Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

arch/i386/kernel/cpu/mcheck/Makefile

@@ -0,0 +1,2 @@
+obj-y	=	mce.o k7.o p4.o p5.o p6.o winchip.o
+obj-$(CONFIG_X86_MCE_NONFATAL)	+=	non-fatal.o

arch/i386/kernel/cpu/mcheck/k7.c

@@ -0,0 +1,97 @@
+/*
+ * Athlon/Hammer specific Machine Check Exception Reporting
+ * (C) Copyright 2002 Dave Jones <davej@codemonkey.org.uk>
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/config.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/smp.h>
+
+#include <asm/processor.h> 
+#include <asm/system.h>
+#include <asm/msr.h>
+
+#include "mce.h"
+
+/* Machine Check Handler For AMD Athlon/Duron */
+static fastcall void k7_machine_check(struct pt_regs * regs, long error_code)
+{
+	int recover=1;
+	u32 alow, ahigh, high, low;
+	u32 mcgstl, mcgsth;
+	int i;
+
+	rdmsr (MSR_IA32_MCG_STATUS, mcgstl, mcgsth);
+	if (mcgstl & (1<<0))	/* Recoverable ? */
+		recover=0;
+
+	printk (KERN_EMERG "CPU %d: Machine Check Exception: %08x%08x\n",
+		smp_processor_id(), mcgsth, mcgstl);
+
+	for (i=1; i<nr_mce_banks; i++) {
+		rdmsr (MSR_IA32_MC0_STATUS+i*4,low, high);
+		if (high&(1<<31)) {
+			if (high & (1<<29))
+				recover |= 1;
+			if (high & (1<<25))
+				recover |= 2;
+			printk (KERN_EMERG "Bank %d: %08x%08x", i, high, low);
+			high &= ~(1<<31);
+			if (high & (1<<27)) {
+				rdmsr (MSR_IA32_MC0_MISC+i*4, alow, ahigh);
+				printk ("[%08x%08x]", ahigh, alow);
+			}
+			if (high & (1<<26)) {
+				rdmsr (MSR_IA32_MC0_ADDR+i*4, alow, ahigh);
+				printk (" at %08x%08x", ahigh, alow);
+			}
+			printk ("\n");
+			/* Clear it */
+			wrmsr (MSR_IA32_MC0_STATUS+i*4, 0UL, 0UL);
+			/* Serialize */
+			wmb();
+			add_taint(TAINT_MACHINE_CHECK);
+		}
+	}
+
+	if (recover&2)
+		panic ("CPU context corrupt");
+	if (recover&1)
+		panic ("Unable to continue");
+	printk (KERN_EMERG "Attempting to continue.\n");
+	mcgstl &= ~(1<<2);
+	wrmsr (MSR_IA32_MCG_STATUS,mcgstl, mcgsth);
+}
+
+
+/* AMD K7 machine check is Intel like */
+void __init amd_mcheck_init(struct cpuinfo_x86 *c)
+{
+	u32 l, h;
+	int i;
+
+	machine_check_vector = k7_machine_check;
+	wmb();
+
+	printk (KERN_INFO "Intel machine check architecture supported.\n");
+	rdmsr (MSR_IA32_MCG_CAP, l, h);
+	if (l & (1<<8))	/* Control register present ? */
+		wrmsr (MSR_IA32_MCG_CTL, 0xffffffff, 0xffffffff);
+	nr_mce_banks = l & 0xff;
+
+	/* Clear status for MC index 0 separately, we don't touch CTL,
+	 * as some Athlons cause spurious MCEs when its enabled. */
+	wrmsr (MSR_IA32_MC0_STATUS, 0x0, 0x0);
+	for (i=1; i<nr_mce_banks; i++) {
+		wrmsr (MSR_IA32_MC0_CTL+4*i, 0xffffffff, 0xffffffff);
+		wrmsr (MSR_IA32_MC0_STATUS+4*i, 0x0, 0x0);
+	}
+
+	set_in_cr4 (X86_CR4_MCE);
+	printk (KERN_INFO "Intel machine check reporting enabled on CPU#%d.\n",
+		smp_processor_id());
+}

arch/i386/kernel/cpu/mcheck/mce.c

@@ -0,0 +1,77 @@
+/*
+ * mce.c - x86 Machine Check Exception Reporting
+ * (c) 2002 Alan Cox <alan@redhat.com>, Dave Jones <davej@codemonkey.org.uk>
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/smp.h>
+#include <linux/thread_info.h>
+
+#include <asm/processor.h> 
+#include <asm/system.h>
+
+#include "mce.h"
+
+int mce_disabled __initdata = 0;
+int nr_mce_banks;
+
+EXPORT_SYMBOL_GPL(nr_mce_banks);	/* non-fatal.o */
+
+/* Handle unconfigured int18 (should never happen) */
+static fastcall void unexpected_machine_check(struct pt_regs * regs, long error_code)
+{	
+	printk(KERN_ERR "CPU#%d: Unexpected int18 (Machine Check).\n", smp_processor_id());
+}
+
+/* Call the installed machine check handler for this CPU setup. */
+void fastcall (*machine_check_vector)(struct pt_regs *, long error_code) = unexpected_machine_check;
+
+/* This has to be run for each processor */
+void __init mcheck_init(struct cpuinfo_x86 *c)
+{
+	if (mce_disabled==1)
+		return;
+
+	switch (c->x86_vendor) {
+		case X86_VENDOR_AMD:
+			if (c->x86==6 || c->x86==15)
+				amd_mcheck_init(c);
+			break;
+
+		case X86_VENDOR_INTEL:
+			if (c->x86==5)
+				intel_p5_mcheck_init(c);
+			if (c->x86==6)
+				intel_p6_mcheck_init(c);
+			if (c->x86==15)
+				intel_p4_mcheck_init(c);
+			break;
+
+		case X86_VENDOR_CENTAUR:
+			if (c->x86==5)
+				winchip_mcheck_init(c);
+			break;
+
+		default:
+			break;
+	}
+}
+
+static int __init mcheck_disable(char *str)
+{
+	mce_disabled = 1;
+	return 0;
+}
+
+static int __init mcheck_enable(char *str)
+{
+	mce_disabled = -1;
+	return 0;
+}
+
+__setup("nomce", mcheck_disable);
+__setup("mce", mcheck_enable);

arch/i386/kernel/cpu/mcheck/mce.h

@@ -0,0 +1,14 @@
+#include <linux/init.h>
+
+void amd_mcheck_init(struct cpuinfo_x86 *c);
+void intel_p4_mcheck_init(struct cpuinfo_x86 *c);
+void intel_p5_mcheck_init(struct cpuinfo_x86 *c);
+void intel_p6_mcheck_init(struct cpuinfo_x86 *c);
+void winchip_mcheck_init(struct cpuinfo_x86 *c);
+
+/* Call the installed machine check handler for this CPU setup. */
+extern fastcall void (*machine_check_vector)(struct pt_regs *, long error_code);
+
+extern int mce_disabled __initdata;
+extern int nr_mce_banks;
+

arch/i386/kernel/cpu/mcheck/non-fatal.c

@@ -0,0 +1,93 @@
+/*
+ * Non Fatal Machine Check Exception Reporting
+ *
+ * (C) Copyright 2002 Dave Jones. <davej@codemonkey.org.uk>
+ *
+ * This file contains routines to check for non-fatal MCEs every 15s
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+#include <linux/config.h>
+#include <linux/irq.h>
+#include <linux/workqueue.h>
+#include <linux/interrupt.h>
+#include <linux/smp.h>
+#include <linux/module.h>
+
+#include <asm/processor.h> 
+#include <asm/system.h>
+#include <asm/msr.h>
+
+#include "mce.h"
+
+static int firstbank;
+
+#define MCE_RATE	15*HZ	/* timer rate is 15s */
+
+static void mce_checkregs (void *info)
+{
+	u32 low, high;
+	int i;
+
+	for (i=firstbank; i<nr_mce_banks; i++) {
+		rdmsr (MSR_IA32_MC0_STATUS+i*4, low, high);
+
+		if (high & (1<<31)) {
+			printk(KERN_INFO "MCE: The hardware reports a non "
+				"fatal, correctable incident occurred on "
+				"CPU %d.\n",
+				smp_processor_id());
+			printk (KERN_INFO "Bank %d: %08x%08x\n", i, high, low);
+
+			/* Scrub the error so we don't pick it up in MCE_RATE seconds time. */
+			wrmsr (MSR_IA32_MC0_STATUS+i*4, 0UL, 0UL);
+
+			/* Serialize */
+			wmb();
+			add_taint(TAINT_MACHINE_CHECK);
+		}
+	}
+}
+
+static void mce_work_fn(void *data);
+static DECLARE_WORK(mce_work, mce_work_fn, NULL);
+
+static void mce_work_fn(void *data)
+{ 
+	on_each_cpu(mce_checkregs, NULL, 1, 1);
+	schedule_delayed_work(&mce_work, MCE_RATE);
+} 
+
+static int __init init_nonfatal_mce_checker(void)
+{
+	struct cpuinfo_x86 *c = &boot_cpu_data;
+
+	/* Check for MCE support */
+	if (!cpu_has(c, X86_FEATURE_MCE))
+		return -ENODEV;
+
+	/* Check for PPro style MCA */
+	if (!cpu_has(c, X86_FEATURE_MCA))
+		return -ENODEV;
+
+	/* Some Athlons misbehave when we frob bank 0 */
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
+		boot_cpu_data.x86 == 6)
+			firstbank = 1;
+	else
+			firstbank = 0;
+
+	/*
+	 * Check for non-fatal errors every MCE_RATE s
+	 */
+	schedule_delayed_work(&mce_work, MCE_RATE);
+	printk(KERN_INFO "Machine check exception polling timer started.\n");
+	return 0;
+}
+module_init(init_nonfatal_mce_checker);
+
+MODULE_LICENSE("GPL");

arch/i386/kernel/cpu/mcheck/p4.c

@@ -0,0 +1,271 @@
+/*
+ * P4 specific Machine Check Exception Reporting
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/config.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/smp.h>
+
+#include <asm/processor.h> 
+#include <asm/system.h>
+#include <asm/msr.h>
+#include <asm/apic.h>
+
+#include "mce.h"
+
+/* as supported by the P4/Xeon family */
+struct intel_mce_extended_msrs {
+	u32 eax;
+	u32 ebx;
+	u32 ecx;
+	u32 edx;
+	u32 esi;
+	u32 edi;
+	u32 ebp;
+	u32 esp;
+	u32 eflags;
+	u32 eip;
+	/* u32 *reserved[]; */
+};
+
+static int mce_num_extended_msrs = 0;
+
+
+#ifdef CONFIG_X86_MCE_P4THERMAL
+static void unexpected_thermal_interrupt(struct pt_regs *regs)
+{	
+	printk(KERN_ERR "CPU%d: Unexpected LVT TMR interrupt!\n",
+			smp_processor_id());
+	add_taint(TAINT_MACHINE_CHECK);
+}
+
+/* P4/Xeon Thermal transition interrupt handler */
+static void intel_thermal_interrupt(struct pt_regs *regs)
+{
+	u32 l, h;
+	unsigned int cpu = smp_processor_id();
+	static unsigned long next[NR_CPUS];
+
+	ack_APIC_irq();
+
+	if (time_after(next[cpu], jiffies))
+		return;
+
+	next[cpu] = jiffies + HZ*5;
+	rdmsr(MSR_IA32_THERM_STATUS, l, h);
+	if (l & 0x1) {
+		printk(KERN_EMERG "CPU%d: Temperature above threshold\n", cpu);
+		printk(KERN_EMERG "CPU%d: Running in modulated clock mode\n",
+				cpu);
+		add_taint(TAINT_MACHINE_CHECK);
+	} else {
+		printk(KERN_INFO "CPU%d: Temperature/speed normal\n", cpu);
+	}
+}
+
+/* Thermal interrupt handler for this CPU setup */
+static void (*vendor_thermal_interrupt)(struct pt_regs *regs) = unexpected_thermal_interrupt;
+
+fastcall void smp_thermal_interrupt(struct pt_regs *regs)
+{
+	irq_enter();
+	vendor_thermal_interrupt(regs);
+	irq_exit();
+}
+
+/* P4/Xeon Thermal regulation detect and init */
+static void __init intel_init_thermal(struct cpuinfo_x86 *c)
+{
+	u32 l, h;
+	unsigned int cpu = smp_processor_id();
+
+	/* Thermal monitoring */
+	if (!cpu_has(c, X86_FEATURE_ACPI))
+		return;	/* -ENODEV */
+
+	/* Clock modulation */
+	if (!cpu_has(c, X86_FEATURE_ACC))
+		return;	/* -ENODEV */
+
+	/* 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 -zwanem.
+	 */
+	rdmsr (MSR_IA32_MISC_ENABLE, l, h);
+	h = apic_read(APIC_LVTTHMR);
+	if ((l & (1<<3)) && (h & APIC_DM_SMI)) {
+		printk(KERN_DEBUG "CPU%d: Thermal monitoring handled by SMI\n",
+				cpu);
+		return; /* -EBUSY */
+	}
+
+	/* check whether a vector already exists, temporarily masked? */	
+	if (h & APIC_VECTOR_MASK) {
+		printk(KERN_DEBUG "CPU%d: Thermal LVT vector (%#x) already "
+				"installed\n",
+			cpu, (h & APIC_VECTOR_MASK));
+		return; /* -EBUSY */
+	}
+
+	/* The temperature transition interrupt handler setup */
+	h = THERMAL_APIC_VECTOR;		/* our delivery vector */
+	h |= (APIC_DM_FIXED | APIC_LVT_MASKED);	/* we'll mask till we're ready */
+	apic_write_around(APIC_LVTTHMR, h);
+
+	rdmsr (MSR_IA32_THERM_INTERRUPT, l, h);
+	wrmsr (MSR_IA32_THERM_INTERRUPT, l | 0x03 , h);
+
+	/* ok we're good to go... */
+	vendor_thermal_interrupt = intel_thermal_interrupt;
+	
+	rdmsr (MSR_IA32_MISC_ENABLE, l, h);
+	wrmsr (MSR_IA32_MISC_ENABLE, l | (1<<3), h);
+	
+	l = apic_read (APIC_LVTTHMR);
+	apic_write_around (APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
+	printk (KERN_INFO "CPU%d: Thermal monitoring enabled\n", cpu);
+	return;
+}
+#endif /* CONFIG_X86_MCE_P4THERMAL */
+
+
+/* P4/Xeon Extended MCE MSR retrieval, return 0 if unsupported */
+static inline int intel_get_extended_msrs(struct intel_mce_extended_msrs *r)
+{
+	u32 h;
+
+	if (mce_num_extended_msrs == 0)
+		goto done;
+
+	rdmsr (MSR_IA32_MCG_EAX, r->eax, h);
+	rdmsr (MSR_IA32_MCG_EBX, r->ebx, h);
+	rdmsr (MSR_IA32_MCG_ECX, r->ecx, h);
+	rdmsr (MSR_IA32_MCG_EDX, r->edx, h);
+	rdmsr (MSR_IA32_MCG_ESI, r->esi, h);
+	rdmsr (MSR_IA32_MCG_EDI, r->edi, h);
+	rdmsr (MSR_IA32_MCG_EBP, r->ebp, h);
+	rdmsr (MSR_IA32_MCG_ESP, r->esp, h);
+	rdmsr (MSR_IA32_MCG_EFLAGS, r->eflags, h);
+	rdmsr (MSR_IA32_MCG_EIP, r->eip, h);
+
+	/* can we rely on kmalloc to do a dynamic
+	 * allocation for the reserved registers?
+	 */
+done:
+	return mce_num_extended_msrs;
+}
+
+static fastcall void intel_machine_check(struct pt_regs * regs, long error_code)
+{
+	int recover=1;
+	u32 alow, ahigh, high, low;
+	u32 mcgstl, mcgsth;
+	int i;
+	struct intel_mce_extended_msrs dbg;
+
+	rdmsr (MSR_IA32_MCG_STATUS, mcgstl, mcgsth);
+	if (mcgstl & (1<<0))	/* Recoverable ? */
+		recover=0;
+
+	printk (KERN_EMERG "CPU %d: Machine Check Exception: %08x%08x\n",
+		smp_processor_id(), mcgsth, mcgstl);
+
+	if (intel_get_extended_msrs(&dbg)) {
+		printk (KERN_DEBUG "CPU %d: EIP: %08x EFLAGS: %08x\n",
+			smp_processor_id(), dbg.eip, dbg.eflags);
+		printk (KERN_DEBUG "\teax: %08x ebx: %08x ecx: %08x edx: %08x\n",
+			dbg.eax, dbg.ebx, dbg.ecx, dbg.edx);
+		printk (KERN_DEBUG "\tesi: %08x edi: %08x ebp: %08x esp: %08x\n",
+			dbg.esi, dbg.edi, dbg.ebp, dbg.esp);
+	}
+
+	for (i=0; i<nr_mce_banks; i++) {
+		rdmsr (MSR_IA32_MC0_STATUS+i*4,low, high);
+		if (high & (1<<31)) {
+			if (high & (1<<29))
+				recover |= 1;
+			if (high & (1<<25))
+				recover |= 2;
+			printk (KERN_EMERG "Bank %d: %08x%08x", i, high, low);
+			high &= ~(1<<31);
+			if (high & (1<<27)) {
+				rdmsr (MSR_IA32_MC0_MISC+i*4, alow, ahigh);
+				printk ("[%08x%08x]", ahigh, alow);
+			}
+			if (high & (1<<26)) {
+				rdmsr (MSR_IA32_MC0_ADDR+i*4, alow, ahigh);
+				printk (" at %08x%08x", ahigh, alow);
+			}
+			printk ("\n");
+		}
+	}
+
+	if (recover & 2)
+		panic ("CPU context corrupt");
+	if (recover & 1)
+		panic ("Unable to continue");
+
+	printk(KERN_EMERG "Attempting to continue.\n");
+	/* 
+	 * Do not clear the MSR_IA32_MCi_STATUS if the error is not 
+	 * recoverable/continuable.This will allow BIOS to look at the MSRs
+	 * for errors if the OS could not log the error.
+	 */
+	for (i=0; i<nr_mce_banks; i++) {
+		u32 msr;
+		msr = MSR_IA32_MC0_STATUS+i*4;
+		rdmsr (msr, low, high);
+		if (high&(1<<31)) {
+			/* Clear it */
+			wrmsr(msr, 0UL, 0UL);
+			/* Serialize */
+			wmb();
+			add_taint(TAINT_MACHINE_CHECK);
+		}
+	}
+	mcgstl &= ~(1<<2);
+	wrmsr (MSR_IA32_MCG_STATUS,mcgstl, mcgsth);
+}
+
+
+void __init intel_p4_mcheck_init(struct cpuinfo_x86 *c)
+{
+	u32 l, h;
+	int i;
+	
+	machine_check_vector = intel_machine_check;
+	wmb();
+
+	printk (KERN_INFO "Intel machine check architecture supported.\n");
+	rdmsr (MSR_IA32_MCG_CAP, l, h);
+	if (l & (1<<8))	/* Control register present ? */
+		wrmsr (MSR_IA32_MCG_CTL, 0xffffffff, 0xffffffff);
+	nr_mce_banks = l & 0xff;
+
+	for (i=0; i<nr_mce_banks; i++) {
+		wrmsr (MSR_IA32_MC0_CTL+4*i, 0xffffffff, 0xffffffff);
+		wrmsr (MSR_IA32_MC0_STATUS+4*i, 0x0, 0x0);
+	}
+
+	set_in_cr4 (X86_CR4_MCE);
+	printk (KERN_INFO "Intel machine check reporting enabled on CPU#%d.\n",
+		smp_processor_id());
+
+	/* Check for P4/Xeon extended MCE MSRs */
+	rdmsr (MSR_IA32_MCG_CAP, l, h);
+	if (l & (1<<9))	{/* MCG_EXT_P */
+		mce_num_extended_msrs = (l >> 16) & 0xff;
+		printk (KERN_INFO "CPU%d: Intel P4/Xeon Extended MCE MSRs (%d)"
+				" available\n",
+			smp_processor_id(), mce_num_extended_msrs);
+
+#ifdef CONFIG_X86_MCE_P4THERMAL
+		/* Check for P4/Xeon Thermal monitor */
+		intel_init_thermal(c);
+#endif
+	}
+}

arch/i386/kernel/cpu/mcheck/p5.c

@@ -0,0 +1,54 @@
+/*
+ * P5 specific Machine Check Exception Reporting
+ * (C) Copyright 2002 Alan Cox <alan@redhat.com>
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/smp.h>
+
+#include <asm/processor.h> 
+#include <asm/system.h>
+#include <asm/msr.h>
+
+#include "mce.h"
+
+/* Machine check handler for Pentium class Intel */
+static fastcall 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);
+}
+
+/* Set up machine check reporting for processors with Intel style MCE */
+void __init intel_p5_mcheck_init(struct cpuinfo_x86 *c)
+{
+	u32 l, h;
+	
+	/*Check for MCE support */
+	if( !cpu_has(c, X86_FEATURE_MCE) )
+		return;	
+
+	/* Default P5 to off as its often misconnected */
+	if(mce_disabled != -1)
+		return;
+	machine_check_vector = pentium_machine_check;
+	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/i386/kernel/cpu/mcheck/p6.c

@@ -0,0 +1,115 @@
+/*
+ * P6 specific Machine Check Exception Reporting
+ * (C) Copyright 2002 Alan Cox <alan@redhat.com>
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/smp.h>
+
+#include <asm/processor.h> 
+#include <asm/system.h>
+#include <asm/msr.h>
+
+#include "mce.h"
+
+/* Machine Check Handler For PII/PIII */
+static fastcall void intel_machine_check(struct pt_regs * regs, long error_code)
+{
+	int recover=1;
+	u32 alow, ahigh, high, low;
+	u32 mcgstl, mcgsth;
+	int i;
+
+	rdmsr (MSR_IA32_MCG_STATUS, mcgstl, mcgsth);
+	if (mcgstl & (1<<0))	/* Recoverable ? */
+		recover=0;
+
+	printk (KERN_EMERG "CPU %d: Machine Check Exception: %08x%08x\n",
+		smp_processor_id(), mcgsth, mcgstl);
+
+	for (i=0; i<nr_mce_banks; i++) {
+		rdmsr (MSR_IA32_MC0_STATUS+i*4,low, high);
+		if (high & (1<<31)) {
+			if (high & (1<<29))
+				recover |= 1;
+			if (high & (1<<25))
+				recover |= 2;
+			printk (KERN_EMERG "Bank %d: %08x%08x", i, high, low);
+			high &= ~(1<<31);
+			if (high & (1<<27)) {
+				rdmsr (MSR_IA32_MC0_MISC+i*4, alow, ahigh);
+				printk ("[%08x%08x]", ahigh, alow);
+			}
+			if (high & (1<<26)) {
+				rdmsr (MSR_IA32_MC0_ADDR+i*4, alow, ahigh);
+				printk (" at %08x%08x", ahigh, alow);
+			}
+			printk ("\n");
+		}
+	}
+
+	if (recover & 2)
+		panic ("CPU context corrupt");
+	if (recover & 1)
+		panic ("Unable to continue");
+
+	printk (KERN_EMERG "Attempting to continue.\n");
+	/* 
+	 * Do not clear the MSR_IA32_MCi_STATUS if the error is not 
+	 * recoverable/continuable.This will allow BIOS to look at the MSRs
+	 * for errors if the OS could not log the error.
+	 */
+	for (i=0; i<nr_mce_banks; i++) {
+		unsigned int msr;
+		msr = MSR_IA32_MC0_STATUS+i*4;
+		rdmsr (msr,low, high);
+		if (high & (1<<31)) {
+			/* Clear it */
+			wrmsr (msr, 0UL, 0UL);
+			/* Serialize */
+			wmb();
+			add_taint(TAINT_MACHINE_CHECK);
+		}
+	}
+	mcgstl &= ~(1<<2);
+	wrmsr (MSR_IA32_MCG_STATUS,mcgstl, mcgsth);
+}
+
+/* Set up machine check reporting for processors with Intel style MCE */
+void __init intel_p6_mcheck_init(struct cpuinfo_x86 *c)
+{
+	u32 l, h;
+	int i;
+	
+	/* Check for MCE support */
+	if (!cpu_has(c, X86_FEATURE_MCE))
+		return;
+
+	/* Check for PPro style MCA */
+ 	if (!cpu_has(c, X86_FEATURE_MCA))
+		return;
+
+	/* Ok machine check is available */
+	machine_check_vector = intel_machine_check;
+	wmb();
+
+	printk (KERN_INFO "Intel machine check architecture supported.\n");
+	rdmsr (MSR_IA32_MCG_CAP, l, h);
+	if (l & (1<<8))	/* Control register present ? */
+		wrmsr(MSR_IA32_MCG_CTL, 0xffffffff, 0xffffffff);
+	nr_mce_banks = l & 0xff;
+
+	/* Don't enable bank 0 on intel P6 cores, it goes bang quickly. */
+	for (i=1; i<nr_mce_banks; i++) {
+		wrmsr (MSR_IA32_MC0_CTL+4*i, 0xffffffff, 0xffffffff);
+		wrmsr (MSR_IA32_MC0_STATUS+4*i, 0x0, 0x0);
+	}
+
+	set_in_cr4 (X86_CR4_MCE);
+	printk (KERN_INFO "Intel machine check reporting enabled on CPU#%d.\n",
+		smp_processor_id());
+}

arch/i386/kernel/cpu/mcheck/winchip.c

@@ -0,0 +1,37 @@
+/*
+ * IDT Winchip specific Machine Check Exception Reporting
+ * (C) Copyright 2002 Alan Cox <alan@redhat.com>
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+
+#include <asm/processor.h> 
+#include <asm/system.h>
+#include <asm/msr.h>
+
+#include "mce.h"
+
+/* Machine check handler for WinChip C6 */
+static fastcall void winchip_machine_check(struct pt_regs * regs, long error_code)
+{
+	printk(KERN_EMERG "CPU0: Machine Check Exception.\n");
+	add_taint(TAINT_MACHINE_CHECK);
+}
+
+/* Set up machine check reporting on the Winchip C6 series */
+void __init winchip_mcheck_init(struct cpuinfo_x86 *c)
+{
+	u32 lo, hi;
+	machine_check_vector = winchip_machine_check;
+	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");
+}