2.4.13

 arch

 i386

 kernel

diff -u --recursive --new-file v2.4.12/linux/arch/i386/kernel/bluesmoke.c linux/arch/i386/kernel/bluesmoke.c
--- v2.4.12/linux/arch/i386/kernel/bluesmoke.c   Sun Sep 23 11:40:55 2001
+++ linux/arch/i386/kernel/bluesmoke.c   Thu Oct 11 09:04:57 2001
@@ -6,6 +6,8 @@
 #include <asm/processor.h> 
 #include <asm/msr.h>
 
+static int mce_disabled __initdata = 0;
+
 /*
  *   Machine Check Handler For PII/PIII
  */
@@ -111,7 +113,7 @@
  *   Set up machine check reporting for Intel processors
  */
 
-void __init intel_mcheck_init(struct cpuinfo_x86 *c)
+static void __init intel_mcheck_init(struct cpuinfo_x86 *c)
 {
    u32 l, h;
    int i;
@@ -130,6 +132,9 @@
    
    if(c->x86 == 5)
    {
+      /* Default P5 to off as its often misconnected */
+      if(mce_disabled != -1)
+         return;
       machine_check_vector = pentium_machine_check;
       wmb();
       /* Read registers before enabling */
@@ -137,11 +142,8 @@
       rdmsr(MSR_IA32_P5_MC_TYPE, l, h);
       if(done==0)
          printk(KERN_INFO "Intel old style machine check architecture supported.\n");
-      /* Enable MCE */      
-      __asm__ __volatile__ (
-         "movl %%cr4, %%eax\n\t"
-         "orl $0x40, %%eax\n\t"
-         "movl %%eax, %%cr4\n\t" : : : "eax");
+       /* Enable MCE */
+      set_in_cr4(X86_CR4_MCE);
       printk(KERN_INFO "Intel old style machine check reporting enabled on CPU#%d.\n", smp_processor_id());
       return;
    }
@@ -195,10 +197,7 @@
    lo|= (1<<2);   /* Enable EIERRINT (int 18 MCE) */
    lo&= ~(1<<4);   /* Enable MCE */
    wrmsr(MSR_IDT_FCR1, lo, hi);
-   __asm__ __volatile__ (
-      "movl %%cr4, %%eax\n\t"
-      "orl $0x40, %%eax\n\t"
-      "movl %%eax, %%cr4\n\t" : : : "eax");
+   set_in_cr4(X86_CR4_MCE);
    printk(KERN_INFO "Winchip machine check reporting enabled on CPU#%d.\n", smp_processor_id());
 }
 
@@ -208,11 +207,10 @@
  */
 
 
-static int mce_disabled = 0;
 
 void __init mcheck_init(struct cpuinfo_x86 *c)
 {
-   if(mce_disabled)
+   if(mce_disabled==1)
       return;
       
    switch(c->x86_vendor)
@@ -230,6 +228,8 @@
       case X86_VENDOR_CENTAUR:
          winchip_mcheck_init(c);
          break;
+      default:
+         break;
    }
 }
 
@@ -238,4 +238,12 @@
    mce_disabled = 1;
    return 0;
 }
+
+static int __init mcheck_enable(char *str)
+{
+   mce_disabled = -1;
+   return 0;
+}
+
 __setup("nomce", mcheck_disable);
+__setup("mce", mcheck_enable);