Messages in this thread Patch in this message |  | | Date | Thu, 16 Nov 2006 06:22:25 -0800 | From | Stephane Eranian <> | Subject | [PATCH] i386 add Intel BTS cpufeature bit and detection (take 2) |
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Andi,
Here is a small patch for i386 which adds a cpufeature flag and detection code for Intel's Branch Trace Store (BTS) feature. This feature can be found on Intel P4 and Core 2 processors among others. It can also be used by perfmon.
The patch is relative to 2.6.19-rc5-git7 + x86_64-2.6.19-rc5-git7-061116-2
changelog: - add CPU_FEATURE_BTS - add Branch Trace Store detection
signed-off-by: stephane eranian <eranian@hpl.hp.com>
diff --exclude=.git -urNp linux-2.6.19-rc5-git7-ak.orig/arch/i386/kernel/cpu/intel.c linux-2.6.19-rc5-git7-ak/arch/i386/kernel/cpu/intel.c --- linux-2.6.19-rc5-git7-ak.orig/arch/i386/kernel/cpu/intel.c 2006-11-16 05:15:39.000000000 -0800 +++ linux-2.6.19-rc5-git7-ak/arch/i386/kernel/cpu/intel.c 2006-11-16 05:49:11.000000000 -0800 @@ -199,6 +199,8 @@ static void __cpuinit init_intel(struct if (cpu_has_ds) { unsigned int l1; 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); } diff --exclude=.git -urNp linux-2.6.19-rc5-git7-ak.orig/include/asm-i386/cpufeature.h linux-2.6.19-rc5-git7-ak/include/asm-i386/cpufeature.h --- linux-2.6.19-rc5-git7-ak.orig/include/asm-i386/cpufeature.h 2006-11-16 05:15:39.000000000 -0800 +++ linux-2.6.19-rc5-git7-ak/include/asm-i386/cpufeature.h 2006-11-16 05:48:52.000000000 -0800 @@ -74,6 +74,7 @@ #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 */ +#define X86_FEATURE_BTS (3*32+13) /* Branch Trace Store */ /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */ #define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */ @@ -138,6 +139,7 @@ #define cpu_has_ds boot_cpu_has(X86_FEATURE_DS) #define cpu_has_pebs boot_cpu_has(X86_FEATURE_PEBS) #define cpu_has_clflush boot_cpu_has(X86_FEATURE_CLFLSH) +#define cpu_has_bts boot_cpu_has(X86_FEATURE_BTS) #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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