From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756304Ab2GBUkw (ORCPT ); Mon, 2 Jul 2012 16:40:52 -0400 Received: from mga01.intel.com ([192.55.52.88]:60318 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754404Ab2GBUkt (ORCPT ); Mon, 2 Jul 2012 16:40:49 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="172661969" From: Andi Kleen To: a.p.zijlstra@chello.nl Cc: x86@kernel.org, eranian@google.com, linux-kernel@vger.kernel.org, Andi Kleen Subject: [PATCH 4/5] perf, x86: check ucode before disabling PEBS on SandyBridge v4 Date: Mon, 2 Jul 2012 13:40:45 -0700 Message-Id: <1341261646-3171-5-git-send-email-andi@firstfloor.org> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <1341261646-3171-1-git-send-email-andi@firstfloor.org> References: <1341261646-3171-1-git-send-email-andi@firstfloor.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stephane Eranian [AK: Updated version of Stephane's patch with various changes. This version now relies on the global microcode update that has been implemented in another patch. It also assumes that the BIOS puts the same microcode version on every CPU.] This patch checks the microcode version before disabling PEBS on SandyBridge model 42 (desktop, mobile), and 45 (SNB-EP). PEBS was disabled for both models due to an erratum. A workaround is implemented by micro-code specific to different models. This patch checks the microcode version and disables PEBS support only if the needed fixes are not available. The check is done each time a PEBS event is created and NOT at boot time because the micro-code update may only be done after the kernel has booted. Go to downloadcenter.intel.com to download microcode updates. Need microcode update 6/6/2012 or later. v2: Was Stephane's old revision v3: Use boot_cpu_data.microcode (H. Peter Anvin) v4: Various updates. Now improved model check that handles both C1 and C2 steppings. Signed-off-by: Stephane Eranian Signed-off-by: Andi Kleen --- arch/x86/kernel/cpu/perf_event_intel.c | 41 ++++++++++++++++++++++++------- 1 files changed, 31 insertions(+), 10 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 2c045c8..e727e1a 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -13,6 +13,7 @@ #include #include +#include #include "perf_event.h" @@ -1392,6 +1393,29 @@ static void intel_pebs_aliases_snb(struct perf_event *event) } } +static int check_pebs_quirks(void) +{ + /* With different CPUs boot_cpu_data ucode will be 0 */ + int model = boot_cpu_data.x86_model; + int ucode = boot_cpu_data.microcode; + int stepping = boot_cpu_data.x86_mask; + + /* do not have PEBS to begin with */ + if (!x86_pmu.pebs) + return 0; + + /* + * check ucode version for SNB, SNB-EP + */ + if ((model == 42 && ucode < 0x28) || + (model == 45 && ucode < 0x70c) || + (model == 45 && stepping == 6 && ucode < 0x618)) { + pr_warn_once("SandyBridge PEBS unavailable due to CPU erratum, update microcode\n"); + return -ENOTSUPP; + } + return 0; +} + static int intel_pmu_hw_config(struct perf_event *event) { int ret = x86_pmu_hw_config(event); @@ -1399,8 +1423,13 @@ static int intel_pmu_hw_config(struct perf_event *event) if (ret) return ret; - if (event->attr.precise_ip && x86_pmu.pebs_aliases) - x86_pmu.pebs_aliases(event); + if (event->attr.precise_ip) { + if (check_pebs_quirks()) + return -ENOTSUPP; + + if (x86_pmu.pebs_aliases) + x86_pmu.pebs_aliases(event); + } if (intel_pmu_needs_lbr_smpl(event)) { ret = intel_pmu_setup_lbr_filter(event); @@ -1735,13 +1764,6 @@ static __init void intel_clovertown_quirk(void) x86_pmu.pebs_constraints = NULL; } -static __init void intel_sandybridge_quirk(void) -{ - printk(KERN_WARNING "PEBS disabled due to CPU errata.\n"); - x86_pmu.pebs = 0; - x86_pmu.pebs_constraints = NULL; -} - static const struct { int id; char *name; } intel_arch_events_map[] __initconst = { { PERF_COUNT_HW_CPU_CYCLES, "cpu cycles" }, { PERF_COUNT_HW_INSTRUCTIONS, "instructions" }, @@ -1935,7 +1957,6 @@ __init int intel_pmu_init(void) case 42: /* SandyBridge */ case 45: /* SandyBridge, "Romely-EP" */ - x86_add_quirk(intel_sandybridge_quirk); memcpy(hw_cache_event_ids, snb_hw_cache_event_ids, sizeof(hw_cache_event_ids)); -- 1.7.7.6