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Date: Mon, 17 Nov 2014 11:20:35 +0000 From: Will Deacon <will.deacon@....com> To: Mark Rutland <mark.rutland@....com> Cc: "linux-arm-kernel@...ts.infradead.org" <linux-arm-kernel@...ts.infradead.org>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org> Subject: Re: [PATCH 09/11] arm: perf: parse cpu affinity from dt On Fri, Nov 07, 2014 at 04:25:34PM +0000, Mark Rutland wrote: > The current way we read interrupts form devicetree assumes that > interrupts are in increasing order of logical cpu id (MPIDR.Aff{2,1,0}), > and that these logical ids are in a contiguous block. This may not be > the case in general - after a kexec cpu ids may be arbitrarily assigned, > and multi-cluster systems do not have a contiguous range of cpu ids. > > This patch parses cpu affinity information for interrupts from an > optional "interrupts-affinity" devicetree property described in the > devicetree binding document. Support for existing dts and board files > remains. > > Signed-off-by: Mark Rutland <mark.rutland@....com> > --- > arch/arm/include/asm/pmu.h | 12 +++ > arch/arm/kernel/perf_event_cpu.c | 196 +++++++++++++++++++++++++++++---------- > 2 files changed, 161 insertions(+), 47 deletions(-) > > diff --git a/arch/arm/include/asm/pmu.h b/arch/arm/include/asm/pmu.h > index b630a44..92fc1da 100644 > --- a/arch/arm/include/asm/pmu.h > +++ b/arch/arm/include/asm/pmu.h > @@ -12,6 +12,7 @@ > #ifndef __ARM_PMU_H__ > #define __ARM_PMU_H__ > > +#include <linux/cpumask.h> > #include <linux/interrupt.h> > #include <linux/perf_event.h> > > @@ -89,6 +90,15 @@ struct pmu_hw_events { > struct arm_pmu *percpu_pmu; > }; > > +/* > + * For systems with heterogeneous PMUs, we need to know which CPUs each > + * (possibly percpu) IRQ targets. Map between them with an array of these. > + */ > +struct cpu_irq { > + cpumask_t cpus; > + int irq; > +}; > + > struct arm_pmu { > struct pmu pmu; > cpumask_t active_irqs; > @@ -118,6 +128,8 @@ struct arm_pmu { > struct platform_device *plat_device; > struct pmu_hw_events __percpu *hw_events; > struct notifier_block hotplug_nb; > + int nr_irqs; > + struct cpu_irq *irq_map; > }; > > #define to_arm_pmu(p) (container_of(p, struct arm_pmu, pmu)) > diff --git a/arch/arm/kernel/perf_event_cpu.c b/arch/arm/kernel/perf_event_cpu.c > index dfcaba5..f09c8a0 100644 > --- a/arch/arm/kernel/perf_event_cpu.c > +++ b/arch/arm/kernel/perf_event_cpu.c > @@ -85,20 +85,27 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu) > struct platform_device *pmu_device = cpu_pmu->plat_device; > struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events; > > - irqs = min(pmu_device->num_resources, num_possible_cpus()); > + irqs = cpu_pmu->nr_irqs; > > - irq = platform_get_irq(pmu_device, 0); > - if (irq >= 0 && irq_is_percpu(irq)) { > - on_each_cpu(cpu_pmu_disable_percpu_irq, &irq, 1); > - free_percpu_irq(irq, &hw_events->percpu_pmu); > - } else { > - for (i = 0; i < irqs; ++i) { > - if (!cpumask_test_and_clear_cpu(i, &cpu_pmu->active_irqs)) > - continue; > - irq = platform_get_irq(pmu_device, i); > - if (irq >= 0) > - free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, i)); > + for (i = 0; i < irqs; i++) { > + struct cpu_irq *map = &cpu_pmu->irq_map[i]; > + irq = map->irq; > + > + if (irq <= 0) > + continue; > + > + if (irq_is_percpu(irq)) { > + on_each_cpu(cpu_pmu_disable_percpu_irq, &irq, 1); Hmm, ok, so we're assuming that all the PMUs will be wired with PPIs in this case. I have a patch allowing per-cpu interrupts to be requested for a cpumask, but I suppose that can wait until it's actually needed. Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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