From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932092AbWJFJKW (ORCPT ); Fri, 6 Oct 2006 05:10:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932106AbWJFJKV (ORCPT ); Fri, 6 Oct 2006 05:10:21 -0400 Received: from madara.hpl.hp.com ([192.6.19.124]:56775 "EHLO madara.hpl.hp.com") by vger.kernel.org with ESMTP id S932092AbWJFJKV (ORCPT ); Fri, 6 Oct 2006 05:10:21 -0400 Date: Fri, 6 Oct 2006 02:10:06 -0700 From: Stephane Eranian To: linux-kernel@vger.kernel.org Cc: ak@suse.de, Stephane Eranian Subject: [PATCH] add X86_FEATURE_PEBS and detection Message-ID: <20061006091006.GD8793@frankl.hpl.hp.com> Reply-To: eranian@hpl.hp.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.1i Organisation: HP Labs Palo Alto Address: HP Labs, 1U-17, 1501 Page Mill road, Palo Alto, CA 94304, USA. E-mail: eranian@hpl.hp.com X-HPL-MailScanner: Found to be clean X-HPL-MailScanner-From: eranian@hpl.hp.com Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello, 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. IMPORTANT: you need to have the 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 --- a/arch/x86_64/kernel/setup.c +++ b/arch/x86_64/kernel/setup.c @@ -835,6 +835,13 @@ static void __cpuinit init_intel(struct 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); --- a/include/asm-x86_64/cpufeature.h +++ b/include/asm-x86_64/cpufeature.h @@ -68,6 +68,7 @@ #define X86_FEATURE_FXSAVE_LEAK (3*32+7) /* FIP/FOP/FDP leaks through FXSAVE */ #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 */ /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */ #define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */ @@ -113,5 +114,6 @@ #define cpu_has_centaur_mcr 0 #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) #endif /* __ASM_X8664_CPUFEATURE_H */