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Diffstat (limited to 'arch/x86_64/kernel/setup.c')
-rw-r--r--arch/x86_64/kernel/setup.c21
1 files changed, 15 insertions, 6 deletions
diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index f12f266f3e9..af425a8049f 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -731,11 +731,8 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
/* Fix cpuid4 emulation for more */
num_cache_leaves = 3;
- /* When there is only one core no need to synchronize RDTSC */
- if (num_possible_cpus() == 1)
- set_bit(X86_FEATURE_SYNC_RDTSC, &c->x86_capability);
- else
- clear_bit(X86_FEATURE_SYNC_RDTSC, &c->x86_capability);
+ /* RDTSC can be speculated around */
+ clear_bit(X86_FEATURE_SYNC_RDTSC, &c->x86_capability);
}
static void __cpuinit detect_ht(struct cpuinfo_x86 *c)
@@ -834,6 +831,15 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c)
set_bit(X86_FEATURE_ARCH_PERFMON, &c->x86_capability);
}
+ if (cpu_has_ds) {
+ unsigned int l1, l2;
+ rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
+ if (!(l1 & (1<<11)))
+ set_bit(X86_FEATURE_BTS, c->x86_capability);
+ if (!(l1 & (1<<12)))
+ set_bit(X86_FEATURE_PEBS, c->x86_capability);
+ }
+
n = c->extended_cpuid_level;
if (n >= 0x80000008) {
unsigned eax = cpuid_eax(0x80000008);
@@ -853,7 +859,10 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c)
set_bit(X86_FEATURE_CONSTANT_TSC, &c->x86_capability);
if (c->x86 == 6)
set_bit(X86_FEATURE_REP_GOOD, &c->x86_capability);
- set_bit(X86_FEATURE_SYNC_RDTSC, &c->x86_capability);
+ if (c->x86 == 15)
+ set_bit(X86_FEATURE_SYNC_RDTSC, &c->x86_capability);
+ else
+ clear_bit(X86_FEATURE_SYNC_RDTSC, &c->x86_capability);
c->x86_max_cores = intel_num_cpu_cores(c);
srat_detect_node();