root/arch/x86/kernel/cpu/mcheck/p6.c

DEFINITIONS

1. intel_machine_check
2. intel_p6_mcheck_init

/*
 * 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/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 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)) {
                        char misc[20];
                        char addr[24];
                        misc[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);
                }
        }

        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 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;

        /*
         * Following the example in IA-32 SDM Vol 3:
         * - MC0_CTL should not be written
         * - Status registers on all banks should be cleared on reset
         */
        for (i = 1; i < nr_mce_banks; i++)
                wrmsr(MSR_IA32_MC0_CTL+4*i, 0xffffffff, 0xffffffff);

        for (i = 0; i < nr_mce_banks; i++)
                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());
}