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-rw-r--r--drivers/perf/arm_pmu.c153
-rw-r--r--include/linux/perf/arm_pmu.h4
2 files changed, 50 insertions, 107 deletions
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index e984653b93aa..a1dfe895cb1d 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -352,37 +352,6 @@ static irqreturn_t armpmu_dispatch_irq(int irq, void *dev)
return ret;
}
-static void
-armpmu_release_hardware(struct arm_pmu *armpmu)
-{
- armpmu->free_irq(armpmu);
-}
-
-static int
-armpmu_reserve_hardware(struct arm_pmu *armpmu)
-{
- int err = armpmu->request_irq(armpmu, armpmu_dispatch_irq);
- if (err) {
- armpmu_release_hardware(armpmu);
- return err;
- }
-
- return 0;
-}
-
-static void
-hw_perf_event_destroy(struct perf_event *event)
-{
- struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
- 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(armpmu);
- mutex_unlock(pmu_reserve_mutex);
- }
-}
-
static int
event_requires_mode_exclusion(struct perf_event_attr *attr)
{
@@ -455,8 +424,6 @@ __hw_perf_event_init(struct perf_event *event)
static int armpmu_event_init(struct perf_event *event)
{
struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
- int err = 0;
- atomic_t *active_events = &armpmu->active_events;
/*
* Reject CPU-affine events for CPUs that are of a different class to
@@ -476,26 +443,7 @@ static int armpmu_event_init(struct perf_event *event)
if (armpmu->map_event(event) == -ENOENT)
return -ENOENT;
- event->destroy = hw_perf_event_destroy;
-
- if (!atomic_inc_not_zero(active_events)) {
- mutex_lock(&armpmu->reserve_mutex);
- if (atomic_read(active_events) == 0)
- err = armpmu_reserve_hardware(armpmu);
-
- if (!err)
- atomic_inc(active_events);
- mutex_unlock(&armpmu->reserve_mutex);
- }
-
- if (err)
- return err;
-
- err = __hw_perf_event_init(event);
- if (err)
- hw_perf_event_destroy(event);
-
- return err;
+ return __hw_perf_event_init(event);
}
static void armpmu_enable(struct pmu *pmu)
@@ -555,9 +503,6 @@ static struct attribute_group armpmu_common_attr_group = {
static void armpmu_init(struct arm_pmu *armpmu)
{
- atomic_set(&armpmu->active_events, 0);
- mutex_init(&armpmu->reserve_mutex);
-
armpmu->pmu = (struct pmu) {
.pmu_enable = armpmu_enable,
.pmu_disable = armpmu_disable,
@@ -601,21 +546,7 @@ int perf_num_counters(void)
}
EXPORT_SYMBOL_GPL(perf_num_counters);
-static void cpu_pmu_enable_percpu_irq(void *data)
-{
- int irq = *(int *)data;
-
- enable_percpu_irq(irq, IRQ_TYPE_NONE);
-}
-
-static void cpu_pmu_disable_percpu_irq(void *data)
-{
- int irq = *(int *)data;
-
- disable_percpu_irq(irq);
-}
-
-static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
+static void cpu_pmu_free_irqs(struct arm_pmu *cpu_pmu)
{
int cpu;
struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events;
@@ -626,10 +557,7 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
continue;
if (irq_is_percpu(irq)) {
- on_each_cpu_mask(&cpu_pmu->supported_cpus,
- cpu_pmu_disable_percpu_irq, &irq, 1);
free_percpu_irq(irq, &hw_events->percpu_pmu);
-
break;
}
@@ -640,7 +568,7 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
}
}
-static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
+static int cpu_pmu_request_irqs(struct arm_pmu *cpu_pmu, irq_handler_t handler)
{
int cpu, err;
struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events;
@@ -656,25 +584,9 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
if (err) {
pr_err("unable to request IRQ%d for ARM PMU counters\n",
irq);
- return err;
}
- on_each_cpu_mask(&cpu_pmu->supported_cpus,
- cpu_pmu_enable_percpu_irq, &irq, 1);
-
- break;
- }
-
- /*
- * If we have a single PMU interrupt that we can't shift,
- * assume that we're running on a uniprocessor machine and
- * continue. Otherwise, continue without this interrupt.
- */
- if (irq_set_affinity(irq, cpumask_of(cpu)) &&
- num_possible_cpus() > 1) {
- pr_warn("unable to set irq affinity (irq=%d, cpu=%u)\n",
- irq, cpu);
- continue;
+ return err;
}
err = request_irq(irq, handler,
@@ -692,6 +604,12 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
return 0;
}
+static int armpmu_get_cpu_irq(struct arm_pmu *pmu, int cpu)
+{
+ struct pmu_hw_events __percpu *hw_events = pmu->hw_events;
+ return per_cpu(hw_events->irq, cpu);
+}
+
/*
* PMU hardware loses all context when a CPU goes offline.
* When a CPU is hotplugged back in, since some hardware registers are
@@ -701,11 +619,42 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
static int arm_perf_starting_cpu(unsigned int cpu, struct hlist_node *node)
{
struct arm_pmu *pmu = hlist_entry_safe(node, struct arm_pmu, node);
+ int irq;
if (!cpumask_test_cpu(cpu, &pmu->supported_cpus))
return 0;
if (pmu->reset)
pmu->reset(pmu);
+
+ irq = armpmu_get_cpu_irq(pmu, cpu);
+ if (irq) {
+ if (irq_is_percpu(irq)) {
+ enable_percpu_irq(irq, IRQ_TYPE_NONE);
+ return 0;
+ }
+
+ if (irq_force_affinity(irq, cpumask_of(cpu)) &&
+ num_possible_cpus() > 1) {
+ pr_warn("unable to set irq affinity (irq=%d, cpu=%u)\n",
+ irq, cpu);
+ }
+ }
+
+ return 0;
+}
+
+static int arm_perf_teardown_cpu(unsigned int cpu, struct hlist_node *node)
+{
+ struct arm_pmu *pmu = hlist_entry_safe(node, struct arm_pmu, node);
+ int irq;
+
+ if (!cpumask_test_cpu(cpu, &pmu->supported_cpus))
+ return 0;
+
+ irq = armpmu_get_cpu_irq(pmu, cpu);
+ if (irq && irq_is_percpu(irq))
+ disable_percpu_irq(irq);
+
return 0;
}
@@ -811,8 +760,12 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
{
int err;
- err = cpuhp_state_add_instance_nocalls(CPUHP_AP_PERF_ARM_STARTING,
- &cpu_pmu->node);
+ err = cpu_pmu_request_irqs(cpu_pmu, armpmu_dispatch_irq);
+ if (err)
+ goto out;
+
+ err = cpuhp_state_add_instance(CPUHP_AP_PERF_ARM_STARTING,
+ &cpu_pmu->node);
if (err)
goto out;
@@ -820,14 +773,6 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
if (err)
goto out_unregister;
- cpu_pmu->request_irq = cpu_pmu_request_irq;
- cpu_pmu->free_irq = cpu_pmu_free_irq;
-
- /* Ensure the PMU has sane values out of reset. */
- if (cpu_pmu->reset)
- on_each_cpu_mask(&cpu_pmu->supported_cpus, cpu_pmu->reset,
- cpu_pmu, 1);
-
/*
* This is a CPU PMU potentially in a heterogeneous configuration (e.g.
* big.LITTLE). This is not an uncore PMU, and we have taken ctx
@@ -842,6 +787,7 @@ out_unregister:
cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_STARTING,
&cpu_pmu->node);
out:
+ cpu_pmu_free_irqs(cpu_pmu);
return err;
}
@@ -1122,7 +1068,8 @@ static int arm_pmu_hp_init(void)
ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_STARTING,
"perf/arm/pmu:starting",
- arm_perf_starting_cpu, NULL);
+ arm_perf_starting_cpu,
+ arm_perf_teardown_cpu);
if (ret)
pr_err("CPU hotplug notifier for ARM PMU could not be registered: %d\n",
ret);
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index 05a3eb447fc8..44f43fcf2524 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -105,12 +105,8 @@ struct arm_pmu {
void (*start)(struct arm_pmu *);
void (*stop)(struct arm_pmu *);
void (*reset)(void *);
- int (*request_irq)(struct arm_pmu *, irq_handler_t handler);
- void (*free_irq)(struct arm_pmu *);
int (*map_event)(struct perf_event *event);
int num_events;
- atomic_t active_events;
- struct mutex reserve_mutex;
u64 max_period;
bool secure_access; /* 32-bit ARM only */
#define ARMV8_PMUV3_MAX_COMMON_EVENTS 0x40

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