diff --git a/arch/arm64/kernel/perf_debug.c b/arch/arm64/kernel/perf_debug.c index 08e93a71fa7d..4828cfbca654 100644 --- a/arch/arm64/kernel/perf_debug.c +++ b/arch/arm64/kernel/perf_debug.c @@ -30,6 +30,7 @@ static char *descriptions = " 7 Perf: arm64: Update PMU force reset\n" "10 Perf: arm64: tracectr: initialize counts after hotplug\n" "11 Perf: arm64: Refine disable/enable in tracecounters\n" + "12 Perf: arm64: fix disable of pmu irq during hotplug\n" "15 Perf: arm64: make debug dir handle exportable\n" "16 Perf: arm64: add perf trace user\n" "17 Perf: arm64: add support for kryo pmu\n" diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index bb6f8bdbf01b..d8708fe77317 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -370,6 +370,8 @@ armpmu_reserve_hardware(struct arm_pmu *armpmu) return err; } + armpmu->pmu_state = ARM_PMU_STATE_RUNNING; + return 0; } @@ -630,6 +632,14 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu) struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events; irqs = min(pmu_device->num_resources, num_possible_cpus()); + if (!irqs) + return; + + /* + * If a cpu comes online during this function, do not enable its irq. + * If a cpu goes offline, it should disable its irq. + */ + cpu_pmu->pmu_state = ARM_PMU_STATE_GOING_DOWN; irq = platform_get_irq(pmu_device, 0); if (irq >= 0 && irq_is_percpu(irq)) { @@ -649,6 +659,7 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu) free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, cpu)); } } + cpu_pmu->pmu_state = ARM_PMU_STATE_OFF; } static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler) @@ -766,7 +777,6 @@ static int cpu_pmu_notify(struct notifier_block *b, unsigned long action, struct arm_pmu *cpu_pmu = container_of(b, struct arm_pmu, hotplug_nb); int irq; struct pmu *pmu; - int perf_running; unsigned long masked_action = action & ~CPU_TASKS_FROZEN; int ret = NOTIFY_DONE; @@ -783,13 +793,12 @@ static int cpu_pmu_notify(struct notifier_block *b, unsigned long action, if (!cpumask_test_cpu(cpu, &cpu_pmu->supported_cpus)) return NOTIFY_DONE; - perf_running = atomic_read(&cpu_pmu->active_events); switch (masked_action) { case CPU_DOWN_PREPARE: if (cpu_pmu->save_pm_registers) smp_call_function_single(cpu, cpu_pmu->save_pm_registers, hcpu, 1); - if (perf_running) { + if (cpu_pmu->pmu_state != ARM_PMU_STATE_OFF) { if (cpu_has_active_perf(cpu, cpu_pmu)) smp_call_function_single(cpu, armpmu_update_counters, cpu_pmu, 1); @@ -808,7 +817,7 @@ static int cpu_pmu_notify(struct notifier_block *b, unsigned long action, cpu_pmu->reset(NULL); if (cpu_pmu->restore_pm_registers) cpu_pmu->restore_pm_registers(hcpu); - if (perf_running) { + if (cpu_pmu->pmu_state == ARM_PMU_STATE_RUNNING) { /* Arm the PMU IRQ before appearing. */ if (cpu_pmu->plat_device) { irq = cpu_pmu->percpu_irq; diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h index 12456debc693..6ebc90027fb3 100644 --- a/include/linux/perf/arm_pmu.h +++ b/include/linux/perf/arm_pmu.h @@ -51,6 +51,12 @@ struct arm_pmu_platdata { }, \ } +enum arm_pmu_state { + ARM_PMU_STATE_OFF = 0, + ARM_PMU_STATE_GOING_DOWN, + ARM_PMU_STATE_RUNNING, +}; + /* The events for a given PMU register set. */ struct pmu_hw_events { /* @@ -103,6 +109,7 @@ struct arm_pmu { void (*free_irq)(struct arm_pmu *); int (*map_event)(struct perf_event *event); int num_events; + int pmu_state; int percpu_irq; atomic_t active_events; struct mutex reserve_mutex;