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Commit c079e157 authored by Patrick Fay's avatar Patrick Fay
Browse files

Perf: arm64: disable irq for hotplug offline 



Currently the hotplug notifier calls cpu_pmu_enable_percpu_irq
when a CPU comes online. The notifier doesn't have a corresponding
call to cpu_pmu_disable_percpu_irq when the CPU goes offline.
Change the code to follow what was done in 3.18 including
tracking whether the PMU is active and the IRQ number in use.

Change-Id: I1835fb543eb483713a30eb6c0ccd4e4a4b9908be
Signed-off-by: default avatarPatrick Fay <pfay@codeaurora.org>
parent 406ab7d2

drivers/perf/arm_pmu.c

+47 −37
Original line number Diff line number Diff line
@@ -367,6 +367,8 @@ armpmu_reserve_hardware(struct arm_pmu *armpmu) 
		return err;

	}



	armpmu->pmu_state = ARM_PMU_STATE_RUNNING;



	return 0;

}
@@ -601,10 +603,12 @@ 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;



	cpu_pmu->pmu_state = ARM_PMU_STATE_GOING_DOWN;



	irqs = min(pmu_device->num_resources, num_possible_cpus());



	irq = platform_get_irq(pmu_device, 0);

	if (irq >= 0 && irq_is_percpu(irq)) {

	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 {
@@ -617,10 +621,11 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu) 
			if (!cpumask_test_and_clear_cpu(cpu, &cpu_pmu->active_irqs))

				continue;

			irq = platform_get_irq(pmu_device, i);

			if (irq >= 0)

			if (irq > 0)

				free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, cpu));

		}

	}

	cpu_pmu->pmu_state = ARM_PMU_STATE_OFF;

}



static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
@@ -639,7 +644,7 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler) 
	}



	irq = platform_get_irq(pmu_device, 0);

	if (irq >= 0 && irq_is_percpu(irq)) {

	if (irq > 0 && irq_is_percpu(irq)) {

		err = request_percpu_irq(irq, handler, "arm-pmu",

					 &hw_events->percpu_pmu);

		if (err) {
@@ -648,6 +653,7 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler) 
			return err;

		}

		on_each_cpu(cpu_pmu_enable_percpu_irq, &irq, 1);

		cpu_pmu->percpu_irq = irq;

	} else {

		for (i = 0; i < irqs; ++i) {

			int cpu = i;
@@ -754,13 +760,6 @@ static void cpu_pm_pmu_common(void *info) 
		return;

	}



	/*

	 * Always reset the PMU registers on power-up even if

	 * there are no events running.

	 */

	if (cmd == CPU_PM_EXIT && armpmu->reset)

		armpmu->reset(armpmu);



	if (!enabled) {

		data->ret = NOTIFY_OK;

		return;
@@ -795,6 +794,13 @@ static int cpu_pm_pmu_notify(struct notifier_block *b, unsigned long cmd, 
		.cpu	= smp_processor_id(),

	};



	/*

	 * Always reset the PMU registers on power-up even if

	 * there are no events running.

	 */

	if (cmd == CPU_PM_EXIT && data.armpmu->reset)

		data.armpmu->reset(data.armpmu);



	cpu_pm_pmu_common(&data);

	return data.ret;

}
@@ -824,6 +830,7 @@ static inline void cpu_pm_pmu_common(void *info) { } 
static int cpu_pmu_notify(struct notifier_block *b, unsigned long action,

			  void *hcpu)

{

	int irq = -1;

	unsigned long masked_action = (action & ~CPU_TASKS_FROZEN);

	struct cpu_pm_pmu_args data = {

		.armpmu	= container_of(b, struct arm_pmu, hotplug_nb),
@@ -835,37 +842,37 @@ static int cpu_pmu_notify(struct notifier_block *b, unsigned long action, 


	switch (masked_action) {

	case CPU_STARTING:

	case CPU_DOWN_FAILED:

		/*

		 * Always reset the PMU registers on power-up even if

		 * there are no events running.

		 */

		if (data.armpmu->reset)

			data.armpmu->reset(data.armpmu);

		if (data.armpmu->pmu_state == ARM_PMU_STATE_RUNNING) {

			if (data.armpmu->plat_device)

				irq = data.armpmu->percpu_irq;

			/* Arm the PMU IRQ before appearing. */

			if (irq > 0 && irq_is_percpu(irq))

				cpu_pmu_enable_percpu_irq(&irq);

			data.cmd = CPU_PM_EXIT;

		break;

			cpu_pm_pmu_common(&data);

		}

		return NOTIFY_OK;

	case CPU_DYING:

		if (data.armpmu->pmu_state != ARM_PMU_STATE_OFF) {

			data.cmd = CPU_PM_ENTER;

		break;

	case CPU_DOWN_FAILED:

		data.cmd = CPU_PM_ENTER_FAILED;

		break;

	case CPU_ONLINE:

		if (data.armpmu->plat_device) {

			struct platform_device *pmu_device =

				data.armpmu->plat_device;

			int irq = platform_get_irq(pmu_device, 0);



			if (irq >= 0 && irq_is_percpu(irq)) {

				smp_call_function_single(data.cpu,

					cpu_pmu_enable_percpu_irq, &irq, 1);

			}

			cpu_pm_pmu_common(&data);

			/* Disarm the PMU IRQ before disappearing. */

			if (data.armpmu->plat_device)

				irq = data.armpmu->percpu_irq;

			if (irq > 0 && irq_is_percpu(irq))

				cpu_pmu_disable_percpu_irq(&irq);

		}

		return NOTIFY_DONE;

		return NOTIFY_OK;

	default:

		return NOTIFY_DONE;

	}



	if (smp_processor_id() == data.cpu)

		cpu_pm_pmu_common(&data);

	else

		smp_call_function_single(data.cpu,

			cpu_pm_pmu_common, &data, 1);



	return data.ret;

}



static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
@@ -966,7 +973,7 @@ static int of_pmu_irq_cfg(struct arm_pmu *pmu) 


		/* Check the IRQ type and prohibit a mix of PPIs and SPIs */

		irq = platform_get_irq(pdev, i);

		if (irq >= 0) {

		if (irq > 0) {

			bool spi = !irq_is_percpu(irq);



			if (i > 0 && spi != using_spi) {
@@ -1085,6 +1092,9 @@ int arm_pmu_device_probe(struct platform_device *pdev, 
	if (ret)

		goto out_destroy;



	pmu->pmu_state  = ARM_PMU_STATE_OFF;

	pmu->percpu_irq = -1;



	pr_info("enabled with %s PMU driver, %d counters available\n",

			pmu->name, pmu->num_events);

include/linux/perf/arm_pmu.h

+8 −0
Original line number Diff line number Diff line
@@ -77,6 +77,12 @@ struct pmu_hw_events { 
	struct arm_pmu		*percpu_pmu;

};



enum armpmu_pmu_states {

	ARM_PMU_STATE_OFF,

	ARM_PMU_STATE_RUNNING,

	ARM_PMU_STATE_GOING_DOWN,

};



struct arm_pmu {

	struct pmu	pmu;

	cpumask_t	active_irqs;
@@ -101,6 +107,8 @@ struct arm_pmu { 
	void		(*free_irq)(struct arm_pmu *);

	int		(*map_event)(struct perf_event *event);

	int		num_events;

	int		pmu_state;

	int		percpu_irq;

	atomic_t	active_events;

	struct mutex	reserve_mutex;

	u64		max_period;