From nobody Thu Apr 9 15:04:33 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 A0377C433FE for ; Mon, 7 Nov 2022 06:26:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231297AbiKGG0H (ORCPT ); Mon, 7 Nov 2022 01:26:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40716 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231180AbiKGG0B (ORCPT ); Mon, 7 Nov 2022 01:26:01 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id EF32512A93; Sun, 6 Nov 2022 22:25:57 -0800 (PST) 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 DF2191FB; Sun, 6 Nov 2022 22:26:03 -0800 (PST) Received: from a077893.blr.arm.com (unknown [10.162.42.7]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 0DB8B3F534; Sun, 6 Nov 2022 22:25:52 -0800 (PST) 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 , Mark Brown , James Clark , Rob Herring , Marc Zyngier , Suzuki Poulose , Ingo Molnar Subject: [PATCH V5 4/7] driver/perf/arm_pmu_platform: Add support for BRBE attributes detection Date: Mon, 7 Nov 2022 11:55:11 +0530 Message-Id: <20221107062514.2851047-5-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221107062514.2851047-1-anshuman.khandual@arm.com> References: <20221107062514.2851047-1-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 933b96e243b8..acdc445081aa 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