From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BCD49ECAAD2 for ; Mon, 29 Aug 2022 10:15:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229898AbiH2KPQ (ORCPT ); Mon, 29 Aug 2022 06:15:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229743AbiH2KOy (ORCPT ); Mon, 29 Aug 2022 06:14:54 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5F9126F7 for ; Mon, 29 Aug 2022 03:14:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=cjwMj5/XK3Arj3+DPDxgPLyq06v8ipOyphQTAJ1oEvk=; b=J9FKQjfLSa3gkKEh5/6FMIOwYh olQqOGNnjxr0fBB1tSswORAa+uMxiqB7kQnBWK1iO119KCY9W2l29Ipz5bNv65Nrj6mT0COVg9mNW 2UvMW282KntYrhZ7W5MGkzXEvwIvM1Wo0DIT79Y03O3QSJDKZUC4Wc/WKzdGnJoCGrMf2BvNFf3TJ B5zqtfTZUIqcD8aetotki/FzeU4klgBZ/oluJi2OaV0eECddys/toZt9m4PLYbycmFy2g69YhtIa6 ALzomFgRK2QmF6vM/FJCiuq8nx87KqUK+EqhoXUlBebku72rJivkOObQKwU5cYjCXftlesV4Oa48A 6hpJv0sQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1oSbn1-003053-Nd; Mon, 29 Aug 2022 10:14:43 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id D505B300750; Mon, 29 Aug 2022 12:14:41 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 8FB9F207296FB; Mon, 29 Aug 2022 12:14:41 +0200 (CEST) Message-ID: <20220829101321.839502514@infradead.org> User-Agent: quilt/0.66 Date: Mon, 29 Aug 2022 12:10:06 +0200 From: Peter Zijlstra To: x86@kernel.org, kan.liang@linux.intel.com, eranian@google.com, ravi.bangoria@amd.com Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org Subject: [PATCH v2 7/9] perf/x86/p4: Remove perfctr_second_write quirk References: <20220829100959.917169441@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now that we have a x86_pmu::set_period() method, use it to remove the perfctr_second_write quirk from the generic code. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/events/core.c | 12 +----------- arch/x86/events/intel/p4.c | 37 +++++++++++++++++++++++++++---------- arch/x86/events/perf_event.h | 2 +- 3 files changed, 29 insertions(+), 22 deletions(-) --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -1356,7 +1356,7 @@ static void x86_pmu_enable(struct pmu *p static_call(x86_pmu_enable_all)(added); } -static DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left); +DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left); /* * Set the next IRQ period, based on the hwc->period_left value. @@ -1416,16 +1416,6 @@ int x86_perf_event_set_period(struct per if (is_counter_pair(hwc)) wrmsrl(x86_pmu_event_addr(idx + 1), 0xffff); - /* - * Due to erratum on certan cpu we need - * a second write to be sure the register - * is updated properly - */ - if (x86_pmu.perfctr_second_write) { - wrmsrl(hwc->event_base, - (u64)(-left) & x86_pmu.cntval_mask); - } - perf_event_update_userpage(event); return ret; --- a/arch/x86/events/intel/p4.c +++ b/arch/x86/events/intel/p4.c @@ -1006,6 +1006,29 @@ static void p4_pmu_enable_all(int added) } } +static int p4_pmu_set_period(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + s64 left = this_cpu_read(pmc_prev_left[hwc->idx]); + int ret; + + ret = x86_perf_event_set_period(event); + + if (hwc->event_base) { + /* + * This handles erratum N15 in intel doc 249199-029, + * the counter may not be updated correctly on write + * so we need a second write operation to do the trick + * (the official workaround didn't work) + * + * the former idea is taken from OProfile code + */ + wrmsrl(hwc->event_base, (u64)(-left) & x86_pmu.cntval_mask); + } + + return ret; +} + static int p4_pmu_handle_irq(struct pt_regs *regs) { struct perf_sample_data data; @@ -1044,7 +1067,7 @@ static int p4_pmu_handle_irq(struct pt_r /* event overflow for sure */ perf_sample_data_init(&data, 0, hwc->last_period); - if (!x86_perf_event_set_period(event)) + if (!static_call(x86_pmu_set_period)(event)) continue; @@ -1316,6 +1339,9 @@ static __initconst const struct x86_pmu .enable_all = p4_pmu_enable_all, .enable = p4_pmu_enable_event, .disable = p4_pmu_disable_event, + + .set_period = p4_pmu_set_period, + .eventsel = MSR_P4_BPU_CCCR0, .perfctr = MSR_P4_BPU_PERFCTR0, .event_map = p4_pmu_event_map, @@ -1334,15 +1360,6 @@ static __initconst const struct x86_pmu .max_period = (1ULL << (ARCH_P4_CNTRVAL_BITS - 1)) - 1, .hw_config = p4_hw_config, .schedule_events = p4_pmu_schedule_events, - /* - * This handles erratum N15 in intel doc 249199-029, - * the counter may not be updated correctly on write - * so we need a second write operation to do the trick - * (the official workaround didn't work) - * - * the former idea is taken from OProfile code - */ - .perfctr_second_write = 1, .format_attrs = intel_p4_formats_attr, }; --- a/arch/x86/events/perf_event.h +++ b/arch/x86/events/perf_event.h @@ -772,7 +772,6 @@ struct x86_pmu { struct event_constraint *event_constraints; struct x86_pmu_quirk *quirks; - int perfctr_second_write; void (*limit_period)(struct perf_event *event, s64 *l); /* PMI handler bits */ @@ -1049,6 +1048,7 @@ static inline bool x86_pmu_has_lbr_calls } DECLARE_PER_CPU(struct cpu_hw_events, cpu_hw_events); +DECLARE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left); int x86_perf_event_set_period(struct perf_event *event);