Messages in this thread Patch in this message | | | Date | Fri, 6 Oct 2006 06:14:51 -0700 | From | Stephane Eranian <> | Subject | [PATCH] i386 add X86_FEATURE_PEBS and detection |
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Hello,
Here is a patch (used by perfmon2) to detect the presence of the Precise Event Based Sampling (PEBS) feature for i386. The patch also adds the cpu_has_pebs macro.
IMPORTANT: you need to have the i386 X86_FEATURE_DS renaming patch applied first!
changelog: - adds X86_FEATURE_PEBS - adds cpu_has_pebs to test for X86_FEATURE_PEBS
signed-off-by: stephane eranian <eranian@hpl.hp.com>
diff --git a/arch/i386/kernel/cpu/intel.c b/arch/i386/kernel/cpu/intel.c index 94a95aa..798c2f6 100644 --- a/arch/i386/kernel/cpu/intel.c +++ b/arch/i386/kernel/cpu/intel.c @@ -195,8 +195,14 @@ #endif if ((c->x86 == 0xf && c->x86_model >= 0x03) || (c->x86 == 0x6 && c->x86_model >= 0x0e)) set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability); -} + if (cpu_has_ds) { + unsigned int l1; + rdmsr(MSR_IA32_MISC_ENABLE, l1, l2); + if (!(l1 & (1<<12))) + set_bit(X86_FEATURE_PEBS, c->x86_capability); + } +} static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 * c, unsigned int size) { --- a/include/asm-i386/cpufeature.h 2006-10-06 05:34:05.000000000 -0700 +++ b/include/asm-i386/cpufeature.h 2006-10-06 05:12:57.000000000 -0700 @@ -73,6 +73,7 @@ #define X86_FEATURE_UP (3*32+ 9) /* smp kernel running on up */ #define X86_FEATURE_FXSAVE_LEAK (3*32+10) /* FXSAVE leaks FOP/FIP/FOP */ #define X86_FEATURE_ARCH_PERFMON (3*32+11) /* Intel Architectural PerfMon */ +#define X86_FEATURE_PEBS (3*32+12) /* Precise-Event Based Sampling */ /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */ #define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */ @@ -135,6 +136,7 @@ #define cpu_has_pmm boot_cpu_has(X86_FEATURE_PMM) #define cpu_has_pmm_enabled boot_cpu_has(X86_FEATURE_PMM_EN) #define cpu_has_ds boot_cpu_has(X86_FEATURE_DS) +#define cpu_has_pebs boot_cpu_has(X86_FEATURE_PEBS) #endif /* __ASM_I386_CPUFEATURE_H */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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