diff options
Diffstat (limited to 'drivers/perf')
| -rw-r--r-- | drivers/perf/arm_pmu.c | 120 |
1 files changed, 118 insertions, 2 deletions
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index 166637f29..f70090897 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> @@ -710,6 +711,104 @@ 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; @@ -725,6 +824,10 @@ 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); @@ -746,6 +849,8 @@ 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; @@ -753,6 +858,7 @@ 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); } @@ -889,6 +995,15 @@ int arm_pmu_device_probe(struct platform_device *pdev, if (node && (of_id = of_match_node(of_table, pdev->dev.of_node))) { init_fn = of_id->data; + pmu->secure_access = of_property_read_bool(pdev->dev.of_node, + "secure-reg-access"); + + /* arm64 systems boot only as non-secure */ + if (IS_ENABLED(CONFIG_ARM64) && pmu->secure_access) { + pr_warn("ignoring \"secure-reg-access\" property for arm64\n"); + pmu->secure_access = false; + } + ret = of_pmu_irq_cfg(pmu); if (!ret) ret = init_fn(pmu); @@ -898,7 +1013,7 @@ int arm_pmu_device_probe(struct platform_device *pdev, } if (ret) { - pr_info("failed to probe PMU!\n"); + pr_info("%s: failed to probe PMU!\n", of_node_full_name(node)); goto out_free; } @@ -918,7 +1033,8 @@ int arm_pmu_device_probe(struct platform_device *pdev, out_destroy: cpu_pmu_destroy(pmu); out_free: - pr_info("failed to register PMU devices!\n"); + pr_info("%s: failed to register PMU devices!\n", + of_node_full_name(node)); kfree(pmu); return ret; } |