diff options
Diffstat (limited to 'drivers/perf/arm_pmu.c')
| -rw-r--r-- | drivers/perf/arm_pmu.c | 118 |
1 files changed, 115 insertions, 3 deletions
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index 8af1f900ea65..9ffa22814de3 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -13,6 +13,7 @@ #include <linux/bitmap.h> #include <linux/cpumask.h> +#include <linux/cpu_pm.h> #include <linux/export.h> #include <linux/kernel.h> #include <linux/of_device.h> @@ -321,10 +322,16 @@ validate_group(struct perf_event *event) return 0; } +static struct arm_pmu_platdata *armpmu_get_platdata(struct arm_pmu *armpmu) +{ + struct platform_device *pdev = armpmu->plat_device; + + return pdev ? dev_get_platdata(&pdev->dev) : NULL; +} + static irqreturn_t armpmu_dispatch_irq(int irq, void *dev) { struct arm_pmu *armpmu; - struct platform_device *plat_device; struct arm_pmu_platdata *plat; int ret; u64 start_clock, finish_clock; @@ -336,8 +343,8 @@ static irqreturn_t armpmu_dispatch_irq(int irq, void *dev) * dereference. */ armpmu = *(void **)dev; - plat_device = armpmu->plat_device; - plat = dev_get_platdata(&plat_device->dev); + + plat = armpmu_get_platdata(armpmu); start_clock = sched_clock(); if (plat && plat->handle_irq) @@ -718,6 +725,104 @@ static int cpu_pmu_notify(struct notifier_block *b, unsigned long action, return NOTIFY_OK; } +#ifdef CONFIG_CPU_PM +static void cpu_pm_pmu_setup(struct arm_pmu *armpmu, unsigned long cmd) +{ + struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events); + struct perf_event *event; + int idx; + + for (idx = 0; idx < armpmu->num_events; idx++) { + /* + * If the counter is not used skip it, there is no + * need of stopping/restarting it. + */ + if (!test_bit(idx, hw_events->used_mask)) + continue; + + event = hw_events->events[idx]; + + switch (cmd) { + case CPU_PM_ENTER: + /* + * Stop and update the counter + */ + armpmu_stop(event, PERF_EF_UPDATE); + break; + case CPU_PM_EXIT: + case CPU_PM_ENTER_FAILED: + /* + * Restore and enable the counter. + * armpmu_start() indirectly calls + * + * perf_event_update_userpage() + * + * that requires RCU read locking to be functional, + * wrap the call within RCU_NONIDLE to make the + * RCU subsystem aware this cpu is not idle from + * an RCU perspective for the armpmu_start() call + * duration. + */ + RCU_NONIDLE(armpmu_start(event, PERF_EF_RELOAD)); + break; + default: + break; + } + } +} + +static int cpu_pm_pmu_notify(struct notifier_block *b, unsigned long cmd, + void *v) +{ + struct arm_pmu *armpmu = container_of(b, struct arm_pmu, cpu_pm_nb); + struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events); + int enabled = bitmap_weight(hw_events->used_mask, armpmu->num_events); + + if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus)) + return NOTIFY_DONE; + + /* + * Always reset the PMU registers on power-up even if + * there are no events running. + */ + if (cmd == CPU_PM_EXIT && armpmu->reset) + armpmu->reset(armpmu); + + if (!enabled) + return NOTIFY_OK; + + switch (cmd) { + case CPU_PM_ENTER: + armpmu->stop(armpmu); + cpu_pm_pmu_setup(armpmu, cmd); + break; + case CPU_PM_EXIT: + cpu_pm_pmu_setup(armpmu, cmd); + case CPU_PM_ENTER_FAILED: + armpmu->start(armpmu); + break; + default: + return NOTIFY_DONE; + } + + return NOTIFY_OK; +} + +static int cpu_pm_pmu_register(struct arm_pmu *cpu_pmu) +{ + cpu_pmu->cpu_pm_nb.notifier_call = cpu_pm_pmu_notify; + return cpu_pm_register_notifier(&cpu_pmu->cpu_pm_nb); +} + +static void cpu_pm_pmu_unregister(struct arm_pmu *cpu_pmu) +{ + cpu_pm_unregister_notifier(&cpu_pmu->cpu_pm_nb); +} +#else +static inline int cpu_pm_pmu_register(struct arm_pmu *cpu_pmu) { return 0; } +static inline void cpu_pm_pmu_unregister(struct arm_pmu *cpu_pmu) { } +#endif + static int cpu_pmu_init(struct arm_pmu *cpu_pmu) { int err; @@ -733,6 +838,10 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu) if (err) goto out_hw_events; + err = cpu_pm_pmu_register(cpu_pmu); + if (err) + goto out_unregister; + for_each_possible_cpu(cpu) { struct pmu_hw_events *events = per_cpu_ptr(cpu_hw_events, cpu); raw_spin_lock_init(&events->pmu_lock); @@ -754,6 +863,8 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu) return 0; +out_unregister: + unregister_cpu_notifier(&cpu_pmu->hotplug_nb); out_hw_events: free_percpu(cpu_hw_events); return err; @@ -761,6 +872,7 @@ out_hw_events: static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu) { + cpu_pm_pmu_unregister(cpu_pmu); unregister_cpu_notifier(&cpu_pmu->hotplug_nb); free_percpu(cpu_pmu->hw_events); } |