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-rw-r--r--arch/i386/kernel/cpu/intel.c4
-rw-r--r--include/asm-i386/cpufeature.h1
-rw-r--r--include/asm-i386/tsc.h4
3 files changed, 4 insertions, 5 deletions
diff --git a/arch/i386/kernel/cpu/intel.c b/arch/i386/kernel/cpu/intel.c
index 56fe2658495..dc4e08147b1 100644
--- a/arch/i386/kernel/cpu/intel.c
+++ b/arch/i386/kernel/cpu/intel.c
@@ -188,8 +188,10 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c)
}
#endif
- if (c->x86 == 15)
+ if (c->x86 == 15) {
set_bit(X86_FEATURE_P4, c->x86_capability);
+ set_bit(X86_FEATURE_SYNC_RDTSC, c->x86_capability);
+ }
if (c->x86 == 6)
set_bit(X86_FEATURE_P3, c->x86_capability);
if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
diff --git a/include/asm-i386/cpufeature.h b/include/asm-i386/cpufeature.h
index 20e849ae6dd..b8a3a5a85fd 100644
--- a/include/asm-i386/cpufeature.h
+++ b/include/asm-i386/cpufeature.h
@@ -79,6 +79,7 @@
#define X86_FEATURE_PEBS (3*32+12) /* Precise-Event Based Sampling */
#define X86_FEATURE_BTS (3*32+13) /* Branch Trace Store */
#define X86_FEATURE_LAPIC_TIMER_BROKEN (3*32+ 14) /* lapic timer broken in C1 */
+#define X86_FEATURE_SYNC_RDTSC (3*32+15) /* RDTSC synchronizes the CPU */
/* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
#define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */
diff --git a/include/asm-i386/tsc.h b/include/asm-i386/tsc.h
index 346976632e1..0181f9df753 100644
--- a/include/asm-i386/tsc.h
+++ b/include/asm-i386/tsc.h
@@ -35,7 +35,6 @@ static inline cycles_t get_cycles(void)
static __always_inline cycles_t get_cycles_sync(void)
{
unsigned long long ret;
-#ifdef X86_FEATURE_SYNC_RDTSC
unsigned eax;
/*
@@ -44,9 +43,6 @@ static __always_inline cycles_t get_cycles_sync(void)
*/
alternative_io("cpuid", ASM_NOP2, X86_FEATURE_SYNC_RDTSC,
"=a" (eax), "0" (1) : "ebx","ecx","edx","memory");
-#else
- sync_core();
-#endif
rdtscll(ret);
return ret;