From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH v9 07/10] arm: arm64: pmu: Assign platform PMU CPU affinity Date: Fri, 16 Sep 2016 14:29:53 +0100 Message-ID: <20160916132953.GR3380@arm.com> References: <1473892358-22574-1-git-send-email-jeremy.linton@arm.com> <1473892358-22574-8-git-send-email-jeremy.linton@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from foss.arm.com ([217.140.101.70]:56934 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761721AbcIPN3x (ORCPT ); Fri, 16 Sep 2016 09:29:53 -0400 Content-Disposition: inline In-Reply-To: <1473892358-22574-8-git-send-email-jeremy.linton@arm.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Jeremy Linton Cc: linux-arm-kernel@lists.infradead.org, mark.rutland@arm.com, punit.agrawal@arm.com, linux-acpi@vger.kernel.org, mlangsdorf@redhat.com, steve.capper@arm.com On Wed, Sep 14, 2016 at 05:32:35PM -0500, Jeremy Linton wrote: > On systems with multiple PMU types the PMU to CPU affinity > needs to be detected and set. The CPU to interrupt affinity > should also be set. > > Signed-off-by: Jeremy Linton > --- > drivers/perf/arm_pmu.c | 63 ++++++++++++++++++++++++++++++++++++++++++-------- > 1 file changed, 53 insertions(+), 10 deletions(-) > > diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c > index 58117d7..63f16a5 100644 > --- a/drivers/perf/arm_pmu.c > +++ b/drivers/perf/arm_pmu.c > @@ -11,6 +11,7 @@ > */ > #define pr_fmt(fmt) "hw perfevents: " fmt > > +#include > #include > #include > #include > @@ -24,6 +25,7 @@ > #include > #include > > +#include > #include > #include > > @@ -876,25 +878,67 @@ static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu) > } > > /* > - * CPU PMU identification and probing. > + * CPU PMU identification and probing. Its possible to have > + * multiple CPU types in an ARM machine. Assure that we are > + * picking the right PMU types based on the CPU in question > */ > -static int probe_current_pmu(struct arm_pmu *pmu, > - const struct pmu_probe_info *info) > +static int probe_plat_pmu(struct arm_pmu *pmu, > + const struct pmu_probe_info *info, > + unsigned int pmuid) > { > - int cpu = get_cpu(); > - unsigned int cpuid = read_cpuid_id(); > int ret = -ENODEV; > + int cpu; > + int aff_ctr = 0; > + static int duplicate_pmus; > + struct platform_device *pdev = pmu->plat_device; > + int irq = platform_get_irq(pdev, 0); > > - pr_info("probing PMU on CPU %d\n", cpu); > + if (irq >= 0 && !irq_is_percpu(irq)) { > + pmu->irq_affinity = kcalloc(pdev->num_resources, sizeof(int), > + GFP_KERNEL); > + if (!pmu->irq_affinity) > + return -ENOMEM; > + } > > + for_each_possible_cpu(cpu) { > + unsigned int cpuid = read_specific_cpuid(cpu); > + > + if (cpuid == pmuid) { > + cpumask_set_cpu(cpu, &pmu->supported_cpus); > + if (pmu->irq_affinity) { > + pmu->irq_affinity[aff_ctr] = cpu; > + aff_ctr++; > + } > + } > + } > + > + /* find the type of PMU given the CPU */ > for (; info->init != NULL; info++) { > - if ((cpuid & info->mask) != info->cpuid) > + if ((pmuid & info->mask) != info->cpuid) > continue; > ret = info->init(pmu); > + /* > + * if this pmu declaration is unspecified and we have > + * previously found a PMU on this platform then append > + * a PMU number to the pmu name. This avoids changing > + * the names of PMUs that are specific to a class of CPUs. > + * The assumption is that if we match a specific PMU in the > + * provided pmu_probe_info then it's unique, and another PMU > + * in the system will match a different entry rather than > + * needing the _number to assure its unique. > + */ > + if ((!info->cpuid) && (duplicate_pmus)) { Hmm, the duplicate_pmus check looks a little odd here. Doesn't it mean that you'd end up with things like: "arm,armv8-pmuv3" "arm,armv8-pmuv3_1" which looks needlessly fiddly to parse. Is this intentional? Will