Commit 03b7898d authored by Mark Rutland's avatar Mark Rutland Committed by Will Deacon
Browse files

ARM: perf: move active_events into struct arm_pmu 



This patch moves the active_events counter into struct arm_pmu, in
preparation for supporting multiple PMUs. This also moves
pmu_reserve_mutex, as it is used to guard accesses to active_events.

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>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent c47f8684

arch/arm/kernel/perf_event.c

+20 −11
Original line number Diff line number Diff line
@@ -82,6 +82,8 @@ struct arm_pmu { 
	const unsigned	(*event_map)[PERF_COUNT_HW_MAX];

	u32		raw_event_mask;

	int		num_events;

	atomic_t	active_events;

	struct mutex	reserve_mutex;

	u64		max_period;

};
@@ -454,15 +456,15 @@ armpmu_reserve_hardware(void) 
	return 0;

}



static atomic_t active_events = ATOMIC_INIT(0);

static DEFINE_MUTEX(pmu_reserve_mutex);



static void

hw_perf_event_destroy(struct perf_event *event)

{

	if (atomic_dec_and_mutex_lock(&active_events, &pmu_reserve_mutex)) {

	atomic_t *active_events	 = &armpmu->active_events;

	struct mutex *pmu_reserve_mutex = &armpmu->reserve_mutex;



	if (atomic_dec_and_mutex_lock(active_events, pmu_reserve_mutex)) {

		armpmu_release_hardware();

		mutex_unlock(&pmu_reserve_mutex);

		mutex_unlock(pmu_reserve_mutex);

	}

}
@@ -543,6 +545,7 @@ __hw_perf_event_init(struct perf_event *event) 
static int armpmu_event_init(struct perf_event *event)

{

	int err = 0;

	atomic_t *active_events = &armpmu->active_events;



	switch (event->attr.type) {

	case PERF_TYPE_RAW:
@@ -556,15 +559,14 @@ static int armpmu_event_init(struct perf_event *event) 


	event->destroy = hw_perf_event_destroy;



	if (!atomic_inc_not_zero(&active_events)) {

		mutex_lock(&pmu_reserve_mutex);

		if (atomic_read(&active_events) == 0) {

	if (!atomic_inc_not_zero(active_events)) {

		mutex_lock(&armpmu->reserve_mutex);

		if (atomic_read(active_events) == 0)

			err = armpmu_reserve_hardware();

		}



		if (!err)

			atomic_inc(&active_events);

		mutex_unlock(&pmu_reserve_mutex);

			atomic_inc(active_events);

		mutex_unlock(&armpmu->reserve_mutex);

	}



	if (err)
@@ -613,6 +615,12 @@ static struct pmu pmu = { 
	.read		= armpmu_read,

};



static void __init armpmu_init(struct arm_pmu *armpmu)

{

	atomic_set(&armpmu->active_events, 0);

	mutex_init(&armpmu->reserve_mutex);

}



/* Include the PMU-specific implementations. */

#include "perf_event_xscale.c"

#include "perf_event_v6.c"
@@ -718,6 +726,7 @@ init_hw_perf_events(void) 
	if (armpmu) {

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

			armpmu->name, armpmu->num_events);

		armpmu_init(armpmu);

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

	} else {

		pr_info("no hardware support available\n");

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