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Commit b6c084d7 authored by Will Deacon's avatar Will Deacon
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ARM: perf: extend interrupt-affinity property for PPIs 



On systems containing multiple, heterogeneous clusters we need a way to
associate a PMU "device" with the CPU(s) on which it exists. For PMUs
that signal overflow with SPIs, this relationship is determined via the
"interrupt-affinity" property, which contains a list of phandles to CPU
nodes for the PMU. For PMUs using PPIs, the per-cpu nature of the
interrupt isn't enough to determine the set of CPUs which actually
contain the device.

This patch allows the interrupt-affinity property to be specified on a
PMU node irrespective of the interrupt type. For PPIs, it identifies
the set of CPUs signalling the PPI in question.

Tested-by: Stephen Boyd <sboyd@codeaurora.org> # Krait PMU
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 8ae81c25

Documentation/devicetree/bindings/arm/pmu.txt

+9 −3
Original line number Diff line number Diff line
@@ -26,13 +26,19 @@ Required properties: 


Optional properties:



- interrupt-affinity : Valid only when using SPIs, specifies a list of phandles

                       to CPU nodes corresponding directly to the affinity of

- interrupt-affinity : When using SPIs, specifies a list of phandles to CPU

                       nodes corresponding directly to the affinity of

		       the SPIs listed in the interrupts property.



                       When using a PPI, specifies a list of phandles to CPU

		       nodes corresponding to the set of CPUs which have

		       a PMU of this type signalling the PPI listed in the

		       interrupts property.



                       This property should be present when there is more than

		       a single SPI.





- qcom,no-pc-write : Indicates that this PMU doesn't support the 0xc and 0xd

                     events.

arch/arm/kernel/perf_event.c

+44 −21
Original line number Diff line number Diff line
@@ -790,32 +790,39 @@ static int probe_current_pmu(struct arm_pmu *pmu, 


static int of_pmu_irq_cfg(struct arm_pmu *pmu)

{

	int i, irq, *irqs;

	int *irqs, i = 0;

	bool using_spi = false;

	struct platform_device *pdev = pmu->plat_device;



	/* Don't bother with PPIs; they're already affine */

	irq = platform_get_irq(pdev, 0);

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

		cpumask_setall(&pmu->supported_cpus);

		return 0;

	}



	irqs = kcalloc(pdev->num_resources, sizeof(*irqs), GFP_KERNEL);

	if (!irqs)

		return -ENOMEM;



	for (i = 0; i < pdev->num_resources; ++i) {

	do {

		struct device_node *dn;

		int cpu;

		int cpu, irq;



		dn = of_parse_phandle(pdev->dev.of_node, "interrupt-affinity",

				      i);

		if (!dn) {

			pr_warn("Failed to parse %s/interrupt-affinity[%d]\n",

				of_node_full_name(pdev->dev.of_node), i);

		/* See if we have an affinity entry */

		dn = of_parse_phandle(pdev->dev.of_node, "interrupt-affinity", i);

		if (!dn)

			break;



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

		irq = platform_get_irq(pdev, i);

		if (irq >= 0) {

			bool spi = !irq_is_percpu(irq);



			if (i > 0 && spi != using_spi) {

				pr_err("PPI/SPI IRQ type mismatch for %s!\n",

					dn->name);

				kfree(irqs);

				return -EINVAL;

			}



			using_spi = spi;

		}



		/* Now look up the logical CPU number */

		for_each_possible_cpu(cpu)

			if (arch_find_n_match_cpu_physical_id(dn, cpu, NULL))

				break;
@@ -824,20 +831,36 @@ static int of_pmu_irq_cfg(struct arm_pmu *pmu) 
			pr_warn("Failed to find logical CPU for %s\n",

				dn->name);

			of_node_put(dn);

			cpumask_setall(&pmu->supported_cpus);

			break;

		}

		of_node_put(dn);



		/* For SPIs, we need to track the affinity per IRQ */

		if (using_spi) {

			if (i >= pdev->num_resources) {

				of_node_put(dn);

				break;

			}



			irqs[i] = cpu;

		cpumask_set_cpu(cpu, &pmu->supported_cpus);

		}



	if (i == pdev->num_resources) {

		/* Keep track of the CPUs containing this PMU type */

		cpumask_set_cpu(cpu, &pmu->supported_cpus);

		of_node_put(dn);

		i++;

	} while (1);



	/* If we didn't manage to parse anything, claim to support all CPUs */

	if (cpumask_weight(&pmu->supported_cpus) == 0)

		cpumask_setall(&pmu->supported_cpus);



	/* If we matched up the IRQ affinities, use them to route the SPIs */

	if (using_spi && i == pdev->num_resources)

		pmu->irq_affinity = irqs;

	} else {

	else

		kfree(irqs);

		cpumask_setall(&pmu->supported_cpus);

	}



	return 0;

}