From 36b2a8d5aff4cb3ee83d5e40447a8f073bcfe2fb Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Thu, 7 Dec 2006 02:14:01 +0100 Subject: [PATCH] x86-64: add X86_FEATURE_PEBS and detection Here is a patch (used by perfmon2) to detect the presence of the Precise Event Based Sampling (PEBS) feature for Intel 64-bit processors. The patch also adds the cpu_has_pebs macro. changelog: - adds X86_FEATURE_PEBS - adds cpu_has_pebs to test for X86_FEATURE_PEBS Signed-off-by: stephane eranian Signed-off-by: Andi Kleen --- arch/x86_64/kernel/setup.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/x86_64/kernel/setup.c') diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c index fc944b5e8f4..619af2e2fa2 100644 --- a/arch/x86_64/kernel/setup.c +++ b/arch/x86_64/kernel/setup.c @@ -835,6 +835,13 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c) set_bit(X86_FEATURE_ARCH_PERFMON, &c->x86_capability); } + if (cpu_has_ds) { + unsigned int l1, l2; + rdmsr(MSR_IA32_MISC_ENABLE, l1, l2); + if (!(l1 & (1<<12))) + set_bit(X86_FEATURE_PEBS, c->x86_capability); + } + n = c->extended_cpuid_level; if (n >= 0x80000008) { unsigned eax = cpuid_eax(0x80000008); -- cgit v1.2.3