diff options
Diffstat (limited to 'arch/x86_64/kernel/setup.c')
| -rw-r--r-- | arch/x86_64/kernel/setup.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c index f12f266f3e98..af425a8049fb 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(); |