diff options
Diffstat (limited to 'drivers/powercap/idle_inject.c')
| -rw-r--r-- | drivers/powercap/idle_inject.c | 65 |
1 files changed, 57 insertions, 8 deletions
diff --git a/drivers/powercap/idle_inject.c b/drivers/powercap/idle_inject.c index fe86a09e3b67..e18a2cc4e46a 100644 --- a/drivers/powercap/idle_inject.c +++ b/drivers/powercap/idle_inject.c @@ -63,13 +63,29 @@ struct idle_inject_thread { * @idle_duration_us: duration of CPU idle time to inject * @run_duration_us: duration of CPU run time to allow * @latency_us: max allowed latency + * @update: Optional callback deciding whether or not to skip idle + * injection in the given cycle. * @cpumask: mask of CPUs affected by idle injection + * + * This structure is used to define per instance idle inject device data. Each + * instance has an idle duration, a run duration and mask of CPUs to inject + * idle. + * + * Actual CPU idle time is injected by calling kernel scheduler interface + * play_idle_precise(). There is one optional callback that can be registered + * by calling idle_inject_register_full(): + * + * update() - This callback is invoked just before waking up CPUs to inject + * idle. If it returns false, CPUs are not woken up to inject idle in the given + * cycle. It also allows the caller to readjust the idle and run duration by + * calling idle_inject_set_duration() for the next cycle. */ struct idle_inject_device { struct hrtimer timer; unsigned int idle_duration_us; unsigned int run_duration_us; unsigned int latency_us; + bool (*update)(void); unsigned long cpumask[]; }; @@ -111,11 +127,12 @@ static enum hrtimer_restart idle_inject_timer_fn(struct hrtimer *timer) struct idle_inject_device *ii_dev = container_of(timer, struct idle_inject_device, timer); + if (!ii_dev->update || (ii_dev->update && ii_dev->update())) + idle_inject_wakeup(ii_dev); + duration_us = READ_ONCE(ii_dev->run_duration_us); duration_us += READ_ONCE(ii_dev->idle_duration_us); - idle_inject_wakeup(ii_dev); - hrtimer_forward_now(timer, ns_to_ktime(duration_us * NSEC_PER_USEC)); return HRTIMER_RESTART; @@ -155,11 +172,14 @@ void idle_inject_set_duration(struct idle_inject_device *ii_dev, unsigned int run_duration_us, unsigned int idle_duration_us) { - if (run_duration_us && idle_duration_us) { + if (run_duration_us + idle_duration_us) { WRITE_ONCE(ii_dev->run_duration_us, run_duration_us); WRITE_ONCE(ii_dev->idle_duration_us, idle_duration_us); } + if (!run_duration_us) + pr_debug("CPU is forced to 100 percent idle\n"); } +EXPORT_SYMBOL_NS_GPL(idle_inject_set_duration, IDLE_INJECT); /** * idle_inject_get_duration - idle and run duration retrieval helper @@ -174,6 +194,7 @@ void idle_inject_get_duration(struct idle_inject_device *ii_dev, *run_duration_us = READ_ONCE(ii_dev->run_duration_us); *idle_duration_us = READ_ONCE(ii_dev->idle_duration_us); } +EXPORT_SYMBOL_NS_GPL(idle_inject_get_duration, IDLE_INJECT); /** * idle_inject_set_latency - set the maximum latency allowed @@ -185,6 +206,7 @@ void idle_inject_set_latency(struct idle_inject_device *ii_dev, { WRITE_ONCE(ii_dev->latency_us, latency_us); } +EXPORT_SYMBOL_NS_GPL(idle_inject_set_latency, IDLE_INJECT); /** * idle_inject_start - start idle injections @@ -201,7 +223,7 @@ int idle_inject_start(struct idle_inject_device *ii_dev) unsigned int idle_duration_us = READ_ONCE(ii_dev->idle_duration_us); unsigned int run_duration_us = READ_ONCE(ii_dev->run_duration_us); - if (!idle_duration_us || !run_duration_us) + if (!(idle_duration_us + run_duration_us)) return -EINVAL; pr_debug("Starting injecting idle cycles on CPUs '%*pbl'\n", @@ -216,6 +238,7 @@ int idle_inject_start(struct idle_inject_device *ii_dev) return 0; } +EXPORT_SYMBOL_NS_GPL(idle_inject_start, IDLE_INJECT); /** * idle_inject_stop - stops idle injections @@ -262,6 +285,7 @@ void idle_inject_stop(struct idle_inject_device *ii_dev) cpu_hotplug_enable(); } +EXPORT_SYMBOL_NS_GPL(idle_inject_stop, IDLE_INJECT); /** * idle_inject_setup - prepare the current task for idle injection @@ -290,17 +314,22 @@ static int idle_inject_should_run(unsigned int cpu) } /** - * idle_inject_register - initialize idle injection on a set of CPUs + * idle_inject_register_full - initialize idle injection on a set of CPUs * @cpumask: CPUs to be affected by idle injection + * @update: This callback is called just before waking up CPUs to inject + * idle * * This function creates an idle injection control device structure for the - * given set of CPUs and initializes the timer associated with it. It does not - * start any injection cycles. + * given set of CPUs and initializes the timer associated with it. This + * function also allows to register update()callback. + * It does not start any injection cycles. * * Return: NULL if memory allocation fails, idle injection control device * pointer on success. */ -struct idle_inject_device *idle_inject_register(struct cpumask *cpumask) + +struct idle_inject_device *idle_inject_register_full(struct cpumask *cpumask, + bool (*update)(void)) { struct idle_inject_device *ii_dev; int cpu, cpu_rb; @@ -313,6 +342,7 @@ struct idle_inject_device *idle_inject_register(struct cpumask *cpumask) hrtimer_init(&ii_dev->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); ii_dev->timer.function = idle_inject_timer_fn; ii_dev->latency_us = UINT_MAX; + ii_dev->update = update; for_each_cpu(cpu, to_cpumask(ii_dev->cpumask)) { @@ -337,6 +367,24 @@ out_rollback: return NULL; } +EXPORT_SYMBOL_NS_GPL(idle_inject_register_full, IDLE_INJECT); + +/** + * idle_inject_register - initialize idle injection on a set of CPUs + * @cpumask: CPUs to be affected by idle injection + * + * This function creates an idle injection control device structure for the + * given set of CPUs and initializes the timer associated with it. It does not + * start any injection cycles. + * + * Return: NULL if memory allocation fails, idle injection control device + * pointer on success. + */ +struct idle_inject_device *idle_inject_register(struct cpumask *cpumask) +{ + return idle_inject_register_full(cpumask, NULL); +} +EXPORT_SYMBOL_NS_GPL(idle_inject_register, IDLE_INJECT); /** * idle_inject_unregister - unregister idle injection control device @@ -357,6 +405,7 @@ void idle_inject_unregister(struct idle_inject_device *ii_dev) kfree(ii_dev); } +EXPORT_SYMBOL_NS_GPL(idle_inject_unregister, IDLE_INJECT); static struct smp_hotplug_thread idle_inject_threads = { .store = &idle_inject_thread.tsk, |