k7.c

/*
 * Athlon specific Machine Check Exception Reporting
 * (C) Copyright 2002 Dave Jones <davej@redhat.com>
 */
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/smp.h>

#include <asm/processor.h>
#include <asm/system.h>
#include <asm/mce.h>
#include <asm/msr.h>

/* Machine Check Handler For AMD Athlon/Duron: */
static void k7_machine_check(struct pt_regs *regs, long error_code)
{
	u32 alow, ahigh, high, low;
	u32 mcgstl, mcgsth;
	int recover = 1;
	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)) {
			char misc[20];
			char addr[24];

			misc[0] = '\0';
			addr[0] = '\0';

			if (high & (1<<29))
				recover |= 1;
			if (high & (1<<25))
				recover |= 2;
			high &= ~(1<<31);

			if (high & (1<<27)) {
				rdmsr(MSR_IA32_MC0_MISC+i*4, alow, ahigh);
				snprintf(misc, 20, "[%08x%08x]", ahigh, alow);
			}
			if (high & (1<<26)) {
				rdmsr(MSR_IA32_MC0_ADDR+i*4, alow, ahigh);
				snprintf(addr, 24, " at %08x%08x", ahigh, alow);
			}

			printk(KERN_EMERG "CPU %d: Bank %d: %08x%08x%s%s\n",
				smp_processor_id(), i, high, low, misc, addr);

			/* 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 amd_mcheck_init(struct cpuinfo_x86 *c)
{
	u32 l, h;
	int i;

	if (!cpu_has(c, X86_FEATURE_MCE))
		return;

	machine_check_vector = k7_machine_check;
	/* Make sure the vector pointer is visible before we enable MCEs: */
	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 K7 Athlons cause spurious MCEs when its enabled:
	 */
	if (boot_cpu_data.x86 == 6) {
		wrmsr(MSR_IA32_MC0_STATUS, 0x0, 0x0);
		i = 1;
	} else
		i = 0;

	for (; 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());
}