x86: implement support to synchronize RDTSC through MFENCE on AMD CPUs

According to AMD RDTSC can be synchronized through MFENCE.
Implement the necessary CPUID bit for that.

Cc: andreas.herrmann3@amd.com
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Andi Kleen
2008-01-30 13:32:37 +01:00
committed by Ingo Molnar
parent 27efeb6771
commit de4218634e
3 changed files with 6 additions and 2 deletions

View File

@ -301,6 +301,9 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
/* K6s reports MCEs but don't actually have all the MSRs */
if (c->x86 < 6)
clear_bit(X86_FEATURE_MCE, c->x86_capability);
if (cpu_has_xmm)
set_bit(X86_FEATURE_MFENCE_RDTSC, c->x86_capability);
}
static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 * c, unsigned int size)