Fixed MTP to work with TWRP

arch/x86/kernel/cpu/vmware.c

@@ -0,0 +1,147 @@
+/*
+ * VMware Detection code.
+ *
+ * Copyright (C) 2008, VMware, Inc.
+ * Author : Alok N Kataria <akataria@vmware.com>
+ *
+ * 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, GOOD TITLE or
+ * NON INFRINGEMENT.  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 St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <linux/dmi.h>
+#include <linux/module.h>
+#include <asm/div64.h>
+#include <asm/x86_init.h>
+#include <asm/hypervisor.h>
+
+#define CPUID_VMWARE_INFO_LEAF	0x40000000
+#define VMWARE_HYPERVISOR_MAGIC	0x564D5868
+#define VMWARE_HYPERVISOR_PORT	0x5658
+
+#define VMWARE_PORT_CMD_GETVERSION	10
+#define VMWARE_PORT_CMD_GETHZ		45
+#define VMWARE_PORT_CMD_GETVCPU_INFO	68
+#define VMWARE_PORT_CMD_LEGACY_X2APIC	3
+#define VMWARE_PORT_CMD_VCPU_RESERVED	31
+
+#define VMWARE_PORT(cmd, eax, ebx, ecx, edx)				\
+	__asm__("inl (%%dx)" :						\
+			"=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) :	\
+			"0"(VMWARE_HYPERVISOR_MAGIC),			\
+			"1"(VMWARE_PORT_CMD_##cmd),			\
+			"2"(VMWARE_HYPERVISOR_PORT), "3"(UINT_MAX) :	\
+			"memory");
+
+static inline int __vmware_platform(void)
+{
+	uint32_t eax, ebx, ecx, edx;
+	VMWARE_PORT(GETVERSION, eax, ebx, ecx, edx);
+	return eax != (uint32_t)-1 && ebx == VMWARE_HYPERVISOR_MAGIC;
+}
+
+static unsigned long vmware_get_tsc_khz(void)
+{
+	uint64_t tsc_hz, lpj;
+	uint32_t eax, ebx, ecx, edx;
+
+	VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
+
+	tsc_hz = eax | (((uint64_t)ebx) << 32);
+	do_div(tsc_hz, 1000);
+	BUG_ON(tsc_hz >> 32);
+	printk(KERN_INFO "TSC freq read from hypervisor : %lu.%03lu MHz\n",
+			 (unsigned long) tsc_hz / 1000,
+			 (unsigned long) tsc_hz % 1000);
+
+	if (!preset_lpj) {
+		lpj = ((u64)tsc_hz * 1000);
+		do_div(lpj, HZ);
+		preset_lpj = lpj;
+	}
+
+	return tsc_hz;
+}
+
+static void __init vmware_platform_setup(void)
+{
+	uint32_t eax, ebx, ecx, edx;
+
+	VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
+
+	if (ebx != UINT_MAX)
+		x86_platform.calibrate_tsc = vmware_get_tsc_khz;
+	else
+		printk(KERN_WARNING
+		       "Failed to get TSC freq from the hypervisor\n");
+}
+
+/*
+ * While checking the dmi string information, just checking the product
+ * serial key should be enough, as this will always have a VMware
+ * specific string when running under VMware hypervisor.
+ */
+static uint32_t __init vmware_platform(void)
+{
+	if (cpu_has_hypervisor) {
+		unsigned int eax;
+		unsigned int hyper_vendor_id[3];
+
+		cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &hyper_vendor_id[0],
+		      &hyper_vendor_id[1], &hyper_vendor_id[2]);
+		if (!memcmp(hyper_vendor_id, "VMwareVMware", 12))
+			return CPUID_VMWARE_INFO_LEAF;
+	} else if (dmi_available && dmi_name_in_serial("VMware") &&
+		   __vmware_platform())
+		return 1;
+
+	return 0;
+}
+
+/*
+ * VMware hypervisor takes care of exporting a reliable TSC to the guest.
+ * Still, due to timing difference when running on virtual cpus, the TSC can
+ * be marked as unstable in some cases. For example, the TSC sync check at
+ * bootup can fail due to a marginal offset between vcpus' TSCs (though the
+ * TSCs do not drift from each other).  Also, the ACPI PM timer clocksource
+ * is not suitable as a watchdog when running on a hypervisor because the
+ * kernel may miss a wrap of the counter if the vcpu is descheduled for a
+ * long time. To skip these checks at runtime we set these capability bits,
+ * so that the kernel could just trust the hypervisor with providing a
+ * reliable virtual TSC that is suitable for timekeeping.
+ */
+static void vmware_set_cpu_features(struct cpuinfo_x86 *c)
+{
+	set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
+	set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE);
+}
+
+/* Checks if hypervisor supports x2apic without VT-D interrupt remapping. */
+static bool __init vmware_legacy_x2apic_available(void)
+{
+	uint32_t eax, ebx, ecx, edx;
+	VMWARE_PORT(GETVCPU_INFO, eax, ebx, ecx, edx);
+	return (eax & (1 << VMWARE_PORT_CMD_VCPU_RESERVED)) == 0 &&
+	       (eax & (1 << VMWARE_PORT_CMD_LEGACY_X2APIC)) != 0;
+}
+
+const __refconst struct hypervisor_x86 x86_hyper_vmware = {
+	.name			= "VMware",
+	.detect			= vmware_platform,
+	.set_cpu_features	= vmware_set_cpu_features,
+	.init_platform		= vmware_platform_setup,
+	.x2apic_available	= vmware_legacy_x2apic_available,
+};
+EXPORT_SYMBOL(x86_hyper_vmware);