arm_pmu: note IRQs and PMUs per-cpu
To support ACPI systems, we need to request IRQs before we know the
associated PMU, and thus we need some percpu variable that the IRQ
handler can find the PMU from.
As we're going to request IRQs without the PMU, we can't rely on the
arm_pmu::active_irqs mask, and similarly need to track requested IRQs
with a percpu variable.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[will: made armpmu_count_irq_users static]
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 72118e6..2b2af35 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -25,6 +25,9 @@
#include <asm/irq_regs.h>
+static DEFINE_PER_CPU(struct arm_pmu *, cpu_armpmu);
+static DEFINE_PER_CPU(int, cpu_irq);
+
static int
armpmu_map_cache_event(const unsigned (*cache_map)
[PERF_COUNT_HW_CACHE_MAX]
@@ -332,6 +335,8 @@
* dereference.
*/
armpmu = *(void **)dev;
+ if (WARN_ON_ONCE(!armpmu))
+ return IRQ_NONE;
start_clock = sched_clock();
ret = armpmu->handle_irq(irq, armpmu);
@@ -517,29 +522,45 @@
}
EXPORT_SYMBOL_GPL(perf_num_counters);
+static int armpmu_count_irq_users(const int irq)
+{
+ int cpu, count = 0;
+
+ for_each_possible_cpu(cpu) {
+ if (per_cpu(cpu_irq, cpu) == irq)
+ count++;
+ }
+
+ return count;
+}
+
+void armpmu_free_cpu_irq(int irq, int cpu)
+{
+ if (per_cpu(cpu_irq, cpu) == 0)
+ return;
+ if (WARN_ON(irq != per_cpu(cpu_irq, cpu)))
+ return;
+
+ if (!irq_is_percpu_devid(irq))
+ free_irq(irq, per_cpu_ptr(&cpu_armpmu, cpu));
+ else if (armpmu_count_irq_users(irq) == 1)
+ free_percpu_irq(irq, &cpu_armpmu);
+
+ per_cpu(cpu_irq, cpu) = 0;
+}
+
void armpmu_free_irq(struct arm_pmu *armpmu, int cpu)
{
struct pmu_hw_events __percpu *hw_events = armpmu->hw_events;
int irq = per_cpu(hw_events->irq, cpu);
- if (!cpumask_test_and_clear_cpu(cpu, &armpmu->active_irqs))
- return;
-
- if (irq_is_percpu_devid(irq)) {
- free_percpu_irq(irq, &hw_events->percpu_pmu);
- cpumask_clear(&armpmu->active_irqs);
- return;
- }
-
- free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, cpu));
+ armpmu_free_cpu_irq(irq, cpu);
}
-int armpmu_request_irq(struct arm_pmu *armpmu, int cpu)
+int armpmu_request_cpu_irq(int irq, int cpu)
{
int err = 0;
- struct pmu_hw_events __percpu *hw_events = armpmu->hw_events;
const irq_handler_t handler = armpmu_dispatch_irq;
- int irq = per_cpu(hw_events->irq, cpu);
if (!irq)
return 0;
@@ -560,16 +581,16 @@
irq_set_status_flags(irq, IRQ_NOAUTOEN);
err = request_irq(irq, handler, irq_flags, "arm-pmu",
- per_cpu_ptr(&hw_events->percpu_pmu, cpu));
- } else if (cpumask_empty(&armpmu->active_irqs)) {
+ per_cpu_ptr(&cpu_armpmu, cpu));
+ } else if (armpmu_count_irq_users(irq) == 0) {
err = request_percpu_irq(irq, handler, "arm-pmu",
- &hw_events->percpu_pmu);
+ &cpu_armpmu);
}
if (err)
goto err_out;
- cpumask_set_cpu(cpu, &armpmu->active_irqs);
+ per_cpu(cpu_irq, cpu) = irq;
return 0;
err_out:
@@ -577,6 +598,16 @@
return err;
}
+int armpmu_request_irq(struct arm_pmu *armpmu, int cpu)
+{
+ struct pmu_hw_events __percpu *hw_events = armpmu->hw_events;
+ int irq = per_cpu(hw_events->irq, cpu);
+ if (!irq)
+ return 0;
+
+ return armpmu_request_cpu_irq(irq, cpu);
+}
+
static int armpmu_get_cpu_irq(struct arm_pmu *pmu, int cpu)
{
struct pmu_hw_events __percpu *hw_events = pmu->hw_events;
@@ -599,6 +630,8 @@
if (pmu->reset)
pmu->reset(pmu);
+ per_cpu(cpu_armpmu, cpu) = pmu;
+
irq = armpmu_get_cpu_irq(pmu, cpu);
if (irq) {
if (irq_is_percpu_devid(irq))
@@ -626,6 +659,8 @@
disable_irq(irq);
}
+ per_cpu(cpu_armpmu, cpu) = NULL;
+
return 0;
}
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index 1f8bb83..feec9e7 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -75,7 +75,6 @@
struct arm_pmu {
struct pmu pmu;
- cpumask_t active_irqs;
cpumask_t supported_cpus;
char *name;
irqreturn_t (*handle_irq)(int irq_num, void *dev);