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Diffstat (limited to 'drivers/base/power/wakeup.c')
| -rw-r--r-- | drivers/base/power/wakeup.c | 920 |
1 files changed, 920 insertions, 0 deletions
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c new file mode 100644 index 000000000..77262009f --- /dev/null +++ b/drivers/base/power/wakeup.c @@ -0,0 +1,920 @@ +/* + * drivers/base/power/wakeup.c - System wakeup events framework + * + * Copyright (c) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. + * + * This file is released under the GPLv2. + */ + +#include <linux/device.h> +#include <linux/slab.h> +#include <linux/sched.h> +#include <linux/capability.h> +#include <linux/export.h> +#include <linux/suspend.h> +#include <linux/seq_file.h> +#include <linux/debugfs.h> +#include <trace/events/power.h> + +#include "power.h" + +/* + * If set, the suspend/hibernate code will abort transitions to a sleep state + * if wakeup events are registered during or immediately before the transition. + */ +bool events_check_enabled __read_mostly; + +/* If set and the system is suspending, terminate the suspend. */ +static bool pm_abort_suspend __read_mostly; + +/* + * Combined counters of registered wakeup events and wakeup events in progress. + * They need to be modified together atomically, so it's better to use one + * atomic variable to hold them both. + */ +static atomic_t combined_event_count = ATOMIC_INIT(0); + +#define IN_PROGRESS_BITS (sizeof(int) * 4) +#define MAX_IN_PROGRESS ((1 << IN_PROGRESS_BITS) - 1) + +static void split_counters(unsigned int *cnt, unsigned int *inpr) +{ + unsigned int comb = atomic_read(&combined_event_count); + + *cnt = (comb >> IN_PROGRESS_BITS); + *inpr = comb & MAX_IN_PROGRESS; +} + +/* A preserved old value of the events counter. */ +static unsigned int saved_count; + +static DEFINE_SPINLOCK(events_lock); + +static void pm_wakeup_timer_fn(unsigned long data); + +static LIST_HEAD(wakeup_sources); + +static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue); + +/** + * wakeup_source_prepare - Prepare a new wakeup source for initialization. + * @ws: Wakeup source to prepare. + * @name: Pointer to the name of the new wakeup source. + * + * Callers must ensure that the @name string won't be freed when @ws is still in + * use. + */ +void wakeup_source_prepare(struct wakeup_source *ws, const char *name) +{ + if (ws) { + memset(ws, 0, sizeof(*ws)); + ws->name = name; + } +} +EXPORT_SYMBOL_GPL(wakeup_source_prepare); + +/** + * 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 = kmalloc(sizeof(*ws), GFP_KERNEL); + if (!ws) + return NULL; + + wakeup_source_prepare(ws, name ? kstrdup(name, GFP_KERNEL) : NULL); + return ws; +} +EXPORT_SYMBOL_GPL(wakeup_source_create); + +/** + * wakeup_source_drop - Prepare a struct wakeup_source object for destruction. + * @ws: Wakeup source to prepare for destruction. + * + * Callers must ensure that __pm_stay_awake() or __pm_wakeup_event() will never + * be run in parallel with this function for the same wakeup source object. + */ +void wakeup_source_drop(struct wakeup_source *ws) +{ + if (!ws) + return; + + del_timer_sync(&ws->timer); + __pm_relax(ws); +} +EXPORT_SYMBOL_GPL(wakeup_source_drop); + +/** + * wakeup_source_destroy - Destroy a struct wakeup_source object. + * @ws: Wakeup source to destroy. + * + * Use only for wakeup source objects created with wakeup_source_create(). + */ +void wakeup_source_destroy(struct wakeup_source *ws) +{ + if (!ws) + return; + + wakeup_source_drop(ws); + 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) +{ + unsigned long flags; + + if (WARN_ON(!ws)) + return; + + spin_lock_init(&ws->lock); + setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws); + ws->active = false; + ws->last_time = ktime_get(); + + spin_lock_irqsave(&events_lock, flags); + list_add_rcu(&ws->entry, &wakeup_sources); + spin_unlock_irqrestore(&events_lock, flags); +} +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) +{ + unsigned long flags; + + if (WARN_ON(!ws)) + return; + + spin_lock_irqsave(&events_lock, flags); + list_del_rcu(&ws->entry); + spin_unlock_irqrestore(&events_lock, flags); + 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) +{ + if (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_set_wakeup_capable - Set/reset device wakeup capability flag. + * @dev: Device to handle. + * @capable: Whether or not @dev is capable of waking up the system from sleep. + * + * If @capable is set, set the @dev's power.can_wakeup flag and add its + * wakeup-related attributes to sysfs. Otherwise, unset the @dev's + * power.can_wakeup flag and remove its wakeup-related attributes from sysfs. + * + * This function may sleep and it can't be called from any context where + * sleeping is not allowed. + */ +void device_set_wakeup_capable(struct device *dev, bool capable) +{ + if (!!dev->power.can_wakeup == !!capable) + return; + + if (device_is_registered(dev) && !list_empty(&dev->power.entry)) { + if (capable) { + if (wakeup_sysfs_add(dev)) + return; + } else { + wakeup_sysfs_remove(dev); + } + } + dev->power.can_wakeup = capable; +} +EXPORT_SYMBOL_GPL(device_set_wakeup_capable); + +/** + * 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. Also, devices that don't generate their + * own wakeup requests but merely forward requests from one bus to another + * (like PCI bridges) should have wakeup enabled by default. + */ +int device_init_wakeup(struct device *dev, bool enable) +{ + int ret = 0; + + if (!dev) + return -EINVAL; + + if (enable) { + device_set_wakeup_capable(dev, true); + ret = device_wakeup_enable(dev); + } else { + if (dev->power.can_wakeup) + device_wakeup_disable(dev); + + 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 + * period in which the system should not be suspended. The moment this period + * will end depends on how the wakeup event is going to be processed after being + * detected and all of the possible cases can be divided into two distinct + * groups. + * + * First, a wakeup event may be detected by the same functional unit that will + * carry out the entire processing of it and possibly will pass it to user space + * for further processing. In that case the functional unit that has detected + * the event may later "close" the "no suspend" period associated with it + * directly as soon as it has been dealt with. The pair of pm_stay_awake() and + * pm_relax(), balanced with each other, is supposed to be used in such + * situations. + * + * Second, a wakeup event may be detected by one functional unit and processed + * by another one. In that case the unit that has detected it cannot really + * "close" the "no suspend" period associated with it, unless it knows in + * advance what's going to happen to the event during processing. This + * 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) +{ + unsigned int cec; + + /* + * active wakeup source should bring the system + * out of PM_SUSPEND_FREEZE state + */ + freeze_wake(); + + ws->active = true; + ws->active_count++; + ws->last_time = ktime_get(); + if (ws->autosleep_enabled) + ws->start_prevent_time = ws->last_time; + + /* Increment the counter of events in progress. */ + cec = atomic_inc_return(&combined_event_count); + + trace_wakeup_source_activate(ws->name, cec); +} + +/** + * wakeup_source_report_event - Report wakeup event using the given source. + * @ws: Wakeup source to report the event for. + */ +static void wakeup_source_report_event(struct wakeup_source *ws) +{ + ws->event_count++; + /* This is racy, but the counter is approximate anyway. */ + if (events_check_enabled) + ws->wakeup_count++; + + if (!ws->active) + wakeup_source_activate(ws); +} + +/** + * __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); + + wakeup_source_report_event(ws); + del_timer(&ws->timer); + ws->timer_expires = 0; + + 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 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). + */ +void pm_stay_awake(struct device *dev) +{ + unsigned long flags; + + if (!dev) + return; + + 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); + +#ifdef CONFIG_PM_AUTOSLEEP +static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now) +{ + ktime_t delta = ktime_sub(now, ws->start_prevent_time); + ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta); +} +#else +static inline void update_prevent_sleep_time(struct wakeup_source *ws, + ktime_t now) {} +#endif + +/** + * wakup_source_deactivate - Mark given wakeup source as inactive. + * @ws: Wakeup source to handle. + * + * 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) +{ + unsigned int cnt, inpr, cec; + 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; + + ws->last_time = now; + del_timer(&ws->timer); + ws->timer_expires = 0; + + if (ws->autosleep_enabled) + update_prevent_sleep_time(ws, now); + + /* + * Increment the counter of registered wakeup events and decrement the + * couter of wakeup events in progress simultaneously. + */ + cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count); + trace_wakeup_source_deactivate(ws->name, cec); + + split_counters(&cnt, &inpr); + if (!inpr && waitqueue_active(&wakeup_count_wait_queue)) + wake_up(&wakeup_count_wait_queue); +} + +/** + * __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(). + * + * It is safe to call it from interrupt context. + */ +void __pm_relax(struct wakeup_source *ws) +{ + unsigned long 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. + * + * Call wakeup_source_deactivate() for the wakeup source whose address is stored + * in @data if it is currently active and its timer has not been canceled and + * the expiration time of the timer is not in future. + */ +static void pm_wakeup_timer_fn(unsigned long data) +{ + struct wakeup_source *ws = (struct wakeup_source *)data; + unsigned long flags; + + spin_lock_irqsave(&ws->lock, flags); + + if (ws->active && ws->timer_expires + && time_after_eq(jiffies, ws->timer_expires)) { + wakeup_source_deactivate(ws); + ws->expire_count++; + } + + spin_unlock_irqrestore(&ws->lock, flags); +} + +/** + * __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; + + if (!ws) + return; + + spin_lock_irqsave(&ws->lock, flags); + + wakeup_source_report_event(ws); + + if (!msec) { + wakeup_source_deactivate(ws); + goto unlock; + } + + expires = jiffies + msecs_to_jiffies(msec); + if (!expires) + expires = 1; + + if (!ws->timer_expires || 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). + * + * Call __pm_wakeup_event() for the @dev's wakeup source object. + */ +void pm_wakeup_event(struct device *dev, unsigned int msec) +{ + unsigned long flags; + + if (!dev) + return; + + 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); + +void pm_print_active_wakeup_sources(void) +{ + struct wakeup_source *ws; + int active = 0; + struct wakeup_source *last_activity_ws = NULL; + + rcu_read_lock(); + list_for_each_entry_rcu(ws, &wakeup_sources, entry) { + if (ws->active) { + pr_info("active wakeup source: %s\n", ws->name); + active = 1; + } else if (!active && + (!last_activity_ws || + ktime_to_ns(ws->last_time) > + ktime_to_ns(last_activity_ws->last_time))) { + last_activity_ws = ws; + } + } + + if (!active && last_activity_ws) + pr_info("last active wakeup source: %s\n", + last_activity_ws->name); + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources); + +/** + * pm_wakeup_pending - Check if power transition in progress should be aborted. + * + * Compare the current number of registered wakeup events with its preserved + * value from the past and return true if new wakeup events have been registered + * since the old value was stored. Also return true if the current number of + * wakeup events being processed is different from zero. + */ +bool pm_wakeup_pending(void) +{ + unsigned long flags; + bool ret = false; + + spin_lock_irqsave(&events_lock, flags); + if (events_check_enabled) { + unsigned int cnt, inpr; + + split_counters(&cnt, &inpr); + ret = (cnt != saved_count || inpr > 0); + events_check_enabled = !ret; + } + spin_unlock_irqrestore(&events_lock, flags); + + if (ret) { + pr_info("PM: Wakeup pending, aborting suspend\n"); + pm_print_active_wakeup_sources(); + } + + return ret || pm_abort_suspend; +} + +void pm_system_wakeup(void) +{ + pm_abort_suspend = true; + freeze_wake(); +} +EXPORT_SYMBOL_GPL(pm_system_wakeup); + +void pm_wakeup_clear(void) +{ + pm_abort_suspend = false; +} + +/** + * pm_get_wakeup_count - Read the number of registered wakeup events. + * @count: Address to store the value at. + * @block: Whether or not to block. + * + * Store the number of registered wakeup events at the address in @count. If + * @block is set, block until the current number of wakeup events being + * processed is zero. + * + * Return 'false' if the current number of wakeup events being processed is + * nonzero. Otherwise return 'true'. + */ +bool pm_get_wakeup_count(unsigned int *count, bool block) +{ + unsigned int cnt, inpr; + + if (block) { + DEFINE_WAIT(wait); + + for (;;) { + prepare_to_wait(&wakeup_count_wait_queue, &wait, + TASK_INTERRUPTIBLE); + split_counters(&cnt, &inpr); + if (inpr == 0 || signal_pending(current)) + break; + + schedule(); + } + finish_wait(&wakeup_count_wait_queue, &wait); + } + + split_counters(&cnt, &inpr); + *count = cnt; + return !inpr; +} + +/** + * pm_save_wakeup_count - Save the current number of registered wakeup events. + * @count: Value to compare with the current number of registered wakeup events. + * + * If @count is equal to the current number of registered wakeup events and the + * current number of wakeup events being processed is zero, store @count as the + * old number of registered wakeup events for pm_check_wakeup_events(), enable + * wakeup events detection and return 'true'. Otherwise disable wakeup events + * detection and return 'false'. + */ +bool pm_save_wakeup_count(unsigned int count) +{ + unsigned int cnt, inpr; + unsigned long flags; + + events_check_enabled = false; + spin_lock_irqsave(&events_lock, flags); + split_counters(&cnt, &inpr); + if (cnt == count && inpr == 0) { + saved_count = count; + events_check_enabled = true; + } + spin_unlock_irqrestore(&events_lock, flags); + return events_check_enabled; +} + +#ifdef CONFIG_PM_AUTOSLEEP +/** + * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources. + * @enabled: Whether to set or to clear the autosleep_enabled flags. + */ +void pm_wakep_autosleep_enabled(bool set) +{ + struct wakeup_source *ws; + ktime_t now = ktime_get(); + + rcu_read_lock(); + list_for_each_entry_rcu(ws, &wakeup_sources, entry) { + spin_lock_irq(&ws->lock); + if (ws->autosleep_enabled != set) { + ws->autosleep_enabled = set; + if (ws->active) { + if (set) + ws->start_prevent_time = now; + else + update_prevent_sleep_time(ws, now); + } + } + spin_unlock_irq(&ws->lock); + } + rcu_read_unlock(); +} +#endif /* CONFIG_PM_AUTOSLEEP */ + +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; + ktime_t prevent_sleep_time; + + spin_lock_irqsave(&ws->lock, flags); + + total_time = ws->total_time; + max_time = ws->max_time; + prevent_sleep_time = ws->prevent_sleep_time; + active_count = ws->active_count; + if (ws->active) { + ktime_t now = ktime_get(); + + active_time = ktime_sub(now, ws->last_time); + total_time = ktime_add(total_time, active_time); + if (active_time.tv64 > max_time.tv64) + max_time = active_time; + + if (ws->autosleep_enabled) + prevent_sleep_time = ktime_add(prevent_sleep_time, + ktime_sub(now, ws->start_prevent_time)); + } else { + active_time = ktime_set(0, 0); + } + + seq_printf(m, "%-12s\t%lu\t\t%lu\t\t%lu\t\t%lu\t\t%lld\t\t%lld\t\t%lld\t\t%lld\t\t%lld\n", + ws->name, active_count, ws->event_count, + ws->wakeup_count, ws->expire_count, + ktime_to_ms(active_time), ktime_to_ms(total_time), + ktime_to_ms(max_time), ktime_to_ms(ws->last_time), + ktime_to_ms(prevent_sleep_time)); + + spin_unlock_irqrestore(&ws->lock, flags); + + return 0; +} + +/** + * 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\twakeup_count\t" + "expire_count\tactive_since\ttotal_time\tmax_time\t" + "last_change\tprevent_suspend_time\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); |