Commit 92f701e1 authored by Mark Rutland's avatar Mark Rutland Committed by Will Deacon
Browse files

ARM: perf: indirect access to cpu_hw_events 



Currently, cpu_hw_events is a global per-CPU variable. To enable
support for multiple PMUs, there needs to be a mapping from an instance
of arm_pmu to its cpu_hw_events. Additionally, as system PMUs are not
CPU-affine, they should not have this stored per-CPU.

This patch moves access to the hardware events data behind an accessor
function (arm_pmu::get_hw_events). This allows each instance to have
its own hardware event data, which can be stored per-CPU or globally as
required.

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Reviewed-by: default avatarWill Deacon <will.deacon@arm.com>
Reviewed-by: default avatarJamie Iles <jamie@jamieiles.com>
Reviewed-by: default avatarAshwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent a9356a04

arch/arm/kernel/perf_event.c

+15 −3
Original line number Diff line number Diff line
@@ -84,6 +84,7 @@ struct arm_pmu { 
	struct mutex	reserve_mutex;

	u64		max_period;

	struct platform_device	*plat_device;

	struct cpu_hw_events	*(*get_hw_events)(void);

};



/* Set at runtime when we know what CPU type we are. */
@@ -284,7 +285,7 @@ armpmu_start(struct perf_event *event, int flags) 
static void

armpmu_del(struct perf_event *event, int flags)

{

	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);

	struct cpu_hw_events *cpuc = armpmu->get_hw_events();

	struct hw_perf_event *hwc = &event->hw;

	int idx = hwc->idx;
@@ -300,7 +301,7 @@ armpmu_del(struct perf_event *event, int flags) 
static int

armpmu_add(struct perf_event *event, int flags)

{

	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);

	struct cpu_hw_events *cpuc = armpmu->get_hw_events();

	struct hw_perf_event *hwc = &event->hw;

	int idx;

	int err = 0;
@@ -585,7 +586,7 @@ static void armpmu_enable(struct pmu *pmu) 
{

	/* Enable all of the perf events on hardware. */

	int idx, enabled = 0;

	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);

	struct cpu_hw_events *cpuc = armpmu->get_hw_events();



	for (idx = 0; idx < armpmu->num_events; ++idx) {

		struct perf_event *event = cpuc->events[idx];
@@ -678,6 +679,16 @@ static int __init register_pmu_driver(void) 
}

device_initcall(register_pmu_driver);



static struct cpu_hw_events *armpmu_get_cpu_events(void)

{

	return &__get_cpu_var(cpu_hw_events);

}



static void __init cpu_pmu_init(struct arm_pmu *armpmu)

{

	armpmu->get_hw_events = armpmu_get_cpu_events;

}



/*

 * CPU PMU identification and registration.

 */
@@ -728,6 +739,7 @@ init_hw_perf_events(void) 
	if (armpmu) {

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

			armpmu->name, armpmu->num_events);

		cpu_pmu_init(armpmu);

		armpmu_init(armpmu);

		perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);

	} else {

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