From patchwork Wed May 31 04:04:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 13261437 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 714A1C77B73 for ; Wed, 31 May 2023 04:05:56 +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=Lp2RBKi0+sssebQEBUO2soVxTYhzmJXegQ7FYts5eFM=; b=xpUfGRjrKNNzam 5fRuEqdaQJoR+GuB1YfdtPXiJ2lLVRrCYhWbmDheLfGrMY7o6qYmHLspU47V8RzZ74h4L7aHCzue2 q7rrM1N/sTeLHGgvp7JXs1Rvhutwg5o9tPDIsfhP3IY//bMRig4zM4SS7lYlOJz4RI1UV920g95BR vxy4yDuL59WYiHbJf9Om1u6pckiWfZLJf02HrGT6mSwcWLe905HHhdzaKvfmLKg/V2jhFEdI3+D8E CQCDiU2eCQRm1zxuUkqP2hOM/4NGEeziq2UOFEYjhmTEHid+PDdfvpvE3o/FZpYd+YPVGiCBpDfoW +b05uZqZSkMmJ89BBXYg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q4D5a-00FzGc-0N; Wed, 31 May 2023 04:05:34 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q4D5I-00Fz9R-1W for linux-arm-kernel@lists.infradead.org; Wed, 31 May 2023 04:05:18 +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 83F4515BF; Tue, 30 May 2023 21:05:59 -0700 (PDT) Received: from a077893.arm.com (unknown [10.163.73.163]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B60A63F6C4; Tue, 30 May 2023 21:05:08 -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 V11 03/10] arm64/perf: Add branch stack support in struct arm_pmu Date: Wed, 31 May 2023 09:34:21 +0530 Message-Id: <20230531040428.501523-4-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230531040428.501523-1-anshuman.khandual@arm.com> References: <20230531040428.501523-1-anshuman.khandual@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230530_210516_625254_AFD34B19 X-CRM114-Status: GOOD ( 16.00 ) 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 updates 'struct arm_pmu' for branch stack sampling support later. This adds a new 'features' element in the structure to track supported features, and another 'private' element to encapsulate implementation attributes on a given 'struct arm_pmu'. These updates here will help in tracking any branch stack sampling support, which is being added later. This also adds a helper arm_pmu_branch_stack_supported(). This also enables perf branch stack sampling event on all 'struct arm pmu', supporting the feature but after removing the current gate that blocks such events unconditionally in armpmu_event_init(). Instead a quick probe can be initiated via arm_pmu_branch_stack_supported() to ascertain the support. 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 --- drivers/perf/arm_pmu.c | 3 +-- include/linux/perf/arm_pmu.h | 12 +++++++++++- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index aada47e3b126..d4a4f2bd89a5 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -510,8 +510,7 @@ static int armpmu_event_init(struct perf_event *event) !cpumask_test_cpu(event->cpu, &armpmu->supported_cpus)) return -ENOENT; - /* does not support taken branch sampling */ - if (has_branch_stack(event)) + if (has_branch_stack(event) && !arm_pmu_branch_stack_supported(armpmu)) return -EOPNOTSUPP; return __hw_perf_event_init(event); diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h index f7fbd162ca4c..0da745eaf426 100644 --- a/include/linux/perf/arm_pmu.h +++ b/include/linux/perf/arm_pmu.h @@ -102,7 +102,9 @@ struct arm_pmu { int (*map_event)(struct perf_event *event); void (*sched_task)(struct perf_event_pmu_context *pmu_ctx, bool sched_in); int num_events; - bool secure_access; /* 32-bit ARM only */ + unsigned int secure_access : 1, /* 32-bit ARM only */ + has_branch_stack: 1, /* 64-bit ARM only */ + reserved : 30; #define ARMV8_PMUV3_MAX_COMMON_EVENTS 0x40 DECLARE_BITMAP(pmceid_bitmap, ARMV8_PMUV3_MAX_COMMON_EVENTS); #define ARMV8_PMUV3_EXT_COMMON_EVENT_BASE 0x4000 @@ -118,8 +120,16 @@ struct arm_pmu { /* Only to be used by ACPI probing code */ unsigned long acpi_cpuid; + + /* Implementation specific attributes */ + void *private; }; +static inline bool arm_pmu_branch_stack_supported(struct arm_pmu *armpmu) +{ + return armpmu->has_branch_stack; +} + #define to_arm_pmu(p) (container_of(p, struct arm_pmu, pmu)) u64 armpmu_event_update(struct perf_event *event);