x86: Stop MCEs and NMIs during code patching
[linux-2.6.git] / arch / i386 / kernel / cpu / mcheck / mce.c
1 /*
2  * mce.c - x86 Machine Check Exception Reporting
3  * (c) 2002 Alan Cox <alan@redhat.com>, Dave Jones <davej@codemonkey.org.uk>
4  */
5
6 #include <linux/init.h>
7 #include <linux/types.h>
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/smp.h>
11 #include <linux/thread_info.h>
12
13 #include <asm/processor.h> 
14 #include <asm/system.h>
15 #include <asm/mce.h>
16
17 #include "mce.h"
18
19 int mce_disabled = 0;
20 int nr_mce_banks;
21
22 EXPORT_SYMBOL_GPL(nr_mce_banks);        /* non-fatal.o */
23
24 /* Handle unconfigured int18 (should never happen) */
25 static fastcall void unexpected_machine_check(struct pt_regs * regs, long error_code)
26 {       
27         printk(KERN_ERR "CPU#%d: Unexpected int18 (Machine Check).\n", smp_processor_id());
28 }
29
30 /* Call the installed machine check handler for this CPU setup. */
31 void fastcall (*machine_check_vector)(struct pt_regs *, long error_code) = unexpected_machine_check;
32
33 /* This has to be run for each processor */
34 void mcheck_init(struct cpuinfo_x86 *c)
35 {
36         if (mce_disabled==1)
37                 return;
38
39         switch (c->x86_vendor) {
40                 case X86_VENDOR_AMD:
41                         amd_mcheck_init(c);
42                         break;
43
44                 case X86_VENDOR_INTEL:
45                         if (c->x86==5)
46                                 intel_p5_mcheck_init(c);
47                         if (c->x86==6)
48                                 intel_p6_mcheck_init(c);
49                         if (c->x86==15)
50                                 intel_p4_mcheck_init(c);
51                         break;
52
53                 case X86_VENDOR_CENTAUR:
54                         if (c->x86==5)
55                                 winchip_mcheck_init(c);
56                         break;
57
58                 default:
59                         break;
60         }
61 }
62
63 static unsigned long old_cr4 __initdata;
64
65 void __init stop_mce(void)
66 {
67         old_cr4 = read_cr4();
68         clear_in_cr4(X86_CR4_MCE);
69 }
70
71 void __init restart_mce(void)
72 {
73         if (old_cr4 & X86_CR4_MCE)
74                 set_in_cr4(X86_CR4_MCE);
75 }
76
77 static int __init mcheck_disable(char *str)
78 {
79         mce_disabled = 1;
80         return 1;
81 }
82
83 static int __init mcheck_enable(char *str)
84 {
85         mce_disabled = -1;
86         return 1;
87 }
88
89 __setup("nomce", mcheck_disable);
90 __setup("mce", mcheck_enable);