Commit 2681f018 authored by Mark Rutland's avatar Mark Rutland Committed by Will Deacon
Browse files

drivers/perf: arm_pmu: rework per-cpu allocation 



For historical reasons, we allocate per-cpu data associated with a PMU
rather late, in cpu_pmu_init, after we've parsed whatever hardware
information we were provided with.

In order to allow use to store some per-cpu data early in the probe
path, we need to allocate (and initialise) the per-cpu data earlier.
This patch reworks the way we allocate the pmu and associated per-cpu
data in order to make that possible.

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
[will: make armpmu_{alloc,free} static
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 5d3fa803

drivers/perf/arm_pmu.c

+44 −22
Original line number Diff line number Diff line
@@ -828,29 +828,16 @@ static inline void cpu_pm_pmu_unregister(struct arm_pmu *cpu_pmu) { } 
static int cpu_pmu_init(struct arm_pmu *cpu_pmu)

{

	int err;

	int cpu;

	struct pmu_hw_events __percpu *cpu_hw_events;



	cpu_hw_events = alloc_percpu(struct pmu_hw_events);

	if (!cpu_hw_events)

		return -ENOMEM;



	err = cpuhp_state_add_instance_nocalls(CPUHP_AP_PERF_ARM_STARTING,

					       &cpu_pmu->node);

	if (err)

		goto out_free;

		goto out;



	err = cpu_pm_pmu_register(cpu_pmu);

	if (err)

		goto out_unregister;



	for_each_possible_cpu(cpu) {

		struct pmu_hw_events *events = per_cpu_ptr(cpu_hw_events, cpu);

		raw_spin_lock_init(&events->pmu_lock);

		events->percpu_pmu = cpu_pmu;

	}



	cpu_pmu->hw_events	= cpu_hw_events;

	cpu_pmu->request_irq	= cpu_pmu_request_irq;

	cpu_pmu->free_irq	= cpu_pmu_free_irq;
@@ -876,8 +863,7 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu) 
out_unregister:

	cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_STARTING,

					    &cpu_pmu->node);

out_free:

	free_percpu(cpu_hw_events);

out:

	return err;

}
@@ -886,7 +872,6 @@ static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu) 
	cpu_pm_pmu_unregister(cpu_pmu);

	cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_STARTING,

					    &cpu_pmu->node);

	free_percpu(cpu_pmu->hw_events);

}



/*
@@ -1008,6 +993,45 @@ static int of_pmu_irq_cfg(struct arm_pmu *pmu) 
	return 0;

}



static struct arm_pmu *armpmu_alloc(void)

{

	struct arm_pmu *pmu;

	int cpu;



	pmu = kzalloc(sizeof(*pmu), GFP_KERNEL);

	if (!pmu) {

		pr_info("failed to allocate PMU device!\n");

		goto out;

	}



	pmu->hw_events = alloc_percpu(struct pmu_hw_events);

	if (!pmu->hw_events) {

		pr_info("failed to allocate per-cpu PMU data.\n");

		goto out_free_pmu;

	}



	for_each_possible_cpu(cpu) {

		struct pmu_hw_events *events;



		events = per_cpu_ptr(pmu->hw_events, cpu);

		raw_spin_lock_init(&events->pmu_lock);

		events->percpu_pmu = pmu;

	}



	return pmu;



out_free_pmu:

	kfree(pmu);

out:

	return NULL;

}



static void armpmu_free(struct arm_pmu *pmu)

{

	free_percpu(pmu->hw_events);

	kfree(pmu);

}



int arm_pmu_device_probe(struct platform_device *pdev,

			 const struct of_device_id *of_table,

			 const struct pmu_probe_info *probe_table)
@@ -1018,11 +1042,9 @@ int arm_pmu_device_probe(struct platform_device *pdev, 
	struct arm_pmu *pmu;

	int ret = -ENODEV;



	pmu = kzalloc(sizeof(struct arm_pmu), GFP_KERNEL);

	if (!pmu) {

		pr_info("failed to allocate PMU device!\n");

	pmu = armpmu_alloc();

	if (!pmu)

		return -ENOMEM;

	}



	armpmu_init(pmu);
@@ -1076,7 +1098,7 @@ out_free: 
	pr_info("%s: failed to register PMU devices!\n",

		of_node_full_name(node));

	kfree(pmu->irq_affinity);

	kfree(pmu);

	armpmu_free(pmu);

	return ret;

}

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