From nobody Mon Apr 6 13:01:26 2026 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 1D89DECAAD5 for ; Thu, 8 Sep 2022 05:11:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229788AbiIHFL2 (ORCPT ); Thu, 8 Sep 2022 01:11:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229777AbiIHFLU (ORCPT ); Thu, 8 Sep 2022 01:11:20 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 7B1F6BADA2; Wed, 7 Sep 2022 22:11:17 -0700 (PDT) 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 E8ED7D6E; Wed, 7 Sep 2022 22:11:22 -0700 (PDT) Received: from a077893.blr.arm.com (unknown [10.162.41.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 52EC53F7B4; Wed, 7 Sep 2022 22:11:12 -0700 (PDT) From: Anshuman Khandual To: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-arm-kernel@lists.infradead.org, peterz@infradead.org, acme@kernel.org, mark.rutland@arm.com, will@kernel.org, catalin.marinas@arm.com Cc: Anshuman Khandual , James Clark , Rob Herring , Marc Zyngier , Ingo Molnar Subject: [PATCH V2 4/7] driver/perf/arm_pmu_platform: Add support for BRBE attributes detection Date: Thu, 8 Sep 2022 10:40:43 +0530 Message-Id: <20220908051046.465307-5-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220908051046.465307-1-anshuman.khandual@arm.com> References: <20220908051046.465307-1-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This adds arm pmu infrastrure to probe BRBE implementation's attributes via driver exported callbacks later. The actual BRBE feature detection will be added by the driver itself. CPU specific BRBE entries, cycle count, format support gets detected during PMU init. This information gets saved in per-cpu struct pmu_hw_events which later helps in operating BRBE during a perf event context. Cc: Will Deacon Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual --- drivers/perf/arm_pmu_platform.c | 34 +++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/perf/arm_pmu_platform.c b/drivers/perf/arm_pmu_platfor= m.c index 513de1f54e2d..800e4a6e8bc3 100644 --- a/drivers/perf/arm_pmu_platform.c +++ b/drivers/perf/arm_pmu_platform.c @@ -172,6 +172,36 @@ static int armpmu_request_irqs(struct arm_pmu *armpmu) return err; } =20 +static void arm_brbe_probe_cpu(void *info) +{ + struct pmu_hw_events *hw_events; + struct arm_pmu *armpmu =3D info; + + /* + * Return from here, if BRBE driver has not been + * implemented for this PMU. This helps prevent + * kernel crash later when brbe_probe() will be + * called on the PMU. + */ + if (!armpmu->brbe_probe) + return; + + hw_events =3D per_cpu_ptr(armpmu->hw_events, smp_processor_id()); + armpmu->brbe_probe(hw_events); +} + +static int armpmu_request_brbe(struct arm_pmu *armpmu) +{ + int cpu, err =3D 0; + + for_each_cpu(cpu, &armpmu->supported_cpus) { + err =3D smp_call_function_single(cpu, arm_brbe_probe_cpu, armpmu, 1); + if (err) + return err; + } + return err; +} + static void armpmu_free_irqs(struct arm_pmu *armpmu) { int cpu; @@ -229,6 +259,10 @@ int arm_pmu_device_probe(struct platform_device *pdev, if (ret) goto out_free_irqs; =20 + ret =3D armpmu_request_brbe(pmu); + if (ret) + goto out_free_irqs; + ret =3D armpmu_register(pmu); if (ret) { dev_err(dev, "failed to register PMU devices!\n"); --=20 2.25.1