arm_pmu: explicitly enable/disable SPIs at hotplug (6de3f791) · Commits · 戴 / test

To support ACPI systems, we need to request IRQs before CPUs are hotplugged, and thus we need to request IRQs before we know their associated PMU. This is problematic if a PMU IRQ is pending out of reset, as it may be taken before we know the PMU, and thus the IRQ handler won't be able to handle it, leaving it screaming. To avoid such problems, lets request all IRQs in a disabled state, and explicitly enable/disable them at hotplug time, when we're sure the PMU has been probed. Signed-off-by:

Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by:

Will Deacon <will.deacon@arm.com>

drivers/perf/arm_pmu.c

+10 −5

Original line number	Diff line number	Diff line
		@@ -558,6 +558,7 @@ int armpmu_request_irq(struct arm_pmu *armpmu, int cpu)
		IRQF_NOBALANCING \|
		IRQF_NO_THREAD;

		irq_set_status_flags(irq, IRQ_NOAUTOEN);
		err = request_irq(irq, handler, irq_flags, "arm-pmu",
		per_cpu_ptr(&hw_events->percpu_pmu, cpu));
		} else if (cpumask_empty(&armpmu->active_irqs)) {
		@@ -600,10 +601,10 @@ static int arm_perf_starting_cpu(unsigned int cpu, struct hlist_node *node)

		irq = armpmu_get_cpu_irq(pmu, cpu);
		if (irq) {
		if (irq_is_percpu_devid(irq)) {
		if (irq_is_percpu_devid(irq))
		enable_percpu_irq(irq, IRQ_TYPE_NONE);
		return 0;
		}
		else
		enable_irq(irq);
		}

		return 0;
		@@ -618,8 +619,12 @@ static int arm_perf_teardown_cpu(unsigned int cpu, struct hlist_node *node)
		return 0;

		irq = armpmu_get_cpu_irq(pmu, cpu);
		if (irq && irq_is_percpu_devid(irq))
		if (irq) {
		if (irq_is_percpu_devid(irq))
		disable_percpu_irq(irq);
		else
		disable_irq(irq);
		}

		return 0;
		}

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