Commit 43fc9a2f authored by Mark Rutland's avatar Mark Rutland Committed by Will Deacon
Browse files

arm_pmu: acpi: check for mismatched PPIs 



The arm_pmu platform code explicitly checks for mismatched PPIs at probe
time, while the ACPI code leaves this to the core code. Future
refactoring will make this difficult for the core code to check, so
let's have the ACPI code check this explicitly.

As before, upon a failure we'll continue on without an interrupt. Ho
hum.

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 0dc1a185

drivers/perf/arm_pmu.c

+4 −13
Original line number Diff line number Diff line
@@ -543,19 +543,7 @@ int armpmu_request_irq(struct arm_pmu *armpmu, int cpu) 
	if (!irq)

		return 0;



	if (irq_is_percpu_devid(irq) && cpumask_empty(&armpmu->active_irqs)) {

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

					 &hw_events->percpu_pmu);

	} else if (irq_is_percpu_devid(irq)) {

		int other_cpu = cpumask_first(&armpmu->active_irqs);

		int other_irq = per_cpu(hw_events->irq, other_cpu);



		if (irq != other_irq) {

			pr_warn("mismatched PPIs detected.\n");

			err = -EINVAL;

			goto err_out;

		}

	} else {

	if (!irq_is_percpu_devid(irq)) {

		unsigned long irq_flags;



		err = irq_force_affinity(irq, cpumask_of(cpu));
@@ -572,6 +560,9 @@ int armpmu_request_irq(struct arm_pmu *armpmu, int cpu) 


		err = request_irq(irq, handler, irq_flags, "arm-pmu",

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

	} else if (cpumask_empty(&armpmu->active_irqs)) {

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

					 &hw_events->percpu_pmu);

	}



	if (err)

drivers/perf/arm_pmu_acpi.c

+38 −4
Original line number Diff line number Diff line
@@ -11,6 +11,8 @@ 
#include <linux/acpi.h>

#include <linux/cpumask.h>

#include <linux/init.h>

#include <linux/irq.h>

#include <linux/irqdesc.h>

#include <linux/percpu.h>

#include <linux/perf/arm_pmu.h>
@@ -139,6 +141,35 @@ static struct arm_pmu *arm_pmu_acpi_find_alloc_pmu(void) 
	return pmu;

}



/*

 * Check whether the new IRQ is compatible with those already associated with

 * the PMU (e.g. we don't have mismatched PPIs).

 */

static bool pmu_irq_matches(struct arm_pmu *pmu, int irq)

{

	struct pmu_hw_events __percpu *hw_events = pmu->hw_events;

	int cpu;



	if (!irq)

		return true;



	for_each_cpu(cpu, &pmu->supported_cpus) {

		int other_irq = per_cpu(hw_events->irq, cpu);

		if (!other_irq)

			continue;



		if (irq == other_irq)

			continue;

		if (!irq_is_percpu_devid(irq) && !irq_is_percpu_devid(other_irq))

			continue;



		pr_warn("mismatched PPIs detected\n");

		return false;

	}



	return true;

}



/*

 * This must run before the common arm_pmu hotplug logic, so that we can

 * associate a CPU and its interrupt before the common code tries to manage the
@@ -164,18 +195,21 @@ static int arm_pmu_acpi_cpu_starting(unsigned int cpu) 
	if (!pmu)

		return -ENOMEM;



	cpumask_set_cpu(cpu, &pmu->supported_cpus);



	per_cpu(probed_pmus, cpu) = pmu;



	if (pmu_irq_matches(pmu, irq)) {

		hw_events = pmu->hw_events;

		per_cpu(hw_events->irq, cpu) = irq;

	}



	cpumask_set_cpu(cpu, &pmu->supported_cpus);



	/*

	 * Log and request the IRQ so the core arm_pmu code can manage it.  In

	 * some situations (e.g. mismatched PPIs), we may fail to request the

	 * IRQ. However, it may be too late for us to do anything about it.

	 * The common ARM PMU code will log a warning in this case.

	 */

	hw_events = pmu->hw_events;

	per_cpu(hw_events->irq, cpu) = irq;

	armpmu_request_irq(pmu, cpu);



	/*

drivers/perf/arm_pmu_platform.c

+0 −7
Original line number Diff line number Diff line
@@ -127,13 +127,6 @@ static int pmu_parse_irqs(struct arm_pmu *pmu) 
			pdev->dev.of_node);

	}



	/*

	 * Some platforms have all PMU IRQs OR'd into a single IRQ, with a

	 * special platdata function that attempts to demux them.

	 */

	if (dev_get_platdata(&pdev->dev))

		cpumask_setall(&pmu->supported_cpus);



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

		int cpu, irq;

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