From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751760Ab3KRNqT (ORCPT ); Mon, 18 Nov 2013 08:46:19 -0500 Received: from inca-roads.misterjones.org ([213.251.177.50]:58530 "EHLO inca-roads.misterjones.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750880Ab3KRNqM (ORCPT ); Mon, 18 Nov 2013 08:46:12 -0500 To: Vinayak Kale Subject: Re: [PATCH V3 2/2] arm64: perf: add support for percpu pmu interrupt X-PHP-Originating-Script: 0:main.inc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 18 Nov 2013 13:46:09 +0000 From: Marc Zyngier Cc: , , , , , , Tuan Phan Organization: ARM Ltd In-Reply-To: <1384780949-10922-3-git-send-email-vkale@apm.com> References: <1384780949-10922-1-git-send-email-vkale@apm.com> <1384780949-10922-3-git-send-email-vkale@apm.com> Message-ID: <3545e6650079200b6b364df14ef14a4f@www.loen.fr> User-Agent: Roundcube Webmail/0.7.2 X-SA-Exim-Connect-IP: X-SA-Exim-Rcpt-To: vkale@apm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, will.deacon@arm.com, patches@apm.com, jcm@redhat.com, tglx@linutronix.de, tphan@apm.com X-SA-Exim-Mail-From: marc.zyngier@arm.com X-SA-Exim-Scanned: No (on cheepnis.misterjones.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Vinayak, On 2013-11-18 13:22, Vinayak Kale wrote: > Add support for irq registration when pmu interrupt is percpu. > > Signed-off-by: Vinayak Kale > Signed-off-by: Tuan Phan > --- > arch/arm64/kernel/perf_event.c | 102 > +++++++++++++++++++++++++++++----------- > 1 file changed, 74 insertions(+), 28 deletions(-) > > diff --git a/arch/arm64/kernel/perf_event.c > b/arch/arm64/kernel/perf_event.c > index cea1594..23475f6 100644 > --- a/arch/arm64/kernel/perf_event.c > +++ b/arch/arm64/kernel/perf_event.c > @@ -22,6 +22,7 @@ > > #include > #include > +#include > #include > #include > #include > @@ -363,22 +364,51 @@ validate_group(struct perf_event *event) > } > > static void > +armpmu_disable_percpu_irq(void *data) > +{ > + struct arm_pmu *armpmu = data; > + struct platform_device *pmu_device = armpmu->plat_device; > + int irq = platform_get_irq(pmu_device, 0); > + > + cpumask_test_and_clear_cpu(smp_processor_id(), > &armpmu->active_irqs); > + disable_percpu_irq(irq); > +} > + > +static void > armpmu_release_hardware(struct arm_pmu *armpmu) > { > int i, irq, irqs; > struct platform_device *pmu_device = armpmu->plat_device; > > - irqs = min(pmu_device->num_resources, num_possible_cpus()); > + irq = platform_get_irq(pmu_device, 0); > > - for (i = 0; i < irqs; ++i) { > - if (!cpumask_test_and_clear_cpu(i, &armpmu->active_irqs)) > - continue; > - irq = platform_get_irq(pmu_device, i); > - if (irq >= 0) > - free_irq(irq, armpmu); > + if (irq_to_desc(irq) && irq_is_percpu(irq)) { Why do you need to check the irq_desc here? It really looks like a misuse of the API. Instead, you should check the value of irq itself (it should be strictly positive). > + on_each_cpu(armpmu_disable_percpu_irq, armpmu, 1); > + free_percpu_irq(irq, &cpu_hw_events); > + } else { > + irqs = min(pmu_device->num_resources, num_possible_cpus()); > + > + for (i = 0; i < irqs; ++i) { > + if (!cpumask_test_and_clear_cpu(i, &armpmu->active_irqs)) > + continue; > + irq = platform_get_irq(pmu_device, i); > + if (irq >= 0) irq == 0 means "no-irq". You should handle it as an error case. > + free_irq(irq, armpmu); > + } > } > } > > +static void > +armpmu_enable_percpu_irq(void *data) > +{ > + struct arm_pmu *armpmu = data; > + struct platform_device *pmu_device = armpmu->plat_device; > + int irq = platform_get_irq(pmu_device, 0); > + > + enable_percpu_irq(irq, 0); > + cpumask_set_cpu(smp_processor_id(), &armpmu->active_irqs); > +} > + > static int > armpmu_reserve_hardware(struct arm_pmu *armpmu) > { > @@ -396,34 +426,50 @@ armpmu_reserve_hardware(struct arm_pmu *armpmu) > return -ENODEV; > } > > - for (i = 0; i < irqs; ++i) { > - err = 0; > - irq = platform_get_irq(pmu_device, i); > - if (irq < 0) > - continue; > + irq = platform_get_irq(pmu_device, 0); > > - /* > - * If we have a single PMU interrupt that we can't shift, > - * assume that we're running on a uniprocessor machine and > - * continue. Otherwise, continue without this interrupt. > - */ > - if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) { > - pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n", > - irq, i); > - continue; > - } > + if (irq_to_desc(irq) && irq_is_percpu(irq)) { Same comment about irq_to_desc. > + err = request_percpu_irq(irq, armpmu->handle_irq, > + "arm-pmu", &cpu_hw_events); > > - err = request_irq(irq, armpmu->handle_irq, > - IRQF_NOBALANCING, > - "arm-pmu", armpmu); > if (err) { > - pr_err("unable to request IRQ%d for ARM PMU counters\n", > - irq); > + pr_err("unable to request percpu IRQ%d for ARM PMU counters\n", > + irq); > armpmu_release_hardware(armpmu); > return err; > } > > - cpumask_set_cpu(i, &armpmu->active_irqs); > + on_each_cpu(armpmu_enable_percpu_irq, armpmu, 1); > + } else { > + for (i = 0; i < irqs; ++i) { > + err = 0; > + irq = platform_get_irq(pmu_device, i); > + if (irq < 0) Same comment about irq == 0. > + continue; > + > + /* > + * If we have a single PMU interrupt that we can't shift, > + * assume that we're running on a uniprocessor machine and > + * continue. Otherwise, continue without this interrupt. > + */ > + if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) { > + pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n", > + irq, i); > + continue; > + } > + > + err = request_irq(irq, armpmu->handle_irq, > + IRQF_NOBALANCING, > + "arm-pmu", armpmu); > + if (err) { > + pr_err("unable to request IRQ%d for ARM PMU counters\n", > + irq); > + armpmu_release_hardware(armpmu); > + return err; > + } > + > + cpumask_set_cpu(i, &armpmu->active_irqs); > + } > } > > return 0; -- Fast, cheap, reliable. Pick two.