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Diffstat (limited to 'arch/arm64/kernel/perf_event.c')
-rw-r--r--arch/arm64/kernel/perf_event.c50
1 files changed, 28 insertions, 22 deletions
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 53df84b2a07f..4ee1228d29eb 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -670,6 +670,28 @@ static void armv8pmu_disable_event(struct perf_event *event)
raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
}
+static void armv8pmu_start(struct arm_pmu *cpu_pmu)
+{
+ unsigned long flags;
+ struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
+
+ raw_spin_lock_irqsave(&events->pmu_lock, flags);
+ /* Enable all counters */
+ armv8pmu_pmcr_write(armv8pmu_pmcr_read() | ARMV8_PMU_PMCR_E);
+ raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
+}
+
+static void armv8pmu_stop(struct arm_pmu *cpu_pmu)
+{
+ unsigned long flags;
+ struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
+
+ raw_spin_lock_irqsave(&events->pmu_lock, flags);
+ /* Disable all counters */
+ armv8pmu_pmcr_write(armv8pmu_pmcr_read() & ~ARMV8_PMU_PMCR_E);
+ raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
+}
+
static irqreturn_t armv8pmu_handle_irq(int irq_num, void *dev)
{
u32 pmovsr;
@@ -695,6 +717,11 @@ static irqreturn_t armv8pmu_handle_irq(int irq_num, void *dev)
*/
regs = get_irq_regs();
+ /*
+ * Stop the PMU while processing the counter overflows
+ * to prevent skews in group events.
+ */
+ armv8pmu_stop(cpu_pmu);
for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
struct perf_event *event = cpuc->events[idx];
struct hw_perf_event *hwc;
@@ -719,6 +746,7 @@ static irqreturn_t armv8pmu_handle_irq(int irq_num, void *dev)
if (perf_event_overflow(event, &data, regs))
cpu_pmu->disable(event);
}
+ armv8pmu_start(cpu_pmu);
/*
* Handle the pending perf events.
@@ -732,28 +760,6 @@ static irqreturn_t armv8pmu_handle_irq(int irq_num, void *dev)
return IRQ_HANDLED;
}
-static void armv8pmu_start(struct arm_pmu *cpu_pmu)
-{
- unsigned long flags;
- struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
-
- raw_spin_lock_irqsave(&events->pmu_lock, flags);
- /* Enable all counters */
- armv8pmu_pmcr_write(armv8pmu_pmcr_read() | ARMV8_PMU_PMCR_E);
- raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
-}
-
-static void armv8pmu_stop(struct arm_pmu *cpu_pmu)
-{
- unsigned long flags;
- struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
-
- raw_spin_lock_irqsave(&events->pmu_lock, flags);
- /* Disable all counters */
- armv8pmu_pmcr_write(armv8pmu_pmcr_read() & ~ARMV8_PMU_PMCR_E);
- raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
-}
-
static int armv8pmu_get_event_idx(struct pmu_hw_events *cpuc,
struct perf_event *event)
{