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[PATCH] i386: i386 add Intel BTS cpufeature bit and detection (take 2)

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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.

changelog:
	- add CPU_FEATURE_BTS
	- add Branch Trace Store detection

signed-off-by: stephane eranian <eranian@hpl.hp.com>

Signed-off-by: Andi Kleen <ak@suse.de>
This commit is contained in:
Stephane Eranian 2006-12-07 02:14:11 +01:00 committed by Andi Kleen
parent ee58fad51a
commit 538f188e03
2 changed files with 4 additions and 0 deletions
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2
arch/i386/kernel/cpu/intel.c
View File

@ -199,6 +199,8 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c)
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);
}

2
include/asm-i386/cpufeature.h
View File

@ -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 */