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authorStephane Eranian <eranian@hpl.hp.com>2006-12-07 02:14:11 +0100
committerAndi Kleen <andi@basil.nowhere.org>2006-12-07 02:14:11 +0100
commitee58fad51a2a767cb2567706ace967705233d881 (patch)
treeb87f182688a0ffb3b60f78637f391e69c59d1e59
parent7e95b593a1aeb6fe1d3904e799d23a45261f2c19 (diff)
[PATCH] x86-64: x86-64 add Intel BTS cpufeature bit and detection (take 2)
Here is a small patch for x86-64 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>
-rw-r--r--arch/x86_64/kernel/setup.c2
-rw-r--r--include/asm-x86_64/cpufeature.h2
2 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index 619af2e2fa26..a570c81c8316 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -838,6 +838,8 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c)
if (cpu_has_ds) {
unsigned int l1, l2;
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 --git a/include/asm-x86_64/cpufeature.h b/include/asm-x86_64/cpufeature.h
index d280384807ef..0b3c686139f1 100644
--- a/include/asm-x86_64/cpufeature.h
+++ b/include/asm-x86_64/cpufeature.h
@@ -69,6 +69,7 @@
#define X86_FEATURE_UP (3*32+8) /* SMP kernel running on UP */
#define X86_FEATURE_ARCH_PERFMON (3*32+9) /* Intel Architectural PerfMon */
#define X86_FEATURE_PEBS (3*32+10) /* Precise-Event Based Sampling */
+#define X86_FEATURE_BTS (3*32+11) /* Branch Trace Store */
/* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
#define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */
@@ -115,5 +116,6 @@
#define cpu_has_clflush boot_cpu_has(X86_FEATURE_CLFLSH)
#define cpu_has_ds boot_cpu_has(X86_FEATURE_DS)
#define cpu_has_pebs boot_cpu_has(X86_FEATURE_PEBS)
+#define cpu_has_bts boot_cpu_has(X86_FEATURE_BTS)
#endif /* __ASM_X8664_CPUFEATURE_H */