Fixed MTP to work with TWRP

arch/x86/kernel/cpu/mcheck/Makefile

@@ -0,0 +1,11 @@
+obj-y				=  mce.o mce-severity.o
+
+obj-$(CONFIG_X86_ANCIENT_MCE)	+= winchip.o p5.o
+obj-$(CONFIG_X86_MCE_INTEL)	+= mce_intel.o
+obj-$(CONFIG_X86_MCE_AMD)	+= mce_amd.o
+obj-$(CONFIG_X86_MCE_THRESHOLD) += threshold.o
+obj-$(CONFIG_X86_MCE_INJECT)	+= mce-inject.o
+
+obj-$(CONFIG_X86_THERMAL_VECTOR) += therm_throt.o
+
+obj-$(CONFIG_ACPI_APEI)		+= mce-apei.o

arch/x86/kernel/cpu/mcheck/mce-apei.c

@@ -0,0 +1,155 @@
+/*
+ * Bridge between MCE and APEI
+ *
+ * On some machine, corrected memory errors are reported via APEI
+ * generic hardware error source (GHES) instead of corrected Machine
+ * Check. These corrected memory errors can be reported to user space
+ * through /dev/mcelog via faking a corrected Machine Check, so that
+ * the error memory page can be offlined by /sbin/mcelog if the error
+ * count for one page is beyond the threshold.
+ *
+ * For fatal MCE, save MCE record into persistent storage via ERST, so
+ * that the MCE record can be logged after reboot via ERST.
+ *
+ * Copyright 2010 Intel Corp.
+ *   Author: Huang Ying <ying.huang@intel.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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/cper.h>
+#include <acpi/apei.h>
+#include <acpi/ghes.h>
+#include <asm/mce.h>
+
+#include "mce-internal.h"
+
+void apei_mce_report_mem_error(int severity, struct cper_sec_mem_err *mem_err)
+{
+	struct mce m;
+
+	if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
+		return;
+
+	mce_setup(&m);
+	m.bank = 1;
+	/* Fake a memory read error with unknown channel */
+	m.status = MCI_STATUS_VAL | MCI_STATUS_EN | MCI_STATUS_ADDRV | 0x9f;
+
+	if (severity >= GHES_SEV_RECOVERABLE)
+		m.status |= MCI_STATUS_UC;
+	if (severity >= GHES_SEV_PANIC)
+		m.status |= MCI_STATUS_PCC;
+
+	m.addr = mem_err->physical_addr;
+	mce_log(&m);
+	mce_notify_irq();
+}
+EXPORT_SYMBOL_GPL(apei_mce_report_mem_error);
+
+#define CPER_CREATOR_MCE						\
+	UUID_LE(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c,	\
+		0x64, 0x90, 0xb8, 0x9d)
+#define CPER_SECTION_TYPE_MCE						\
+	UUID_LE(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,	\
+		0x04, 0x4a, 0x38, 0xfc)
+
+/*
+ * CPER specification (in UEFI specification 2.3 appendix N) requires
+ * byte-packed.
+ */
+struct cper_mce_record {
+	struct cper_record_header hdr;
+	struct cper_section_descriptor sec_hdr;
+	struct mce mce;
+} __packed;
+
+int apei_write_mce(struct mce *m)
+{
+	struct cper_mce_record rcd;
+
+	memset(&rcd, 0, sizeof(rcd));
+	memcpy(rcd.hdr.signature, CPER_SIG_RECORD, CPER_SIG_SIZE);
+	rcd.hdr.revision = CPER_RECORD_REV;
+	rcd.hdr.signature_end = CPER_SIG_END;
+	rcd.hdr.section_count = 1;
+	rcd.hdr.error_severity = CPER_SEV_FATAL;
+	/* timestamp, platform_id, partition_id are all invalid */
+	rcd.hdr.validation_bits = 0;
+	rcd.hdr.record_length = sizeof(rcd);
+	rcd.hdr.creator_id = CPER_CREATOR_MCE;
+	rcd.hdr.notification_type = CPER_NOTIFY_MCE;
+	rcd.hdr.record_id = cper_next_record_id();
+	rcd.hdr.flags = CPER_HW_ERROR_FLAGS_PREVERR;
+
+	rcd.sec_hdr.section_offset = (void *)&rcd.mce - (void *)&rcd;
+	rcd.sec_hdr.section_length = sizeof(rcd.mce);
+	rcd.sec_hdr.revision = CPER_SEC_REV;
+	/* fru_id and fru_text is invalid */
+	rcd.sec_hdr.validation_bits = 0;
+	rcd.sec_hdr.flags = CPER_SEC_PRIMARY;
+	rcd.sec_hdr.section_type = CPER_SECTION_TYPE_MCE;
+	rcd.sec_hdr.section_severity = CPER_SEV_FATAL;
+
+	memcpy(&rcd.mce, m, sizeof(*m));
+
+	return erst_write(&rcd.hdr);
+}
+
+ssize_t apei_read_mce(struct mce *m, u64 *record_id)
+{
+	struct cper_mce_record rcd;
+	int rc, pos;
+
+	rc = erst_get_record_id_begin(&pos);
+	if (rc)
+		return rc;
+retry:
+	rc = erst_get_record_id_next(&pos, record_id);
+	if (rc)
+		goto out;
+	/* no more record */
+	if (*record_id == APEI_ERST_INVALID_RECORD_ID)
+		goto out;
+	rc = erst_read(*record_id, &rcd.hdr, sizeof(rcd));
+	/* someone else has cleared the record, try next one */
+	if (rc == -ENOENT)
+		goto retry;
+	else if (rc < 0)
+		goto out;
+	/* try to skip other type records in storage */
+	else if (rc != sizeof(rcd) ||
+		 uuid_le_cmp(rcd.hdr.creator_id, CPER_CREATOR_MCE))
+		goto retry;
+	memcpy(m, &rcd.mce, sizeof(*m));
+	rc = sizeof(*m);
+out:
+	erst_get_record_id_end();
+
+	return rc;
+}
+
+/* Check whether there is record in ERST */
+int apei_check_mce(void)
+{
+	return erst_get_record_count();
+}
+
+int apei_clear_mce(u64 record_id)
+{
+	return erst_clear(record_id);
+}

arch/x86/kernel/cpu/mcheck/mce-inject.c

@@ -0,0 +1,256 @@
+/*
+ * Machine check injection support.
+ * Copyright 2008 Intel Corporation.
+ *
+ * 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; version 2
+ * of the License.
+ *
+ * Authors:
+ * Andi Kleen
+ * Ying Huang
+ */
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/preempt.h>
+#include <linux/smp.h>
+#include <linux/notifier.h>
+#include <linux/kdebug.h>
+#include <linux/cpu.h>
+#include <linux/sched.h>
+#include <linux/gfp.h>
+#include <asm/mce.h>
+#include <asm/apic.h>
+#include <asm/nmi.h>
+
+/* Update fake mce registers on current CPU. */
+static void inject_mce(struct mce *m)
+{
+	struct mce *i = &per_cpu(injectm, m->extcpu);
+
+	/* Make sure no one reads partially written injectm */
+	i->finished = 0;
+	mb();
+	m->finished = 0;
+	/* First set the fields after finished */
+	i->extcpu = m->extcpu;
+	mb();
+	/* Now write record in order, finished last (except above) */
+	memcpy(i, m, sizeof(struct mce));
+	/* Finally activate it */
+	mb();
+	i->finished = 1;
+}
+
+static void raise_poll(struct mce *m)
+{
+	unsigned long flags;
+	mce_banks_t b;
+
+	memset(&b, 0xff, sizeof(mce_banks_t));
+	local_irq_save(flags);
+	machine_check_poll(0, &b);
+	local_irq_restore(flags);
+	m->finished = 0;
+}
+
+static void raise_exception(struct mce *m, struct pt_regs *pregs)
+{
+	struct pt_regs regs;
+	unsigned long flags;
+
+	if (!pregs) {
+		memset(&regs, 0, sizeof(struct pt_regs));
+		regs.ip = m->ip;
+		regs.cs = m->cs;
+		pregs = &regs;
+	}
+	/* in mcheck exeception handler, irq will be disabled */
+	local_irq_save(flags);
+	do_machine_check(pregs, 0);
+	local_irq_restore(flags);
+	m->finished = 0;
+}
+
+static cpumask_var_t mce_inject_cpumask;
+static DEFINE_MUTEX(mce_inject_mutex);
+
+static int mce_raise_notify(unsigned int cmd, struct pt_regs *regs)
+{
+	int cpu = smp_processor_id();
+	struct mce *m = this_cpu_ptr(&injectm);
+	if (!cpumask_test_cpu(cpu, mce_inject_cpumask))
+		return NMI_DONE;
+	cpumask_clear_cpu(cpu, mce_inject_cpumask);
+	if (m->inject_flags & MCJ_EXCEPTION)
+		raise_exception(m, regs);
+	else if (m->status)
+		raise_poll(m);
+	return NMI_HANDLED;
+}
+
+static void mce_irq_ipi(void *info)
+{
+	int cpu = smp_processor_id();
+	struct mce *m = this_cpu_ptr(&injectm);
+
+	if (cpumask_test_cpu(cpu, mce_inject_cpumask) &&
+			m->inject_flags & MCJ_EXCEPTION) {
+		cpumask_clear_cpu(cpu, mce_inject_cpumask);
+		raise_exception(m, NULL);
+	}
+}
+
+/* Inject mce on current CPU */
+static int raise_local(void)
+{
+	struct mce *m = this_cpu_ptr(&injectm);
+	int context = MCJ_CTX(m->inject_flags);
+	int ret = 0;
+	int cpu = m->extcpu;
+
+	if (m->inject_flags & MCJ_EXCEPTION) {
+		printk(KERN_INFO "Triggering MCE exception on CPU %d\n", cpu);
+		switch (context) {
+		case MCJ_CTX_IRQ:
+			/*
+			 * Could do more to fake interrupts like
+			 * calling irq_enter, but the necessary
+			 * machinery isn't exported currently.
+			 */
+			/*FALL THROUGH*/
+		case MCJ_CTX_PROCESS:
+			raise_exception(m, NULL);
+			break;
+		default:
+			printk(KERN_INFO "Invalid MCE context\n");
+			ret = -EINVAL;
+		}
+		printk(KERN_INFO "MCE exception done on CPU %d\n", cpu);
+	} else if (m->status) {
+		printk(KERN_INFO "Starting machine check poll CPU %d\n", cpu);
+		raise_poll(m);
+		mce_notify_irq();
+		printk(KERN_INFO "Machine check poll done on CPU %d\n", cpu);
+	} else
+		m->finished = 0;
+
+	return ret;
+}
+
+static void raise_mce(struct mce *m)
+{
+	int context = MCJ_CTX(m->inject_flags);
+
+	inject_mce(m);
+
+	if (context == MCJ_CTX_RANDOM)
+		return;
+
+#ifdef CONFIG_X86_LOCAL_APIC
+	if (m->inject_flags & (MCJ_IRQ_BROADCAST | MCJ_NMI_BROADCAST)) {
+		unsigned long start;
+		int cpu;
+
+		get_online_cpus();
+		cpumask_copy(mce_inject_cpumask, cpu_online_mask);
+		cpumask_clear_cpu(get_cpu(), mce_inject_cpumask);
+		for_each_online_cpu(cpu) {
+			struct mce *mcpu = &per_cpu(injectm, cpu);
+			if (!mcpu->finished ||
+			    MCJ_CTX(mcpu->inject_flags) != MCJ_CTX_RANDOM)
+				cpumask_clear_cpu(cpu, mce_inject_cpumask);
+		}
+		if (!cpumask_empty(mce_inject_cpumask)) {
+			if (m->inject_flags & MCJ_IRQ_BROADCAST) {
+				/*
+				 * don't wait because mce_irq_ipi is necessary
+				 * to be sync with following raise_local
+				 */
+				preempt_disable();
+				smp_call_function_many(mce_inject_cpumask,
+					mce_irq_ipi, NULL, 0);
+				preempt_enable();
+			} else if (m->inject_flags & MCJ_NMI_BROADCAST)
+				apic->send_IPI_mask(mce_inject_cpumask,
+						NMI_VECTOR);
+		}
+		start = jiffies;
+		while (!cpumask_empty(mce_inject_cpumask)) {
+			if (!time_before(jiffies, start + 2*HZ)) {
+				printk(KERN_ERR
+				"Timeout waiting for mce inject %lx\n",
+					*cpumask_bits(mce_inject_cpumask));
+				break;
+			}
+			cpu_relax();
+		}
+		raise_local();
+		put_cpu();
+		put_online_cpus();
+	} else
+#endif
+	{
+		preempt_disable();
+		raise_local();
+		preempt_enable();
+	}
+}
+
+/* Error injection interface */
+static ssize_t mce_write(struct file *filp, const char __user *ubuf,
+			 size_t usize, loff_t *off)
+{
+	struct mce m;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	/*
+	 * There are some cases where real MSR reads could slip
+	 * through.
+	 */
+	if (!boot_cpu_has(X86_FEATURE_MCE) || !boot_cpu_has(X86_FEATURE_MCA))
+		return -EIO;
+
+	if ((unsigned long)usize > sizeof(struct mce))
+		usize = sizeof(struct mce);
+	if (copy_from_user(&m, ubuf, usize))
+		return -EFAULT;
+
+	if (m.extcpu >= num_possible_cpus() || !cpu_online(m.extcpu))
+		return -EINVAL;
+
+	/*
+	 * Need to give user space some time to set everything up,
+	 * so do it a jiffie or two later everywhere.
+	 */
+	schedule_timeout(2);
+
+	mutex_lock(&mce_inject_mutex);
+	raise_mce(&m);
+	mutex_unlock(&mce_inject_mutex);
+	return usize;
+}
+
+static int inject_init(void)
+{
+	if (!alloc_cpumask_var(&mce_inject_cpumask, GFP_KERNEL))
+		return -ENOMEM;
+	printk(KERN_INFO "Machine check injector initialized\n");
+	register_mce_write_callback(mce_write);
+	register_nmi_handler(NMI_LOCAL, mce_raise_notify, 0,
+				"mce_notify");
+	return 0;
+}
+
+module_init(inject_init);
+/*
+ * Cannot tolerate unloading currently because we cannot
+ * guarantee all openers of mce_chrdev will get a reference to us.
+ */
+MODULE_LICENSE("GPL");

arch/x86/kernel/cpu/mcheck/mce-internal.h

@@ -0,0 +1,66 @@
+#include <linux/device.h>
+#include <asm/mce.h>
+
+enum severity_level {
+	MCE_NO_SEVERITY,
+	MCE_KEEP_SEVERITY,
+	MCE_SOME_SEVERITY,
+	MCE_AO_SEVERITY,
+	MCE_UC_SEVERITY,
+	MCE_AR_SEVERITY,
+	MCE_PANIC_SEVERITY,
+};
+
+#define ATTR_LEN		16
+
+/* One object for each MCE bank, shared by all CPUs */
+struct mce_bank {
+	u64			ctl;			/* subevents to enable */
+	unsigned char init;				/* initialise bank? */
+	struct device_attribute attr;			/* device attribute */
+	char			attrname[ATTR_LEN];	/* attribute name */
+};
+
+int mce_severity(struct mce *a, int tolerant, char **msg);
+struct dentry *mce_get_debugfs_dir(void);
+
+extern struct mce_bank *mce_banks;
+extern mce_banks_t mce_banks_ce_disabled;
+
+#ifdef CONFIG_X86_MCE_INTEL
+unsigned long mce_intel_adjust_timer(unsigned long interval);
+void mce_intel_cmci_poll(void);
+void mce_intel_hcpu_update(unsigned long cpu);
+void cmci_disable_bank(int bank);
+#else
+# define mce_intel_adjust_timer mce_adjust_timer_default
+static inline void mce_intel_cmci_poll(void) { }
+static inline void mce_intel_hcpu_update(unsigned long cpu) { }
+static inline void cmci_disable_bank(int bank) { }
+#endif
+
+void mce_timer_kick(unsigned long interval);
+
+#ifdef CONFIG_ACPI_APEI
+int apei_write_mce(struct mce *m);
+ssize_t apei_read_mce(struct mce *m, u64 *record_id);
+int apei_check_mce(void);
+int apei_clear_mce(u64 record_id);
+#else
+static inline int apei_write_mce(struct mce *m)
+{
+	return -EINVAL;
+}
+static inline ssize_t apei_read_mce(struct mce *m, u64 *record_id)
+{
+	return 0;
+}
+static inline int apei_check_mce(void)
+{
+	return 0;
+}
+static inline int apei_clear_mce(u64 record_id)
+{
+	return -EINVAL;
+}
+#endif

arch/x86/kernel/cpu/mcheck/mce-severity.c

@@ -0,0 +1,283 @@
+/*
+ * MCE grading rules.
+ * Copyright 2008, 2009 Intel Corporation.
+ *
+ * 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; version 2
+ * of the License.
+ *
+ * Author: Andi Kleen
+ */
+#include <linux/kernel.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/debugfs.h>
+#include <asm/mce.h>
+
+#include "mce-internal.h"
+
+/*
+ * Grade an mce by severity. In general the most severe ones are processed
+ * first. Since there are quite a lot of combinations test the bits in a
+ * table-driven way. The rules are simply processed in order, first
+ * match wins.
+ *
+ * Note this is only used for machine check exceptions, the corrected
+ * errors use much simpler rules. The exceptions still check for the corrected
+ * errors, but only to leave them alone for the CMCI handler (except for
+ * panic situations)
+ */
+
+enum context { IN_KERNEL = 1, IN_USER = 2 };
+enum ser { SER_REQUIRED = 1, NO_SER = 2 };
+
+static struct severity {
+	u64 mask;
+	u64 result;
+	unsigned char sev;
+	unsigned char mcgmask;
+	unsigned char mcgres;
+	unsigned char ser;
+	unsigned char context;
+	unsigned char covered;
+	char *msg;
+} severities[] = {
+#define MCESEV(s, m, c...) { .sev = MCE_ ## s ## _SEVERITY, .msg = m, ## c }
+#define  KERNEL		.context = IN_KERNEL
+#define  USER		.context = IN_USER
+#define  SER		.ser = SER_REQUIRED
+#define  NOSER		.ser = NO_SER
+#define  BITCLR(x)	.mask = x, .result = 0
+#define  BITSET(x)	.mask = x, .result = x
+#define  MCGMASK(x, y)	.mcgmask = x, .mcgres = y
+#define  MASK(x, y)	.mask = x, .result = y
+#define MCI_UC_S (MCI_STATUS_UC|MCI_STATUS_S)
+#define MCI_UC_SAR (MCI_STATUS_UC|MCI_STATUS_S|MCI_STATUS_AR)
+#define	MCI_ADDR (MCI_STATUS_ADDRV|MCI_STATUS_MISCV)
+
+	MCESEV(
+		NO, "Invalid",
+		BITCLR(MCI_STATUS_VAL)
+		),
+	MCESEV(
+		NO, "Not enabled",
+		BITCLR(MCI_STATUS_EN)
+		),
+	MCESEV(
+		PANIC, "Processor context corrupt",
+		BITSET(MCI_STATUS_PCC)
+		),
+	/* When MCIP is not set something is very confused */
+	MCESEV(
+		PANIC, "MCIP not set in MCA handler",
+		MCGMASK(MCG_STATUS_MCIP, 0)
+		),
+	/* Neither return not error IP -- no chance to recover -> PANIC */
+	MCESEV(
+		PANIC, "Neither restart nor error IP",
+		MCGMASK(MCG_STATUS_RIPV|MCG_STATUS_EIPV, 0)
+		),
+	MCESEV(
+		PANIC, "In kernel and no restart IP",
+		KERNEL, MCGMASK(MCG_STATUS_RIPV, 0)
+		),
+	MCESEV(
+		KEEP, "Corrected error",
+		NOSER, BITCLR(MCI_STATUS_UC)
+		),
+
+	/* ignore OVER for UCNA */
+	MCESEV(
+		KEEP, "Uncorrected no action required",
+		SER, MASK(MCI_UC_SAR, MCI_STATUS_UC)
+		),
+	MCESEV(
+		PANIC, "Illegal combination (UCNA with AR=1)",
+		SER,
+		MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_UC|MCI_STATUS_AR)
+		),
+	MCESEV(
+		KEEP, "Non signalled machine check",
+		SER, BITCLR(MCI_STATUS_S)
+		),
+
+	MCESEV(
+		PANIC, "Action required with lost events",
+		SER, BITSET(MCI_STATUS_OVER|MCI_UC_SAR)
+		),
+
+	/* known AR MCACODs: */
+#ifdef	CONFIG_MEMORY_FAILURE
+	MCESEV(
+		KEEP, "Action required but unaffected thread is continuable",
+		SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCI_ADDR, MCI_UC_SAR|MCI_ADDR),
+		MCGMASK(MCG_STATUS_RIPV|MCG_STATUS_EIPV, MCG_STATUS_RIPV)
+		),
+	MCESEV(
+		AR, "Action required: data load error in a user process",
+		SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCI_ADDR|MCACOD, MCI_UC_SAR|MCI_ADDR|MCACOD_DATA),
+		USER
+		),
+	MCESEV(
+		AR, "Action required: instruction fetch error in a user process",
+		SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCI_ADDR|MCACOD, MCI_UC_SAR|MCI_ADDR|MCACOD_INSTR),
+		USER
+		),
+#endif
+	MCESEV(
+		PANIC, "Action required: unknown MCACOD",
+		SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_SAR)
+		),
+
+	/* known AO MCACODs: */
+	MCESEV(
+		AO, "Action optional: memory scrubbing error",
+		SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCACOD_SCRUBMSK, MCI_UC_S|MCACOD_SCRUB)
+		),
+	MCESEV(
+		AO, "Action optional: last level cache writeback error",
+		SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCACOD, MCI_UC_S|MCACOD_L3WB)
+		),
+	MCESEV(
+		SOME, "Action optional: unknown MCACOD",
+		SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_S)
+		),
+	MCESEV(
+		SOME, "Action optional with lost events",
+		SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_OVER|MCI_UC_S)
+		),
+
+	MCESEV(
+		PANIC, "Overflowed uncorrected",
+		BITSET(MCI_STATUS_OVER|MCI_STATUS_UC)
+		),
+	MCESEV(
+		UC, "Uncorrected",
+		BITSET(MCI_STATUS_UC)
+		),
+	MCESEV(
+		SOME, "No match",
+		BITSET(0)
+		)	/* always matches. keep at end */
+};
+
+/*
+ * If mcgstatus indicated that ip/cs on the stack were
+ * no good, then "m->cs" will be zero and we will have
+ * to assume the worst case (IN_KERNEL) as we actually
+ * have no idea what we were executing when the machine
+ * check hit.
+ * If we do have a good "m->cs" (or a faked one in the
+ * case we were executing in VM86 mode) we can use it to
+ * distinguish an exception taken in user from from one
+ * taken in the kernel.
+ */
+static int error_context(struct mce *m)
+{
+	return ((m->cs & 3) == 3) ? IN_USER : IN_KERNEL;
+}
+
+int mce_severity(struct mce *m, int tolerant, char **msg)
+{
+	enum context ctx = error_context(m);
+	struct severity *s;
+
+	for (s = severities;; s++) {
+		if ((m->status & s->mask) != s->result)
+			continue;
+		if ((m->mcgstatus & s->mcgmask) != s->mcgres)
+			continue;
+		if (s->ser == SER_REQUIRED && !mca_cfg.ser)
+			continue;
+		if (s->ser == NO_SER && mca_cfg.ser)
+			continue;
+		if (s->context && ctx != s->context)
+			continue;
+		if (msg)
+			*msg = s->msg;
+		s->covered = 1;
+		if (s->sev >= MCE_UC_SEVERITY && ctx == IN_KERNEL) {
+			if (panic_on_oops || tolerant < 1)
+				return MCE_PANIC_SEVERITY;
+		}
+		return s->sev;
+	}
+}
+
+#ifdef CONFIG_DEBUG_FS
+static void *s_start(struct seq_file *f, loff_t *pos)
+{
+	if (*pos >= ARRAY_SIZE(severities))
+		return NULL;
+	return &severities[*pos];
+}
+
+static void *s_next(struct seq_file *f, void *data, loff_t *pos)
+{
+	if (++(*pos) >= ARRAY_SIZE(severities))
+		return NULL;
+	return &severities[*pos];
+}
+
+static void s_stop(struct seq_file *f, void *data)
+{
+}
+
+static int s_show(struct seq_file *f, void *data)
+{
+	struct severity *ser = data;
+	seq_printf(f, "%d\t%s\n", ser->covered, ser->msg);
+	return 0;
+}
+
+static const struct seq_operations severities_seq_ops = {
+	.start	= s_start,
+	.next	= s_next,
+	.stop	= s_stop,
+	.show	= s_show,
+};
+
+static int severities_coverage_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &severities_seq_ops);
+}
+
+static ssize_t severities_coverage_write(struct file *file,
+					 const char __user *ubuf,
+					 size_t count, loff_t *ppos)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(severities); i++)
+		severities[i].covered = 0;
+	return count;
+}
+
+static const struct file_operations severities_coverage_fops = {
+	.open		= severities_coverage_open,
+	.release	= seq_release,
+	.read		= seq_read,
+	.write		= severities_coverage_write,
+	.llseek		= seq_lseek,
+};
+
+static int __init severities_debugfs_init(void)
+{
+	struct dentry *dmce, *fsev;
+
+	dmce = mce_get_debugfs_dir();
+	if (!dmce)
+		goto err_out;
+
+	fsev = debugfs_create_file("severities-coverage", 0444, dmce, NULL,
+				   &severities_coverage_fops);
+	if (!fsev)
+		goto err_out;
+
+	return 0;
+
+err_out:
+	return -ENOMEM;
+}
+late_initcall(severities_debugfs_init);
+#endif /* CONFIG_DEBUG_FS */

arch/x86/kernel/cpu/mcheck/mce_amd.c

@@ -0,0 +1,789 @@
+/*
+ *  (c) 2005-2012 Advanced Micro Devices, Inc.
+ *  Your use of this code is subject to the terms and conditions of the
+ *  GNU general public license version 2. See "COPYING" or
+ *  http://www.gnu.org/licenses/gpl.html
+ *
+ *  Written by Jacob Shin - AMD, Inc.
+ *
+ *  Maintained by: Borislav Petkov <bp@alien8.de>
+ *
+ *  April 2006
+ *     - added support for AMD Family 0x10 processors
+ *  May 2012
+ *     - major scrubbing
+ *
+ *  All MC4_MISCi registers are shared between multi-cores
+ */
+#include <linux/interrupt.h>
+#include <linux/notifier.h>
+#include <linux/kobject.h>
+#include <linux/percpu.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+
+#include <asm/amd_nb.h>
+#include <asm/apic.h>
+#include <asm/idle.h>
+#include <asm/mce.h>
+#include <asm/msr.h>
+
+#define NR_BLOCKS         9
+#define THRESHOLD_MAX     0xFFF
+#define INT_TYPE_APIC     0x00020000
+#define MASK_VALID_HI     0x80000000
+#define MASK_CNTP_HI      0x40000000
+#define MASK_LOCKED_HI    0x20000000
+#define MASK_LVTOFF_HI    0x00F00000
+#define MASK_COUNT_EN_HI  0x00080000
+#define MASK_INT_TYPE_HI  0x00060000
+#define MASK_OVERFLOW_HI  0x00010000
+#define MASK_ERR_COUNT_HI 0x00000FFF
+#define MASK_BLKPTR_LO    0xFF000000
+#define MCG_XBLK_ADDR     0xC0000400
+
+static const char * const th_names[] = {
+	"load_store",
+	"insn_fetch",
+	"combined_unit",
+	"",
+	"northbridge",
+	"execution_unit",
+};
+
+static DEFINE_PER_CPU(struct threshold_bank **, threshold_banks);
+static DEFINE_PER_CPU(unsigned char, bank_map);	/* see which banks are on */
+
+static void amd_threshold_interrupt(void);
+
+/*
+ * CPU Initialization
+ */
+
+struct thresh_restart {
+	struct threshold_block	*b;
+	int			reset;
+	int			set_lvt_off;
+	int			lvt_off;
+	u16			old_limit;
+};
+
+static inline bool is_shared_bank(int bank)
+{
+	/* Bank 4 is for northbridge reporting and is thus shared */
+	return (bank == 4);
+}
+
+static const char * const bank4_names(struct threshold_block *b)
+{
+	switch (b->address) {
+	/* MSR4_MISC0 */
+	case 0x00000413:
+		return "dram";
+
+	case 0xc0000408:
+		return "ht_links";
+
+	case 0xc0000409:
+		return "l3_cache";
+
+	default:
+		WARN(1, "Funny MSR: 0x%08x\n", b->address);
+		return "";
+	}
+};
+
+
+static bool lvt_interrupt_supported(unsigned int bank, u32 msr_high_bits)
+{
+	/*
+	 * bank 4 supports APIC LVT interrupts implicitly since forever.
+	 */
+	if (bank == 4)
+		return true;
+
+	/*
+	 * IntP: interrupt present; if this bit is set, the thresholding
+	 * bank can generate APIC LVT interrupts
+	 */
+	return msr_high_bits & BIT(28);
+}
+
+static int lvt_off_valid(struct threshold_block *b, int apic, u32 lo, u32 hi)
+{
+	int msr = (hi & MASK_LVTOFF_HI) >> 20;
+
+	if (apic < 0) {
+		pr_err(FW_BUG "cpu %d, failed to setup threshold interrupt "
+		       "for bank %d, block %d (MSR%08X=0x%x%08x)\n", b->cpu,
+		       b->bank, b->block, b->address, hi, lo);
+		return 0;
+	}
+
+	if (apic != msr) {
+		pr_err(FW_BUG "cpu %d, invalid threshold interrupt offset %d "
+		       "for bank %d, block %d (MSR%08X=0x%x%08x)\n",
+		       b->cpu, apic, b->bank, b->block, b->address, hi, lo);
+		return 0;
+	}
+
+	return 1;
+};
+
+/*
+ * Called via smp_call_function_single(), must be called with correct
+ * cpu affinity.
+ */
+static void threshold_restart_bank(void *_tr)
+{
+	struct thresh_restart *tr = _tr;
+	u32 hi, lo;
+
+	rdmsr(tr->b->address, lo, hi);
+
+	if (tr->b->threshold_limit < (hi & THRESHOLD_MAX))
+		tr->reset = 1;	/* limit cannot be lower than err count */
+
+	if (tr->reset) {		/* reset err count and overflow bit */
+		hi =
+		    (hi & ~(MASK_ERR_COUNT_HI | MASK_OVERFLOW_HI)) |
+		    (THRESHOLD_MAX - tr->b->threshold_limit);
+	} else if (tr->old_limit) {	/* change limit w/o reset */
+		int new_count = (hi & THRESHOLD_MAX) +
+		    (tr->old_limit - tr->b->threshold_limit);
+
+		hi = (hi & ~MASK_ERR_COUNT_HI) |
+		    (new_count & THRESHOLD_MAX);
+	}
+
+	/* clear IntType */
+	hi &= ~MASK_INT_TYPE_HI;
+
+	if (!tr->b->interrupt_capable)
+		goto done;
+
+	if (tr->set_lvt_off) {
+		if (lvt_off_valid(tr->b, tr->lvt_off, lo, hi)) {
+			/* set new lvt offset */
+			hi &= ~MASK_LVTOFF_HI;
+			hi |= tr->lvt_off << 20;
+		}
+	}
+
+	if (tr->b->interrupt_enable)
+		hi |= INT_TYPE_APIC;
+
+ done:
+
+	hi |= MASK_COUNT_EN_HI;
+	wrmsr(tr->b->address, lo, hi);
+}
+
+static void mce_threshold_block_init(struct threshold_block *b, int offset)
+{
+	struct thresh_restart tr = {
+		.b			= b,
+		.set_lvt_off		= 1,
+		.lvt_off		= offset,
+	};
+
+	b->threshold_limit		= THRESHOLD_MAX;
+	threshold_restart_bank(&tr);
+};
+
+static int setup_APIC_mce(int reserved, int new)
+{
+	if (reserved < 0 && !setup_APIC_eilvt(new, THRESHOLD_APIC_VECTOR,
+					      APIC_EILVT_MSG_FIX, 0))
+		return new;
+
+	return reserved;
+}
+
+/* cpu init entry point, called from mce.c with preempt off */
+void mce_amd_feature_init(struct cpuinfo_x86 *c)
+{
+	struct threshold_block b;
+	unsigned int cpu = smp_processor_id();
+	u32 low = 0, high = 0, address = 0;
+	unsigned int bank, block;
+	int offset = -1;
+
+	for (bank = 0; bank < mca_cfg.banks; ++bank) {
+		for (block = 0; block < NR_BLOCKS; ++block) {
+			if (block == 0)
+				address = MSR_IA32_MC0_MISC + bank * 4;
+			else if (block == 1) {
+				address = (low & MASK_BLKPTR_LO) >> 21;
+				if (!address)
+					break;
+
+				address += MCG_XBLK_ADDR;
+			} else
+				++address;
+
+			if (rdmsr_safe(address, &low, &high))
+				break;
+
+			if (!(high & MASK_VALID_HI))
+				continue;
+
+			if (!(high & MASK_CNTP_HI)  ||
+			     (high & MASK_LOCKED_HI))
+				continue;
+
+			if (!block)
+				per_cpu(bank_map, cpu) |= (1 << bank);
+
+			memset(&b, 0, sizeof(b));
+			b.cpu			= cpu;
+			b.bank			= bank;
+			b.block			= block;
+			b.address		= address;
+			b.interrupt_capable	= lvt_interrupt_supported(bank, high);
+
+			if (b.interrupt_capable) {
+				int new = (high & MASK_LVTOFF_HI) >> 20;
+				offset  = setup_APIC_mce(offset, new);
+			}
+
+			mce_threshold_block_init(&b, offset);
+			mce_threshold_vector = amd_threshold_interrupt;
+		}
+	}
+}
+
+/*
+ * APIC Interrupt Handler
+ */
+
+/*
+ * threshold interrupt handler will service THRESHOLD_APIC_VECTOR.
+ * the interrupt goes off when error_count reaches threshold_limit.
+ * the handler will simply log mcelog w/ software defined bank number.
+ */
+static void amd_threshold_interrupt(void)
+{
+	u32 low = 0, high = 0, address = 0;
+	unsigned int bank, block;
+	struct mce m;
+
+	mce_setup(&m);
+
+	/* assume first bank caused it */
+	for (bank = 0; bank < mca_cfg.banks; ++bank) {
+		if (!(per_cpu(bank_map, m.cpu) & (1 << bank)))
+			continue;
+		for (block = 0; block < NR_BLOCKS; ++block) {
+			if (block == 0) {
+				address = MSR_IA32_MC0_MISC + bank * 4;
+			} else if (block == 1) {
+				address = (low & MASK_BLKPTR_LO) >> 21;
+				if (!address)
+					break;
+				address += MCG_XBLK_ADDR;
+			} else {
+				++address;
+			}
+
+			if (rdmsr_safe(address, &low, &high))
+				break;
+
+			if (!(high & MASK_VALID_HI)) {
+				if (block)
+					continue;
+				else
+					break;
+			}
+
+			if (!(high & MASK_CNTP_HI)  ||
+			     (high & MASK_LOCKED_HI))
+				continue;
+
+			/*
+			 * Log the machine check that caused the threshold
+			 * event.
+			 */
+			machine_check_poll(MCP_TIMESTAMP,
+					this_cpu_ptr(&mce_poll_banks));
+
+			if (high & MASK_OVERFLOW_HI) {
+				rdmsrl(address, m.misc);
+				rdmsrl(MSR_IA32_MC0_STATUS + bank * 4,
+				       m.status);
+				m.bank = K8_MCE_THRESHOLD_BASE
+				       + bank * NR_BLOCKS
+				       + block;
+				mce_log(&m);
+				return;
+			}
+		}
+	}
+}
+
+/*
+ * Sysfs Interface
+ */
+
+struct threshold_attr {
+	struct attribute attr;
+	ssize_t (*show) (struct threshold_block *, char *);
+	ssize_t (*store) (struct threshold_block *, const char *, size_t count);
+};
+
+#define SHOW_FIELDS(name)						\
+static ssize_t show_ ## name(struct threshold_block *b, char *buf)	\
+{									\
+	return sprintf(buf, "%lu\n", (unsigned long) b->name);		\
+}
+SHOW_FIELDS(interrupt_enable)
+SHOW_FIELDS(threshold_limit)
+
+static ssize_t
+store_interrupt_enable(struct threshold_block *b, const char *buf, size_t size)
+{
+	struct thresh_restart tr;
+	unsigned long new;
+
+	if (!b->interrupt_capable)
+		return -EINVAL;
+
+	if (kstrtoul(buf, 0, &new) < 0)
+		return -EINVAL;
+
+	b->interrupt_enable = !!new;
+
+	memset(&tr, 0, sizeof(tr));
+	tr.b		= b;
+
+	smp_call_function_single(b->cpu, threshold_restart_bank, &tr, 1);
+
+	return size;
+}
+
+static ssize_t
+store_threshold_limit(struct threshold_block *b, const char *buf, size_t size)
+{
+	struct thresh_restart tr;
+	unsigned long new;
+
+	if (kstrtoul(buf, 0, &new) < 0)
+		return -EINVAL;
+
+	if (new > THRESHOLD_MAX)
+		new = THRESHOLD_MAX;
+	if (new < 1)
+		new = 1;
+
+	memset(&tr, 0, sizeof(tr));
+	tr.old_limit = b->threshold_limit;
+	b->threshold_limit = new;
+	tr.b = b;
+
+	smp_call_function_single(b->cpu, threshold_restart_bank, &tr, 1);
+
+	return size;
+}
+
+static ssize_t show_error_count(struct threshold_block *b, char *buf)
+{
+	u32 lo, hi;
+
+	rdmsr_on_cpu(b->cpu, b->address, &lo, &hi);
+
+	return sprintf(buf, "%u\n", ((hi & THRESHOLD_MAX) -
+				     (THRESHOLD_MAX - b->threshold_limit)));
+}
+
+static struct threshold_attr error_count = {
+	.attr = {.name = __stringify(error_count), .mode = 0444 },
+	.show = show_error_count,
+};
+
+#define RW_ATTR(val)							\
+static struct threshold_attr val = {					\
+	.attr	= {.name = __stringify(val), .mode = 0644 },		\
+	.show	= show_## val,						\
+	.store	= store_## val,						\
+};
+
+RW_ATTR(interrupt_enable);
+RW_ATTR(threshold_limit);
+
+static struct attribute *default_attrs[] = {
+	&threshold_limit.attr,
+	&error_count.attr,
+	NULL,	/* possibly interrupt_enable if supported, see below */
+	NULL,
+};
+
+#define to_block(k)	container_of(k, struct threshold_block, kobj)
+#define to_attr(a)	container_of(a, struct threshold_attr, attr)
+
+static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
+{
+	struct threshold_block *b = to_block(kobj);
+	struct threshold_attr *a = to_attr(attr);
+	ssize_t ret;
+
+	ret = a->show ? a->show(b, buf) : -EIO;
+
+	return ret;
+}
+
+static ssize_t store(struct kobject *kobj, struct attribute *attr,
+		     const char *buf, size_t count)
+{
+	struct threshold_block *b = to_block(kobj);
+	struct threshold_attr *a = to_attr(attr);
+	ssize_t ret;
+
+	ret = a->store ? a->store(b, buf, count) : -EIO;
+
+	return ret;
+}
+
+static const struct sysfs_ops threshold_ops = {
+	.show			= show,
+	.store			= store,
+};
+
+static struct kobj_type threshold_ktype = {
+	.sysfs_ops		= &threshold_ops,
+	.default_attrs		= default_attrs,
+};
+
+static int allocate_threshold_blocks(unsigned int cpu, unsigned int bank,
+				     unsigned int block, u32 address)
+{
+	struct threshold_block *b = NULL;
+	u32 low, high;
+	int err;
+
+	if ((bank >= mca_cfg.banks) || (block >= NR_BLOCKS))
+		return 0;
+
+	if (rdmsr_safe_on_cpu(cpu, address, &low, &high))
+		return 0;
+
+	if (!(high & MASK_VALID_HI)) {
+		if (block)
+			goto recurse;
+		else
+			return 0;
+	}
+
+	if (!(high & MASK_CNTP_HI)  ||
+	     (high & MASK_LOCKED_HI))
+		goto recurse;
+
+	b = kzalloc(sizeof(struct threshold_block), GFP_KERNEL);
+	if (!b)
+		return -ENOMEM;
+
+	b->block		= block;
+	b->bank			= bank;
+	b->cpu			= cpu;
+	b->address		= address;
+	b->interrupt_enable	= 0;
+	b->interrupt_capable	= lvt_interrupt_supported(bank, high);
+	b->threshold_limit	= THRESHOLD_MAX;
+
+	if (b->interrupt_capable)
+		threshold_ktype.default_attrs[2] = &interrupt_enable.attr;
+	else
+		threshold_ktype.default_attrs[2] = NULL;
+
+	INIT_LIST_HEAD(&b->miscj);
+
+	if (per_cpu(threshold_banks, cpu)[bank]->blocks) {
+		list_add(&b->miscj,
+			 &per_cpu(threshold_banks, cpu)[bank]->blocks->miscj);
+	} else {
+		per_cpu(threshold_banks, cpu)[bank]->blocks = b;
+	}
+
+	err = kobject_init_and_add(&b->kobj, &threshold_ktype,
+				   per_cpu(threshold_banks, cpu)[bank]->kobj,
+				   (bank == 4 ? bank4_names(b) : th_names[bank]));
+	if (err)
+		goto out_free;
+recurse:
+	if (!block) {
+		address = (low & MASK_BLKPTR_LO) >> 21;
+		if (!address)
+			return 0;
+		address += MCG_XBLK_ADDR;
+	} else {
+		++address;
+	}
+
+	err = allocate_threshold_blocks(cpu, bank, ++block, address);
+	if (err)
+		goto out_free;
+
+	if (b)
+		kobject_uevent(&b->kobj, KOBJ_ADD);
+
+	return err;
+
+out_free:
+	if (b) {
+		kobject_put(&b->kobj);
+		list_del(&b->miscj);
+		kfree(b);
+	}
+	return err;
+}
+
+static int __threshold_add_blocks(struct threshold_bank *b)
+{
+	struct list_head *head = &b->blocks->miscj;
+	struct threshold_block *pos = NULL;
+	struct threshold_block *tmp = NULL;
+	int err = 0;
+
+	err = kobject_add(&b->blocks->kobj, b->kobj, b->blocks->kobj.name);
+	if (err)
+		return err;
+
+	list_for_each_entry_safe(pos, tmp, head, miscj) {
+
+		err = kobject_add(&pos->kobj, b->kobj, pos->kobj.name);
+		if (err) {
+			list_for_each_entry_safe_reverse(pos, tmp, head, miscj)
+				kobject_del(&pos->kobj);
+
+			return err;
+		}
+	}
+	return err;
+}
+
+static int threshold_create_bank(unsigned int cpu, unsigned int bank)
+{
+	struct device *dev = per_cpu(mce_device, cpu);
+	struct amd_northbridge *nb = NULL;
+	struct threshold_bank *b = NULL;
+	const char *name = th_names[bank];
+	int err = 0;
+
+	if (is_shared_bank(bank)) {
+		nb = node_to_amd_nb(amd_get_nb_id(cpu));
+
+		/* threshold descriptor already initialized on this node? */
+		if (nb && nb->bank4) {
+			/* yes, use it */
+			b = nb->bank4;
+			err = kobject_add(b->kobj, &dev->kobj, name);
+			if (err)
+				goto out;
+
+			per_cpu(threshold_banks, cpu)[bank] = b;
+			atomic_inc(&b->cpus);
+
+			err = __threshold_add_blocks(b);
+
+			goto out;
+		}
+	}
+
+	b = kzalloc(sizeof(struct threshold_bank), GFP_KERNEL);
+	if (!b) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	b->kobj = kobject_create_and_add(name, &dev->kobj);
+	if (!b->kobj) {
+		err = -EINVAL;
+		goto out_free;
+	}
+
+	per_cpu(threshold_banks, cpu)[bank] = b;
+
+	if (is_shared_bank(bank)) {
+		atomic_set(&b->cpus, 1);
+
+		/* nb is already initialized, see above */
+		if (nb) {
+			WARN_ON(nb->bank4);
+			nb->bank4 = b;
+		}
+	}
+
+	err = allocate_threshold_blocks(cpu, bank, 0,
+					MSR_IA32_MC0_MISC + bank * 4);
+	if (!err)
+		goto out;
+
+ out_free:
+	kfree(b);
+
+ out:
+	return err;
+}
+
+/* create dir/files for all valid threshold banks */
+static int threshold_create_device(unsigned int cpu)
+{
+	unsigned int bank;
+	struct threshold_bank **bp;
+	int err = 0;
+
+	bp = kzalloc(sizeof(struct threshold_bank *) * mca_cfg.banks,
+		     GFP_KERNEL);
+	if (!bp)
+		return -ENOMEM;
+
+	per_cpu(threshold_banks, cpu) = bp;
+
+	for (bank = 0; bank < mca_cfg.banks; ++bank) {
+		if (!(per_cpu(bank_map, cpu) & (1 << bank)))
+			continue;
+		err = threshold_create_bank(cpu, bank);
+		if (err)
+			return err;
+	}
+
+	return err;
+}
+
+static void deallocate_threshold_block(unsigned int cpu,
+						 unsigned int bank)
+{
+	struct threshold_block *pos = NULL;
+	struct threshold_block *tmp = NULL;
+	struct threshold_bank *head = per_cpu(threshold_banks, cpu)[bank];
+
+	if (!head)
+		return;
+
+	list_for_each_entry_safe(pos, tmp, &head->blocks->miscj, miscj) {
+		kobject_put(&pos->kobj);
+		list_del(&pos->miscj);
+		kfree(pos);
+	}
+
+	kfree(per_cpu(threshold_banks, cpu)[bank]->blocks);
+	per_cpu(threshold_banks, cpu)[bank]->blocks = NULL;
+}
+
+static void __threshold_remove_blocks(struct threshold_bank *b)
+{
+	struct threshold_block *pos = NULL;
+	struct threshold_block *tmp = NULL;
+
+	kobject_del(b->kobj);
+
+	list_for_each_entry_safe(pos, tmp, &b->blocks->miscj, miscj)
+		kobject_del(&pos->kobj);
+}
+
+static void threshold_remove_bank(unsigned int cpu, int bank)
+{
+	struct amd_northbridge *nb;
+	struct threshold_bank *b;
+
+	b = per_cpu(threshold_banks, cpu)[bank];
+	if (!b)
+		return;
+
+	if (!b->blocks)
+		goto free_out;
+
+	if (is_shared_bank(bank)) {
+		if (!atomic_dec_and_test(&b->cpus)) {
+			__threshold_remove_blocks(b);
+			per_cpu(threshold_banks, cpu)[bank] = NULL;
+			return;
+		} else {
+			/*
+			 * the last CPU on this node using the shared bank is
+			 * going away, remove that bank now.
+			 */
+			nb = node_to_amd_nb(amd_get_nb_id(cpu));
+			nb->bank4 = NULL;
+		}
+	}
+
+	deallocate_threshold_block(cpu, bank);
+
+free_out:
+	kobject_del(b->kobj);
+	kobject_put(b->kobj);
+	kfree(b);
+	per_cpu(threshold_banks, cpu)[bank] = NULL;
+}
+
+static void threshold_remove_device(unsigned int cpu)
+{
+	unsigned int bank;
+
+	for (bank = 0; bank < mca_cfg.banks; ++bank) {
+		if (!(per_cpu(bank_map, cpu) & (1 << bank)))
+			continue;
+		threshold_remove_bank(cpu, bank);
+	}
+	kfree(per_cpu(threshold_banks, cpu));
+}
+
+/* get notified when a cpu comes on/off */
+static void
+amd_64_threshold_cpu_callback(unsigned long action, unsigned int cpu)
+{
+	switch (action) {
+	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
+		threshold_create_device(cpu);
+		break;
+	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
+		threshold_remove_device(cpu);
+		break;
+	default:
+		break;
+	}
+}
+
+static __init int threshold_init_device(void)
+{
+	unsigned lcpu = 0;
+
+	/* to hit CPUs online before the notifier is up */
+	for_each_online_cpu(lcpu) {
+		int err = threshold_create_device(lcpu);
+
+		if (err)
+			return err;
+	}
+	threshold_cpu_callback = amd_64_threshold_cpu_callback;
+
+	return 0;
+}
+/*
+ * there are 3 funcs which need to be _initcalled in a logic sequence:
+ * 1. xen_late_init_mcelog
+ * 2. mcheck_init_device
+ * 3. threshold_init_device
+ *
+ * xen_late_init_mcelog must register xen_mce_chrdev_device before
+ * native mce_chrdev_device registration if running under xen platform;
+ *
+ * mcheck_init_device should be inited before threshold_init_device to
+ * initialize mce_device, otherwise a NULL ptr dereference will cause panic.
+ *
+ * so we use following _initcalls
+ * 1. device_initcall(xen_late_init_mcelog);
+ * 2. device_initcall_sync(mcheck_init_device);
+ * 3. late_initcall(threshold_init_device);
+ *
+ * when running under xen, the initcall order is 1,2,3;
+ * on baremetal, we skip 1 and we do only 2 and 3.
+ */
+late_initcall(threshold_init_device);

arch/x86/kernel/cpu/mcheck/mce_intel.c

@@ -0,0 +1,391 @@
+/*
+ * Intel specific MCE features.
+ * Copyright 2004 Zwane Mwaikambo <zwane@linuxpower.ca>
+ * Copyright (C) 2008, 2009 Intel Corporation
+ * Author: Andi Kleen
+ */
+
+#include <linux/gfp.h>
+#include <linux/interrupt.h>
+#include <linux/percpu.h>
+#include <linux/sched.h>
+#include <linux/cpumask.h>
+#include <asm/apic.h>
+#include <asm/processor.h>
+#include <asm/msr.h>
+#include <asm/mce.h>
+
+#include "mce-internal.h"
+
+/*
+ * Support for Intel Correct Machine Check Interrupts. This allows
+ * the CPU to raise an interrupt when a corrected machine check happened.
+ * Normally we pick those up using a regular polling timer.
+ * Also supports reliable discovery of shared banks.
+ */
+
+/*
+ * CMCI can be delivered to multiple cpus that share a machine check bank
+ * so we need to designate a single cpu to process errors logged in each bank
+ * in the interrupt handler (otherwise we would have many races and potential
+ * double reporting of the same error).
+ * Note that this can change when a cpu is offlined or brought online since
+ * some MCA banks are shared across cpus. When a cpu is offlined, cmci_clear()
+ * disables CMCI on all banks owned by the cpu and clears this bitfield. At
+ * this point, cmci_rediscover() kicks in and a different cpu may end up
+ * taking ownership of some of the shared MCA banks that were previously
+ * owned by the offlined cpu.
+ */
+static DEFINE_PER_CPU(mce_banks_t, mce_banks_owned);
+
+/*
+ * cmci_discover_lock protects against parallel discovery attempts
+ * which could race against each other.
+ */
+static DEFINE_RAW_SPINLOCK(cmci_discover_lock);
+
+#define CMCI_THRESHOLD		1
+#define CMCI_POLL_INTERVAL	(30 * HZ)
+#define CMCI_STORM_INTERVAL	(1 * HZ)
+#define CMCI_STORM_THRESHOLD	15
+
+static DEFINE_PER_CPU(unsigned long, cmci_time_stamp);
+static DEFINE_PER_CPU(unsigned int, cmci_storm_cnt);
+static DEFINE_PER_CPU(unsigned int, cmci_storm_state);
+
+enum {
+	CMCI_STORM_NONE,
+	CMCI_STORM_ACTIVE,
+	CMCI_STORM_SUBSIDED,
+};
+
+static atomic_t cmci_storm_on_cpus;
+
+static int cmci_supported(int *banks)
+{
+	u64 cap;
+
+	if (mca_cfg.cmci_disabled || mca_cfg.ignore_ce)
+		return 0;
+
+	/*
+	 * Vendor check is not strictly needed, but the initial
+	 * initialization is vendor keyed and this
+	 * makes sure none of the backdoors are entered otherwise.
+	 */
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+		return 0;
+	if (!cpu_has_apic || lapic_get_maxlvt() < 6)
+		return 0;
+	rdmsrl(MSR_IA32_MCG_CAP, cap);
+	*banks = min_t(unsigned, MAX_NR_BANKS, cap & 0xff);
+	return !!(cap & MCG_CMCI_P);
+}
+
+void mce_intel_cmci_poll(void)
+{
+	if (__this_cpu_read(cmci_storm_state) == CMCI_STORM_NONE)
+		return;
+	machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned));
+}
+
+void mce_intel_hcpu_update(unsigned long cpu)
+{
+	if (per_cpu(cmci_storm_state, cpu) == CMCI_STORM_ACTIVE)
+		atomic_dec(&cmci_storm_on_cpus);
+
+	per_cpu(cmci_storm_state, cpu) = CMCI_STORM_NONE;
+}
+
+unsigned long mce_intel_adjust_timer(unsigned long interval)
+{
+	int r;
+
+	if (interval < CMCI_POLL_INTERVAL)
+		return interval;
+
+	switch (__this_cpu_read(cmci_storm_state)) {
+	case CMCI_STORM_ACTIVE:
+		/*
+		 * We switch back to interrupt mode once the poll timer has
+		 * silenced itself. That means no events recorded and the
+		 * timer interval is back to our poll interval.
+		 */
+		__this_cpu_write(cmci_storm_state, CMCI_STORM_SUBSIDED);
+		r = atomic_sub_return(1, &cmci_storm_on_cpus);
+		if (r == 0)
+			pr_notice("CMCI storm subsided: switching to interrupt mode\n");
+		/* FALLTHROUGH */
+
+	case CMCI_STORM_SUBSIDED:
+		/*
+		 * We wait for all cpus to go back to SUBSIDED
+		 * state. When that happens we switch back to
+		 * interrupt mode.
+		 */
+		if (!atomic_read(&cmci_storm_on_cpus)) {
+			__this_cpu_write(cmci_storm_state, CMCI_STORM_NONE);
+			cmci_reenable();
+			cmci_recheck();
+		}
+		return CMCI_POLL_INTERVAL;
+	default:
+		/*
+		 * We have shiny weather. Let the poll do whatever it
+		 * thinks.
+		 */
+		return interval;
+	}
+}
+
+static void cmci_storm_disable_banks(void)
+{
+	unsigned long flags, *owned;
+	int bank;
+	u64 val;
+
+	raw_spin_lock_irqsave(&cmci_discover_lock, flags);
+	owned = this_cpu_ptr(mce_banks_owned);
+	for_each_set_bit(bank, owned, MAX_NR_BANKS) {
+		rdmsrl(MSR_IA32_MCx_CTL2(bank), val);
+		val &= ~MCI_CTL2_CMCI_EN;
+		wrmsrl(MSR_IA32_MCx_CTL2(bank), val);
+	}
+	raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
+}
+
+static bool cmci_storm_detect(void)
+{
+	unsigned int cnt = __this_cpu_read(cmci_storm_cnt);
+	unsigned long ts = __this_cpu_read(cmci_time_stamp);
+	unsigned long now = jiffies;
+	int r;
+
+	if (__this_cpu_read(cmci_storm_state) != CMCI_STORM_NONE)
+		return true;
+
+	if (time_before_eq(now, ts + CMCI_STORM_INTERVAL)) {
+		cnt++;
+	} else {
+		cnt = 1;
+		__this_cpu_write(cmci_time_stamp, now);
+	}
+	__this_cpu_write(cmci_storm_cnt, cnt);
+
+	if (cnt <= CMCI_STORM_THRESHOLD)
+		return false;
+
+	cmci_storm_disable_banks();
+	__this_cpu_write(cmci_storm_state, CMCI_STORM_ACTIVE);
+	r = atomic_add_return(1, &cmci_storm_on_cpus);
+	mce_timer_kick(CMCI_POLL_INTERVAL);
+
+	if (r == 1)
+		pr_notice("CMCI storm detected: switching to poll mode\n");
+	return true;
+}
+
+/*
+ * The interrupt handler. This is called on every event.
+ * Just call the poller directly to log any events.
+ * This could in theory increase the threshold under high load,
+ * but doesn't for now.
+ */
+static void intel_threshold_interrupt(void)
+{
+	if (cmci_storm_detect())
+		return;
+	machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned));
+	mce_notify_irq();
+}
+
+/*
+ * Enable CMCI (Corrected Machine Check Interrupt) for available MCE banks
+ * on this CPU. Use the algorithm recommended in the SDM to discover shared
+ * banks.
+ */
+static void cmci_discover(int banks)
+{
+	unsigned long *owned = (void *)this_cpu_ptr(&mce_banks_owned);
+	unsigned long flags;
+	int i;
+	int bios_wrong_thresh = 0;
+
+	raw_spin_lock_irqsave(&cmci_discover_lock, flags);
+	for (i = 0; i < banks; i++) {
+		u64 val;
+		int bios_zero_thresh = 0;
+
+		if (test_bit(i, owned))
+			continue;
+
+		/* Skip banks in firmware first mode */
+		if (test_bit(i, mce_banks_ce_disabled))
+			continue;
+
+		rdmsrl(MSR_IA32_MCx_CTL2(i), val);
+
+		/* Already owned by someone else? */
+		if (val & MCI_CTL2_CMCI_EN) {
+			clear_bit(i, owned);
+			__clear_bit(i, this_cpu_ptr(mce_poll_banks));
+			continue;
+		}
+
+		if (!mca_cfg.bios_cmci_threshold) {
+			val &= ~MCI_CTL2_CMCI_THRESHOLD_MASK;
+			val |= CMCI_THRESHOLD;
+		} else if (!(val & MCI_CTL2_CMCI_THRESHOLD_MASK)) {
+			/*
+			 * If bios_cmci_threshold boot option was specified
+			 * but the threshold is zero, we'll try to initialize
+			 * it to 1.
+			 */
+			bios_zero_thresh = 1;
+			val |= CMCI_THRESHOLD;
+		}
+
+		val |= MCI_CTL2_CMCI_EN;
+		wrmsrl(MSR_IA32_MCx_CTL2(i), val);
+		rdmsrl(MSR_IA32_MCx_CTL2(i), val);
+
+		/* Did the enable bit stick? -- the bank supports CMCI */
+		if (val & MCI_CTL2_CMCI_EN) {
+			set_bit(i, owned);
+			__clear_bit(i, this_cpu_ptr(mce_poll_banks));
+			/*
+			 * We are able to set thresholds for some banks that
+			 * had a threshold of 0. This means the BIOS has not
+			 * set the thresholds properly or does not work with
+			 * this boot option. Note down now and report later.
+			 */
+			if (mca_cfg.bios_cmci_threshold && bios_zero_thresh &&
+					(val & MCI_CTL2_CMCI_THRESHOLD_MASK))
+				bios_wrong_thresh = 1;
+		} else {
+			WARN_ON(!test_bit(i, this_cpu_ptr(mce_poll_banks)));
+		}
+	}
+	raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
+	if (mca_cfg.bios_cmci_threshold && bios_wrong_thresh) {
+		pr_info_once(
+			"bios_cmci_threshold: Some banks do not have valid thresholds set\n");
+		pr_info_once(
+			"bios_cmci_threshold: Make sure your BIOS supports this boot option\n");
+	}
+}
+
+/*
+ * Just in case we missed an event during initialization check
+ * all the CMCI owned banks.
+ */
+void cmci_recheck(void)
+{
+	unsigned long flags;
+	int banks;
+
+	if (!mce_available(raw_cpu_ptr(&cpu_info)) || !cmci_supported(&banks))
+		return;
+	local_irq_save(flags);
+	machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned));
+	local_irq_restore(flags);
+}
+
+/* Caller must hold the lock on cmci_discover_lock */
+static void __cmci_disable_bank(int bank)
+{
+	u64 val;
+
+	if (!test_bit(bank, this_cpu_ptr(mce_banks_owned)))
+		return;
+	rdmsrl(MSR_IA32_MCx_CTL2(bank), val);
+	val &= ~MCI_CTL2_CMCI_EN;
+	wrmsrl(MSR_IA32_MCx_CTL2(bank), val);
+	__clear_bit(bank, this_cpu_ptr(mce_banks_owned));
+}
+
+/*
+ * Disable CMCI on this CPU for all banks it owns when it goes down.
+ * This allows other CPUs to claim the banks on rediscovery.
+ */
+void cmci_clear(void)
+{
+	unsigned long flags;
+	int i;
+	int banks;
+
+	if (!cmci_supported(&banks))
+		return;
+	raw_spin_lock_irqsave(&cmci_discover_lock, flags);
+	for (i = 0; i < banks; i++)
+		__cmci_disable_bank(i);
+	raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
+}
+
+static void cmci_rediscover_work_func(void *arg)
+{
+	int banks;
+
+	/* Recheck banks in case CPUs don't all have the same */
+	if (cmci_supported(&banks))
+		cmci_discover(banks);
+}
+
+/* After a CPU went down cycle through all the others and rediscover */
+void cmci_rediscover(void)
+{
+	int banks;
+
+	if (!cmci_supported(&banks))
+		return;
+
+	on_each_cpu(cmci_rediscover_work_func, NULL, 1);
+}
+
+/*
+ * Reenable CMCI on this CPU in case a CPU down failed.
+ */
+void cmci_reenable(void)
+{
+	int banks;
+	if (cmci_supported(&banks))
+		cmci_discover(banks);
+}
+
+void cmci_disable_bank(int bank)
+{
+	int banks;
+	unsigned long flags;
+
+	if (!cmci_supported(&banks))
+		return;
+
+	raw_spin_lock_irqsave(&cmci_discover_lock, flags);
+	__cmci_disable_bank(bank);
+	raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
+}
+
+static void intel_init_cmci(void)
+{
+	int banks;
+
+	if (!cmci_supported(&banks))
+		return;
+
+	mce_threshold_vector = intel_threshold_interrupt;
+	cmci_discover(banks);
+	/*
+	 * For CPU #0 this runs with still disabled APIC, but that's
+	 * ok because only the vector is set up. We still do another
+	 * check for the banks later for CPU #0 just to make sure
+	 * to not miss any events.
+	 */
+	apic_write(APIC_LVTCMCI, THRESHOLD_APIC_VECTOR|APIC_DM_FIXED);
+	cmci_recheck();
+}
+
+void mce_intel_feature_init(struct cpuinfo_x86 *c)
+{
+	intel_init_thermal(c);
+	intel_init_cmci();
+}

arch/x86/kernel/cpu/mcheck/p5.c

@@ -0,0 +1,66 @@
+/*
+ * P5 specific Machine Check Exception Reporting
+ * (C) Copyright 2002 Alan Cox <alan@lxorguk.ukuu.org.uk>
+ */
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/smp.h>
+
+#include <asm/processor.h>
+#include <asm/mce.h>
+#include <asm/msr.h>
+
+/* By default disabled */
+int mce_p5_enabled __read_mostly;
+
+/* Machine check handler for Pentium class Intel CPUs: */
+static void pentium_machine_check(struct pt_regs *regs, long error_code)
+{
+	u32 loaddr, hi, lotype;
+
+	rdmsr(MSR_IA32_P5_MC_ADDR, loaddr, hi);
+	rdmsr(MSR_IA32_P5_MC_TYPE, lotype, hi);
+
+	printk(KERN_EMERG
+		"CPU#%d: Machine Check Exception:  0x%8X (type 0x%8X).\n",
+		smp_processor_id(), loaddr, lotype);
+
+	if (lotype & (1<<5)) {
+		printk(KERN_EMERG
+			"CPU#%d: Possible thermal failure (CPU on fire ?).\n",
+			smp_processor_id());
+	}
+
+	add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
+}
+
+/* Set up machine check reporting for processors with Intel style MCE: */
+void intel_p5_mcheck_init(struct cpuinfo_x86 *c)
+{
+	u32 l, h;
+
+	/* Default P5 to off as its often misconnected: */
+	if (!mce_p5_enabled)
+		return;
+
+	/* Check for MCE support: */
+	if (!cpu_has(c, X86_FEATURE_MCE))
+		return;
+
+	machine_check_vector = pentium_machine_check;
+	/* Make sure the vector pointer is visible before we enable MCEs: */
+	wmb();
+
+	/* Read registers before enabling: */
+	rdmsr(MSR_IA32_P5_MC_ADDR, l, h);
+	rdmsr(MSR_IA32_P5_MC_TYPE, l, h);
+	printk(KERN_INFO
+	       "Intel old style machine check architecture supported.\n");
+
+	/* Enable MCE: */
+	set_in_cr4(X86_CR4_MCE);
+	printk(KERN_INFO
+	       "Intel old style machine check reporting enabled on CPU#%d.\n",
+	       smp_processor_id());
+}

arch/x86/kernel/cpu/mcheck/therm_throt.c

@@ -0,0 +1,573 @@
+/*
+ * Thermal throttle event support code (such as syslog messaging and rate
+ * limiting) that was factored out from x86_64 (mce_intel.c) and i386 (p4.c).
+ *
+ * This allows consistent reporting of CPU thermal throttle events.
+ *
+ * Maintains a counter in /sys that keeps track of the number of thermal
+ * events, such that the user knows how bad the thermal problem might be
+ * (since the logging to syslog and mcelog is rate limited).
+ *
+ * Author: Dmitriy Zavin (dmitriyz@google.com)
+ *
+ * Credits: Adapted from Zwane Mwaikambo's original code in mce_intel.c.
+ *          Inspired by Ross Biro's and Al Borchers' counter code.
+ */
+#include <linux/interrupt.h>
+#include <linux/notifier.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/percpu.h>
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/cpu.h>
+
+#include <asm/processor.h>
+#include <asm/apic.h>
+#include <asm/idle.h>
+#include <asm/mce.h>
+#include <asm/msr.h>
+#include <asm/trace/irq_vectors.h>
+
+/* How long to wait between reporting thermal events */
+#define CHECK_INTERVAL		(300 * HZ)
+
+#define THERMAL_THROTTLING_EVENT	0
+#define POWER_LIMIT_EVENT		1
+
+/*
+ * Current thermal event state:
+ */
+struct _thermal_state {
+	bool			new_event;
+	int			event;
+	u64			next_check;
+	unsigned long		count;
+	unsigned long		last_count;
+};
+
+struct thermal_state {
+	struct _thermal_state core_throttle;
+	struct _thermal_state core_power_limit;
+	struct _thermal_state package_throttle;
+	struct _thermal_state package_power_limit;
+	struct _thermal_state core_thresh0;
+	struct _thermal_state core_thresh1;
+	struct _thermal_state pkg_thresh0;
+	struct _thermal_state pkg_thresh1;
+};
+
+/* Callback to handle core threshold interrupts */
+int (*platform_thermal_notify)(__u64 msr_val);
+EXPORT_SYMBOL(platform_thermal_notify);
+
+/* Callback to handle core package threshold_interrupts */
+int (*platform_thermal_package_notify)(__u64 msr_val);
+EXPORT_SYMBOL_GPL(platform_thermal_package_notify);
+
+/* Callback support of rate control, return true, if
+ * callback has rate control */
+bool (*platform_thermal_package_rate_control)(void);
+EXPORT_SYMBOL_GPL(platform_thermal_package_rate_control);
+
+
+static DEFINE_PER_CPU(struct thermal_state, thermal_state);
+
+static atomic_t therm_throt_en	= ATOMIC_INIT(0);
+
+static u32 lvtthmr_init __read_mostly;
+
+#ifdef CONFIG_SYSFS
+#define define_therm_throt_device_one_ro(_name)				\
+	static DEVICE_ATTR(_name, 0444,					\
+			   therm_throt_device_show_##_name,		\
+				   NULL)				\
+
+#define define_therm_throt_device_show_func(event, name)		\
+									\
+static ssize_t therm_throt_device_show_##event##_##name(		\
+			struct device *dev,				\
+			struct device_attribute *attr,			\
+			char *buf)					\
+{									\
+	unsigned int cpu = dev->id;					\
+	ssize_t ret;							\
+									\
+	preempt_disable();	/* CPU hotplug */			\
+	if (cpu_online(cpu)) {						\
+		ret = sprintf(buf, "%lu\n",				\
+			      per_cpu(thermal_state, cpu).event.name);	\
+	} else								\
+		ret = 0;						\
+	preempt_enable();						\
+									\
+	return ret;							\
+}
+
+define_therm_throt_device_show_func(core_throttle, count);
+define_therm_throt_device_one_ro(core_throttle_count);
+
+define_therm_throt_device_show_func(core_power_limit, count);
+define_therm_throt_device_one_ro(core_power_limit_count);
+
+define_therm_throt_device_show_func(package_throttle, count);
+define_therm_throt_device_one_ro(package_throttle_count);
+
+define_therm_throt_device_show_func(package_power_limit, count);
+define_therm_throt_device_one_ro(package_power_limit_count);
+
+static struct attribute *thermal_throttle_attrs[] = {
+	&dev_attr_core_throttle_count.attr,
+	NULL
+};
+
+static struct attribute_group thermal_attr_group = {
+	.attrs	= thermal_throttle_attrs,
+	.name	= "thermal_throttle"
+};
+#endif /* CONFIG_SYSFS */
+
+#define CORE_LEVEL	0
+#define PACKAGE_LEVEL	1
+
+/***
+ * therm_throt_process - Process thermal throttling event from interrupt
+ * @curr: Whether the condition is current or not (boolean), since the
+ *        thermal interrupt normally gets called both when the thermal
+ *        event begins and once the event has ended.
+ *
+ * This function is called by the thermal interrupt after the
+ * IRQ has been acknowledged.
+ *
+ * It will take care of rate limiting and printing messages to the syslog.
+ *
+ * Returns: 0 : Event should NOT be further logged, i.e. still in
+ *              "timeout" from previous log message.
+ *          1 : Event should be logged further, and a message has been
+ *              printed to the syslog.
+ */
+static int therm_throt_process(bool new_event, int event, int level)
+{
+	struct _thermal_state *state;
+	unsigned int this_cpu = smp_processor_id();
+	bool old_event;
+	u64 now;
+	struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);
+
+	now = get_jiffies_64();
+	if (level == CORE_LEVEL) {
+		if (event == THERMAL_THROTTLING_EVENT)
+			state = &pstate->core_throttle;
+		else if (event == POWER_LIMIT_EVENT)
+			state = &pstate->core_power_limit;
+		else
+			 return 0;
+	} else if (level == PACKAGE_LEVEL) {
+		if (event == THERMAL_THROTTLING_EVENT)
+			state = &pstate->package_throttle;
+		else if (event == POWER_LIMIT_EVENT)
+			state = &pstate->package_power_limit;
+		else
+			return 0;
+	} else
+		return 0;
+
+	old_event = state->new_event;
+	state->new_event = new_event;
+
+	if (new_event)
+		state->count++;
+
+	if (time_before64(now, state->next_check) &&
+			state->count != state->last_count)
+		return 0;
+
+	state->next_check = now + CHECK_INTERVAL;
+	state->last_count = state->count;
+
+	/* if we just entered the thermal event */
+	if (new_event) {
+		if (event == THERMAL_THROTTLING_EVENT)
+			printk(KERN_CRIT "CPU%d: %s temperature above threshold, cpu clock throttled (total events = %lu)\n",
+				this_cpu,
+				level == CORE_LEVEL ? "Core" : "Package",
+				state->count);
+		return 1;
+	}
+	if (old_event) {
+		if (event == THERMAL_THROTTLING_EVENT)
+			printk(KERN_INFO "CPU%d: %s temperature/speed normal\n",
+				this_cpu,
+				level == CORE_LEVEL ? "Core" : "Package");
+		return 1;
+	}
+
+	return 0;
+}
+
+static int thresh_event_valid(int level, int event)
+{
+	struct _thermal_state *state;
+	unsigned int this_cpu = smp_processor_id();
+	struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);
+	u64 now = get_jiffies_64();
+
+	if (level == PACKAGE_LEVEL)
+		state = (event == 0) ? &pstate->pkg_thresh0 :
+						&pstate->pkg_thresh1;
+	else
+		state = (event == 0) ? &pstate->core_thresh0 :
+						&pstate->core_thresh1;
+
+	if (time_before64(now, state->next_check))
+		return 0;
+
+	state->next_check = now + CHECK_INTERVAL;
+
+	return 1;
+}
+
+static bool int_pln_enable;
+static int __init int_pln_enable_setup(char *s)
+{
+	int_pln_enable = true;
+
+	return 1;
+}
+__setup("int_pln_enable", int_pln_enable_setup);
+
+#ifdef CONFIG_SYSFS
+/* Add/Remove thermal_throttle interface for CPU device: */
+static int thermal_throttle_add_dev(struct device *dev, unsigned int cpu)
+{
+	int err;
+	struct cpuinfo_x86 *c = &cpu_data(cpu);
+
+	err = sysfs_create_group(&dev->kobj, &thermal_attr_group);
+	if (err)
+		return err;
+
+	if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)
+		err = sysfs_add_file_to_group(&dev->kobj,
+					      &dev_attr_core_power_limit_count.attr,
+					      thermal_attr_group.name);
+	if (cpu_has(c, X86_FEATURE_PTS)) {
+		err = sysfs_add_file_to_group(&dev->kobj,
+					      &dev_attr_package_throttle_count.attr,
+					      thermal_attr_group.name);
+		if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)
+			err = sysfs_add_file_to_group(&dev->kobj,
+					&dev_attr_package_power_limit_count.attr,
+					thermal_attr_group.name);
+	}
+
+	return err;
+}
+
+static void thermal_throttle_remove_dev(struct device *dev)
+{
+	sysfs_remove_group(&dev->kobj, &thermal_attr_group);
+}
+
+/* Get notified when a cpu comes on/off. Be hotplug friendly. */
+static int
+thermal_throttle_cpu_callback(struct notifier_block *nfb,
+			      unsigned long action,
+			      void *hcpu)
+{
+	unsigned int cpu = (unsigned long)hcpu;
+	struct device *dev;
+	int err = 0;
+
+	dev = get_cpu_device(cpu);
+
+	switch (action) {
+	case CPU_UP_PREPARE:
+	case CPU_UP_PREPARE_FROZEN:
+		err = thermal_throttle_add_dev(dev, cpu);
+		WARN_ON(err);
+		break;
+	case CPU_UP_CANCELED:
+	case CPU_UP_CANCELED_FROZEN:
+	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
+		thermal_throttle_remove_dev(dev);
+		break;
+	}
+	return notifier_from_errno(err);
+}
+
+static struct notifier_block thermal_throttle_cpu_notifier =
+{
+	.notifier_call = thermal_throttle_cpu_callback,
+};
+
+static __init int thermal_throttle_init_device(void)
+{
+	unsigned int cpu = 0;
+	int err;
+
+	if (!atomic_read(&therm_throt_en))
+		return 0;
+
+	cpu_notifier_register_begin();
+
+	/* connect live CPUs to sysfs */
+	for_each_online_cpu(cpu) {
+		err = thermal_throttle_add_dev(get_cpu_device(cpu), cpu);
+		WARN_ON(err);
+	}
+
+	__register_hotcpu_notifier(&thermal_throttle_cpu_notifier);
+	cpu_notifier_register_done();
+
+	return 0;
+}
+device_initcall(thermal_throttle_init_device);
+
+#endif /* CONFIG_SYSFS */
+
+static void notify_package_thresholds(__u64 msr_val)
+{
+	bool notify_thres_0 = false;
+	bool notify_thres_1 = false;
+
+	if (!platform_thermal_package_notify)
+		return;
+
+	/* lower threshold check */
+	if (msr_val & THERM_LOG_THRESHOLD0)
+		notify_thres_0 = true;
+	/* higher threshold check */
+	if (msr_val & THERM_LOG_THRESHOLD1)
+		notify_thres_1 = true;
+
+	if (!notify_thres_0 && !notify_thres_1)
+		return;
+
+	if (platform_thermal_package_rate_control &&
+		platform_thermal_package_rate_control()) {
+		/* Rate control is implemented in callback */
+		platform_thermal_package_notify(msr_val);
+		return;
+	}
+
+	/* lower threshold reached */
+	if (notify_thres_0 && thresh_event_valid(PACKAGE_LEVEL, 0))
+		platform_thermal_package_notify(msr_val);
+	/* higher threshold reached */
+	if (notify_thres_1 && thresh_event_valid(PACKAGE_LEVEL, 1))
+		platform_thermal_package_notify(msr_val);
+}
+
+static void notify_thresholds(__u64 msr_val)
+{
+	/* check whether the interrupt handler is defined;
+	 * otherwise simply return
+	 */
+	if (!platform_thermal_notify)
+		return;
+
+	/* lower threshold reached */
+	if ((msr_val & THERM_LOG_THRESHOLD0) &&
+			thresh_event_valid(CORE_LEVEL, 0))
+		platform_thermal_notify(msr_val);
+	/* higher threshold reached */
+	if ((msr_val & THERM_LOG_THRESHOLD1) &&
+			thresh_event_valid(CORE_LEVEL, 1))
+		platform_thermal_notify(msr_val);
+}
+
+/* Thermal transition interrupt handler */
+static void intel_thermal_interrupt(void)
+{
+	__u64 msr_val;
+
+	rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
+
+	/* Check for violation of core thermal thresholds*/
+	notify_thresholds(msr_val);
+
+	if (therm_throt_process(msr_val & THERM_STATUS_PROCHOT,
+				THERMAL_THROTTLING_EVENT,
+				CORE_LEVEL) != 0)
+		mce_log_therm_throt_event(msr_val);
+
+	if (this_cpu_has(X86_FEATURE_PLN) && int_pln_enable)
+		therm_throt_process(msr_val & THERM_STATUS_POWER_LIMIT,
+					POWER_LIMIT_EVENT,
+					CORE_LEVEL);
+
+	if (this_cpu_has(X86_FEATURE_PTS)) {
+		rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
+		/* check violations of package thermal thresholds */
+		notify_package_thresholds(msr_val);
+		therm_throt_process(msr_val & PACKAGE_THERM_STATUS_PROCHOT,
+					THERMAL_THROTTLING_EVENT,
+					PACKAGE_LEVEL);
+		if (this_cpu_has(X86_FEATURE_PLN) && int_pln_enable)
+			therm_throt_process(msr_val &
+					PACKAGE_THERM_STATUS_POWER_LIMIT,
+					POWER_LIMIT_EVENT,
+					PACKAGE_LEVEL);
+	}
+}
+
+static void unexpected_thermal_interrupt(void)
+{
+	printk(KERN_ERR "CPU%d: Unexpected LVT thermal interrupt!\n",
+			smp_processor_id());
+}
+
+static void (*smp_thermal_vector)(void) = unexpected_thermal_interrupt;
+
+static inline void __smp_thermal_interrupt(void)
+{
+	inc_irq_stat(irq_thermal_count);
+	smp_thermal_vector();
+}
+
+asmlinkage __visible void smp_thermal_interrupt(struct pt_regs *regs)
+{
+	entering_irq();
+	__smp_thermal_interrupt();
+	exiting_ack_irq();
+}
+
+asmlinkage __visible void smp_trace_thermal_interrupt(struct pt_regs *regs)
+{
+	entering_irq();
+	trace_thermal_apic_entry(THERMAL_APIC_VECTOR);
+	__smp_thermal_interrupt();
+	trace_thermal_apic_exit(THERMAL_APIC_VECTOR);
+	exiting_ack_irq();
+}
+
+/* Thermal monitoring depends on APIC, ACPI and clock modulation */
+static int intel_thermal_supported(struct cpuinfo_x86 *c)
+{
+	if (!cpu_has_apic)
+		return 0;
+	if (!cpu_has(c, X86_FEATURE_ACPI) || !cpu_has(c, X86_FEATURE_ACC))
+		return 0;
+	return 1;
+}
+
+void __init mcheck_intel_therm_init(void)
+{
+	/*
+	 * This function is only called on boot CPU. Save the init thermal
+	 * LVT value on BSP and use that value to restore APs' thermal LVT
+	 * entry BIOS programmed later
+	 */
+	if (intel_thermal_supported(&boot_cpu_data))
+		lvtthmr_init = apic_read(APIC_LVTTHMR);
+}
+
+void intel_init_thermal(struct cpuinfo_x86 *c)
+{
+	unsigned int cpu = smp_processor_id();
+	int tm2 = 0;
+	u32 l, h;
+
+	if (!intel_thermal_supported(c))
+		return;
+
+	/*
+	 * First check if its enabled already, in which case there might
+	 * be some SMM goo which handles it, so we can't even put a handler
+	 * since it might be delivered via SMI already:
+	 */
+	rdmsr(MSR_IA32_MISC_ENABLE, l, h);
+
+	h = lvtthmr_init;
+	/*
+	 * The initial value of thermal LVT entries on all APs always reads
+	 * 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI
+	 * sequence to them and LVT registers are reset to 0s except for
+	 * the mask bits which are set to 1s when APs receive INIT IPI.
+	 * If BIOS takes over the thermal interrupt and sets its interrupt
+	 * delivery mode to SMI (not fixed), it restores the value that the
+	 * BIOS has programmed on AP based on BSP's info we saved since BIOS
+	 * is always setting the same value for all threads/cores.
+	 */
+	if ((h & APIC_DM_FIXED_MASK) != APIC_DM_FIXED)
+		apic_write(APIC_LVTTHMR, lvtthmr_init);
+
+
+	if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) {
+		if (system_state == SYSTEM_BOOTING)
+			printk(KERN_DEBUG "CPU%d: Thermal monitoring handled by SMI\n", cpu);
+		return;
+	}
+
+	/* Check whether a vector already exists */
+	if (h & APIC_VECTOR_MASK) {
+		printk(KERN_DEBUG
+		       "CPU%d: Thermal LVT vector (%#x) already installed\n",
+		       cpu, (h & APIC_VECTOR_MASK));
+		return;
+	}
+
+	/* early Pentium M models use different method for enabling TM2 */
+	if (cpu_has(c, X86_FEATURE_TM2)) {
+		if (c->x86 == 6 && (c->x86_model == 9 || c->x86_model == 13)) {
+			rdmsr(MSR_THERM2_CTL, l, h);
+			if (l & MSR_THERM2_CTL_TM_SELECT)
+				tm2 = 1;
+		} else if (l & MSR_IA32_MISC_ENABLE_TM2)
+			tm2 = 1;
+	}
+
+	/* We'll mask the thermal vector in the lapic till we're ready: */
+	h = THERMAL_APIC_VECTOR | APIC_DM_FIXED | APIC_LVT_MASKED;
+	apic_write(APIC_LVTTHMR, h);
+
+	rdmsr(MSR_IA32_THERM_INTERRUPT, l, h);
+	if (cpu_has(c, X86_FEATURE_PLN) && !int_pln_enable)
+		wrmsr(MSR_IA32_THERM_INTERRUPT,
+			(l | (THERM_INT_LOW_ENABLE
+			| THERM_INT_HIGH_ENABLE)) & ~THERM_INT_PLN_ENABLE, h);
+	else if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)
+		wrmsr(MSR_IA32_THERM_INTERRUPT,
+			l | (THERM_INT_LOW_ENABLE
+			| THERM_INT_HIGH_ENABLE | THERM_INT_PLN_ENABLE), h);
+	else
+		wrmsr(MSR_IA32_THERM_INTERRUPT,
+		      l | (THERM_INT_LOW_ENABLE | THERM_INT_HIGH_ENABLE), h);
+
+	if (cpu_has(c, X86_FEATURE_PTS)) {
+		rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
+		if (cpu_has(c, X86_FEATURE_PLN) && !int_pln_enable)
+			wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
+				(l | (PACKAGE_THERM_INT_LOW_ENABLE
+				| PACKAGE_THERM_INT_HIGH_ENABLE))
+				& ~PACKAGE_THERM_INT_PLN_ENABLE, h);
+		else if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)
+			wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
+				l | (PACKAGE_THERM_INT_LOW_ENABLE
+				| PACKAGE_THERM_INT_HIGH_ENABLE
+				| PACKAGE_THERM_INT_PLN_ENABLE), h);
+		else
+			wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
+			      l | (PACKAGE_THERM_INT_LOW_ENABLE
+				| PACKAGE_THERM_INT_HIGH_ENABLE), h);
+	}
+
+	smp_thermal_vector = intel_thermal_interrupt;
+
+	rdmsr(MSR_IA32_MISC_ENABLE, l, h);
+	wrmsr(MSR_IA32_MISC_ENABLE, l | MSR_IA32_MISC_ENABLE_TM1, h);
+
+	/* Unmask the thermal vector: */
+	l = apic_read(APIC_LVTTHMR);
+	apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
+
+	printk_once(KERN_INFO "CPU0: Thermal monitoring enabled (%s)\n",
+		       tm2 ? "TM2" : "TM1");
+
+	/* enable thermal throttle processing */
+	atomic_set(&therm_throt_en, 1);
+}

arch/x86/kernel/cpu/mcheck/threshold.c

@@ -0,0 +1,41 @@
+/*
+ * Common corrected MCE threshold handler code:
+ */
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+
+#include <asm/irq_vectors.h>
+#include <asm/apic.h>
+#include <asm/idle.h>
+#include <asm/mce.h>
+#include <asm/trace/irq_vectors.h>
+
+static void default_threshold_interrupt(void)
+{
+	printk(KERN_ERR "Unexpected threshold interrupt at vector %x\n",
+			 THRESHOLD_APIC_VECTOR);
+}
+
+void (*mce_threshold_vector)(void) = default_threshold_interrupt;
+
+static inline void __smp_threshold_interrupt(void)
+{
+	inc_irq_stat(irq_threshold_count);
+	mce_threshold_vector();
+}
+
+asmlinkage __visible void smp_threshold_interrupt(void)
+{
+	entering_irq();
+	__smp_threshold_interrupt();
+	exiting_ack_irq();
+}
+
+asmlinkage __visible void smp_trace_threshold_interrupt(void)
+{
+	entering_irq();
+	trace_threshold_apic_entry(THRESHOLD_APIC_VECTOR);
+	__smp_threshold_interrupt();
+	trace_threshold_apic_exit(THRESHOLD_APIC_VECTOR);
+	exiting_ack_irq();
+}

arch/x86/kernel/cpu/mcheck/winchip.c

@@ -0,0 +1,38 @@
+/*
+ * IDT Winchip specific Machine Check Exception Reporting
+ * (C) Copyright 2002 Alan Cox <alan@lxorguk.ukuu.org.uk>
+ */
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+
+#include <asm/processor.h>
+#include <asm/mce.h>
+#include <asm/msr.h>
+
+/* Machine check handler for WinChip C6: */
+static void winchip_machine_check(struct pt_regs *regs, long error_code)
+{
+	printk(KERN_EMERG "CPU0: Machine Check Exception.\n");
+	add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
+}
+
+/* Set up machine check reporting on the Winchip C6 series */
+void winchip_mcheck_init(struct cpuinfo_x86 *c)
+{
+	u32 lo, hi;
+
+	machine_check_vector = winchip_machine_check;
+	/* Make sure the vector pointer is visible before we enable MCEs: */
+	wmb();
+
+	rdmsr(MSR_IDT_FCR1, lo, hi);
+	lo |= (1<<2);	/* Enable EIERRINT (int 18 MCE) */
+	lo &= ~(1<<4);	/* Enable MCE */
+	wrmsr(MSR_IDT_FCR1, lo, hi);
+
+	set_in_cr4(X86_CR4_MCE);
+
+	printk(KERN_INFO
+	       "Winchip machine check reporting enabled on CPU#0.\n");
+}