LXR linux/arch/x86/kernel/cpu/mce/p5.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * P5 specific Machine Check Exception Reporting
   4 * (C) Copyright 2002 Alan Cox <alan@lxorguk.ukuu.org.uk>
   5 */
   6#include <linux/interrupt.h>
   7#include <linux/kernel.h>
   8#include <linux/types.h>
   9#include <linux/smp.h>
  10
  11#include <asm/processor.h>
  12#include <asm/traps.h>
  13#include <asm/tlbflush.h>
  14#include <asm/mce.h>
  15#include <asm/msr.h>
  16
  17#include "internal.h"
  18
  19/* By default disabled */
  20int mce_p5_enabled __read_mostly;
  21
  22/* Machine check handler for Pentium class Intel CPUs: */
  23static void pentium_machine_check(struct pt_regs *regs, long error_code)
  24{
  25        u32 loaddr, hi, lotype;
  26
  27        ist_enter(regs);
  28
  29        rdmsr(MSR_IA32_P5_MC_ADDR, loaddr, hi);
  30        rdmsr(MSR_IA32_P5_MC_TYPE, lotype, hi);
  31
  32        pr_emerg("CPU#%d: Machine Check Exception:  0x%8X (type 0x%8X).\n",
  33                 smp_processor_id(), loaddr, lotype);
  34
  35        if (lotype & (1<<5)) {
  36                pr_emerg("CPU#%d: Possible thermal failure (CPU on fire ?).\n",
  37                         smp_processor_id());
  38        }
  39
  40        add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
  41
  42        ist_exit(regs);
  43}
  44
  45/* Set up machine check reporting for processors with Intel style MCE: */
  46void intel_p5_mcheck_init(struct cpuinfo_x86 *c)
  47{
  48        u32 l, h;
  49
  50        /* Default P5 to off as its often misconnected: */
  51        if (!mce_p5_enabled)
  52                return;
  53
  54        /* Check for MCE support: */
  55        if (!cpu_has(c, X86_FEATURE_MCE))
  56                return;
  57
  58        machine_check_vector = pentium_machine_check;
  59        /* Make sure the vector pointer is visible before we enable MCEs: */
  60        wmb();
  61
  62        /* Read registers before enabling: */
  63        rdmsr(MSR_IA32_P5_MC_ADDR, l, h);
  64        rdmsr(MSR_IA32_P5_MC_TYPE, l, h);
  65        pr_info("Intel old style machine check architecture supported.\n");
  66
  67        /* Enable MCE: */
  68        cr4_set_bits(X86_CR4_MCE);
  69        pr_info("Intel old style machine check reporting enabled on CPU#%d.\n",
  70                smp_processor_id());
  71}
  72