x86, cpu: Preset default tlb_flushall_shift on AMD

Run the mprotect.c microbenchmark on all our families >= K8 and preset
the flushall shift variable accordingly.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Link: http://lkml.kernel.org/r/1344272439-29080-5-git-send-email-bp@amd64.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index bcd200839c90..f7e98a2c0d12 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -737,6 +737,17 @@ static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 *c,
 }
 #endif
 
+static void __cpuinit cpu_set_tlb_flushall_shift(struct cpuinfo_x86 *c)
+{
+        if (!cpu_has_invlpg)
+                return;
+
+        tlb_flushall_shift = 5;
+
+        if (c->x86 <= 0x11)
+                tlb_flushall_shift = 4;
+}
+
 static void __cpuinit cpu_detect_tlb_amd(struct cpuinfo_x86 *c)
 {
         u32 ebx, eax, ecx, edx;
@@ -788,6 +799,8 @@ static void __cpuinit cpu_detect_tlb_amd(struct cpuinfo_x86 *c)
                 tlb_lli_2m[ENTRIES] = eax & mask;
 
         tlb_lli_4m[ENTRIES] = tlb_lli_2m[ENTRIES] >> 1;
+
+        cpu_set_tlb_flushall_shift(c);
 }
 
 static const struct cpu_dev __cpuinitconst amd_cpu_dev = {