From 3aefbe0746580a710d4392a884ac1e4aac7c728f Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 2 May 2007 19:27:20 +0200 Subject: [PATCH] i386: Implement X86_FEATURE_SYNC_RDTSC on i386 Syncs up with x86-64. Signed-off-by: Andi Kleen --- arch/i386/kernel/cpu/intel.c | 4 +++- include/asm-i386/cpufeature.h | 1 + include/asm-i386/tsc.h | 4 ---- 3 files changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/i386/kernel/cpu/intel.c b/arch/i386/kernel/cpu/intel.c index 56fe26584957..dc4e08147b1f 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 20e849ae6ddc..b8a3a5a85fd3 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 346976632e15..0181f9df7539 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; -- cgit v1.2.3-59-g8ed1b