From patchwork Thu Jun 15 13:32:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 13281282 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AD2C3EB64DB for ; Thu, 15 Jun 2023 13:34:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=3eh0WvqItaK+K08xR/qd8eiZtf6eR3XtVQV23X9a1dc=; b=ARdSpw9rWgUitF ebdGAuo0xpZM68aGtV8L2ySAeL9ZzJiGJV02qcWKPdOluxYMMM8WkDYXKAnK1fZumopsFL1k7V4Yj R3I9/JYkqNGg+KalKMiyyqK1cu4F44vdk2abLmRaNob+lOqCJkZOZ3qqRrTCyQcqGtK+YpUYPMVcQ ume8jjM1oryf8L0Zb7+Z8tYQWygfIOm9qbByw7bSr9A5kThM/l61jw1WiFo+HShdz+7AfE2xK0HUG f03GCgBuEKhBzzMYleAXnHm/11yiQ2uK0+dwlqMicXej1iZvKQXVO9xk+/V+HFdqrmtm3xBgzkT5z BqOM8lOPNc2PQsvyfSjg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q9n6i-00F152-2h; Thu, 15 Jun 2023 13:33:48 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q9n6e-00F12D-1M for linux-arm-kernel@lists.infradead.org; Thu, 15 Jun 2023 13:33:46 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7FDEB1FB; Thu, 15 Jun 2023 06:34:27 -0700 (PDT) Received: from a077893.arm.com (unknown [10.163.46.86]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 852AD3F64C; Thu, 15 Jun 2023 06:33:37 -0700 (PDT) From: Anshuman Khandual To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com Cc: Anshuman Khandual , Mark Brown , James Clark , Rob Herring , Marc Zyngier , Suzuki Poulose , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , linux-perf-users@vger.kernel.org Subject: [PATCH V12 09/10] arm64/perf: Implement branch records save on task sched out Date: Thu, 15 Jun 2023 19:02:38 +0530 Message-Id: <20230615133239.442736-10-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230615133239.442736-1-anshuman.khandual@arm.com> References: <20230615133239.442736-1-anshuman.khandual@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230615_063344_577946_EC391FEE X-CRM114-Status: GOOD ( 17.71 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This modifies current armv8pmu_sched_task(), to implement a branch records save mechanism via armv8pmu_branch_save() when a task scheds out of a cpu. BRBE is paused and disabled for all exception levels before branch records get captured, which then get concatenated with all existing stored records present in the task context maintaining the contiguity. Although the final length of the concatenated buffer does not exceed implemented BRBE length. Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Tested-by: James Clark Signed-off-by: Anshuman Khandual Acked-by: Mark Rutland --- arch/arm64/include/asm/perf_event.h | 2 ++ drivers/perf/arm_brbe.c | 30 +++++++++++++++++++++++++++++ drivers/perf/arm_pmuv3.c | 14 ++++++++++++-- 3 files changed, 44 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/perf_event.h b/arch/arm64/include/asm/perf_event.h index b0c12a5882df..36e7dfb466a6 100644 --- a/arch/arm64/include/asm/perf_event.h +++ b/arch/arm64/include/asm/perf_event.h @@ -40,6 +40,7 @@ void armv8pmu_branch_probe(struct arm_pmu *arm_pmu); void armv8pmu_branch_reset(void); int armv8pmu_task_ctx_cache_alloc(struct arm_pmu *arm_pmu); void armv8pmu_task_ctx_cache_free(struct arm_pmu *arm_pmu); +void armv8pmu_branch_save(struct arm_pmu *arm_pmu, void *ctx); #else static inline void armv8pmu_branch_read(struct pmu_hw_events *cpuc, struct perf_event *event) { @@ -66,6 +67,7 @@ static inline void armv8pmu_branch_probe(struct arm_pmu *arm_pmu) { } static inline void armv8pmu_branch_reset(void) { } static inline int armv8pmu_task_ctx_cache_alloc(struct arm_pmu *arm_pmu) { return 0; } static inline void armv8pmu_task_ctx_cache_free(struct arm_pmu *arm_pmu) { } +static inline void armv8pmu_branch_save(struct arm_pmu *arm_pmu, void *ctx) { } #endif #endif #endif diff --git a/drivers/perf/arm_brbe.c b/drivers/perf/arm_brbe.c index f6693699fade..3bb17ced2b1d 100644 --- a/drivers/perf/arm_brbe.c +++ b/drivers/perf/arm_brbe.c @@ -171,6 +171,36 @@ static int stitch_stored_live_entries(struct brbe_regset *stored, return min(nr_live + nr_stored, nr_max); } +static int brbe_branch_save(int nr_hw_entries, struct brbe_regset *live) +{ + u64 brbfcr = read_sysreg_s(SYS_BRBFCR_EL1); + int nr_live; + + write_sysreg_s(brbfcr | BRBFCR_EL1_PAUSED, SYS_BRBFCR_EL1); + isb(); + + nr_live = capture_brbe_regset(nr_hw_entries, live); + + write_sysreg_s(brbfcr & ~BRBFCR_EL1_PAUSED, SYS_BRBFCR_EL1); + isb(); + + return nr_live; +} + +void armv8pmu_branch_save(struct arm_pmu *arm_pmu, void *ctx) +{ + struct arm64_perf_task_context *task_ctx = ctx; + struct brbe_regset live[BRBE_MAX_ENTRIES]; + int nr_live, nr_store, nr_hw_entries; + + nr_hw_entries = brbe_get_numrec(arm_pmu->reg_brbidr); + nr_live = brbe_branch_save(nr_hw_entries, live); + nr_store = task_ctx->nr_brbe_records; + nr_store = stitch_stored_live_entries(task_ctx->store, live, nr_store, + nr_live, nr_hw_entries); + task_ctx->nr_brbe_records = nr_store; +} + /* * Generic perf branch filters supported on BRBE * diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c index 3c079051a63a..53f404618891 100644 --- a/drivers/perf/arm_pmuv3.c +++ b/drivers/perf/arm_pmuv3.c @@ -907,9 +907,19 @@ static int armv8pmu_user_event_idx(struct perf_event *event) static void armv8pmu_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in) { struct arm_pmu *armpmu = to_arm_pmu(pmu_ctx->pmu); + void *task_ctx = pmu_ctx ? pmu_ctx->task_ctx_data : NULL; - if (sched_in && armpmu->has_branch_stack) - armv8pmu_branch_reset(); + if (armpmu->has_branch_stack) { + /* Save branch records in task_ctx on sched out */ + if (task_ctx && !sched_in) { + armv8pmu_branch_save(armpmu, task_ctx); + return; + } + + /* Reset branch records on sched in */ + if (sched_in) + armv8pmu_branch_reset(); + } } /*