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/init.h>
   9 #include <linux/smp.h>
  10
  11 #include <asm/processor.h>
  12 #include <asm/mce.h>
  13 #include <asm/msr.h>
  14
  15 /* By default disabled */
  16 int mce_p5_enabled __read_mostly;
  17
  18 /* Machine check handler for Pentium class Intel CPUs: */
  19 static void pentium_machine_check(struct pt_regs *regs, long error_code)
  20 {
  21         u32 loaddr, hi, lotype;
  22
  23         rdmsr(MSR_IA32_P5_MC_ADDR, loaddr, hi);
  24         rdmsr(MSR_IA32_P5_MC_TYPE, lotype, hi);
  25
  26         printk(KERN_EMERG
  27                 "CPU#%d: Machine Check Exception:  0x%8X (type 0x%8X).\n",
  28                 smp_processor_id(), loaddr, lotype);
  29
  30         if (lotype & (1<<5)) {
  31                 printk(KERN_EMERG
  32                         "CPU#%d: Possible thermal failure (CPU on fire ?).\n",
  33                         smp_processor_id());
  34         }
  35
  36         add_taint(TAINT_MACHINE_CHECK);
  37 }
  38
  39 /* Set up machine check reporting for processors with Intel style MCE: */
  40 void intel_p5_mcheck_init(struct cpuinfo_x86 *c)
  41 {
  42         u32 l, h;
  43
  44         /* Default P5 to off as its often misconnected: */
  45         if (!mce_p5_enabled)
  46                 return;
  47
  48         /* Check for MCE support: */
  49         if (!cpu_has(c, X86_FEATURE_MCE))
  50                 return;
  51
  52         machine_check_vector = pentium_machine_check;
  53         /* Make sure the vector pointer is visible before we enable MCEs: */
  54         wmb();
  55
  56         /* Read registers before enabling: */
  57         rdmsr(MSR_IA32_P5_MC_ADDR, l, h);
  58         rdmsr(MSR_IA32_P5_MC_TYPE, l, h);
  59         printk(KERN_INFO
  60                "Intel old style machine check architecture supported.\n");
  61
  62         /* Enable MCE: */
  63         set_in_cr4(X86_CR4_MCE);
  64         printk(KERN_INFO
  65                "Intel old style machine check reporting enabled on CPU#%d.\n",
  66                smp_processor_id());
  67 }