x86, cpu: Fix regression in AMD errata checking code

A bug in the family-model-stepping matching code caused the presence of
errata to go undetected when OSVW was not used. This causes hangs on
some K8 systems because the E400 workaround is not enabled.

Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
LKML-Reference: <1282141190-930137-1-git-send-email-hans.rosenfeld@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 60a57b13082..ba5f62f45f0 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -669,7 +669,7 @@ bool cpu_has_amd_erratum(const int *erratum)
         }
 
         /* OSVW unavailable or ID unknown, match family-model-stepping range */
-        ms = (cpu->x86_model << 8) | cpu->x86_mask;
+        ms = (cpu->x86_model << 4) | cpu->x86_mask;
         while ((range = *erratum++))
                 if ((cpu->x86 == AMD_MODEL_RANGE_FAMILY(range)) &&
                     (ms >= AMD_MODEL_RANGE_START(range)) &&