diff options
Diffstat (limited to 'drivers/base/power/wakeup.c')
| -rw-r--r-- | drivers/base/power/wakeup.c | 613 |
1 files changed, 535 insertions, 78 deletions
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c index eb594facfc3f..71c5528e1c35 100644 --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -11,7 +11,12 @@ #include <linux/sched.h> #include <linux/capability.h> #include <linux/suspend.h> -#include <linux/pm.h> +#include <linux/seq_file.h> +#include <linux/debugfs.h> + +#include "power.h" + +#define TIMEOUT 100 /* * If set, the suspend/hibernate code will abort transitions to a sleep state @@ -20,18 +25,244 @@ bool events_check_enabled; /* The counter of registered wakeup events. */ -static unsigned long event_count; +static atomic_t event_count = ATOMIC_INIT(0); /* A preserved old value of event_count. */ -static unsigned long saved_event_count; +static unsigned int saved_count; /* The counter of wakeup events being processed. */ -static unsigned long events_in_progress; +static atomic_t events_in_progress = ATOMIC_INIT(0); static DEFINE_SPINLOCK(events_lock); static void pm_wakeup_timer_fn(unsigned long data); -static DEFINE_TIMER(events_timer, pm_wakeup_timer_fn, 0, 0); -static unsigned long events_timer_expires; +static LIST_HEAD(wakeup_sources); + +/** + * wakeup_source_create - Create a struct wakeup_source object. + * @name: Name of the new wakeup source. + */ +struct wakeup_source *wakeup_source_create(const char *name) +{ + struct wakeup_source *ws; + + ws = kzalloc(sizeof(*ws), GFP_KERNEL); + if (!ws) + return NULL; + + spin_lock_init(&ws->lock); + if (name) + ws->name = kstrdup(name, GFP_KERNEL); + + return ws; +} +EXPORT_SYMBOL_GPL(wakeup_source_create); + +/** + * wakeup_source_destroy - Destroy a struct wakeup_source object. + * @ws: Wakeup source to destroy. + */ +void wakeup_source_destroy(struct wakeup_source *ws) +{ + if (!ws) + return; + + spin_lock_irq(&ws->lock); + while (ws->active) { + spin_unlock_irq(&ws->lock); + + schedule_timeout_interruptible(msecs_to_jiffies(TIMEOUT)); + + spin_lock_irq(&ws->lock); + } + spin_unlock_irq(&ws->lock); + + kfree(ws->name); + kfree(ws); +} +EXPORT_SYMBOL_GPL(wakeup_source_destroy); + +/** + * wakeup_source_add - Add given object to the list of wakeup sources. + * @ws: Wakeup source object to add to the list. + */ +void wakeup_source_add(struct wakeup_source *ws) +{ + if (WARN_ON(!ws)) + return; + + setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws); + ws->active = false; + + spin_lock_irq(&events_lock); + list_add_rcu(&ws->entry, &wakeup_sources); + spin_unlock_irq(&events_lock); + synchronize_rcu(); +} +EXPORT_SYMBOL_GPL(wakeup_source_add); + +/** + * wakeup_source_remove - Remove given object from the wakeup sources list. + * @ws: Wakeup source object to remove from the list. + */ +void wakeup_source_remove(struct wakeup_source *ws) +{ + if (WARN_ON(!ws)) + return; + + spin_lock_irq(&events_lock); + list_del_rcu(&ws->entry); + spin_unlock_irq(&events_lock); + synchronize_rcu(); +} +EXPORT_SYMBOL_GPL(wakeup_source_remove); + +/** + * wakeup_source_register - Create wakeup source and add it to the list. + * @name: Name of the wakeup source to register. + */ +struct wakeup_source *wakeup_source_register(const char *name) +{ + struct wakeup_source *ws; + + ws = wakeup_source_create(name); + if (ws) + wakeup_source_add(ws); + + return ws; +} +EXPORT_SYMBOL_GPL(wakeup_source_register); + +/** + * wakeup_source_unregister - Remove wakeup source from the list and remove it. + * @ws: Wakeup source object to unregister. + */ +void wakeup_source_unregister(struct wakeup_source *ws) +{ + wakeup_source_remove(ws); + wakeup_source_destroy(ws); +} +EXPORT_SYMBOL_GPL(wakeup_source_unregister); + +/** + * device_wakeup_attach - Attach a wakeup source object to a device object. + * @dev: Device to handle. + * @ws: Wakeup source object to attach to @dev. + * + * This causes @dev to be treated as a wakeup device. + */ +static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws) +{ + spin_lock_irq(&dev->power.lock); + if (dev->power.wakeup) { + spin_unlock_irq(&dev->power.lock); + return -EEXIST; + } + dev->power.wakeup = ws; + spin_unlock_irq(&dev->power.lock); + return 0; +} + +/** + * device_wakeup_enable - Enable given device to be a wakeup source. + * @dev: Device to handle. + * + * Create a wakeup source object, register it and attach it to @dev. + */ +int device_wakeup_enable(struct device *dev) +{ + struct wakeup_source *ws; + int ret; + + if (!dev || !dev->power.can_wakeup) + return -EINVAL; + + ws = wakeup_source_register(dev_name(dev)); + if (!ws) + return -ENOMEM; + + ret = device_wakeup_attach(dev, ws); + if (ret) + wakeup_source_unregister(ws); + + return ret; +} +EXPORT_SYMBOL_GPL(device_wakeup_enable); + +/** + * device_wakeup_detach - Detach a device's wakeup source object from it. + * @dev: Device to detach the wakeup source object from. + * + * After it returns, @dev will not be treated as a wakeup device any more. + */ +static struct wakeup_source *device_wakeup_detach(struct device *dev) +{ + struct wakeup_source *ws; + + spin_lock_irq(&dev->power.lock); + ws = dev->power.wakeup; + dev->power.wakeup = NULL; + spin_unlock_irq(&dev->power.lock); + return ws; +} + +/** + * device_wakeup_disable - Do not regard a device as a wakeup source any more. + * @dev: Device to handle. + * + * Detach the @dev's wakeup source object from it, unregister this wakeup source + * object and destroy it. + */ +int device_wakeup_disable(struct device *dev) +{ + struct wakeup_source *ws; + + if (!dev || !dev->power.can_wakeup) + return -EINVAL; + + ws = device_wakeup_detach(dev); + if (ws) + wakeup_source_unregister(ws); + + return 0; +} +EXPORT_SYMBOL_GPL(device_wakeup_disable); + +/** + * device_init_wakeup - Device wakeup initialization. + * @dev: Device to handle. + * @enable: Whether or not to enable @dev as a wakeup device. + * + * By default, most devices should leave wakeup disabled. The exceptions are + * devices that everyone expects to be wakeup sources: keyboards, power buttons, + * possibly network interfaces, etc. + */ +int device_init_wakeup(struct device *dev, bool enable) +{ + int ret = 0; + + if (enable) { + device_set_wakeup_capable(dev, true); + ret = device_wakeup_enable(dev); + } else { + device_set_wakeup_capable(dev, false); + } + + return ret; +} +EXPORT_SYMBOL_GPL(device_init_wakeup); + +/** + * device_set_wakeup_enable - Enable or disable a device to wake up the system. + * @dev: Device to handle. + */ +int device_set_wakeup_enable(struct device *dev, bool enable) +{ + if (!dev || !dev->power.can_wakeup) + return -EINVAL; + + return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev); +} +EXPORT_SYMBOL_GPL(device_set_wakeup_enable); /* * The functions below use the observation that each wakeup event starts a @@ -55,118 +286,259 @@ static unsigned long events_timer_expires; * knowledge, however, may not be available to it, so it can simply specify time * to wait before the system can be suspended and pass it as the second * argument of pm_wakeup_event(). + * + * It is valid to call pm_relax() after pm_wakeup_event(), in which case the + * "no suspend" period will be ended either by the pm_relax(), or by the timer + * function executed when the timer expires, whichever comes first. */ /** + * wakup_source_activate - Mark given wakeup source as active. + * @ws: Wakeup source to handle. + * + * Update the @ws' statistics and, if @ws has just been activated, notify the PM + * core of the event by incrementing the counter of of wakeup events being + * processed. + */ +static void wakeup_source_activate(struct wakeup_source *ws) +{ + ws->active = true; + ws->active_count++; + ws->timer_expires = jiffies; + ws->last_time = ktime_get(); + + atomic_inc(&events_in_progress); +} + +/** + * __pm_stay_awake - Notify the PM core of a wakeup event. + * @ws: Wakeup source object associated with the source of the event. + * + * It is safe to call this function from interrupt context. + */ +void __pm_stay_awake(struct wakeup_source *ws) +{ + unsigned long flags; + + if (!ws) + return; + + spin_lock_irqsave(&ws->lock, flags); + ws->event_count++; + if (!ws->active) + wakeup_source_activate(ws); + spin_unlock_irqrestore(&ws->lock, flags); +} +EXPORT_SYMBOL_GPL(__pm_stay_awake); + +/** * pm_stay_awake - Notify the PM core that a wakeup event is being processed. * @dev: Device the wakeup event is related to. * - * Notify the PM core of a wakeup event (signaled by @dev) by incrementing the - * counter of wakeup events being processed. If @dev is not NULL, the counter - * of wakeup events related to @dev is incremented too. + * Notify the PM core of a wakeup event (signaled by @dev) by calling + * __pm_stay_awake for the @dev's wakeup source object. * * Call this function after detecting of a wakeup event if pm_relax() is going * to be called directly after processing the event (and possibly passing it to * user space for further processing). - * - * It is safe to call this function from interrupt context. */ void pm_stay_awake(struct device *dev) { unsigned long flags; - spin_lock_irqsave(&events_lock, flags); - if (dev) - dev->power.wakeup_count++; + if (!dev) + return; - events_in_progress++; - spin_unlock_irqrestore(&events_lock, flags); + spin_lock_irqsave(&dev->power.lock, flags); + __pm_stay_awake(dev->power.wakeup); + spin_unlock_irqrestore(&dev->power.lock, flags); } +EXPORT_SYMBOL_GPL(pm_stay_awake); /** - * pm_relax - Notify the PM core that processing of a wakeup event has ended. + * wakup_source_deactivate - Mark given wakeup source as inactive. + * @ws: Wakeup source to handle. * - * Notify the PM core that a wakeup event has been processed by decrementing - * the counter of wakeup events being processed and incrementing the counter - * of registered wakeup events. + * Update the @ws' statistics and notify the PM core that the wakeup source has + * become inactive by decrementing the counter of wakeup events being processed + * and incrementing the counter of registered wakeup events. + */ +static void wakeup_source_deactivate(struct wakeup_source *ws) +{ + ktime_t duration; + ktime_t now; + + ws->relax_count++; + /* + * __pm_relax() may be called directly or from a timer function. + * If it is called directly right after the timer function has been + * started, but before the timer function calls __pm_relax(), it is + * possible that __pm_stay_awake() will be called in the meantime and + * will set ws->active. Then, ws->active may be cleared immediately + * by the __pm_relax() called from the timer function, but in such a + * case ws->relax_count will be different from ws->active_count. + */ + if (ws->relax_count != ws->active_count) { + ws->relax_count--; + return; + } + + ws->active = false; + + now = ktime_get(); + duration = ktime_sub(now, ws->last_time); + ws->total_time = ktime_add(ws->total_time, duration); + if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time)) + ws->max_time = duration; + + del_timer(&ws->timer); + + /* + * event_count has to be incremented before events_in_progress is + * modified, so that the callers of pm_check_wakeup_events() and + * pm_save_wakeup_count() don't see the old value of event_count and + * events_in_progress equal to zero at the same time. + */ + atomic_inc(&event_count); + smp_mb__before_atomic_dec(); + atomic_dec(&events_in_progress); +} + +/** + * __pm_relax - Notify the PM core that processing of a wakeup event has ended. + * @ws: Wakeup source object associated with the source of the event. * * Call this function for wakeup events whose processing started with calling - * pm_stay_awake(). + * __pm_stay_awake(). * * It is safe to call it from interrupt context. */ -void pm_relax(void) +void __pm_relax(struct wakeup_source *ws) { unsigned long flags; - spin_lock_irqsave(&events_lock, flags); - if (events_in_progress) { - events_in_progress--; - event_count++; - } - spin_unlock_irqrestore(&events_lock, flags); + if (!ws) + return; + + spin_lock_irqsave(&ws->lock, flags); + if (ws->active) + wakeup_source_deactivate(ws); + spin_unlock_irqrestore(&ws->lock, flags); +} +EXPORT_SYMBOL_GPL(__pm_relax); + +/** + * pm_relax - Notify the PM core that processing of a wakeup event has ended. + * @dev: Device that signaled the event. + * + * Execute __pm_relax() for the @dev's wakeup source object. + */ +void pm_relax(struct device *dev) +{ + unsigned long flags; + + if (!dev) + return; + + spin_lock_irqsave(&dev->power.lock, flags); + __pm_relax(dev->power.wakeup); + spin_unlock_irqrestore(&dev->power.lock, flags); } +EXPORT_SYMBOL_GPL(pm_relax); /** * pm_wakeup_timer_fn - Delayed finalization of a wakeup event. + * @data: Address of the wakeup source object associated with the event source. * - * Decrease the counter of wakeup events being processed after it was increased - * by pm_wakeup_event(). + * Call __pm_relax() for the wakeup source whose address is stored in @data. */ static void pm_wakeup_timer_fn(unsigned long data) { + __pm_relax((struct wakeup_source *)data); +} + +/** + * __pm_wakeup_event - Notify the PM core of a wakeup event. + * @ws: Wakeup source object associated with the event source. + * @msec: Anticipated event processing time (in milliseconds). + * + * Notify the PM core of a wakeup event whose source is @ws that will take + * approximately @msec milliseconds to be processed by the kernel. If @ws is + * not active, activate it. If @msec is nonzero, set up the @ws' timer to + * execute pm_wakeup_timer_fn() in future. + * + * It is safe to call this function from interrupt context. + */ +void __pm_wakeup_event(struct wakeup_source *ws, unsigned int msec) +{ unsigned long flags; + unsigned long expires; - spin_lock_irqsave(&events_lock, flags); - if (events_timer_expires - && time_before_eq(events_timer_expires, jiffies)) { - events_in_progress--; - events_timer_expires = 0; + if (!ws) + return; + + spin_lock_irqsave(&ws->lock, flags); + + ws->event_count++; + if (!ws->active) + wakeup_source_activate(ws); + + if (!msec) { + wakeup_source_deactivate(ws); + goto unlock; } - spin_unlock_irqrestore(&events_lock, flags); + + expires = jiffies + msecs_to_jiffies(msec); + if (!expires) + expires = 1; + + if (time_after(expires, ws->timer_expires)) { + mod_timer(&ws->timer, expires); + ws->timer_expires = expires; + } + + unlock: + spin_unlock_irqrestore(&ws->lock, flags); } +EXPORT_SYMBOL_GPL(__pm_wakeup_event); + /** * pm_wakeup_event - Notify the PM core of a wakeup event. * @dev: Device the wakeup event is related to. * @msec: Anticipated event processing time (in milliseconds). * - * Notify the PM core of a wakeup event (signaled by @dev) that will take - * approximately @msec milliseconds to be processed by the kernel. Increment - * the counter of registered wakeup events and (if @msec is nonzero) set up - * the wakeup events timer to execute pm_wakeup_timer_fn() in future (if the - * timer has not been set up already, increment the counter of wakeup events - * being processed). If @dev is not NULL, the counter of wakeup events related - * to @dev is incremented too. - * - * It is safe to call this function from interrupt context. + * Call __pm_wakeup_event() for the @dev's wakeup source object. */ void pm_wakeup_event(struct device *dev, unsigned int msec) { unsigned long flags; - spin_lock_irqsave(&events_lock, flags); - event_count++; - if (dev) - dev->power.wakeup_count++; - - if (msec) { - unsigned long expires; + if (!dev) + return; - expires = jiffies + msecs_to_jiffies(msec); - if (!expires) - expires = 1; + spin_lock_irqsave(&dev->power.lock, flags); + __pm_wakeup_event(dev->power.wakeup, msec); + spin_unlock_irqrestore(&dev->power.lock, flags); +} +EXPORT_SYMBOL_GPL(pm_wakeup_event); - if (!events_timer_expires - || time_after(expires, events_timer_expires)) { - if (!events_timer_expires) - events_in_progress++; +/** + * pm_wakeup_update_hit_counts - Update hit counts of all active wakeup sources. + */ +static void pm_wakeup_update_hit_counts(void) +{ + unsigned long flags; + struct wakeup_source *ws; - mod_timer(&events_timer, expires); - events_timer_expires = expires; - } + rcu_read_lock(); + list_for_each_entry_rcu(ws, &wakeup_sources, entry) { + spin_lock_irqsave(&ws->lock, flags); + if (ws->active) + ws->hit_count++; + spin_unlock_irqrestore(&ws->lock, flags); } - spin_unlock_irqrestore(&events_lock, flags); + rcu_read_unlock(); } /** @@ -184,10 +556,13 @@ bool pm_check_wakeup_events(void) spin_lock_irqsave(&events_lock, flags); if (events_check_enabled) { - ret = (event_count == saved_event_count) && !events_in_progress; + ret = ((unsigned int)atomic_read(&event_count) == saved_count) + && !atomic_read(&events_in_progress); events_check_enabled = ret; } spin_unlock_irqrestore(&events_lock, flags); + if (!ret) + pm_wakeup_update_hit_counts(); return ret; } @@ -202,24 +577,20 @@ bool pm_check_wakeup_events(void) * drop down to zero has been interrupted by a signal (and the current number * of wakeup events being processed is still nonzero). Otherwise return true. */ -bool pm_get_wakeup_count(unsigned long *count) +bool pm_get_wakeup_count(unsigned int *count) { bool ret; - spin_lock_irq(&events_lock); if (capable(CAP_SYS_ADMIN)) events_check_enabled = false; - while (events_in_progress && !signal_pending(current)) { - spin_unlock_irq(&events_lock); - - schedule_timeout_interruptible(msecs_to_jiffies(100)); - - spin_lock_irq(&events_lock); + while (atomic_read(&events_in_progress) && !signal_pending(current)) { + pm_wakeup_update_hit_counts(); + schedule_timeout_interruptible(msecs_to_jiffies(TIMEOUT)); } - *count = event_count; - ret = !events_in_progress; - spin_unlock_irq(&events_lock); + + ret = !atomic_read(&events_in_progress); + *count = atomic_read(&event_count); return ret; } @@ -232,16 +603,102 @@ bool pm_get_wakeup_count(unsigned long *count) * old number of registered wakeup events to be used by pm_check_wakeup_events() * and return true. Otherwise return false. */ -bool pm_save_wakeup_count(unsigned long count) +bool pm_save_wakeup_count(unsigned int count) { bool ret = false; spin_lock_irq(&events_lock); - if (count == event_count && !events_in_progress) { - saved_event_count = count; + if (count == (unsigned int)atomic_read(&event_count) + && !atomic_read(&events_in_progress)) { + saved_count = count; events_check_enabled = true; ret = true; } spin_unlock_irq(&events_lock); + if (!ret) + pm_wakeup_update_hit_counts(); + return ret; +} + +static struct dentry *wakeup_sources_stats_dentry; + +/** + * print_wakeup_source_stats - Print wakeup source statistics information. + * @m: seq_file to print the statistics into. + * @ws: Wakeup source object to print the statistics for. + */ +static int print_wakeup_source_stats(struct seq_file *m, + struct wakeup_source *ws) +{ + unsigned long flags; + ktime_t total_time; + ktime_t max_time; + unsigned long active_count; + ktime_t active_time; + int ret; + + spin_lock_irqsave(&ws->lock, flags); + + total_time = ws->total_time; + max_time = ws->max_time; + active_count = ws->active_count; + if (ws->active) { + active_time = ktime_sub(ktime_get(), ws->last_time); + total_time = ktime_add(total_time, active_time); + if (active_time.tv64 > max_time.tv64) + max_time = active_time; + } else { + active_time = ktime_set(0, 0); + } + + ret = seq_printf(m, "%-12s\t%lu\t\t%lu\t\t%lu\t\t" + "%lld\t\t%lld\t\t%lld\t\t%lld\n", + ws->name, active_count, ws->event_count, ws->hit_count, + ktime_to_ms(active_time), ktime_to_ms(total_time), + ktime_to_ms(max_time), ktime_to_ms(ws->last_time)); + + spin_unlock_irqrestore(&ws->lock, flags); + return ret; } + +/** + * wakeup_sources_stats_show - Print wakeup sources statistics information. + * @m: seq_file to print the statistics into. + */ +static int wakeup_sources_stats_show(struct seq_file *m, void *unused) +{ + struct wakeup_source *ws; + + seq_puts(m, "name\t\tactive_count\tevent_count\thit_count\t" + "active_since\ttotal_time\tmax_time\tlast_change\n"); + + rcu_read_lock(); + list_for_each_entry_rcu(ws, &wakeup_sources, entry) + print_wakeup_source_stats(m, ws); + rcu_read_unlock(); + + return 0; +} + +static int wakeup_sources_stats_open(struct inode *inode, struct file *file) +{ + return single_open(file, wakeup_sources_stats_show, NULL); +} + +static const struct file_operations wakeup_sources_stats_fops = { + .owner = THIS_MODULE, + .open = wakeup_sources_stats_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int __init wakeup_sources_debugfs_init(void) +{ + wakeup_sources_stats_dentry = debugfs_create_file("wakeup_sources", + S_IRUGO, NULL, NULL, &wakeup_sources_stats_fops); + return 0; +} + +postcore_initcall(wakeup_sources_debugfs_init); |