arch/x86/kernel/cpu/mcheck/p5.c

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