instr)
+{
+	int rc = compat_setend_handler(regs, (instr >> 9) & 1);
+	regs->pc += 4;
+	return rc;
+}
+
+static int t16_setend_handler(struct pt_regs *regs, u32 instr)
+{
+	int rc = compat_setend_handler(regs, (instr >> 3) & 1);
+	regs->pc += 2;
+	return rc;
+}
+
+static struct undef_hook setend_hooks[] = {
+	{
+		.instr_mask	= 0xfffffdff,
+		.instr_val	= 0xf1010000,
+		.pstate_mask	= COMPAT_PSR_MODE_MASK,
+		.pstate_val	= COMPAT_PSR_MODE_USR,
+		.fn		= a32_setend_handler,
+	},
+	{
+		/* Thumb mode */
+		.instr_mask	= 0x0000fff7,
+		.instr_val	= 0x0000b650,
+		.pstate_mask	= (COMPAT_PSR_T_BIT | COMPAT_PSR_MODE_MASK),
+		.pstate_val	= (COMPAT_PSR_T_BIT | COMPAT_PSR_MODE_USR),
+		.fn		= t16_setend_handler,
+	},
+	{}
+};
+
+static struct insn_emulation_ops setend_ops = {
+	.name = "setend",
+	.status = INSN_DEPRECATED,
+	.hooks = setend_hooks,
+	.set_hw_mode = setend_set_hw_mode,
+};
+
+static int insn_cpu_hotplug_notify(struct notifier_block *b,
+			      unsigned long action, void *hcpu)
+{
+	int rc = 0;
+	if ((action & ~CPU_TASKS_FROZEN) == CPU_STARTING)
+		rc = run_all_insn_set_hw_mode((unsigned long)hcpu);
+
+	return notifier_from_errno(rc);
+}
+
+static struct notifier_block insn_cpu_hotplug_notifier = {
+	.notifier_call = insn_cpu_hotplug_notify,
+};
+
+/*
+ * Invoked as late_initcall, since not needed before init spawned.
+ */
+static int __init armv8_deprecated_init(void)
+{
+	if (IS_ENABLED(CONFIG_SWP_EMULATION))
+		register_insn_emulation(&swp_ops);
+
+	if (IS_ENABLED(CONFIG_CP15_BARRIER_EMULATION))
+		register_insn_emulation(&cp15_barrier_ops);
+
+	if (IS_ENABLED(CONFIG_SETEND_EMULATION)) {
+		if(system_supports_mixed_endian_el0())
+			register_insn_emulation(&setend_ops);
+		else
+			pr_info("setend instruction emulation is not supported on the system");
+	}
+
+	register_cpu_notifier(&insn_cpu_hotplug_notifier);
+	register_insn_emulation_sysctl(ctl_abi);
+
+	return 0;
+}
+
+late_initcall(armv8_deprecated_init);

arch/arm64/kernel/asm-offsets.c

@@ -0,0 +1,165 @@
+/*
+ * Based on arch/arm/kernel/asm-offsets.c
+ *
+ * Copyright (C) 1995-2003 Russell King
+ *               2001-2002 Keith Owens
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/dma-mapping.h>
+#include <linux/kvm_host.h>
+#include <asm/thread_info.h>
+#include <asm/memory.h>
+#include <asm/cputable.h>
+#include <asm/smp_plat.h>
+#include <asm/suspend.h>
+#include <asm/vdso_datapage.h>
+#include <linux/kbuild.h>
+
+int main(void)
+{
+  DEFINE(TSK_ACTIVE_MM,		offsetof(struct task_struct, active_mm));
+  BLANK();
+  DEFINE(TI_FLAGS,		offsetof(struct thread_info, flags));
+  DEFINE(TI_PREEMPT,		offsetof(struct thread_info, preempt_count));
+  DEFINE(TI_ADDR_LIMIT,		offsetof(struct thread_info, addr_limit));
+  DEFINE(TI_TASK,		offsetof(struct thread_info, task));
+  DEFINE(TI_EXEC_DOMAIN,	offsetof(struct thread_info, exec_domain));
+  DEFINE(TI_CPU,		offsetof(struct thread_info, cpu));
+  BLANK();
+  DEFINE(THREAD_CPU_CONTEXT,	offsetof(struct task_struct, thread.cpu_context));
+  BLANK();
+  DEFINE(S_X0,			offsetof(struct pt_regs, regs[0]));
+  DEFINE(S_X1,			offsetof(struct pt_regs, regs[1]));
+  DEFINE(S_X2,			offsetof(struct pt_regs, regs[2]));
+  DEFINE(S_X3,			offsetof(struct pt_regs, regs[3]));
+  DEFINE(S_X4,			offsetof(struct pt_regs, regs[4]));
+  DEFINE(S_X5,			offsetof(struct pt_regs, regs[5]));
+  DEFINE(S_X6,			offsetof(struct pt_regs, regs[6]));
+  DEFINE(S_X7,			offsetof(struct pt_regs, regs[7]));
+  DEFINE(S_LR,			offsetof(struct pt_regs, regs[30]));
+  DEFINE(S_SP,			offsetof(struct pt_regs, sp));
+#ifdef CONFIG_COMPAT
+  DEFINE(S_COMPAT_SP,		offsetof(struct pt_regs, compat_sp));
+#endif
+  DEFINE(S_PSTATE,		offsetof(struct pt_regs, pstate));
+  DEFINE(S_PC,			offsetof(struct pt_regs, pc));
+  DEFINE(S_ORIG_X0,		offsetof(struct pt_regs, orig_x0));
+  DEFINE(S_SYSCALLNO,		offsetof(struct pt_regs, syscallno));
+  DEFINE(S_FRAME_SIZE,		sizeof(struct pt_regs));
+  BLANK();
+  DEFINE(MM_CONTEXT_ID,		offsetof(struct mm_struct, context.id));
+  BLANK();
+  DEFINE(VMA_VM_MM,		offsetof(struct vm_area_struct, vm_mm));
+  DEFINE(VMA_VM_FLAGS,		offsetof(struct vm_area_struct, vm_flags));
+  BLANK();
+  DEFINE(VM_EXEC,	       	VM_EXEC);
+  BLANK();
+  DEFINE(PAGE_SZ,	       	PAGE_SIZE);
+  BLANK();
+  DEFINE(CPU_INFO_SZ,		sizeof(struct cpu_info));
+  DEFINE(CPU_INFO_SETUP,	offsetof(struct cpu_info, cpu_setup));
+  BLANK();
+  DEFINE(DMA_BIDIRECTIONAL,	DMA_BIDIRECTIONAL);
+  DEFINE(DMA_TO_DEVICE,		DMA_TO_DEVICE);
+  DEFINE(DMA_FROM_DEVICE,	DMA_FROM_DEVICE);
+  BLANK();
+  DEFINE(CLOCK_REALTIME,	CLOCK_REALTIME);
+  DEFINE(CLOCK_MONOTONIC,	CLOCK_MONOTONIC);
+  DEFINE(CLOCK_REALTIME_RES,	MONOTONIC_RES_NSEC);
+  DEFINE(CLOCK_REALTIME_COARSE,	CLOCK_REALTIME_COARSE);
+  DEFINE(CLOCK_MONOTONIC_COARSE,CLOCK_MONOTONIC_COARSE);
+  DEFINE(CLOCK_COARSE_RES,	LOW_RES_NSEC);
+  DEFINE(NSEC_PER_SEC,		NSEC_PER_SEC);
+  BLANK();
+  DEFINE(VDSO_CS_CYCLE_LAST,	offsetof(struct vdso_data, cs_cycle_last));
+  DEFINE(VDSO_XTIME_CLK_SEC,	offsetof(struct vdso_data, xtime_clock_sec));
+  DEFINE(VDSO_XTIME_CLK_NSEC,	offsetof(struct vdso_data, xtime_clock_nsec));
+  DEFINE(VDSO_XTIME_CRS_SEC,	offsetof(struct vdso_data, xtime_coarse_sec));
+  DEFINE(VDSO_XTIME_CRS_NSEC,	offsetof(struct vdso_data, xtime_coarse_nsec));
+  DEFINE(VDSO_WTM_CLK_SEC,	offsetof(struct vdso_data, wtm_clock_sec));
+  DEFINE(VDSO_WTM_CLK_NSEC,	offsetof(struct vdso_data, wtm_clock_nsec));
+  DEFINE(VDSO_TB_SEQ_COUNT,	offsetof(struct vdso_data, tb_seq_count));
+  DEFINE(VDSO_CS_MULT,		offsetof(struct vdso_data, cs_mult));
+  DEFINE(VDSO_CS_SHIFT,		offsetof(struct vdso_data, cs_shift));
+  DEFINE(VDSO_TZ_MINWEST,	offsetof(struct vdso_data, tz_minuteswest));
+  DEFINE(VDSO_TZ_DSTTIME,	offsetof(struct vdso_data, tz_dsttime));
+  DEFINE(VDSO_USE_SYSCALL,	offsetof(struct vdso_data, use_syscall));
+  BLANK();
+  DEFINE(TVAL_TV_SEC,		offsetof(struct timeval, tv_sec));
+  DEFINE(TVAL_TV_USEC,		offsetof(struct timeval, tv_usec));
+  DEFINE(TSPEC_TV_SEC,		offsetof(struct timespec, tv_sec));
+  DEFINE(TSPEC_TV_NSEC,		offsetof(struct timespec, tv_nsec));
+  BLANK();
+  DEFINE(TZ_MINWEST,		offsetof(struct timezone, tz_minuteswest));
+  DEFINE(TZ_DSTTIME,		offsetof(struct timezone, tz_dsttime));
+  BLANK();
+#ifdef CONFIG_KVM_ARM_HOST
+  DEFINE(VCPU_CONTEXT,		offsetof(struct kvm_vcpu, arch.ctxt));
+  DEFINE(CPU_GP_REGS,		offsetof(struct kvm_cpu_context, gp_regs));
+  DEFINE(CPU_USER_PT_REGS,	offsetof(struct kvm_regs, regs));
+  DEFINE(CPU_FP_REGS,		offsetof(struct kvm_regs, fp_regs));
+  DEFINE(CPU_SP_EL1,		offsetof(struct kvm_regs, sp_el1));
+  DEFINE(CPU_ELR_EL1,		offsetof(struct kvm_regs, elr_el1));
+  DEFINE(CPU_SPSR,		offsetof(struct kvm_regs, spsr));
+  DEFINE(CPU_SYSREGS,		offsetof(struct kvm_cpu_context, sys_regs));
+  DEFINE(VCPU_ESR_EL2,		offsetof(struct kvm_vcpu, arch.fault.esr_el2));
+  DEFINE(VCPU_FAR_EL2,		offsetof(struct kvm_vcpu, arch.fault.far_el2));
+  DEFINE(VCPU_HPFAR_EL2,	offsetof(struct kvm_vcpu, arch.fault.hpfar_el2));
+  DEFINE(VCPU_DEBUG_FLAGS,	offsetof(struct kvm_vcpu, arch.debug_flags));
+  DEFINE(VCPU_HCR_EL2,		offsetof(struct kvm_vcpu, arch.hcr_el2));
+  DEFINE(VCPU_IRQ_LINES,	offsetof(struct kvm_vcpu, arch.irq_lines));
+  DEFINE(VCPU_HOST_CONTEXT,	offsetof(struct kvm_vcpu, arch.host_cpu_context));
+  DEFINE(VCPU_TIMER_CNTV_CTL,	offsetof(struct kvm_vcpu, arch.timer_cpu.cntv_ctl));
+  DEFINE(VCPU_TIMER_CNTV_CVAL,	offsetof(struct kvm_vcpu, arch.timer_cpu.cntv_cval));
+  DEFINE(KVM_TIMER_CNTVOFF,	offsetof(struct kvm, arch.timer.cntvoff));
+  DEFINE(KVM_TIMER_ENABLED,	offsetof(struct kvm, arch.timer.enabled));
+  DEFINE(VCPU_KVM,		offsetof(struct kvm_vcpu, kvm));
+  DEFINE(VCPU_VGIC_CPU,		offsetof(struct kvm_vcpu, arch.vgic_cpu));
+  DEFINE(VGIC_SAVE_FN,		offsetof(struct vgic_sr_vectors, save_vgic));
+  DEFINE(VGIC_RESTORE_FN,	offsetof(struct vgic_sr_vectors, restore_vgic));
+  DEFINE(VGIC_SR_VECTOR_SZ,	sizeof(struct vgic_sr_vectors));
+  DEFINE(VGIC_V2_CPU_HCR,	offsetof(struct vgic_cpu, vgic_v2.vgic_hcr));
+  DEFINE(VGIC_V2_CPU_VMCR,	offsetof(struct vgic_cpu, vgic_v2.vgic_vmcr));
+  DEFINE(VGIC_V2_CPU_MISR,	offsetof(struct vgic_cpu, vgic_v2.vgic_misr));
+  DEFINE(VGIC_V2_CPU_EISR,	offsetof(struct vgic_cpu, vgic_v2.vgic_eisr));
+  DEFINE(VGIC_V2_CPU_ELRSR,	offsetof(struct vgic_cpu, vgic_v2.vgic_elrsr));
+  DEFINE(VGIC_V2_CPU_APR,	offsetof(struct vgic_cpu, vgic_v2.vgic_apr));
+  DEFINE(VGIC_V2_CPU_LR,	offsetof(struct vgic_cpu, vgic_v2.vgic_lr));
+  DEFINE(VGIC_V3_CPU_HCR,	offsetof(struct vgic_cpu, vgic_v3.vgic_hcr));
+  DEFINE(VGIC_V3_CPU_VMCR,	offsetof(struct vgic_cpu, vgic_v3.vgic_vmcr));
+  DEFINE(VGIC_V3_CPU_MISR,	offsetof(struct vgic_cpu, vgic_v3.vgic_misr));
+  DEFINE(VGIC_V3_CPU_EISR,	offsetof(struct vgic_cpu, vgic_v3.vgic_eisr));
+  DEFINE(VGIC_V3_CPU_ELRSR,	offsetof(struct vgic_cpu, vgic_v3.vgic_elrsr));
+  DEFINE(VGIC_V3_CPU_AP0R,	offsetof(struct vgic_cpu, vgic_v3.vgic_ap0r));
+  DEFINE(VGIC_V3_CPU_AP1R,	offsetof(struct vgic_cpu, vgic_v3.vgic_ap1r));
+  DEFINE(VGIC_V3_CPU_LR,	offsetof(struct vgic_cpu, vgic_v3.vgic_lr));
+  DEFINE(VGIC_CPU_NR_LR,	offsetof(struct vgic_cpu, nr_lr));
+  DEFINE(KVM_VTTBR,		offsetof(struct kvm, arch.vttbr));
+  DEFINE(KVM_VGIC_VCTRL,	offsetof(struct kvm, arch.vgic.vctrl_base));
+#endif
+#ifdef CONFIG_ARM64_CPU_SUSPEND
+  DEFINE(CPU_SUSPEND_SZ,	sizeof(struct cpu_suspend_ctx));
+  DEFINE(CPU_CTX_SP,		offsetof(struct cpu_suspend_ctx, sp));
+  DEFINE(MPIDR_HASH_MASK,	offsetof(struct mpidr_hash, mask));
+  DEFINE(MPIDR_HASH_SHIFTS,	offsetof(struct mpidr_hash, shift_aff));
+  DEFINE(SLEEP_SAVE_SP_SZ,	sizeof(struct sleep_save_sp));
+  DEFINE(SLEEP_SAVE_SP_PHYS,	offsetof(struct sleep_save_sp, save_ptr_stash_phys));
+  DEFINE(SLEEP_SAVE_SP_VIRT,	offsetof(struct sleep_save_sp, save_ptr_stash));
+#endif
+  return 0;
+}

arch/arm64/kernel/cpu_errata.c

@@ -0,0 +1,120 @@
+/*
+ * Contains CPU specific errata definitions
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define pr_fmt(fmt) "alternative: " fmt
+
+#include <linux/types.h>
+#include <asm/cpu.h>
+#include <asm/cputype.h>
+#include <asm/cpufeature.h>
+
+#define MIDR_CORTEX_A53 MIDR_CPU_PART(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A53)
+#define MIDR_CORTEX_A57 MIDR_CPU_PART(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A57)
+
+/*
+ * Add a struct or another datatype to the union below if you need
+ * different means to detect an affected CPU.
+ */
+struct arm64_cpu_capabilities {
+	const char *desc;
+	u16 capability;
+	bool (*is_affected)(struct arm64_cpu_capabilities *);
+	union {
+		struct {
+			u32 midr_model;
+			u32 midr_range_min, midr_range_max;
+		};
+	};
+};
+
+#define CPU_MODEL_MASK (MIDR_IMPLEMENTOR_MASK | MIDR_PARTNUM_MASK | \
+			MIDR_ARCHITECTURE_MASK)
+
+static bool __maybe_unused
+is_affected_midr_range(struct arm64_cpu_capabilities *entry)
+{
+	u32 midr = read_cpuid_id();
+
+	if ((midr & CPU_MODEL_MASK) != entry->midr_model)
+		return false;
+
+	midr &= MIDR_REVISION_MASK | MIDR_VARIANT_MASK;
+
+	return (midr >= entry->midr_range_min && midr <= entry->midr_range_max);
+}
+
+#define MIDR_RANGE(model, min, max) \
+	.is_affected = is_affected_midr_range, \
+	.midr_model = model, \
+	.midr_range_min = min, \
+	.midr_range_max = max
+
+struct arm64_cpu_capabilities arm64_errata[] = {
+#if	defined(CONFIG_ARM64_ERRATUM_826319) || \
+	defined(CONFIG_ARM64_ERRATUM_827319) || \
+	defined(CONFIG_ARM64_ERRATUM_824069)
+	{
+	/* Cortex-A53 r0p[012] */
+		.desc = "ARM errata 826319, 827319, 824069",
+		.capability = ARM64_WORKAROUND_CLEAN_CACHE,
+		MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x02),
+	},
+#endif
+#ifdef CONFIG_ARM64_ERRATUM_819472
+	{
+	/* Cortex-A53 r0p[01] */
+		.desc = "ARM errata 819472",
+		.capability = ARM64_WORKAROUND_CLEAN_CACHE,
+		MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x01),
+	},
+#endif
+#ifdef CONFIG_ARM64_ERRATUM_832075
+	{
+	/* Cortex-A57 r0p0 - r1p2 */
+		.desc = "ARM erratum 832075",
+		.capability = ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE,
+		MIDR_RANGE(MIDR_CORTEX_A57, 0x00,
+			   (1 << MIDR_VARIANT_SHIFT) | 2),
+	},
+#endif
+#ifdef CONFIG_ARM64_ERRATUM_845719
+	{
+	/* Cortex-A53 r0p[01234] */
+		.desc = "ARM erratum 845719",
+		.capability = ARM64_WORKAROUND_845719,
+		MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x04),
+	},
+#endif
+	{
+	}
+};
+
+void check_local_cpu_errata(void)
+{
+	struct arm64_cpu_capabilities *cpus = arm64_errata;
+	int i;
+
+	for (i = 0; cpus[i].desc; i++) {
+		if (!cpus[i].is_affected(&cpus[i]))
+			continue;
+
+		if (!cpus_have_cap(cpus[i].capability))
+			pr_info("enabling workaround for %s\n", cpus[i].desc);
+		cpus_set_cap(cpus[i].capability);
+	}
+}

arch/arm64/kernel/cpu_ops.c

@@ -0,0 +1,87 @@
+/*
+ * CPU kernel entry/exit control
+ *
+ * Copyright (C) 2013 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <asm/cpu_ops.h>
+#include <asm/smp_plat.h>
+#include <linux/errno.h>
+#include <linux/of.h>
+#include <linux/string.h>
+
+extern const struct cpu_operations smp_spin_table_ops;
+extern const struct cpu_operations cpu_psci_ops;
+
+const struct cpu_operations *cpu_ops[NR_CPUS];
+
+static const struct cpu_operations *supported_cpu_ops[] __initconst = {
+#ifdef CONFIG_SMP
+	&smp_spin_table_ops,
+#endif
+	&cpu_psci_ops,
+	NULL,
+};
+
+static const struct cpu_operations * __init cpu_get_ops(const char *name)
+{
+	const struct cpu_operations **ops = supported_cpu_ops;
+
+	while (*ops) {
+		if (!strcmp(name, (*ops)->name))
+			return *ops;
+
+		ops++;
+	}
+
+	return NULL;
+}
+
+/*
+ * Read a cpu's enable method from the device tree and record it in cpu_ops.
+ */
+int __init cpu_read_ops(struct device_node *dn, int cpu)
+{
+	const char *enable_method = of_get_property(dn, "enable-method", NULL);
+	if (!enable_method) {
+		/*
+		 * The boot CPU may not have an enable method (e.g. when
+		 * spin-table is used for secondaries). Don't warn spuriously.
+		 */
+		if (cpu != 0)
+			pr_err("%s: missing enable-method property\n",
+				dn->full_name);
+		return -ENOENT;
+	}
+
+	cpu_ops[cpu] = cpu_get_ops(enable_method);
+	if (!cpu_ops[cpu]) {
+		pr_warn("%s: unsupported enable-method property: %s\n",
+			dn->full_name, enable_method);
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+void __init cpu_read_bootcpu_ops(void)
+{
+	struct device_node *dn = of_get_cpu_node(0, NULL);
+	if (!dn) {
+		pr_err("Failed to find device node for boot cpu\n");
+		return;
+	}
+	cpu_read_ops(dn, 0);
+}

arch/arm64/kernel/cpuidle.c

@@ -0,0 +1,31 @@
+/*
+ * ARM64 CPU idle arch support
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include <asm/cpuidle.h>
+#include <asm/cpu_ops.h>
+
+int cpu_init_idle(unsigned int cpu)
+{
+	int ret = -EOPNOTSUPP;
+	struct device_node *cpu_node = of_cpu_device_node_get(cpu);
+
+	if (!cpu_node)
+		return -ENODEV;
+
+	if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_init_idle)
+		ret = cpu_ops[cpu]->cpu_init_idle(cpu_node, cpu);
+
+	of_node_put(cpu_node);
+	return ret;
+}

arch/arm64/kernel/cpuinfo.c

@@ -0,0 +1,251 @@
+/*
+ * Record and handle CPU attributes.
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <asm/arch_timer.h>
+#include <asm/cachetype.h>
+#include <asm/cpu.h>
+#include <asm/cputype.h>
+#include <asm/cpufeature.h>
+#include <asm/smp_plat.h>
+
+#include <linux/bitops.h>
+#include <linux/bug.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/preempt.h>
+#include <linux/printk.h>
+#include <linux/smp.h>
+
+/*
+ * In case the boot CPU is hotpluggable, we record its initial state and
+ * current state separately. Certain system registers may contain different
+ * values depending on configuration at or after reset.
+ */
+DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
+static struct cpuinfo_arm64 boot_cpu_data;
+static bool mixed_endian_el0 = true;
+
+bool cpu_supports_mixed_endian_el0(void)
+{
+	return id_aa64mmfr0_mixed_endian_el0(read_cpuid(ID_AA64MMFR0_EL1));
+}
+
+bool system_supports_mixed_endian_el0(void)
+{
+	return mixed_endian_el0;
+}
+
+static void update_mixed_endian_el0_support(struct cpuinfo_arm64 *info)
+{
+	mixed_endian_el0 &= id_aa64mmfr0_mixed_endian_el0(info->reg_id_aa64mmfr0);
+}
+
+static void update_cpu_features(struct cpuinfo_arm64 *info)
+{
+	update_mixed_endian_el0_support(info);
+}
+
+static char *icache_policy_str[] = {
+	[ICACHE_POLICY_RESERVED] = "RESERVED/UNKNOWN",
+	[ICACHE_POLICY_AIVIVT] = "AIVIVT",
+	[ICACHE_POLICY_VIPT] = "VIPT",
+	[ICACHE_POLICY_PIPT] = "PIPT",
+};
+
+unsigned long __icache_flags;
+
+static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
+{
+	unsigned int cpu = smp_processor_id();
+	u32 l1ip = CTR_L1IP(info->reg_ctr);
+
+	if (l1ip != ICACHE_POLICY_PIPT) {
+		/*
+		 * VIPT caches are non-aliasing if the VA always equals the PA
+		 * in all bit positions that are covered by the index. This is
+		 * the case if the size of a way (# of sets * line size) does
+		 * not exceed PAGE_SIZE.
+		 */
+		u32 waysize = icache_get_numsets() * icache_get_linesize();
+
+		if (l1ip != ICACHE_POLICY_VIPT || waysize > PAGE_SIZE)
+			set_bit(ICACHEF_ALIASING, &__icache_flags);
+	}
+	if (l1ip == ICACHE_POLICY_AIVIVT)
+		set_bit(ICACHEF_AIVIVT, &__icache_flags);
+
+	pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
+}
+
+static int check_reg_mask(char *name, u64 mask, u64 boot, u64 cur, int cpu)
+{
+	if ((boot & mask) == (cur & mask))
+		return 0;
+
+	pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016lx, CPU%d: %#016lx\n",
+		name, (unsigned long)boot, cpu, (unsigned long)cur);
+
+	return 1;
+}
+
+#define CHECK_MASK(field, mask, boot, cur, cpu) \
+	check_reg_mask(#field, mask, (boot)->reg_ ## field, (cur)->reg_ ## field, cpu)
+
+#define CHECK(field, boot, cur, cpu) \
+	CHECK_MASK(field, ~0ULL, boot, cur, cpu)
+
+/*
+ * Verify that CPUs don't have unexpected differences that will cause problems.
+ */
+static void cpuinfo_sanity_check(struct cpuinfo_arm64 *cur)
+{
+	unsigned int cpu = smp_processor_id();
+	struct cpuinfo_arm64 *boot = &boot_cpu_data;
+	unsigned int diff = 0;
+
+#ifdef CONFIG_SOC_EXYNOS8890
+	/*
+	 * HACK: In Exynos8890, the sanity check for cluster '0' is meaningless
+	 * because it consists of non-arm CPUs.
+	 */
+	if (!MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1))
+		return;
+#endif
+
+	/*
+	 * The kernel can handle differing I-cache policies, but otherwise
+	 * caches should look identical. Userspace JITs will make use of
+	 * *minLine.
+	 */
+	diff |= CHECK_MASK(ctr, 0xffff3fff, boot, cur, cpu);
+
+	/*
+	 * Userspace may perform DC ZVA instructions. Mismatched block sizes
+	 * could result in too much or too little memory being zeroed if a
+	 * process is preempted and migrated between CPUs.
+	 */
+	diff |= CHECK(dczid, boot, cur, cpu);
+
+	/* If different, timekeeping will be broken (especially with KVM) */
+	diff |= CHECK(cntfrq, boot, cur, cpu);
+
+	/*
+	 * Even in big.LITTLE, processors should be identical instruction-set
+	 * wise.
+	 */
+	diff |= CHECK(id_aa64isar0, boot, cur, cpu);
+	diff |= CHECK(id_aa64isar1, boot, cur, cpu);
+
+	/*
+	 * Differing PARange support is fine as long as all peripherals and
+	 * memory are mapped within the minimum PARange of all CPUs.
+	 * Linux should not care about secure memory.
+	 * ID_AA64MMFR1 is currently RES0.
+	 */
+	diff |= CHECK_MASK(id_aa64mmfr0, 0xffffffffffff0ff0, boot, cur, cpu);
+	diff |= CHECK(id_aa64mmfr1, boot, cur, cpu);
+
+	/*
+	 * EL3 is not our concern.
+	 * ID_AA64PFR1 is currently RES0.
+	 */
+	diff |= CHECK_MASK(id_aa64pfr0, 0xffffffffffff0fff, boot, cur, cpu);
+	diff |= CHECK(id_aa64pfr1, boot, cur, cpu);
+
+	/*
+	 * If we have AArch32, we care about 32-bit features for compat. These
+	 * registers should be RES0 otherwise.
+	 */
+	diff |= CHECK(id_isar0, boot, cur, cpu);
+	diff |= CHECK(id_isar1, boot, cur, cpu);
+	diff |= CHECK(id_isar2, boot, cur, cpu);
+	diff |= CHECK(id_isar3, boot, cur, cpu);
+	diff |= CHECK(id_isar4, boot, cur, cpu);
+	diff |= CHECK(id_isar5, boot, cur, cpu);
+	diff |= CHECK(id_mmfr0, boot, cur, cpu);
+	diff |= CHECK(id_mmfr1, boot, cur, cpu);
+	diff |= CHECK(id_mmfr2, boot, cur, cpu);
+	diff |= CHECK(id_mmfr3, boot, cur, cpu);
+	diff |= CHECK(id_pfr0, boot, cur, cpu);
+	diff |= CHECK(id_pfr1, boot, cur, cpu);
+
+	/*
+	 * Mismatched CPU features are a recipe for disaster. Don't even
+	 * pretend to support them.
+	 */
+	WARN_TAINT_ONCE(diff, TAINT_CPU_OUT_OF_SPEC,
+			"Unsupported CPU feature variation.");
+}
+
+static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
+{
+	info->reg_cntfrq = arch_timer_get_cntfrq();
+	info->reg_ctr = read_cpuid_cachetype();
+	info->reg_dczid = read_cpuid(DCZID_EL0);
+	info->reg_midr = read_cpuid_id();
+
+	info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1);
+	info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1);
+	info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
+	info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
+	info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
+	info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);
+
+	info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1);
+	info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1);
+	info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1);
+	info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1);
+	info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1);
+	info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1);
+	info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1);
+	info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1);
+	info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1);
+	info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1);
+	info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
+	info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);
+
+	cpuinfo_detect_icache_policy(info);
+	update_cpu_features(info);
+
+	check_local_cpu_errata();
+}
+
+void cpuinfo_store_cpu(void)
+{
+	struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
+	__cpuinfo_store_cpu(info);
+	cpuinfo_sanity_check(info);
+}
+
+void __init cpuinfo_store_boot_cpu(void)
+{
+	struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
+	__cpuinfo_store_cpu(info);
+
+	boot_cpu_data = *info;
+}
+
+u64 __attribute_const__ icache_get_ccsidr(void)
+{
+	u64 ccsidr;
+
+	WARN_ON(preemptible());
+
+	/* Select L1 I-cache and read its size ID register */
+	asm("msr csselr_el1, %1; isb; mrs %0, ccsidr_el1"
+	    : "=r"(ccsidr) : "r"(1L));
+	return ccsidr;
+}

arch/arm64/kernel/cputable.c

@@ -0,0 +1,33 @@
+/*
+ * arch/arm64/kernel/cputable.c
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/init.h>
+
+#include <asm/cputable.h>
+
+extern unsigned long __cpu_setup(void);
+
+struct cpu_info cpu_table[] = {
+	{
+		.cpu_id_val	= 0x000f0000,
+		.cpu_id_mask	= 0x000f0000,
+		.cpu_name	= "AArch64 Processor",
+		.cpu_setup	= __cpu_setup,
+	},
+	{ /* Empty */ },
+};

arch/arm64/kernel/debug-monitors.c

@@ -0,0 +1,429 @@
+/*
+ * ARMv8 single-step debug support and mdscr context switching.
+ *
+ * Copyright (C) 2012 ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#include <linux/cpu.h>
+#include <linux/debugfs.h>
+#include <linux/hardirq.h>
+#include <linux/init.h>
+#include <linux/ptrace.h>
+#include <linux/stat.h>
+#include <linux/uaccess.h>
+
+#include <asm/debug-monitors.h>
+#include <asm/cputype.h>
+#include <asm/system_misc.h>
+
+/* Determine debug architecture. */
+u8 debug_monitors_arch(void)
+{
+	return read_cpuid(ID_AA64DFR0_EL1) & 0xf;
+}
+
+/*
+ * MDSCR access routines.
+ */
+static void mdscr_write(u32 mdscr)
+{
+	unsigned long flags;
+	local_dbg_save(flags);
+	asm volatile("msr mdscr_el1, %0" :: "r" (mdscr));
+	local_dbg_restore(flags);
+}
+
+static u32 mdscr_read(void)
+{
+	u32 mdscr;
+	asm volatile("mrs %0, mdscr_el1" : "=r" (mdscr));
+	return mdscr;
+}
+
+/*
+ * Allow root to disable self-hosted debug from userspace.
+ * This is useful if you want to connect an external JTAG debugger.
+ */
+static u32 debug_enabled = 1;
+
+static int create_debug_debugfs_entry(void)
+{
+	debugfs_create_bool("debug_enabled", 0644, NULL, &debug_enabled);
+	return 0;
+}
+fs_initcall(create_debug_debugfs_entry);
+
+static int __init early_debug_disable(char *buf)
+{
+	debug_enabled = 0;
+	return 0;
+}
+
+early_param("nodebugmon", early_debug_disable);
+
+/*
+ * Keep track of debug users on each core.
+ * The ref counts are per-cpu so we use a local_t type.
+ */
+static DEFINE_PER_CPU(int, mde_ref_count);
+static DEFINE_PER_CPU(int, kde_ref_count);
+
+void enable_debug_monitors(enum debug_el el)
+{
+	u32 mdscr, enable = 0;
+
+	WARN_ON(preemptible());
+
+	if (this_cpu_inc_return(mde_ref_count) == 1)
+		enable = DBG_MDSCR_MDE;
+
+	if (el == DBG_ACTIVE_EL1 &&
+	    this_cpu_inc_return(kde_ref_count) == 1)
+		enable |= DBG_MDSCR_KDE;
+
+	if (enable && debug_enabled) {
+		mdscr = mdscr_read();
+		mdscr |= enable;
+		mdscr_write(mdscr);
+	}
+}
+
+void disable_debug_monitors(enum debug_el el)
+{
+	u32 mdscr, disable = 0;
+
+	WARN_ON(preemptible());
+
+	if (this_cpu_dec_return(mde_ref_count) == 0)
+		disable = ~DBG_MDSCR_MDE;
+
+	if (el == DBG_ACTIVE_EL1 &&
+	    this_cpu_dec_return(kde_ref_count) == 0)
+		disable &= ~DBG_MDSCR_KDE;
+
+	if (disable) {
+		mdscr = mdscr_read();
+		mdscr &= disable;
+		mdscr_write(mdscr);
+	}
+}
+
+/*
+ * OS lock clearing.
+ */
+static void clear_os_lock(void *unused)
+{
+	asm volatile("msr oslar_el1, %0" : : "r" (0));
+}
+
+static int os_lock_notify(struct notifier_block *self,
+				    unsigned long action, void *data)
+{
+	int cpu = (unsigned long)data;
+	if (action == CPU_ONLINE)
+		smp_call_function_single(cpu, clear_os_lock, NULL, 1);
+	return NOTIFY_OK;
+}
+
+static struct notifier_block os_lock_nb = {
+	.notifier_call = os_lock_notify,
+};
+
+static int debug_monitors_init(void)
+{
+	cpu_notifier_register_begin();
+
+	/* Clear the OS lock. */
+	on_each_cpu(clear_os_lock, NULL, 1);
+	isb();
+	local_dbg_enable();
+
+	/* Register hotplug handler. */
+	__register_cpu_notifier(&os_lock_nb);
+
+	cpu_notifier_register_done();
+	return 0;
+}
+postcore_initcall(debug_monitors_init);
+
+/*
+ * Single step API and exception handling.
+ */
+static void set_regs_spsr_ss(struct pt_regs *regs)
+{
+	unsigned long spsr;
+
+	spsr = regs->pstate;
+	spsr &= ~DBG_SPSR_SS;
+	spsr |= DBG_SPSR_SS;
+	regs->pstate = spsr;
+}
+
+static void clear_regs_spsr_ss(struct pt_regs *regs)
+{
+	unsigned long spsr;
+
+	spsr = regs->pstate;
+	spsr &= ~DBG_SPSR_SS;
+	regs->pstate = spsr;
+}
+
+/* EL1 Single Step Handler hooks */
+static LIST_HEAD(step_hook);
+static DEFINE_RWLOCK(step_hook_lock);
+
+void register_step_hook(struct step_hook *hook)
+{
+	write_lock(&step_hook_lock);
+	list_add(&hook->node, &step_hook);
+	write_unlock(&step_hook_lock);
+}
+
+void unregister_step_hook(struct step_hook *hook)
+{
+	write_lock(&step_hook_lock);
+	list_del(&hook->node);
+	write_unlock(&step_hook_lock);
+}
+
+/*
+ * Call registered single step handers
+ * There is no Syndrome info to check for determining the handler.
+ * So we call all the registered handlers, until the right handler is
+ * found which returns zero.
+ */
+static int call_step_hook(struct pt_regs *regs, unsigned int esr)
+{
+	struct step_hook *hook;
+	int retval = DBG_HOOK_ERROR;
+
+	read_lock(&step_hook_lock);
+
+	list_for_each_entry(hook, &step_hook, node)	{
+		retval = hook->fn(regs, esr);
+		if (retval == DBG_HOOK_HANDLED)
+			break;
+	}
+
+	read_unlock(&step_hook_lock);
+
+	return retval;
+}
+
+static int single_step_handler(unsigned long addr, unsigned int esr,
+			       struct pt_regs *regs)
+{
+	siginfo_t info;
+
+	/*
+	 * If we are stepping a pending breakpoint, call the hw_breakpoint
+	 * handler first.
+	 */
+	if (!reinstall_suspended_bps(regs))
+		return 0;
+
+	if (user_mode(regs)) {
+		info.si_signo = SIGTRAP;
+		info.si_errno = 0;
+		info.si_code  = TRAP_HWBKPT;
+		info.si_addr  = (void __user *)instruction_pointer(regs);
+		force_sig_info(SIGTRAP, &info, current);
+
+		/*
+		 * ptrace will disable single step unless explicitly
+		 * asked to re-enable it. For other clients, it makes
+		 * sense to leave it enabled (i.e. rewind the controls
+		 * to the active-not-pending state).
+		 */
+		user_rewind_single_step(current);
+	} else {
+		if (call_step_hook(regs, esr) == DBG_HOOK_HANDLED)
+			return 0;
+
+		pr_warning("Unexpected kernel single-step exception at EL1\n");
+		/*
+		 * Re-enable stepping since we know that we will be
+		 * returning to regs.
+		 */
+		set_regs_spsr_ss(regs);
+	}
+
+	return 0;
+}
+
+/*
+ * Breakpoint handler is re-entrant as another breakpoint can
+ * hit within breakpoint handler, especically in kprobes.
+ * Use reader/writer locks instead of plain spinlock.
+ */
+static LIST_HEAD(break_hook);
+static DEFINE_RWLOCK(break_hook_lock);
+
+void register_break_hook(struct break_hook *hook)
+{
+	write_lock(&break_hook_lock);
+	list_add(&hook->node, &break_hook);
+	write_unlock(&break_hook_lock);
+}
+
+void unregister_break_hook(struct break_hook *hook)
+{
+	write_lock(&break_hook_lock);
+	list_del(&hook->node);
+	write_unlock(&break_hook_lock);
+}
+
+static int call_break_hook(struct pt_regs *regs, unsigned int esr)
+{
+	struct break_hook *hook;
+	int (*fn)(struct pt_regs *regs, unsigned int esr) = NULL;
+
+	read_lock(&break_hook_lock);
+	list_for_each_entry(hook, &break_hook, node)
+		if ((esr & hook->esr_mask) == hook->esr_val)
+			fn = hook->fn;
+	read_unlock(&break_hook_lock);
+
+	return fn ? fn(regs, esr) : DBG_HOOK_ERROR;
+}
+
+static int brk_handler(unsigned long addr, unsigned int esr,
+		       struct pt_regs *regs)
+{
+	siginfo_t info;
+
+	if (user_mode(regs)) {
+		info = (siginfo_t) {
+			.si_signo = SIGTRAP,
+			.si_errno = 0,
+			.si_code  = TRAP_BRKPT,
+			.si_addr  = (void __user *)instruction_pointer(regs),
+		};
+
+		force_sig_info(SIGTRAP, &info, current);
+	} else if (call_break_hook(regs, esr) != DBG_HOOK_HANDLED) {
+		pr_warning("Unexpected kernel BRK exception at EL1\n");
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+int aarch32_break_handler(struct pt_regs *regs)
+{
+	siginfo_t info;
+	u32 arm_instr;
+	u16 thumb_instr;
+	bool bp = false;
+	void __user *pc = (void __user *)instruction_pointer(regs);
+
+	if (!compat_user_mode(regs))
+		return -EFAULT;
+
+	if (compat_thumb_mode(regs)) {
+		/* get 16-bit Thumb instruction */
+		get_user(thumb_instr, (u16 __user *)pc);
+		thumb_instr = le16_to_cpu(thumb_instr);
+		if (thumb_instr == AARCH32_BREAK_THUMB2_LO) {
+			/* get second half of 32-bit Thumb-2 instruction */
+			get_user(thumb_instr, (u16 __user *)(pc + 2));
+			thumb_instr = le16_to_cpu(thumb_instr);
+			bp = thumb_instr == AARCH32_BREAK_THUMB2_HI;
+		} else {
+			bp = thumb_instr == AARCH32_BREAK_THUMB;
+		}
+	} else {
+		/* 32-bit ARM instruction */
+		get_user(arm_instr, (u32 __user *)pc);
+		arm_instr = le32_to_cpu(arm_instr);
+		bp = (arm_instr & ~0xf0000000) == AARCH32_BREAK_ARM;
+	}
+
+	if (!bp)
+		return -EFAULT;
+
+	info = (siginfo_t) {
+		.si_signo = SIGTRAP,
+		.si_errno = 0,
+		.si_code  = TRAP_BRKPT,
+		.si_addr  = pc,
+	};
+
+	force_sig_info(SIGTRAP, &info, current);
+	return 0;
+}
+
+static int __init debug_traps_init(void)
+{
+	hook_debug_fault_code(DBG_ESR_EVT_HWSS, single_step_handler, SIGTRAP,
+			      TRAP_HWBKPT, "single-step handler");
+	hook_debug_fault_code(DBG_ESR_EVT_BRK, brk_handler, SIGTRAP,
+			      TRAP_BRKPT, "ptrace BRK handler");
+	return 0;
+}
+arch_initcall(debug_traps_init);
+
+/* Re-enable single step for syscall restarting. */
+void user_rewind_single_step(struct task_struct *task)
+{
+	/*
+	 * If single step is active for this thread, then set SPSR.SS
+	 * to 1 to avoid returning to the active-pending state.
+	 */
+	if (test_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP))
+		set_regs_spsr_ss(task_pt_regs(task));
+}
+
+void user_fastforward_single_step(struct task_struct *task)
+{
+	if (test_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP))
+		clear_regs_spsr_ss(task_pt_regs(task));
+}
+
+/* Kernel API */
+void kernel_enable_single_step(struct pt_regs *regs)
+{
+	WARN_ON(!irqs_disabled());
+	set_regs_spsr_ss(regs);
+	mdscr_write(mdscr_read() | DBG_MDSCR_SS);
+	enable_debug_monitors(DBG_ACTIVE_EL1);
+}
+
+void kernel_disable_single_step(void)
+{
+	WARN_ON(!irqs_disabled());
+	mdscr_write(mdscr_read() & ~DBG_MDSCR_SS);
+	disable_debug_monitors(DBG_ACTIVE_EL1);
+}
+
+int kernel_active_single_step(void)
+{
+	WARN_ON(!irqs_disabled());
+	return mdscr_read() & DBG_MDSCR_SS;
+}
+
+/* ptrace API */
+void user_enable_single_step(struct task_struct *task)
+{
+	set_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP);
+	set_regs_spsr_ss(task_pt_regs(task));
+}
+
+void user_disable_single_step(struct task_struct *task)
+{
+	clear_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP);
+}

arch/arm64/kernel/efi-entry.S

@@ -0,0 +1,123 @@
+/*
+ * EFI entry point.
+ *
+ * Copyright (C) 2013, 2014 Red Hat, Inc.
+ * Author: Mark Salter <msalter@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+#include <asm/assembler.h>
+
+#define EFI_LOAD_ERROR 0x8000000000000001
+
+	__INIT
+
+	/*
+	 * We arrive here from the EFI boot manager with:
+	 *
+	 *    * CPU in little-endian mode
+	 *    * MMU on with identity-mapped RAM
+	 *    * Icache and Dcache on
+	 *
+	 * We will most likely be running from some place other than where
+	 * we want to be. The kernel image wants to be placed at TEXT_OFFSET
+	 * from start of RAM.
+	 */
+ENTRY(efi_stub_entry)
+	/*
+	 * Create a stack frame to save FP/LR with extra space
+	 * for image_addr variable passed to efi_entry().
+	 */
+	stp	x29, x30, [sp, #-32]!
+
+	/*
+	 * Call efi_entry to do the real work.
+	 * x0 and x1 are already set up by firmware. Current runtime
+	 * address of image is calculated and passed via *image_addr.
+	 *
+	 * unsigned long efi_entry(void *handle,
+	 *                         efi_system_table_t *sys_table,
+	 *                         unsigned long *image_addr) ;
+	 */
+	adrp	x8, _text
+	add	x8, x8, #:lo12:_text
+	add	x2, sp, 16
+	str	x8, [x2]
+	bl	efi_entry
+	cmn	x0, #1
+	b.eq	efi_load_fail
+
+	/*
+	 * efi_entry() will have copied the kernel image if necessary and we
+	 * return here with device tree address in x0 and the kernel entry
+	 * point stored at *image_addr. Save those values in registers which
+	 * are callee preserved.
+	 */
+	mov	x20, x0		// DTB address
+	ldr	x0, [sp, #16]	// relocated _text address
+	mov	x21, x0
+
+	/*
+	 * Calculate size of the kernel Image (same for original and copy).
+	 */
+	adrp	x1, _text
+	add	x1, x1, #:lo12:_text
+	adrp	x2, _edata
+	add	x2, x2, #:lo12:_edata
+	sub	x1, x2, x1
+
+	/*
+	 * Flush the copied Image to the PoC, and ensure it is not shadowed by
+	 * stale icache entries from before relocation.
+	 */
+	bl	__flush_dcache_area
+	ic	ialluis
+
+	/*
+	 * Ensure that the rest of this function (in the original Image) is
+	 * visible when the caches are disabled. The I-cache can't have stale
+	 * entries for the VA range of the current image, so no maintenance is
+	 * necessary.
+	 */
+	adr	x0, efi_stub_entry
+	adr	x1, efi_stub_entry_end
+	sub	x1, x1, x0
+	bl	__flush_dcache_area
+
+	/* Turn off Dcache and MMU */
+	mrs	x0, CurrentEL
+	cmp	x0, #CurrentEL_EL2
+	b.ne	1f
+	mrs	x0, sctlr_el2
+	bic	x0, x0, #1 << 0	// clear SCTLR.M
+	bic	x0, x0, #1 << 2	// clear SCTLR.C
+	msr	sctlr_el2, x0
+	isb
+	b	2f
+1:
+	mrs	x0, sctlr_el1
+	bic	x0, x0, #1 << 0	// clear SCTLR.M
+	bic	x0, x0, #1 << 2	// clear SCTLR.C
+	msr	sctlr_el1, x0
+	isb
+2:
+	/* Jump to kernel entry point */
+	mov	x0, x20
+	mov	x1, xzr
+	mov	x2, xzr
+	mov	x3, xzr
+	br	x21
+
+efi_load_fail:
+	mov	x0, #EFI_LOAD_ERROR
+	ldp	x29, x30, [sp], #32
+	ret
+
+efi_stub_entry_end:
+ENDPROC(efi_stub_entry)

arch/arm64/kernel/efi-stub.c

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2013, 2014 Linaro Ltd;  <roy.franz@linaro.org>
+ *
+ * This file implements the EFI boot stub for the arm64 kernel.
+ * Adapted from ARM version by Mark Salter <msalter@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/efi.h>
+#include <asm/efi.h>
+#include <asm/sections.h>
+
+efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
+				 unsigned long *image_addr,
+				 unsigned long *image_size,
+				 unsigned long *reserve_addr,
+				 unsigned long *reserve_size,
+				 unsigned long dram_base,
+				 efi_loaded_image_t *image)
+{
+	efi_status_t status;
+	unsigned long kernel_size, kernel_memsize = 0;
+
+	/* Relocate the image, if required. */
+	kernel_size = _edata - _text;
+	if (*image_addr != (dram_base + TEXT_OFFSET)) {
+		kernel_memsize = kernel_size + (_end - _edata);
+		status = efi_low_alloc(sys_table, kernel_memsize + TEXT_OFFSET,
+				       SZ_2M, reserve_addr);
+		if (status != EFI_SUCCESS) {
+			pr_efi_err(sys_table, "Failed to relocate kernel\n");
+			return status;
+		}
+		memcpy((void *)*reserve_addr + TEXT_OFFSET, (void *)*image_addr,
+		       kernel_size);
+		*image_addr = *reserve_addr + TEXT_OFFSET;
+		*reserve_size = kernel_memsize + TEXT_OFFSET;
+	}
+
+
+	return EFI_SUCCESS;
+}

arch/arm64/kernel/efi.c

@@ -0,0 +1,473 @@
+/*
+ * Extensible Firmware Interface
+ *
+ * Based on Extensible Firmware Interface Specification version 2.4
+ *
+ * Copyright (C) 2013, 2014 Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/efi.h>
+#include <linux/export.h>
+#include <linux/memblock.h>
+#include <linux/bootmem.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include <asm/cacheflush.h>
+#include <asm/efi.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+
+struct efi_memory_map memmap;
+
+static efi_runtime_services_t *runtime;
+
+static u64 efi_system_table;
+
+static int uefi_debug __initdata;
+static int __init uefi_debug_setup(char *str)
+{
+	uefi_debug = 1;
+
+	return 0;
+}
+early_param("uefi_debug", uefi_debug_setup);
+
+static int __init is_normal_ram(efi_memory_desc_t *md)
+{
+	if (md->attribute & EFI_MEMORY_WB)
+		return 1;
+	return 0;
+}
+
+static void __init efi_setup_idmap(void)
+{
+	struct memblock_region *r;
+	efi_memory_desc_t *md;
+	u64 paddr, npages, size;
+
+	for_each_memblock(memory, r)
+		create_id_mapping(r->base, r->size, 0);
+
+	/* map runtime io spaces */
+	for_each_efi_memory_desc(&memmap, md) {
+		if (!(md->attribute & EFI_MEMORY_RUNTIME) || is_normal_ram(md))
+			continue;
+		paddr = md->phys_addr;
+		npages = md->num_pages;
+		memrange_efi_to_native(&paddr, &npages);
+		size = npages << PAGE_SHIFT;
+		create_id_mapping(paddr, size, 1);
+	}
+}
+
+static int __init uefi_init(void)
+{
+	efi_char16_t *c16;
+	char vendor[100] = "unknown";
+	int i, retval;
+
+	efi.systab = early_memremap(efi_system_table,
+				    sizeof(efi_system_table_t));
+	if (efi.systab == NULL) {
+		pr_warn("Unable to map EFI system table.\n");
+		return -ENOMEM;
+	}
+
+	set_bit(EFI_BOOT, &efi.flags);
+	set_bit(EFI_64BIT, &efi.flags);
+
+	/*
+	 * Verify the EFI Table
+	 */
+	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
+		pr_err("System table signature incorrect\n");
+		retval = -EINVAL;
+		goto out;
+	}
+	if ((efi.systab->hdr.revision >> 16) < 2)
+		pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
+			efi.systab->hdr.revision >> 16,
+			efi.systab->hdr.revision & 0xffff);
+
+	/* Show what we know for posterity */
+	c16 = early_memremap(efi.systab->fw_vendor,
+			     sizeof(vendor));
+	if (c16) {
+		for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
+			vendor[i] = c16[i];
+		vendor[i] = '\0';
+		early_memunmap(c16, sizeof(vendor));
+	}
+
+	pr_info("EFI v%u.%.02u by %s\n",
+		efi.systab->hdr.revision >> 16,
+		efi.systab->hdr.revision & 0xffff, vendor);
+
+	retval = efi_config_init(NULL);
+	if (retval == 0)
+		set_bit(EFI_CONFIG_TABLES, &efi.flags);
+
+out:
+	early_memunmap(efi.systab,  sizeof(efi_system_table_t));
+	return retval;
+}
+
+/*
+ * Return true for RAM regions we want to permanently reserve.
+ */
+static __init int is_reserve_region(efi_memory_desc_t *md)
+{
+	if (!is_normal_ram(md))
+		return 0;
+
+	if (md->attribute & EFI_MEMORY_RUNTIME)
+		return 1;
+
+	if (md->type == EFI_ACPI_RECLAIM_MEMORY ||
+	    md->type == EFI_RESERVED_TYPE)
+		return 1;
+
+	return 0;
+}
+
+static __init void reserve_regions(void)
+{
+	efi_memory_desc_t *md;
+	u64 paddr, npages, size;
+
+	if (uefi_debug)
+		pr_info("Processing EFI memory map:\n");
+
+	for_each_efi_memory_desc(&memmap, md) {
+		paddr = md->phys_addr;
+		npages = md->num_pages;
+
+		if (uefi_debug) {
+			char buf[64];
+
+			pr_info("  0x%012llx-0x%012llx %s",
+				paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
+				efi_md_typeattr_format(buf, sizeof(buf), md));
+		}
+
+		memrange_efi_to_native(&paddr, &npages);
+		size = npages << PAGE_SHIFT;
+
+		if (is_normal_ram(md))
+			early_init_dt_add_memory_arch(paddr, size);
+
+		if (is_reserve_region(md) ||
+		    md->type == EFI_BOOT_SERVICES_CODE ||
+		    md->type == EFI_BOOT_SERVICES_DATA) {
+			memblock_reserve(paddr, size);
+			if (uefi_debug)
+				pr_cont("*");
+		}
+
+		if (uefi_debug)
+			pr_cont("\n");
+	}
+
+	set_bit(EFI_MEMMAP, &efi.flags);
+}
+
+
+static u64 __init free_one_region(u64 start, u64 end)
+{
+	u64 size = end - start;
+
+	if (uefi_debug)
+		pr_info("  EFI freeing: 0x%012llx-0x%012llx\n",	start, end - 1);
+
+	free_bootmem_late(start, size);
+	return size;
+}
+
+static u64 __init free_region(u64 start, u64 end)
+{
+	u64 map_start, map_end, total = 0;
+
+	if (end <= start)
+		return total;
+
+	map_start = (u64)memmap.phys_map;
+	map_end = PAGE_ALIGN(map_start + (memmap.map_end - memmap.map));
+	map_start &= PAGE_MASK;
+
+	if (start < map_end && end > map_start) {
+		/* region overlaps UEFI memmap */
+		if (start < map_start)
+			total += free_one_region(start, map_start);
+
+		if (map_end < end)
+			total += free_one_region(map_end, end);
+	} else
+		total += free_one_region(start, end);
+
+	return total;
+}
+
+static void __init free_boot_services(void)
+{
+	u64 total_freed = 0;
+	u64 keep_end, free_start, free_end;
+	efi_memory_desc_t *md;
+
+	/*
+	 * If kernel uses larger pages than UEFI, we have to be careful
+	 * not to inadvertantly free memory we want to keep if there is
+	 * overlap at the kernel page size alignment. We do not want to
+	 * free is_reserve_region() memory nor the UEFI memmap itself.
+	 *
+	 * The memory map is sorted, so we keep track of the end of
+	 * any previous region we want to keep, remember any region
+	 * we want to free and defer freeing it until we encounter
+	 * the next region we want to keep. This way, before freeing
+	 * it, we can clip it as needed to avoid freeing memory we
+	 * want to keep for UEFI.
+	 */
+
+	keep_end = 0;
+	free_start = 0;
+
+	for_each_efi_memory_desc(&memmap, md) {
+		u64 paddr, npages, size;
+
+		if (is_reserve_region(md)) {
+			/*
+			 * We don't want to free any memory from this region.
+			 */
+			if (free_start) {
+				/* adjust free_end then free region */
+				if (free_end > md->phys_addr)
+					free_end -= PAGE_SIZE;
+				total_freed += free_region(free_start, free_end);
+				free_start = 0;
+			}
+			keep_end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
+			continue;
+		}
+
+		if (md->type != EFI_BOOT_SERVICES_CODE &&
+		    md->type != EFI_BOOT_SERVICES_DATA) {
+			/* no need to free this region */
+			continue;
+		}
+
+		/*
+		 * We want to free memory from this region.
+		 */
+		paddr = md->phys_addr;
+		npages = md->num_pages;
+		memrange_efi_to_native(&paddr, &npages);
+		size = npages << PAGE_SHIFT;
+
+		if (free_start) {
+			if (paddr <= free_end)
+				free_end = paddr + size;
+			else {
+				total_freed += free_region(free_start, free_end);
+				free_start = paddr;
+				free_end = paddr + size;
+			}
+		} else {
+			free_start = paddr;
+			free_end = paddr + size;
+		}
+		if (free_start < keep_end) {
+			free_start += PAGE_SIZE;
+			if (free_start >= free_end)
+				free_start = 0;
+		}
+	}
+	if (free_start)
+		total_freed += free_region(free_start, free_end);
+
+	if (total_freed)
+		pr_info("Freed 0x%llx bytes of EFI boot services memory",
+			total_freed);
+}
+
+void __init efi_init(void)
+{
+	struct efi_fdt_params params;
+
+	/* Grab UEFI information placed in FDT by stub */
+	if (!efi_get_fdt_params(&params, uefi_debug))
+		return;
+
+	efi_system_table = params.system_table;
+
+	memblock_reserve(params.mmap & PAGE_MASK,
+			 PAGE_ALIGN(params.mmap_size + (params.mmap & ~PAGE_MASK)));
+	memmap.phys_map = (void *)params.mmap;
+	memmap.map = early_memremap(params.mmap, params.mmap_size);
+	memmap.map_end = memmap.map + params.mmap_size;
+	memmap.desc_size = params.desc_size;
+	memmap.desc_version = params.desc_ver;
+
+	if (uefi_init() < 0)
+		return;
+
+	reserve_regions();
+}
+
+void __init efi_idmap_init(void)
+{
+	if (!efi_enabled(EFI_BOOT))
+		return;
+
+	/* boot time idmap_pg_dir is incomplete, so fill in missing parts */
+	efi_setup_idmap();
+	early_memunmap(memmap.map, memmap.map_end - memmap.map);
+}
+
+static int __init remap_region(efi_memory_desc_t *md, void **new)
+{
+	u64 paddr, vaddr, npages, size;
+
+	paddr = md->phys_addr;
+	npages = md->num_pages;
+	memrange_efi_to_native(&paddr, &npages);
+	size = npages << PAGE_SHIFT;
+
+	if (is_normal_ram(md))
+		vaddr = (__force u64)ioremap_cache(paddr, size);
+	else
+		vaddr = (__force u64)ioremap(paddr, size);
+
+	if (!vaddr) {
+		pr_err("Unable to remap 0x%llx pages @ %p\n",
+		       npages, (void *)paddr);
+		return 0;
+	}
+
+	/* adjust for any rounding when EFI and system pagesize differs */
+	md->virt_addr = vaddr + (md->phys_addr - paddr);
+
+	if (uefi_debug)
+		pr_info("  EFI remap 0x%012llx => %p\n",
+			md->phys_addr, (void *)md->virt_addr);
+
+	memcpy(*new, md, memmap.desc_size);
+	*new += memmap.desc_size;
+
+	return 1;
+}
+
+/*
+ * Switch UEFI from an identity map to a kernel virtual map
+ */
+static int __init arm64_enter_virtual_mode(void)
+{
+	efi_memory_desc_t *md;
+	phys_addr_t virtmap_phys;
+	void *virtmap, *virt_md;
+	efi_status_t status;
+	u64 mapsize;
+	int count = 0;
+	unsigned long flags;
+
+	if (!efi_enabled(EFI_BOOT)) {
+		pr_info("EFI services will not be available.\n");
+		return -1;
+	}
+
+	mapsize = memmap.map_end - memmap.map;
+
+	if (efi_runtime_disabled()) {
+		pr_info("EFI runtime services will be disabled.\n");
+		return -1;
+	}
+
+	pr_info("Remapping and enabling EFI services.\n");
+	/* replace early memmap mapping with permanent mapping */
+	memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
+						   mapsize);
+	memmap.map_end = memmap.map + mapsize;
+
+	efi.memmap = &memmap;
+
+	/* Map the runtime regions */
+	virtmap = kmalloc(mapsize, GFP_KERNEL);
+	if (!virtmap) {
+		pr_err("Failed to allocate EFI virtual memmap\n");
+		return -1;
+	}
+	virtmap_phys = virt_to_phys(virtmap);
+	virt_md = virtmap;
+
+	for_each_efi_memory_desc(&memmap, md) {
+		if (!(md->attribute & EFI_MEMORY_RUNTIME))
+			continue;
+		if (!remap_region(md, &virt_md))
+			goto err_unmap;
+		++count;
+	}
+
+	efi.systab = (__force void *)efi_lookup_mapped_addr(efi_system_table);
+	if (!efi.systab) {
+		/*
+		 * If we have no virtual mapping for the System Table at this
+		 * point, the memory map doesn't cover the physical offset where
+		 * it resides. This means the System Table will be inaccessible
+		 * to Runtime Services themselves once the virtual mapping is
+		 * installed.
+		 */
+		pr_err("Failed to remap EFI System Table -- buggy firmware?\n");
+		goto err_unmap;
+	}
+	set_bit(EFI_SYSTEM_TABLES, &efi.flags);
+
+	local_irq_save(flags);
+	cpu_switch_mm(idmap_pg_dir, &init_mm);
+
+	/* Call SetVirtualAddressMap with the physical address of the map */
+	runtime = efi.systab->runtime;
+	efi.set_virtual_address_map = runtime->set_virtual_address_map;
+
+	status = efi.set_virtual_address_map(count * memmap.desc_size,
+					     memmap.desc_size,
+					     memmap.desc_version,
+					     (efi_memory_desc_t *)virtmap_phys);
+	cpu_set_reserved_ttbr0();
+	flush_tlb_all();
+	local_irq_restore(flags);
+
+	kfree(virtmap);
+
+	free_boot_services();
+
+	if (status != EFI_SUCCESS) {
+		pr_err("Failed to set EFI virtual address map! [%lx]\n",
+			status);
+		return -1;
+	}
+
+	/* Set up runtime services function pointers */
+	runtime = efi.systab->runtime;
+	efi_native_runtime_setup();
+	set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+
+	efi.runtime_version = efi.systab->hdr.revision;
+
+	return 0;
+
+err_unmap:
+	/* unmap all mappings that succeeded: there are 'count' of those */
+	for (virt_md = virtmap; count--; virt_md += memmap.desc_size) {
+		md = virt_md;
+		iounmap((__force void __iomem *)md->virt_addr);
+	}
+	kfree(virtmap);
+	return -1;
+}
+early_initcall(arm64_enter_virtual_mode);

arch/arm64/kernel/entry-fpsimd.S

@@ -0,0 +1,67 @@
+/*
+ * FP/SIMD state saving and restoring
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Catalin Marinas <catalin.marinas@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/assembler.h>
+#include <asm/fpsimdmacros.h>
+
+/*
+ * Save the FP registers.
+ *
+ * x0 - pointer to struct fpsimd_state
+ */
+ENTRY(fpsimd_save_state)
+	fpsimd_save x0, 8
+	ret
+ENDPROC(fpsimd_save_state)
+
+/*
+ * Load the FP registers.
+ *
+ * x0 - pointer to struct fpsimd_state
+ */
+ENTRY(fpsimd_load_state)
+	fpsimd_restore x0, 8
+	ret
+ENDPROC(fpsimd_load_state)
+
+#ifdef CONFIG_KERNEL_MODE_NEON
+
+/*
+ * Save the bottom n FP registers.
+ *
+ * x0 - pointer to struct fpsimd_partial_state
+ */
+ENTRY(fpsimd_save_partial_state)
+	fpsimd_save_partial x0, 1, 8, 9
+	ret
+ENDPROC(fpsimd_save_partial_state)
+
+/*
+ * Load the bottom n FP registers.
+ *
+ * x0 - pointer to struct fpsimd_partial_state
+ */
+ENTRY(fpsimd_load_partial_state)
+	fpsimd_restore_partial x0, 8, 9
+	ret
+ENDPROC(fpsimd_load_partial_state)
+
+#endif

arch/arm64/kernel/entry-ftrace.S

@@ -0,0 +1,213 @@
+/*
+ * arch/arm64/kernel/entry-ftrace.S
+ *
+ * Copyright (C) 2013 Linaro Limited
+ * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+#include <asm/ftrace.h>
+#include <asm/insn.h>
+
+/*
+ * Gcc with -pg will put the following code in the beginning of each function:
+ *      mov x0, x30
+ *      bl _mcount
+ *	[function's body ...]
+ * "bl _mcount" may be replaced to "bl ftrace_caller" or NOP if dynamic
+ * ftrace is enabled.
+ *
+ * Please note that x0 as an argument will not be used here because we can
+ * get lr(x30) of instrumented function at any time by winding up call stack
+ * as long as the kernel is compiled without -fomit-frame-pointer.
+ * (or CONFIG_FRAME_POINTER, this is forced on arm64)
+ *
+ * stack layout after mcount_enter in _mcount():
+ *
+ * current sp/fp =>  0:+-----+
+ * in _mcount()        | x29 | -> instrumented function's fp
+ *                     +-----+
+ *                     | x30 | -> _mcount()'s lr (= instrumented function's pc)
+ * old sp       => +16:+-----+
+ * when instrumented   |     |
+ * function calls      | ... |
+ * _mcount()           |     |
+ *                     |     |
+ * instrumented => +xx:+-----+
+ * function's fp       | x29 | -> parent's fp
+ *                     +-----+
+ *                     | x30 | -> instrumented function's lr (= parent's pc)
+ *                     +-----+
+ *                     | ... |
+ */
+
+	.macro mcount_enter
+	stp	x29, x30, [sp, #-16]!
+	mov	x29, sp
+	.endm
+
+	.macro mcount_exit
+	ldp	x29, x30, [sp], #16
+	ret
+	.endm
+
+	.macro mcount_adjust_addr rd, rn
+	sub	\rd, \rn, #AARCH64_INSN_SIZE
+	.endm
+
+	/* for instrumented function's parent */
+	.macro mcount_get_parent_fp reg
+	ldr	\reg, [x29]
+	ldr	\reg, [\reg]
+	.endm
+
+	/* for instrumented function */
+	.macro mcount_get_pc0 reg
+	mcount_adjust_addr	\reg, x30
+	.endm
+
+	.macro mcount_get_pc reg
+	ldr	\reg, [x29, #8]
+	mcount_adjust_addr	\reg, \reg
+	.endm
+
+	.macro mcount_get_lr reg
+	ldr	\reg, [x29]
+	ldr	\reg, [\reg, #8]
+	mcount_adjust_addr	\reg, \reg
+	.endm
+
+	.macro mcount_get_lr_addr reg
+	ldr	\reg, [x29]
+	add	\reg, \reg, #8
+	.endm
+
+#ifndef CONFIG_DYNAMIC_FTRACE
+/*
+ * void _mcount(unsigned long return_address)
+ * @return_address: return address to instrumented function
+ *
+ * This function makes calls, if enabled, to:
+ *     - tracer function to probe instrumented function's entry,
+ *     - ftrace_graph_caller to set up an exit hook
+ */
+ENTRY(_mcount)
+	mcount_enter
+
+	ldr	x0, =ftrace_trace_function
+	ldr	x2, [x0]
+	adr	x0, ftrace_stub
+	cmp	x0, x2			// if (ftrace_trace_function
+	b.eq	skip_ftrace_call	//     != ftrace_stub) {
+
+	mcount_get_pc	x0		//       function's pc
+	mcount_get_lr	x1		//       function's lr (= parent's pc)
+	blr	x2			//   (*ftrace_trace_function)(pc, lr);
+
+#ifndef CONFIG_FUNCTION_GRAPH_TRACER
+skip_ftrace_call:			//   return;
+	mcount_exit			// }
+#else
+	mcount_exit			//   return;
+					// }
+skip_ftrace_call:
+	ldr	x1, =ftrace_graph_return
+	ldr	x2, [x1]		//   if ((ftrace_graph_return
+	cmp	x0, x2			//        != ftrace_stub)
+	b.ne	ftrace_graph_caller
+
+	ldr	x1, =ftrace_graph_entry	//     || (ftrace_graph_entry
+	ldr	x2, [x1]		//        != ftrace_graph_entry_stub))
+	ldr	x0, =ftrace_graph_entry_stub
+	cmp	x0, x2
+	b.ne	ftrace_graph_caller	//     ftrace_graph_caller();
+
+	mcount_exit
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+ENDPROC(_mcount)
+
+#else /* CONFIG_DYNAMIC_FTRACE */
+/*
+ * _mcount() is used to build the kernel with -pg option, but all the branch
+ * instructions to _mcount() are replaced to NOP initially at kernel start up,
+ * and later on, NOP to branch to ftrace_caller() when enabled or branch to
+ * NOP when disabled per-function base.
+ */
+ENTRY(_mcount)
+	ret
+ENDPROC(_mcount)
+
+/*
+ * void ftrace_caller(unsigned long return_address)
+ * @return_address: return address to instrumented function
+ *
+ * This function is a counterpart of _mcount() in 'static' ftrace, and
+ * makes calls to:
+ *     - tracer function to probe instrumented function's entry,
+ *     - ftrace_graph_caller to set up an exit hook
+ */
+ENTRY(ftrace_caller)
+	mcount_enter
+
+	mcount_get_pc0	x0		//     function's pc
+	mcount_get_lr	x1		//     function's lr
+
+	.global ftrace_call
+ftrace_call:				// tracer(pc, lr);
+	nop				// This will be replaced with "bl xxx"
+					// where xxx can be any kind of tracer.
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	.global ftrace_graph_call
+ftrace_graph_call:			// ftrace_graph_caller();
+	nop				// If enabled, this will be replaced
+					// "b ftrace_graph_caller"
+#endif
+
+	mcount_exit
+ENDPROC(ftrace_caller)
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+ENTRY(ftrace_stub)
+	ret
+ENDPROC(ftrace_stub)
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+/*
+ * void ftrace_graph_caller(void)
+ *
+ * Called from _mcount() or ftrace_caller() when function_graph tracer is
+ * selected.
+ * This function w/ prepare_ftrace_return() fakes link register's value on
+ * the call stack in order to intercept instrumented function's return path
+ * and run return_to_handler() later on its exit.
+ */
+ENTRY(ftrace_graph_caller)
+	mcount_get_lr_addr	  x0	//     pointer to function's saved lr
+	mcount_get_pc		  x1	//     function's pc
+	mcount_get_parent_fp	  x2	//     parent's fp
+	bl	prepare_ftrace_return	// prepare_ftrace_return(&lr, pc, fp)
+
+	mcount_exit
+ENDPROC(ftrace_graph_caller)
+
+/*
+ * void return_to_handler(void)
+ *
+ * Run ftrace_return_to_handler() before going back to parent.
+ * @fp is checked against the value passed by ftrace_graph_caller()
+ * only when CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST is enabled.
+ */
+ENTRY(return_to_handler)
+	str	x0, [sp, #-16]!
+	mov	x0, x29			//     parent's fp
+	bl	ftrace_return_to_handler// addr = ftrace_return_to_hander(fp);
+	mov	x30, x0			// restore the original return address
+	ldr	x0, [sp], #16
+	ret
+END(return_to_handler)
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

arch/arm64/kernel/entry.S

@@ -0,0 +1,731 @@
+/*
+ * Low-level exception handling code
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Authors:	Catalin Marinas <catalin.marinas@arm.com>
+ *		Will Deacon <will.deacon@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+
+#include <asm/alternative-asm.h>
+#include <asm/assembler.h>
+#include <asm/asm-offsets.h>
+#include <asm/cpufeature.h>
+#include <asm/errno.h>
+#include <asm/esr.h>
+#include <asm/thread_info.h>
+#include <asm/unistd.h>
+
+/*
+ * Context tracking subsystem.  Used to instrument transitions
+ * between user and kernel mode.
+ */
+	.macro ct_user_exit, syscall = 0
+#ifdef CONFIG_CONTEXT_TRACKING
+	bl	context_tracking_user_exit
+	.if \syscall == 1
+	/*
+	 * Save/restore needed during syscalls.  Restore syscall arguments from
+	 * the values already saved on stack during kernel_entry.
+	 */
+	ldp	x0, x1, [sp]
+	ldp	x2, x3, [sp, #S_X2]
+	ldp	x4, x5, [sp, #S_X4]
+	ldp	x6, x7, [sp, #S_X6]
+	.endif
+#endif
+	.endm
+
+	.macro ct_user_enter
+#ifdef CONFIG_CONTEXT_TRACKING
+	bl	context_tracking_user_enter
+#endif
+	.endm
+
+/*
+ * Bad Abort numbers
+ *-----------------
+ */
+#define BAD_SYNC	0
+#define BAD_IRQ		1
+#define BAD_FIQ		2
+#define BAD_ERROR	3
+
+	.macro	kernel_entry, el, regsize = 64
+	sub	sp, sp, #S_FRAME_SIZE - S_LR	// room for LR, SP, SPSR, ELR
+	.if	\regsize == 32
+	mov	w0, w0				// zero upper 32 bits of x0
+	.endif
+	push	x28, x29
+	push	x26, x27
+	push	x24, x25
+	push	x22, x23
+	push	x20, x21
+	push	x18, x19
+	push	x16, x17
+	push	x14, x15
+	push	x12, x13
+	push	x10, x11
+	push	x8, x9
+	push	x6, x7
+	push	x4, x5
+	push	x2, x3
+	push	x0, x1
+	.if	\el == 0
+	mrs	x21, sp_el0
+	get_thread_info tsk			// Ensure MDSCR_EL1.SS is clear,
+	ldr	x19, [tsk, #TI_FLAGS]		// since we can unmask debug
+	disable_step_tsk x19, x20		// exceptions when scheduling.
+	.else
+	add	x21, sp, #S_FRAME_SIZE
+	.endif
+	mrs	x22, elr_el1
+	mrs	x23, spsr_el1
+	stp	lr, x21, [sp, #S_LR]
+	stp	x22, x23, [sp, #S_PC]
+
+	/*
+	 * Set syscallno to -1 by default (overridden later if real syscall).
+	 */
+	.if	\el == 0
+	mvn	x21, xzr
+	str	x21, [sp, #S_SYSCALLNO]
+	.endif
+
+	/*
+	 * Registers that may be useful after this macro is invoked:
+	 *
+	 * x21 - aborted SP
+	 * x22 - aborted PC
+	 * x23 - aborted PSTATE
+	*/
+	.endm
+
+	.macro	kernel_exit, el, ret = 0
+	ldp	x21, x22, [sp, #S_PC]		// load ELR, SPSR
+	.if	\el == 0
+	ct_user_enter
+	ldr	x23, [sp, #S_SP]		// load return stack pointer
+
+#ifdef CONFIG_ARM64_ERRATUM_845719
+	alternative_insn						\
+	"nop",								\
+	"tbz x22, #4, 1f",						\
+	ARM64_WORKAROUND_845719
+#ifdef CONFIG_PID_IN_CONTEXTIDR
+	alternative_insn						\
+	"nop; nop",							\
+	"mrs x29, contextidr_el1; msr contextidr_el1, x29; 1:",		\
+	ARM64_WORKAROUND_845719
+#else
+	alternative_insn						\
+	"nop",								\
+	"msr contextidr_el1, xzr; 1:",					\
+	ARM64_WORKAROUND_845719
+#endif
+#endif
+	.endif
+	.if	\ret
+	ldr	x1, [sp, #S_X1]			// preserve x0 (syscall return)
+	add	sp, sp, S_X2
+	.else
+	pop	x0, x1
+	.endif
+	pop	x2, x3				// load the rest of the registers
+	pop	x4, x5
+	pop	x6, x7
+	pop	x8, x9
+	msr	elr_el1, x21			// set up the return data
+	msr	spsr_el1, x22
+	.if	\el == 0
+	msr	sp_el0, x23
+	.endif
+	pop	x10, x11
+	pop	x12, x13
+	pop	x14, x15
+	pop	x16, x17
+	pop	x18, x19
+	pop	x20, x21
+	pop	x22, x23
+	pop	x24, x25
+	pop	x26, x27
+	pop	x28, x29
+	ldr	lr, [sp], #S_FRAME_SIZE - S_LR	// load LR and restore SP
+	eret					// return to kernel
+	.endm
+
+	.macro	get_thread_info, rd
+	mov	\rd, sp
+	and	\rd, \rd, #~(THREAD_SIZE - 1)	// top of stack
+	.endm
+
+/*
+ * These are the registers used in the syscall handler, and allow us to
+ * have in theory up to 7 arguments to a function - x0 to x6.
+ *
+ * x7 is reserved for the system call number in 32-bit mode.
+ */
+sc_nr	.req	x25		// number of system calls
+scno	.req	x26		// syscall number
+stbl	.req	x27		// syscall table pointer
+tsk	.req	x28		// current thread_info
+
+/*
+ * Interrupt handling.
+ */
+	.macro	irq_handler
+	adrp	x1, handle_arch_irq
+	ldr	x1, [x1, #:lo12:handle_arch_irq]
+	mov	x0, sp
+	blr	x1
+	.endm
+
+	.text
+
+/*
+ * Exception vectors.
+ */
+
+	.align	11
+ENTRY(vectors)
+	ventry	el1_sync_invalid		// Synchronous EL1t
+	ventry	el1_irq_invalid			// IRQ EL1t
+	ventry	el1_fiq_invalid			// FIQ EL1t
+	ventry	el1_error_invalid		// Error EL1t
+
+	ventry	el1_sync			// Synchronous EL1h
+	ventry	el1_irq				// IRQ EL1h
+	ventry	el1_fiq_invalid			// FIQ EL1h
+	ventry	el1_error_invalid		// Error EL1h
+
+	ventry	el0_sync			// Synchronous 64-bit EL0
+	ventry	el0_irq				// IRQ 64-bit EL0
+	ventry	el0_fiq_invalid			// FIQ 64-bit EL0
+	ventry	el0_error_invalid		// Error 64-bit EL0
+
+#ifdef CONFIG_COMPAT
+	ventry	el0_sync_compat			// Synchronous 32-bit EL0
+	ventry	el0_irq_compat			// IRQ 32-bit EL0
+	ventry	el0_fiq_invalid_compat		// FIQ 32-bit EL0
+	ventry	el0_error_invalid_compat	// Error 32-bit EL0
+#else
+	ventry	el0_sync_invalid		// Synchronous 32-bit EL0
+	ventry	el0_irq_invalid			// IRQ 32-bit EL0
+	ventry	el0_fiq_invalid			// FIQ 32-bit EL0
+	ventry	el0_error_invalid		// Error 32-bit EL0
+#endif
+END(vectors)
+
+/*
+ * Invalid mode handlers
+ */
+	.macro	inv_entry, el, reason, regsize = 64
+	kernel_entry el, \regsize
+	mov	x0, sp
+	mov	x1, #\reason
+	mrs	x2, esr_el1
+	b	bad_mode
+	.endm
+
+el0_sync_invalid:
+	inv_entry 0, BAD_SYNC
+ENDPROC(el0_sync_invalid)
+
+el0_irq_invalid:
+	inv_entry 0, BAD_IRQ
+ENDPROC(el0_irq_invalid)
+
+el0_fiq_invalid:
+	inv_entry 0, BAD_FIQ
+ENDPROC(el0_fiq_invalid)
+
+el0_error_invalid:
+	inv_entry 0, BAD_ERROR
+ENDPROC(el0_error_invalid)
+
+#ifdef CONFIG_COMPAT
+el0_fiq_invalid_compat:
+	inv_entry 0, BAD_FIQ, 32
+ENDPROC(el0_fiq_invalid_compat)
+
+el0_error_invalid_compat:
+	inv_entry 0, BAD_ERROR, 32
+ENDPROC(el0_error_invalid_compat)
+#endif
+
+el1_sync_invalid:
+	inv_entry 1, BAD_SYNC
+ENDPROC(el1_sync_invalid)
+
+el1_irq_invalid:
+	inv_entry 1, BAD_IRQ
+ENDPROC(el1_irq_invalid)
+
+el1_fiq_invalid:
+	inv_entry 1, BAD_FIQ
+ENDPROC(el1_fiq_invalid)
+
+el1_error_invalid:
+	inv_entry 1, BAD_ERROR
+ENDPROC(el1_error_invalid)
+
+/*
+ * EL1 mode handlers.
+ */
+	.align	6
+el1_sync:
+	kernel_entry 1
+	mrs	x1, esr_el1			// read the syndrome register
+	lsr	x24, x1, #ESR_EL1_EC_SHIFT	// exception class
+	cmp	x24, #ESR_EL1_EC_DABT_EL1	// data abort in EL1
+	b.eq	el1_da
+	cmp	x24, #ESR_EL1_EC_SYS64		// configurable trap
+	b.eq	el1_undef
+	cmp	x24, #ESR_EL1_EC_SP_ALIGN	// stack alignment exception
+	b.eq	el1_sp_pc
+	cmp	x24, #ESR_EL1_EC_PC_ALIGN	// pc alignment exception
+	b.eq	el1_sp_pc
+	cmp	x24, #ESR_EL1_EC_UNKNOWN	// unknown exception in EL1
+	b.eq	el1_undef
+	cmp	x24, #ESR_EL1_EC_BREAKPT_EL1	// debug exception in EL1
+	b.ge	el1_dbg
+	b	el1_inv
+el1_da:
+	/*
+	 * Data abort handling
+	 */
+	mrs	x0, far_el1
+	enable_dbg
+	// re-enable interrupts if they were enabled in the aborted context
+	tbnz	x23, #7, 1f			// PSR_I_BIT
+	enable_irq
+1:
+	mov	x2, sp				// struct pt_regs
+	bl	do_mem_abort
+
+	// disable interrupts before pulling preserved data off the stack
+	disable_irq
+	kernel_exit 1
+el1_sp_pc:
+	/*
+	 * Stack or PC alignment exception handling
+	 */
+	mrs	x0, far_el1
+	enable_dbg
+	mov	x2, sp
+	b	do_sp_pc_abort
+el1_undef:
+	/*
+	 * Undefined instruction
+	 */
+	enable_dbg
+	mov	x0, sp
+	b	do_undefinstr
+el1_dbg:
+	/*
+	 * Debug exception handling
+	 */
+	cmp	x24, #ESR_EL1_EC_BRK64		// if BRK64
+	cinc	x24, x24, eq			// set bit '0'
+	tbz	x24, #0, el1_inv		// EL1 only
+	mrs	x0, far_el1
+	mov	x2, sp				// struct pt_regs
+	bl	do_debug_exception
+	kernel_exit 1
+el1_inv:
+	// TODO: add support for undefined instructions in kernel mode
+	enable_dbg
+	mov	x0, sp
+	mov	x1, #BAD_SYNC
+	mrs	x2, esr_el1
+	b	bad_mode
+ENDPROC(el1_sync)
+
+	.align	6
+el1_irq:
+	kernel_entry 1
+	enable_dbg
+#ifdef CONFIG_TRACE_IRQFLAGS
+	bl	trace_hardirqs_off
+#endif
+
+	irq_handler
+
+#ifdef CONFIG_PREEMPT
+	get_thread_info tsk
+	ldr	w24, [tsk, #TI_PREEMPT]		// get preempt count
+	cbnz	w24, 1f				// preempt count != 0
+	ldr	x0, [tsk, #TI_FLAGS]		// get flags
+	tbz	x0, #TIF_NEED_RESCHED, 1f	// needs rescheduling?
+	bl	el1_preempt
+1:
+#endif
+#ifdef CONFIG_TRACE_IRQFLAGS
+	bl	trace_hardirqs_on
+#endif
+	kernel_exit 1
+ENDPROC(el1_irq)
+
+#ifdef CONFIG_PREEMPT
+el1_preempt:
+	mov	x24, lr
+1:	bl	preempt_schedule_irq		// irq en/disable is done inside
+	ldr	x0, [tsk, #TI_FLAGS]		// get new tasks TI_FLAGS
+	tbnz	x0, #TIF_NEED_RESCHED, 1b	// needs rescheduling?
+	ret	x24
+#endif
+
+/*
+ * EL0 mode handlers.
+ */
+	.align	6
+el0_sync:
+	kernel_entry 0
+	mrs	x25, esr_el1			// read the syndrome register
+	lsr	x24, x25, #ESR_EL1_EC_SHIFT	// exception class
+	cmp	x24, #ESR_EL1_EC_SVC64		// SVC in 64-bit state
+	b.eq	el0_svc
+	cmp	x24, #ESR_EL1_EC_DABT_EL0	// data abort in EL0
+	b.eq	el0_da
+	cmp	x24, #ESR_EL1_EC_IABT_EL0	// instruction abort in EL0
+	b.eq	el0_ia
+	cmp	x24, #ESR_EL1_EC_FP_ASIMD	// FP/ASIMD access
+	b.eq	el0_fpsimd_acc
+	cmp	x24, #ESR_EL1_EC_FP_EXC64	// FP/ASIMD exception
+	b.eq	el0_fpsimd_exc
+	cmp	x24, #ESR_EL1_EC_SYS64		// configurable trap
+	b.eq	el0_undef
+	cmp	x24, #ESR_EL1_EC_SP_ALIGN	// stack alignment exception
+	b.eq	el0_sp_pc
+	cmp	x24, #ESR_EL1_EC_PC_ALIGN	// pc alignment exception
+	b.eq	el0_sp_pc
+	cmp	x24, #ESR_EL1_EC_UNKNOWN	// unknown exception in EL0
+	b.eq	el0_undef
+	cmp	x24, #ESR_EL1_EC_BREAKPT_EL0	// debug exception in EL0
+	b.ge	el0_dbg
+	b	el0_inv
+
+#ifdef CONFIG_COMPAT
+	.align	6
+el0_sync_compat:
+	kernel_entry 0, 32
+	mrs	x25, esr_el1			// read the syndrome register
+	lsr	x24, x25, #ESR_EL1_EC_SHIFT	// exception class
+	cmp	x24, #ESR_EL1_EC_SVC32		// SVC in 32-bit state
+	b.eq	el0_svc_compat
+	cmp	x24, #ESR_EL1_EC_DABT_EL0	// data abort in EL0
+	b.eq	el0_da
+	cmp	x24, #ESR_EL1_EC_IABT_EL0	// instruction abort in EL0
+	b.eq	el0_ia
+	cmp	x24, #ESR_EL1_EC_FP_ASIMD	// FP/ASIMD access
+	b.eq	el0_fpsimd_acc
+	cmp	x24, #ESR_EL1_EC_FP_EXC32	// FP/ASIMD exception
+	b.eq	el0_fpsimd_exc
+	cmp	x24, #ESR_EL1_EC_UNKNOWN	// unknown exception in EL0
+	b.eq	el0_undef
+	cmp	x24, #ESR_EL1_EC_CP15_32	// CP15 MRC/MCR trap
+	b.eq	el0_undef
+	cmp	x24, #ESR_EL1_EC_CP15_64	// CP15 MRRC/MCRR trap
+	b.eq	el0_undef
+	cmp	x24, #ESR_EL1_EC_CP14_MR	// CP14 MRC/MCR trap
+	b.eq	el0_undef
+	cmp	x24, #ESR_EL1_EC_CP14_LS	// CP14 LDC/STC trap
+	b.eq	el0_undef
+	cmp	x24, #ESR_EL1_EC_CP14_64	// CP14 MRRC/MCRR trap
+	b.eq	el0_undef
+	cmp	x24, #ESR_EL1_EC_BREAKPT_EL0	// debug exception in EL0
+	b.ge	el0_dbg
+	b	el0_inv
+el0_svc_compat:
+	/*
+	 * AArch32 syscall handling
+	 */
+	adr	stbl, compat_sys_call_table	// load compat syscall table pointer
+	uxtw	scno, w7			// syscall number in w7 (r7)
+	mov     sc_nr, #__NR_compat_syscalls
+	b	el0_svc_naked
+
+	.align	6
+el0_irq_compat:
+	kernel_entry 0, 32
+	b	el0_irq_naked
+#endif
+
+el0_da:
+	/*
+	 * Data abort handling
+	 */
+	mrs	x26, far_el1
+	// enable interrupts before calling the main handler
+	enable_dbg_and_irq
+	ct_user_exit
+	bic	x0, x26, #(0xff << 56)
+	mov	x1, x25
+	mov	x2, sp
+	bl	do_mem_abort
+	b	ret_to_user
+el0_ia:
+	/*
+	 * Instruction abort handling
+	 */
+	mrs	x26, far_el1
+	// enable interrupts before calling the main handler
+	enable_dbg_and_irq
+	ct_user_exit
+	mov	x0, x26
+	orr	x1, x25, #1 << 24		// use reserved ISS bit for instruction aborts
+	mov	x2, sp
+	bl	do_mem_abort
+	b	ret_to_user
+el0_fpsimd_acc:
+	/*
+	 * Floating Point or Advanced SIMD access
+	 */
+	enable_dbg
+	ct_user_exit
+	mov	x0, x25
+	mov	x1, sp
+	bl	do_fpsimd_acc
+	b	ret_to_user
+el0_fpsimd_exc:
+	/*
+	 * Floating Point or Advanced SIMD exception
+	 */
+	enable_dbg
+	ct_user_exit
+	mov	x0, x25
+	mov	x1, sp
+	bl	do_fpsimd_exc
+	b	ret_to_user
+el0_sp_pc:
+	/*
+	 * Stack or PC alignment exception handling
+	 */
+	mrs	x26, far_el1
+	// enable interrupts before calling the main handler
+	enable_dbg_and_irq
+	mov	x0, x26
+	mov	x1, x25
+	mov	x2, sp
+	bl	do_sp_pc_abort
+	b	ret_to_user
+el0_undef:
+	/*
+	 * Undefined instruction
+	 */
+	// enable interrupts before calling the main handler
+	enable_dbg_and_irq
+	ct_user_exit
+	mov	x0, sp
+	bl	do_undefinstr
+	b	ret_to_user
+el0_dbg:
+	/*
+	 * Debug exception handling
+	 */
+	tbnz	x24, #0, el0_inv		// EL0 only
+	mrs	x0, far_el1
+	mov	x1, x25
+	mov	x2, sp
+	bl	do_debug_exception
+	enable_dbg
+	ct_user_exit
+	b	ret_to_user
+el0_inv:
+	enable_dbg
+	ct_user_exit
+	mov	x0, sp
+	mov	x1, #BAD_SYNC
+	mrs	x2, esr_el1
+	bl	bad_mode
+	b	ret_to_user
+ENDPROC(el0_sync)
+
+	.align	6
+el0_irq:
+	kernel_entry 0
+el0_irq_naked:
+	enable_dbg
+#ifdef CONFIG_TRACE_IRQFLAGS
+	bl	trace_hardirqs_off
+#endif
+
+	ct_user_exit
+	irq_handler
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+	bl	trace_hardirqs_on
+#endif
+	b	ret_to_user
+ENDPROC(el0_irq)
+
+/*
+ * Register switch for AArch64. The callee-saved registers need to be saved
+ * and restored. On entry:
+ *   x0 = previous task_struct (must be preserved across the switch)
+ *   x1 = next task_struct
+ * Previous and next are guaranteed not to be the same.
+ *
+ */
+ENTRY(cpu_switch_to)
+	add	x8, x0, #THREAD_CPU_CONTEXT
+	mov	x9, sp
+	stp	x19, x20, [x8], #16		// store callee-saved registers
+	stp	x21, x22, [x8], #16
+	stp	x23, x24, [x8], #16
+	stp	x25, x26, [x8], #16
+	stp	x27, x28, [x8], #16
+	stp	x29, x9, [x8], #16
+	str	lr, [x8]
+	add	x8, x1, #THREAD_CPU_CONTEXT
+	ldp	x19, x20, [x8], #16		// restore callee-saved registers
+	ldp	x21, x22, [x8], #16
+	ldp	x23, x24, [x8], #16
+	ldp	x25, x26, [x8], #16
+	ldp	x27, x28, [x8], #16
+	ldp	x29, x9, [x8], #16
+	ldr	lr, [x8]
+	mov	sp, x9
+	ret
+ENDPROC(cpu_switch_to)
+
+/*
+ * This is the fast syscall return path.  We do as little as possible here,
+ * and this includes saving x0 back into the kernel stack.
+ */
+ret_fast_syscall:
+	disable_irq				// disable interrupts
+	ldr	x1, [tsk, #TI_FLAGS]
+	and	x2, x1, #_TIF_WORK_MASK
+	cbnz	x2, fast_work_pending
+	enable_step_tsk x1, x2
+	kernel_exit 0, ret = 1
+
+/*
+ * Ok, we need to do extra processing, enter the slow path.
+ */
+fast_work_pending:
+	str	x0, [sp, #S_X0]			// returned x0
+work_pending:
+	tbnz	x1, #TIF_NEED_RESCHED, work_resched
+	/* TIF_SIGPENDING, TIF_NOTIFY_RESUME or TIF_FOREIGN_FPSTATE case */
+	ldr	x2, [sp, #S_PSTATE]
+	mov	x0, sp				// 'regs'
+	tst	x2, #PSR_MODE_MASK		// user mode regs?
+	b.ne	no_work_pending			// returning to kernel
+	enable_irq				// enable interrupts for do_notify_resume()
+	bl	do_notify_resume
+	b	ret_to_user
+work_resched:
+	bl	schedule
+
+/*
+ * "slow" syscall return path.
+ */
+ret_to_user:
+	disable_irq				// disable interrupts
+	ldr	x1, [tsk, #TI_FLAGS]
+	and	x2, x1, #_TIF_WORK_MASK
+	cbnz	x2, work_pending
+	enable_step_tsk x1, x2
+no_work_pending:
+	kernel_exit 0, ret = 0
+ENDPROC(ret_to_user)
+
+/*
+ * This is how we return from a fork.
+ */
+ENTRY(ret_from_fork)
+	bl	schedule_tail
+	cbz	x19, 1f				// not a kernel thread
+	mov	x0, x20
+	blr	x19
+1:	get_thread_info tsk
+	b	ret_to_user
+ENDPROC(ret_from_fork)
+
+/*
+ * SVC handler.
+ */
+	.align	6
+el0_svc:
+	adrp	stbl, sys_call_table		// load syscall table pointer
+	uxtw	scno, w8			// syscall number in w8
+	mov	sc_nr, #__NR_syscalls
+el0_svc_naked:					// compat entry point
+	stp	x0, scno, [sp, #S_ORIG_X0]	// save the original x0 and syscall number
+	enable_dbg_and_irq
+	ct_user_exit 1
+
+	ldr	x16, [tsk, #TI_FLAGS]		// check for syscall hooks
+	tst	x16, #_TIF_SYSCALL_WORK
+	b.ne	__sys_trace
+	cmp     scno, sc_nr                     // check upper syscall limit
+	b.hs	ni_sys
+	ldr	x16, [stbl, scno, lsl #3]	// address in the syscall table
+	blr	x16				// call sys_* routine
+	b	ret_fast_syscall
+ni_sys:
+	mov	x0, sp
+	bl	do_ni_syscall
+	b	ret_fast_syscall
+ENDPROC(el0_svc)
+
+	/*
+	 * This is the really slow path.  We're going to be doing context
+	 * switches, and waiting for our parent to respond.
+	 */
+__sys_trace:
+	mov	w0, #-1				// set default errno for
+	cmp     scno, x0			// user-issued syscall(-1)
+	b.ne	1f
+	mov	x0, #-ENOSYS
+	str	x0, [sp, #S_X0]
+1:	mov	x0, sp
+	bl	syscall_trace_enter
+	cmp	w0, #-1				// skip the syscall?
+	b.eq	__sys_trace_return_skipped
+	uxtw	scno, w0			// syscall number (possibly new)
+	mov	x1, sp				// pointer to regs
+	cmp	scno, sc_nr			// check upper syscall limit
+	b.hs	__ni_sys_trace
+	ldp	x0, x1, [sp]			// restore the syscall args
+	ldp	x2, x3, [sp, #S_X2]
+	ldp	x4, x5, [sp, #S_X4]
+	ldp	x6, x7, [sp, #S_X6]
+	ldr	x16, [stbl, scno, lsl #3]	// address in the syscall table
+	blr	x16				// call sys_* routine
+
+__sys_trace_return:
+	str	x0, [sp, #S_X0]			// save returned x0
+__sys_trace_return_skipped:
+	mov	x0, sp
+	bl	syscall_trace_exit
+	b	ret_to_user
+
+__ni_sys_trace:
+	mov	x0, sp
+	bl	do_ni_syscall
+	b	__sys_trace_return
+
+/*
+ * Special system call wrappers.
+ */
+ENTRY(sys_rt_sigreturn_wrapper)
+	mov	x0, sp
+	b	sys_rt_sigreturn
+ENDPROC(sys_rt_sigreturn_wrapper)

arch/arm64/kernel/exynos-smc.S

@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2014 Samsung Electronics.
+ *
+ * For Secure Monitor Call(SMC)
+ *
+ * This program is free software,you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+
+#include <linux/smc.h>
+
+#include <asm/assembler.h>
+
+#define ESS_FLAG_IN	(1)
+#define ESS_FLAG_OUT	(3)
+
+/*
+ * Function signature:
+ * int exynos_smc(unsigned long cmd, unsigned long arg1, unsigned long arg2, unsigned long arg3)
+ * int exynos_smc_readsfr(unsigned long addr, unsigned long* val)
+ */
+
+ENTRY(__exynos_smc)
+#ifdef CONFIG_EXYNOS_SNAPSHOT_LOGGING_SMC_CALL
+	stp	x29, x30, [sp, #-48]!
+	mov	x29, sp
+	stp	x0, x1, [sp, #16]
+	stp	x2, x3, [sp, #32]
+	ldr	x3, =save_smc_id
+	str	x0, [x3]
+	mov	x3, #ESS_FLAG_IN
+	bl	exynos_ss_irq
+	ldp	x0, x1, [sp, #16]
+	ldp	x2, x3, [sp, #32]
+#endif
+	dsb	sy
+	smc	#0
+#ifdef CONFIG_EXYNOS_SNAPSHOT_LOGGING_SMC_CALL
+	stp	x0, x1, [sp, #16]
+	stp	x2, x3, [sp, #32]
+	ldr	x3, =save_smc_id
+	ldr	x0, [x3]
+	mov	x3, #ESS_FLAG_OUT
+	bl	exynos_ss_irq
+	ldp	x0, x1, [sp, #16]
+	ldp	x2, x3, [sp, #32]
+	ldp	x29, x30, [sp], #48
+#endif
+	ret
+
+	.section .bss
+	.align	3
+save_smc_id:
+	.quad	0x0
+	.previous
+
+ENDPROC(__exynos_smc)
+
+ENTRY(exynos_smc_readsfr)
+	stp	x1, x3, [sp, #-16]!
+
+	/* Currently, the addresses of SFR are 32bit */
+	lsr	w1, w0, #2
+	orr	w1, w1, #SMC_REG_CLASS_SFR_R
+	mov	w0, #SMC_CMD_REG
+	dsb	sy
+	smc	#0
+	ldp	x1, x3, [sp], #16
+	cmp	x0, #0
+	b.ne	fail_read
+
+	str	x2, [x1]
+fail_read:
+	ret
+ENDPROC(exynos_smc_readsfr)

arch/arm64/kernel/fpsimd.c

@@ -0,0 +1,333 @@
+/*
+ * FP/SIMD context switching and fault handling
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Catalin Marinas <catalin.marinas@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/cpu.h>
+#include <linux/cpu_pm.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <linux/hardirq.h>
+
+#include <asm/fpsimd.h>
+#include <asm/cputype.h>
+
+#define FPEXC_IOF	(1 << 0)
+#define FPEXC_DZF	(1 << 1)
+#define FPEXC_OFF	(1 << 2)
+#define FPEXC_UFF	(1 << 3)
+#define FPEXC_IXF	(1 << 4)
+#define FPEXC_IDF	(1 << 7)
+
+/*
+ * In order to reduce the number of times the FPSIMD state is needlessly saved
+ * and restored, we need to keep track of two things:
+ * (a) for each task, we need to remember which CPU was the last one to have
+ *     the task's FPSIMD state loaded into its FPSIMD registers;
+ * (b) for each CPU, we need to remember which task's userland FPSIMD state has
+ *     been loaded into its FPSIMD registers most recently, or whether it has
+ *     been used to perform kernel mode NEON in the meantime.
+ *
+ * For (a), we add a 'cpu' field to struct fpsimd_state, which gets updated to
+ * the id of the current CPU everytime the state is loaded onto a CPU. For (b),
+ * we add the per-cpu variable 'fpsimd_last_state' (below), which contains the
+ * address of the userland FPSIMD state of the task that was loaded onto the CPU
+ * the most recently, or NULL if kernel mode NEON has been performed after that.
+ *
+ * With this in place, we no longer have to restore the next FPSIMD state right
+ * when switching between tasks. Instead, we can defer this check to userland
+ * resume, at which time we verify whether the CPU's fpsimd_last_state and the
+ * task's fpsimd_state.cpu are still mutually in sync. If this is the case, we
+ * can omit the FPSIMD restore.
+ *
+ * As an optimization, we use the thread_info flag TIF_FOREIGN_FPSTATE to
+ * indicate whether or not the userland FPSIMD state of the current task is
+ * present in the registers. The flag is set unless the FPSIMD registers of this
+ * CPU currently contain the most recent userland FPSIMD state of the current
+ * task.
+ *
+ * For a certain task, the sequence may look something like this:
+ * - the task gets scheduled in; if both the task's fpsimd_state.cpu field
+ *   contains the id of the current CPU, and the CPU's fpsimd_last_state per-cpu
+ *   variable points to the task's fpsimd_state, the TIF_FOREIGN_FPSTATE flag is
+ *   cleared, otherwise it is set;
+ *
+ * - the task returns to userland; if TIF_FOREIGN_FPSTATE is set, the task's
+ *   userland FPSIMD state is copied from memory to the registers, the task's
+ *   fpsimd_state.cpu field is set to the id of the current CPU, the current
+ *   CPU's fpsimd_last_state pointer is set to this task's fpsimd_state and the
+ *   TIF_FOREIGN_FPSTATE flag is cleared;
+ *
+ * - the task executes an ordinary syscall; upon return to userland, the
+ *   TIF_FOREIGN_FPSTATE flag will still be cleared, so no FPSIMD state is
+ *   restored;
+ *
+ * - the task executes a syscall which executes some NEON instructions; this is
+ *   preceded by a call to kernel_neon_begin(), which copies the task's FPSIMD
+ *   register contents to memory, clears the fpsimd_last_state per-cpu variable
+ *   and sets the TIF_FOREIGN_FPSTATE flag;
+ *
+ * - the task gets preempted after kernel_neon_end() is called; as we have not
+ *   returned from the 2nd syscall yet, TIF_FOREIGN_FPSTATE is still set so
+ *   whatever is in the FPSIMD registers is not saved to memory, but discarded.
+ */
+static DEFINE_PER_CPU(struct fpsimd_state *, fpsimd_last_state);
+
+/*
+ * Trapped FP/ASIMD access.
+ */
+void do_fpsimd_acc(unsigned int esr, struct pt_regs *regs)
+{
+	/* TODO: implement lazy context saving/restoring */
+	WARN_ON(1);
+}
+
+/*
+ * Raise a SIGFPE for the current process.
+ */
+void do_fpsimd_exc(unsigned int esr, struct pt_regs *regs)
+{
+	siginfo_t info;
+	unsigned int si_code = 0;
+
+	if (esr & FPEXC_IOF)
+		si_code = FPE_FLTINV;
+	else if (esr & FPEXC_DZF)
+		si_code = FPE_FLTDIV;
+	else if (esr & FPEXC_OFF)
+		si_code = FPE_FLTOVF;
+	else if (esr & FPEXC_UFF)
+		si_code = FPE_FLTUND;
+	else if (esr & FPEXC_IXF)
+		si_code = FPE_FLTRES;
+
+	memset(&info, 0, sizeof(info));
+	info.si_signo = SIGFPE;
+	info.si_code = si_code;
+	info.si_addr = (void __user *)instruction_pointer(regs);
+
+	send_sig_info(SIGFPE, &info, current);
+}
+
+void fpsimd_thread_switch(struct task_struct *next)
+{
+	/*
+	 * Save the current FPSIMD state to memory, but only if whatever is in
+	 * the registers is in fact the most recent userland FPSIMD state of
+	 * 'current'.
+	 */
+	if (current->mm || current->thread.fpsimd_state.using)
+		fpsimd_save_state(&current->thread.fpsimd_state);
+
+	if (next->mm || next->thread.fpsimd_state.using)
+		fpsimd_load_state(&next->thread.fpsimd_state);
+}
+
+void fpsimd_flush_thread(void)
+{
+	memset(&current->thread.fpsimd_state, 0, sizeof(struct fpsimd_state));
+	fpsimd_flush_task_state(current);
+}
+
+/*
+ * Save the userland FPSIMD state of 'current' to memory, but only if the state
+ * currently held in the registers does in fact belong to 'current'
+ */
+void fpsimd_preserve_current_state(void)
+{
+	preempt_disable();
+	fpsimd_save_state(&current->thread.fpsimd_state);
+	preempt_enable();
+}
+
+/*
+ * Load the userland FPSIMD state of 'current' from memory, but only if the
+ * FPSIMD state already held in the registers is /not/ the most recent FPSIMD
+ * state of 'current'
+ */
+void fpsimd_restore_current_state(void)
+{
+	struct fpsimd_state *st = &current->thread.fpsimd_state;
+
+	preempt_disable();
+	fpsimd_load_state(st);
+	this_cpu_write(fpsimd_last_state, st);
+	st->cpu = smp_processor_id();
+	preempt_enable();
+}
+
+/*
+ * Load an updated userland FPSIMD state for 'current' from memory and set the
+ * flag that indicates that the FPSIMD register contents are the most recent
+ * FPSIMD state of 'current'
+ */
+void fpsimd_update_current_state(struct fpsimd_state *state)
+{
+	struct fpsimd_state *st = &current->thread.fpsimd_state;
+
+	preempt_disable();
+	fpsimd_load_state(state);
+	this_cpu_write(fpsimd_last_state, st);
+	st->cpu = smp_processor_id();
+	preempt_enable();
+}
+
+/*
+ * Invalidate live CPU copies of task t's FPSIMD state
+ */
+void fpsimd_flush_task_state(struct task_struct *t)
+{
+	t->thread.fpsimd_state.cpu = NR_CPUS;
+}
+
+void fpsimd_set_as_user(struct task_struct *task)
+{
+	task->thread.fpsimd_state.using = 1;
+}
+
+#ifdef CONFIG_KERNEL_MODE_NEON
+
+static DEFINE_PER_CPU(struct fpsimd_partial_state, hardirq_fpsimdstate);
+static DEFINE_PER_CPU(struct fpsimd_partial_state, softirq_fpsimdstate);
+
+/*
+ * Kernel-side NEON support functions
+ */
+void kernel_neon_begin_partial(u32 num_regs)
+{
+	if (in_interrupt()) {
+		struct fpsimd_partial_state *s = this_cpu_ptr(
+			in_irq() ? &hardirq_fpsimdstate : &softirq_fpsimdstate);
+
+		BUG_ON(num_regs > 32);
+		fpsimd_save_partial_state(s, roundup(num_regs, 2));
+	} else {
+		/*
+		 * Save the userland FPSIMD state if we have one and if we
+		 * haven't done so already. Clear fpsimd_last_state to indicate
+		 * that there is no longer userland FPSIMD state in the
+		 * registers.
+		 */
+		preempt_disable();
+		if (current->mm || current->thread.fpsimd_state.using)
+			fpsimd_save_state(&current->thread.fpsimd_state);
+		this_cpu_write(fpsimd_last_state, NULL);
+	}
+}
+EXPORT_SYMBOL(kernel_neon_begin_partial);
+
+void kernel_neon_end(void)
+{
+	if (in_interrupt()) {
+		struct fpsimd_partial_state *s = this_cpu_ptr(
+			in_irq() ? &hardirq_fpsimdstate : &softirq_fpsimdstate);
+		fpsimd_load_partial_state(s);
+	} else {
+		preempt_enable();
+	}
+}
+EXPORT_SYMBOL(kernel_neon_end);
+
+#endif /* CONFIG_KERNEL_MODE_NEON */
+
+#ifdef CONFIG_CPU_PM
+static int fpsimd_cpu_pm_notifier(struct notifier_block *self,
+				  unsigned long cmd, void *v)
+{
+	switch (cmd) {
+	case CPU_PM_ENTER:
+		if (current->mm || current->thread.fpsimd_state.using)
+			fpsimd_save_state(&current->thread.fpsimd_state);
+		this_cpu_write(fpsimd_last_state, NULL);
+		break;
+	case CPU_PM_EXIT:
+		break;
+	case CPU_PM_ENTER_FAILED:
+	default:
+		return NOTIFY_DONE;
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block fpsimd_cpu_pm_notifier_block = {
+	.notifier_call = fpsimd_cpu_pm_notifier,
+};
+
+static void fpsimd_pm_init(void)
+{
+	cpu_pm_register_notifier(&fpsimd_cpu_pm_notifier_block);
+}
+
+#else
+static inline void fpsimd_pm_init(void) { }
+#endif /* CONFIG_CPU_PM */
+
+#ifdef CONFIG_HOTPLUG_CPU
+static int fpsimd_cpu_hotplug_notifier(struct notifier_block *nfb,
+				       unsigned long action,
+				       void *hcpu)
+{
+	unsigned int cpu = (long)hcpu;
+
+	switch (action) {
+	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
+		per_cpu(fpsimd_last_state, cpu) = NULL;
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block fpsimd_cpu_hotplug_notifier_block = {
+	.notifier_call = fpsimd_cpu_hotplug_notifier,
+};
+
+static inline void fpsimd_hotplug_init(void)
+{
+	register_cpu_notifier(&fpsimd_cpu_hotplug_notifier_block);
+}
+
+#else
+static inline void fpsimd_hotplug_init(void) { }
+#endif
+
+/*
+ * FP/SIMD support code initialisation.
+ */
+static int __init fpsimd_init(void)
+{
+	u64 pfr = read_cpuid(ID_AA64PFR0_EL1);
+
+	if (pfr & (0xf << 16)) {
+		pr_notice("Floating-point is not implemented\n");
+		return 0;
+	}
+	elf_hwcap |= HWCAP_FP;
+
+	if (pfr & (0xf << 20))
+		pr_notice("Advanced SIMD is not implemented\n");
+	else
+		elf_hwcap |= HWCAP_ASIMD;
+
+	fpsimd_pm_init();
+	fpsimd_hotplug_init();
+
+	return 0;
+}
+late_initcall(fpsimd_init);

arch/arm64/kernel/ftrace.c

@@ -0,0 +1,178 @@
+/*
+ * arch/arm64/kernel/ftrace.c
+ *
+ * Copyright (C) 2013 Linaro Limited
+ * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ftrace.h>
+#include <linux/swab.h>
+#include <linux/uaccess.h>
+
+#include <asm/cacheflush.h>
+#include <asm/ftrace.h>
+#include <asm/insn.h>
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+/*
+ * Replace a single instruction, which may be a branch or NOP.
+ * If @validate == true, a replaced instruction is checked against 'old'.
+ */
+static int ftrace_modify_code(unsigned long pc, u32 old, u32 new,
+			      bool validate)
+{
+	u32 replaced;
+
+	/*
+	 * Note:
+	 * Due to modules and __init, code can disappear and change,
+	 * we need to protect against faulting as well as code changing.
+	 * We do this by aarch64_insn_*() which use the probe_kernel_*().
+	 *
+	 * No lock is held here because all the modifications are run
+	 * through stop_machine().
+	 */
+	if (validate) {
+		if (aarch64_insn_read((void *)pc, &replaced))
+			return -EFAULT;
+
+		if (replaced != old)
+			return -EINVAL;
+	}
+	if (aarch64_insn_patch_text_nosync((void *)pc, new))
+		return -EPERM;
+
+	return 0;
+}
+
+/*
+ * Replace tracer function in ftrace_caller()
+ */
+int ftrace_update_ftrace_func(ftrace_func_t func)
+{
+	unsigned long pc;
+	u32 new;
+
+	pc = (unsigned long)&ftrace_call;
+	new = aarch64_insn_gen_branch_imm(pc, (unsigned long)func,
+					  AARCH64_INSN_BRANCH_LINK);
+
+	return ftrace_modify_code(pc, 0, new, false);
+}
+
+/*
+ * Turn on the call to ftrace_caller() in instrumented function
+ */
+int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+	unsigned long pc = rec->ip;
+	u32 old, new;
+
+	old = aarch64_insn_gen_nop();
+	new = aarch64_insn_gen_branch_imm(pc, addr, AARCH64_INSN_BRANCH_LINK);
+
+	return ftrace_modify_code(pc, old, new, true);
+}
+
+/*
+ * Turn off the call to ftrace_caller() in instrumented function
+ */
+int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
+		    unsigned long addr)
+{
+	unsigned long pc = rec->ip;
+	u32 old, new;
+
+	old = aarch64_insn_gen_branch_imm(pc, addr, AARCH64_INSN_BRANCH_LINK);
+	new = aarch64_insn_gen_nop();
+
+	return ftrace_modify_code(pc, old, new, true);
+}
+
+int __init ftrace_dyn_arch_init(void)
+{
+	return 0;
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+/*
+ * function_graph tracer expects ftrace_return_to_handler() to be called
+ * on the way back to parent. For this purpose, this function is called
+ * in _mcount() or ftrace_caller() to replace return address (*parent) on
+ * the call stack to return_to_handler.
+ *
+ * Note that @frame_pointer is used only for sanity check later.
+ */
+void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
+			   unsigned long frame_pointer)
+{
+	unsigned long return_hooker = (unsigned long)&return_to_handler;
+	unsigned long old;
+	struct ftrace_graph_ent trace;
+	int err;
+
+	if (unlikely(atomic_read(&current->tracing_graph_pause)))
+		return;
+
+	/*
+	 * Note:
+	 * No protection against faulting at *parent, which may be seen
+	 * on other archs. It's unlikely on AArch64.
+	 */
+	old = *parent;
+	*parent = return_hooker;
+
+	trace.func = self_addr;
+	trace.depth = current->curr_ret_stack + 1;
+
+	/* Only trace if the calling function expects to */
+	if (!ftrace_graph_entry(&trace)) {
+		*parent = old;
+		return;
+	}
+
+	err = ftrace_push_return_trace(old, self_addr, &trace.depth,
+				       frame_pointer);
+	if (err == -EBUSY) {
+		*parent = old;
+		return;
+	}
+}
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+/*
+ * Turn on/off the call to ftrace_graph_caller() in ftrace_caller()
+ * depending on @enable.
+ */
+static int ftrace_modify_graph_caller(bool enable)
+{
+	unsigned long pc = (unsigned long)&ftrace_graph_call;
+	u32 branch, nop;
+
+	branch = aarch64_insn_gen_branch_imm(pc,
+					     (unsigned long)ftrace_graph_caller,
+					     AARCH64_INSN_BRANCH_LINK);
+	nop = aarch64_insn_gen_nop();
+
+	if (enable)
+		return ftrace_modify_code(pc, nop, branch, true);
+	else
+		return ftrace_modify_code(pc, branch, nop, true);
+}
+
+int ftrace_enable_ftrace_graph_caller(void)
+{
+	return ftrace_modify_graph_caller(true);
+}
+
+int ftrace_disable_ftrace_graph_caller(void)
+{
+	return ftrace_modify_graph_caller(false);
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

arch/arm64/kernel/head.S

@@ -0,0 +1,744 @@
+/*
+ * Low-level CPU initialisation
+ * Based on arch/arm/kernel/head.S
+ *
+ * Copyright (C) 1994-2002 Russell King
+ * Copyright (C) 2003-2012 ARM Ltd.
+ * Authors:	Catalin Marinas <catalin.marinas@arm.com>
+ *		Will Deacon <will.deacon@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <linux/irqchip/arm-gic-v3.h>
+
+#include <asm/assembler.h>
+#include <asm/ptrace.h>
+#include <asm/asm-offsets.h>
+#include <asm/cache.h>
+#include <asm/cputype.h>
+#include <asm/memory.h>
+#include <asm/thread_info.h>
+#include <asm/pgtable-hwdef.h>
+#include <asm/pgtable.h>
+#include <asm/page.h>
+#include <asm/virt.h>
+
+#define KERNEL_RAM_VADDR	(PAGE_OFFSET + TEXT_OFFSET)
+
+#if (TEXT_OFFSET & 0xfff) != 0
+#error TEXT_OFFSET must be at least 4KB aligned
+#elif (PAGE_OFFSET & 0x1fffff) != 0
+#error PAGE_OFFSET must be at least 2MB aligned
+#elif TEXT_OFFSET > 0x1fffff
+#error TEXT_OFFSET must be less than 2MB
+#endif
+
+	.macro	pgtbl, ttb0, ttb1, virt_to_phys
+	ldr	\ttb1, =swapper_pg_dir
+	ldr	\ttb0, =idmap_pg_dir
+	add	\ttb1, \ttb1, \virt_to_phys
+	add	\ttb0, \ttb0, \virt_to_phys
+	.endm
+
+#ifdef CONFIG_ARM64_64K_PAGES
+#define BLOCK_SHIFT	PAGE_SHIFT
+#define BLOCK_SIZE	PAGE_SIZE
+#define TABLE_SHIFT	PMD_SHIFT
+#else
+#define BLOCK_SHIFT	SECTION_SHIFT
+#define BLOCK_SIZE	SECTION_SIZE
+#define TABLE_SHIFT	PUD_SHIFT
+#endif
+
+#define KERNEL_START	KERNEL_RAM_VADDR
+#define KERNEL_END	_end
+
+/*
+ * Initial memory map attributes.
+ */
+#ifndef CONFIG_SMP
+#define PTE_FLAGS	PTE_TYPE_PAGE | PTE_AF
+#define PMD_FLAGS	PMD_TYPE_SECT | PMD_SECT_AF
+#else
+#define PTE_FLAGS	PTE_TYPE_PAGE | PTE_AF | PTE_SHARED
+#define PMD_FLAGS	PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S
+#endif
+
+#ifdef CONFIG_ARM64_64K_PAGES
+#define MM_MMUFLAGS	PTE_ATTRINDX(MT_NORMAL) | PTE_FLAGS
+#else
+#define MM_MMUFLAGS	PMD_ATTRINDX(MT_NORMAL) | PMD_FLAGS
+#endif
+
+/*
+ * Kernel startup entry point.
+ * ---------------------------
+ *
+ * The requirements are:
+ *   MMU = off, D-cache = off, I-cache = on or off,
+ *   x0 = physical address to the FDT blob.
+ *
+ * This code is mostly position independent so you call this at
+ * __pa(PAGE_OFFSET + TEXT_OFFSET).
+ *
+ * Note that the callee-saved registers are used for storing variables
+ * that are useful before the MMU is enabled. The allocations are described
+ * in the entry routines.
+ */
+	__HEAD
+
+	/*
+	 * DO NOT MODIFY. Image header expected by Linux boot-loaders.
+	 */
+#ifdef CONFIG_EFI
+efi_head:
+	/*
+	 * This add instruction has no meaningful effect except that
+	 * its opcode forms the magic "MZ" signature required by UEFI.
+	 */
+	add	x13, x18, #0x16
+	b	stext
+#else
+	b	stext				// branch to kernel start, magic
+	.long	0				// reserved
+#endif
+	.quad	_kernel_offset_le		// Image load offset from start of RAM, little-endian
+	.quad	_kernel_size_le			// Effective size of kernel image, little-endian
+	.quad	_kernel_flags_le		// Informative flags, little-endian
+	.quad	0				// reserved
+	.quad	0				// reserved
+	.quad	0				// reserved
+	.byte	0x41				// Magic number, "ARM\x64"
+	.byte	0x52
+	.byte	0x4d
+	.byte	0x64
+#ifdef CONFIG_EFI
+	.long	pe_header - efi_head		// Offset to the PE header.
+#else
+	.word	0				// reserved
+#endif
+
+#ifdef CONFIG_EFI
+	.align 3
+pe_header:
+	.ascii	"PE"
+	.short 	0
+coff_header:
+	.short	0xaa64				// AArch64
+	.short	2				// nr_sections
+	.long	0 				// TimeDateStamp
+	.long	0				// PointerToSymbolTable
+	.long	1				// NumberOfSymbols
+	.short	section_table - optional_header	// SizeOfOptionalHeader
+	.short	0x206				// Characteristics.
+						// IMAGE_FILE_DEBUG_STRIPPED |
+						// IMAGE_FILE_EXECUTABLE_IMAGE |
+						// IMAGE_FILE_LINE_NUMS_STRIPPED
+optional_header:
+	.short	0x20b				// PE32+ format
+	.byte	0x02				// MajorLinkerVersion
+	.byte	0x14				// MinorLinkerVersion
+	.long	_end - stext			// SizeOfCode
+	.long	0				// SizeOfInitializedData
+	.long	0				// SizeOfUninitializedData
+	.long	efi_stub_entry - efi_head	// AddressOfEntryPoint
+	.long	stext - efi_head		// BaseOfCode
+
+extra_header_fields:
+	.quad	0				// ImageBase
+	.long	0x20				// SectionAlignment
+	.long	0x8				// FileAlignment
+	.short	0				// MajorOperatingSystemVersion
+	.short	0				// MinorOperatingSystemVersion
+	.short	0				// MajorImageVersion
+	.short	0				// MinorImageVersion
+	.short	0				// MajorSubsystemVersion
+	.short	0				// MinorSubsystemVersion
+	.long	0				// Win32VersionValue
+
+	.long	_end - efi_head			// SizeOfImage
+
+	// Everything before the kernel image is considered part of the header
+	.long	stext - efi_head		// SizeOfHeaders
+	.long	0				// CheckSum
+	.short	0xa				// Subsystem (EFI application)
+	.short	0				// DllCharacteristics
+	.quad	0				// SizeOfStackReserve
+	.quad	0				// SizeOfStackCommit
+	.quad	0				// SizeOfHeapReserve
+	.quad	0				// SizeOfHeapCommit
+	.long	0				// LoaderFlags
+	.long	0x6				// NumberOfRvaAndSizes
+
+	.quad	0				// ExportTable
+	.quad	0				// ImportTable
+	.quad	0				// ResourceTable
+	.quad	0				// ExceptionTable
+	.quad	0				// CertificationTable
+	.quad	0				// BaseRelocationTable
+
+	// Section table
+section_table:
+
+	/*
+	 * The EFI application loader requires a relocation section
+	 * because EFI applications must be relocatable.  This is a
+	 * dummy section as far as we are concerned.
+	 */
+	.ascii	".reloc"
+	.byte	0
+	.byte	0			// end of 0 padding of section name
+	.long	0
+	.long	0
+	.long	0			// SizeOfRawData
+	.long	0			// PointerToRawData
+	.long	0			// PointerToRelocations
+	.long	0			// PointerToLineNumbers
+	.short	0			// NumberOfRelocations
+	.short	0			// NumberOfLineNumbers
+	.long	0x42100040		// Characteristics (section flags)
+
+
+	.ascii	".text"
+	.byte	0
+	.byte	0
+	.byte	0        		// end of 0 padding of section name
+	.long	_end - stext		// VirtualSize
+	.long	stext - efi_head	// VirtualAddress
+	.long	_edata - stext		// SizeOfRawData
+	.long	stext - efi_head	// PointerToRawData
+
+	.long	0		// PointerToRelocations (0 for executables)
+	.long	0		// PointerToLineNumbers (0 for executables)
+	.short	0		// NumberOfRelocations  (0 for executables)
+	.short	0		// NumberOfLineNumbers  (0 for executables)
+	.long	0xe0500020	// Characteristics (section flags)
+	.align 5
+#endif
+
+ENTRY(stext)
+	mov	x21, x0				// x21=FDT
+	bl	el2_setup			// Drop to EL1, w20=cpu_boot_mode
+	bl	__calc_phys_offset		// x24=PHYS_OFFSET, x28=PHYS_OFFSET-PAGE_OFFSET
+	bl	set_cpu_boot_mode_flag
+	mrs	x22, midr_el1			// x22=cpuid
+	mov	x0, x22
+	bl	lookup_processor_type
+	mov	x23, x0				// x23=current cpu_table
+	cbz	x23, __error_p			// invalid processor (x23=0)?
+	bl	__vet_fdt
+	bl	__create_page_tables		// x25=TTBR0, x26=TTBR1
+	/*
+	 * The following calls CPU specific code in a position independent
+	 * manner. See arch/arm64/mm/proc.S for details. x23 = base of
+	 * cpu_info structure selected by lookup_processor_type above.
+	 * On return, the CPU will be ready for the MMU to be turned on and
+	 * the TCR will have been set.
+	 */
+	ldr	x27, __switch_data		// address to jump to after
+						// MMU has been enabled
+	adr	lr, __enable_mmu		// return (PIC) address
+	ldr	x12, [x23, #CPU_INFO_SETUP]
+	add	x12, x12, x28			// __virt_to_phys
+	br	x12				// initialise processor
+ENDPROC(stext)
+
+/*
+ * If we're fortunate enough to boot at EL2, ensure that the world is
+ * sane before dropping to EL1.
+ *
+ * Returns either BOOT_CPU_MODE_EL1 or BOOT_CPU_MODE_EL2 in x20 if
+ * booted in EL1 or EL2 respectively.
+ */
+ENTRY(el2_setup)
+	mrs	x0, CurrentEL
+	cmp	x0, #CurrentEL_EL2
+	b.ne	1f
+	mrs	x0, sctlr_el2
+CPU_BE(	orr	x0, x0, #(1 << 25)	)	// Set the EE bit for EL2
+CPU_LE(	bic	x0, x0, #(1 << 25)	)	// Clear the EE bit for EL2
+	msr	sctlr_el2, x0
+	b	2f
+1:	mrs	x0, sctlr_el1
+CPU_BE(	orr	x0, x0, #(3 << 24)	)	// Set the EE and E0E bits for EL1
+CPU_LE(	bic	x0, x0, #(3 << 24)	)	// Clear the EE and E0E bits for EL1
+	msr	sctlr_el1, x0
+	mov	w20, #BOOT_CPU_MODE_EL1		// This cpu booted in EL1
+	isb
+	ret
+
+	/* Hyp configuration. */
+2:	mov	x0, #(1 << 31)			// 64-bit EL1
+	msr	hcr_el2, x0
+
+	/* Generic timers. */
+	mrs	x0, cnthctl_el2
+	orr	x0, x0, #3			// Enable EL1 physical timers
+	msr	cnthctl_el2, x0
+	msr	cntvoff_el2, xzr		// Clear virtual offset
+
+#ifdef CONFIG_ARM_GIC_V3
+	/* GICv3 system register access */
+	mrs	x0, id_aa64pfr0_el1
+	ubfx	x0, x0, #24, #4
+	cmp	x0, #1
+	b.ne	3f
+
+	mrs_s	x0, ICC_SRE_EL2
+	orr	x0, x0, #ICC_SRE_EL2_SRE	// Set ICC_SRE_EL2.SRE==1
+	orr	x0, x0, #ICC_SRE_EL2_ENABLE	// Set ICC_SRE_EL2.Enable==1
+	msr_s	ICC_SRE_EL2, x0
+	isb					// Make sure SRE is now set
+	msr_s	ICH_HCR_EL2, xzr		// Reset ICC_HCR_EL2 to defaults
+
+3:
+#endif
+
+	/* Populate ID registers. */
+	mrs	x0, midr_el1
+	mrs	x1, mpidr_el1
+	msr	vpidr_el2, x0
+	msr	vmpidr_el2, x1
+
+	/* sctlr_el1 */
+	mov	x0, #0x0800			// Set/clear RES{1,0} bits
+CPU_BE(	movk	x0, #0x33d0, lsl #16	)	// Set EE and E0E on BE systems
+CPU_LE(	movk	x0, #0x30d0, lsl #16	)	// Clear EE and E0E on LE systems
+	msr	sctlr_el1, x0
+
+	/* Coprocessor traps. */
+	mov	x0, #0x33ff
+	msr	cptr_el2, x0			// Disable copro. traps to EL2
+
+#ifdef CONFIG_COMPAT
+	msr	hstr_el2, xzr			// Disable CP15 traps to EL2
+#endif
+
+	/* Stage-2 translation */
+	msr	vttbr_el2, xzr
+
+	/* Hypervisor stub */
+	adr	x0, __hyp_stub_vectors
+	msr	vbar_el2, x0
+
+	/* spsr */
+	mov	x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
+		      PSR_MODE_EL1h)
+	msr	spsr_el2, x0
+	msr	elr_el2, lr
+	mov	w20, #BOOT_CPU_MODE_EL2		// This CPU booted in EL2
+	eret
+ENDPROC(el2_setup)
+
+/*
+ * Sets the __boot_cpu_mode flag depending on the CPU boot mode passed
+ * in x20. See arch/arm64/include/asm/virt.h for more info.
+ */
+ENTRY(set_cpu_boot_mode_flag)
+	ldr	x1, =__boot_cpu_mode		// Compute __boot_cpu_mode
+	add	x1, x1, x28
+	cmp	w20, #BOOT_CPU_MODE_EL2
+	b.ne	1f
+	add	x1, x1, #4
+1:	str	w20, [x1]			// This CPU has booted in EL1
+	dmb	sy
+	dc	ivac, x1			// Invalidate potentially stale cache line
+	ret
+ENDPROC(set_cpu_boot_mode_flag)
+
+/*
+ * We need to find out the CPU boot mode long after boot, so we need to
+ * store it in a writable variable.
+ *
+ * This is not in .bss, because we set it sufficiently early that the boot-time
+ * zeroing of .bss would clobber it.
+ */
+	.pushsection	.data..cacheline_aligned
+ENTRY(__boot_cpu_mode)
+	.align	L1_CACHE_SHIFT
+	.long	BOOT_CPU_MODE_EL2
+	.long	0
+	.popsection
+
+#ifdef CONFIG_SMP
+	.align	3
+1:	.quad	.
+	.quad	secondary_holding_pen_release
+
+	/*
+	 * This provides a "holding pen" for platforms to hold all secondary
+	 * cores are held until we're ready for them to initialise.
+	 */
+ENTRY(secondary_holding_pen)
+	bl	el2_setup			// Drop to EL1, w20=cpu_boot_mode
+	bl	__calc_phys_offset		// x24=PHYS_OFFSET, x28=PHYS_OFFSET-PAGE_OFFSET
+	bl	set_cpu_boot_mode_flag
+	mrs	x0, mpidr_el1
+	ldr     x1, =MPIDR_HWID_BITMASK
+	and	x0, x0, x1
+	adr	x1, 1b
+	ldp	x2, x3, [x1]
+	sub	x1, x1, x2
+	add	x3, x3, x1
+pen:	ldr	x4, [x3]
+	cmp	x4, x0
+	b.eq	secondary_startup
+	wfe
+	b	pen
+ENDPROC(secondary_holding_pen)
+
+	/*
+	 * Secondary entry point that jumps straight into the kernel. Only to
+	 * be used where CPUs are brought online dynamically by the kernel.
+	 */
+ENTRY(secondary_entry)
+	bl	el2_setup			// Drop to EL1
+	bl	__calc_phys_offset		// x24=PHYS_OFFSET, x28=PHYS_OFFSET-PAGE_OFFSET
+	bl	set_cpu_boot_mode_flag
+	b	secondary_startup
+ENDPROC(secondary_entry)
+
+ENTRY(secondary_startup)
+	/*
+	 * Common entry point for secondary CPUs.
+	 */
+	mrs	x22, midr_el1			// x22=cpuid
+	mov	x0, x22
+	bl	lookup_processor_type
+	mov	x23, x0				// x23=current cpu_table
+	cbz	x23, __error_p			// invalid processor (x23=0)?
+
+	pgtbl	x25, x26, x28			// x25=TTBR0, x26=TTBR1
+	ldr	x12, [x23, #CPU_INFO_SETUP]
+	add	x12, x12, x28			// __virt_to_phys
+	blr	x12				// initialise processor
+
+	ldr	x21, =secondary_data
+	ldr	x27, =__secondary_switched	// address to jump to after enabling the MMU
+	b	__enable_mmu
+ENDPROC(secondary_startup)
+
+ENTRY(__secondary_switched)
+	ldr	x0, [x21]			// get secondary_data.stack
+	mov	sp, x0
+	mov	x29, #0
+	b	secondary_start_kernel
+ENDPROC(__secondary_switched)
+#endif	/* CONFIG_SMP */
+
+/*
+ * Setup common bits before finally enabling the MMU. Essentially this is just
+ * loading the page table pointer and vector base registers.
+ *
+ * On entry to this code, x0 must contain the SCTLR_EL1 value for turning on
+ * the MMU.
+ */
+__enable_mmu:
+	ldr	x5, =vectors
+	msr	vbar_el1, x5
+	msr	ttbr0_el1, x25			// load TTBR0
+	msr	ttbr1_el1, x26			// load TTBR1
+	isb
+	b	__turn_mmu_on
+ENDPROC(__enable_mmu)
+
+/*
+ * Enable the MMU. This completely changes the structure of the visible memory
+ * space. You will not be able to trace execution through this.
+ *
+ *  x0  = system control register
+ *  x27 = *virtual* address to jump to upon completion
+ *
+ * other registers depend on the function called upon completion
+ *
+ * We align the entire function to the smallest power of two larger than it to
+ * ensure it fits within a single block map entry. Otherwise were PHYS_OFFSET
+ * close to the end of a 512MB or 1GB block we might require an additional
+ * table to map the entire function.
+ */
+	.align	4
+__turn_mmu_on:
+	msr	sctlr_el1, x0
+	isb
+	br	x27
+ENDPROC(__turn_mmu_on)
+
+/*
+ * Calculate the start of physical memory.
+ */
+__calc_phys_offset:
+	adr	x0, 1f
+	ldp	x1, x2, [x0]
+	sub	x28, x0, x1			// x28 = PHYS_OFFSET - PAGE_OFFSET
+	add	x24, x2, x28			// x24 = PHYS_OFFSET
+	ret
+ENDPROC(__calc_phys_offset)
+
+	.align 3
+1:	.quad	.
+	.quad	PAGE_OFFSET
+
+/*
+ * Macro to create a table entry to the next page.
+ *
+ *	tbl:	page table address
+ *	virt:	virtual address
+ *	shift:	#imm page table shift
+ *	ptrs:	#imm pointers per table page
+ *
+ * Preserves:	virt
+ * Corrupts:	tmp1, tmp2
+ * Returns:	tbl -> next level table page address
+ */
+	.macro	create_table_entry, tbl, virt, shift, ptrs, tmp1, tmp2
+	lsr	\tmp1, \virt, #\shift
+	and	\tmp1, \tmp1, #\ptrs - 1	// table index
+	add	\tmp2, \tbl, #PAGE_SIZE
+	orr	\tmp2, \tmp2, #PMD_TYPE_TABLE	// address of next table and entry type
+	str	\tmp2, [\tbl, \tmp1, lsl #3]
+	add	\tbl, \tbl, #PAGE_SIZE		// next level table page
+	.endm
+
+/*
+ * Macro to populate the PGD (and possibily PUD) for the corresponding
+ * block entry in the next level (tbl) for the given virtual address.
+ *
+ * Preserves:	tbl, next, virt
+ * Corrupts:	tmp1, tmp2
+ */
+	.macro	create_pgd_entry, tbl, virt, tmp1, tmp2
+	create_table_entry \tbl, \virt, PGDIR_SHIFT, PTRS_PER_PGD, \tmp1, \tmp2
+#if SWAPPER_PGTABLE_LEVELS == 3
+	create_table_entry \tbl, \virt, TABLE_SHIFT, PTRS_PER_PTE, \tmp1, \tmp2
+#endif
+	.endm
+
+/*
+ * Macro to populate block entries in the page table for the start..end
+ * virtual range (inclusive).
+ *
+ * Preserves:	tbl, flags
+ * Corrupts:	phys, start, end, pstate
+ */
+	.macro	create_block_map, tbl, flags, phys, start, end
+	lsr	\phys, \phys, #BLOCK_SHIFT
+	lsr	\start, \start, #BLOCK_SHIFT
+	and	\start, \start, #PTRS_PER_PTE - 1	// table index
+	orr	\phys, \flags, \phys, lsl #BLOCK_SHIFT	// table entry
+	lsr	\end, \end, #BLOCK_SHIFT
+	and	\end, \end, #PTRS_PER_PTE - 1		// table end index
+9999:	str	\phys, [\tbl, \start, lsl #3]		// store the entry
+	add	\start, \start, #1			// next entry
+	add	\phys, \phys, #BLOCK_SIZE		// next block
+	cmp	\start, \end
+	b.ls	9999b
+	.endm
+
+/*
+ * Setup the initial page tables. We only setup the barest amount which is
+ * required to get the kernel running. The following sections are required:
+ *   - identity mapping to enable the MMU (low address, TTBR0)
+ *   - first few MB of the kernel linear mapping to jump to once the MMU has
+ *     been enabled, including the FDT blob (TTBR1)
+ *   - pgd entry for fixed mappings (TTBR1)
+ */
+__create_page_tables:
+	pgtbl	x25, x26, x28			// idmap_pg_dir and swapper_pg_dir addresses
+	mov	x27, lr
+
+	/*
+	 * Invalidate the idmap and swapper page tables to avoid potential
+	 * dirty cache lines being evicted.
+	 */
+	mov	x0, x25
+	add	x1, x26, #SWAPPER_DIR_SIZE
+	bl	__inval_cache_range
+
+	/*
+	 * Clear the idmap and swapper page tables.
+	 */
+	mov	x0, x25
+	add	x6, x26, #SWAPPER_DIR_SIZE
+1:	stp	xzr, xzr, [x0], #16
+	stp	xzr, xzr, [x0], #16
+	stp	xzr, xzr, [x0], #16
+	stp	xzr, xzr, [x0], #16
+	cmp	x0, x6
+	b.lo	1b
+
+	ldr	x7, =MM_MMUFLAGS
+
+	/*
+	 * Create the identity mapping.
+	 */
+	mov	x0, x25				// idmap_pg_dir
+	ldr	x3, =KERNEL_START
+	add	x3, x3, x28			// __pa(KERNEL_START)
+	create_pgd_entry x0, x3, x5, x6
+	ldr	x6, =KERNEL_END
+	mov	x5, x3				// __pa(KERNEL_START)
+	add	x6, x6, x28			// __pa(KERNEL_END)
+	create_block_map x0, x7, x3, x5, x6
+
+	/*
+	 * Map the kernel image (starting with PHYS_OFFSET).
+	 */
+	mov	x0, x26				// swapper_pg_dir
+	mov	x5, #PAGE_OFFSET
+	create_pgd_entry x0, x5, x3, x6
+	ldr	x6, =KERNEL_END
+	mov	x3, x24				// phys offset
+	create_block_map x0, x7, x3, x5, x6
+
+	/*
+	 * Map the FDT blob (maximum 2MB; must be within 512MB of
+	 * PHYS_OFFSET).
+	 */
+	mov	x3, x21				// FDT phys address
+	and	x3, x3, #~((1 << 21) - 1)	// 2MB aligned
+	mov	x6, #PAGE_OFFSET
+	sub	x5, x3, x24			// subtract PHYS_OFFSET
+	tst	x5, #~((1 << 29) - 1)		// within 512MB?
+	csel	x21, xzr, x21, ne		// zero the FDT pointer
+	b.ne	1f
+	add	x5, x5, x6			// __va(FDT blob)
+	add	x6, x5, #1 << 21		// 2MB for the FDT blob
+	sub	x6, x6, #1			// inclusive range
+	create_block_map x0, x7, x3, x5, x6
+1:
+	/*
+	 * Since the page tables have been populated with non-cacheable
+	 * accesses (MMU disabled), invalidate the idmap and swapper page
+	 * tables again to remove any speculatively loaded cache lines.
+	 */
+	mov	x0, x25
+	add	x1, x26, #SWAPPER_DIR_SIZE
+	bl	__inval_cache_range
+
+	mov	lr, x27
+	ret
+ENDPROC(__create_page_tables)
+	.ltorg
+
+	.align	3
+	.type	__switch_data, %object
+__switch_data:
+	.quad	__mmap_switched
+	.quad	__bss_start			// x6
+	.quad	__bss_stop			// x7
+	.quad	processor_id			// x4
+	.quad	__fdt_pointer			// x5
+	.quad	memstart_addr			// x6
+	.quad	init_thread_union + THREAD_START_SP // sp
+
+/*
+ * The following fragment of code is executed with the MMU on in MMU mode, and
+ * uses absolute addresses; this is not position independent.
+ */
+__mmap_switched:
+	adr	x3, __switch_data + 8
+
+#ifdef CONFIG_TIMA_RKP
+	ldr	x6, =rkp_map_bitmap
+	add	x7, x6, 0x18000
+3:	cmp	x6, x7
+	b.hs	4f
+	str	xzr, [x6], #8			// Clear BSS
+	b	3b
+#endif
+4:	ldp	x6, x7, [x3], #16
+1:	cmp	x6, x7
+	b.hs	2f
+	str	xzr, [x6], #8			// Clear BSS
+	b	1b
+2:
+	ldp	x4, x5, [x3], #16
+	ldr	x6, [x3], #8
+	ldr	x16, [x3]
+	mov	sp, x16
+	str	x22, [x4]			// Save processor ID
+	str	x21, [x5]			// Save FDT pointer
+	str	x24, [x6]			// Save PHYS_OFFSET
+	mov	x29, #0
+	b	start_kernel
+ENDPROC(__mmap_switched)
+
+/*
+ * Exception handling. Something went wrong and we can't proceed. We ought to
+ * tell the user, but since we don't have any guarantee that we're even
+ * running on the right architecture, we do virtually nothing.
+ */
+__error_p:
+ENDPROC(__error_p)
+
+__error:
+1:	nop
+	b	1b
+ENDPROC(__error)
+
+/*
+ * This function gets the processor ID in w0 and searches the cpu_table[] for
+ * a match. It returns a pointer to the struct cpu_info it found. The
+ * cpu_table[] must end with an empty (all zeros) structure.
+ *
+ * This routine can be called via C code and it needs to work with the MMU
+ * both disabled and enabled (the offset is calculated automatically).
+ */
+ENTRY(lookup_processor_type)
+	adr	x1, __lookup_processor_type_data
+	ldp	x2, x3, [x1]
+	sub	x1, x1, x2			// get offset between VA and PA
+	add	x3, x3, x1			// convert VA to PA
+1:
+	ldp	w5, w6, [x3]			// load cpu_id_val and cpu_id_mask
+	cbz	w5, 2f				// end of list?
+	and	w6, w6, w0
+	cmp	w5, w6
+	b.eq	3f
+	add	x3, x3, #CPU_INFO_SZ
+	b	1b
+2:
+	mov	x3, #0				// unknown processor
+3:
+	mov	x0, x3
+	ret
+ENDPROC(lookup_processor_type)
+
+	.align	3
+	.type	__lookup_processor_type_data, %object
+__lookup_processor_type_data:
+	.quad	.
+	.quad	cpu_table
+	.size	__lookup_processor_type_data, . - __lookup_processor_type_data
+
+/*
+ * Determine validity of the x21 FDT pointer.
+ * The dtb must be 8-byte aligned and live in the first 512M of memory.
+ */
+__vet_fdt:
+	tst	x21, #0x7
+	b.ne	1f
+	cmp	x21, x24
+	b.lt	1f
+	mov	x0, #(1 << 29)
+	add	x0, x0, x24
+	cmp	x21, x0
+	b.ge	1f
+	ret
+1:
+	mov	x21, #0
+	ret
+ENDPROC(__vet_fdt)

arch/arm64/kernel/hw_breakpoint.c

@@ -0,0 +1,954 @@
+/*
+ * HW_breakpoint: a unified kernel/user-space hardware breakpoint facility,
+ * using the CPU's debug registers.
+ *
+ * Copyright (C) 2012 ARM Limited
+ * Author: Will Deacon <will.deacon@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define pr_fmt(fmt) "hw-breakpoint: " fmt
+
+#include <linux/compat.h>
+#include <linux/cpu_pm.h>
+#include <linux/errno.h>
+#include <linux/hw_breakpoint.h>
+#include <linux/perf_event.h>
+#include <linux/ptrace.h>
+#include <linux/smp.h>
+
+#include <asm/current.h>
+#include <asm/debug-monitors.h>
+#include <asm/hw_breakpoint.h>
+#include <asm/kdebug.h>
+#include <asm/traps.h>
+#include <asm/cputype.h>
+#include <asm/system_misc.h>
+
+/* Breakpoint currently in use for each BRP. */
+static DEFINE_PER_CPU(struct perf_event *, bp_on_reg[ARM_MAX_BRP]);
+
+/* Watchpoint currently in use for each WRP. */
+static DEFINE_PER_CPU(struct perf_event *, wp_on_reg[ARM_MAX_WRP]);
+
+/* Currently stepping a per-CPU kernel breakpoint. */
+static DEFINE_PER_CPU(int, stepping_kernel_bp);
+
+/* Number of BRP/WRP registers on this CPU. */
+static int core_num_brps;
+static int core_num_wrps;
+
+/* Determine number of BRP registers available. */
+static int get_num_brps(void)
+{
+	return ((read_cpuid(ID_AA64DFR0_EL1) >> 12) & 0xf) + 1;
+}
+
+/* Determine number of WRP registers available. */
+static int get_num_wrps(void)
+{
+	return ((read_cpuid(ID_AA64DFR0_EL1) >> 20) & 0xf) + 1;
+}
+
+int hw_breakpoint_slots(int type)
+{
+	/*
+	 * We can be called early, so don't rely on
+	 * our static variables being initialised.
+	 */
+	switch (type) {
+	case TYPE_INST:
+		return get_num_brps();
+	case TYPE_DATA:
+		return get_num_wrps();
+	default:
+		pr_warning("unknown slot type: %d\n", type);
+		return 0;
+	}
+}
+
+#define READ_WB_REG_CASE(OFF, N, REG, VAL)	\
+	case (OFF + N):				\
+		AARCH64_DBG_READ(N, REG, VAL);	\
+		break
+
+#define WRITE_WB_REG_CASE(OFF, N, REG, VAL)	\
+	case (OFF + N):				\
+		AARCH64_DBG_WRITE(N, REG, VAL);	\
+		break
+
+#define GEN_READ_WB_REG_CASES(OFF, REG, VAL)	\
+	READ_WB_REG_CASE(OFF,  0, REG, VAL);	\
+	READ_WB_REG_CASE(OFF,  1, REG, VAL);	\
+	READ_WB_REG_CASE(OFF,  2, REG, VAL);	\
+	READ_WB_REG_CASE(OFF,  3, REG, VAL);	\
+	READ_WB_REG_CASE(OFF,  4, REG, VAL);	\
+	READ_WB_REG_CASE(OFF,  5, REG, VAL);	\
+	READ_WB_REG_CASE(OFF,  6, REG, VAL);	\
+	READ_WB_REG_CASE(OFF,  7, REG, VAL);	\
+	READ_WB_REG_CASE(OFF,  8, REG, VAL);	\
+	READ_WB_REG_CASE(OFF,  9, REG, VAL);	\
+	READ_WB_REG_CASE(OFF, 10, REG, VAL);	\
+	READ_WB_REG_CASE(OFF, 11, REG, VAL);	\
+	READ_WB_REG_CASE(OFF, 12, REG, VAL);	\
+	READ_WB_REG_CASE(OFF, 13, REG, VAL);	\
+	READ_WB_REG_CASE(OFF, 14, REG, VAL);	\
+	READ_WB_REG_CASE(OFF, 15, REG, VAL)
+
+#define GEN_WRITE_WB_REG_CASES(OFF, REG, VAL)	\
+	WRITE_WB_REG_CASE(OFF,  0, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF,  1, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF,  2, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF,  3, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF,  4, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF,  5, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF,  6, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF,  7, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF,  8, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF,  9, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF, 10, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF, 11, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF, 12, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF, 13, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF, 14, REG, VAL);	\
+	WRITE_WB_REG_CASE(OFF, 15, REG, VAL)
+
+static u64 read_wb_reg(int reg, int n)
+{
+	u64 val = 0;
+
+	switch (reg + n) {
+	GEN_READ_WB_REG_CASES(AARCH64_DBG_REG_BVR, AARCH64_DBG_REG_NAME_BVR, val);
+	GEN_READ_WB_REG_CASES(AARCH64_DBG_REG_BCR, AARCH64_DBG_REG_NAME_BCR, val);
+	GEN_READ_WB_REG_CASES(AARCH64_DBG_REG_WVR, AARCH64_DBG_REG_NAME_WVR, val);
+	GEN_READ_WB_REG_CASES(AARCH64_DBG_REG_WCR, AARCH64_DBG_REG_NAME_WCR, val);
+	default:
+		pr_warning("attempt to read from unknown breakpoint register %d\n", n);
+	}
+
+	return val;
+}
+
+static void write_wb_reg(int reg, int n, u64 val)
+{
+	switch (reg + n) {
+	GEN_WRITE_WB_REG_CASES(AARCH64_DBG_REG_BVR, AARCH64_DBG_REG_NAME_BVR, val);
+	GEN_WRITE_WB_REG_CASES(AARCH64_DBG_REG_BCR, AARCH64_DBG_REG_NAME_BCR, val);
+	GEN_WRITE_WB_REG_CASES(AARCH64_DBG_REG_WVR, AARCH64_DBG_REG_NAME_WVR, val);
+	GEN_WRITE_WB_REG_CASES(AARCH64_DBG_REG_WCR, AARCH64_DBG_REG_NAME_WCR, val);
+	default:
+		pr_warning("attempt to write to unknown breakpoint register %d\n", n);
+	}
+	isb();
+}
+
+/*
+ * Convert a breakpoint privilege level to the corresponding exception
+ * level.
+ */
+static enum debug_el debug_exception_level(int privilege)
+{
+	switch (privilege) {
+	case AARCH64_BREAKPOINT_EL0:
+		return DBG_ACTIVE_EL0;
+	case AARCH64_BREAKPOINT_EL1:
+		return DBG_ACTIVE_EL1;
+	default:
+		pr_warning("invalid breakpoint privilege level %d\n", privilege);
+		return -EINVAL;
+	}
+}
+
+enum hw_breakpoint_ops {
+	HW_BREAKPOINT_INSTALL,
+	HW_BREAKPOINT_UNINSTALL,
+	HW_BREAKPOINT_RESTORE
+};
+
+/**
+ * hw_breakpoint_slot_setup - Find and setup a perf slot according to
+ *			      operations
+ *
+ * @slots: pointer to array of slots
+ * @max_slots: max number of slots
+ * @bp: perf_event to setup
+ * @ops: operation to be carried out on the slot
+ *
+ * Return:
+ *	slot index on success
+ *	-ENOSPC if no slot is available/matches
+ *	-EINVAL on wrong operations parameter
+ */
+static int hw_breakpoint_slot_setup(struct perf_event **slots, int max_slots,
+				    struct perf_event *bp,
+				    enum hw_breakpoint_ops ops)
+{
+	int i;
+	struct perf_event **slot;
+
+	for (i = 0; i < max_slots; ++i) {
+		slot = &slots[i];
+		switch (ops) {
+		case HW_BREAKPOINT_INSTALL:
+			if (!*slot) {
+				*slot = bp;
+				return i;
+			}
+			break;
+		case HW_BREAKPOINT_UNINSTALL:
+			if (*slot == bp) {
+				*slot = NULL;
+				return i;
+			}
+			break;
+		case HW_BREAKPOINT_RESTORE:
+			if (*slot == bp)
+				return i;
+			break;
+		default:
+			pr_warn_once("Unhandled hw breakpoint ops %d\n", ops);
+			return -EINVAL;
+		}
+	}
+	return -ENOSPC;
+}
+
+static int hw_breakpoint_control(struct perf_event *bp,
+				 enum hw_breakpoint_ops ops)
+{
+	struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+	struct perf_event **slots;
+	struct debug_info *debug_info = &current->thread.debug;
+	int i, max_slots, ctrl_reg, val_reg, reg_enable;
+	enum debug_el dbg_el = debug_exception_level(info->ctrl.privilege);
+	u32 ctrl;
+
+	if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
+		/* Breakpoint */
+		ctrl_reg = AARCH64_DBG_REG_BCR;
+		val_reg = AARCH64_DBG_REG_BVR;
+		slots = this_cpu_ptr(bp_on_reg);
+		max_slots = core_num_brps;
+		reg_enable = !debug_info->bps_disabled;
+	} else {
+		/* Watchpoint */
+		ctrl_reg = AARCH64_DBG_REG_WCR;
+		val_reg = AARCH64_DBG_REG_WVR;
+		slots = this_cpu_ptr(wp_on_reg);
+		max_slots = core_num_wrps;
+		reg_enable = !debug_info->wps_disabled;
+	}
+
+	i = hw_breakpoint_slot_setup(slots, max_slots, bp, ops);
+
+	if (WARN_ONCE(i < 0, "Can't find any breakpoint slot"))
+		return i;
+
+	switch (ops) {
+	case HW_BREAKPOINT_INSTALL:
+		/*
+		 * Ensure debug monitors are enabled at the correct exception
+		 * level.
+		 */
+		enable_debug_monitors(dbg_el);
+		/* Fall through */
+	case HW_BREAKPOINT_RESTORE:
+		/* Setup the address register. */
+		write_wb_reg(val_reg, i, info->address);
+
+		/* Setup the control register. */
+		ctrl = encode_ctrl_reg(info->ctrl);
+		write_wb_reg(ctrl_reg, i,
+			     reg_enable ? ctrl | 0x1 : ctrl & ~0x1);
+		break;
+	case HW_BREAKPOINT_UNINSTALL:
+		/* Reset the control register. */
+		write_wb_reg(ctrl_reg, i, 0);
+
+		/*
+		 * Release the debug monitors for the correct exception
+		 * level.
+		 */
+		disable_debug_monitors(dbg_el);
+		break;
+	}
+
+	return 0;
+}
+
+/*
+ * Install a perf counter breakpoint.
+ */
+int arch_install_hw_breakpoint(struct perf_event *bp)
+{
+	return hw_breakpoint_control(bp, HW_BREAKPOINT_INSTALL);
+}
+
+void arch_uninstall_hw_breakpoint(struct perf_event *bp)
+{
+	hw_breakpoint_control(bp, HW_BREAKPOINT_UNINSTALL);
+}
+
+static int get_hbp_len(u8 hbp_len)
+{
+	unsigned int len_in_bytes = 0;
+
+	switch (hbp_len) {
+	case ARM_BREAKPOINT_LEN_1:
+		len_in_bytes = 1;
+		break;
+	case ARM_BREAKPOINT_LEN_2:
+		len_in_bytes = 2;
+		break;
+	case ARM_BREAKPOINT_LEN_4:
+		len_in_bytes = 4;
+		break;
+	case ARM_BREAKPOINT_LEN_8:
+		len_in_bytes = 8;
+		break;
+	}
+
+	return len_in_bytes;
+}
+
+/*
+ * Check whether bp virtual address is in kernel space.
+ */
+int arch_check_bp_in_kernelspace(struct perf_event *bp)
+{
+	unsigned int len;
+	unsigned long va;
+	struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+
+	va = info->address;
+	len = get_hbp_len(info->ctrl.len);
+
+	return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
+}
+
+/*
+ * Extract generic type and length encodings from an arch_hw_breakpoint_ctrl.
+ * Hopefully this will disappear when ptrace can bypass the conversion
+ * to generic breakpoint descriptions.
+ */
+int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
+			   int *gen_len, int *gen_type)
+{
+	/* Type */
+	switch (ctrl.type) {
+	case ARM_BREAKPOINT_EXECUTE:
+		*gen_type = HW_BREAKPOINT_X;
+		break;
+	case ARM_BREAKPOINT_LOAD:
+		*gen_type = HW_BREAKPOINT_R;
+		break;
+	case ARM_BREAKPOINT_STORE:
+		*gen_type = HW_BREAKPOINT_W;
+		break;
+	case ARM_BREAKPOINT_LOAD | ARM_BREAKPOINT_STORE:
+		*gen_type = HW_BREAKPOINT_RW;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Len */
+	switch (ctrl.len) {
+	case ARM_BREAKPOINT_LEN_1:
+		*gen_len = HW_BREAKPOINT_LEN_1;
+		break;
+	case ARM_BREAKPOINT_LEN_2:
+		*gen_len = HW_BREAKPOINT_LEN_2;
+		break;
+	case ARM_BREAKPOINT_LEN_4:
+		*gen_len = HW_BREAKPOINT_LEN_4;
+		break;
+	case ARM_BREAKPOINT_LEN_8:
+		*gen_len = HW_BREAKPOINT_LEN_8;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * Construct an arch_hw_breakpoint from a perf_event.
+ */
+static int arch_build_bp_info(struct perf_event *bp)
+{
+	struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+
+	/* Type */
+	switch (bp->attr.bp_type) {
+	case HW_BREAKPOINT_X:
+		info->ctrl.type = ARM_BREAKPOINT_EXECUTE;
+		break;
+	case HW_BREAKPOINT_R:
+		info->ctrl.type = ARM_BREAKPOINT_LOAD;
+		break;
+	case HW_BREAKPOINT_W:
+		info->ctrl.type = ARM_BREAKPOINT_STORE;
+		break;
+	case HW_BREAKPOINT_RW:
+		info->ctrl.type = ARM_BREAKPOINT_LOAD | ARM_BREAKPOINT_STORE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Len */
+	switch (bp->attr.bp_len) {
+	case HW_BREAKPOINT_LEN_1:
+		info->ctrl.len = ARM_BREAKPOINT_LEN_1;
+		break;
+	case HW_BREAKPOINT_LEN_2:
+		info->ctrl.len = ARM_BREAKPOINT_LEN_2;
+		break;
+	case HW_BREAKPOINT_LEN_4:
+		info->ctrl.len = ARM_BREAKPOINT_LEN_4;
+		break;
+	case HW_BREAKPOINT_LEN_8:
+		info->ctrl.len = ARM_BREAKPOINT_LEN_8;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/*
+	 * On AArch64, we only permit breakpoints of length 4, whereas
+	 * AArch32 also requires breakpoints of length 2 for Thumb.
+	 * Watchpoints can be of length 1, 2, 4 or 8 bytes.
+	 */
+	if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
+		if (is_compat_task()) {
+			if (info->ctrl.len != ARM_BREAKPOINT_LEN_2 &&
+			    info->ctrl.len != ARM_BREAKPOINT_LEN_4)
+				return -EINVAL;
+		} else if (info->ctrl.len != ARM_BREAKPOINT_LEN_4) {
+			/*
+			 * FIXME: Some tools (I'm looking at you perf) assume
+			 *	  that breakpoints should be sizeof(long). This
+			 *	  is nonsense. For now, we fix up the parameter
+			 *	  but we should probably return -EINVAL instead.
+			 */
+			info->ctrl.len = ARM_BREAKPOINT_LEN_4;
+		}
+	}
+
+	/* Address */
+	info->address = bp->attr.bp_addr;
+
+	/*
+	 * Privilege
+	 * Note that we disallow combined EL0/EL1 breakpoints because
+	 * that would complicate the stepping code.
+	 */
+	if (arch_check_bp_in_kernelspace(bp))
+		info->ctrl.privilege = AARCH64_BREAKPOINT_EL1;
+	else
+		info->ctrl.privilege = AARCH64_BREAKPOINT_EL0;
+
+	/* Enabled? */
+	info->ctrl.enabled = !bp->attr.disabled;
+
+	return 0;
+}
+
+/*
+ * Validate the arch-specific HW Breakpoint register settings.
+ */
+int arch_validate_hwbkpt_settings(struct perf_event *bp)
+{
+	struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+	int ret;
+	u64 alignment_mask, offset;
+
+	/* Build the arch_hw_breakpoint. */
+	ret = arch_build_bp_info(bp);
+	if (ret)
+		return ret;
+
+	/*
+	 * Check address alignment.
+	 * We don't do any clever alignment correction for watchpoints
+	 * because using 64-bit unaligned addresses is deprecated for
+	 * AArch64.
+	 *
+	 * AArch32 tasks expect some simple alignment fixups, so emulate
+	 * that here.
+	 */
+	if (is_compat_task()) {
+		if (info->ctrl.len == ARM_BREAKPOINT_LEN_8)
+			alignment_mask = 0x7;
+		else
+			alignment_mask = 0x3;
+		offset = info->address & alignment_mask;
+		switch (offset) {
+		case 0:
+			/* Aligned */
+			break;
+		case 1:
+			/* Allow single byte watchpoint. */
+			if (info->ctrl.len == ARM_BREAKPOINT_LEN_1)
+				break;
+		case 2:
+			/* Allow halfword watchpoints and breakpoints. */
+			if (info->ctrl.len == ARM_BREAKPOINT_LEN_2)
+				break;
+		default:
+			return -EINVAL;
+		}
+
+		info->address &= ~alignment_mask;
+		info->ctrl.len <<= offset;
+	} else {
+		if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE)
+			alignment_mask = 0x3;
+		else
+			alignment_mask = 0x7;
+		if (info->address & alignment_mask)
+			return -EINVAL;
+	}
+
+	/*
+	 * Disallow per-task kernel breakpoints since these would
+	 * complicate the stepping code.
+	 */
+	if (info->ctrl.privilege == AARCH64_BREAKPOINT_EL1 && bp->hw.bp_target)
+		return -EINVAL;
+
+	return 0;
+}
+
+/*
+ * Enable/disable all of the breakpoints active at the specified
+ * exception level at the register level.
+ * This is used when single-stepping after a breakpoint exception.
+ */
+static void toggle_bp_registers(int reg, enum debug_el el, int enable)
+{
+	int i, max_slots, privilege;
+	u32 ctrl;
+	struct perf_event **slots;
+
+	switch (reg) {
+	case AARCH64_DBG_REG_BCR:
+		slots = this_cpu_ptr(bp_on_reg);
+		max_slots = core_num_brps;
+		break;
+	case AARCH64_DBG_REG_WCR:
+		slots = this_cpu_ptr(wp_on_reg);
+		max_slots = core_num_wrps;
+		break;
+	default:
+		return;
+	}
+
+	for (i = 0; i < max_slots; ++i) {
+		if (!slots[i])
+			continue;
+
+		privilege = counter_arch_bp(slots[i])->ctrl.privilege;
+		if (debug_exception_level(privilege) != el)
+			continue;
+
+		ctrl = read_wb_reg(reg, i);
+		if (enable)
+			ctrl |= 0x1;
+		else
+			ctrl &= ~0x1;
+		write_wb_reg(reg, i, ctrl);
+	}
+}
+
+/*
+ * Debug exception handlers.
+ */
+static int breakpoint_handler(unsigned long unused, unsigned int esr,
+			      struct pt_regs *regs)
+{
+	int i, step = 0, *kernel_step;
+	u32 ctrl_reg;
+	u64 addr, val;
+	struct perf_event *bp, **slots;
+	struct debug_info *debug_info;
+	struct arch_hw_breakpoint_ctrl ctrl;
+
+	slots = this_cpu_ptr(bp_on_reg);
+	addr = instruction_pointer(regs);
+	debug_info = &current->thread.debug;
+
+	for (i = 0; i < core_num_brps; ++i) {
+		rcu_read_lock();
+
+		bp = slots[i];
+
+		if (bp == NULL)
+			goto unlock;
+
+		/* Check if the breakpoint value matches. */
+		val = read_wb_reg(AARCH64_DBG_REG_BVR, i);
+		if (val != (addr & ~0x3))
+			goto unlock;
+
+		/* Possible match, check the byte address select to confirm. */
+		ctrl_reg = read_wb_reg(AARCH64_DBG_REG_BCR, i);
+		decode_ctrl_reg(ctrl_reg, &ctrl);
+		if (!((1 << (addr & 0x3)) & ctrl.len))
+			goto unlock;
+
+		counter_arch_bp(bp)->trigger = addr;
+		perf_bp_event(bp, regs);
+
+		/* Do we need to handle the stepping? */
+		if (!bp->overflow_handler)
+			step = 1;
+unlock:
+		rcu_read_unlock();
+	}
+
+	if (!step)
+		return 0;
+
+	if (user_mode(regs)) {
+		debug_info->bps_disabled = 1;
+		toggle_bp_registers(AARCH64_DBG_REG_BCR, DBG_ACTIVE_EL0, 0);
+
+		/* If we're already stepping a watchpoint, just return. */
+		if (debug_info->wps_disabled)
+			return 0;
+
+		if (test_thread_flag(TIF_SINGLESTEP))
+			debug_info->suspended_step = 1;
+		else
+			user_enable_single_step(current);
+	} else {
+		toggle_bp_registers(AARCH64_DBG_REG_BCR, DBG_ACTIVE_EL1, 0);
+		kernel_step = this_cpu_ptr(&stepping_kernel_bp);
+
+		if (*kernel_step != ARM_KERNEL_STEP_NONE)
+			return 0;
+
+		if (kernel_active_single_step()) {
+			*kernel_step = ARM_KERNEL_STEP_SUSPEND;
+		} else {
+			*kernel_step = ARM_KERNEL_STEP_ACTIVE;
+			kernel_enable_single_step(regs);
+		}
+	}
+
+	return 0;
+}
+
+static int watchpoint_handler(unsigned long addr, unsigned int esr,
+			      struct pt_regs *regs)
+{
+	int i, step = 0, *kernel_step, access;
+	u32 ctrl_reg;
+	u64 val, alignment_mask;
+	struct perf_event *wp, **slots;
+	struct debug_info *debug_info;
+	struct arch_hw_breakpoint *info;
+	struct arch_hw_breakpoint_ctrl ctrl;
+
+	slots = this_cpu_ptr(wp_on_reg);
+	debug_info = &current->thread.debug;
+
+	for (i = 0; i < core_num_wrps; ++i) {
+		rcu_read_lock();
+
+		wp = slots[i];
+
+		if (wp == NULL)
+			goto unlock;
+
+		info = counter_arch_bp(wp);
+		/* AArch32 watchpoints are either 4 or 8 bytes aligned. */
+		if (is_compat_task()) {
+			if (info->ctrl.len == ARM_BREAKPOINT_LEN_8)
+				alignment_mask = 0x7;
+			else
+				alignment_mask = 0x3;
+		} else {
+			alignment_mask = 0x7;
+		}
+
+		/* Check if the watchpoint value matches. */
+		val = read_wb_reg(AARCH64_DBG_REG_WVR, i);
+		if (val != (addr & ~alignment_mask))
+			goto unlock;
+
+		/* Possible match, check the byte address select to confirm. */
+		ctrl_reg = read_wb_reg(AARCH64_DBG_REG_WCR, i);
+		decode_ctrl_reg(ctrl_reg, &ctrl);
+		if (!((1 << (addr & alignment_mask)) & ctrl.len))
+			goto unlock;
+
+		/*
+		 * Check that the access type matches.
+		 * 0 => load, otherwise => store
+		 */
+		access = (esr & AARCH64_ESR_ACCESS_MASK) ? HW_BREAKPOINT_W :
+			 HW_BREAKPOINT_R;
+		if (!(access & hw_breakpoint_type(wp)))
+			goto unlock;
+
+		info->trigger = addr;
+		perf_bp_event(wp, regs);
+
+		/* Do we need to handle the stepping? */
+		if (!wp->overflow_handler)
+			step = 1;
+
+unlock:
+		rcu_read_unlock();
+	}
+
+	if (!step)
+		return 0;
+
+	/*
+	 * We always disable EL0 watchpoints because the kernel can
+	 * cause these to fire via an unprivileged access.
+	 */
+	toggle_bp_registers(AARCH64_DBG_REG_WCR, DBG_ACTIVE_EL0, 0);
+
+	if (user_mode(regs)) {
+		debug_info->wps_disabled = 1;
+
+		/* If we're already stepping a breakpoint, just return. */
+		if (debug_info->bps_disabled)
+			return 0;
+
+		if (test_thread_flag(TIF_SINGLESTEP))
+			debug_info->suspended_step = 1;
+		else
+			user_enable_single_step(current);
+	} else {
+		toggle_bp_registers(AARCH64_DBG_REG_WCR, DBG_ACTIVE_EL1, 0);
+		kernel_step = this_cpu_ptr(&stepping_kernel_bp);
+
+		if (*kernel_step != ARM_KERNEL_STEP_NONE)
+			return 0;
+
+		if (kernel_active_single_step()) {
+			*kernel_step = ARM_KERNEL_STEP_SUSPEND;
+		} else {
+			*kernel_step = ARM_KERNEL_STEP_ACTIVE;
+			kernel_enable_single_step(regs);
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Handle single-step exception.
+ */
+int reinstall_suspended_bps(struct pt_regs *regs)
+{
+	struct debug_info *debug_info = &current->thread.debug;
+	int handled_exception = 0, *kernel_step;
+
+	kernel_step = this_cpu_ptr(&stepping_kernel_bp);
+
+	/*
+	 * Called from single-step exception handler.
+	 * Return 0 if execution can resume, 1 if a SIGTRAP should be
+	 * reported.
+	 */
+	if (user_mode(regs)) {
+		if (debug_info->bps_disabled) {
+			debug_info->bps_disabled = 0;
+			toggle_bp_registers(AARCH64_DBG_REG_BCR, DBG_ACTIVE_EL0, 1);
+			handled_exception = 1;
+		}
+
+		if (debug_info->wps_disabled) {
+			debug_info->wps_disabled = 0;
+			toggle_bp_registers(AARCH64_DBG_REG_WCR, DBG_ACTIVE_EL0, 1);
+			handled_exception = 1;
+		}
+
+		if (handled_exception) {
+			if (debug_info->suspended_step) {
+				debug_info->suspended_step = 0;
+				/* Allow exception handling to fall-through. */
+				handled_exception = 0;
+			} else {
+				user_disable_single_step(current);
+			}
+		}
+	} else if (*kernel_step != ARM_KERNEL_STEP_NONE) {
+		toggle_bp_registers(AARCH64_DBG_REG_BCR, DBG_ACTIVE_EL1, 1);
+		toggle_bp_registers(AARCH64_DBG_REG_WCR, DBG_ACTIVE_EL1, 1);
+
+		if (!debug_info->wps_disabled)
+			toggle_bp_registers(AARCH64_DBG_REG_WCR, DBG_ACTIVE_EL0, 1);
+
+		if (*kernel_step != ARM_KERNEL_STEP_SUSPEND) {
+			kernel_disable_single_step();
+			handled_exception = 1;
+		} else {
+			handled_exception = 0;
+		}
+
+		*kernel_step = ARM_KERNEL_STEP_NONE;
+	}
+
+	return !handled_exception;
+}
+
+/*
+ * Context-switcher for restoring suspended breakpoints.
+ */
+void hw_breakpoint_thread_switch(struct task_struct *next)
+{
+	/*
+	 *           current        next
+	 * disabled: 0              0     => The usual case, NOTIFY_DONE
+	 *           0              1     => Disable the registers
+	 *           1              0     => Enable the registers
+	 *           1              1     => NOTIFY_DONE. per-task bps will
+	 *                                   get taken care of by perf.
+	 */
+
+	struct debug_info *current_debug_info, *next_debug_info;
+
+	current_debug_info = &current->thread.debug;
+	next_debug_info = &next->thread.debug;
+
+	/* Update breakpoints. */
+	if (current_debug_info->bps_disabled != next_debug_info->bps_disabled)
+		toggle_bp_registers(AARCH64_DBG_REG_BCR,
+				    DBG_ACTIVE_EL0,
+				    !next_debug_info->bps_disabled);
+
+	/* Update watchpoints. */
+	if (current_debug_info->wps_disabled != next_debug_info->wps_disabled)
+		toggle_bp_registers(AARCH64_DBG_REG_WCR,
+				    DBG_ACTIVE_EL0,
+				    !next_debug_info->wps_disabled);
+}
+
+/*
+ * CPU initialisation.
+ */
+static void hw_breakpoint_reset(void *unused)
+{
+	int i;
+	struct perf_event **slots;
+	/*
+	 * When a CPU goes through cold-boot, it does not have any installed
+	 * slot, so it is safe to share the same function for restoring and
+	 * resetting breakpoints; when a CPU is hotplugged in, it goes
+	 * through the slots, which are all empty, hence it just resets control
+	 * and value for debug registers.
+	 * When this function is triggered on warm-boot through a CPU PM
+	 * notifier some slots might be initialized; if so they are
+	 * reprogrammed according to the debug slots content.
+	 */
+	for (slots = this_cpu_ptr(bp_on_reg), i = 0; i < core_num_brps; ++i) {
+		if (slots[i]) {
+			hw_breakpoint_control(slots[i], HW_BREAKPOINT_RESTORE);
+		} else {
+			write_wb_reg(AARCH64_DBG_REG_BCR, i, 0UL);
+			write_wb_reg(AARCH64_DBG_REG_BVR, i, 0UL);
+		}
+	}
+
+	for (slots = this_cpu_ptr(wp_on_reg), i = 0; i < core_num_wrps; ++i) {
+		if (slots[i]) {
+			hw_breakpoint_control(slots[i], HW_BREAKPOINT_RESTORE);
+		} else {
+			write_wb_reg(AARCH64_DBG_REG_WCR, i, 0UL);
+			write_wb_reg(AARCH64_DBG_REG_WVR, i, 0UL);
+		}
+	}
+}
+
+static int hw_breakpoint_reset_notify(struct notifier_block *self,
+						unsigned long action,
+						void *hcpu)
+{
+	int cpu = (long)hcpu;
+	if (action == CPU_ONLINE)
+		smp_call_function_single(cpu, hw_breakpoint_reset, NULL, 1);
+	return NOTIFY_OK;
+}
+
+static struct notifier_block hw_breakpoint_reset_nb = {
+	.notifier_call = hw_breakpoint_reset_notify,
+};
+
+#ifdef CONFIG_ARM64_CPU_SUSPEND
+extern void cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *));
+#else
+static inline void cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *))
+{
+}
+#endif
+
+/*
+ * One-time initialisation.
+ */
+static int __init arch_hw_breakpoint_init(void)
+{
+	core_num_brps = get_num_brps();
+	core_num_wrps = get_num_wrps();
+
+	pr_info("found %d breakpoint and %d watchpoint registers.\n",
+		core_num_brps, core_num_wrps);
+
+	cpu_notifier_register_begin();
+
+	/*
+	 * Reset the breakpoint resources. We assume that a halting
+	 * debugger will leave the world in a nice state for us.
+	 */
+	smp_call_function(hw_breakpoint_reset, NULL, 1);
+	hw_breakpoint_reset(NULL);
+
+	/* Register debug fault handlers. */
+	hook_debug_fault_code(DBG_ESR_EVT_HWBP, breakpoint_handler, SIGTRAP,
+			      TRAP_HWBKPT, "hw-breakpoint handler");
+	hook_debug_fault_code(DBG_ESR_EVT_HWWP, watchpoint_handler, SIGTRAP,
+			      TRAP_HWBKPT, "hw-watchpoint handler");
+
+	/* Register hotplug notifier. */
+	__register_cpu_notifier(&hw_breakpoint_reset_nb);
+
+	cpu_notifier_register_done();
+
+	/* Register cpu_suspend hw breakpoint restore hook */
+	cpu_suspend_set_dbg_restorer(hw_breakpoint_reset);
+
+	return 0;
+}
+arch_initcall(arch_hw_breakpoint_init);
+
+void hw_breakpoint_pmu_read(struct perf_event *bp)
+{
+}
+
+/*
+ * Dummy function to register with die_notifier.
+ */
+int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
+				    unsigned long val, void *data)
+{
+	return NOTIFY_DONE;
+}

arch/arm64/kernel/hyp-stub.S

@@ -0,0 +1,110 @@
+/*
+ * Hypervisor stub
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Author:	Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <linux/irqchip/arm-gic-v3.h>
+
+#include <asm/assembler.h>
+#include <asm/ptrace.h>
+#include <asm/virt.h>
+
+	.text
+	.align 11
+
+ENTRY(__hyp_stub_vectors)
+	ventry	el2_sync_invalid		// Synchronous EL2t
+	ventry	el2_irq_invalid			// IRQ EL2t
+	ventry	el2_fiq_invalid			// FIQ EL2t
+	ventry	el2_error_invalid		// Error EL2t
+
+	ventry	el2_sync_invalid		// Synchronous EL2h
+	ventry	el2_irq_invalid			// IRQ EL2h
+	ventry	el2_fiq_invalid			// FIQ EL2h
+	ventry	el2_error_invalid		// Error EL2h
+
+	ventry	el1_sync			// Synchronous 64-bit EL1
+	ventry	el1_irq_invalid			// IRQ 64-bit EL1
+	ventry	el1_fiq_invalid			// FIQ 64-bit EL1
+	ventry	el1_error_invalid		// Error 64-bit EL1
+
+	ventry	el1_sync_invalid		// Synchronous 32-bit EL1
+	ventry	el1_irq_invalid			// IRQ 32-bit EL1
+	ventry	el1_fiq_invalid			// FIQ 32-bit EL1
+	ventry	el1_error_invalid		// Error 32-bit EL1
+ENDPROC(__hyp_stub_vectors)
+
+	.align 11
+
+el1_sync:
+	mrs	x1, esr_el2
+	lsr	x1, x1, #26
+	cmp	x1, #0x16
+	b.ne	2f				// Not an HVC trap
+	cbz	x0, 1f
+	msr	vbar_el2, x0			// Set vbar_el2
+	b	2f
+1:	mrs	x0, vbar_el2			// Return vbar_el2
+2:	eret
+ENDPROC(el1_sync)
+
+.macro invalid_vector	label
+\label:
+	b \label
+ENDPROC(\label)
+.endm
+
+	invalid_vector	el2_sync_invalid
+	invalid_vector	el2_irq_invalid
+	invalid_vector	el2_fiq_invalid
+	invalid_vector	el2_error_invalid
+	invalid_vector	el1_sync_invalid
+	invalid_vector	el1_irq_invalid
+	invalid_vector	el1_fiq_invalid
+	invalid_vector	el1_error_invalid
+
+/*
+ * __hyp_set_vectors: Call this after boot to set the initial hypervisor
+ * vectors as part of hypervisor installation.  On an SMP system, this should
+ * be called on each CPU.
+ *
+ * x0 must be the physical address of the new vector table, and must be
+ * 2KB aligned.
+ *
+ * Before calling this, you must check that the stub hypervisor is installed
+ * everywhere, by waiting for any secondary CPUs to be brought up and then
+ * checking that is_hyp_mode_available() is true.
+ *
+ * If not, there is a pre-existing hypervisor, some CPUs failed to boot, or
+ * something else went wrong... in such cases, trying to install a new
+ * hypervisor is unlikely to work as desired.
+ *
+ * When you call into your shiny new hypervisor, sp_el2 will contain junk,
+ * so you will need to set that to something sensible at the new hypervisor's
+ * initialisation entry point.
+ */
+
+ENTRY(__hyp_get_vectors)
+	mov	x0, xzr
+	// fall through
+ENTRY(__hyp_set_vectors)
+	hvc	#0
+	ret
+ENDPROC(__hyp_get_vectors)
+ENDPROC(__hyp_set_vectors)

arch/arm64/kernel/image.h

@@ -0,0 +1,62 @@
+/*
+ * Linker script macros to generate Image header fields.
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_IMAGE_H
+#define __ASM_IMAGE_H
+
+#ifndef LINKER_SCRIPT
+#error This file should only be included in vmlinux.lds.S
+#endif
+
+/*
+ * There aren't any ELF relocations we can use to endian-swap values known only
+ * at link time (e.g. the subtraction of two symbol addresses), so we must get
+ * the linker to endian-swap certain values before emitting them.
+ */
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define DATA_LE64(data)					\
+	((((data) & 0x00000000000000ff) << 56) |	\
+	 (((data) & 0x000000000000ff00) << 40) |	\
+	 (((data) & 0x0000000000ff0000) << 24) |	\
+	 (((data) & 0x00000000ff000000) << 8)  |	\
+	 (((data) & 0x000000ff00000000) >> 8)  |	\
+	 (((data) & 0x0000ff0000000000) >> 24) |	\
+	 (((data) & 0x00ff000000000000) >> 40) |	\
+	 (((data) & 0xff00000000000000) >> 56))
+#else
+#define DATA_LE64(data) ((data) & 0xffffffffffffffff)
+#endif
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define __HEAD_FLAG_BE	1
+#else
+#define __HEAD_FLAG_BE	0
+#endif
+
+#define __HEAD_FLAGS	(__HEAD_FLAG_BE << 0)
+
+/*
+ * These will output as part of the Image header, which should be little-endian
+ * regardless of the endianness of the kernel. While constant values could be
+ * endian swapped in head.S, all are done here for consistency.
+ */
+#define HEAD_SYMBOLS						\
+	_kernel_size_le		= DATA_LE64(_end - _text);	\
+	_kernel_offset_le	= DATA_LE64(TEXT_OFFSET);	\
+	_kernel_flags_le	= DATA_LE64(__HEAD_FLAGS);
+
+#endif /* __ASM_IMAGE_H */

arch/arm64/kernel/insn.c

@@ -0,0 +1,988 @@
+/*
+ * Copyright (C) 2013 Huawei Ltd.
+ * Author: Jiang Liu <liuj97@gmail.com>
+ *
+ * Copyright (C) 2014 Zi Shen Lim <zlim.lnx@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/bitops.h>
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/stop_machine.h>
+#include <linux/uaccess.h>
+
+#include <asm/cacheflush.h>
+#include <asm/debug-monitors.h>
+#include <asm/insn.h>
+
+#define AARCH64_INSN_SF_BIT	BIT(31)
+#define AARCH64_INSN_N_BIT	BIT(22)
+
+static int aarch64_insn_encoding_class[] = {
+	AARCH64_INSN_CLS_UNKNOWN,
+	AARCH64_INSN_CLS_UNKNOWN,
+	AARCH64_INSN_CLS_UNKNOWN,
+	AARCH64_INSN_CLS_UNKNOWN,
+	AARCH64_INSN_CLS_LDST,
+	AARCH64_INSN_CLS_DP_REG,
+	AARCH64_INSN_CLS_LDST,
+	AARCH64_INSN_CLS_DP_FPSIMD,
+	AARCH64_INSN_CLS_DP_IMM,
+	AARCH64_INSN_CLS_DP_IMM,
+	AARCH64_INSN_CLS_BR_SYS,
+	AARCH64_INSN_CLS_BR_SYS,
+	AARCH64_INSN_CLS_LDST,
+	AARCH64_INSN_CLS_DP_REG,
+	AARCH64_INSN_CLS_LDST,
+	AARCH64_INSN_CLS_DP_FPSIMD,
+};
+
+enum aarch64_insn_encoding_class __kprobes aarch64_get_insn_class(u32 insn)
+{
+	return aarch64_insn_encoding_class[(insn >> 25) & 0xf];
+}
+
+/* NOP is an alias of HINT */
+bool __kprobes aarch64_insn_is_nop(u32 insn)
+{
+	if (!aarch64_insn_is_hint(insn))
+		return false;
+
+	switch (insn & 0xFE0) {
+	case AARCH64_INSN_HINT_YIELD:
+	case AARCH64_INSN_HINT_WFE:
+	case AARCH64_INSN_HINT_WFI:
+	case AARCH64_INSN_HINT_SEV:
+	case AARCH64_INSN_HINT_SEVL:
+		return false;
+	default:
+		return true;
+	}
+}
+
+/*
+ * In ARMv8-A, A64 instructions have a fixed length of 32 bits and are always
+ * little-endian.
+ */
+int __kprobes aarch64_insn_read(void *addr, u32 *insnp)
+{
+	int ret;
+	u32 val;
+
+	ret = probe_kernel_read(&val, addr, AARCH64_INSN_SIZE);
+	if (!ret)
+		*insnp = le32_to_cpu(val);
+
+	return ret;
+}
+
+int __kprobes aarch64_insn_write(void *addr, u32 insn)
+{
+	insn = cpu_to_le32(insn);
+	return probe_kernel_write(addr, &insn, AARCH64_INSN_SIZE);
+}
+
+static bool __kprobes __aarch64_insn_hotpatch_safe(u32 insn)
+{
+	if (aarch64_get_insn_class(insn) != AARCH64_INSN_CLS_BR_SYS)
+		return false;
+
+	return	aarch64_insn_is_b(insn) ||
+		aarch64_insn_is_bl(insn) ||
+		aarch64_insn_is_svc(insn) ||
+		aarch64_insn_is_hvc(insn) ||
+		aarch64_insn_is_smc(insn) ||
+		aarch64_insn_is_brk(insn) ||
+		aarch64_insn_is_nop(insn);
+}
+
+/*
+ * ARM Architecture Reference Manual for ARMv8 Profile-A, Issue A.a
+ * Section B2.6.5 "Concurrent modification and execution of instructions":
+ * Concurrent modification and execution of instructions can lead to the
+ * resulting instruction performing any behavior that can be achieved by
+ * executing any sequence of instructions that can be executed from the
+ * same Exception level, except where the instruction before modification
+ * and the instruction after modification is a B, BL, NOP, BKPT, SVC, HVC,
+ * or SMC instruction.
+ */
+bool __kprobes aarch64_insn_hotpatch_safe(u32 old_insn, u32 new_insn)
+{
+	return __aarch64_insn_hotpatch_safe(old_insn) &&
+	       __aarch64_insn_hotpatch_safe(new_insn);
+}
+
+int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn)
+{
+	u32 *tp = addr;
+	int ret;
+
+	/* A64 instructions must be word aligned */
+	if ((uintptr_t)tp & 0x3)
+		return -EINVAL;
+
+	ret = aarch64_insn_write(tp, insn);
+	if (ret == 0)
+		flush_icache_range((uintptr_t)tp,
+				   (uintptr_t)tp + AARCH64_INSN_SIZE);
+
+	return ret;
+}
+
+struct aarch64_insn_patch {
+	void		**text_addrs;
+	u32		*new_insns;
+	int		insn_cnt;
+	atomic_t	cpu_count;
+};
+
+static int __kprobes aarch64_insn_patch_text_cb(void *arg)
+{
+	int i, ret = 0;
+	struct aarch64_insn_patch *pp = arg;
+
+	/* The first CPU becomes master */
+	if (atomic_inc_return(&pp->cpu_count) == 1) {
+		for (i = 0; ret == 0 && i < pp->insn_cnt; i++)
+			ret = aarch64_insn_patch_text_nosync(pp->text_addrs[i],
+							     pp->new_insns[i]);
+		/*
+		 * aarch64_insn_patch_text_nosync() calls flush_icache_range(),
+		 * which ends with "dsb; isb" pair guaranteeing global
+		 * visibility.
+		 */
+		/* Notify other processors with an additional increment. */
+		atomic_inc(&pp->cpu_count);
+	} else {
+		while (atomic_read(&pp->cpu_count) <= num_online_cpus())
+			cpu_relax();
+		isb();
+	}
+
+	return ret;
+}
+
+int __kprobes aarch64_insn_patch_text_sync(void *addrs[], u32 insns[], int cnt)
+{
+	struct aarch64_insn_patch patch = {
+		.text_addrs = addrs,
+		.new_insns = insns,
+		.insn_cnt = cnt,
+		.cpu_count = ATOMIC_INIT(0),
+	};
+
+	if (cnt <= 0)
+		return -EINVAL;
+
+	return stop_machine(aarch64_insn_patch_text_cb, &patch,
+			    cpu_online_mask);
+}
+
+int __kprobes aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt)
+{
+	int ret;
+	u32 insn;
+
+	/* Unsafe to patch multiple instructions without synchronizaiton */
+	if (cnt == 1) {
+		ret = aarch64_insn_read(addrs[0], &insn);
+		if (ret)
+			return ret;
+
+		if (aarch64_insn_hotpatch_safe(insn, insns[0])) {
+			/*
+			 * ARMv8 architecture doesn't guarantee all CPUs see
+			 * the new instruction after returning from function
+			 * aarch64_insn_patch_text_nosync(). So send IPIs to
+			 * all other CPUs to achieve instruction
+			 * synchronization.
+			 */
+			ret = aarch64_insn_patch_text_nosync(addrs[0], insns[0]);
+			kick_all_cpus_sync();
+			return ret;
+		}
+	}
+
+	return aarch64_insn_patch_text_sync(addrs, insns, cnt);
+}
+
+u32 __kprobes aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,
+				  u32 insn, u64 imm)
+{
+	u32 immlo, immhi, lomask, himask, mask;
+	int shift;
+
+	switch (type) {
+	case AARCH64_INSN_IMM_ADR:
+		lomask = 0x3;
+		himask = 0x7ffff;
+		immlo = imm & lomask;
+		imm >>= 2;
+		immhi = imm & himask;
+		imm = (immlo << 24) | (immhi);
+		mask = (lomask << 24) | (himask);
+		shift = 5;
+		break;
+	case AARCH64_INSN_IMM_26:
+		mask = BIT(26) - 1;
+		shift = 0;
+		break;
+	case AARCH64_INSN_IMM_19:
+		mask = BIT(19) - 1;
+		shift = 5;
+		break;
+	case AARCH64_INSN_IMM_16:
+		mask = BIT(16) - 1;
+		shift = 5;
+		break;
+	case AARCH64_INSN_IMM_14:
+		mask = BIT(14) - 1;
+		shift = 5;
+		break;
+	case AARCH64_INSN_IMM_12:
+		mask = BIT(12) - 1;
+		shift = 10;
+		break;
+	case AARCH64_INSN_IMM_9:
+		mask = BIT(9) - 1;
+		shift = 12;
+		break;
+	case AARCH64_INSN_IMM_7:
+		mask = BIT(7) - 1;
+		shift = 15;
+		break;
+	case AARCH64_INSN_IMM_6:
+	case AARCH64_INSN_IMM_S:
+		mask = BIT(6) - 1;
+		shift = 10;
+		break;
+	case AARCH64_INSN_IMM_R:
+		mask = BIT(6) - 1;
+		shift = 16;
+		break;
+	default:
+		pr_err("aarch64_insn_encode_immediate: unknown immediate encoding %d\n",
+			type);
+		return 0;
+	}
+
+	/* Update the immediate field. */
+	insn &= ~(mask << shift);
+	insn |= (imm & mask) << shift;
+
+	return insn;
+}
+
+static u32 aarch64_insn_encode_register(enum aarch64_insn_register_type type,
+					u32 insn,
+					enum aarch64_insn_register reg)
+{
+	int shift;
+
+	if (reg < AARCH64_INSN_REG_0 || reg > AARCH64_INSN_REG_SP) {
+		pr_err("%s: unknown register encoding %d\n", __func__, reg);
+		return 0;
+	}
+
+	switch (type) {
+	case AARCH64_INSN_REGTYPE_RT:
+	case AARCH64_INSN_REGTYPE_RD:
+		shift = 0;
+		break;
+	case AARCH64_INSN_REGTYPE_RN:
+		shift = 5;
+		break;
+	case AARCH64_INSN_REGTYPE_RT2:
+	case AARCH64_INSN_REGTYPE_RA:
+		shift = 10;
+		break;
+	case AARCH64_INSN_REGTYPE_RM:
+		shift = 16;
+		break;
+	default:
+		pr_err("%s: unknown register type encoding %d\n", __func__,
+		       type);
+		return 0;
+	}
+
+	insn &= ~(GENMASK(4, 0) << shift);
+	insn |= reg << shift;
+
+	return insn;
+}
+
+static u32 aarch64_insn_encode_ldst_size(enum aarch64_insn_size_type type,
+					 u32 insn)
+{
+	u32 size;
+
+	switch (type) {
+	case AARCH64_INSN_SIZE_8:
+		size = 0;
+		break;
+	case AARCH64_INSN_SIZE_16:
+		size = 1;
+		break;
+	case AARCH64_INSN_SIZE_32:
+		size = 2;
+		break;
+	case AARCH64_INSN_SIZE_64:
+		size = 3;
+		break;
+	default:
+		pr_err("%s: unknown size encoding %d\n", __func__, type);
+		return 0;
+	}
+
+	insn &= ~GENMASK(31, 30);
+	insn |= size << 30;
+
+	return insn;
+}
+
+static inline long branch_imm_common(unsigned long pc, unsigned long addr,
+				     long range)
+{
+	long offset;
+
+	/*
+	 * PC: A 64-bit Program Counter holding the address of the current
+	 * instruction. A64 instructions must be word-aligned.
+	 */
+	BUG_ON((pc & 0x3) || (addr & 0x3));
+
+	offset = ((long)addr - (long)pc);
+	BUG_ON(offset < -range || offset >= range);
+
+	return offset;
+}
+
+u32 __kprobes aarch64_insn_gen_branch_imm(unsigned long pc, unsigned long addr,
+					  enum aarch64_insn_branch_type type)
+{
+	u32 insn;
+	long offset;
+
+	/*
+	 * B/BL support [-128M, 128M) offset
+	 * ARM64 virtual address arrangement guarantees all kernel and module
+	 * texts are within +/-128M.
+	 */
+	offset = branch_imm_common(pc, addr, SZ_128M);
+
+	switch (type) {
+	case AARCH64_INSN_BRANCH_LINK:
+		insn = aarch64_insn_get_bl_value();
+		break;
+	case AARCH64_INSN_BRANCH_NOLINK:
+		insn = aarch64_insn_get_b_value();
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_26, insn,
+					     offset >> 2);
+}
+
+u32 aarch64_insn_gen_comp_branch_imm(unsigned long pc, unsigned long addr,
+				     enum aarch64_insn_register reg,
+				     enum aarch64_insn_variant variant,
+				     enum aarch64_insn_branch_type type)
+{
+	u32 insn;
+	long offset;
+
+	offset = branch_imm_common(pc, addr, SZ_1M);
+
+	switch (type) {
+	case AARCH64_INSN_BRANCH_COMP_ZERO:
+		insn = aarch64_insn_get_cbz_value();
+		break;
+	case AARCH64_INSN_BRANCH_COMP_NONZERO:
+		insn = aarch64_insn_get_cbnz_value();
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	switch (variant) {
+	case AARCH64_INSN_VARIANT_32BIT:
+		break;
+	case AARCH64_INSN_VARIANT_64BIT:
+		insn |= AARCH64_INSN_SF_BIT;
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn, reg);
+
+	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
+					     offset >> 2);
+}
+
+u32 aarch64_insn_gen_cond_branch_imm(unsigned long pc, unsigned long addr,
+				     enum aarch64_insn_condition cond)
+{
+	u32 insn;
+	long offset;
+
+	offset = branch_imm_common(pc, addr, SZ_1M);
+
+	insn = aarch64_insn_get_bcond_value();
+
+	BUG_ON(cond < AARCH64_INSN_COND_EQ || cond > AARCH64_INSN_COND_AL);
+	insn |= cond;
+
+	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
+					     offset >> 2);
+}
+
+u32 __kprobes aarch64_insn_gen_hint(enum aarch64_insn_hint_op op)
+{
+	return aarch64_insn_get_hint_value() | op;
+}
+
+u32 __kprobes aarch64_insn_gen_nop(void)
+{
+	return aarch64_insn_gen_hint(AARCH64_INSN_HINT_NOP);
+}
+
+u32 aarch64_insn_gen_branch_reg(enum aarch64_insn_register reg,
+				enum aarch64_insn_branch_type type)
+{
+	u32 insn;
+
+	switch (type) {
+	case AARCH64_INSN_BRANCH_NOLINK:
+		insn = aarch64_insn_get_br_value();
+		break;
+	case AARCH64_INSN_BRANCH_LINK:
+		insn = aarch64_insn_get_blr_value();
+		break;
+	case AARCH64_INSN_BRANCH_RETURN:
+		insn = aarch64_insn_get_ret_value();
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, reg);
+}
+
+u32 aarch64_insn_gen_load_store_reg(enum aarch64_insn_register reg,
+				    enum aarch64_insn_register base,
+				    enum aarch64_insn_register offset,
+				    enum aarch64_insn_size_type size,
+				    enum aarch64_insn_ldst_type type)
+{
+	u32 insn;
+
+	switch (type) {
+	case AARCH64_INSN_LDST_LOAD_REG_OFFSET:
+		insn = aarch64_insn_get_ldr_reg_value();
+		break;
+	case AARCH64_INSN_LDST_STORE_REG_OFFSET:
+		insn = aarch64_insn_get_str_reg_value();
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	insn = aarch64_insn_encode_ldst_size(size, insn);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn, reg);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
+					    base);
+
+	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn,
+					    offset);
+}
+
+u32 aarch64_insn_gen_load_store_pair(enum aarch64_insn_register reg1,
+				     enum aarch64_insn_register reg2,
+				     enum aarch64_insn_register base,
+				     int offset,
+				     enum aarch64_insn_variant variant,
+				     enum aarch64_insn_ldst_type type)
+{
+	u32 insn;
+	int shift;
+
+	switch (type) {
+	case AARCH64_INSN_LDST_LOAD_PAIR_PRE_INDEX:
+		insn = aarch64_insn_get_ldp_pre_value();
+		break;
+	case AARCH64_INSN_LDST_STORE_PAIR_PRE_INDEX:
+		insn = aarch64_insn_get_stp_pre_value();
+		break;
+	case AARCH64_INSN_LDST_LOAD_PAIR_POST_INDEX:
+		insn = aarch64_insn_get_ldp_post_value();
+		break;
+	case AARCH64_INSN_LDST_STORE_PAIR_POST_INDEX:
+		insn = aarch64_insn_get_stp_post_value();
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	switch (variant) {
+	case AARCH64_INSN_VARIANT_32BIT:
+		/* offset must be multiples of 4 in the range [-256, 252] */
+		BUG_ON(offset & 0x3);
+		BUG_ON(offset < -256 || offset > 252);
+		shift = 2;
+		break;
+	case AARCH64_INSN_VARIANT_64BIT:
+		/* offset must be multiples of 8 in the range [-512, 504] */
+		BUG_ON(offset & 0x7);
+		BUG_ON(offset < -512 || offset > 504);
+		shift = 3;
+		insn |= AARCH64_INSN_SF_BIT;
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn,
+					    reg1);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT2, insn,
+					    reg2);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
+					    base);
+
+	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_7, insn,
+					     offset >> shift);
+}
+
+u32 aarch64_insn_gen_add_sub_imm(enum aarch64_insn_register dst,
+				 enum aarch64_insn_register src,
+				 int imm, enum aarch64_insn_variant variant,
+				 enum aarch64_insn_adsb_type type)
+{
+	u32 insn;
+
+	switch (type) {
+	case AARCH64_INSN_ADSB_ADD:
+		insn = aarch64_insn_get_add_imm_value();
+		break;
+	case AARCH64_INSN_ADSB_SUB:
+		insn = aarch64_insn_get_sub_imm_value();
+		break;
+	case AARCH64_INSN_ADSB_ADD_SETFLAGS:
+		insn = aarch64_insn_get_adds_imm_value();
+		break;
+	case AARCH64_INSN_ADSB_SUB_SETFLAGS:
+		insn = aarch64_insn_get_subs_imm_value();
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	switch (variant) {
+	case AARCH64_INSN_VARIANT_32BIT:
+		break;
+	case AARCH64_INSN_VARIANT_64BIT:
+		insn |= AARCH64_INSN_SF_BIT;
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	BUG_ON(imm & ~(SZ_4K - 1));
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
+
+	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_12, insn, imm);
+}
+
+u32 aarch64_insn_gen_bitfield(enum aarch64_insn_register dst,
+			      enum aarch64_insn_register src,
+			      int immr, int imms,
+			      enum aarch64_insn_variant variant,
+			      enum aarch64_insn_bitfield_type type)
+{
+	u32 insn;
+	u32 mask;
+
+	switch (type) {
+	case AARCH64_INSN_BITFIELD_MOVE:
+		insn = aarch64_insn_get_bfm_value();
+		break;
+	case AARCH64_INSN_BITFIELD_MOVE_UNSIGNED:
+		insn = aarch64_insn_get_ubfm_value();
+		break;
+	case AARCH64_INSN_BITFIELD_MOVE_SIGNED:
+		insn = aarch64_insn_get_sbfm_value();
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	switch (variant) {
+	case AARCH64_INSN_VARIANT_32BIT:
+		mask = GENMASK(4, 0);
+		break;
+	case AARCH64_INSN_VARIANT_64BIT:
+		insn |= AARCH64_INSN_SF_BIT | AARCH64_INSN_N_BIT;
+		mask = GENMASK(5, 0);
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	BUG_ON(immr & ~mask);
+	BUG_ON(imms & ~mask);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
+
+	insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_R, insn, immr);
+
+	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_S, insn, imms);
+}
+
+u32 aarch64_insn_gen_movewide(enum aarch64_insn_register dst,
+			      int imm, int shift,
+			      enum aarch64_insn_variant variant,
+			      enum aarch64_insn_movewide_type type)
+{
+	u32 insn;
+
+	switch (type) {
+	case AARCH64_INSN_MOVEWIDE_ZERO:
+		insn = aarch64_insn_get_movz_value();
+		break;
+	case AARCH64_INSN_MOVEWIDE_KEEP:
+		insn = aarch64_insn_get_movk_value();
+		break;
+	case AARCH64_INSN_MOVEWIDE_INVERSE:
+		insn = aarch64_insn_get_movn_value();
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	BUG_ON(imm & ~(SZ_64K - 1));
+
+	switch (variant) {
+	case AARCH64_INSN_VARIANT_32BIT:
+		BUG_ON(shift != 0 && shift != 16);
+		break;
+	case AARCH64_INSN_VARIANT_64BIT:
+		insn |= AARCH64_INSN_SF_BIT;
+		BUG_ON(shift != 0 && shift != 16 && shift != 32 &&
+		       shift != 48);
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	insn |= (shift >> 4) << 21;
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
+
+	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_16, insn, imm);
+}
+
+u32 aarch64_insn_gen_add_sub_shifted_reg(enum aarch64_insn_register dst,
+					 enum aarch64_insn_register src,
+					 enum aarch64_insn_register reg,
+					 int shift,
+					 enum aarch64_insn_variant variant,
+					 enum aarch64_insn_adsb_type type)
+{
+	u32 insn;
+
+	switch (type) {
+	case AARCH64_INSN_ADSB_ADD:
+		insn = aarch64_insn_get_add_value();
+		break;
+	case AARCH64_INSN_ADSB_SUB:
+		insn = aarch64_insn_get_sub_value();
+		break;
+	case AARCH64_INSN_ADSB_ADD_SETFLAGS:
+		insn = aarch64_insn_get_adds_value();
+		break;
+	case AARCH64_INSN_ADSB_SUB_SETFLAGS:
+		insn = aarch64_insn_get_subs_value();
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	switch (variant) {
+	case AARCH64_INSN_VARIANT_32BIT:
+		BUG_ON(shift & ~(SZ_32 - 1));
+		break;
+	case AARCH64_INSN_VARIANT_64BIT:
+		insn |= AARCH64_INSN_SF_BIT;
+		BUG_ON(shift & ~(SZ_64 - 1));
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
+
+	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_6, insn, shift);
+}
+
+u32 aarch64_insn_gen_data1(enum aarch64_insn_register dst,
+			   enum aarch64_insn_register src,
+			   enum aarch64_insn_variant variant,
+			   enum aarch64_insn_data1_type type)
+{
+	u32 insn;
+
+	switch (type) {
+	case AARCH64_INSN_DATA1_REVERSE_16:
+		insn = aarch64_insn_get_rev16_value();
+		break;
+	case AARCH64_INSN_DATA1_REVERSE_32:
+		insn = aarch64_insn_get_rev32_value();
+		break;
+	case AARCH64_INSN_DATA1_REVERSE_64:
+		BUG_ON(variant != AARCH64_INSN_VARIANT_64BIT);
+		insn = aarch64_insn_get_rev64_value();
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	switch (variant) {
+	case AARCH64_INSN_VARIANT_32BIT:
+		break;
+	case AARCH64_INSN_VARIANT_64BIT:
+		insn |= AARCH64_INSN_SF_BIT;
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
+
+	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
+}
+
+u32 aarch64_insn_gen_data2(enum aarch64_insn_register dst,
+			   enum aarch64_insn_register src,
+			   enum aarch64_insn_register reg,
+			   enum aarch64_insn_variant variant,
+			   enum aarch64_insn_data2_type type)
+{
+	u32 insn;
+
+	switch (type) {
+	case AARCH64_INSN_DATA2_UDIV:
+		insn = aarch64_insn_get_udiv_value();
+		break;
+	case AARCH64_INSN_DATA2_SDIV:
+		insn = aarch64_insn_get_sdiv_value();
+		break;
+	case AARCH64_INSN_DATA2_LSLV:
+		insn = aarch64_insn_get_lslv_value();
+		break;
+	case AARCH64_INSN_DATA2_LSRV:
+		insn = aarch64_insn_get_lsrv_value();
+		break;
+	case AARCH64_INSN_DATA2_ASRV:
+		insn = aarch64_insn_get_asrv_value();
+		break;
+	case AARCH64_INSN_DATA2_RORV:
+		insn = aarch64_insn_get_rorv_value();
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	switch (variant) {
+	case AARCH64_INSN_VARIANT_32BIT:
+		break;
+	case AARCH64_INSN_VARIANT_64BIT:
+		insn |= AARCH64_INSN_SF_BIT;
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
+
+	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
+}
+
+u32 aarch64_insn_gen_data3(enum aarch64_insn_register dst,
+			   enum aarch64_insn_register src,
+			   enum aarch64_insn_register reg1,
+			   enum aarch64_insn_register reg2,
+			   enum aarch64_insn_variant variant,
+			   enum aarch64_insn_data3_type type)
+{
+	u32 insn;
+
+	switch (type) {
+	case AARCH64_INSN_DATA3_MADD:
+		insn = aarch64_insn_get_madd_value();
+		break;
+	case AARCH64_INSN_DATA3_MSUB:
+		insn = aarch64_insn_get_msub_value();
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	switch (variant) {
+	case AARCH64_INSN_VARIANT_32BIT:
+		break;
+	case AARCH64_INSN_VARIANT_64BIT:
+		insn |= AARCH64_INSN_SF_BIT;
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RA, insn, src);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
+					    reg1);
+
+	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn,
+					    reg2);
+}
+
+u32 aarch64_insn_gen_logical_shifted_reg(enum aarch64_insn_register dst,
+					 enum aarch64_insn_register src,
+					 enum aarch64_insn_register reg,
+					 int shift,
+					 enum aarch64_insn_variant variant,
+					 enum aarch64_insn_logic_type type)
+{
+	u32 insn;
+
+	switch (type) {
+	case AARCH64_INSN_LOGIC_AND:
+		insn = aarch64_insn_get_and_value();
+		break;
+	case AARCH64_INSN_LOGIC_BIC:
+		insn = aarch64_insn_get_bic_value();
+		break;
+	case AARCH64_INSN_LOGIC_ORR:
+		insn = aarch64_insn_get_orr_value();
+		break;
+	case AARCH64_INSN_LOGIC_ORN:
+		insn = aarch64_insn_get_orn_value();
+		break;
+	case AARCH64_INSN_LOGIC_EOR:
+		insn = aarch64_insn_get_eor_value();
+		break;
+	case AARCH64_INSN_LOGIC_EON:
+		insn = aarch64_insn_get_eon_value();
+		break;
+	case AARCH64_INSN_LOGIC_AND_SETFLAGS:
+		insn = aarch64_insn_get_ands_value();
+		break;
+	case AARCH64_INSN_LOGIC_BIC_SETFLAGS:
+		insn = aarch64_insn_get_bics_value();
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+	switch (variant) {
+	case AARCH64_INSN_VARIANT_32BIT:
+		BUG_ON(shift & ~(SZ_32 - 1));
+		break;
+	case AARCH64_INSN_VARIANT_64BIT:
+		insn |= AARCH64_INSN_SF_BIT;
+		BUG_ON(shift & ~(SZ_64 - 1));
+		break;
+	default:
+		BUG_ON(1);
+		return AARCH64_BREAK_FAULT;
+	}
+
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
+
+	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
+
+	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_6, insn, shift);
+}
+
+bool aarch32_insn_is_wide(u32 insn)
+{
+	return insn >= 0xe800;
+}
+
+/*
+ * Macros/defines for extracting register numbers from instruction.
+ */
+u32 aarch32_insn_extract_reg_num(u32 insn, int offset)
+{
+	return (insn & (0xf << offset)) >> offset;
+}
+
+#define OPC2_MASK	0x7
+#define OPC2_OFFSET	5
+u32 aarch32_insn_mcr_extract_opc2(u32 insn)
+{
+	return (insn & (OPC2_MASK << OPC2_OFFSET)) >> OPC2_OFFSET;
+}
+
+#define CRM_MASK	0xf
+u32 aarch32_insn_mcr_extract_crm(u32 insn)
+{
+	return insn & CRM_MASK;
+}

arch/arm64/kernel/io.c

@@ -0,0 +1,64 @@
+/*
+ * Based on arch/arm/kernel/io.c
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/io.h>
+
+/*
+ * Copy data from IO memory space to "real" memory space.
+ */
+void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
+{
+	unsigned char *t = to;
+	while (count) {
+		count--;
+		*t = readb(from);
+		t++;
+		from++;
+	}
+}
+EXPORT_SYMBOL(__memcpy_fromio);
+
+/*
+ * Copy data from "real" memory space to IO memory space.
+ */
+void __memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
+{
+	const unsigned char *f = from;
+	while (count) {
+		count--;
+		writeb(*f, to);
+		f++;
+		to++;
+	}
+}
+EXPORT_SYMBOL(__memcpy_toio);
+
+/*
+ * "memset" on IO memory space.
+ */
+void __memset_io(volatile void __iomem *dst, int c, size_t count)
+{
+	while (count) {
+		count--;
+		writeb(c, dst);
+		dst++;
+	}
+}
+EXPORT_SYMBOL(__memset_io);

arch/arm64/kernel/irq.c

@@ -0,0 +1,121 @@
+/*
+ * Based on arch/arm/kernel/irq.c
+ *
+ * Copyright (C) 1992 Linus Torvalds
+ * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
+ * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
+ * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
+ * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kernel_stat.h>
+#include <linux/irq.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/irqchip.h>
+#include <linux/seq_file.h>
+#include <linux/ratelimit.h>
+
+unsigned long irq_err_count;
+
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+#ifdef CONFIG_SMP
+	show_ipi_list(p, prec);
+#endif
+	seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
+	return 0;
+}
+
+void (*handle_arch_irq)(struct pt_regs *) = NULL;
+
+void __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
+{
+	if (handle_arch_irq)
+		return;
+
+	handle_arch_irq = handle_irq;
+}
+
+void __init init_IRQ(void)
+{
+	irqchip_init();
+	if (!handle_arch_irq)
+		panic("No interrupt controller found.");
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static bool migrate_one_irq(struct irq_desc *desc)
+{
+	struct irq_data *d = irq_desc_get_irq_data(desc);
+	const struct cpumask *affinity = d->affinity;
+	struct irq_chip *c;
+	bool ret = false;
+
+	/*
+	 * If this is a per-CPU interrupt, or the affinity does not
+	 * include this CPU, then we have nothing to do.
+	 */
+	if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
+		return false;
+
+	if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
+		affinity = cpu_online_mask;
+		ret = true;
+	} else if (unlikely(d->state_use_accessors & IRQD_GIC_MULTI_TARGET)) {
+		return false;
+	}
+
+	c = irq_data_get_irq_chip(d);
+	if (!c->irq_set_affinity)
+		pr_debug("IRQ%u: unable to set affinity\n", d->irq);
+	else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret)
+		cpumask_copy(d->affinity, affinity);
+
+	return ret;
+}
+
+/*
+ * The current CPU has been marked offline.  Migrate IRQs off this CPU.
+ * If the affinity settings do not allow other CPUs, force them onto any
+ * available CPU.
+ *
+ * Note: we must iterate over all IRQs, whether they have an attached
+ * action structure or not, as we need to get chained interrupts too.
+ */
+void migrate_irqs(void)
+{
+	unsigned int i;
+	struct irq_desc *desc;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	for_each_irq_desc(i, desc) {
+		bool affinity_broken;
+
+		raw_spin_lock(&desc->lock);
+		affinity_broken = migrate_one_irq(desc);
+		raw_spin_unlock(&desc->lock);
+
+		if (affinity_broken)
+			pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n",
+					    i, smp_processor_id());
+	}
+
+	local_irq_restore(flags);
+}
+#endif /* CONFIG_HOTPLUG_CPU */

arch/arm64/kernel/jump_label.c

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2013 Huawei Ltd.
+ * Author: Jiang Liu <liuj97@gmail.com>
+ *
+ * Based on arch/arm/kernel/jump_label.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/kernel.h>
+#include <linux/jump_label.h>
+#include <asm/insn.h>
+
+#ifdef HAVE_JUMP_LABEL
+
+void arch_jump_label_transform(struct jump_entry *entry,
+			       enum jump_label_type type)
+{
+	void *addr = (void *)entry->code;
+	u32 insn;
+
+	if (type == JUMP_LABEL_ENABLE) {
+		insn = aarch64_insn_gen_branch_imm(entry->code,
+						   entry->target,
+						   AARCH64_INSN_BRANCH_NOLINK);
+	} else {
+		insn = aarch64_insn_gen_nop();
+	}
+
+	aarch64_insn_patch_text(&addr, &insn, 1);
+}
+
+void arch_jump_label_transform_static(struct jump_entry *entry,
+				      enum jump_label_type type)
+{
+	/*
+	 * We use the architected A64 NOP in arch_static_branch, so there's no
+	 * need to patch an identical A64 NOP over the top of it here. The core
+	 * will call arch_jump_label_transform from a module notifier if the
+	 * NOP needs to be replaced by a branch.
+	 */
+}
+
+#endif	/* HAVE_JUMP_LABEL */

arch/arm64/kernel/kgdb.c

@@ -0,0 +1,336 @@
+/*
+ * AArch64 KGDB support
+ *
+ * Based on arch/arm/kernel/kgdb.c
+ *
+ * Copyright (C) 2013 Cavium Inc.
+ * Author: Vijaya Kumar K <vijaya.kumar@caviumnetworks.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/irq.h>
+#include <linux/kdebug.h>
+#include <linux/kgdb.h>
+#include <asm/traps.h>
+
+struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
+	{ "x0", 8, offsetof(struct pt_regs, regs[0])},
+	{ "x1", 8, offsetof(struct pt_regs, regs[1])},
+	{ "x2", 8, offsetof(struct pt_regs, regs[2])},
+	{ "x3", 8, offsetof(struct pt_regs, regs[3])},
+	{ "x4", 8, offsetof(struct pt_regs, regs[4])},
+	{ "x5", 8, offsetof(struct pt_regs, regs[5])},
+	{ "x6", 8, offsetof(struct pt_regs, regs[6])},
+	{ "x7", 8, offsetof(struct pt_regs, regs[7])},
+	{ "x8", 8, offsetof(struct pt_regs, regs[8])},
+	{ "x9", 8, offsetof(struct pt_regs, regs[9])},
+	{ "x10", 8, offsetof(struct pt_regs, regs[10])},
+	{ "x11", 8, offsetof(struct pt_regs, regs[11])},
+	{ "x12", 8, offsetof(struct pt_regs, regs[12])},
+	{ "x13", 8, offsetof(struct pt_regs, regs[13])},
+	{ "x14", 8, offsetof(struct pt_regs, regs[14])},
+	{ "x15", 8, offsetof(struct pt_regs, regs[15])},
+	{ "x16", 8, offsetof(struct pt_regs, regs[16])},
+	{ "x17", 8, offsetof(struct pt_regs, regs[17])},
+	{ "x18", 8, offsetof(struct pt_regs, regs[18])},
+	{ "x19", 8, offsetof(struct pt_regs, regs[19])},
+	{ "x20", 8, offsetof(struct pt_regs, regs[20])},
+	{ "x21", 8, offsetof(struct pt_regs, regs[21])},
+	{ "x22", 8, offsetof(struct pt_regs, regs[22])},
+	{ "x23", 8, offsetof(struct pt_regs, regs[23])},
+	{ "x24", 8, offsetof(struct pt_regs, regs[24])},
+	{ "x25", 8, offsetof(struct pt_regs, regs[25])},
+	{ "x26", 8, offsetof(struct pt_regs, regs[26])},
+	{ "x27", 8, offsetof(struct pt_regs, regs[27])},
+	{ "x28", 8, offsetof(struct pt_regs, regs[28])},
+	{ "x29", 8, offsetof(struct pt_regs, regs[29])},
+	{ "x30", 8, offsetof(struct pt_regs, regs[30])},
+	{ "sp", 8, offsetof(struct pt_regs, sp)},
+	{ "pc", 8, offsetof(struct pt_regs, pc)},
+	{ "pstate", 8, offsetof(struct pt_regs, pstate)},
+	{ "v0", 16, -1 },
+	{ "v1", 16, -1 },
+	{ "v2", 16, -1 },
+	{ "v3", 16, -1 },
+	{ "v4", 16, -1 },
+	{ "v5", 16, -1 },
+	{ "v6", 16, -1 },
+	{ "v7", 16, -1 },
+	{ "v8", 16, -1 },
+	{ "v9", 16, -1 },
+	{ "v10", 16, -1 },
+	{ "v11", 16, -1 },
+	{ "v12", 16, -1 },
+	{ "v13", 16, -1 },
+	{ "v14", 16, -1 },
+	{ "v15", 16, -1 },
+	{ "v16", 16, -1 },
+	{ "v17", 16, -1 },
+	{ "v18", 16, -1 },
+	{ "v19", 16, -1 },
+	{ "v20", 16, -1 },
+	{ "v21", 16, -1 },
+	{ "v22", 16, -1 },
+	{ "v23", 16, -1 },
+	{ "v24", 16, -1 },
+	{ "v25", 16, -1 },
+	{ "v26", 16, -1 },
+	{ "v27", 16, -1 },
+	{ "v28", 16, -1 },
+	{ "v29", 16, -1 },
+	{ "v30", 16, -1 },
+	{ "v31", 16, -1 },
+	{ "fpsr", 4, -1 },
+	{ "fpcr", 4, -1 },
+};
+
+char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
+{
+	if (regno >= DBG_MAX_REG_NUM || regno < 0)
+		return NULL;
+
+	if (dbg_reg_def[regno].offset != -1)
+		memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
+		       dbg_reg_def[regno].size);
+	else
+		memset(mem, 0, dbg_reg_def[regno].size);
+	return dbg_reg_def[regno].name;
+}
+
+int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
+{
+	if (regno >= DBG_MAX_REG_NUM || regno < 0)
+		return -EINVAL;
+
+	if (dbg_reg_def[regno].offset != -1)
+		memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
+		       dbg_reg_def[regno].size);
+	return 0;
+}
+
+void
+sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
+{
+	struct pt_regs *thread_regs;
+
+	/* Initialize to zero */
+	memset((char *)gdb_regs, 0, NUMREGBYTES);
+	thread_regs = task_pt_regs(task);
+	memcpy((void *)gdb_regs, (void *)thread_regs->regs, GP_REG_BYTES);
+}
+
+void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
+{
+	regs->pc = pc;
+}
+
+static int compiled_break;
+
+static void kgdb_arch_update_addr(struct pt_regs *regs,
+				char *remcom_in_buffer)
+{
+	unsigned long addr;
+	char *ptr;
+
+	ptr = &remcom_in_buffer[1];
+	if (kgdb_hex2long(&ptr, &addr))
+		kgdb_arch_set_pc(regs, addr);
+	else if (compiled_break == 1)
+		kgdb_arch_set_pc(regs, regs->pc + 4);
+
+	compiled_break = 0;
+}
+
+int kgdb_arch_handle_exception(int exception_vector, int signo,
+			       int err_code, char *remcom_in_buffer,
+			       char *remcom_out_buffer,
+			       struct pt_regs *linux_regs)
+{
+	int err;
+
+	switch (remcom_in_buffer[0]) {
+	case 'D':
+	case 'k':
+		/*
+		 * Packet D (Detach), k (kill). No special handling
+		 * is required here. Handle same as c packet.
+		 */
+	case 'c':
+		/*
+		 * Packet c (Continue) to continue executing.
+		 * Set pc to required address.
+		 * Try to read optional parameter and set pc.
+		 * If this was a compiled breakpoint, we need to move
+		 * to the next instruction else we will just breakpoint
+		 * over and over again.
+		 */
+		kgdb_arch_update_addr(linux_regs, remcom_in_buffer);
+		atomic_set(&kgdb_cpu_doing_single_step, -1);
+		kgdb_single_step =  0;
+
+		/*
+		 * Received continue command, disable single step
+		 */
+		if (kernel_active_single_step())
+			kernel_disable_single_step();
+
+		err = 0;
+		break;
+	case 's':
+		/*
+		 * Update step address value with address passed
+		 * with step packet.
+		 * On debug exception return PC is copied to ELR
+		 * So just update PC.
+		 * If no step address is passed, resume from the address
+		 * pointed by PC. Do not update PC
+		 */
+		kgdb_arch_update_addr(linux_regs, remcom_in_buffer);
+		atomic_set(&kgdb_cpu_doing_single_step, raw_smp_processor_id());
+		kgdb_single_step =  1;
+
+		/*
+		 * Enable single step handling
+		 */
+		if (!kernel_active_single_step())
+			kernel_enable_single_step(linux_regs);
+		err = 0;
+		break;
+	default:
+		err = -1;
+	}
+	return err;
+}
+
+static int kgdb_brk_fn(struct pt_regs *regs, unsigned int esr)
+{
+	kgdb_handle_exception(1, SIGTRAP, 0, regs);
+	return 0;
+}
+
+static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int esr)
+{
+	compiled_break = 1;
+	kgdb_handle_exception(1, SIGTRAP, 0, regs);
+
+	return 0;
+}
+
+static int kgdb_step_brk_fn(struct pt_regs *regs, unsigned int esr)
+{
+	kgdb_handle_exception(1, SIGTRAP, 0, regs);
+	return 0;
+}
+
+static struct break_hook kgdb_brkpt_hook = {
+	.esr_mask	= 0xffffffff,
+	.esr_val	= DBG_ESR_VAL_BRK(KGDB_DYN_DBG_BRK_IMM),
+	.fn		= kgdb_brk_fn
+};
+
+static struct break_hook kgdb_compiled_brkpt_hook = {
+	.esr_mask	= 0xffffffff,
+	.esr_val	= DBG_ESR_VAL_BRK(KGDB_COMPILED_DBG_BRK_IMM),
+	.fn		= kgdb_compiled_brk_fn
+};
+
+static struct step_hook kgdb_step_hook = {
+	.fn		= kgdb_step_brk_fn
+};
+
+static void kgdb_call_nmi_hook(void *ignored)
+{
+	kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
+}
+
+void kgdb_roundup_cpus(unsigned long flags)
+{
+	local_irq_enable();
+	smp_call_function(kgdb_call_nmi_hook, NULL, 0);
+	local_irq_disable();
+}
+
+static int __kgdb_notify(struct die_args *args, unsigned long cmd)
+{
+	struct pt_regs *regs = args->regs;
+
+	if (kgdb_handle_exception(1, args->signr, cmd, regs))
+		return NOTIFY_DONE;
+	return NOTIFY_STOP;
+}
+
+static int
+kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
+{
+	unsigned long flags;
+	int ret;
+
+	local_irq_save(flags);
+	ret = __kgdb_notify(ptr, cmd);
+	local_irq_restore(flags);
+
+	return ret;
+}
+
+static struct notifier_block kgdb_notifier = {
+	.notifier_call	= kgdb_notify,
+	/*
+	 * Want to be lowest priority
+	 */
+	.priority	= -INT_MAX,
+};
+
+/*
+ * kgdb_arch_init - Perform any architecture specific initalization.
+ * This function will handle the initalization of any architecture
+ * specific callbacks.
+ */
+int kgdb_arch_init(void)
+{
+	int ret = register_die_notifier(&kgdb_notifier);
+
+	if (ret != 0)
+		return ret;
+
+	register_break_hook(&kgdb_brkpt_hook);
+	register_break_hook(&kgdb_compiled_brkpt_hook);
+	register_step_hook(&kgdb_step_hook);
+	return 0;
+}
+
+/*
+ * kgdb_arch_exit - Perform any architecture specific uninitalization.
+ * This function will handle the uninitalization of any architecture
+ * specific callbacks, for dynamic registration and unregistration.
+ */
+void kgdb_arch_exit(void)
+{
+	unregister_break_hook(&kgdb_brkpt_hook);
+	unregister_break_hook(&kgdb_compiled_brkpt_hook);
+	unregister_step_hook(&kgdb_step_hook);
+	unregister_die_notifier(&kgdb_notifier);
+}
+
+/*
+ * ARM instructions are always in LE.
+ * Break instruction is encoded in LE format
+ */
+struct kgdb_arch arch_kgdb_ops = {
+	.gdb_bpt_instr = {
+		KGDB_DYN_BRK_INS_BYTE0,
+		KGDB_DYN_BRK_INS_BYTE1,
+		KGDB_DYN_BRK_INS_BYTE2,
+		KGDB_DYN_BRK_INS_BYTE3,
+	}
+};

arch/arm64/kernel/kuser32.S

@@ -0,0 +1,118 @@
+/*
+ * Low-level user helpers placed in the vectors page for AArch32.
+ * Based on the kuser helpers in arch/arm/kernel/entry-armv.S.
+ *
+ * Copyright (C) 2005-2011 Nicolas Pitre <nico@fluxnic.net>
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * AArch32 user helpers.
+ *
+ * Each segment is 32-byte aligned and will be moved to the top of the high
+ * vector page.  New segments (if ever needed) must be added in front of
+ * existing ones.  This mechanism should be used only for things that are
+ * really small and justified, and not be abused freely.
+ *
+ * See Documentation/arm/kernel_user_helpers.txt for formal definitions.
+ */
+
+#include <asm/unistd.h>
+
+	.align	5
+	.globl	__kuser_helper_start
+__kuser_helper_start:
+
+__kuser_cmpxchg64:			// 0xffff0f60
+	.inst	0xe92d00f0		//	push		{r4, r5, r6, r7}
+	.inst	0xe1c040d0		//	ldrd		r4, r5, [r0]
+	.inst	0xe1c160d0		//	ldrd		r6, r7, [r1]
+	.inst	0xe1b20f9f		// 1:	ldrexd		r0, r1, [r2]
+	.inst	0xe0303004		//	eors		r3, r0, r4
+	.inst	0x00313005		//	eoreqs		r3, r1, r5
+	.inst	0x01a23e96		//	stlexdeq	r3, r6, [r2]
+	.inst	0x03330001		//	teqeq		r3, #1
+	.inst	0x0afffff9		//	beq		1b
+	.inst	0xf57ff05b		//	dmb		ish
+	.inst	0xe2730000		//	rsbs		r0, r3, #0
+	.inst	0xe8bd00f0		//	pop		{r4, r5, r6, r7}
+	.inst	0xe12fff1e		//	bx		lr
+
+	.align	5
+__kuser_memory_barrier:			// 0xffff0fa0
+	.inst	0xf57ff05b		//	dmb		ish
+	.inst	0xe12fff1e		//	bx		lr
+
+	.align	5
+__kuser_cmpxchg:			// 0xffff0fc0
+	.inst	0xe1923f9f		// 1:	ldrex		r3, [r2]
+	.inst	0xe0533000		//	subs		r3, r3, r0
+	.inst	0x01823e91		//	stlexeq		r3, r1, [r2]
+	.inst	0x03330001		//	teqeq		r3, #1
+	.inst	0x0afffffa		//	beq		1b
+	.inst	0xf57ff05b		//	dmb		ish
+	.inst	0xe2730000		//	rsbs		r0, r3, #0
+	.inst	0xe12fff1e		//	bx		lr
+
+	.align	5
+__kuser_get_tls:			// 0xffff0fe0
+	.inst	0xee1d0f70		//	mrc		p15, 0, r0, c13, c0, 3
+	.inst	0xe12fff1e		//	bx		lr
+	.rep	5
+	.word	0
+	.endr
+
+__kuser_helper_version:			// 0xffff0ffc
+	.word	((__kuser_helper_end - __kuser_helper_start) >> 5)
+	.globl	__kuser_helper_end
+__kuser_helper_end:
+
+/*
+ * AArch32 sigreturn code
+ *
+ * For ARM syscalls, the syscall number has to be loaded into r7.
+ * We do not support an OABI userspace.
+ *
+ * For Thumb syscalls, we also pass the syscall number via r7. We therefore
+ * need two 16-bit instructions.
+ */
+	.globl __aarch32_sigret_code_start
+__aarch32_sigret_code_start:
+
+	/*
+	 * ARM Code
+	 */
+	.byte	__NR_compat_sigreturn, 0x70, 0xa0, 0xe3	// mov	r7, #__NR_compat_sigreturn
+	.byte	__NR_compat_sigreturn, 0x00, 0x00, 0xef	// svc	#__NR_compat_sigreturn
+
+	/*
+	 * Thumb code
+	 */
+	.byte	__NR_compat_sigreturn, 0x27			// svc	#__NR_compat_sigreturn
+	.byte	__NR_compat_sigreturn, 0xdf			// mov	r7, #__NR_compat_sigreturn
+
+	/*
+	 * ARM code
+	 */
+	.byte	__NR_compat_rt_sigreturn, 0x70, 0xa0, 0xe3	// mov	r7, #__NR_compat_rt_sigreturn
+	.byte	__NR_compat_rt_sigreturn, 0x00, 0x00, 0xef	// svc	#__NR_compat_rt_sigreturn
+
+	/*
+	 * Thumb code
+	 */
+	.byte	__NR_compat_rt_sigreturn, 0x27			// svc	#__NR_compat_rt_sigreturn
+	.byte	__NR_compat_rt_sigreturn, 0xdf			// mov	r7, #__NR_compat_rt_sigreturn
+
+        .globl __aarch32_sigret_code_end
+__aarch32_sigret_code_end:

arch/arm64/kernel/machine_kexec.c

@@ -0,0 +1,102 @@
+/*
+ * machine_kexec.c - arm64 specific parts of kexec
+ */
+
+#define DEBUG 1
+
+#include <linux/irq.h>
+#include <linux/kexec.h>
+#include <linux/mm.h>
+#include <linux/of_fdt.h>
+#include <linux/uaccess.h>
+#include <linux/delay.h>
+
+#include <asm/cacheflush.h>
+#include <asm/system_misc.h>
+
+#if 0
+static atomic_t waiting_for_crash_ipi;
+#endif
+
+/*
+ * find_dtb_addr -  Helper routine to find the start of the device tree.
+ */
+
+int machine_kexec_prepare(struct kimage *image)
+{
+	return 0;
+}
+
+void machine_kexec_cleanup(struct kimage *image)
+{
+}
+
+void machine_crash_nonpanic_core(void *unused)
+{
+	struct pt_regs regs;
+
+	crash_setup_regs(&regs, NULL);
+#if 0
+	pr_debug("CPU %u will stop doing anything useful since another CPU has crashed\n",
+	       smp_processor_id());
+#endif
+	crash_save_cpu(&regs, smp_processor_id());
+	flush_cache_all();
+#if 0
+	atomic_dec(&waiting_for_crash_ipi);
+#endif
+}
+
+#if 0
+static void machine_kexec_mask_interrupts(void)
+{
+	unsigned int i;
+	struct irq_desc *desc;
+
+	for_each_irq_desc(i, desc) {
+		struct irq_chip *chip;
+
+		chip = irq_desc_get_chip(desc);
+		if (!chip)
+			continue;
+
+		if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
+			chip->irq_eoi(&desc->irq_data);
+
+		if (chip->irq_mask)
+			chip->irq_mask(&desc->irq_data);
+
+		if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
+			chip->irq_disable(&desc->irq_data);
+	}
+}
+#endif
+
+void machine_crash_shutdown(struct pt_regs *regs)
+{
+#if 0
+	unsigned long msecs;
+
+	local_irq_disable();
+
+	atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
+	smp_call_function(machine_crash_nonpanic_core, NULL, false);
+	msecs = 1000; /* Wait at most a second for the other cpus to stop */
+	while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
+		mdelay(1);
+		msecs--;
+	}
+	if (atomic_read(&waiting_for_crash_ipi) > 0)
+		pr_debug("Non-crashing CPUs did not react to IPI\n");
+#endif
+	crash_save_cpu(regs, smp_processor_id());
+#if 0
+	machine_kexec_mask_interrupts();
+#endif
+}
+/*
+ * Function pointer to optional machine-specific reinitialization
+ */
+void machine_kexec(struct kimage *image)
+{
+}

arch/arm64/kernel/module.c

@@ -0,0 +1,396 @@
+/*
+ * AArch64 loadable module support.
+ *
+ * Copyright (C) 2012 ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/elf.h>
+#include <linux/gfp.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/moduleloader.h>
+#include <linux/vmalloc.h>
+#include <asm/insn.h>
+
+#define	AARCH64_INSN_IMM_MOVNZ		AARCH64_INSN_IMM_MAX
+#define	AARCH64_INSN_IMM_MOVK		AARCH64_INSN_IMM_16
+
+void *module_alloc(unsigned long size)
+{
+	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
+				    GFP_KERNEL, PAGE_KERNEL_EXEC, NUMA_NO_NODE,
+				    __builtin_return_address(0));
+}
+
+enum aarch64_reloc_op {
+	RELOC_OP_NONE,
+	RELOC_OP_ABS,
+	RELOC_OP_PREL,
+	RELOC_OP_PAGE,
+};
+
+static u64 do_reloc(enum aarch64_reloc_op reloc_op, void *place, u64 val)
+{
+	switch (reloc_op) {
+	case RELOC_OP_ABS:
+		return val;
+	case RELOC_OP_PREL:
+		return val - (u64)place;
+	case RELOC_OP_PAGE:
+		return (val & ~0xfff) - ((u64)place & ~0xfff);
+	case RELOC_OP_NONE:
+		return 0;
+	}
+
+	pr_err("do_reloc: unknown relocation operation %d\n", reloc_op);
+	return 0;
+}
+
+static int reloc_data(enum aarch64_reloc_op op, void *place, u64 val, int len)
+{
+	u64 imm_mask = (1 << len) - 1;
+	s64 sval = do_reloc(op, place, val);
+
+	switch (len) {
+	case 16:
+		*(s16 *)place = sval;
+		break;
+	case 32:
+		*(s32 *)place = sval;
+		break;
+	case 64:
+		*(s64 *)place = sval;
+		break;
+	default:
+		pr_err("Invalid length (%d) for data relocation\n", len);
+		return 0;
+	}
+
+	/*
+	 * Extract the upper value bits (including the sign bit) and
+	 * shift them to bit 0.
+	 */
+	sval = (s64)(sval & ~(imm_mask >> 1)) >> (len - 1);
+
+	/*
+	 * Overflow has occurred if the value is not representable in
+	 * len bits (i.e the bottom len bits are not sign-extended and
+	 * the top bits are not all zero).
+	 */
+	if ((u64)(sval + 1) > 2)
+		return -ERANGE;
+
+	return 0;
+}
+
+static int reloc_insn_movw(enum aarch64_reloc_op op, void *place, u64 val,
+			   int lsb, enum aarch64_insn_imm_type imm_type)
+{
+	u64 imm, limit = 0;
+	s64 sval;
+	u32 insn = le32_to_cpu(*(u32 *)place);
+
+	sval = do_reloc(op, place, val);
+	sval >>= lsb;
+	imm = sval & 0xffff;
+
+	if (imm_type == AARCH64_INSN_IMM_MOVNZ) {
+		/*
+		 * For signed MOVW relocations, we have to manipulate the
+		 * instruction encoding depending on whether or not the
+		 * immediate is less than zero.
+		 */
+		insn &= ~(3 << 29);
+		if ((s64)imm >= 0) {
+			/* >=0: Set the instruction to MOVZ (opcode 10b). */
+			insn |= 2 << 29;
+		} else {
+			/*
+			 * <0: Set the instruction to MOVN (opcode 00b).
+			 *     Since we've masked the opcode already, we
+			 *     don't need to do anything other than
+			 *     inverting the new immediate field.
+			 */
+			imm = ~imm;
+		}
+		imm_type = AARCH64_INSN_IMM_MOVK;
+	}
+
+	/* Update the instruction with the new encoding. */
+	insn = aarch64_insn_encode_immediate(imm_type, insn, imm);
+	*(u32 *)place = cpu_to_le32(insn);
+
+	/* Shift out the immediate field. */
+	sval >>= 16;
+
+	/*
+	 * For unsigned immediates, the overflow check is straightforward.
+	 * For signed immediates, the sign bit is actually the bit past the
+	 * most significant bit of the field.
+	 * The AARCH64_INSN_IMM_16 immediate type is unsigned.
+	 */
+	if (imm_type != AARCH64_INSN_IMM_16) {
+		sval++;
+		limit++;
+	}
+
+	/* Check the upper bits depending on the sign of the immediate. */
+	if ((u64)sval > limit)
+		return -ERANGE;
+
+	return 0;
+}
+
+static int reloc_insn_imm(enum aarch64_reloc_op op, void *place, u64 val,
+			  int lsb, int len, enum aarch64_insn_imm_type imm_type)
+{
+	u64 imm, imm_mask;
+	s64 sval;
+	u32 insn = le32_to_cpu(*(u32 *)place);
+
+	/* Calculate the relocation value. */
+	sval = do_reloc(op, place, val);
+	sval >>= lsb;
+
+	/* Extract the value bits and shift them to bit 0. */
+	imm_mask = (BIT(lsb + len) - 1) >> lsb;
+	imm = sval & imm_mask;
+
+	/* Update the instruction's immediate field. */
+	insn = aarch64_insn_encode_immediate(imm_type, insn, imm);
+	*(u32 *)place = cpu_to_le32(insn);
+
+	/*
+	 * Extract the upper value bits (including the sign bit) and
+	 * shift them to bit 0.
+	 */
+	sval = (s64)(sval & ~(imm_mask >> 1)) >> (len - 1);
+
+	/*
+	 * Overflow has occurred if the upper bits are not all equal to
+	 * the sign bit of the value.
+	 */
+	if ((u64)(sval + 1) >= 2)
+		return -ERANGE;
+
+	return 0;
+}
+
+int apply_relocate_add(Elf64_Shdr *sechdrs,
+		       const char *strtab,
+		       unsigned int symindex,
+		       unsigned int relsec,
+		       struct module *me)
+{
+	unsigned int i;
+	int ovf;
+	bool overflow_check;
+	Elf64_Sym *sym;
+	void *loc;
+	u64 val;
+	Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
+
+	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+		/* loc corresponds to P in the AArch64 ELF document. */
+		loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+			+ rel[i].r_offset;
+
+		/* sym is the ELF symbol we're referring to. */
+		sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
+			+ ELF64_R_SYM(rel[i].r_info);
+
+		/* val corresponds to (S + A) in the AArch64 ELF document. */
+		val = sym->st_value + rel[i].r_addend;
+
+		/* Check for overflow by default. */
+		overflow_check = true;
+
+		/* Perform the static relocation. */
+		switch (ELF64_R_TYPE(rel[i].r_info)) {
+		/* Null relocations. */
+		case R_ARM_NONE:
+		case R_AARCH64_NONE:
+			ovf = 0;
+			break;
+
+		/* Data relocations. */
+		case R_AARCH64_ABS64:
+			overflow_check = false;
+			ovf = reloc_data(RELOC_OP_ABS, loc, val, 64);
+			break;
+		case R_AARCH64_ABS32:
+			ovf = reloc_data(RELOC_OP_ABS, loc, val, 32);
+			break;
+		case R_AARCH64_ABS16:
+			ovf = reloc_data(RELOC_OP_ABS, loc, val, 16);
+			break;
+		case R_AARCH64_PREL64:
+			overflow_check = false;
+			ovf = reloc_data(RELOC_OP_PREL, loc, val, 64);
+			break;
+		case R_AARCH64_PREL32:
+			ovf = reloc_data(RELOC_OP_PREL, loc, val, 32);
+			break;
+		case R_AARCH64_PREL16:
+			ovf = reloc_data(RELOC_OP_PREL, loc, val, 16);
+			break;
+
+		/* MOVW instruction relocations. */
+		case R_AARCH64_MOVW_UABS_G0_NC:
+			overflow_check = false;
+		case R_AARCH64_MOVW_UABS_G0:
+			ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 0,
+					      AARCH64_INSN_IMM_16);
+			break;
+		case R_AARCH64_MOVW_UABS_G1_NC:
+			overflow_check = false;
+		case R_AARCH64_MOVW_UABS_G1:
+			ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 16,
+					      AARCH64_INSN_IMM_16);
+			break;
+		case R_AARCH64_MOVW_UABS_G2_NC:
+			overflow_check = false;
+		case R_AARCH64_MOVW_UABS_G2:
+			ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 32,
+					      AARCH64_INSN_IMM_16);
+			break;
+		case R_AARCH64_MOVW_UABS_G3:
+			/* We're using the top bits so we can't overflow. */
+			overflow_check = false;
+			ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 48,
+					      AARCH64_INSN_IMM_16);
+			break;
+		case R_AARCH64_MOVW_SABS_G0:
+			ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 0,
+					      AARCH64_INSN_IMM_MOVNZ);
+			break;
+		case R_AARCH64_MOVW_SABS_G1:
+			ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 16,
+					      AARCH64_INSN_IMM_MOVNZ);
+			break;
+		case R_AARCH64_MOVW_SABS_G2:
+			ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 32,
+					      AARCH64_INSN_IMM_MOVNZ);
+			break;
+		case R_AARCH64_MOVW_PREL_G0_NC:
+			overflow_check = false;
+			ovf = reloc_insn_movw(RELOC_OP_PREL, loc, val, 0,
+					      AARCH64_INSN_IMM_MOVK);
+			break;
+		case R_AARCH64_MOVW_PREL_G0:
+			ovf = reloc_insn_movw(RELOC_OP_PREL, loc, val, 0,
+					      AARCH64_INSN_IMM_MOVNZ);
+			break;
+		case R_AARCH64_MOVW_PREL_G1_NC:
+			overflow_check = false;
+			ovf = reloc_insn_movw(RELOC_OP_PREL, loc, val, 16,
+					      AARCH64_INSN_IMM_MOVK);
+			break;
+		case R_AARCH64_MOVW_PREL_G1:
+			ovf = reloc_insn_movw(RELOC_OP_PREL, loc, val, 16,
+					      AARCH64_INSN_IMM_MOVNZ);
+			break;
+		case R_AARCH64_MOVW_PREL_G2_NC:
+			overflow_check = false;
+			ovf = reloc_insn_movw(RELOC_OP_PREL, loc, val, 32,
+					      AARCH64_INSN_IMM_MOVK);
+			break;
+		case R_AARCH64_MOVW_PREL_G2:
+			ovf = reloc_insn_movw(RELOC_OP_PREL, loc, val, 32,
+					      AARCH64_INSN_IMM_MOVNZ);
+			break;
+		case R_AARCH64_MOVW_PREL_G3:
+			/* We're using the top bits so we can't overflow. */
+			overflow_check = false;
+			ovf = reloc_insn_movw(RELOC_OP_PREL, loc, val, 48,
+					      AARCH64_INSN_IMM_MOVNZ);
+			break;
+
+		/* Immediate instruction relocations. */
+		case R_AARCH64_LD_PREL_LO19:
+			ovf = reloc_insn_imm(RELOC_OP_PREL, loc, val, 2, 19,
+					     AARCH64_INSN_IMM_19);
+			break;
+		case R_AARCH64_ADR_PREL_LO21:
+			ovf = reloc_insn_imm(RELOC_OP_PREL, loc, val, 0, 21,
+					     AARCH64_INSN_IMM_ADR);
+			break;
+		case R_AARCH64_ADR_PREL_PG_HI21_NC:
+			overflow_check = false;
+		case R_AARCH64_ADR_PREL_PG_HI21:
+			ovf = reloc_insn_imm(RELOC_OP_PAGE, loc, val, 12, 21,
+					     AARCH64_INSN_IMM_ADR);
+			break;
+		case R_AARCH64_ADD_ABS_LO12_NC:
+		case R_AARCH64_LDST8_ABS_LO12_NC:
+			overflow_check = false;
+			ovf = reloc_insn_imm(RELOC_OP_ABS, loc, val, 0, 12,
+					     AARCH64_INSN_IMM_12);
+			break;
+		case R_AARCH64_LDST16_ABS_LO12_NC:
+			overflow_check = false;
+			ovf = reloc_insn_imm(RELOC_OP_ABS, loc, val, 1, 11,
+					     AARCH64_INSN_IMM_12);
+			break;
+		case R_AARCH64_LDST32_ABS_LO12_NC:
+			overflow_check = false;
+			ovf = reloc_insn_imm(RELOC_OP_ABS, loc, val, 2, 10,
+					     AARCH64_INSN_IMM_12);
+			break;
+		case R_AARCH64_LDST64_ABS_LO12_NC:
+			overflow_check = false;
+			ovf = reloc_insn_imm(RELOC_OP_ABS, loc, val, 3, 9,
+					     AARCH64_INSN_IMM_12);
+			break;
+		case R_AARCH64_LDST128_ABS_LO12_NC:
+			overflow_check = false;
+			ovf = reloc_insn_imm(RELOC_OP_ABS, loc, val, 4, 8,
+					     AARCH64_INSN_IMM_12);
+			break;
+		case R_AARCH64_TSTBR14:
+			ovf = reloc_insn_imm(RELOC_OP_PREL, loc, val, 2, 14,
+					     AARCH64_INSN_IMM_14);
+			break;
+		case R_AARCH64_CONDBR19:
+			ovf = reloc_insn_imm(RELOC_OP_PREL, loc, val, 2, 19,
+					     AARCH64_INSN_IMM_19);
+			break;
+		case R_AARCH64_JUMP26:
+		case R_AARCH64_CALL26:
+			ovf = reloc_insn_imm(RELOC_OP_PREL, loc, val, 2, 26,
+					     AARCH64_INSN_IMM_26);
+			break;
+
+		default:
+			pr_err("module %s: unsupported RELA relocation: %llu\n",
+			       me->name, ELF64_R_TYPE(rel[i].r_info));
+			return -ENOEXEC;
+		}
+
+		if (overflow_check && ovf == -ERANGE)
+			goto overflow;
+
+	}
+
+	return 0;
+
+overflow:
+	pr_err("module %s: overflow in relocation type %d val %Lx\n",
+	       me->name, (int)ELF64_R_TYPE(rel[i].r_info), val);
+	return -ENOEXEC;
+}

arch/arm64/kernel/pci.c

@@ -0,0 +1,48 @@
+/*
+ * Code borrowed from powerpc/kernel/pci-common.c
+ *
+ * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
+ * Copyright (C) 2014 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+
+#include <asm/pci-bridge.h>
+
+/*
+ * Called after each bus is probed, but before its children are examined
+ */
+void pcibios_fixup_bus(struct pci_bus *bus)
+{
+	/* nothing to do, expected to be removed in the future */
+}
+
+/*
+ * We don't have to worry about legacy ISA devices, so nothing to do here
+ */
+resource_size_t pcibios_align_resource(void *data, const struct resource *res,
+				resource_size_t size, resource_size_t align)
+{
+	return res->start;
+}
+
+/*
+ * Try to assign the IRQ number from DT when adding a new device
+ */
+int pcibios_add_device(struct pci_dev *dev)
+{
+	dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
+
+	return 0;
+}

arch/arm64/kernel/perf_regs.c

@@ -0,0 +1,52 @@
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/perf_event.h>
+#include <linux/bug.h>
+
+#include <asm/compat.h>
+#include <asm/perf_regs.h>
+#include <asm/ptrace.h>
+
+u64 perf_reg_value(struct pt_regs *regs, int idx)
+{
+	if (WARN_ON_ONCE((u32)idx >= PERF_REG_ARM64_MAX))
+		return 0;
+
+	/*
+	 * Compat (i.e. 32 bit) mode:
+	 * - PC has been set in the pt_regs struct in kernel_entry,
+	 * - Handle SP and LR here.
+	 */
+	if (compat_user_mode(regs)) {
+		if ((u32)idx == PERF_REG_ARM64_SP)
+			return regs->compat_sp;
+		if ((u32)idx == PERF_REG_ARM64_LR)
+			return regs->compat_lr;
+	}
+
+	if ((u32)idx == PERF_REG_ARM64_SP)
+		return regs->sp;
+
+	if ((u32)idx == PERF_REG_ARM64_PC)
+		return regs->pc;
+
+	return regs->regs[idx];
+}
+
+#define REG_RESERVED (~((1ULL << PERF_REG_ARM64_MAX) - 1))
+
+int perf_reg_validate(u64 mask)
+{
+	if (!mask || mask & REG_RESERVED)
+		return -EINVAL;
+
+	return 0;
+}
+
+u64 perf_reg_abi(struct task_struct *task)
+{
+	if (is_compat_thread(task_thread_info(task)))
+		return PERF_SAMPLE_REGS_ABI_32;
+	else
+		return PERF_SAMPLE_REGS_ABI_64;
+}

arch/arm64/kernel/process.c

@@ -0,0 +1,456 @@
+/*
+ * Based on arch/arm/kernel/process.c
+ *
+ * Original Copyright (C) 1995  Linus Torvalds
+ * Copyright (C) 1996-2000 Russell King - Converted to ARM.
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdarg.h>
+
+#include <linux/compat.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/user.h>
+#include <linux/delay.h>
+#include <linux/reboot.h>
+#include <linux/interrupt.h>
+#include <linux/kallsyms.h>
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/elfcore.h>
+#include <linux/pm.h>
+#include <linux/tick.h>
+#include <linux/utsname.h>
+#include <linux/uaccess.h>
+#include <linux/random.h>
+#include <linux/hw_breakpoint.h>
+#include <linux/personality.h>
+#include <linux/notifier.h>
+#include <linux/exynos-ss.h>
+
+#include <asm/compat.h>
+#include <asm/cacheflush.h>
+#include <asm/fpsimd.h>
+#include <asm/mmu_context.h>
+#include <asm/processor.h>
+#include <asm/stacktrace.h>
+
+#ifdef CONFIG_CC_STACKPROTECTOR
+#include <linux/stackprotector.h>
+unsigned long __stack_chk_guard __read_mostly;
+EXPORT_SYMBOL(__stack_chk_guard);
+#endif
+
+void soft_restart(unsigned long addr)
+{
+	setup_mm_for_reboot();
+	cpu_soft_restart(virt_to_phys(cpu_reset), addr);
+	/* Should never get here */
+	BUG();
+}
+
+/*
+ * Function pointers to optional machine specific functions
+ */
+void (*pm_power_off)(void);
+EXPORT_SYMBOL_GPL(pm_power_off);
+
+void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
+
+/*
+ * This is our default idle handler.
+ */
+void arch_cpu_idle(void)
+{
+	/*
+	 * This should do all the clock switching and wait for interrupt
+	 * tricks
+	 */
+	cpu_do_idle();
+	local_irq_enable();
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+void arch_cpu_idle_dead(void)
+{
+       cpu_die();
+}
+#endif
+
+/*
+ * Called by kexec, immediately prior to machine_kexec().
+ *
+ * This must completely disable all secondary CPUs; simply causing those CPUs
+ * to execute e.g. a RAM-based pin loop is not sufficient. This allows the
+ * kexec'd kernel to use any and all RAM as it sees fit, without having to
+ * avoid any code or data used by any SW CPU pin loop. The CPU hotplug
+ * functionality embodied in disable_nonboot_cpus() to achieve this.
+ */
+void machine_shutdown(void)
+{
+	disable_nonboot_cpus();
+}
+
+/*
+ * Halting simply requires that the secondary CPUs stop performing any
+ * activity (executing tasks, handling interrupts). smp_send_stop()
+ * achieves this.
+ */
+void machine_halt(void)
+{
+	local_irq_disable();
+	smp_send_stop();
+	while (1);
+}
+
+/*
+ * Power-off simply requires that the secondary CPUs stop performing any
+ * activity (executing tasks, handling interrupts). smp_send_stop()
+ * achieves this. When the system power is turned off, it will take all CPUs
+ * with it.
+ */
+void machine_power_off(void)
+{
+	local_irq_disable();
+	smp_send_stop();
+	if (pm_power_off)
+		pm_power_off();
+}
+
+/*
+ * Restart requires that the secondary CPUs stop performing any activity
+ * while the primary CPU resets the system. Systems with a single CPU can
+ * use soft_restart() as their machine descriptor's .restart hook, since that
+ * will cause the only available CPU to reset. Systems with multiple CPUs must
+ * provide a HW restart implementation, to ensure that all CPUs reset at once.
+ * This is required so that any code running after reset on the primary CPU
+ * doesn't have to co-ordinate with other CPUs to ensure they aren't still
+ * executing pre-reset code, and using RAM that the primary CPU's code wishes
+ * to use. Implementing such co-ordination would be essentially impossible.
+ */
+void machine_restart(char *cmd)
+{
+	/* Disable interrupts first */
+	local_irq_disable();
+	smp_send_stop();
+
+	/* Now call the architecture specific reboot code. */
+	if (arm_pm_restart)
+		arm_pm_restart(reboot_mode, cmd);
+	else
+		do_kernel_restart(cmd);
+
+	/*
+	 * Whoops - the architecture was unable to reboot.
+	 */
+	printk("Reboot failed -- System halted\n");
+	while (1);
+}
+
+/*
+ * dump a block of kernel memory from around the given address
+ */
+static void show_data(unsigned long addr, int nbytes, const char *name)
+{
+	int	i, j;
+	int	nlines;
+	u32	*p;
+
+	/*
+	 * don't attempt to dump non-kernel addresses or
+	 * values that are probably just small negative numbers
+	 */
+	if (addr < PAGE_OFFSET || addr > -256UL)
+		return;
+
+	printk("\n%s: %#lx:\n", name, addr);
+
+	/*
+	 * round address down to a 32 bit boundary
+	 * and always dump a multiple of 32 bytes
+	 */
+	p = (u32 *)(addr & ~(sizeof(u32) - 1));
+	nbytes += (addr & (sizeof(u32) - 1));
+	nlines = (nbytes + 31) / 32;
+
+
+	for (i = 0; i < nlines; i++) {
+		/*
+		 * just display low 16 bits of address to keep
+		 * each line of the dump < 80 characters
+		 */
+		printk("%04lx ", (unsigned long)p & 0xffff);
+		for (j = 0; j < 8; j++) {
+			u32	data;
+			if (probe_kernel_address(p, data)) {
+				printk(" ********");
+			} else {
+				printk(" %08x", data);
+			}
+			++p;
+		}
+		printk("\n");
+	}
+}
+
+static void show_extra_register_data(struct pt_regs *regs, int nbytes)
+{
+	mm_segment_t fs;
+	unsigned int i;
+
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+	show_data(regs->pc - nbytes, nbytes * 2, "PC");
+	show_data(regs->regs[30] - nbytes, nbytes * 2, "LR");
+	show_data(regs->sp - nbytes, nbytes * 2, "SP");
+	for (i = 0; i < 30; i++) {
+		char name[4];
+		snprintf(name, sizeof(name), "X%u", i);
+		show_data(regs->regs[i] - nbytes, nbytes * 2, name);
+	}
+	set_fs(fs);
+}
+
+void __show_regs(struct pt_regs *regs)
+{
+	int i, top_reg;
+	u64 lr, sp;
+
+	if (compat_user_mode(regs)) {
+		lr = regs->compat_lr;
+		sp = regs->compat_sp;
+		top_reg = 12;
+	} else {
+		lr = regs->regs[30];
+		sp = regs->sp;
+		top_reg = 29;
+	}
+	if (!user_mode(regs)) {
+		exynos_ss_save_context(regs);
+		/*
+		 *  If you want to see more kernel events after panic,
+		 *  you should modify exynos_ss_set_enable's function 2nd parameter
+		 *  to true.
+		 */
+		exynos_ss_set_enable("log_kevents", false);
+	}
+
+	show_regs_print_info(KERN_DEFAULT);
+	print_symbol("PC is at %s\n", instruction_pointer(regs));
+	print_symbol("LR is at %s\n", lr);
+	printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n",
+	       regs->pc, lr, regs->pstate);
+	printk("sp : %016llx\n", sp);
+	for (i = top_reg; i >= 0; i--) {
+		printk("x%-2d: %016llx ", i, regs->regs[i]);
+		if (i % 2 == 0)
+			printk("\n");
+	}
+	if (!user_mode(regs))
+		show_extra_register_data(regs, 128);
+	printk("\n");
+}
+
+void show_regs(struct pt_regs * regs)
+{
+	printk("\n");
+	__show_regs(regs);
+}
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(void)
+{
+}
+
+static void tls_thread_flush(void)
+{
+	asm ("msr tpidr_el0, xzr");
+
+	if (is_compat_task()) {
+		current->thread.tp_value = 0;
+
+		/*
+		 * We need to ensure ordering between the shadow state and the
+		 * hardware state, so that we don't corrupt the hardware state
+		 * with a stale shadow state during context switch.
+		 */
+		barrier();
+		asm ("msr tpidrro_el0, xzr");
+	}
+}
+
+void flush_thread(void)
+{
+	fpsimd_flush_thread();
+	tls_thread_flush();
+	flush_ptrace_hw_breakpoint(current);
+}
+
+void release_thread(struct task_struct *dead_task)
+{
+}
+
+int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
+{
+	fpsimd_preserve_current_state();
+	*dst = *src;
+	return 0;
+}
+
+asmlinkage void ret_from_fork(void) asm("ret_from_fork");
+
+int copy_thread(unsigned long clone_flags, unsigned long stack_start,
+		unsigned long stk_sz, struct task_struct *p)
+{
+	struct pt_regs *childregs = task_pt_regs(p);
+	unsigned long tls = p->thread.tp_value;
+
+	memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
+
+	if (likely(!(p->flags & PF_KTHREAD))) {
+		*childregs = *current_pt_regs();
+		childregs->regs[0] = 0;
+		if (is_compat_thread(task_thread_info(p))) {
+			if (stack_start)
+				childregs->compat_sp = stack_start;
+		} else {
+			/*
+			 * Read the current TLS pointer from tpidr_el0 as it may be
+			 * out-of-sync with the saved value.
+			 */
+			asm("mrs %0, tpidr_el0" : "=r" (tls));
+			if (stack_start) {
+				/* 16-byte aligned stack mandatory on AArch64 */
+				if (stack_start & 15)
+					return -EINVAL;
+				childregs->sp = stack_start;
+			}
+		}
+		/*
+		 * If a TLS pointer was passed to clone (4th argument), use it
+		 * for the new thread.
+		 */
+		if (clone_flags & CLONE_SETTLS)
+			tls = childregs->regs[3];
+	} else {
+		memset(childregs, 0, sizeof(struct pt_regs));
+		childregs->pstate = PSR_MODE_EL1h;
+		p->thread.cpu_context.x19 = stack_start;
+		p->thread.cpu_context.x20 = stk_sz;
+	}
+	p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
+	p->thread.cpu_context.sp = (unsigned long)childregs;
+	p->thread.tp_value = tls;
+
+	ptrace_hw_copy_thread(p);
+
+	return 0;
+}
+
+static void tls_thread_switch(struct task_struct *next)
+{
+	unsigned long tpidr, tpidrro;
+
+	if (!is_compat_task()) {
+		asm("mrs %0, tpidr_el0" : "=r" (tpidr));
+		current->thread.tp_value = tpidr;
+	}
+
+	if (is_compat_thread(task_thread_info(next))) {
+		tpidr = 0;
+		tpidrro = next->thread.tp_value;
+	} else {
+		tpidr = next->thread.tp_value;
+		tpidrro = 0;
+	}
+
+	asm(
+	"	msr	tpidr_el0, %0\n"
+	"	msr	tpidrro_el0, %1"
+	: : "r" (tpidr), "r" (tpidrro));
+}
+
+/*
+ * Thread switching.
+ */
+struct task_struct *__switch_to(struct task_struct *prev,
+				struct task_struct *next)
+{
+	struct task_struct *last;
+
+	fpsimd_thread_switch(next);
+	tls_thread_switch(next);
+	hw_breakpoint_thread_switch(next);
+	contextidr_thread_switch(next);
+
+	/*
+	 * Complete any pending TLB or cache maintenance on this CPU in case
+	 * the thread migrates to a different CPU.
+	 */
+	dsb(ish);
+
+	/* the actual thread switch */
+	last = cpu_switch_to(prev, next);
+
+	return last;
+}
+
+unsigned long get_wchan(struct task_struct *p)
+{
+	struct stackframe frame;
+	unsigned long stack_page;
+	int count = 0;
+	if (!p || p == current || p->state == TASK_RUNNING)
+		return 0;
+
+	frame.fp = thread_saved_fp(p);
+	frame.sp = thread_saved_sp(p);
+	frame.pc = thread_saved_pc(p);
+	stack_page = (unsigned long)task_stack_page(p);
+	do {
+		if (frame.sp < stack_page ||
+		    frame.sp >= stack_page + THREAD_SIZE ||
+		    unwind_frame(&frame))
+			return 0;
+		if (!in_sched_functions(frame.pc))
+			return frame.pc;
+	} while (count ++ < 16);
+	return 0;
+}
+
+unsigned long arch_align_stack(unsigned long sp)
+{
+	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+		sp -= get_random_int() & ~PAGE_MASK;
+	return sp & ~0xf;
+}
+
+static unsigned long randomize_base(unsigned long base)
+{
+	unsigned long range_end = base + (STACK_RND_MASK << PAGE_SHIFT) + 1;
+	return randomize_range(base, range_end, 0) ? : base;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+	return randomize_base(mm->brk);
+}

arch/arm64/kernel/psci.c

@@ -0,0 +1,603 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Copyright (C) 2013 ARM Limited
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#define pr_fmt(fmt) "psci: " fmt
+
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/smp.h>
+#include <linux/reboot.h>
+#include <linux/pm.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <uapi/linux/psci.h>
+
+#include <asm/compiler.h>
+#include <asm/cpu_ops.h>
+#include <asm/errno.h>
+#include <asm/psci.h>
+#include <asm/smp_plat.h>
+#include <asm/suspend.h>
+#include <asm/system_misc.h>
+
+#define PSCI_POWER_STATE_TYPE_STANDBY		0
+#define PSCI_POWER_STATE_TYPE_POWER_DOWN	1
+
+struct psci_power_state {
+	u16	id;
+	u8	type;
+	u8	affinity_level;
+};
+
+struct psci_operations {
+	int (*cpu_suspend)(struct psci_power_state state,
+			   unsigned long entry_point);
+	int (*cpu_off)(struct psci_power_state state);
+	int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);
+	int (*migrate)(unsigned long cpuid);
+	int (*affinity_info)(unsigned long target_affinity,
+			unsigned long lowest_affinity_level);
+	int (*migrate_info_type)(void);
+};
+
+static struct psci_operations psci_ops;
+
+static int (*invoke_psci_fn)(u64, u64, u64, u64);
+typedef int (*psci_initcall_t)(const struct device_node *);
+
+enum psci_function {
+	PSCI_FN_CPU_SUSPEND,
+	PSCI_FN_CPU_ON,
+	PSCI_FN_CPU_OFF,
+	PSCI_FN_MIGRATE,
+	PSCI_FN_AFFINITY_INFO,
+	PSCI_FN_MIGRATE_INFO_TYPE,
+	PSCI_FN_MAX,
+};
+
+static DEFINE_PER_CPU_READ_MOSTLY(struct psci_power_state *, psci_power_state);
+
+static u32 psci_function_id[PSCI_FN_MAX];
+
+static int psci_to_linux_errno(int errno)
+{
+	switch (errno) {
+	case PSCI_RET_SUCCESS:
+		return 0;
+	case PSCI_RET_NOT_SUPPORTED:
+		return -EOPNOTSUPP;
+	case PSCI_RET_INVALID_PARAMS:
+		return -EINVAL;
+	case PSCI_RET_DENIED:
+		return -EPERM;
+	};
+
+	return -EINVAL;
+}
+
+static u32 psci_power_state_pack(struct psci_power_state state)
+{
+	return ((state.id << PSCI_0_2_POWER_STATE_ID_SHIFT)
+			& PSCI_0_2_POWER_STATE_ID_MASK) |
+		((state.type << PSCI_0_2_POWER_STATE_TYPE_SHIFT)
+		 & PSCI_0_2_POWER_STATE_TYPE_MASK) |
+		((state.affinity_level << PSCI_0_2_POWER_STATE_AFFL_SHIFT)
+		 & PSCI_0_2_POWER_STATE_AFFL_MASK);
+}
+
+static void psci_power_state_unpack(u32 power_state,
+				    struct psci_power_state *state)
+{
+	state->id = (power_state & PSCI_0_2_POWER_STATE_ID_MASK) >>
+			PSCI_0_2_POWER_STATE_ID_SHIFT;
+	state->type = (power_state & PSCI_0_2_POWER_STATE_TYPE_MASK) >>
+			PSCI_0_2_POWER_STATE_TYPE_SHIFT;
+	state->affinity_level =
+			(power_state & PSCI_0_2_POWER_STATE_AFFL_MASK) >>
+			PSCI_0_2_POWER_STATE_AFFL_SHIFT;
+}
+
+/*
+ * The following two functions are invoked via the invoke_psci_fn pointer
+ * and will not be inlined, allowing us to piggyback on the AAPCS.
+ */
+static noinline int __invoke_psci_fn_hvc(u64 function_id, u64 arg0, u64 arg1,
+					 u64 arg2)
+{
+	asm volatile(
+			__asmeq("%0", "x0")
+			__asmeq("%1", "x1")
+			__asmeq("%2", "x2")
+			__asmeq("%3", "x3")
+			"hvc	#0\n"
+		: "+r" (function_id)
+		: "r" (arg0), "r" (arg1), "r" (arg2));
+
+	return function_id;
+}
+
+static noinline int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1,
+					 u64 arg2)
+{
+	asm volatile(
+			__asmeq("%0", "x0")
+			__asmeq("%1", "x1")
+			__asmeq("%2", "x2")
+			__asmeq("%3", "x3")
+			"smc	#0\n"
+		: "+r" (function_id)
+		: "r" (arg0), "r" (arg1), "r" (arg2));
+
+	return function_id;
+}
+
+static int psci_get_version(void)
+{
+	int err;
+
+	err = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
+	return err;
+}
+
+static int psci_cpu_suspend(struct psci_power_state state,
+			    unsigned long entry_point)
+{
+	int err;
+	u32 fn, power_state;
+
+	fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
+	power_state = psci_power_state_pack(state);
+	err = invoke_psci_fn(fn, power_state, entry_point, 0);
+	return psci_to_linux_errno(err);
+}
+
+static int psci_cpu_off(struct psci_power_state state)
+{
+	int err;
+	u32 fn, power_state;
+
+	fn = psci_function_id[PSCI_FN_CPU_OFF];
+	power_state = psci_power_state_pack(state);
+	err = invoke_psci_fn(fn, power_state, 0, 0);
+	return psci_to_linux_errno(err);
+}
+
+static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
+{
+	int err;
+	u32 fn;
+
+	fn = psci_function_id[PSCI_FN_CPU_ON];
+	err = invoke_psci_fn(fn, cpuid, entry_point, 0);
+	return psci_to_linux_errno(err);
+}
+
+static int psci_migrate(unsigned long cpuid)
+{
+	int err;
+	u32 fn;
+
+	fn = psci_function_id[PSCI_FN_MIGRATE];
+	err = invoke_psci_fn(fn, cpuid, 0, 0);
+	return psci_to_linux_errno(err);
+}
+
+static int psci_affinity_info(unsigned long target_affinity,
+		unsigned long lowest_affinity_level)
+{
+	int err;
+	u32 fn;
+
+	fn = psci_function_id[PSCI_FN_AFFINITY_INFO];
+	err = invoke_psci_fn(fn, target_affinity, lowest_affinity_level, 0);
+	return err;
+}
+
+static int psci_migrate_info_type(void)
+{
+	int err;
+	u32 fn;
+
+	fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE];
+	err = invoke_psci_fn(fn, 0, 0, 0);
+	return err;
+}
+
+static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
+						 unsigned int cpu)
+{
+	int i, ret, count = 0;
+	struct psci_power_state *psci_states;
+	struct device_node *state_node;
+
+	/*
+	 * If the PSCI cpu_suspend function hook has not been initialized
+	 * idle states must not be enabled, so bail out
+	 */
+	if (!psci_ops.cpu_suspend)
+		return -EOPNOTSUPP;
+
+	/* Count idle states */
+	while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
+					      count))) {
+		count++;
+		of_node_put(state_node);
+	}
+
+	if (!count)
+		return -ENODEV;
+
+	psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
+	if (!psci_states)
+		return -ENOMEM;
+
+	for (i = 0; i < count; i++) {
+		u32 psci_power_state;
+
+		state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
+
+		ret = of_property_read_u32(state_node,
+					   "arm,psci-suspend-param",
+					   &psci_power_state);
+		if (ret) {
+			pr_warn(" * %s missing arm,psci-suspend-param property\n",
+				state_node->full_name);
+			of_node_put(state_node);
+			goto free_mem;
+		}
+
+		of_node_put(state_node);
+		pr_debug("psci-power-state %#x index %d\n", psci_power_state,
+							    i);
+		psci_power_state_unpack(psci_power_state, &psci_states[i]);
+	}
+	/* Idle states parsed correctly, initialize per-cpu pointer */
+	per_cpu(psci_power_state, cpu) = psci_states;
+	return 0;
+
+free_mem:
+	kfree(psci_states);
+	return ret;
+}
+
+static int get_set_conduit_method(struct device_node *np)
+{
+	const char *method;
+
+	pr_info("probing for conduit method from DT.\n");
+
+	if (of_property_read_string(np, "method", &method)) {
+		pr_warn("missing \"method\" property\n");
+		return -ENXIO;
+	}
+
+	if (!strcmp("hvc", method)) {
+		invoke_psci_fn = __invoke_psci_fn_hvc;
+	} else if (!strcmp("smc", method)) {
+		invoke_psci_fn = __invoke_psci_fn_smc;
+	} else {
+		pr_warn("invalid \"method\" property: %s\n", method);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
+{
+	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
+}
+
+static void psci_sys_poweroff(void)
+{
+	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
+}
+
+/*
+ * PSCI Function IDs for v0.2+ are well defined so use
+ * standard values.
+ */
+static int __init psci_0_2_init(struct device_node *np)
+{
+	int err, ver;
+
+	err = get_set_conduit_method(np);
+
+	if (err)
+		goto out_put_node;
+
+	ver = psci_get_version();
+
+	if (ver == PSCI_RET_NOT_SUPPORTED) {
+		/* PSCI v0.2 mandates implementation of PSCI_ID_VERSION. */
+		pr_err("PSCI firmware does not comply with the v0.2 spec.\n");
+		err = -EOPNOTSUPP;
+		goto out_put_node;
+	} else {
+		pr_info("PSCIv%d.%d detected in firmware.\n",
+				PSCI_VERSION_MAJOR(ver),
+				PSCI_VERSION_MINOR(ver));
+
+		if (PSCI_VERSION_MAJOR(ver) == 0 &&
+				PSCI_VERSION_MINOR(ver) < 2) {
+			err = -EINVAL;
+			pr_err("Conflicting PSCI version detected.\n");
+			goto out_put_node;
+		}
+	}
+
+	pr_info("Using standard PSCI v0.2 function IDs\n");
+	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_CPU_SUSPEND;
+	psci_ops.cpu_suspend = psci_cpu_suspend;
+
+	psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
+	psci_ops.cpu_off = psci_cpu_off;
+
+	psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN64_CPU_ON;
+	psci_ops.cpu_on = psci_cpu_on;
+
+	psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE;
+	psci_ops.migrate = psci_migrate;
+
+	psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN64_AFFINITY_INFO;
+	psci_ops.affinity_info = psci_affinity_info;
+
+	psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] =
+		PSCI_0_2_FN_MIGRATE_INFO_TYPE;
+	psci_ops.migrate_info_type = psci_migrate_info_type;
+
+	arm_pm_restart = psci_sys_reset;
+
+	pm_power_off = psci_sys_poweroff;
+
+out_put_node:
+	of_node_put(np);
+	return err;
+}
+
+/*
+ * PSCI < v0.2 get PSCI Function IDs via DT.
+ */
+static int __init psci_0_1_init(struct device_node *np)
+{
+	u32 id;
+	int err;
+
+	err = get_set_conduit_method(np);
+
+	if (err)
+		goto out_put_node;
+
+	pr_info("Using PSCI v0.1 Function IDs from DT\n");
+
+	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
+		psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
+		psci_ops.cpu_suspend = psci_cpu_suspend;
+	}
+
+	if (!of_property_read_u32(np, "cpu_off", &id)) {
+		psci_function_id[PSCI_FN_CPU_OFF] = id;
+		psci_ops.cpu_off = psci_cpu_off;
+	}
+
+	if (!of_property_read_u32(np, "cpu_on", &id)) {
+		psci_function_id[PSCI_FN_CPU_ON] = id;
+		psci_ops.cpu_on = psci_cpu_on;
+	}
+
+	if (!of_property_read_u32(np, "migrate", &id)) {
+		psci_function_id[PSCI_FN_MIGRATE] = id;
+		psci_ops.migrate = psci_migrate;
+	}
+
+out_put_node:
+	of_node_put(np);
+	return err;
+}
+
+static const struct of_device_id psci_of_match[] __initconst = {
+	{ .compatible = "arm,psci",	.data = psci_0_1_init},
+	{ .compatible = "arm,psci-0.2",	.data = psci_0_2_init},
+	{},
+};
+
+int __init psci_init(void)
+{
+	struct device_node *np;
+	const struct of_device_id *matched_np;
+	psci_initcall_t init_fn;
+
+	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
+
+	if (!np)
+		return -ENODEV;
+
+	init_fn = (psci_initcall_t)matched_np->data;
+	return init_fn(np);
+}
+
+#ifdef CONFIG_SMP
+
+static int __init cpu_psci_cpu_init(struct device_node *dn, unsigned int cpu)
+{
+	return 0;
+}
+
+static int __init cpu_psci_cpu_prepare(unsigned int cpu)
+{
+	if (!psci_ops.cpu_on) {
+		pr_err("no cpu_on method, not booting CPU%d\n", cpu);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int cpu_psci_cpu_boot(unsigned int cpu)
+{
+	int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa(secondary_entry));
+	if (err)
+		pr_err("failed to boot CPU%d (%d)\n", cpu, err);
+
+	return err;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static int cpu_psci_cpu_disable(unsigned int cpu)
+{
+	/* Fail early if we don't have CPU_OFF support */
+	if (!psci_ops.cpu_off)
+		return -EOPNOTSUPP;
+	return 0;
+}
+
+static void cpu_psci_cpu_die(unsigned int cpu)
+{
+	int ret;
+	/*
+	 * There are no known implementations of PSCI actually using the
+	 * power state field, pass a sensible default for now.
+	 */
+	struct psci_power_state state = {
+		.type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
+	};
+
+	ret = psci_ops.cpu_off(state);
+
+	pr_crit("unable to power off CPU%u (%d)\n", cpu, ret);
+}
+
+static int cpu_psci_cpu_kill(unsigned int cpu)
+{
+	int err, i;
+
+	if (!psci_ops.affinity_info)
+		return 1;
+	/*
+	 * cpu_kill could race with cpu_die and we can
+	 * potentially end up declaring this cpu undead
+	 * while it is dying. So, try again a few times.
+	 */
+
+	for (i = 0; i < 10; i++) {
+		err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
+		if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) {
+			pr_info("CPU%d killed.\n", cpu);
+			return 1;
+		}
+
+		msleep(10);
+		pr_info("Retrying again to check for CPU kill\n");
+	}
+
+	pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n",
+			cpu, err);
+	/* Make op_cpu_kill() fail. */
+	return 0;
+}
+#endif
+#endif
+
+static int psci_suspend_finisher(unsigned long index)
+{
+	struct psci_power_state *state = __get_cpu_var(psci_power_state);
+
+	return psci_ops.cpu_suspend(state[index - 1],
+				    virt_to_phys(cpu_resume));
+}
+
+/**
+ * Ideally, we hope that PSCI framework cover the all power states, but it
+ * is not correspond on some platforms. Below function supports extra power
+ * state that PSCI cannot be handled.
+ * ID : indicates system power mode. if id is not 0, it is system power mode(SICD).
+ * TYPE : None
+ * AFFINITY_LEVEL : powre off scope of power mode. (0 -> core, 1 -> cluster, 3 -> system)
+ */
+static int psci_suspend_customized_finisher(unsigned long index)
+{
+	struct psci_power_state state = {
+			.id = 0,
+			.type = 0,
+			.affinity_level = 0,
+	};
+
+	switch (index) {
+	case PSCI_CLUSTER_SLEEP:
+		state.affinity_level = 1;
+		break;
+	case PSCI_SYSTEM_IDLE:
+		state.id = 1;
+		break;
+	case PSCI_SYSTEM_IDLE_CLUSTER_SLEEP:
+		state.id = 1;
+		state.affinity_level = 1;
+		break;
+	case PSCI_SYSTEM_CP_CALL:
+		state.affinity_level = 2;
+		break;
+	case PSCI_SYSTEM_SLEEP:
+		state.affinity_level = 3;
+		break;
+	default:
+		panic("Unsupported psci state, index = %ld\n", index);
+		break;
+	};
+
+	return psci_ops.cpu_suspend(state, virt_to_phys(cpu_resume));
+}
+
+static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
+{
+	int ret;
+	struct psci_power_state *state = __get_cpu_var(psci_power_state);
+
+	/*
+	 * idle state index 0 corresponds to wfi, should never be called
+	 * from the cpu_suspend operations
+	 */
+	if (WARN_ON_ONCE(!index))
+		return -EINVAL;
+
+	if (unlikely(index >= PSCI_UNUSED_INDEX))
+		return __cpu_suspend(index, psci_suspend_customized_finisher);
+
+	if (state[index - 1].type == PSCI_POWER_STATE_TYPE_STANDBY)
+		ret = psci_ops.cpu_suspend(state[index - 1], 0);
+	else
+		ret = __cpu_suspend(index, psci_suspend_finisher);
+
+	return ret;
+}
+
+const struct cpu_operations cpu_psci_ops = {
+	.name		= "psci",
+#ifdef CONFIG_CPU_IDLE
+	.cpu_init_idle	= cpu_psci_cpu_init_idle,
+#endif
+#ifdef CONFIG_ARM64_CPU_SUSPEND
+	.cpu_suspend	= cpu_psci_cpu_suspend,
+#endif
+#ifdef CONFIG_SMP
+	.cpu_init	= cpu_psci_cpu_init,
+	.cpu_prepare	= cpu_psci_cpu_prepare,
+	.cpu_boot	= cpu_psci_cpu_boot,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_disable	= cpu_psci_cpu_disable,
+	.cpu_die	= cpu_psci_cpu_die,
+	.cpu_kill	= cpu_psci_cpu_kill,
+#endif
+#endif
+};
+

arch/arm64/kernel/return_address.c

@@ -0,0 +1,54 @@
+/*
+ * arch/arm64/kernel/return_address.c
+ *
+ * Copyright (C) 2013 Linaro Limited
+ * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/export.h>
+#include <linux/ftrace.h>
+
+#include <asm/stacktrace.h>
+
+struct return_address_data {
+	unsigned int level;
+	void *addr;
+};
+
+static int save_return_addr(struct stackframe *frame, void *d)
+{
+	struct return_address_data *data = d;
+
+	if (!data->level) {
+		data->addr = (void *)frame->pc;
+		return 1;
+	} else {
+		--data->level;
+		return 0;
+	}
+}
+
+void *return_address(unsigned int level)
+{
+	struct return_address_data data;
+	struct stackframe frame;
+
+	data.level = level + 2;
+	data.addr = NULL;
+
+	frame.fp = (unsigned long)__builtin_frame_address(0);
+	frame.sp = current_stack_pointer;
+	frame.pc = (unsigned long)return_address; /* dummy */
+
+	walk_stackframe(&frame, save_return_addr, &data);
+
+	if (!data.level)
+		return data.addr;
+	else
+		return NULL;
+}
+EXPORT_SYMBOL_GPL(return_address);

arch/arm64/kernel/rkp_entry.S

@@ -0,0 +1,27 @@
+/*
+ *  Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+
+#include <linux/linkage.h>
+#include <linux/rkp_entry.h>
+
+ENTRY(rkp_call)
+	hvc	#0
+	ret
+ENDPROC(rkp_call)

arch/arm64/kernel/setup.c

@@ -0,0 +1,598 @@
+/*
+ * Based on arch/arm/kernel/setup.c
+ *
+ * Copyright (C) 1995-2001 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/stddef.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/utsname.h>
+#include <linux/initrd.h>
+#include <linux/console.h>
+#include <linux/cache.h>
+#include <linux/bootmem.h>
+#include <linux/seq_file.h>
+#include <linux/screen_info.h>
+#include <linux/init.h>
+#include <linux/kexec.h>
+#include <linux/crash_dump.h>
+#include <linux/root_dev.h>
+#include <linux/clk-provider.h>
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/smp.h>
+#include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/memblock.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+#include <linux/efi.h>
+#include <linux/personality.h>
+
+#include <asm/fixmap.h>
+#include <asm/cpu.h>
+#include <asm/cputype.h>
+#include <asm/elf.h>
+#include <asm/cputable.h>
+#include <asm/cpufeature.h>
+#include <asm/cpu_ops.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/smp_plat.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/traps.h>
+#include <asm/memblock.h>
+#include <asm/psci.h>
+#include <asm/efi.h>
+
+#if defined(CONFIG_ECT)
+#include <soc/samsung/ect_parser.h>
+#endif
+
+unsigned int processor_id;
+EXPORT_SYMBOL(processor_id);
+
+unsigned long elf_hwcap __read_mostly;
+EXPORT_SYMBOL_GPL(elf_hwcap);
+
+#ifdef CONFIG_COMPAT
+#define COMPAT_ELF_HWCAP_DEFAULT	\
+				(COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
+				 COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
+				 COMPAT_HWCAP_TLS|COMPAT_HWCAP_VFP|\
+				 COMPAT_HWCAP_VFPv3|COMPAT_HWCAP_VFPv4|\
+				 COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV|\
+				 COMPAT_HWCAP_LPAE)
+unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
+unsigned int compat_elf_hwcap2 __read_mostly;
+#endif
+
+DECLARE_BITMAP(cpu_hwcaps, NCAPS);
+
+static const char *cpu_name;
+phys_addr_t __fdt_pointer __initdata;
+
+/*
+ * Standard memory resources
+ */
+static struct resource mem_res[] = {
+	{
+		.name = "Kernel code",
+		.start = 0,
+		.end = 0,
+		.flags = IORESOURCE_MEM
+	},
+	{
+		.name = "Kernel data",
+		.start = 0,
+		.end = 0,
+		.flags = IORESOURCE_MEM
+	}
+};
+
+#define kernel_code mem_res[0]
+#define kernel_data mem_res[1]
+
+void __init early_print(const char *str, ...)
+{
+	char buf[256];
+	va_list ap;
+
+	va_start(ap, str);
+	vsnprintf(buf, sizeof(buf), str, ap);
+	va_end(ap);
+
+	printk("%s", buf);
+}
+
+void __init smp_setup_processor_id(void)
+{
+	/*
+	 * clear __my_cpu_offset on boot CPU to avoid hang caused by
+	 * using percpu variable early, for example, lockdep will
+	 * access percpu variable inside lock_release
+	 */
+	set_my_cpu_offset(0);
+}
+
+#if defined(CONFIG_ECT)
+int __init early_init_dt_scan_ect(unsigned long node, const char *uname,
+		int depth, void *data)
+{
+	int address = 0, size = 0;
+	const __be32 *paddr, *psize;
+
+	if (depth != 1 || (strcmp(uname, "ect") != 0))
+		return 0;
+
+	paddr = of_get_flat_dt_prop(node, "parameter_address", &address);
+	if (paddr == NULL)
+		return 0;
+
+	psize = of_get_flat_dt_prop(node, "parameter_size", &size);
+	if (psize == NULL)
+		return -1;
+
+	pr_info("[ECT] Address %x, Size %x\b", be32_to_cpu(*paddr), be32_to_cpu(*psize));
+	memblock_reserve(be32_to_cpu(*paddr), be32_to_cpu(*psize));
+	ect_init(be32_to_cpu(*paddr), be32_to_cpu(*psize));
+
+	return 1;
+}
+#endif
+
+bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+	return phys_id == cpu_logical_map(cpu);
+}
+
+struct mpidr_hash mpidr_hash;
+#ifdef CONFIG_SMP
+/**
+ * smp_build_mpidr_hash - Pre-compute shifts required at each affinity
+ *			  level in order to build a linear index from an
+ *			  MPIDR value. Resulting algorithm is a collision
+ *			  free hash carried out through shifting and ORing
+ */
+static void __init smp_build_mpidr_hash(void)
+{
+	u32 i, affinity, fs[4], bits[4], ls;
+	u64 mask = 0;
+	/*
+	 * Pre-scan the list of MPIDRS and filter out bits that do
+	 * not contribute to affinity levels, ie they never toggle.
+	 */
+	for_each_possible_cpu(i)
+		mask |= (cpu_logical_map(i) ^ cpu_logical_map(0));
+	pr_debug("mask of set bits %#llx\n", mask);
+	/*
+	 * Find and stash the last and first bit set at all affinity levels to
+	 * check how many bits are required to represent them.
+	 */
+	for (i = 0; i < 4; i++) {
+		affinity = MPIDR_AFFINITY_LEVEL(mask, i);
+		/*
+		 * Find the MSB bit and LSB bits position
+		 * to determine how many bits are required
+		 * to express the affinity level.
+		 */
+		ls = fls(affinity);
+		fs[i] = affinity ? ffs(affinity) - 1 : 0;
+		bits[i] = ls - fs[i];
+	}
+	/*
+	 * An index can be created from the MPIDR_EL1 by isolating the
+	 * significant bits at each affinity level and by shifting
+	 * them in order to compress the 32 bits values space to a
+	 * compressed set of values. This is equivalent to hashing
+	 * the MPIDR_EL1 through shifting and ORing. It is a collision free
+	 * hash though not minimal since some levels might contain a number
+	 * of CPUs that is not an exact power of 2 and their bit
+	 * representation might contain holes, eg MPIDR_EL1[7:0] = {0x2, 0x80}.
+	 */
+	mpidr_hash.shift_aff[0] = MPIDR_LEVEL_SHIFT(0) + fs[0];
+	mpidr_hash.shift_aff[1] = MPIDR_LEVEL_SHIFT(1) + fs[1] - bits[0];
+	mpidr_hash.shift_aff[2] = MPIDR_LEVEL_SHIFT(2) + fs[2] -
+						(bits[1] + bits[0]);
+	mpidr_hash.shift_aff[3] = MPIDR_LEVEL_SHIFT(3) +
+				  fs[3] - (bits[2] + bits[1] + bits[0]);
+	mpidr_hash.mask = mask;
+	mpidr_hash.bits = bits[3] + bits[2] + bits[1] + bits[0];
+	pr_debug("MPIDR hash: aff0[%u] aff1[%u] aff2[%u] aff3[%u] mask[%#llx] bits[%u]\n",
+		mpidr_hash.shift_aff[0],
+		mpidr_hash.shift_aff[1],
+		mpidr_hash.shift_aff[2],
+		mpidr_hash.shift_aff[3],
+		mpidr_hash.mask,
+		mpidr_hash.bits);
+	/*
+	 * 4x is an arbitrary value used to warn on a hash table much bigger
+	 * than expected on most systems.
+	 */
+	if (mpidr_hash_size() > 4 * num_possible_cpus())
+		pr_warn("Large number of MPIDR hash buckets detected\n");
+	__flush_dcache_area(&mpidr_hash, sizeof(struct mpidr_hash));
+}
+#endif
+
+static void __init setup_processor(void)
+{
+	struct cpu_info *cpu_info;
+	u64 features, block;
+	u32 cwg;
+	int cls;
+
+	cpu_info = lookup_processor_type(read_cpuid_id());
+	if (!cpu_info) {
+		printk("CPU configuration botched (ID %08x), unable to continue.\n",
+		       read_cpuid_id());
+		while (1);
+	}
+
+	cpu_name = cpu_info->cpu_name;
+
+	printk("CPU: %s [%08x] revision %d\n",
+	       cpu_name, read_cpuid_id(), read_cpuid_id() & 15);
+
+	sprintf(init_utsname()->machine, ELF_PLATFORM);
+	elf_hwcap = 0;
+
+	cpuinfo_store_boot_cpu();
+
+	/*
+	 * Check for sane CTR_EL0.CWG value.
+	 */
+	cwg = cache_type_cwg();
+	cls = cache_line_size();
+	if (!cwg)
+		pr_warn("No Cache Writeback Granule information, assuming cache line size %d\n",
+			cls);
+	if (L1_CACHE_BYTES < cls)
+		pr_warn("L1_CACHE_BYTES smaller than the Cache Writeback Granule (%d < %d)\n",
+			L1_CACHE_BYTES, cls);
+
+	/*
+	 * ID_AA64ISAR0_EL1 contains 4-bit wide signed feature blocks.
+	 * The blocks we test below represent incremental functionality
+	 * for non-negative values. Negative values are reserved.
+	 */
+	features = read_cpuid(ID_AA64ISAR0_EL1);
+	block = (features >> 4) & 0xf;
+	if (!(block & 0x8)) {
+		switch (block) {
+		default:
+		case 2:
+			elf_hwcap |= HWCAP_PMULL;
+		case 1:
+			elf_hwcap |= HWCAP_AES;
+		case 0:
+			break;
+		}
+	}
+
+	block = (features >> 8) & 0xf;
+	if (block && !(block & 0x8))
+		elf_hwcap |= HWCAP_SHA1;
+
+	block = (features >> 12) & 0xf;
+	if (block && !(block & 0x8))
+		elf_hwcap |= HWCAP_SHA2;
+
+	block = (features >> 16) & 0xf;
+	if (block && !(block & 0x8))
+		elf_hwcap |= HWCAP_CRC32;
+
+#ifdef CONFIG_COMPAT
+	/*
+	 * ID_ISAR5_EL1 carries similar information as above, but pertaining to
+	 * the Aarch32 32-bit execution state.
+	 */
+	features = read_cpuid(ID_ISAR5_EL1);
+	block = (features >> 4) & 0xf;
+	if (!(block & 0x8)) {
+		switch (block) {
+		default:
+		case 2:
+			compat_elf_hwcap2 |= COMPAT_HWCAP2_PMULL;
+		case 1:
+			compat_elf_hwcap2 |= COMPAT_HWCAP2_AES;
+		case 0:
+			break;
+		}
+	}
+
+	block = (features >> 8) & 0xf;
+	if (block && !(block & 0x8))
+		compat_elf_hwcap2 |= COMPAT_HWCAP2_SHA1;
+
+	block = (features >> 12) & 0xf;
+	if (block && !(block & 0x8))
+		compat_elf_hwcap2 |= COMPAT_HWCAP2_SHA2;
+
+	block = (features >> 16) & 0xf;
+	if (block && !(block & 0x8))
+		compat_elf_hwcap2 |= COMPAT_HWCAP2_CRC32;
+#endif
+}
+
+static void __init setup_machine_fdt(phys_addr_t dt_phys)
+{
+	if (!dt_phys || !early_init_dt_scan(phys_to_virt(dt_phys))) {
+		early_print("\n"
+			"Error: invalid device tree blob at physical address 0x%p (virtual address 0x%p)\n"
+			"The dtb must be 8-byte aligned and passed in the first 512MB of memory\n"
+			"\nPlease check your bootloader.\n",
+			dt_phys, phys_to_virt(dt_phys));
+
+		while (true)
+			cpu_relax();
+	}
+
+	dump_stack_set_arch_desc("%s (DT)", of_flat_dt_get_machine_name());
+
+#if defined(CONFIG_ECT)
+	/* Scan dvfs paramter information, address that loaded on DRAM and size */
+	of_scan_flat_dt(early_init_dt_scan_ect, NULL);
+#endif
+}
+
+/*
+ * Limit the memory size that was specified via FDT.
+ */
+static int __init early_mem(char *p)
+{
+	phys_addr_t limit;
+
+	if (!p)
+		return 1;
+
+	limit = memparse(p, &p) & PAGE_MASK;
+	pr_notice("Memory limited to %lldMB\n", limit >> 20);
+
+	memblock_enforce_memory_limit(limit);
+
+	return 0;
+}
+early_param("mem", early_mem);
+
+static void __init request_standard_resources(void)
+{
+	struct memblock_region *region;
+	struct resource *res;
+
+	kernel_code.start   = virt_to_phys(_text);
+	kernel_code.end     = virt_to_phys(_etext - 1);
+	kernel_data.start   = virt_to_phys(_sdata);
+	kernel_data.end     = virt_to_phys(_end - 1);
+
+	for_each_memblock(memory, region) {
+		res = alloc_bootmem_low(sizeof(*res));
+		res->name  = "System RAM";
+		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
+		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
+		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+
+		request_resource(&iomem_resource, res);
+
+		if (kernel_code.start >= res->start &&
+		    kernel_code.end <= res->end)
+			request_resource(res, &kernel_code);
+		if (kernel_data.start >= res->start &&
+		    kernel_data.end <= res->end)
+			request_resource(res, &kernel_data);
+	}
+}
+
+u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
+
+void __init setup_arch(char **cmdline_p)
+{
+	setup_processor();
+
+	setup_machine_fdt(__fdt_pointer);
+
+	init_mm.start_code = (unsigned long) _text;
+	init_mm.end_code   = (unsigned long) _etext;
+	init_mm.end_data   = (unsigned long) _edata;
+	init_mm.brk	   = (unsigned long) _end;
+
+	*cmdline_p = boot_command_line;
+
+	early_ioremap_init();
+
+	parse_early_param();
+
+	/*
+	 *  Unmask asynchronous aborts after bringing up possible earlycon.
+	 * (Report possible System Errors once we can report this occurred)
+	 */
+	local_async_enable();
+
+	efi_init();
+	arm64_memblock_init();
+
+	paging_init();
+	request_standard_resources();
+
+	efi_idmap_init();
+	early_ioremap_reset();
+
+	unflatten_device_tree();
+
+	psci_init();
+
+	cpu_logical_map(0) = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
+	cpu_read_bootcpu_ops();
+#ifdef CONFIG_SMP
+	smp_init_cpus();
+	smp_build_mpidr_hash();
+#endif
+
+#ifdef CONFIG_VT
+#if defined(CONFIG_VGA_CONSOLE)
+	conswitchp = &vga_con;
+#elif defined(CONFIG_DUMMY_CONSOLE)
+	conswitchp = &dummy_con;
+#endif
+#endif
+}
+
+static int __init arm64_device_init(void)
+{
+	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
+	return 0;
+}
+arch_initcall_sync(arm64_device_init);
+
+static int __init topology_init(void)
+{
+	int i;
+
+	for_each_possible_cpu(i) {
+		struct cpu *cpu = &per_cpu(cpu_data.cpu, i);
+		cpu->hotpluggable = 1;
+		register_cpu(cpu, i);
+	}
+
+	return 0;
+}
+subsys_initcall(topology_init);
+
+static const char *hwcap_str[] = {
+	"fp",
+	"asimd",
+	"evtstrm",
+	"aes",
+	"pmull",
+	"sha1",
+	"sha2",
+	"crc32",
+	NULL
+};
+
+#ifdef CONFIG_COMPAT
+static const char *compat_hwcap_str[] = {
+	"swp",
+	"half",
+	"thumb",
+	"26bit",
+	"fastmult",
+	"fpa",
+	"vfp",
+	"edsp",
+	"java",
+	"iwmmxt",
+	"crunch",
+	"thumbee",
+	"neon",
+	"vfpv3",
+	"vfpv3d16",
+	"tls",
+	"vfpv4",
+	"idiva",
+	"idivt",
+	"vfpd32",
+	"lpae",
+	"evtstrm"
+};
+
+static const char *compat_hwcap2_str[] = {
+	"aes",
+	"pmull",
+	"sha1",
+	"sha2",
+	"crc32",
+	NULL
+};
+#endif /* CONFIG_COMPAT */
+
+static int c_show(struct seq_file *m, void *v)
+{
+	int i, j;
+
+	for_each_online_cpu(i) {
+		struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
+		u32 midr = cpuinfo->reg_midr;
+
+		/*
+		 * glibc reads /proc/cpuinfo to determine the number of
+		 * online processors, looking for lines beginning with
+		 * "processor".  Give glibc what it expects.
+		 */
+#ifdef CONFIG_SMP
+		seq_printf(m, "processor\t: %d\n", i);
+#endif
+
+		/*
+		 * Dump out the common processor features in a single line.
+		 * Userspace should read the hwcaps with getauxval(AT_HWCAP)
+		 * rather than attempting to parse this, but there's a body of
+		 * software which does already (at least for 32-bit).
+		 */
+		seq_puts(m, "Features\t:");
+		if (personality(current->personality) == PER_LINUX32) {
+#ifdef CONFIG_COMPAT
+			for (j = 0; compat_hwcap_str[j]; j++)
+				if (compat_elf_hwcap & (1 << j))
+					seq_printf(m, " %s", compat_hwcap_str[j]);
+
+			for (j = 0; compat_hwcap2_str[j]; j++)
+				if (compat_elf_hwcap2 & (1 << j))
+					seq_printf(m, " %s", compat_hwcap2_str[j]);
+#endif /* CONFIG_COMPAT */
+		} else {
+			for (j = 0; hwcap_str[j]; j++)
+				if (elf_hwcap & (1 << j))
+					seq_printf(m, " %s", hwcap_str[j]);
+		}
+		seq_puts(m, "\n");
+
+		seq_printf(m, "CPU implementer\t: 0x%02x\n",
+			   MIDR_IMPLEMENTOR(midr));
+		seq_printf(m, "CPU architecture: 8\n");
+		seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
+		seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
+		seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
+	}
+
+	return 0;
+}
+
+static void *c_start(struct seq_file *m, loff_t *pos)
+{
+	return *pos < 1 ? (void *)1 : NULL;
+}
+
+static void *c_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	++*pos;
+	return NULL;
+}
+
+static void c_stop(struct seq_file *m, void *v)
+{
+}
+
+const struct seq_operations cpuinfo_op = {
+	.start	= c_start,
+	.next	= c_next,
+	.stop	= c_stop,
+	.show	= c_show
+};

arch/arm64/kernel/signal.c

@@ -0,0 +1,423 @@
+/*
+ * Based on arch/arm/kernel/signal.c
+ *
+ * Copyright (C) 1995-2009 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/compat.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/personality.h>
+#include <linux/freezer.h>
+#include <linux/uaccess.h>
+#include <linux/tracehook.h>
+#include <linux/ratelimit.h>
+
+#include <asm/debug-monitors.h>
+#include <asm/elf.h>
+#include <asm/cacheflush.h>
+#include <asm/ucontext.h>
+#include <asm/unistd.h>
+#include <asm/fpsimd.h>
+#include <asm/signal32.h>
+#include <asm/vdso.h>
+
+/*
+ * Do a signal return; undo the signal stack. These are aligned to 128-bit.
+ */
+struct rt_sigframe {
+	struct siginfo info;
+	struct ucontext uc;
+	u64 fp;
+	u64 lr;
+};
+
+static int preserve_fpsimd_context(struct fpsimd_context __user *ctx)
+{
+	struct fpsimd_state *fpsimd = &current->thread.fpsimd_state;
+	int err;
+
+	/* dump the hardware registers to the fpsimd_state structure */
+	fpsimd_preserve_current_state();
+
+	/* copy the FP and status/control registers */
+	err = __copy_to_user(ctx->vregs, fpsimd->vregs, sizeof(fpsimd->vregs));
+	__put_user_error(fpsimd->fpsr, &ctx->fpsr, err);
+	__put_user_error(fpsimd->fpcr, &ctx->fpcr, err);
+
+	/* copy the magic/size information */
+	__put_user_error(FPSIMD_MAGIC, &ctx->head.magic, err);
+	__put_user_error(sizeof(struct fpsimd_context), &ctx->head.size, err);
+
+	return err ? -EFAULT : 0;
+}
+
+static int restore_fpsimd_context(struct fpsimd_context __user *ctx)
+{
+	struct fpsimd_state fpsimd;
+	__u32 magic, size;
+	int err = 0;
+
+	/* check the magic/size information */
+	__get_user_error(magic, &ctx->head.magic, err);
+	__get_user_error(size, &ctx->head.size, err);
+	if (err)
+		return -EFAULT;
+	if (magic != FPSIMD_MAGIC || size != sizeof(struct fpsimd_context))
+		return -EINVAL;
+
+	/* copy the FP and status/control registers */
+	err = __copy_from_user(fpsimd.vregs, ctx->vregs,
+			       sizeof(fpsimd.vregs));
+	__get_user_error(fpsimd.fpsr, &ctx->fpsr, err);
+	__get_user_error(fpsimd.fpcr, &ctx->fpcr, err);
+
+	/* load the hardware registers from the fpsimd_state structure */
+	if (!err)
+		fpsimd_update_current_state(&fpsimd);
+
+	return err ? -EFAULT : 0;
+}
+
+static int restore_sigframe(struct pt_regs *regs,
+			    struct rt_sigframe __user *sf)
+{
+	sigset_t set;
+	int i, err;
+	void *aux = sf->uc.uc_mcontext.__reserved;
+
+	err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
+	if (err == 0)
+		set_current_blocked(&set);
+
+	for (i = 0; i < 31; i++)
+		__get_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i],
+				 err);
+	__get_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err);
+	__get_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err);
+	__get_user_error(regs->pstate, &sf->uc.uc_mcontext.pstate, err);
+
+	/*
+	 * Avoid sys_rt_sigreturn() restarting.
+	 */
+	regs->syscallno = ~0UL;
+
+	err |= !valid_user_regs(&regs->user_regs);
+
+	if (err == 0) {
+		struct fpsimd_context *fpsimd_ctx =
+			container_of(aux, struct fpsimd_context, head);
+		err |= restore_fpsimd_context(fpsimd_ctx);
+	}
+
+	return err;
+}
+
+asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+{
+	struct rt_sigframe __user *frame;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+	/*
+	 * Since we stacked the signal on a 128-bit boundary, then 'sp' should
+	 * be word aligned here.
+	 */
+	if (regs->sp & 15)
+		goto badframe;
+
+	frame = (struct rt_sigframe __user *)regs->sp;
+
+	if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
+		goto badframe;
+
+	if (restore_sigframe(regs, frame))
+		goto badframe;
+
+	if (restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return regs->regs[0];
+
+badframe:
+	if (show_unhandled_signals)
+		pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
+				    current->comm, task_pid_nr(current), __func__,
+				    regs->pc, regs->sp);
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+static int setup_sigframe(struct rt_sigframe __user *sf,
+			  struct pt_regs *regs, sigset_t *set)
+{
+	int i, err = 0;
+	void *aux = sf->uc.uc_mcontext.__reserved;
+	struct _aarch64_ctx *end;
+
+	/* set up the stack frame for unwinding */
+	__put_user_error(regs->regs[29], &sf->fp, err);
+	__put_user_error(regs->regs[30], &sf->lr, err);
+
+	for (i = 0; i < 31; i++)
+		__put_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i],
+				 err);
+	__put_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err);
+	__put_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err);
+	__put_user_error(regs->pstate, &sf->uc.uc_mcontext.pstate, err);
+
+	__put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
+
+	err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
+
+	if (err == 0) {
+		struct fpsimd_context *fpsimd_ctx =
+			container_of(aux, struct fpsimd_context, head);
+		err |= preserve_fpsimd_context(fpsimd_ctx);
+		aux += sizeof(*fpsimd_ctx);
+	}
+
+	/* fault information, if valid */
+	if (current->thread.fault_code) {
+		struct esr_context *esr_ctx =
+			container_of(aux, struct esr_context, head);
+		__put_user_error(ESR_MAGIC, &esr_ctx->head.magic, err);
+		__put_user_error(sizeof(*esr_ctx), &esr_ctx->head.size, err);
+		__put_user_error(current->thread.fault_code, &esr_ctx->esr, err);
+		aux += sizeof(*esr_ctx);
+	}
+
+	/* set the "end" magic */
+	end = aux;
+	__put_user_error(0, &end->magic, err);
+	__put_user_error(0, &end->size, err);
+
+	return err;
+}
+
+static struct rt_sigframe __user *get_sigframe(struct ksignal *ksig,
+					       struct pt_regs *regs)
+{
+	unsigned long sp, sp_top;
+	struct rt_sigframe __user *frame;
+
+	sp = sp_top = sigsp(regs->sp, ksig);
+
+	sp = (sp - sizeof(struct rt_sigframe)) & ~15;
+	frame = (struct rt_sigframe __user *)sp;
+
+	/*
+	 * Check that we can actually write to the signal frame.
+	 */
+	if (!access_ok(VERIFY_WRITE, frame, sp_top - sp))
+		frame = NULL;
+
+	return frame;
+}
+
+static void setup_return(struct pt_regs *regs, struct k_sigaction *ka,
+			 void __user *frame, int usig)
+{
+	__sigrestore_t sigtramp;
+
+	regs->regs[0] = usig;
+	regs->sp = (unsigned long)frame;
+	regs->regs[29] = regs->sp + offsetof(struct rt_sigframe, fp);
+	regs->pc = (unsigned long)ka->sa.sa_handler;
+
+	if (ka->sa.sa_flags & SA_RESTORER)
+		sigtramp = ka->sa.sa_restorer;
+	else
+		sigtramp = VDSO_SYMBOL(current->mm->context.vdso, sigtramp);
+
+	regs->regs[30] = (unsigned long)sigtramp;
+}
+
+static int setup_rt_frame(int usig, struct ksignal *ksig, sigset_t *set,
+			  struct pt_regs *regs)
+{
+	struct rt_sigframe __user *frame;
+	int err = 0;
+
+	frame = get_sigframe(ksig, regs);
+	if (!frame)
+		return 1;
+
+	__put_user_error(0, &frame->uc.uc_flags, err);
+	__put_user_error(NULL, &frame->uc.uc_link, err);
+
+	err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
+	err |= setup_sigframe(frame, regs, set);
+	if (err == 0) {
+		setup_return(regs, &ksig->ka, frame, usig);
+		if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
+			err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+			regs->regs[1] = (unsigned long)&frame->info;
+			regs->regs[2] = (unsigned long)&frame->uc;
+		}
+	}
+
+	return err;
+}
+
+static void setup_restart_syscall(struct pt_regs *regs)
+{
+	if (is_compat_task())
+		compat_setup_restart_syscall(regs);
+	else
+		regs->regs[8] = __NR_restart_syscall;
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+	struct thread_info *thread = current_thread_info();
+	struct task_struct *tsk = current;
+	sigset_t *oldset = sigmask_to_save();
+	int usig = ksig->sig;
+	int ret;
+
+	/*
+	 * translate the signal
+	 */
+	if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
+		usig = thread->exec_domain->signal_invmap[usig];
+
+	/*
+	 * Set up the stack frame
+	 */
+	if (is_compat_task()) {
+		if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+			ret = compat_setup_rt_frame(usig, ksig, oldset, regs);
+		else
+			ret = compat_setup_frame(usig, ksig, oldset, regs);
+	} else {
+		ret = setup_rt_frame(usig, ksig, oldset, regs);
+	}
+
+	/*
+	 * Check that the resulting registers are actually sane.
+	 */
+	ret |= !valid_user_regs(&regs->user_regs);
+
+	/*
+	 * Fast forward the stepping logic so we step into the signal
+	 * handler.
+	 */
+	if (!ret)
+		user_fastforward_single_step(tsk);
+
+	signal_setup_done(ret, ksig, 0);
+}
+
+/*
+ * Note that 'init' is a special process: it doesn't get signals it doesn't
+ * want to handle. Thus you cannot kill init even with a SIGKILL even by
+ * mistake.
+ *
+ * Note that we go through the signals twice: once to check the signals that
+ * the kernel can handle, and then we build all the user-level signal handling
+ * stack-frames in one go after that.
+ */
+static void do_signal(struct pt_regs *regs)
+{
+	unsigned long continue_addr = 0, restart_addr = 0;
+	int retval = 0;
+	int syscall = (int)regs->syscallno;
+	struct ksignal ksig;
+
+	/*
+	 * If we were from a system call, check for system call restarting...
+	 */
+	if (syscall >= 0) {
+		continue_addr = regs->pc;
+		restart_addr = continue_addr - (compat_thumb_mode(regs) ? 2 : 4);
+		retval = regs->regs[0];
+
+		/*
+		 * Avoid additional syscall restarting via ret_to_user.
+		 */
+		regs->syscallno = ~0UL;
+
+		/*
+		 * Prepare for system call restart. We do this here so that a
+		 * debugger will see the already changed PC.
+		 */
+		switch (retval) {
+		case -ERESTARTNOHAND:
+		case -ERESTARTSYS:
+		case -ERESTARTNOINTR:
+		case -ERESTART_RESTARTBLOCK:
+			regs->regs[0] = regs->orig_x0;
+			regs->pc = restart_addr;
+			break;
+		}
+	}
+
+	/*
+	 * Get the signal to deliver. When running under ptrace, at this point
+	 * the debugger may change all of our registers.
+	 */
+	if (get_signal(&ksig)) {
+		/*
+		 * Depending on the signal settings, we may need to revert the
+		 * decision to restart the system call, but skip this if a
+		 * debugger has chosen to restart at a different PC.
+		 */
+		if (regs->pc == restart_addr &&
+		    (retval == -ERESTARTNOHAND ||
+		     retval == -ERESTART_RESTARTBLOCK ||
+		     (retval == -ERESTARTSYS &&
+		      !(ksig.ka.sa.sa_flags & SA_RESTART)))) {
+			regs->regs[0] = -EINTR;
+			regs->pc = continue_addr;
+		}
+
+		handle_signal(&ksig, regs);
+		return;
+	}
+
+	/*
+	 * Handle restarting a different system call. As above, if a debugger
+	 * has chosen to restart at a different PC, ignore the restart.
+	 */
+	if (syscall >= 0 && regs->pc == restart_addr) {
+		if (retval == -ERESTART_RESTARTBLOCK)
+			setup_restart_syscall(regs);
+		user_rewind_single_step(current);
+	}
+
+	restore_saved_sigmask();
+}
+
+asmlinkage void do_notify_resume(struct pt_regs *regs,
+				 unsigned int thread_flags)
+{
+	if (thread_flags & _TIF_SIGPENDING)
+		do_signal(regs);
+
+	if (thread_flags & _TIF_NOTIFY_RESUME) {
+		clear_thread_flag(TIF_NOTIFY_RESUME);
+		tracehook_notify_resume(regs);
+	}
+
+	if (thread_flags & _TIF_FOREIGN_FPSTATE)
+		fpsimd_restore_current_state();
+
+}

arch/arm64/kernel/signal32.c

@@ -0,0 +1,577 @@
+/*
+ * Based on arch/arm/kernel/signal.c
+ *
+ * Copyright (C) 1995-2009 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ * Modified by Will Deacon <will.deacon@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/compat.h>
+#include <linux/signal.h>
+#include <linux/syscalls.h>
+#include <linux/ratelimit.h>
+
+#include <asm/esr.h>
+#include <asm/fpsimd.h>
+#include <asm/signal32.h>
+#include <asm/uaccess.h>
+#include <asm/unistd.h>
+
+struct compat_sigcontext {
+	/* We always set these two fields to 0 */
+	compat_ulong_t			trap_no;
+	compat_ulong_t			error_code;
+
+	compat_ulong_t			oldmask;
+	compat_ulong_t			arm_r0;
+	compat_ulong_t			arm_r1;
+	compat_ulong_t			arm_r2;
+	compat_ulong_t			arm_r3;
+	compat_ulong_t			arm_r4;
+	compat_ulong_t			arm_r5;
+	compat_ulong_t			arm_r6;
+	compat_ulong_t			arm_r7;
+	compat_ulong_t			arm_r8;
+	compat_ulong_t			arm_r9;
+	compat_ulong_t			arm_r10;
+	compat_ulong_t			arm_fp;
+	compat_ulong_t			arm_ip;
+	compat_ulong_t			arm_sp;
+	compat_ulong_t			arm_lr;
+	compat_ulong_t			arm_pc;
+	compat_ulong_t			arm_cpsr;
+	compat_ulong_t			fault_address;
+};
+
+struct compat_ucontext {
+	compat_ulong_t			uc_flags;
+	compat_uptr_t			uc_link;
+	compat_stack_t			uc_stack;
+	struct compat_sigcontext	uc_mcontext;
+	compat_sigset_t			uc_sigmask;
+	int		__unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
+	compat_ulong_t	uc_regspace[128] __attribute__((__aligned__(8)));
+};
+
+struct compat_vfp_sigframe {
+	compat_ulong_t	magic;
+	compat_ulong_t	size;
+	struct compat_user_vfp {
+		compat_u64	fpregs[32];
+		compat_ulong_t	fpscr;
+	} ufp;
+	struct compat_user_vfp_exc {
+		compat_ulong_t	fpexc;
+		compat_ulong_t	fpinst;
+		compat_ulong_t	fpinst2;
+	} ufp_exc;
+} __attribute__((__aligned__(8)));
+
+#define VFP_MAGIC		0x56465001
+#define VFP_STORAGE_SIZE	sizeof(struct compat_vfp_sigframe)
+
+#define FSR_WRITE_SHIFT		(11)
+
+struct compat_aux_sigframe {
+	struct compat_vfp_sigframe	vfp;
+
+	/* Something that isn't a valid magic number for any coprocessor.  */
+	unsigned long			end_magic;
+} __attribute__((__aligned__(8)));
+
+struct compat_sigframe {
+	struct compat_ucontext	uc;
+	compat_ulong_t		retcode[2];
+};
+
+struct compat_rt_sigframe {
+	struct compat_siginfo info;
+	struct compat_sigframe sig;
+};
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
+{
+	compat_sigset_t	cset;
+
+	cset.sig[0] = set->sig[0] & 0xffffffffull;
+	cset.sig[1] = set->sig[0] >> 32;
+
+	return copy_to_user(uset, &cset, sizeof(*uset));
+}
+
+static inline int get_sigset_t(sigset_t *set,
+			       const compat_sigset_t __user *uset)
+{
+	compat_sigset_t s32;
+
+	if (copy_from_user(&s32, uset, sizeof(*uset)))
+		return -EFAULT;
+
+	set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
+	return 0;
+}
+
+int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
+{
+	int err;
+
+	if (!access_ok(VERIFY_WRITE, to, sizeof(*to)))
+		return -EFAULT;
+
+	/* If you change siginfo_t structure, please be sure
+	 * this code is fixed accordingly.
+	 * It should never copy any pad contained in the structure
+	 * to avoid security leaks, but must copy the generic
+	 * 3 ints plus the relevant union member.
+	 * This routine must convert siginfo from 64bit to 32bit as well
+	 * at the same time.
+	 */
+	err = __put_user(from->si_signo, &to->si_signo);
+	err |= __put_user(from->si_errno, &to->si_errno);
+	err |= __put_user((short)from->si_code, &to->si_code);
+	if (from->si_code < 0)
+		err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad,
+				      SI_PAD_SIZE);
+	else switch (from->si_code & __SI_MASK) {
+	case __SI_KILL:
+		err |= __put_user(from->si_pid, &to->si_pid);
+		err |= __put_user(from->si_uid, &to->si_uid);
+		break;
+	case __SI_TIMER:
+		 err |= __put_user(from->si_tid, &to->si_tid);
+		 err |= __put_user(from->si_overrun, &to->si_overrun);
+		 err |= __put_user(from->si_int, &to->si_int);
+		break;
+	case __SI_POLL:
+		err |= __put_user(from->si_band, &to->si_band);
+		err |= __put_user(from->si_fd, &to->si_fd);
+		break;
+	case __SI_FAULT:
+		err |= __put_user((compat_uptr_t)(unsigned long)from->si_addr,
+				  &to->si_addr);
+#ifdef BUS_MCEERR_AO
+		/*
+		 * Other callers might not initialize the si_lsb field,
+		 * so check explicitely for the right codes here.
+		 */
+		if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO)
+			err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
+#endif
+		break;
+	case __SI_CHLD:
+		err |= __put_user(from->si_pid, &to->si_pid);
+		err |= __put_user(from->si_uid, &to->si_uid);
+		err |= __put_user(from->si_status, &to->si_status);
+		err |= __put_user(from->si_utime, &to->si_utime);
+		err |= __put_user(from->si_stime, &to->si_stime);
+		break;
+	case __SI_RT: /* This is not generated by the kernel as of now. */
+	case __SI_MESGQ: /* But this is */
+		err |= __put_user(from->si_pid, &to->si_pid);
+		err |= __put_user(from->si_uid, &to->si_uid);
+		err |= __put_user(from->si_int, &to->si_int);
+		break;
+	case __SI_SYS:
+		err |= __put_user((compat_uptr_t)(unsigned long)
+				from->si_call_addr, &to->si_call_addr);
+		err |= __put_user(from->si_syscall, &to->si_syscall);
+		err |= __put_user(from->si_arch, &to->si_arch);
+		break;
+	default: /* this is just in case for now ... */
+		err |= __put_user(from->si_pid, &to->si_pid);
+		err |= __put_user(from->si_uid, &to->si_uid);
+		break;
+	}
+	return err;
+}
+
+int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
+{
+	memset(to, 0, sizeof *to);
+
+	if (copy_from_user(to, from, __ARCH_SI_PREAMBLE_SIZE) ||
+	    copy_from_user(to->_sifields._pad,
+			   from->_sifields._pad, SI_PAD_SIZE))
+		return -EFAULT;
+
+	return 0;
+}
+
+/*
+ * VFP save/restore code.
+ */
+static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
+{
+	struct fpsimd_state *fpsimd = &current->thread.fpsimd_state;
+	compat_ulong_t magic = VFP_MAGIC;
+	compat_ulong_t size = VFP_STORAGE_SIZE;
+	compat_ulong_t fpscr, fpexc;
+	int err = 0;
+
+	/*
+	 * Save the hardware registers to the fpsimd_state structure.
+	 * Note that this also saves V16-31, which aren't visible
+	 * in AArch32.
+	 */
+	fpsimd_preserve_current_state();
+
+	/* Place structure header on the stack */
+	__put_user_error(magic, &frame->magic, err);
+	__put_user_error(size, &frame->size, err);
+
+	/*
+	 * Now copy the FP registers. Since the registers are packed,
+	 * we can copy the prefix we want (V0-V15) as it is.
+	 * FIXME: Won't work if big endian.
+	 */
+	err |= __copy_to_user(&frame->ufp.fpregs, fpsimd->vregs,
+			      sizeof(frame->ufp.fpregs));
+
+	/* Create an AArch32 fpscr from the fpsr and the fpcr. */
+	fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) |
+		(fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
+	__put_user_error(fpscr, &frame->ufp.fpscr, err);
+
+	/*
+	 * The exception register aren't available so we fake up a
+	 * basic FPEXC and zero everything else.
+	 */
+	fpexc = (1 << 30);
+	__put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
+	__put_user_error(0, &frame->ufp_exc.fpinst, err);
+	__put_user_error(0, &frame->ufp_exc.fpinst2, err);
+
+	return err ? -EFAULT : 0;
+}
+
+static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
+{
+	struct fpsimd_state fpsimd;
+	compat_ulong_t magic = VFP_MAGIC;
+	compat_ulong_t size = VFP_STORAGE_SIZE;
+	compat_ulong_t fpscr;
+	int err = 0;
+
+	__get_user_error(magic, &frame->magic, err);
+	__get_user_error(size, &frame->size, err);
+
+	if (err)
+		return -EFAULT;
+	if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
+		return -EINVAL;
+
+	/*
+	 * Copy the FP registers into the start of the fpsimd_state.
+	 * FIXME: Won't work if big endian.
+	 */
+	err |= __copy_from_user(fpsimd.vregs, frame->ufp.fpregs,
+				sizeof(frame->ufp.fpregs));
+
+	/* Extract the fpsr and the fpcr from the fpscr */
+	__get_user_error(fpscr, &frame->ufp.fpscr, err);
+	fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
+	fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
+
+	/*
+	 * We don't need to touch the exception register, so
+	 * reload the hardware state.
+	 */
+	if (!err)
+		fpsimd_update_current_state(&fpsimd);
+
+	return err ? -EFAULT : 0;
+}
+
+static int compat_restore_sigframe(struct pt_regs *regs,
+				   struct compat_sigframe __user *sf)
+{
+	int err;
+	sigset_t set;
+	struct compat_aux_sigframe __user *aux;
+
+	err = get_sigset_t(&set, &sf->uc.uc_sigmask);
+	if (err == 0) {
+		sigdelsetmask(&set, ~_BLOCKABLE);
+		set_current_blocked(&set);
+	}
+
+	__get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
+	__get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
+	__get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
+	__get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
+	__get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
+	__get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
+	__get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
+	__get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
+	__get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
+	__get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
+	__get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
+	__get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
+	__get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
+	__get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
+	__get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
+	__get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
+	__get_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
+
+	/*
+	 * Avoid compat_sys_sigreturn() restarting.
+	 */
+	regs->syscallno = ~0UL;
+
+	err |= !valid_user_regs(&regs->user_regs);
+
+	aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
+	if (err == 0)
+		err |= compat_restore_vfp_context(&aux->vfp);
+
+	return err;
+}
+
+asmlinkage int compat_sys_sigreturn(struct pt_regs *regs)
+{
+	struct compat_sigframe __user *frame;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+	/*
+	 * Since we stacked the signal on a 64-bit boundary,
+	 * then 'sp' should be word aligned here.  If it's
+	 * not, then the user is trying to mess with us.
+	 */
+	if (regs->compat_sp & 7)
+		goto badframe;
+
+	frame = (struct compat_sigframe __user *)regs->compat_sp;
+
+	if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
+		goto badframe;
+
+	if (compat_restore_sigframe(regs, frame))
+		goto badframe;
+
+	return regs->regs[0];
+
+badframe:
+	if (show_unhandled_signals)
+		pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
+				    current->comm, task_pid_nr(current), __func__,
+				    regs->pc, regs->sp);
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs)
+{
+	struct compat_rt_sigframe __user *frame;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+	/*
+	 * Since we stacked the signal on a 64-bit boundary,
+	 * then 'sp' should be word aligned here.  If it's
+	 * not, then the user is trying to mess with us.
+	 */
+	if (regs->compat_sp & 7)
+		goto badframe;
+
+	frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
+
+	if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
+		goto badframe;
+
+	if (compat_restore_sigframe(regs, &frame->sig))
+		goto badframe;
+
+	if (compat_restore_altstack(&frame->sig.uc.uc_stack))
+		goto badframe;
+
+	return regs->regs[0];
+
+badframe:
+	if (show_unhandled_signals)
+		pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
+				    current->comm, task_pid_nr(current), __func__,
+				    regs->pc, regs->sp);
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+static void __user *compat_get_sigframe(struct ksignal *ksig,
+					struct pt_regs *regs,
+					int framesize)
+{
+	compat_ulong_t sp = sigsp(regs->compat_sp, ksig);
+	void __user *frame;
+
+	/*
+	 * ATPCS B01 mandates 8-byte alignment
+	 */
+	frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));
+
+	/*
+	 * Check that we can actually write to the signal frame.
+	 */
+	if (!access_ok(VERIFY_WRITE, frame, framesize))
+		frame = NULL;
+
+	return frame;
+}
+
+static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
+				compat_ulong_t __user *rc, void __user *frame,
+				int usig)
+{
+	compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
+	compat_ulong_t retcode;
+	compat_ulong_t spsr = regs->pstate & ~(PSR_f | COMPAT_PSR_E_BIT);
+	int thumb;
+
+	/* Check if the handler is written for ARM or Thumb */
+	thumb = handler & 1;
+
+	if (thumb)
+		spsr |= COMPAT_PSR_T_BIT;
+	else
+		spsr &= ~COMPAT_PSR_T_BIT;
+
+	/* The IT state must be cleared for both ARM and Thumb-2 */
+	spsr &= ~COMPAT_PSR_IT_MASK;
+
+	/* Restore the original endianness */
+	spsr |= COMPAT_PSR_ENDSTATE;
+
+	if (ka->sa.sa_flags & SA_RESTORER) {
+		retcode = ptr_to_compat(ka->sa.sa_restorer);
+	} else {
+		/* Set up sigreturn pointer */
+		unsigned int idx = thumb << 1;
+
+		if (ka->sa.sa_flags & SA_SIGINFO)
+			idx += 3;
+
+		retcode = AARCH32_VECTORS_BASE +
+			  AARCH32_KERN_SIGRET_CODE_OFFSET +
+			  (idx << 2) + thumb;
+	}
+
+	regs->regs[0]	= usig;
+	regs->compat_sp	= ptr_to_compat(frame);
+	regs->compat_lr	= retcode;
+	regs->pc	= handler;
+	regs->pstate	= spsr;
+}
+
+static int compat_setup_sigframe(struct compat_sigframe __user *sf,
+				 struct pt_regs *regs, sigset_t *set)
+{
+	struct compat_aux_sigframe __user *aux;
+	int err = 0;
+
+	__put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
+	__put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
+	__put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
+	__put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
+	__put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
+	__put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
+	__put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
+	__put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
+	__put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
+	__put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
+	__put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
+	__put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
+	__put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
+	__put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
+	__put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
+	__put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
+	__put_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
+
+	__put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
+	/* set the compat FSR WnR */
+	__put_user_error(!!(current->thread.fault_code & ESR_EL1_WRITE) <<
+			 FSR_WRITE_SHIFT, &sf->uc.uc_mcontext.error_code, err);
+	__put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
+	__put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
+
+	err |= put_sigset_t(&sf->uc.uc_sigmask, set);
+
+	aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
+
+	if (err == 0)
+		err |= compat_preserve_vfp_context(&aux->vfp);
+	__put_user_error(0, &aux->end_magic, err);
+
+	return err;
+}
+
+/*
+ * 32-bit signal handling routines called from signal.c
+ */
+int compat_setup_rt_frame(int usig, struct ksignal *ksig,
+			  sigset_t *set, struct pt_regs *regs)
+{
+	struct compat_rt_sigframe __user *frame;
+	int err = 0;
+
+	frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
+
+	if (!frame)
+		return 1;
+
+	err |= copy_siginfo_to_user32(&frame->info, &ksig->info);
+
+	__put_user_error(0, &frame->sig.uc.uc_flags, err);
+	__put_user_error(0, &frame->sig.uc.uc_link, err);
+
+	err |= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->compat_sp);
+
+	err |= compat_setup_sigframe(&frame->sig, regs, set);
+
+	if (err == 0) {
+		compat_setup_return(regs, &ksig->ka, frame->sig.retcode, frame, usig);
+		regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
+		regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
+	}
+
+	return err;
+}
+
+int compat_setup_frame(int usig, struct ksignal *ksig, sigset_t *set,
+		       struct pt_regs *regs)
+{
+	struct compat_sigframe __user *frame;
+	int err = 0;
+
+	frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
+
+	if (!frame)
+		return 1;
+
+	__put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
+
+	err |= compat_setup_sigframe(frame, regs, set);
+	if (err == 0)
+		compat_setup_return(regs, &ksig->ka, frame->retcode, frame, usig);
+
+	return err;
+}
+
+void compat_setup_restart_syscall(struct pt_regs *regs)
+{
+       regs->regs[7] = __NR_compat_restart_syscall;
+}

arch/arm64/kernel/sleep.S

@@ -0,0 +1,181 @@
+#include <linux/errno.h>
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/assembler.h>
+
+	.text
+/*
+ * Implementation of MPIDR_EL1 hash algorithm through shifting
+ * and OR'ing.
+ *
+ * @dst: register containing hash result
+ * @rs0: register containing affinity level 0 bit shift
+ * @rs1: register containing affinity level 1 bit shift
+ * @rs2: register containing affinity level 2 bit shift
+ * @rs3: register containing affinity level 3 bit shift
+ * @mpidr: register containing MPIDR_EL1 value
+ * @mask: register containing MPIDR mask
+ *
+ * Pseudo C-code:
+ *
+ *u32 dst;
+ *
+ *compute_mpidr_hash(u32 rs0, u32 rs1, u32 rs2, u32 rs3, u64 mpidr, u64 mask) {
+ *	u32 aff0, aff1, aff2, aff3;
+ *	u64 mpidr_masked = mpidr & mask;
+ *	aff0 = mpidr_masked & 0xff;
+ *	aff1 = mpidr_masked & 0xff00;
+ *	aff2 = mpidr_masked & 0xff0000;
+ *	aff2 = mpidr_masked & 0xff00000000;
+ *	dst = (aff0 >> rs0 | aff1 >> rs1 | aff2 >> rs2 | aff3 >> rs3);
+ *}
+ * Input registers: rs0, rs1, rs2, rs3, mpidr, mask
+ * Output register: dst
+ * Note: input and output registers must be disjoint register sets
+         (eg: a macro instance with mpidr = x1 and dst = x1 is invalid)
+ */
+	.macro compute_mpidr_hash dst, rs0, rs1, rs2, rs3, mpidr, mask
+	and	\mpidr, \mpidr, \mask		// mask out MPIDR bits
+	and	\dst, \mpidr, #0xff		// mask=aff0
+	lsr	\dst ,\dst, \rs0		// dst=aff0>>rs0
+	and	\mask, \mpidr, #0xff00		// mask = aff1
+	lsr	\mask ,\mask, \rs1
+	orr	\dst, \dst, \mask		// dst|=(aff1>>rs1)
+	and	\mask, \mpidr, #0xff0000	// mask = aff2
+	lsr	\mask ,\mask, \rs2
+	orr	\dst, \dst, \mask		// dst|=(aff2>>rs2)
+	and	\mask, \mpidr, #0xff00000000	// mask = aff3
+	lsr	\mask ,\mask, \rs3
+	orr	\dst, \dst, \mask		// dst|=(aff3>>rs3)
+	.endm
+/*
+ * Save CPU state for a suspend and execute the suspend finisher.
+ * On success it will return 0 through cpu_resume - ie through a CPU
+ * soft/hard reboot from the reset vector.
+ * On failure it returns the suspend finisher return value or force
+ * -EOPNOTSUPP if the finisher erroneously returns 0 (the suspend finisher
+ * is not allowed to return, if it does this must be considered failure).
+ * It saves callee registers, and allocates space on the kernel stack
+ * to save the CPU specific registers + some other data for resume.
+ *
+ *  x0 = suspend finisher argument
+ *  x1 = suspend finisher function pointer
+ */
+ENTRY(__cpu_suspend_enter)
+	stp	x29, lr, [sp, #-96]!
+	stp	x19, x20, [sp,#16]
+	stp	x21, x22, [sp,#32]
+	stp	x23, x24, [sp,#48]
+	stp	x25, x26, [sp,#64]
+	stp	x27, x28, [sp,#80]
+	/*
+	 * Stash suspend finisher and its argument in x20 and x19
+	 */
+	mov	x19, x0
+	mov	x20, x1
+	mov	x2, sp
+	sub	sp, sp, #CPU_SUSPEND_SZ	// allocate cpu_suspend_ctx
+	mov	x0, sp
+	/*
+	 * x0 now points to struct cpu_suspend_ctx allocated on the stack
+	 */
+	str	x2, [x0, #CPU_CTX_SP]
+	ldr	x1, =sleep_save_sp
+	ldr	x1, [x1, #SLEEP_SAVE_SP_VIRT]
+#ifdef CONFIG_SMP
+	mrs	x7, mpidr_el1
+	ldr	x9, =mpidr_hash
+	ldr	x10, [x9, #MPIDR_HASH_MASK]
+	/*
+	 * Following code relies on the struct mpidr_hash
+	 * members size.
+	 */
+	ldp	w3, w4, [x9, #MPIDR_HASH_SHIFTS]
+	ldp	w5, w6, [x9, #(MPIDR_HASH_SHIFTS + 8)]
+	compute_mpidr_hash x8, x3, x4, x5, x6, x7, x10
+	add	x1, x1, x8, lsl #3
+#endif
+	bl	__cpu_suspend_save
+	/*
+	 * Grab suspend finisher in x20 and its argument in x19
+	 */
+	mov	x0, x19
+	mov	x1, x20
+	/*
+	 * We are ready for power down, fire off the suspend finisher
+	 * in x1, with argument in x0
+	 */
+	blr	x1
+        /*
+	 * Never gets here, unless suspend finisher fails.
+	 * Successful cpu_suspend should return from cpu_resume, returning
+	 * through this code path is considered an error
+	 * If the return value is set to 0 force x0 = -EOPNOTSUPP
+	 * to make sure a proper error condition is propagated
+	 */
+	cmp	x0, #0
+	mov	x3, #-EOPNOTSUPP
+	csel	x0, x3, x0, eq
+	add	sp, sp, #CPU_SUSPEND_SZ	// rewind stack pointer
+	ldp	x19, x20, [sp, #16]
+	ldp	x21, x22, [sp, #32]
+	ldp	x23, x24, [sp, #48]
+	ldp	x25, x26, [sp, #64]
+	ldp	x27, x28, [sp, #80]
+	ldp	x29, lr, [sp], #96
+	ret
+ENDPROC(__cpu_suspend_enter)
+	.ltorg
+
+/*
+ * x0 must contain the sctlr value retrieved from restored context
+ */
+ENTRY(cpu_resume_mmu)
+	ldr	x3, =cpu_resume_after_mmu
+	msr	sctlr_el1, x0		// restore sctlr_el1
+	isb
+	br	x3			// global jump to virtual address
+ENDPROC(cpu_resume_mmu)
+cpu_resume_after_mmu:
+	mov	x0, #0			// return zero on success
+	ldp	x19, x20, [sp, #16]
+	ldp	x21, x22, [sp, #32]
+	ldp	x23, x24, [sp, #48]
+	ldp	x25, x26, [sp, #64]
+	ldp	x27, x28, [sp, #80]
+	ldp	x29, lr, [sp], #96
+	ret
+ENDPROC(cpu_resume_after_mmu)
+
+ENTRY(cpu_resume)
+	bl	el2_setup		// if in EL2 drop to EL1 cleanly
+#ifdef CONFIG_SMP
+	mrs	x1, mpidr_el1
+	adrp	x8, mpidr_hash
+	add x8, x8, #:lo12:mpidr_hash // x8 = struct mpidr_hash phys address
+        /* retrieve mpidr_hash members to compute the hash */
+	ldr	x2, [x8, #MPIDR_HASH_MASK]
+	ldp	w3, w4, [x8, #MPIDR_HASH_SHIFTS]
+	ldp	w5, w6, [x8, #(MPIDR_HASH_SHIFTS + 8)]
+	compute_mpidr_hash x7, x3, x4, x5, x6, x1, x2
+        /* x7 contains hash index, let's use it to grab context pointer */
+#else
+	mov	x7, xzr
+#endif
+	adrp	x0, sleep_save_sp
+	add	x0, x0, #:lo12:sleep_save_sp
+	ldr	x0, [x0, #SLEEP_SAVE_SP_PHYS]
+	ldr	x0, [x0, x7, lsl #3]
+	/* load sp from context */
+	ldr	x2, [x0, #CPU_CTX_SP]
+	adrp	x1, sleep_idmap_phys
+	/* load physical address of identity map page table in x1 */
+	ldr	x1, [x1, #:lo12:sleep_idmap_phys]
+	mov	sp, x2
+	/*
+	 * cpu_do_resume expects x0 to contain context physical address
+	 * pointer and x1 to contain physical address of 1:1 page tables
+	 */
+	bl	cpu_do_resume		// PC relative jump, MMU off
+	b	cpu_resume_mmu		// Resume MMU, never returns
+ENDPROC(cpu_resume)

arch/arm64/kernel/smp.c

@@ -0,0 +1,729 @@
+/*
+ * SMP initialisation and IPI support
+ * Based on arch/arm/kernel/smp.c
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/cache.h>
+#include <linux/profile.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/err.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <linux/seq_file.h>
+#include <linux/irq.h>
+#include <linux/percpu.h>
+#include <linux/clockchips.h>
+#include <linux/completion.h>
+#include <linux/of.h>
+#include <linux/irq_work.h>
+#include <linux/exynos-ss.h>
+
+#include <asm/alternative.h>
+#include <asm/atomic.h>
+#include <asm/cacheflush.h>
+#include <asm/cpu.h>
+#include <asm/cputype.h>
+#include <asm/cpu_ops.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/processor.h>
+#include <asm/smp_plat.h>
+#include <asm/sections.h>
+#include <asm/tlbflush.h>
+#include <asm/ptrace.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/ipi.h>
+
+extern void machine_crash_nonpanic_core(void *unused);
+
+/*
+ * as from 2.5, kernels no longer have an init_tasks structure
+ * so we need some other way of telling a new secondary core
+ * where to place its SVC stack
+ */
+struct secondary_data secondary_data;
+
+enum ipi_msg_type {
+	IPI_RESCHEDULE,
+	IPI_CALL_FUNC,
+	IPI_CALL_FUNC_SINGLE,
+	IPI_CPU_STOP,
+	IPI_TIMER,
+	IPI_IRQ_WORK,
+	IPI_WAKEUP,
+};
+
+/*
+ * Boot a secondary CPU, and assign it the specified idle task.
+ * This also gives us the initial stack to use for this CPU.
+ */
+static int boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	if (cpu_ops[cpu]->cpu_boot)
+		return cpu_ops[cpu]->cpu_boot(cpu);
+
+	return -EOPNOTSUPP;
+}
+
+static DECLARE_COMPLETION(cpu_running);
+
+int __cpu_up(unsigned int cpu, struct task_struct *idle)
+{
+	int ret;
+
+	/*
+	 * We need to tell the secondary core where to find its stack and the
+	 * page tables.
+	 */
+	secondary_data.stack = task_stack_page(idle) + THREAD_START_SP;
+	__flush_dcache_area(&secondary_data, sizeof(secondary_data));
+
+	/*
+	 * Now bring the CPU into our world.
+	 */
+	ret = boot_secondary(cpu, idle);
+	if (ret == 0) {
+		/*
+		 * CPU was successfully started, wait for it to come online or
+		 * time out.
+		 */
+		wait_for_completion_timeout(&cpu_running,
+					    msecs_to_jiffies(1000));
+
+		if (!cpu_online(cpu)) {
+			pr_crit("CPU%u: failed to come online\n", cpu);
+			ret = -EIO;
+		}
+	} else {
+		pr_err("CPU%u: failed to boot: %d\n", cpu, ret);
+	}
+
+	secondary_data.stack = NULL;
+
+	return ret;
+}
+
+static void smp_store_cpu_info(unsigned int cpuid)
+{
+	store_cpu_topology(cpuid);
+}
+
+/*
+ * This is the secondary CPU boot entry.  We're using this CPUs
+ * idle thread stack, but a set of temporary page tables.
+ */
+asmlinkage void secondary_start_kernel(void)
+{
+	struct mm_struct *mm = &init_mm;
+	unsigned int cpu = smp_processor_id();
+
+	/*
+	 * All kernel threads share the same mm context; grab a
+	 * reference and switch to it.
+	 */
+	atomic_inc(&mm->mm_count);
+	current->active_mm = mm;
+	cpumask_set_cpu(cpu, mm_cpumask(mm));
+
+	set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
+	printk("CPU%u: Booted secondary processor\n", cpu);
+
+	/*
+	 * TTBR0 is only used for the identity mapping at this stage. Make it
+	 * point to zero page to avoid speculatively fetching new entries.
+	 */
+	cpu_set_reserved_ttbr0();
+	flush_tlb_all();
+
+	preempt_disable();
+	trace_hardirqs_off();
+
+	if (cpu_ops[cpu]->cpu_postboot)
+		cpu_ops[cpu]->cpu_postboot();
+
+	/*
+	 * Log the CPU info before it is marked online and might get read.
+	 */
+	cpuinfo_store_cpu();
+
+	/*
+	 * Enable GIC and timers.
+	 */
+	notify_cpu_starting(cpu);
+
+	smp_store_cpu_info(cpu);
+
+	/*
+	 * OK, now it's safe to let the boot CPU continue.  Wait for
+	 * the CPU migration code to notice that the CPU is online
+	 * before we continue.
+	 */
+	set_cpu_online(cpu, true);
+	complete(&cpu_running);
+
+	local_dbg_enable();
+	local_irq_enable();
+	local_async_enable();
+
+	/*
+	 * OK, it's off to the idle thread for us
+	 */
+	cpu_startup_entry(CPUHP_ONLINE);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static int op_cpu_disable(unsigned int cpu)
+{
+	/*
+	 * If we don't have a cpu_die method, abort before we reach the point
+	 * of no return. CPU0 may not have an cpu_ops, so test for it.
+	 */
+	if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_die)
+		return -EOPNOTSUPP;
+
+	/*
+	 * We may need to abort a hot unplug for some other mechanism-specific
+	 * reason.
+	 */
+	if (cpu_ops[cpu]->cpu_disable)
+		return cpu_ops[cpu]->cpu_disable(cpu);
+
+	return 0;
+}
+
+/*
+ * __cpu_disable runs on the processor to be shutdown.
+ */
+int __cpu_disable(void)
+{
+	unsigned int cpu = smp_processor_id();
+	int ret;
+
+	ret = op_cpu_disable(cpu);
+	if (ret)
+		return ret;
+
+	/*
+	 * Take this CPU offline.  Once we clear this, we can't return,
+	 * and we must not schedule until we're ready to give up the cpu.
+	 */
+	set_cpu_online(cpu, false);
+
+	/*
+	 * OK - migrate IRQs away from this CPU
+	 */
+	migrate_irqs();
+
+	/*
+	 * Remove this CPU from the vm mask set of all processes.
+	 */
+	clear_tasks_mm_cpumask(cpu);
+
+	return 0;
+}
+
+static int op_cpu_kill(unsigned int cpu)
+{
+	/*
+	 * If we have no means of synchronising with the dying CPU, then assume
+	 * that it is really dead. We can only wait for an arbitrary length of
+	 * time and hope that it's dead, so let's skip the wait and just hope.
+	 */
+	if (!cpu_ops[cpu]->cpu_kill)
+		return 1;
+
+	return cpu_ops[cpu]->cpu_kill(cpu);
+}
+
+static DECLARE_COMPLETION(cpu_died);
+
+/*
+ * called on the thread which is asking for a CPU to be shutdown -
+ * waits until shutdown has completed, or it is timed out.
+ */
+void __cpu_die(unsigned int cpu)
+{
+	if (!wait_for_completion_timeout(&cpu_died, msecs_to_jiffies(5000))) {
+		pr_crit("CPU%u: cpu didn't die\n", cpu);
+		return;
+	}
+	pr_notice("CPU%u: shutdown\n", cpu);
+
+	/*
+	 * Now that the dying CPU is beyond the point of no return w.r.t.
+	 * in-kernel synchronisation, try to get the firwmare to help us to
+	 * verify that it has really left the kernel before we consider
+	 * clobbering anything it might still be using.
+	 */
+	if (!op_cpu_kill(cpu))
+		pr_warn("CPU%d may not have shut down cleanly\n", cpu);
+}
+
+/*
+ * Called from the idle thread for the CPU which has been shutdown.
+ *
+ * Note that we disable IRQs here, but do not re-enable them
+ * before returning to the caller. This is also the behaviour
+ * of the other hotplug-cpu capable cores, so presumably coming
+ * out of idle fixes this.
+ */
+void cpu_die(void)
+{
+	unsigned int cpu = smp_processor_id();
+
+	idle_task_exit();
+
+	local_irq_disable();
+
+	/* Tell __cpu_die() that this CPU is now safe to dispose of */
+	complete(&cpu_died);
+
+	/*
+	 * Actually shutdown the CPU. This must never fail. The specific hotplug
+	 * mechanism must perform all required cache maintenance to ensure that
+	 * no dirty lines are lost in the process of shutting down the CPU.
+	 */
+	cpu_ops[cpu]->cpu_die(cpu);
+
+	BUG();
+}
+#endif
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+	pr_info("SMP: Total of %d processors activated.\n", num_online_cpus());
+	apply_alternatives();
+}
+
+void __init smp_prepare_boot_cpu(void)
+{
+	set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
+}
+
+/*
+ * Enumerate the possible CPU set from the device tree and build the
+ * cpu logical map array containing MPIDR values related to logical
+ * cpus. Assumes that cpu_logical_map(0) has already been initialized.
+ */
+void __init smp_init_cpus(void)
+{
+	struct device_node *dn = NULL;
+	unsigned int i, cpu = 1;
+	bool bootcpu_valid = false;
+
+	while ((dn = of_find_node_by_type(dn, "cpu"))) {
+		const u32 *cell;
+		u64 hwid;
+
+		/*
+		 * A cpu node with missing "reg" property is
+		 * considered invalid to build a cpu_logical_map
+		 * entry.
+		 */
+		cell = of_get_property(dn, "reg", NULL);
+		if (!cell) {
+			pr_err("%s: missing reg property\n", dn->full_name);
+			goto next;
+		}
+		hwid = of_read_number(cell, of_n_addr_cells(dn));
+
+		/*
+		 * Non affinity bits must be set to 0 in the DT
+		 */
+		if (hwid & ~MPIDR_HWID_BITMASK) {
+			pr_err("%s: invalid reg property\n", dn->full_name);
+			goto next;
+		}
+
+		/*
+		 * Duplicate MPIDRs are a recipe for disaster. Scan
+		 * all initialized entries and check for
+		 * duplicates. If any is found just ignore the cpu.
+		 * cpu_logical_map was initialized to INVALID_HWID to
+		 * avoid matching valid MPIDR values.
+		 */
+		for (i = 1; (i < cpu) && (i < NR_CPUS); i++) {
+			if (cpu_logical_map(i) == hwid) {
+				pr_err("%s: duplicate cpu reg properties in the DT\n",
+					dn->full_name);
+				goto next;
+			}
+		}
+
+		/*
+		 * The numbering scheme requires that the boot CPU
+		 * must be assigned logical id 0. Record it so that
+		 * the logical map built from DT is validated and can
+		 * be used.
+		 */
+		if (hwid == cpu_logical_map(0)) {
+			if (bootcpu_valid) {
+				pr_err("%s: duplicate boot cpu reg property in DT\n",
+					dn->full_name);
+				goto next;
+			}
+
+			bootcpu_valid = true;
+
+			/*
+			 * cpu_logical_map has already been
+			 * initialized and the boot cpu doesn't need
+			 * the enable-method so continue without
+			 * incrementing cpu.
+			 */
+			continue;
+		}
+
+		if (cpu >= NR_CPUS)
+			goto next;
+
+		if (cpu_read_ops(dn, cpu) != 0)
+			goto next;
+
+		if (cpu_ops[cpu]->cpu_init(dn, cpu))
+			goto next;
+
+		pr_debug("cpu logical map 0x%llx\n", hwid);
+		cpu_logical_map(cpu) = hwid;
+next:
+		cpu++;
+	}
+
+	/* sanity check */
+	if (cpu > NR_CPUS)
+		pr_warning("no. of cores (%d) greater than configured maximum of %d - clipping\n",
+			   cpu, NR_CPUS);
+
+	if (!bootcpu_valid) {
+		pr_err("DT missing boot CPU MPIDR, not enabling secondaries\n");
+		return;
+	}
+
+	/*
+	 * All the cpus that made it to the cpu_logical_map have been
+	 * validated so set them as possible cpus.
+	 */
+	for (i = 0; i < NR_CPUS; i++)
+		if (cpu_logical_map(i) != INVALID_HWID)
+			set_cpu_possible(i, true);
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+	int err;
+	unsigned int cpu, ncores = num_possible_cpus();
+
+	init_cpu_topology();
+
+	smp_store_cpu_info(smp_processor_id());
+
+	/*
+	 * are we trying to boot more cores than exist?
+	 */
+	if (max_cpus > ncores)
+		max_cpus = ncores;
+
+	/* Don't bother if we're effectively UP */
+	if (max_cpus <= 1)
+		return;
+
+	/*
+	 * Initialise the present map (which describes the set of CPUs
+	 * actually populated at the present time) and release the
+	 * secondaries from the bootloader.
+	 *
+	 * Make sure we online at most (max_cpus - 1) additional CPUs.
+	 */
+	max_cpus--;
+	for_each_possible_cpu(cpu) {
+		if (max_cpus == 0)
+			break;
+
+		if (cpu == smp_processor_id())
+			continue;
+
+		if (!cpu_ops[cpu])
+			continue;
+
+		err = cpu_ops[cpu]->cpu_prepare(cpu);
+		if (err)
+			continue;
+
+		set_cpu_present(cpu, true);
+		max_cpus--;
+	}
+}
+
+void (*__smp_cross_call)(const struct cpumask *, unsigned int);
+
+void __init set_smp_cross_call(void (*fn)(const struct cpumask *, unsigned int))
+{
+	__smp_cross_call = fn;
+}
+
+static const char *ipi_types[NR_IPI] __tracepoint_string = {
+#define S(x,s)	[x] = s
+	S(IPI_RESCHEDULE, "Rescheduling interrupts"),
+	S(IPI_CALL_FUNC, "Function call interrupts"),
+	S(IPI_CALL_FUNC_SINGLE, "Single function call interrupts"),
+	S(IPI_CPU_STOP, "CPU stop interrupts"),
+	S(IPI_TIMER, "Timer broadcast interrupts"),
+	S(IPI_IRQ_WORK, "IRQ work interrupts"),
+	S(IPI_WAKEUP, "CPU Wakeup by interrupts"),
+};
+
+static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
+{
+	trace_ipi_raise(target, ipi_types[ipinr]);
+	__smp_cross_call(target, ipinr);
+}
+
+void show_ipi_list(struct seq_file *p, int prec)
+{
+	unsigned int cpu, i;
+
+	for (i = 0; i < NR_IPI; i++) {
+		seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
+			   prec >= 4 ? " " : "");
+		for_each_online_cpu(cpu)
+			seq_printf(p, "%10u ",
+				   __get_irq_stat(cpu, ipi_irqs[i]));
+		seq_printf(p, "      %s\n", ipi_types[i]);
+	}
+}
+
+u64 smp_irq_stat_cpu(unsigned int cpu)
+{
+	u64 sum = 0;
+	int i;
+
+	for (i = 0; i < NR_IPI; i++)
+		sum += __get_irq_stat(cpu, ipi_irqs[i]);
+
+	return sum;
+}
+
+void arch_send_call_function_ipi_mask(const struct cpumask *mask)
+{
+	smp_cross_call(mask, IPI_CALL_FUNC);
+}
+
+void arch_send_call_function_single_ipi(int cpu)
+{
+	smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
+}
+
+#ifdef CONFIG_IRQ_WORK
+void arch_irq_work_raise(void)
+{
+	if (__smp_cross_call)
+		smp_cross_call(cpumask_of(smp_processor_id()), IPI_IRQ_WORK);
+}
+#endif
+
+static DEFINE_RAW_SPINLOCK(stop_lock);
+
+/*
+ * ipi_cpu_stop - handle IPI from smp_send_stop()
+ */
+static void ipi_cpu_stop(unsigned int cpu, struct pt_regs *regs)
+{
+	if (system_state == SYSTEM_BOOTING ||
+	    system_state == SYSTEM_RUNNING) {
+		raw_spin_lock(&stop_lock);
+		pr_crit("CPU%u: stopping\n", cpu);
+		dump_stack();
+		raw_spin_unlock(&stop_lock);
+	}
+
+	set_cpu_online(cpu, false);
+
+	local_irq_disable();
+
+	machine_crash_nonpanic_core(NULL);
+	exynos_ss_save_context(regs);
+
+	while (1)
+		wfi();
+}
+
+/*
+ * Main handler for inter-processor interrupts
+ */
+void handle_IPI(int ipinr, struct pt_regs *regs)
+{
+	unsigned int cpu = smp_processor_id();
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	if ((unsigned)ipinr < NR_IPI) {
+		trace_ipi_entry(ipi_types[ipinr]);
+		__inc_irq_stat(cpu, ipi_irqs[ipinr]);
+	}
+
+	exynos_ss_irq(ipinr, handle_IPI, irqs_disabled(), ESS_FLAG_IN);
+
+	switch (ipinr) {
+	case IPI_RESCHEDULE:
+		scheduler_ipi();
+		break;
+
+	case IPI_CALL_FUNC:
+		irq_enter();
+		generic_smp_call_function_interrupt();
+		irq_exit();
+		break;
+
+	case IPI_CALL_FUNC_SINGLE:
+		irq_enter();
+		generic_smp_call_function_single_interrupt();
+		irq_exit();
+		break;
+
+	case IPI_CPU_STOP:
+		irq_enter();
+		ipi_cpu_stop(cpu, regs);
+		irq_exit();
+		break;
+
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+	case IPI_TIMER:
+		irq_enter();
+		tick_receive_broadcast();
+		irq_exit();
+		break;
+#endif
+
+#ifdef CONFIG_IRQ_WORK
+	case IPI_IRQ_WORK:
+		irq_enter();
+		irq_work_run();
+		irq_exit();
+		break;
+#endif
+	case IPI_WAKEUP:
+		pr_debug("%s: IPI_WAKEUP\n", __func__);
+		break;
+
+	default:
+		pr_crit("CPU%u: Unknown IPI message 0x%x\n", cpu, ipinr);
+		break;
+	}
+
+	if ((unsigned)ipinr < NR_IPI)
+		trace_ipi_exit(ipi_types[ipinr]);
+
+	exynos_ss_irq(ipinr, handle_IPI, irqs_disabled(), ESS_FLAG_OUT);
+	set_irq_regs(old_regs);
+}
+
+void smp_send_reschedule(int cpu)
+{
+	smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
+}
+
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+void tick_broadcast(const struct cpumask *mask)
+{
+	smp_cross_call(mask, IPI_TIMER);
+}
+#endif
+
+void smp_send_stop(void)
+{
+	unsigned long timeout;
+
+	if (num_online_cpus() > 1) {
+		cpumask_t mask;
+
+		cpumask_copy(&mask, cpu_online_mask);
+		cpu_clear(smp_processor_id(), mask);
+
+		smp_cross_call(&mask, IPI_CPU_STOP);
+	}
+
+	/* Wait up to 5 seconds for other CPUs to stop */
+	timeout = USEC_PER_SEC * 5;
+	while (num_online_cpus() > 1 && timeout--)
+		udelay(1);
+
+	if (num_online_cpus() > 1)
+		pr_warning("SMP: failed to stop secondary CPUs\n");
+	else
+		pr_info("SMP: completed to stop secondary CPUS\n");
+}
+
+/*
+ * not supported here
+ */
+int setup_profiling_timer(unsigned int multiplier)
+{
+	return -EINVAL;
+}
+
+static void flush_all_cpu_cache(void *info)
+{
+	flush_cache_louis();
+}
+
+#ifdef CONFIG_SCHED_HMP
+
+#include <asm/cputype.h>
+
+extern struct cpumask hmp_slow_cpu_mask;
+extern struct cpumask hmp_fast_cpu_mask;
+
+static void flush_all_cluster_cache(void *info)
+{
+	flush_cache_all();
+}
+
+void flush_all_cpu_caches(void)
+{
+        unsigned int cpu, cluster, target_cpu;
+
+	preempt_disable();
+	cpu = smp_processor_id();
+	cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
+
+	if (!cluster)
+		target_cpu = first_cpu(hmp_slow_cpu_mask);
+	else
+		target_cpu = first_cpu(hmp_fast_cpu_mask);
+
+	smp_call_function(flush_all_cpu_cache, NULL, 1);
+	smp_call_function_single(target_cpu, flush_all_cluster_cache, NULL, 1);
+	flush_cache_all();
+
+	preempt_enable();
+}
+#else
+void flush_all_cpu_caches(void)
+{
+	preempt_disable();
+	smp_call_function(flush_all_cpu_cache, NULL, 1);
+	flush_cache_all();
+	preempt_enable();
+}
+#endif

arch/arm64/kernel/smp_spin_table.c

@@ -0,0 +1,126 @@
+/*
+ * Spin Table SMP initialisation
+ *
+ * Copyright (C) 2013 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/smp.h>
+#include <linux/types.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cpu_ops.h>
+#include <asm/cputype.h>
+#include <asm/smp_plat.h>
+
+extern void secondary_holding_pen(void);
+volatile unsigned long secondary_holding_pen_release = INVALID_HWID;
+
+static phys_addr_t cpu_release_addr[NR_CPUS];
+
+/*
+ * Write secondary_holding_pen_release in a way that is guaranteed to be
+ * visible to all observers, irrespective of whether they're taking part
+ * in coherency or not.  This is necessary for the hotplug code to work
+ * reliably.
+ */
+static void write_pen_release(u64 val)
+{
+	void *start = (void *)&secondary_holding_pen_release;
+	unsigned long size = sizeof(secondary_holding_pen_release);
+
+	secondary_holding_pen_release = val;
+	__flush_dcache_area(start, size);
+}
+
+
+static int smp_spin_table_cpu_init(struct device_node *dn, unsigned int cpu)
+{
+	/*
+	 * Determine the address from which the CPU is polling.
+	 */
+	if (of_property_read_u64(dn, "cpu-release-addr",
+				 &cpu_release_addr[cpu])) {
+		pr_err("CPU %d: missing or invalid cpu-release-addr property\n",
+		       cpu);
+
+		return -1;
+	}
+
+	return 0;
+}
+
+static int smp_spin_table_cpu_prepare(unsigned int cpu)
+{
+	__le64 __iomem *release_addr;
+
+	if (!cpu_release_addr[cpu])
+		return -ENODEV;
+
+	/*
+	 * The cpu-release-addr may or may not be inside the linear mapping.
+	 * As ioremap_cache will either give us a new mapping or reuse the
+	 * existing linear mapping, we can use it to cover both cases. In
+	 * either case the memory will be MT_NORMAL.
+	 */
+	release_addr = ioremap_cache(cpu_release_addr[cpu],
+				     sizeof(*release_addr));
+	if (!release_addr)
+		return -ENOMEM;
+
+	/*
+	 * We write the release address as LE regardless of the native
+	 * endianess of the kernel. Therefore, any boot-loaders that
+	 * read this address need to convert this address to the
+	 * boot-loader's endianess before jumping. This is mandated by
+	 * the boot protocol.
+	 */
+	writeq_relaxed(__pa(secondary_holding_pen), release_addr);
+	__flush_dcache_area((__force void *)release_addr,
+			    sizeof(*release_addr));
+
+	/*
+	 * Send an event to wake up the secondary CPU.
+	 */
+	sev();
+
+	iounmap(release_addr);
+
+	return 0;
+}
+
+static int smp_spin_table_cpu_boot(unsigned int cpu)
+{
+	/*
+	 * Update the pen release flag.
+	 */
+	write_pen_release(cpu_logical_map(cpu));
+
+	/*
+	 * Send an event, causing the secondaries to read pen_release.
+	 */
+	sev();
+
+	return 0;
+}
+
+const struct cpu_operations smp_spin_table_ops = {
+	.name		= "spin-table",
+	.cpu_init	= smp_spin_table_cpu_init,
+	.cpu_prepare	= smp_spin_table_cpu_prepare,
+	.cpu_boot	= smp_spin_table_cpu_boot,
+};

arch/arm64/kernel/stacktrace.c

@@ -0,0 +1,130 @@
+/*
+ * Stack tracing support
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/stacktrace.h>
+
+#include <asm/stacktrace.h>
+
+/*
+ * AArch64 PCS assigns the frame pointer to x29.
+ *
+ * A simple function prologue looks like this:
+ * 	sub	sp, sp, #0x10
+ *   	stp	x29, x30, [sp]
+ *	mov	x29, sp
+ *
+ * A simple function epilogue looks like this:
+ *	mov	sp, x29
+ *	ldp	x29, x30, [sp]
+ *	add	sp, sp, #0x10
+ */
+int notrace unwind_frame(struct stackframe *frame)
+{
+	unsigned long high, low;
+	unsigned long fp = frame->fp;
+
+	low  = frame->sp;
+	high = ALIGN(low, THREAD_SIZE);
+
+	if (fp < low || fp > high - 0x18 || fp & 0xf)
+		return -EINVAL;
+
+	frame->sp = fp + 0x10;
+	frame->fp = *(unsigned long *)(fp);
+	/*
+	 * -4 here because we care about the PC at time of bl,
+	 * not where the return will go.
+	 */
+	frame->pc = *(unsigned long *)(fp + 8) - 4;
+
+	return 0;
+}
+
+void notrace walk_stackframe(struct stackframe *frame,
+		     int (*fn)(struct stackframe *, void *), void *data)
+{
+	while (1) {
+		int ret;
+
+		if (fn(frame, data))
+			break;
+		ret = unwind_frame(frame);
+		if (ret < 0)
+			break;
+	}
+}
+EXPORT_SYMBOL(walk_stackframe);
+
+#ifdef CONFIG_STACKTRACE
+struct stack_trace_data {
+	struct stack_trace *trace;
+	unsigned int no_sched_functions;
+	unsigned int skip;
+};
+
+static int save_trace(struct stackframe *frame, void *d)
+{
+	struct stack_trace_data *data = d;
+	struct stack_trace *trace = data->trace;
+	unsigned long addr = frame->pc;
+
+	if (data->no_sched_functions && in_sched_functions(addr))
+		return 0;
+	if (data->skip) {
+		data->skip--;
+		return 0;
+	}
+
+	trace->entries[trace->nr_entries++] = addr;
+
+	return trace->nr_entries >= trace->max_entries;
+}
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+	struct stack_trace_data data;
+	struct stackframe frame;
+
+	data.trace = trace;
+	data.skip = trace->skip;
+
+	if (tsk != current) {
+		data.no_sched_functions = 1;
+		frame.fp = thread_saved_fp(tsk);
+		frame.sp = thread_saved_sp(tsk);
+		frame.pc = thread_saved_pc(tsk);
+	} else {
+		data.no_sched_functions = 0;
+		frame.fp = (unsigned long)__builtin_frame_address(0);
+		frame.sp = current_stack_pointer;
+		frame.pc = (unsigned long)save_stack_trace_tsk;
+	}
+
+	walk_stackframe(&frame, save_trace, &data);
+	if (trace->nr_entries < trace->max_entries)
+		trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+
+void save_stack_trace(struct stack_trace *trace)
+{
+	save_stack_trace_tsk(current, trace);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+#endif

arch/arm64/kernel/suspend.c

@@ -0,0 +1,162 @@
+#include <linux/percpu.h>
+#include <linux/slab.h>
+#include <asm/cacheflush.h>
+#include <asm/cpu_ops.h>
+#include <asm/debug-monitors.h>
+#include <asm/pgtable.h>
+#include <asm/memory.h>
+#include <asm/mmu_context.h>
+#include <asm/smp_plat.h>
+#include <asm/suspend.h>
+#include <asm/tlbflush.h>
+
+extern int __cpu_suspend_enter(unsigned long arg, int (*fn)(unsigned long));
+/*
+ * This is called by __cpu_suspend_enter() to save the state, and do whatever
+ * flushing is required to ensure that when the CPU goes to sleep we have
+ * the necessary data available when the caches are not searched.
+ *
+ * ptr: CPU context virtual address
+ * save_ptr: address of the location where the context physical address
+ *           must be saved
+ */
+void notrace __cpu_suspend_save(struct cpu_suspend_ctx *ptr,
+				phys_addr_t *save_ptr)
+{
+	*save_ptr = virt_to_phys(ptr);
+
+	cpu_do_suspend(ptr);
+	/*
+	 * Only flush the context that must be retrieved with the MMU
+	 * off. VA primitives ensure the flush is applied to all
+	 * cache levels so context is pushed to DRAM.
+	 */
+	__flush_dcache_area(ptr, sizeof(*ptr));
+	__flush_dcache_area(save_ptr, sizeof(*save_ptr));
+}
+
+/*
+ * This hook is provided so that cpu_suspend code can restore HW
+ * breakpoints as early as possible in the resume path, before reenabling
+ * debug exceptions. Code cannot be run from a CPU PM notifier since by the
+ * time the notifier runs debug exceptions might have been enabled already,
+ * with HW breakpoints registers content still in an unknown state.
+ */
+void (*hw_breakpoint_restore)(void *);
+void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *))
+{
+	/* Prevent multiple restore hook initializations */
+	if (WARN_ON(hw_breakpoint_restore))
+		return;
+	hw_breakpoint_restore = hw_bp_restore;
+}
+
+/**
+ * cpu_suspend() - function to enter a low-power state
+ * @arg: argument to pass to CPU suspend operations
+ *
+ * Return: 0 on success, -EOPNOTSUPP if CPU suspend hook not initialized, CPU
+ * operations back-end error code otherwise.
+ */
+int cpu_suspend(unsigned long arg)
+{
+	int cpu = smp_processor_id();
+
+	/*
+	 * If cpu_ops have not been registered or suspend
+	 * has not been initialized, cpu_suspend call fails early.
+	 */
+	if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_suspend)
+		return -EOPNOTSUPP;
+	return cpu_ops[cpu]->cpu_suspend(arg);
+}
+
+/*
+ * __cpu_suspend
+ *
+ * arg: argument to pass to the finisher function
+ * fn: finisher function pointer
+ *
+ */
+int __cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
+{
+	struct mm_struct *mm = current->active_mm;
+	int ret;
+	unsigned long flags;
+
+	/*
+	 * From this point debug exceptions are disabled to prevent
+	 * updates to mdscr register (saved and restored along with
+	 * general purpose registers) from kernel debuggers.
+	 */
+	local_dbg_save(flags);
+
+	/*
+	 * mm context saved on the stack, it will be restored when
+	 * the cpu comes out of reset through the identity mapped
+	 * page tables, so that the thread address space is properly
+	 * set-up on function return.
+	 */
+	ret = __cpu_suspend_enter(arg, fn);
+	if (ret == 0) {
+		/*
+		 * We are resuming from reset with TTBR0_EL1 set to the
+		 * idmap to enable the MMU; restore the active_mm mappings in
+		 * TTBR0_EL1 unless the active_mm == &init_mm, in which case
+		 * the thread entered __cpu_suspend with TTBR0_EL1 set to
+		 * reserved TTBR0 page tables and should be restored as such.
+		 */
+		if (mm == &init_mm)
+			cpu_set_reserved_ttbr0();
+		else
+			cpu_switch_mm(mm->pgd, mm);
+
+		flush_tlb_all();
+
+		/*
+		 * Restore per-cpu offset before any kernel
+		 * subsystem relying on it has a chance to run.
+		 */
+		set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
+
+		/*
+		 * Restore HW breakpoint registers to sane values
+		 * before debug exceptions are possibly reenabled
+		 * through local_dbg_restore.
+		 */
+		if (hw_breakpoint_restore)
+			hw_breakpoint_restore(NULL);
+	}
+
+	/*
+	 * Restore pstate flags. OS lock and mdscr have been already
+	 * restored, so from this point onwards, debugging is fully
+	 * renabled if it was enabled when core started shutdown.
+	 */
+	local_dbg_restore(flags);
+
+	return ret;
+}
+
+struct sleep_save_sp sleep_save_sp;
+phys_addr_t sleep_idmap_phys;
+
+static int __init cpu_suspend_init(void)
+{
+	void *ctx_ptr;
+
+	/* ctx_ptr is an array of physical addresses */
+	ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(phys_addr_t), GFP_KERNEL);
+
+	if (WARN_ON(!ctx_ptr))
+		return -ENOMEM;
+
+	sleep_save_sp.save_ptr_stash = ctx_ptr;
+	sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
+	sleep_idmap_phys = virt_to_phys(idmap_pg_dir);
+	__flush_dcache_area(&sleep_save_sp, sizeof(struct sleep_save_sp));
+	__flush_dcache_area(&sleep_idmap_phys, sizeof(sleep_idmap_phys));
+
+	return 0;
+}
+early_initcall(cpu_suspend_init);

arch/arm64/kernel/sys.c

@@ -0,0 +1,56 @@
+/*
+ * AArch64-specific system calls implementation
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Catalin Marinas <catalin.marinas@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+
+asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
+			 unsigned long prot, unsigned long flags,
+			 unsigned long fd, off_t off)
+{
+	if (offset_in_page(off) != 0)
+		return -EINVAL;
+
+	return sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
+}
+
+/*
+ * Wrappers to pass the pt_regs argument.
+ */
+#define sys_rt_sigreturn	sys_rt_sigreturn_wrapper
+
+#include <asm/syscalls.h>
+
+#undef __SYSCALL
+#define __SYSCALL(nr, sym)	[nr] = sym,
+
+/*
+ * The sys_call_table array must be 4K aligned to be accessible from
+ * kernel/entry.S.
+ */
+void *sys_call_table[__NR_syscalls] __aligned(4096) = {
+	[0 ... __NR_syscalls - 1] = sys_ni_syscall,
+#include <asm/unistd.h>
+};

arch/arm64/kernel/sys32.S

@@ -0,0 +1,115 @@
+/*
+ * Compat system call wrappers
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Authors: Will Deacon <will.deacon@arm.com>
+ *	    Catalin Marinas <catalin.marinas@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/assembler.h>
+#include <asm/asm-offsets.h>
+
+/*
+ * System call wrappers for the AArch32 compatibility layer.
+ */
+
+compat_sys_sigreturn_wrapper:
+	mov	x0, sp
+	mov	x27, #0		// prevent syscall restart handling (why)
+	b	compat_sys_sigreturn
+ENDPROC(compat_sys_sigreturn_wrapper)
+
+compat_sys_rt_sigreturn_wrapper:
+	mov	x0, sp
+	mov	x27, #0		// prevent syscall restart handling (why)
+	b	compat_sys_rt_sigreturn
+ENDPROC(compat_sys_rt_sigreturn_wrapper)
+
+compat_sys_statfs64_wrapper:
+	mov	w3, #84
+	cmp	w1, #88
+	csel	w1, w3, w1, eq
+	b	compat_sys_statfs64
+ENDPROC(compat_sys_statfs64_wrapper)
+
+compat_sys_fstatfs64_wrapper:
+	mov	w3, #84
+	cmp	w1, #88
+	csel	w1, w3, w1, eq
+	b	compat_sys_fstatfs64
+ENDPROC(compat_sys_fstatfs64_wrapper)
+
+/*
+ * Wrappers for AArch32 syscalls that either take 64-bit parameters
+ * in registers or that take 32-bit parameters which require sign
+ * extension.
+ */
+compat_sys_pread64_wrapper:
+	regs_to_64	x3, x4, x5
+	b	sys_pread64
+ENDPROC(compat_sys_pread64_wrapper)
+
+compat_sys_pwrite64_wrapper:
+	regs_to_64	x3, x4, x5
+	b	sys_pwrite64
+ENDPROC(compat_sys_pwrite64_wrapper)
+
+compat_sys_truncate64_wrapper:
+	regs_to_64	x1, x2, x3
+	b	sys_truncate
+ENDPROC(compat_sys_truncate64_wrapper)
+
+compat_sys_ftruncate64_wrapper:
+	regs_to_64	x1, x2, x3
+	b	sys_ftruncate
+ENDPROC(compat_sys_ftruncate64_wrapper)
+
+compat_sys_readahead_wrapper:
+	regs_to_64	x1, x2, x3
+	mov	w2, w4
+	b	sys_readahead
+ENDPROC(compat_sys_readahead_wrapper)
+
+compat_sys_fadvise64_64_wrapper:
+	mov	w6, w1
+	regs_to_64	x1, x2, x3
+	regs_to_64	x2, x4, x5
+	mov	w3, w6
+	b	sys_fadvise64_64
+ENDPROC(compat_sys_fadvise64_64_wrapper)
+
+compat_sys_sync_file_range2_wrapper:
+	regs_to_64	x2, x2, x3
+	regs_to_64	x3, x4, x5
+	b	sys_sync_file_range2
+ENDPROC(compat_sys_sync_file_range2_wrapper)
+
+compat_sys_fallocate_wrapper:
+	regs_to_64	x2, x2, x3
+	regs_to_64	x3, x4, x5
+	b	sys_fallocate
+ENDPROC(compat_sys_fallocate_wrapper)
+
+#undef __SYSCALL
+#define __SYSCALL(x, y)		.quad	y	// x
+
+/*
+ * The system calls table must be 4KB aligned.
+ */
+	.align	12
+ENTRY(compat_sys_call_table)
+#include <asm/unistd32.h>

arch/arm64/kernel/sys_compat.c

@@ -0,0 +1,94 @@
+/*
+ * Based on arch/arm/kernel/sys_arm.c
+ *
+ * Copyright (C) People who wrote linux/arch/i386/kernel/sys_i386.c
+ * Copyright (C) 1995, 1996 Russell King.
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/compat.h>
+#include <linux/personality.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+
+#include <asm/cacheflush.h>
+#include <asm/unistd.h>
+
+static inline void
+do_compat_cache_op(unsigned long start, unsigned long end, int flags)
+{
+	struct mm_struct *mm = current->active_mm;
+	struct vm_area_struct *vma;
+
+	if (end < start || flags)
+		return;
+
+	down_read(&mm->mmap_sem);
+	vma = find_vma(mm, start);
+	if (vma && vma->vm_start < end) {
+		if (start < vma->vm_start)
+			start = vma->vm_start;
+		if (end > vma->vm_end)
+			end = vma->vm_end;
+		up_read(&mm->mmap_sem);
+		__flush_cache_user_range(start & PAGE_MASK, PAGE_ALIGN(end));
+		return;
+	}
+	up_read(&mm->mmap_sem);
+}
+
+/*
+ * Handle all unrecognised system calls.
+ */
+long compat_arm_syscall(struct pt_regs *regs)
+{
+	unsigned int no = regs->regs[7];
+
+	switch (no) {
+	/*
+	 * Flush a region from virtual address 'r0' to virtual address 'r1'
+	 * _exclusive_.  There is no alignment requirement on either address;
+	 * user space does not need to know the hardware cache layout.
+	 *
+	 * r2 contains flags.  It should ALWAYS be passed as ZERO until it
+	 * is defined to be something else.  For now we ignore it, but may
+	 * the fires of hell burn in your belly if you break this rule. ;)
+	 *
+	 * (at a later date, we may want to allow this call to not flush
+	 * various aspects of the cache.  Passing '0' will guarantee that
+	 * everything necessary gets flushed to maintain consistency in
+	 * the specified region).
+	 */
+	case __ARM_NR_compat_cacheflush:
+		do_compat_cache_op(regs->regs[0], regs->regs[1], regs->regs[2]);
+		return 0;
+
+	case __ARM_NR_compat_set_tls:
+		current->thread.tp_value = regs->regs[0];
+
+		/*
+		 * Protect against register corruption from context switch.
+		 * See comment in tls_thread_flush.
+		 */
+		barrier();
+		asm ("msr tpidrro_el0, %0" : : "r" (regs->regs[0]));
+		return 0;
+
+	default:
+		return -ENOSYS;
+	}
+}

arch/arm64/kernel/time.c

@@ -0,0 +1,81 @@
+/*
+ * Based on arch/arm/kernel/time.c
+ *
+ * Copyright (C) 1991, 1992, 1995  Linus Torvalds
+ * Modifications for ARM (C) 1994-2001 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/clockchips.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/timex.h>
+#include <linux/errno.h>
+#include <linux/profile.h>
+#include <linux/syscore_ops.h>
+#include <linux/timer.h>
+#include <linux/irq.h>
+#include <linux/delay.h>
+#include <linux/clocksource.h>
+#include <linux/clk-provider.h>
+
+#include <clocksource/arm_arch_timer.h>
+
+#include <asm/thread_info.h>
+#include <asm/stacktrace.h>
+
+#ifdef CONFIG_SMP
+unsigned long profile_pc(struct pt_regs *regs)
+{
+	struct stackframe frame;
+
+	if (!in_lock_functions(regs->pc))
+		return regs->pc;
+
+	frame.fp = regs->regs[29];
+	frame.sp = regs->sp;
+	frame.pc = regs->pc;
+	do {
+		int ret = unwind_frame(&frame);
+		if (ret < 0)
+			return 0;
+	} while (in_lock_functions(frame.pc));
+
+	return frame.pc;
+}
+EXPORT_SYMBOL(profile_pc);
+#endif
+
+void __init time_init(void)
+{
+	u32 arch_timer_rate;
+
+	of_clk_init(NULL);
+	clocksource_of_init();
+
+	tick_setup_hrtimer_broadcast();
+
+	arch_timer_rate = arch_timer_get_rate();
+	if (!arch_timer_rate)
+		panic("Unable to initialise architected timer.\n");
+
+	/* Calibrate the delay loop directly */
+	lpj_fine = arch_timer_rate / HZ;
+}

arch/arm64/kernel/topology.c

@@ -0,0 +1,620 @@
+/*
+ * arch/arm64/kernel/topology.c
+ *
+ * Copyright (C) 2011,2013,2014 Linaro Limited.
+ *
+ * Based on the arm32 version written by Vincent Guittot in turn based on
+ * arch/sh/kernel/topology.c
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/init.h>
+#include <linux/percpu.h>
+#include <linux/node.h>
+#include <linux/nodemask.h>
+#include <linux/of.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include <asm/cputype.h>
+#include <asm/topology.h>
+#include <asm/smp_plat.h>
+
+/*
+ * cpu power table
+ * This per cpu data structure describes the relative capacity of each core.
+ * On a heteregenous system, cores don't have the same computation capacity
+ * and we reflect that difference in the cpu_power field so the scheduler can
+ * take this difference into account during load balance. A per cpu structure
+ * is preferred because each CPU updates its own cpu_power field during the
+ * load balance except for idle cores. One idle core is selected to run the
+ * rebalance_domains for all idle cores and the cpu_power can be updated
+ * during this sequence.
+ */
+static DEFINE_PER_CPU(unsigned long, cpu_scale);
+
+unsigned long arch_scale_freq_power(struct sched_domain *sd, int cpu)
+{
+	return per_cpu(cpu_scale, cpu);
+}
+
+static void set_power_scale(unsigned int cpu, unsigned long power)
+{
+	per_cpu(cpu_scale, cpu) = power;
+}
+
+static int __init get_cpu_for_node(struct device_node *node)
+{
+	struct device_node *cpu_node;
+	int cpu;
+
+	cpu_node = of_parse_phandle(node, "cpu", 0);
+	if (!cpu_node)
+		return -1;
+
+	for_each_possible_cpu(cpu) {
+		if (of_get_cpu_node(cpu, NULL) == cpu_node) {
+			of_node_put(cpu_node);
+			return cpu;
+		}
+	}
+
+	pr_crit("Unable to find CPU node for %s\n", cpu_node->full_name);
+
+	of_node_put(cpu_node);
+	return -1;
+}
+
+static int __init parse_core(struct device_node *core, int cluster_id,
+			     int core_id)
+{
+	char name[10];
+	bool leaf = true;
+	int i = 0;
+	int cpu;
+	struct device_node *t;
+
+	do {
+		snprintf(name, sizeof(name), "thread%d", i);
+		t = of_get_child_by_name(core, name);
+		if (t) {
+			leaf = false;
+			cpu = get_cpu_for_node(t);
+			if (cpu >= 0) {
+				cpu_topology[cpu].cluster_id = cluster_id;
+				cpu_topology[cpu].core_id = core_id;
+				cpu_topology[cpu].thread_id = i;
+			} else {
+				pr_err("%s: Can't get CPU for thread\n",
+				       t->full_name);
+				of_node_put(t);
+				return -EINVAL;
+			}
+			of_node_put(t);
+		}
+		i++;
+	} while (t);
+
+	cpu = get_cpu_for_node(core);
+	if (cpu >= 0) {
+		if (!leaf) {
+			pr_err("%s: Core has both threads and CPU\n",
+			       core->full_name);
+			return -EINVAL;
+		}
+
+		cpu_topology[cpu].cluster_id = cluster_id;
+		cpu_topology[cpu].core_id = core_id;
+	} else if (leaf) {
+		pr_err("%s: Can't get CPU for leaf core\n", core->full_name);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int __init parse_cluster(struct device_node *cluster, int depth)
+{
+	char name[10];
+	bool leaf = true;
+	bool has_cores = false;
+	struct device_node *c;
+	static int cluster_id __initdata;
+	int core_id = 0;
+	int i, ret;
+
+	/*
+	 * First check for child clusters; we currently ignore any
+	 * information about the nesting of clusters and present the
+	 * scheduler with a flat list of them.
+	 */
+	i = 0;
+	do {
+		snprintf(name, sizeof(name), "cluster%d", i);
+		c = of_get_child_by_name(cluster, name);
+		if (c) {
+			leaf = false;
+			ret = parse_cluster(c, depth + 1);
+			of_node_put(c);
+			if (ret != 0)
+				return ret;
+		}
+		i++;
+	} while (c);
+
+	/* Now check for cores */
+	i = 0;
+	do {
+		snprintf(name, sizeof(name), "core%d", i);
+		c = of_get_child_by_name(cluster, name);
+		if (c) {
+			has_cores = true;
+
+			if (depth == 0) {
+				pr_err("%s: cpu-map children should be clusters\n",
+				       c->full_name);
+				of_node_put(c);
+				return -EINVAL;
+			}
+
+			if (leaf) {
+				ret = parse_core(c, cluster_id, core_id++);
+			} else {
+				pr_err("%s: Non-leaf cluster with core %s\n",
+				       cluster->full_name, name);
+				ret = -EINVAL;
+			}
+
+			of_node_put(c);
+			if (ret != 0)
+				return ret;
+		}
+		i++;
+	} while (c);
+
+	if (leaf && !has_cores)
+		pr_warn("%s: empty cluster\n", cluster->full_name);
+
+	if (leaf)
+		cluster_id++;
+
+	return 0;
+}
+
+struct cpu_efficiency {
+	const char *compatible;
+	unsigned long efficiency;
+};
+
+/*
+ * Table of relative efficiency of each processors
+ * The efficiency value must fit in 20bit and the final
+ * cpu_scale value must be in the range
+ *   0 < cpu_scale < 3*SCHED_POWER_SCALE/2
+ * in order to return at most 1 when DIV_ROUND_CLOSEST
+ * is used to compute the capacity of a CPU.
+ * Processors that are not defined in the table,
+ * use the default SCHED_POWER_SCALE value for cpu_scale.
+ */
+static const struct cpu_efficiency table_efficiency[] = {
+	{ "arm,mongoose", 4000 },	/* FIXME: temporary value */
+	{ "arm,cortex-a57", 3891 },
+	{ "arm,cortex-a53", 2048 },
+	{ NULL, },
+};
+
+static unsigned long *__cpu_capacity;
+#define cpu_capacity(cpu)	__cpu_capacity[cpu]
+
+static unsigned long middle_capacity = 1;
+
+/*
+ * Iterate all CPUs' descriptor in DT and compute the efficiency
+ * (as per table_efficiency). Also calculate a middle efficiency
+ * as close as possible to  (max{eff_i} - min{eff_i}) / 2
+ * This is later used to scale the cpu_power field such that an
+ * 'average' CPU is of middle power. Also see the comments near
+ * table_efficiency[] and update_cpu_power().
+ */
+static int __init parse_dt_topology(void)
+{
+	struct device_node *cn, *map;
+	int ret = 0;
+	int cpu;
+
+	cn = of_find_node_by_path("/cpus");
+	if (!cn) {
+		pr_err("No CPU information found in DT\n");
+		return 0;
+	}
+
+	/*
+	 * When topology is provided cpu-map is essentially a root
+	 * cluster with restricted subnodes.
+	 */
+	map = of_get_child_by_name(cn, "cpu-map");
+	if (!map)
+		goto out;
+
+	ret = parse_cluster(map, 0);
+	if (ret != 0)
+		goto out_map;
+
+	/*
+	 * Check that all cores are in the topology; the SMP code will
+	 * only mark cores described in the DT as possible.
+	 */
+	for_each_possible_cpu(cpu)
+		if (cpu_topology[cpu].cluster_id == -1)
+			ret = -EINVAL;
+
+out_map:
+	of_node_put(map);
+out:
+	of_node_put(cn);
+	return ret;
+}
+
+static void __init parse_dt_cpu_power(void)
+{
+	const struct cpu_efficiency *cpu_eff;
+	struct device_node *cn;
+	unsigned long min_capacity = ULONG_MAX;
+	unsigned long max_capacity = 0;
+	unsigned long capacity = 0;
+	int cpu;
+
+	__cpu_capacity = kcalloc(nr_cpu_ids, sizeof(*__cpu_capacity),
+				 GFP_NOWAIT);
+
+	for_each_possible_cpu(cpu) {
+		const u32 *rate;
+		int len;
+
+		/* Too early to use cpu->of_node */
+		cn = of_get_cpu_node(cpu, NULL);
+		if (!cn) {
+			pr_err("Missing device node for CPU %d\n", cpu);
+			continue;
+		}
+
+		for (cpu_eff = table_efficiency; cpu_eff->compatible; cpu_eff++)
+			if (of_device_is_compatible(cn, cpu_eff->compatible))
+				break;
+
+		if (cpu_eff->compatible == NULL) {
+			pr_warn("%s: Unknown CPU type\n", cn->full_name);
+			continue;
+		}
+
+		rate = of_get_property(cn, "clock-frequency", &len);
+		if (!rate || len != 4) {
+			pr_err("%s: Missing clock-frequency property\n",
+				cn->full_name);
+			continue;
+		}
+
+		capacity = ((be32_to_cpup(rate)) >> 20) * cpu_eff->efficiency;
+
+		/* Save min capacity of the system */
+		if (capacity < min_capacity)
+			min_capacity = capacity;
+
+		/* Save max capacity of the system */
+		if (capacity > max_capacity)
+			max_capacity = capacity;
+
+		cpu_capacity(cpu) = capacity;
+	}
+
+	/* If min and max capacities are equal we bypass the update of the
+	 * cpu_scale because all CPUs have the same capacity. Otherwise, we
+	 * compute a middle_capacity factor that will ensure that the capacity
+	 * of an 'average' CPU of the system will be as close as possible to
+	 * SCHED_POWER_SCALE, which is the default value, but with the
+	 * constraint explained near table_efficiency[].
+	 */
+	if (min_capacity == max_capacity)
+		return;
+	else if (4 * max_capacity < (3 * (max_capacity + min_capacity)))
+		middle_capacity = (min_capacity + max_capacity)
+				>> (SCHED_POWER_SHIFT+1);
+	else
+		middle_capacity = ((max_capacity / 3)
+				>> (SCHED_POWER_SHIFT-1)) + 1;
+}
+
+/*
+ * Look for a customed capacity of a CPU in the cpu_topo_data table during the
+ * boot. The update of all CPUs is in O(n^2) for heteregeneous system but the
+ * function returns directly for SMP system.
+ */
+static void update_cpu_power(unsigned int cpu)
+{
+	if (!cpu_capacity(cpu))
+		return;
+
+	set_power_scale(cpu, cpu_capacity(cpu) / middle_capacity);
+
+	pr_info("CPU%u: update cpu_power %lu\n",
+		cpu, arch_scale_freq_power(NULL, cpu));
+}
+
+/*
+ * cpu topology table
+ */
+struct cpu_topology cpu_topology[NR_CPUS];
+EXPORT_SYMBOL_GPL(cpu_topology);
+
+const struct cpumask *cpu_coregroup_mask(int cpu)
+{
+	return &cpu_topology[cpu].core_sibling;
+}
+
+static void update_siblings_masks(unsigned int cpuid)
+{
+	struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
+	int cpu;
+
+	/* update core and thread sibling masks */
+	for_each_possible_cpu(cpu) {
+		cpu_topo = &cpu_topology[cpu];
+
+		if (cpuid_topo->cluster_id != cpu_topo->cluster_id)
+			continue;
+
+		cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
+		if (cpu != cpuid)
+			cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
+
+		if (cpuid_topo->core_id != cpu_topo->core_id)
+			continue;
+
+		cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
+		if (cpu != cpuid)
+			cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
+	}
+}
+
+#ifdef CONFIG_SCHED_HMP
+
+/*
+ * Retrieve logical cpu index corresponding to a given MPIDR[23:0]
+ *  - mpidr: MPIDR[23:0] to be used for the look-up
+ *
+ * Returns the cpu logical index or -EINVAL on look-up error
+ */
+static inline int get_logical_index(u32 mpidr)
+{
+	int cpu;
+	for (cpu = 0; cpu < nr_cpu_ids; cpu++)
+		if (cpu_logical_map(cpu) == mpidr)
+			return cpu;
+	return -EINVAL;
+}
+
+static const char * const little_cores[] = {
+	"arm,cortex-a53",
+	NULL,
+};
+
+static bool is_little_cpu(struct device_node *cn)
+{
+	const char * const *lc;
+	for (lc = little_cores; *lc; lc++)
+		if (of_device_is_compatible(cn, *lc))
+			return true;
+	return false;
+}
+
+void __init arch_get_fast_and_slow_cpus(struct cpumask *fast,
+					struct cpumask *slow)
+{
+	struct device_node *cn = NULL;
+	int cpu;
+
+	cpumask_clear(fast);
+	cpumask_clear(slow);
+
+	/*
+	 * Use the config options if they are given. This helps testing
+	 * HMP scheduling on systems without a big.LITTLE architecture.
+	 */
+	if (strlen(CONFIG_HMP_FAST_CPU_MASK) && strlen(CONFIG_HMP_SLOW_CPU_MASK)) {
+		if (cpulist_parse(CONFIG_HMP_FAST_CPU_MASK, fast))
+			WARN(1, "Failed to parse HMP fast cpu mask!\n");
+		if (cpulist_parse(CONFIG_HMP_SLOW_CPU_MASK, slow))
+			WARN(1, "Failed to parse HMP slow cpu mask!\n");
+		return;
+	}
+
+	/*
+	 * Else, parse device tree for little cores.
+	 */
+	while ((cn = of_find_node_by_type(cn, "cpu"))) {
+
+		const u32 *mpidr;
+		int len;
+
+		mpidr = of_get_property(cn, "reg", &len);
+		if (!mpidr || len != 8) {
+			pr_err("%s missing reg property\n", cn->full_name);
+			continue;
+		}
+
+		cpu = get_logical_index(be32_to_cpup(mpidr+1));
+		if (cpu == -EINVAL) {
+			pr_err("couldn't get logical index for mpidr %x\n",
+							be32_to_cpup(mpidr+1));
+			break;
+		}
+
+		if (is_little_cpu(cn))
+			cpumask_set_cpu(cpu, slow);
+		else
+			cpumask_set_cpu(cpu, fast);
+	}
+
+	if (!cpumask_empty(fast) && !cpumask_empty(slow))
+		return;
+
+	/*
+	 * We didn't find both big and little cores so let's call all cores
+	 * fast as this will keep the system running, with all cores being
+	 * treated equal.
+	 */
+	cpumask_setall(fast);
+	cpumask_clear(slow);
+}
+
+struct cpumask hmp_slow_cpu_mask;
+struct cpumask hmp_fast_cpu_mask;
+
+void __init arch_get_hmp_domains(struct list_head *hmp_domains_list)
+{
+	struct hmp_domain *domain;
+
+	arch_get_fast_and_slow_cpus(&hmp_fast_cpu_mask, &hmp_slow_cpu_mask);
+
+	/*
+	 * Initialize hmp_domains
+	 * Must be ordered with respect to compute capacity.
+	 * Fastest domain at head of list.
+	 */
+	if(!cpumask_empty(&hmp_slow_cpu_mask)) {
+		domain = (struct hmp_domain *)
+			kmalloc(sizeof(struct hmp_domain), GFP_KERNEL);
+		cpumask_copy(&domain->possible_cpus, &hmp_slow_cpu_mask);
+		cpumask_and(&domain->cpus, cpu_online_mask, &domain->possible_cpus);
+		list_add(&domain->hmp_domains, hmp_domains_list);
+	}
+	domain = (struct hmp_domain *)
+		kmalloc(sizeof(struct hmp_domain), GFP_KERNEL);
+	cpumask_copy(&domain->possible_cpus, &hmp_fast_cpu_mask);
+	cpumask_and(&domain->cpus, cpu_online_mask, &domain->possible_cpus);
+	list_add(&domain->hmp_domains, hmp_domains_list);
+}
+#endif /* CONFIG_SCHED_HMP */
+
+/*
+ * cluster_to_logical_mask - return cpu logical mask of CPUs in a cluster
+ * @socket_id:		cluster HW identifier
+ * @cluster_mask:	the cpumask location to be initialized, modified by the
+ *			function only if return value == 0
+ *
+ * Return:
+ *
+ * 0 on success
+ * -EINVAL if cluster_mask is NULL or there is no record matching socket_id
+ */
+int cluster_to_logical_mask(unsigned int socket_id, cpumask_t *cluster_mask)
+{
+	int cpu;
+
+	if (!cluster_mask)
+		return -EINVAL;
+
+	for_each_online_cpu(cpu) {
+		if (socket_id == topology_physical_package_id(cpu)) {
+			cpumask_copy(cluster_mask, topology_core_cpumask(cpu));
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+void store_cpu_topology(unsigned int cpuid)
+{
+	struct cpu_topology *cpu_topo = &cpu_topology[cpuid];
+	unsigned int mpidr;
+
+	/* If the cpu topology has been already set, just return */
+	if (cpu_topo->core_id != -1)
+		return;
+
+	mpidr = read_cpuid_mpidr();
+
+	/* create cpu topology mapping */
+	if ((mpidr & MPIDR_SMP_BITMASK) == MPIDR_SMP_VALUE) {
+		/*
+		 * This is a multiprocessor system
+		 * multiprocessor format & multiprocessor mode field are set
+		 */
+		if (mpidr & MPIDR_MT_BITMASK) {
+			/* core performance interdependency */
+			cpu_topo->thread_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+			cpu_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+			cpu_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 2);
+		} else {
+			/* largely independent cores */
+			cpu_topo->thread_id = -1;
+			cpu_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+			cpu_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+		}
+	} else {
+		/*
+		 * This is an uniprocessor system
+		 * we are in multiprocessor format but uniprocessor system
+		 * or in the old uniprocessor format
+		 */
+		cpu_topo->thread_id = -1;
+		cpu_topo->core_id = 0;
+		cpu_topo->cluster_id = -1;
+	}
+
+	update_siblings_masks(cpuid);
+	update_cpu_power(cpuid);
+
+	pr_info("CPU%u: thread %d, cpu %d, cluster %d, mpidr %x\n",
+		cpuid, cpu_topology[cpuid].thread_id,
+		cpu_topology[cpuid].core_id,
+		cpu_topology[cpuid].cluster_id, mpidr);
+}
+
+
+static void __init reset_cpu_topology(void)
+{
+	unsigned int cpu;
+
+	for_each_possible_cpu(cpu) {
+		struct cpu_topology *cpu_topo = &cpu_topology[cpu];
+
+		cpu_topo->thread_id = -1;
+		cpu_topo->core_id = -1;
+		cpu_topo->cluster_id = -1;
+
+		cpumask_clear(&cpu_topo->core_sibling);
+		cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
+		cpumask_clear(&cpu_topo->thread_sibling);
+		cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
+	}
+}
+
+static void __init reset_cpu_power(void)
+{
+	unsigned int cpu;
+
+	for_each_possible_cpu(cpu)
+		set_power_scale(cpu, SCHED_POWER_SCALE);
+}
+
+void __init init_cpu_topology(void)
+{
+	reset_cpu_topology();
+
+	/*
+	 * Discard anything that was parsed if we hit an error so we
+	 * don't use partial information.
+	 */
+	if (parse_dt_topology())
+		reset_cpu_topology();
+
+	reset_cpu_power();
+	parse_dt_cpu_power();
+}

arch/arm64/kernel/trace-events-emulation.h

@@ -0,0 +1,35 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM emulation
+
+#if !defined(_TRACE_EMULATION_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_EMULATION_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(instruction_emulation,
+
+	TP_PROTO(const char *instr, u64 addr),
+	TP_ARGS(instr, addr),
+
+	TP_STRUCT__entry(
+		__string(instr, instr)
+		__field(u64, addr)
+	),
+
+	TP_fast_assign(
+		__assign_str(instr, instr);
+		__entry->addr = addr;
+	),
+
+	TP_printk("instr=\"%s\" addr=0x%llx", __get_str(instr), __entry->addr)
+);
+
+#endif /* _TRACE_EMULATION_H */
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_PATH
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_PATH .
+
+#define TRACE_INCLUDE_FILE trace-events-emulation
+#include <trace/define_trace.h>

arch/arm64/kernel/traps.c

@@ -0,0 +1,434 @@
+/*
+ * Based on arch/arm/kernel/traps.c
+ *
+ * Copyright (C) 1995-2009 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/signal.h>
+#include <linux/personality.h>
+#include <linux/kallsyms.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/hardirq.h>
+#include <linux/kdebug.h>
+#include <linux/module.h>
+#include <linux/kexec.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/syscalls.h>
+
+#include <asm/atomic.h>
+#include <asm/debug-monitors.h>
+#include <asm/traps.h>
+#include <asm/stacktrace.h>
+#include <asm/exception.h>
+#include <asm/system_misc.h>
+
+static const char *handler[]= {
+	"Synchronous Abort",
+	"IRQ",
+	"FIQ",
+	"Error"
+};
+
+int show_unhandled_signals = 1;
+
+/*
+ * Dump out the contents of some memory nicely...
+ */
+static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
+		     unsigned long top)
+{
+	unsigned long first;
+	mm_segment_t fs;
+	int i;
+
+	/*
+	 * We need to switch to kernel mode so that we can use __get_user
+	 * to safely read from kernel space.  Note that we now dump the
+	 * code first, just in case the backtrace kills us.
+	 */
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	printk("%s%s(0x%016lx to 0x%016lx)\n", lvl, str, bottom, top);
+
+	for (first = bottom & ~31; first < top; first += 32) {
+		unsigned long p;
+		char str[sizeof(" 12345678") * 8 + 1];
+
+		memset(str, ' ', sizeof(str));
+		str[sizeof(str) - 1] = '\0';
+
+		for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
+			if (p >= bottom && p < top) {
+				unsigned int val;
+				if (__get_user(val, (unsigned int *)p) == 0)
+					sprintf(str + i * 9, " %08x", val);
+				else
+					sprintf(str + i * 9, " ????????");
+			}
+		}
+		printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
+	}
+
+	set_fs(fs);
+}
+
+static void dump_backtrace_entry(unsigned long where, unsigned long stack)
+{
+	print_ip_sym(where);
+	if (in_exception_text(where))
+		dump_mem("", "Exception stack", stack,
+			 stack + sizeof(struct pt_regs));
+}
+
+static void dump_instr(const char *lvl, struct pt_regs *regs)
+{
+	unsigned long addr = instruction_pointer(regs);
+	mm_segment_t fs;
+	char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
+	int i;
+
+	/*
+	 * We need to switch to kernel mode so that we can use __get_user
+	 * to safely read from kernel space.  Note that we now dump the
+	 * code first, just in case the backtrace kills us.
+	 */
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	for (i = -4; i < 1; i++) {
+		unsigned int val, bad;
+
+		bad = __get_user(val, &((u32 *)addr)[i]);
+
+		if (!bad)
+			p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
+		else {
+			p += sprintf(p, "bad PC value");
+			break;
+		}
+	}
+	printk("%sCode: %s\n", lvl, str);
+
+	set_fs(fs);
+}
+
+static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
+{
+	struct stackframe frame;
+
+	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
+
+	if (!tsk)
+		tsk = current;
+
+	if (regs) {
+		frame.fp = regs->regs[29];
+		frame.sp = regs->sp;
+		frame.pc = regs->pc;
+	} else if (tsk == current) {
+		frame.fp = (unsigned long)__builtin_frame_address(0);
+		frame.sp = current_stack_pointer;
+		frame.pc = (unsigned long)dump_backtrace;
+	} else {
+		/*
+		 * task blocked in __switch_to
+		 */
+		frame.fp = thread_saved_fp(tsk);
+		frame.sp = thread_saved_sp(tsk);
+		frame.pc = thread_saved_pc(tsk);
+	}
+
+	pr_emerg("Call trace:\n");
+	while (1) {
+		unsigned long where = frame.pc;
+		int ret;
+
+		ret = unwind_frame(&frame);
+		if (ret < 0)
+			break;
+		dump_backtrace_entry(where, frame.sp);
+	}
+}
+
+void show_stack(struct task_struct *tsk, unsigned long *sp)
+{
+	dump_backtrace(NULL, tsk);
+	barrier();
+}
+
+#ifdef CONFIG_PREEMPT
+#define S_PREEMPT " PREEMPT"
+#else
+#define S_PREEMPT ""
+#endif
+#ifdef CONFIG_SMP
+#define S_SMP " SMP"
+#else
+#define S_SMP ""
+#endif
+
+static int __die(const char *str, int err, struct thread_info *thread,
+		 struct pt_regs *regs)
+{
+	struct task_struct *tsk = thread->task;
+	static int die_counter;
+	int ret;
+
+	pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
+		 str, err, ++die_counter);
+
+	/* trap and error numbers are mostly meaningless on ARM */
+	ret = notify_die(DIE_OOPS, str, regs, err, 0, SIGSEGV);
+	if (ret == NOTIFY_STOP)
+		return ret;
+
+	print_modules();
+	__show_regs(regs);
+	pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
+		 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1);
+
+	if (!user_mode(regs) || in_interrupt()) {
+		dump_mem(KERN_EMERG, "Stack: ", regs->sp,
+			 THREAD_SIZE + (unsigned long)task_stack_page(tsk));
+		dump_backtrace(regs, tsk);
+		dump_instr(KERN_EMERG, regs);
+	}
+
+	return ret;
+}
+
+static DEFINE_RAW_SPINLOCK(die_lock);
+
+/*
+ * This function is protected against re-entrancy.
+ */
+void die(const char *str, struct pt_regs *regs, int err)
+{
+	enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE;
+	struct thread_info *thread = current_thread_info();
+	int ret;
+
+	oops_enter();
+
+	raw_spin_lock_irq(&die_lock);
+	console_verbose();
+	bust_spinlocks(1);
+
+	if (!user_mode(regs))
+		bug_type = report_bug(regs->pc, regs);
+	if (bug_type != BUG_TRAP_TYPE_NONE)
+		str = "Oops - BUG";
+
+	ret = __die(str, err, thread, regs);
+#if 0
+	if (regs && kexec_should_crash(thread->task))
+		crash_kexec(regs);
+#endif
+	bust_spinlocks(0);
+	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
+	raw_spin_unlock_irq(&die_lock);
+	oops_exit();
+
+	if (in_interrupt())
+		panic("Fatal exception in interrupt");
+	if (panic_on_oops)
+		panic("Fatal exception");
+	if (ret != NOTIFY_STOP)
+		do_exit(SIGSEGV);
+}
+
+void arm64_notify_die(const char *str, struct pt_regs *regs,
+		      struct siginfo *info, int err)
+{
+	if (user_mode(regs)) {
+		current->thread.fault_address = 0;
+		current->thread.fault_code = err;
+		force_sig_info(info->si_signo, info, current);
+	} else {
+		die(str, regs, err);
+	}
+}
+
+static LIST_HEAD(undef_hook);
+static DEFINE_RAW_SPINLOCK(undef_lock);
+
+void register_undef_hook(struct undef_hook *hook)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&undef_lock, flags);
+	list_add(&hook->node, &undef_hook);
+	raw_spin_unlock_irqrestore(&undef_lock, flags);
+}
+
+void unregister_undef_hook(struct undef_hook *hook)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&undef_lock, flags);
+	list_del(&hook->node);
+	raw_spin_unlock_irqrestore(&undef_lock, flags);
+}
+
+static int call_undef_hook(struct pt_regs *regs)
+{
+	struct undef_hook *hook;
+	unsigned long flags;
+	u32 instr;
+	int (*fn)(struct pt_regs *regs, u32 instr) = NULL;
+	void __user *pc = (void __user *)instruction_pointer(regs);
+
+	if (!user_mode(regs))
+		return 1;
+
+	if (compat_thumb_mode(regs)) {
+		/* 16-bit Thumb instruction */
+		if (get_user(instr, (u16 __user *)pc))
+			goto exit;
+		instr = le16_to_cpu(instr);
+		if (aarch32_insn_is_wide(instr)) {
+			u32 instr2;
+
+			if (get_user(instr2, (u16 __user *)(pc + 2)))
+				goto exit;
+			instr2 = le16_to_cpu(instr2);
+			instr = (instr << 16) | instr2;
+		}
+	} else {
+		/* 32-bit ARM instruction */
+		if (get_user(instr, (u32 __user *)pc))
+			goto exit;
+		instr = le32_to_cpu(instr);
+	}
+
+	raw_spin_lock_irqsave(&undef_lock, flags);
+	list_for_each_entry(hook, &undef_hook, node)
+		if ((instr & hook->instr_mask) == hook->instr_val &&
+			(regs->pstate & hook->pstate_mask) == hook->pstate_val)
+			fn = hook->fn;
+
+	raw_spin_unlock_irqrestore(&undef_lock, flags);
+exit:
+	return fn ? fn(regs, instr) : 1;
+}
+
+#ifdef CONFIG_GENERIC_BUG
+int is_valid_bugaddr(unsigned long pc)
+{
+	return 1;
+}
+#endif
+
+asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
+{
+	siginfo_t info;
+	void __user *pc = (void __user *)instruction_pointer(regs);
+
+	/* check for AArch32 breakpoint instructions */
+	if (!aarch32_break_handler(regs))
+		return;
+
+	if (call_undef_hook(regs) == 0)
+		return;
+
+	if (show_unhandled_signals && unhandled_signal(current, SIGILL) &&
+	    printk_ratelimit()) {
+		pr_info("%s[%d]: undefined instruction: pc=%p\n",
+			current->comm, task_pid_nr(current), pc);
+		dump_instr(KERN_INFO, regs);
+	}
+
+	info.si_signo = SIGILL;
+	info.si_errno = 0;
+	info.si_code  = ILL_ILLOPC;
+	info.si_addr  = pc;
+
+	arm64_notify_die("Oops - undefined instruction", regs, &info, 0);
+}
+
+long compat_arm_syscall(struct pt_regs *regs);
+
+asmlinkage long do_ni_syscall(struct pt_regs *regs)
+{
+#ifdef CONFIG_COMPAT
+	long ret;
+	if (is_compat_task()) {
+		ret = compat_arm_syscall(regs);
+		if (ret != -ENOSYS)
+			return ret;
+	}
+#endif
+
+	if (show_unhandled_signals && printk_ratelimit()) {
+		pr_info("%s[%d]: syscall %d\n", current->comm,
+			task_pid_nr(current), (int)regs->syscallno);
+		dump_instr("", regs);
+		if (user_mode(regs))
+			__show_regs(regs);
+	}
+
+	return sys_ni_syscall();
+}
+
+/*
+ * bad_mode handles the impossible case in the exception vector.
+ */
+asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
+{
+	siginfo_t info;
+	void __user *pc = (void __user *)instruction_pointer(regs);
+	console_verbose();
+
+	pr_crit("Bad mode in %s handler detected, code 0x%08x\n",
+		handler[reason], esr);
+	__show_regs(regs);
+
+	info.si_signo = SIGILL;
+	info.si_errno = 0;
+	info.si_code  = ILL_ILLOPC;
+	info.si_addr  = pc;
+
+	arm64_notify_die("Oops - bad mode", regs, &info, 0);
+}
+
+void __pte_error(const char *file, int line, unsigned long val)
+{
+	pr_crit("%s:%d: bad pte %016lx.\n", file, line, val);
+}
+
+void __pmd_error(const char *file, int line, unsigned long val)
+{
+	pr_crit("%s:%d: bad pmd %016lx.\n", file, line, val);
+}
+
+void __pud_error(const char *file, int line, unsigned long val)
+{
+	pr_crit("%s:%d: bad pud %016lx.\n", file, line, val);
+}
+
+void __pgd_error(const char *file, int line, unsigned long val)
+{
+	pr_crit("%s:%d: bad pgd %016lx.\n", file, line, val);
+}
+
+void __init trap_init(void)
+{
+	return;
+}

arch/arm64/kernel/vdso.c

@@ -0,0 +1,231 @@
+/*
+ * VDSO implementation for AArch64 and vector page setup for AArch32.
+ *
+ * Copyright (C) 2012 ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/clocksource.h>
+#include <linux/elf.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <linux/slab.h>
+#include <linux/timekeeper_internal.h>
+#include <linux/vmalloc.h>
+
+#include <asm/cacheflush.h>
+#include <asm/signal32.h>
+#include <asm/vdso.h>
+#include <asm/vdso_datapage.h>
+
+extern char vdso_start, vdso_end;
+static unsigned long vdso_pages;
+static struct page **vdso_pagelist;
+
+/*
+ * The vDSO data page.
+ */
+static union {
+	struct vdso_data	data;
+	u8			page[PAGE_SIZE];
+} vdso_data_store __page_aligned_data;
+struct vdso_data *vdso_data = &vdso_data_store.data;
+
+#ifdef CONFIG_COMPAT
+/*
+ * Create and map the vectors page for AArch32 tasks.
+ */
+static struct page *vectors_page[1];
+
+static int alloc_vectors_page(void)
+{
+	extern char __kuser_helper_start[], __kuser_helper_end[];
+	extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];
+
+	int kuser_sz = __kuser_helper_end - __kuser_helper_start;
+	int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start;
+	unsigned long vpage;
+
+	vpage = get_zeroed_page(GFP_ATOMIC);
+
+	if (!vpage)
+		return -ENOMEM;
+
+	/* kuser helpers */
+	memcpy((void *)vpage + 0x1000 - kuser_sz, __kuser_helper_start,
+		kuser_sz);
+
+	/* sigreturn code */
+	memcpy((void *)vpage + AARCH32_KERN_SIGRET_CODE_OFFSET,
+               __aarch32_sigret_code_start, sigret_sz);
+
+	flush_icache_range(vpage, vpage + PAGE_SIZE);
+	vectors_page[0] = virt_to_page(vpage);
+
+	return 0;
+}
+arch_initcall(alloc_vectors_page);
+
+int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
+{
+	struct mm_struct *mm = current->mm;
+	unsigned long addr = AARCH32_VECTORS_BASE;
+	static struct vm_special_mapping spec = {
+		.name	= "[vectors]",
+		.pages	= vectors_page,
+
+	};
+	void *ret;
+
+	down_write(&mm->mmap_sem);
+	current->mm->context.vdso = (void *)addr;
+
+	/* Map vectors page at the high address. */
+	ret = _install_special_mapping(mm, addr, PAGE_SIZE,
+				       VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC,
+				       &spec);
+
+	up_write(&mm->mmap_sem);
+
+	return PTR_ERR_OR_ZERO(ret);
+}
+#endif /* CONFIG_COMPAT */
+
+static struct vm_special_mapping vdso_spec[2];
+
+static int __init vdso_init(void)
+{
+	int i;
+
+	if (memcmp(&vdso_start, "\177ELF", 4)) {
+		pr_err("vDSO is not a valid ELF object!\n");
+		return -EINVAL;
+	}
+
+	vdso_pages = (&vdso_end - &vdso_start) >> PAGE_SHIFT;
+	pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n",
+		vdso_pages + 1, vdso_pages, &vdso_start, 1L, vdso_data);
+
+	/* Allocate the vDSO pagelist, plus a page for the data. */
+	vdso_pagelist = kcalloc(vdso_pages + 1, sizeof(struct page *),
+				GFP_KERNEL);
+	if (vdso_pagelist == NULL)
+		return -ENOMEM;
+
+	/* Grab the vDSO data page. */
+	vdso_pagelist[0] = virt_to_page(vdso_data);
+
+	/* Grab the vDSO code pages. */
+	for (i = 0; i < vdso_pages; i++)
+		vdso_pagelist[i + 1] = virt_to_page(&vdso_start + i * PAGE_SIZE);
+
+	/* Populate the special mapping structures */
+	vdso_spec[0] = (struct vm_special_mapping) {
+		.name	= "[vvar]",
+		.pages	= vdso_pagelist,
+	};
+
+	vdso_spec[1] = (struct vm_special_mapping) {
+		.name	= "[vdso]",
+		.pages	= &vdso_pagelist[1],
+	};
+
+	return 0;
+}
+arch_initcall(vdso_init);
+
+int arch_setup_additional_pages(struct linux_binprm *bprm,
+				int uses_interp)
+{
+	struct mm_struct *mm = current->mm;
+	unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
+	void *ret;
+
+	vdso_text_len = vdso_pages << PAGE_SHIFT;
+	/* Be sure to map the data page */
+	vdso_mapping_len = vdso_text_len + PAGE_SIZE;
+
+	down_write(&mm->mmap_sem);
+	vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
+	if (IS_ERR_VALUE(vdso_base)) {
+		ret = ERR_PTR(vdso_base);
+		goto up_fail;
+	}
+	ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE,
+				       VM_READ|VM_MAYREAD,
+				       &vdso_spec[0]);
+	if (IS_ERR(ret))
+		goto up_fail;
+
+	vdso_base += PAGE_SIZE;
+	mm->context.vdso = (void *)vdso_base;
+	ret = _install_special_mapping(mm, vdso_base, vdso_text_len,
+				       VM_READ|VM_EXEC|
+				       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
+				       &vdso_spec[1]);
+	if (IS_ERR(ret))
+		goto up_fail;
+
+
+	up_write(&mm->mmap_sem);
+	return 0;
+
+up_fail:
+	mm->context.vdso = NULL;
+	up_write(&mm->mmap_sem);
+	return PTR_ERR(ret);
+}
+
+/*
+ * Update the vDSO data page to keep in sync with kernel timekeeping.
+ */
+void update_vsyscall(struct timekeeper *tk)
+{
+	struct timespec xtime_coarse;
+	u32 use_syscall = strcmp(tk->tkr.clock->name, "arch_sys_counter");
+
+	++vdso_data->tb_seq_count;
+	smp_wmb();
+
+	xtime_coarse = __current_kernel_time();
+	vdso_data->use_syscall			= use_syscall;
+	vdso_data->xtime_coarse_sec		= xtime_coarse.tv_sec;
+	vdso_data->xtime_coarse_nsec		= xtime_coarse.tv_nsec;
+	vdso_data->wtm_clock_sec		= tk->wall_to_monotonic.tv_sec;
+	vdso_data->wtm_clock_nsec		= tk->wall_to_monotonic.tv_nsec;
+
+	if (!use_syscall) {
+		vdso_data->cs_cycle_last	= tk->tkr.cycle_last;
+		vdso_data->xtime_clock_sec	= tk->xtime_sec;
+		vdso_data->xtime_clock_nsec	= tk->tkr.xtime_nsec;
+		vdso_data->cs_mult		= tk->tkr.mult;
+		vdso_data->cs_shift		= tk->tkr.shift;
+	}
+
+	smp_wmb();
+	++vdso_data->tb_seq_count;
+}
+
+void update_vsyscall_tz(void)
+{
+	vdso_data->tz_minuteswest	= sys_tz.tz_minuteswest;
+	vdso_data->tz_dsttime		= sys_tz.tz_dsttime;
+}

arch/arm64/kernel/vdso/Makefile

@@ -0,0 +1,63 @@
+#
+# Building a vDSO image for AArch64.
+#
+# Author: Will Deacon <will.deacon@arm.com>
+# Heavily based on the vDSO Makefiles for other archs.
+#
+
+obj-vdso := gettimeofday.o note.o sigreturn.o
+
+# Build rules
+targets := $(obj-vdso) vdso.so vdso.so.dbg
+obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
+
+ccflags-y := -shared -fno-common -fno-builtin
+ccflags-y += -nostdlib -Wl,-soname=linux-vdso.so.1 \
+		$(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
+
+obj-y += vdso.o
+extra-y += vdso.lds vdso-offsets.h
+CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
+
+# Force dependency (incbin is bad)
+$(obj)/vdso.o : $(obj)/vdso.so
+
+# Link rule for the .so file, .lds has to be first
+$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso)
+	$(call if_changed,vdsold)
+
+# Strip rule for the .so file
+$(obj)/%.so: OBJCOPYFLAGS := -S
+$(obj)/%.so: $(obj)/%.so.dbg FORCE
+	$(call if_changed,objcopy)
+
+# Generate VDSO offsets using helper script
+gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
+quiet_cmd_vdsosym = VDSOSYM $@
+define cmd_vdsosym
+	$(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ && \
+	cp $@ include/generated/
+endef
+
+$(obj)/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
+	$(call if_changed,vdsosym)
+
+# Assembly rules for the .S files
+$(obj-vdso): %.o: %.S FORCE
+	$(call if_changed_dep,vdsoas)
+
+# Actual build commands
+quiet_cmd_vdsold = VDSOL   $@
+      cmd_vdsold = $(CC) $(c_flags) -Wl,-n -Wl,-T $^ -o $@
+quiet_cmd_vdsoas = VDSOA   $@
+      cmd_vdsoas = $(CC) $(a_flags) -c -o $@ $<
+
+# Install commands for the unstripped file
+quiet_cmd_vdso_install = INSTALL $@
+      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
+
+vdso.so: $(obj)/vdso.so.dbg
+	@mkdir -p $(MODLIB)/vdso
+	$(call cmd,vdso_install)
+
+vdso_install: vdso.so

arch/arm64/kernel/vdso/gen_vdso_offsets.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+
+#
+# Match symbols in the DSO that look like VDSO_*; produce a header file
+# of constant offsets into the shared object.
+#
+# Doing this inside the Makefile will break the $(filter-out) function,
+# causing Kbuild to rebuild the vdso-offsets header file every time.
+#
+# Author: Will Deacon <will.deacon@arm.com
+#
+
+LC_ALL=C
+sed -n -e 's/^00*/0/' -e \
+'s/^\([0-9a-fA-F]*\) . VDSO_\([a-zA-Z0-9_]*\)$/\#define vdso_offset_\2\t0x\1/p'

arch/arm64/kernel/vdso/gettimeofday.S

@@ -0,0 +1,249 @@
+/*
+ * Userspace implementations of gettimeofday() and friends.
+ *
+ * Copyright (C) 2012 ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/unistd.h>
+
+#define NSEC_PER_SEC_LO16	0xca00
+#define NSEC_PER_SEC_HI16	0x3b9a
+
+vdso_data	.req	x6
+use_syscall	.req	w7
+seqcnt		.req	w8
+
+	.macro	seqcnt_acquire
+9999:	ldr	seqcnt, [vdso_data, #VDSO_TB_SEQ_COUNT]
+	tbnz	seqcnt, #0, 9999b
+	dmb	ishld
+	ldr	use_syscall, [vdso_data, #VDSO_USE_SYSCALL]
+	.endm
+
+	.macro	seqcnt_read, cnt
+	dmb	ishld
+	ldr	\cnt, [vdso_data, #VDSO_TB_SEQ_COUNT]
+	.endm
+
+	.macro	seqcnt_check, cnt, fail
+	cmp	\cnt, seqcnt
+	b.ne	\fail
+	.endm
+
+	.text
+
+/* int __kernel_gettimeofday(struct timeval *tv, struct timezone *tz); */
+ENTRY(__kernel_gettimeofday)
+	.cfi_startproc
+	mov	x2, x30
+	.cfi_register x30, x2
+
+	/* Acquire the sequence counter and get the timespec. */
+	adr	vdso_data, _vdso_data
+1:	seqcnt_acquire
+	cbnz	use_syscall, 4f
+
+	/* If tv is NULL, skip to the timezone code. */
+	cbz	x0, 2f
+	bl	__do_get_tspec
+	seqcnt_check w9, 1b
+
+	/* Convert ns to us. */
+	mov	x13, #1000
+	lsl	x13, x13, x12
+	udiv	x11, x11, x13
+	stp	x10, x11, [x0, #TVAL_TV_SEC]
+2:
+	/* If tz is NULL, return 0. */
+	cbz	x1, 3f
+	ldp	w4, w5, [vdso_data, #VDSO_TZ_MINWEST]
+	stp	w4, w5, [x1, #TZ_MINWEST]
+3:
+	mov	x0, xzr
+	ret	x2
+4:
+	/* Syscall fallback. */
+	mov	x8, #__NR_gettimeofday
+	svc	#0
+	ret	x2
+	.cfi_endproc
+ENDPROC(__kernel_gettimeofday)
+
+/* int __kernel_clock_gettime(clockid_t clock_id, struct timespec *tp); */
+ENTRY(__kernel_clock_gettime)
+	.cfi_startproc
+	cmp	w0, #CLOCK_REALTIME
+	ccmp	w0, #CLOCK_MONOTONIC, #0x4, ne
+	b.ne	2f
+
+	mov	x2, x30
+	.cfi_register x30, x2
+
+	/* Get kernel timespec. */
+	adr	vdso_data, _vdso_data
+1:	seqcnt_acquire
+	cbnz	use_syscall, 7f
+
+	bl	__do_get_tspec
+	seqcnt_check w9, 1b
+
+	mov	x30, x2
+
+	cmp	w0, #CLOCK_MONOTONIC
+	b.ne	6f
+
+	/* Get wtm timespec. */
+	ldp	x13, x14, [vdso_data, #VDSO_WTM_CLK_SEC]
+
+	/* Check the sequence counter. */
+	seqcnt_read w9
+	seqcnt_check w9, 1b
+	b	4f
+2:
+	cmp	w0, #CLOCK_REALTIME_COARSE
+	ccmp	w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne
+	b.ne	8f
+
+	/* xtime_coarse_nsec is already right-shifted */
+	mov	x12, #0
+
+	/* Get coarse timespec. */
+	adr	vdso_data, _vdso_data
+3:	seqcnt_acquire
+	ldp	x10, x11, [vdso_data, #VDSO_XTIME_CRS_SEC]
+
+	/* Get wtm timespec. */
+	ldp	x13, x14, [vdso_data, #VDSO_WTM_CLK_SEC]
+
+	/* Check the sequence counter. */
+	seqcnt_read w9
+	seqcnt_check w9, 3b
+
+	cmp	w0, #CLOCK_MONOTONIC_COARSE
+	b.ne	6f
+4:
+	/* Add on wtm timespec. */
+	add	x10, x10, x13
+	lsl	x14, x14, x12
+	add	x11, x11, x14
+
+	/* Normalise the new timespec. */
+	mov	x15, #NSEC_PER_SEC_LO16
+	movk	x15, #NSEC_PER_SEC_HI16, lsl #16
+	lsl	x15, x15, x12
+	cmp	x11, x15
+	b.lt	5f
+	sub	x11, x11, x15
+	add	x10, x10, #1
+5:
+	cmp	x11, #0
+	b.ge	6f
+	add	x11, x11, x15
+	sub	x10, x10, #1
+
+6:	/* Store to the user timespec. */
+	lsr	x11, x11, x12
+	stp	x10, x11, [x1, #TSPEC_TV_SEC]
+	mov	x0, xzr
+	ret
+7:
+	mov	x30, x2
+8:	/* Syscall fallback. */
+	mov	x8, #__NR_clock_gettime
+	svc	#0
+	ret
+	.cfi_endproc
+ENDPROC(__kernel_clock_gettime)
+
+/* int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); */
+ENTRY(__kernel_clock_getres)
+	.cfi_startproc
+	cbz	w1, 3f
+
+	cmp	w0, #CLOCK_REALTIME
+	ccmp	w0, #CLOCK_MONOTONIC, #0x4, ne
+	b.ne	1f
+
+	ldr	x2, 5f
+	b	2f
+1:
+	cmp	w0, #CLOCK_REALTIME_COARSE
+	ccmp	w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne
+	b.ne	4f
+	ldr	x2, 6f
+2:
+	stp	xzr, x2, [x1]
+
+3:	/* res == NULL. */
+	mov	w0, wzr
+	ret
+
+4:	/* Syscall fallback. */
+	mov	x8, #__NR_clock_getres
+	svc	#0
+	ret
+5:
+	.quad	CLOCK_REALTIME_RES
+6:
+	.quad	CLOCK_COARSE_RES
+	.cfi_endproc
+ENDPROC(__kernel_clock_getres)
+
+/*
+ * Read the current time from the architected counter.
+ * Expects vdso_data to be initialised.
+ * Clobbers the temporary registers (x9 - x15).
+ * Returns:
+ *  - w9		= vDSO sequence counter
+ *  - (x10, x11)	= (ts->tv_sec, shifted ts->tv_nsec)
+ *  - w12		= cs_shift
+ */
+ENTRY(__do_get_tspec)
+	.cfi_startproc
+
+	/* Read from the vDSO data page. */
+	ldr	x10, [vdso_data, #VDSO_CS_CYCLE_LAST]
+	ldp	x13, x14, [vdso_data, #VDSO_XTIME_CLK_SEC]
+	ldp	w11, w12, [vdso_data, #VDSO_CS_MULT]
+	seqcnt_read w9
+
+	/* Read the virtual counter. */
+	isb
+	mrs	x15, cntvct_el0
+
+	/* Calculate cycle delta and convert to ns. */
+	sub	x10, x15, x10
+	/* We can only guarantee 56 bits of precision. */
+	movn	x15, #0xff00, lsl #48
+	and	x10, x15, x10
+	mul	x10, x10, x11
+
+	/* Use the kernel time to calculate the new timespec. */
+	mov	x11, #NSEC_PER_SEC_LO16
+	movk	x11, #NSEC_PER_SEC_HI16, lsl #16
+	lsl	x11, x11, x12
+	add	x15, x10, x14
+	udiv	x14, x15, x11
+	add	x10, x13, x14
+	mul	x13, x14, x11
+	sub	x11, x15, x13
+
+	ret
+	.cfi_endproc
+ENDPROC(__do_get_tspec)

arch/arm64/kernel/vdso/note.S

@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2012 ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ *
+ * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
+ * Here we can supply some information useful to userland.
+ */
+
+#include <linux/uts.h>
+#include <linux/version.h>
+#include <linux/elfnote.h>
+
+ELFNOTE_START(Linux, 0, "a")
+	.long LINUX_VERSION_CODE
+ELFNOTE_END

arch/arm64/kernel/vdso/sigreturn.S

@@ -0,0 +1,37 @@
+/*
+ * Sigreturn trampoline for returning from a signal when the SA_RESTORER
+ * flag is not set.
+ *
+ * Copyright (C) 2012 ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#include <linux/linkage.h>
+#include <asm/unistd.h>
+
+	.text
+
+	nop
+ENTRY(__kernel_rt_sigreturn)
+	.cfi_startproc
+	.cfi_signal_frame
+	.cfi_def_cfa	x29, 0
+	.cfi_offset	x29, 0 * 8
+	.cfi_offset	x30, 1 * 8
+	mov	x8, #__NR_rt_sigreturn
+	svc	#0
+	.cfi_endproc
+ENDPROC(__kernel_rt_sigreturn)

arch/arm64/kernel/vdso/vdso.S

@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2012 ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <linux/const.h>
+#include <asm/page.h>
+
+	__PAGE_ALIGNED_DATA
+
+	.globl vdso_start, vdso_end
+	.balign PAGE_SIZE
+vdso_start:
+	.incbin "arch/arm64/kernel/vdso/vdso.so"
+	.balign PAGE_SIZE
+vdso_end:
+
+	.previous

arch/arm64/kernel/vdso/vdso.lds.S

@@ -0,0 +1,98 @@
+/*
+ * GNU linker script for the VDSO library.
+*
+ * Copyright (C) 2012 ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ * Heavily based on the vDSO linker scripts for other archs.
+ */
+
+#include <linux/const.h>
+#include <asm/page.h>
+#include <asm/vdso.h>
+
+OUTPUT_FORMAT("elf64-littleaarch64", "elf64-bigaarch64", "elf64-littleaarch64")
+OUTPUT_ARCH(aarch64)
+
+SECTIONS
+{
+	PROVIDE(_vdso_data = . - PAGE_SIZE);
+	. = VDSO_LBASE + SIZEOF_HEADERS;
+
+	.hash		: { *(.hash) }			:text
+	.gnu.hash	: { *(.gnu.hash) }
+	.dynsym		: { *(.dynsym) }
+	.dynstr		: { *(.dynstr) }
+	.gnu.version	: { *(.gnu.version) }
+	.gnu.version_d	: { *(.gnu.version_d) }
+	.gnu.version_r	: { *(.gnu.version_r) }
+
+	.note		: { *(.note.*) }		:text	:note
+
+	. = ALIGN(16);
+
+	.text		: { *(.text*) }			:text	=0xd503201f
+	PROVIDE (__etext = .);
+	PROVIDE (_etext = .);
+	PROVIDE (etext = .);
+
+	.eh_frame_hdr	: { *(.eh_frame_hdr) }		:text	:eh_frame_hdr
+	.eh_frame	: { KEEP (*(.eh_frame)) }	:text
+
+	.dynamic	: { *(.dynamic) }		:text	:dynamic
+
+	.rodata		: { *(.rodata*) }		:text
+
+	_end = .;
+	PROVIDE(end = .);
+
+	/DISCARD/	: {
+		*(.note.GNU-stack)
+		*(.data .data.* .gnu.linkonce.d.* .sdata*)
+		*(.bss .sbss .dynbss .dynsbss)
+	}
+}
+
+/*
+ * We must supply the ELF program headers explicitly to get just one
+ * PT_LOAD segment, and set the flags explicitly to make segments read-only.
+ */
+PHDRS
+{
+	text		PT_LOAD		FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
+	dynamic		PT_DYNAMIC	FLAGS(4);		/* PF_R */
+	note		PT_NOTE		FLAGS(4);		/* PF_R */
+	eh_frame_hdr	PT_GNU_EH_FRAME;
+}
+
+/*
+ * This controls what symbols we export from the DSO.
+ */
+VERSION
+{
+	LINUX_2.6.39 {
+	global:
+		__kernel_rt_sigreturn;
+		__kernel_gettimeofday;
+		__kernel_clock_gettime;
+		__kernel_clock_getres;
+	local: *;
+	};
+}
+
+/*
+ * Make the sigreturn code visible to the kernel.
+ */
+VDSO_sigtramp		= __kernel_rt_sigreturn;

arch/arm64/kernel/vmlinux.lds.S

@@ -0,0 +1,169 @@
+/*
+ * ld script to make ARM Linux kernel
+ * taken from the i386 version by Russell King
+ * Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
+ */
+
+#include <asm-generic/vmlinux.lds.h>
+#include <asm/thread_info.h>
+#include <asm/memory.h>
+#include <asm/page.h>
+
+#include "image.h"
+
+/* .exit.text needed in case of alternative patching */
+#if (defined(CONFIG_GENERIC_BUG))
+#define ARM_EXIT_KEEP(x)        x
+#define ARM_EXIT_DISCARD(x)
+#else
+#define ARM_EXIT_KEEP(x)
+#define ARM_EXIT_DISCARD(x)	x
+#endif
+
+OUTPUT_ARCH(aarch64)
+ENTRY(_text)
+
+jiffies = jiffies_64;
+
+#define HYPERVISOR_TEXT					\
+	/*						\
+	 * Force the alignment to be compatible with	\
+	 * the vectors requirements			\
+	 */						\
+	. = ALIGN(2048);				\
+	VMLINUX_SYMBOL(__hyp_idmap_text_start) = .;	\
+	*(.hyp.idmap.text)				\
+	VMLINUX_SYMBOL(__hyp_idmap_text_end) = .;	\
+	VMLINUX_SYMBOL(__hyp_text_start) = .;		\
+	*(.hyp.text)					\
+	VMLINUX_SYMBOL(__hyp_text_end) = .;
+
+SECTIONS
+{
+	/*
+	 * XXX: The linker does not define how output sections are
+	 * assigned to input sections when there are multiple statements
+	 * matching the same input section name.  There is no documented
+	 * order of matching.
+	 */
+	/DISCARD/ : {
+		ARM_EXIT_DISCARD(EXIT_TEXT)
+		ARM_EXIT_DISCARD(EXIT_DATA)
+		EXIT_CALL
+		*(.discard)
+		*(.discard.*)
+	}
+
+	. = PAGE_OFFSET + TEXT_OFFSET;
+
+	.head.text : {
+		_text = .;
+		HEAD_TEXT
+	}
+	.text : {			/* Real text segment		*/
+		_stext = .;		/* Text and read-only data	*/
+			__exception_text_start = .;
+			*(.exception.text)
+			__exception_text_end = .;
+			IRQENTRY_TEXT
+			TEXT_TEXT
+			SCHED_TEXT
+			LOCK_TEXT
+			HYPERVISOR_TEXT
+			*(.fixup)
+			*(.gnu.warning)
+		. = ALIGN(16);
+		*(.got)			/* Global offset table		*/
+	}
+
+	RO_DATA(PAGE_SIZE)
+	EXCEPTION_TABLE(8)
+	NOTES
+#ifdef CONFIG_TIMA_RKP
+	. = ALIGN(PAGE_SIZE);
+	.rkp.bitmap : {
+		rkp_pgt_bitmap = .;
+		. = rkp_pgt_bitmap + 0x18000;
+	}
+	.rkp.dblmap : {
+		rkp_map_bitmap = .;
+		. = rkp_map_bitmap + 0x18000;
+	}
+
+	.vmm : { *(.vmm*) }
+	. = ALIGN(PAGE_SIZE);
+	idmap_pg_dir = .;
+	. += IDMAP_DIR_SIZE;
+	. = ALIGN(PAGE_SIZE);
+	swapper_pg_dir = .;
+	. += SWAPPER_DIR_SIZE;
+	. = ALIGN(PAGE_SIZE);
+#endif
+	_etext = .;			/* End of text and rodata section */
+
+	. = ALIGN(PAGE_SIZE);
+	__init_begin = .;
+
+	INIT_TEXT_SECTION(8)
+	.exit.text : {
+		ARM_EXIT_KEEP(EXIT_TEXT)
+	}
+	. = ALIGN(16);
+	.init.data : {
+		INIT_DATA
+		INIT_SETUP(16)
+		INIT_CALLS
+		CON_INITCALL
+		SECURITY_INITCALL
+		INIT_RAM_FS
+	}
+	.exit.data : {
+		ARM_EXIT_KEEP(EXIT_DATA)
+	}
+
+	PERCPU_SECTION(64)
+
+	. = ALIGN(PAGE_SIZE);
+	__init_end = .;
+
+	. = ALIGN(4);
+	.altinstructions : {
+		__alt_instructions = .;
+		*(.altinstructions)
+		__alt_instructions_end = .;
+	}
+	.altinstr_replacement : {
+		*(.altinstr_replacement)
+	}
+
+	. = ALIGN(PAGE_SIZE);
+	_data = .;
+	_sdata = .;
+	RW_DATA_SECTION(64, PAGE_SIZE, THREAD_SIZE)
+	_edata = .;
+
+	BSS_SECTION(0, 0, 0)
+#ifndef CONFIG_TIMA_RKP
+	. = ALIGN(PAGE_SIZE);
+	idmap_pg_dir = .;
+	. += IDMAP_DIR_SIZE;
+	swapper_pg_dir = .;
+	. += SWAPPER_DIR_SIZE;
+#endif
+	_end = .;
+
+	STABS_DEBUG
+
+	HEAD_SYMBOLS
+}
+
+/*
+ * The HYP init code can't be more than a page long.
+ */
+ASSERT(((__hyp_idmap_text_start + PAGE_SIZE) > __hyp_idmap_text_end),
+       "HYP init code too big")
+
+/*
+ * If padding is applied before .head.text, virt<->phys conversions will fail.
+ */
+ASSERT(_text == (PAGE_OFFSET + TEXT_OFFSET), "HEAD is misaligned")