i386: Clear MCE flag on AMD K6

It reports machine check capability in CPUID, but doesn't actually
implement all the necessary MSRs of the standard Intel machine
check architecture.

This fixes a boot failure on K6s recently introduced.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/i386/kernel/cpu/amd.c b/arch/i386/kernel/cpu/amd.c
index 4fec702afd7e..6f47eeeb93ea 100644
--- a/arch/i386/kernel/cpu/amd.c
+++ b/arch/i386/kernel/cpu/amd.c
@@ -280,6 +280,10 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
 
         if (c->x86 == 0x10 && !force_mwait)
                 clear_bit(X86_FEATURE_MWAIT, c->x86_capability);
+
+        /* K6s reports MCEs but don't actually have all the MSRs */
+        if (c->x86 < 6)
+                clear_bit(X86_FEATURE_MCE, c->x86_capability);
 }
 
 static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 * c, unsigned int size)