Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  * P6 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/system.h>
 13 #include <asm/mce.h>
 14 #include <asm/msr.h>
 15 
 16 /* Machine Check Handler For PII/PIII */
 17 static void intel_machine_check(struct pt_regs *regs, long error_code)
 18 {
 19         u32 alow, ahigh, high, low;
 20         u32 mcgstl, mcgsth;
 21         int recover = 1;
 22         int i;
 23 
 24         rdmsr(MSR_IA32_MCG_STATUS, mcgstl, mcgsth);
 25         if (mcgstl & (1<<0))    /* Recoverable ? */
 26                 recover = 0;
 27 
 28         printk(KERN_EMERG "CPU %d: Machine Check Exception: %08x%08x\n",
 29                 smp_processor_id(), mcgsth, mcgstl);
 30 
 31         for (i = 0; i < nr_mce_banks; i++) {
 32                 rdmsr(MSR_IA32_MC0_STATUS+i*4, low, high);
 33                 if (high & (1<<31)) {
 34                         char misc[20];
 35                         char addr[24];
 36 
 37                         misc[0] = '\0';
 38                         addr[0] = '\0';
 39 
 40                         if (high & (1<<29))
 41                                 recover |= 1;
 42                         if (high & (1<<25))
 43                                 recover |= 2;
 44                         high &= ~(1<<31);
 45 
 46                         if (high & (1<<27)) {
 47                                 rdmsr(MSR_IA32_MC0_MISC+i*4, alow, ahigh);
 48                                 snprintf(misc, 20, "[%08x%08x]", ahigh, alow);
 49                         }
 50                         if (high & (1<<26)) {
 51                                 rdmsr(MSR_IA32_MC0_ADDR+i*4, alow, ahigh);
 52                                 snprintf(addr, 24, " at %08x%08x", ahigh, alow);
 53                         }
 54 
 55                         printk(KERN_EMERG "CPU %d: Bank %d: %08x%08x%s%s\n",
 56                                 smp_processor_id(), i, high, low, misc, addr);
 57                 }
 58         }
 59 
 60         if (recover & 2)
 61                 panic("CPU context corrupt");
 62         if (recover & 1)
 63                 panic("Unable to continue");
 64 
 65         printk(KERN_EMERG "Attempting to continue.\n");
 66         /*
 67          * Do not clear the MSR_IA32_MCi_STATUS if the error is not
 68          * recoverable/continuable.This will allow BIOS to look at the MSRs
 69          * for errors if the OS could not log the error:
 70          */
 71         for (i = 0; i < nr_mce_banks; i++) {
 72                 unsigned int msr;
 73 
 74                 msr = MSR_IA32_MC0_STATUS+i*4;
 75                 rdmsr(msr, low, high);
 76                 if (high & (1<<31)) {
 77                         /* Clear it: */
 78                         wrmsr(msr, 0UL, 0UL);
 79                         /* Serialize: */
 80                         wmb();
 81                         add_taint(TAINT_MACHINE_CHECK);
 82                 }
 83         }
 84         mcgstl &= ~(1<<2);
 85         wrmsr(MSR_IA32_MCG_STATUS, mcgstl, mcgsth);
 86 }
 87 
 88 /* Set up machine check reporting for processors with Intel style MCE: */
 89 void intel_p6_mcheck_init(struct cpuinfo_x86 *c)
 90 {
 91         u32 l, h;
 92         int i;
 93 
 94         /* Check for MCE support */
 95         if (!cpu_has(c, X86_FEATURE_MCE))
 96                 return;
 97 
 98         /* Check for PPro style MCA */
 99         if (!cpu_has(c, X86_FEATURE_MCA))
100                 return;
101 
102         /* Ok machine check is available */
103         machine_check_vector = intel_machine_check;
104         /* Make sure the vector pointer is visible before we enable MCEs: */
105         wmb();
106 
107         printk(KERN_INFO "Intel machine check architecture supported.\n");
108         rdmsr(MSR_IA32_MCG_CAP, l, h);
109         if (l & (1<<8)) /* Control register present ? */
110                 wrmsr(MSR_IA32_MCG_CTL, 0xffffffff, 0xffffffff);
111         nr_mce_banks = l & 0xff;
112 
113         /*
114          * Following the example in IA-32 SDM Vol 3:
115          * - MC0_CTL should not be written
116          * - Status registers on all banks should be cleared on reset
117          */
118         for (i = 1; i < nr_mce_banks; i++)
119                 wrmsr(MSR_IA32_MC0_CTL+4*i, 0xffffffff, 0xffffffff);
120 
121         for (i = 0; i < nr_mce_banks; i++)
122                 wrmsr(MSR_IA32_MC0_STATUS+4*i, 0x0, 0x0);
123 
124         set_in_cr4(X86_CR4_MCE);
125         printk(KERN_INFO "Intel machine check reporting enabled on CPU#%d.\n",
126                 smp_processor_id());
127 }
128 
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