diff options
Diffstat (limited to 'drivers/base/power/wakeup.c')
| -rw-r--r-- | drivers/base/power/wakeup.c | 448 |
1 files changed, 277 insertions, 171 deletions
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c index 144e6d8fafc8..1e1a0e7eeac5 100644 --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -1,10 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 /* * 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. */ +#define pr_fmt(fmt) "PM: " fmt #include <linux/device.h> #include <linux/slab.h> @@ -19,6 +19,9 @@ #include "power.h" +#define list_for_each_entry_rcu_locked(pos, head, member) \ + list_for_each_entry_rcu(pos, head, member, \ + srcu_read_lock_held(&wakeup_srcu)) /* * If set, the suspend/hibernate code will abort transitions to a sleep state * if wakeup events are registered during or immediately before the transition. @@ -26,7 +29,8 @@ bool events_check_enabled __read_mostly; /* First wakeup IRQ seen by the kernel in the last cycle. */ -unsigned int pm_wakeup_irq __read_mostly; +static unsigned int wakeup_irq[2] __read_mostly; +static DEFINE_RAW_SPINLOCK(wakeup_irq_lock); /* If greater than 0 and the system is suspending, terminate the suspend. */ static atomic_t pm_abort_suspend __read_mostly; @@ -52,9 +56,9 @@ static void split_counters(unsigned int *cnt, unsigned int *inpr) /* A preserved old value of the events counter. */ static unsigned int saved_count; -static DEFINE_SPINLOCK(events_lock); +static DEFINE_RAW_SPINLOCK(events_lock); -static void pm_wakeup_timer_fn(unsigned long data); +static void pm_wakeup_timer_fn(struct timer_list *t); static LIST_HEAD(wakeup_sources); @@ -67,56 +71,41 @@ static struct wakeup_source deleted_ws = { .lock = __SPIN_LOCK_UNLOCKED(deleted_ws.lock), }; -/** - * 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); +static DEFINE_IDA(wakeup_ida); /** * 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) +static struct wakeup_source *wakeup_source_create(const char *name) { struct wakeup_source *ws; + const char *ws_name; + int id; - ws = kmalloc(sizeof(*ws), GFP_KERNEL); + ws = kzalloc(sizeof(*ws), GFP_KERNEL); if (!ws) - return NULL; + goto err_ws; - wakeup_source_prepare(ws, name ? kstrdup_const(name, GFP_KERNEL) : NULL); - return ws; -} -EXPORT_SYMBOL_GPL(wakeup_source_create); + ws_name = kstrdup_const(name, GFP_KERNEL); + if (!ws_name) + goto err_name; + ws->name = ws_name; -/** - * 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; + id = ida_alloc(&wakeup_ida, GFP_KERNEL); + if (id < 0) + goto err_id; + ws->id = id; - del_timer_sync(&ws->timer); - __pm_relax(ws); + return ws; + +err_id: + kfree_const(ws->name); +err_name: + kfree(ws); +err_ws: + return NULL; } -EXPORT_SYMBOL_GPL(wakeup_source_drop); /* * Record wakeup_source statistics being deleted into a dummy wakeup_source. @@ -146,29 +135,34 @@ static void wakeup_source_record(struct wakeup_source *ws) spin_unlock_irqrestore(&deleted_ws.lock, flags); } +static void wakeup_source_free(struct wakeup_source *ws) +{ + ida_free(&wakeup_ida, ws->id); + kfree_const(ws->name); + kfree(ws); +} + /** * 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) +static void wakeup_source_destroy(struct wakeup_source *ws) { if (!ws) return; - wakeup_source_drop(ws); + __pm_relax(ws); wakeup_source_record(ws); - kfree_const(ws->name); - kfree(ws); + wakeup_source_free(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) +static void wakeup_source_add(struct wakeup_source *ws) { unsigned long flags; @@ -176,46 +170,59 @@ void wakeup_source_add(struct wakeup_source *ws) return; spin_lock_init(&ws->lock); - setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws); + timer_setup(&ws->timer, pm_wakeup_timer_fn, 0); ws->active = false; - ws->last_time = ktime_get(); - spin_lock_irqsave(&events_lock, flags); + raw_spin_lock_irqsave(&events_lock, flags); list_add_rcu(&ws->entry, &wakeup_sources); - spin_unlock_irqrestore(&events_lock, flags); + raw_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) +static void wakeup_source_remove(struct wakeup_source *ws) { unsigned long flags; if (WARN_ON(!ws)) return; - spin_lock_irqsave(&events_lock, flags); + /* + * After shutting down the timer, wakeup_source_activate() will warn if + * the given wakeup source is passed to it. + */ + timer_shutdown_sync(&ws->timer); + + raw_spin_lock_irqsave(&events_lock, flags); list_del_rcu(&ws->entry); - spin_unlock_irqrestore(&events_lock, flags); + raw_spin_unlock_irqrestore(&events_lock, flags); synchronize_srcu(&wakeup_srcu); } -EXPORT_SYMBOL_GPL(wakeup_source_remove); /** * wakeup_source_register - Create wakeup source and add it to the list. + * @dev: Device this wakeup source is associated with (or NULL if virtual). * @name: Name of the wakeup source to register. */ -struct wakeup_source *wakeup_source_register(const char *name) +struct wakeup_source *wakeup_source_register(struct device *dev, + const char *name) { struct wakeup_source *ws; + int ret; ws = wakeup_source_create(name); - if (ws) + if (ws) { + if (!dev || device_is_registered(dev)) { + ret = wakeup_source_sysfs_add(dev, ws); + if (ret) { + wakeup_source_free(ws); + return NULL; + } + } wakeup_source_add(ws); - + } return ws; } EXPORT_SYMBOL_GPL(wakeup_source_register); @@ -228,12 +235,69 @@ void wakeup_source_unregister(struct wakeup_source *ws) { if (ws) { wakeup_source_remove(ws); + if (ws->dev) + wakeup_source_sysfs_remove(ws); + wakeup_source_destroy(ws); } } EXPORT_SYMBOL_GPL(wakeup_source_unregister); /** + * wakeup_sources_read_lock - Lock wakeup source list for read. + * + * Returns an index of srcu lock for struct wakeup_srcu. + * This index must be passed to the matching wakeup_sources_read_unlock(). + */ +int wakeup_sources_read_lock(void) +{ + return srcu_read_lock(&wakeup_srcu); +} +EXPORT_SYMBOL_GPL(wakeup_sources_read_lock); + +/** + * wakeup_sources_read_unlock - Unlock wakeup source list. + * @idx: return value from corresponding wakeup_sources_read_lock() + */ +void wakeup_sources_read_unlock(int idx) +{ + srcu_read_unlock(&wakeup_srcu, idx); +} +EXPORT_SYMBOL_GPL(wakeup_sources_read_unlock); + +/** + * wakeup_sources_walk_start - Begin a walk on wakeup source list + * + * Returns first object of the list of wakeup sources. + * + * Note that to be safe, wakeup sources list needs to be locked by calling + * wakeup_source_read_lock() for this. + */ +struct wakeup_source *wakeup_sources_walk_start(void) +{ + struct list_head *ws_head = &wakeup_sources; + + return list_entry_rcu(ws_head->next, struct wakeup_source, entry); +} +EXPORT_SYMBOL_GPL(wakeup_sources_walk_start); + +/** + * wakeup_sources_walk_next - Get next wakeup source from the list + * @ws: Previous wakeup source object + * + * Note that to be safe, wakeup sources list needs to be locked by calling + * wakeup_source_read_lock() for this. + */ +struct wakeup_source *wakeup_sources_walk_next(struct wakeup_source *ws) +{ + struct list_head *ws_head = &wakeup_sources; + + return list_next_or_null_rcu(ws_head, &ws->entry, + struct wakeup_source, entry); +} +EXPORT_SYMBOL_GPL(wakeup_sources_walk_next); + +/** * device_wakeup_attach - Attach a wakeup source object to a device object. * @dev: Device to handle. * @ws: Wakeup source object to attach to @dev. @@ -268,7 +332,10 @@ int device_wakeup_enable(struct device *dev) if (!dev || !dev->power.can_wakeup) return -EINVAL; - ws = wakeup_source_register(dev_name(dev)); + if (pm_sleep_transition_in_progress()) + dev_dbg(dev, "Suspicious %s() during system transition!\n", __func__); + + ws = wakeup_source_register(dev, dev_name(dev)); if (!ws) return -ENOMEM; @@ -291,22 +358,19 @@ EXPORT_SYMBOL_GPL(device_wakeup_enable); * * Call under the device's power.lock lock. */ -int device_wakeup_attach_irq(struct device *dev, +void device_wakeup_attach_irq(struct device *dev, struct wake_irq *wakeirq) { struct wakeup_source *ws; ws = dev->power.wakeup; - if (!ws) { - dev_err(dev, "forgot to call call device_init_wakeup?\n"); - return -EINVAL; - } + if (!ws) + return; if (ws->wakeirq) - return -EEXIST; + dev_err(dev, "Leftover wakeup IRQ found, overriding\n"); ws->wakeirq = wakeirq; - return 0; } /** @@ -327,9 +391,9 @@ void device_wakeup_detach_irq(struct device *dev) } /** - * device_wakeup_arm_wake_irqs(void) + * device_wakeup_arm_wake_irqs - * - * Itereates over the list of device wakeirqs to arm them. + * Iterates over the list of device wakeirqs to arm them. */ void device_wakeup_arm_wake_irqs(void) { @@ -337,15 +401,15 @@ void device_wakeup_arm_wake_irqs(void) int srcuidx; srcuidx = srcu_read_lock(&wakeup_srcu); - list_for_each_entry_rcu(ws, &wakeup_sources, entry) + list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry) dev_pm_arm_wake_irq(ws->wakeirq); srcu_read_unlock(&wakeup_srcu, srcuidx); } /** - * device_wakeup_disarm_wake_irqs(void) + * device_wakeup_disarm_wake_irqs - * - * Itereates over the list of device wakeirqs to disarm them. + * Iterates over the list of device wakeirqs to disarm them. */ void device_wakeup_disarm_wake_irqs(void) { @@ -353,7 +417,7 @@ void device_wakeup_disarm_wake_irqs(void) int srcuidx; srcuidx = srcu_read_lock(&wakeup_srcu); - list_for_each_entry_rcu(ws, &wakeup_sources, entry) + list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry) dev_pm_disarm_wake_irq(ws->wakeirq); srcu_read_unlock(&wakeup_srcu, srcuidx); } @@ -382,16 +446,15 @@ static struct wakeup_source *device_wakeup_detach(struct device *dev) * Detach the @dev's wakeup source object from it, unregister this wakeup source * object and destroy it. */ -int device_wakeup_disable(struct device *dev) +void device_wakeup_disable(struct device *dev) { struct wakeup_source *ws; if (!dev || !dev->power.can_wakeup) - return -EINVAL; + return; ws = device_wakeup_detach(dev); wakeup_source_unregister(ws); - return 0; } EXPORT_SYMBOL_GPL(device_wakeup_disable); @@ -412,75 +475,46 @@ void device_set_wakeup_capable(struct device *dev, bool capable) if (!!dev->power.can_wakeup == !!capable) return; + dev->power.can_wakeup = capable; if (device_is_registered(dev) && !list_empty(&dev->power.entry)) { if (capable) { - if (wakeup_sysfs_add(dev)) - return; + int ret = wakeup_sysfs_add(dev); + + if (ret) + dev_info(dev, "Wakeup sysfs attributes not added\n"); } 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. + * @enable: enable/disable flag */ int device_set_wakeup_enable(struct device *dev, bool enable) { - if (!dev || !dev->power.can_wakeup) - return -EINVAL; + if (enable) + return device_wakeup_enable(dev); - return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev); + device_wakeup_disable(dev); + return 0; } EXPORT_SYMBOL_GPL(device_set_wakeup_enable); /** - * wakeup_source_not_registered - validate the given wakeup source. + * wakeup_source_not_usable - validate the given wakeup source. * @ws: Wakeup source to be validated. */ -static bool wakeup_source_not_registered(struct wakeup_source *ws) +static bool wakeup_source_not_usable(struct wakeup_source *ws) { /* - * Use timer struct to check if the given source is initialized - * by wakeup_source_add. + * Use the timer struct to check if the given wakeup source has been + * initialized by wakeup_source_add() and it is not going away. */ - return ws->timer.function != pm_wakeup_timer_fn || - ws->timer.data != (unsigned long)ws; + return ws->timer.function != pm_wakeup_timer_fn; } /* @@ -512,19 +546,18 @@ static bool wakeup_source_not_registered(struct wakeup_source *ws) */ /** - * wakup_source_activate - Mark given wakeup source as active. + * wakeup_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 + * core of the event by incrementing the counter of the wakeup events being * processed. */ static void wakeup_source_activate(struct wakeup_source *ws) { unsigned int cec; - if (WARN_ONCE(wakeup_source_not_registered(ws), - "unregistered wakeup source\n")) + if (WARN_ONCE(wakeup_source_not_usable(ws), "unusable wakeup source\n")) return; ws->active = true; @@ -574,7 +607,7 @@ void __pm_stay_awake(struct wakeup_source *ws) spin_lock_irqsave(&ws->lock, flags); wakeup_source_report_event(ws, false); - del_timer(&ws->timer); + timer_delete(&ws->timer); ws->timer_expires = 0; spin_unlock_irqrestore(&ws->lock, flags); @@ -617,7 +650,7 @@ static inline void update_prevent_sleep_time(struct wakeup_source *ws, #endif /** - * wakup_source_deactivate - Mark given wakeup source as inactive. + * wakeup_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 @@ -654,7 +687,7 @@ static void wakeup_source_deactivate(struct wakeup_source *ws) ws->max_time = duration; ws->last_time = now; - del_timer(&ws->timer); + timer_delete(&ws->timer); ws->timer_expires = 0; if (ws->autosleep_enabled) @@ -662,7 +695,7 @@ static void wakeup_source_deactivate(struct wakeup_source *ws) /* * Increment the counter of registered wakeup events and decrement the - * couter of wakeup events in progress simultaneously. + * counter of wakeup events in progress simultaneously. */ cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count); trace_wakeup_source_deactivate(ws->name, cec); @@ -716,15 +749,15 @@ 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. + * @t: timer list * * 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) +static void pm_wakeup_timer_fn(struct timer_list *t) { - struct wakeup_source *ws = (struct wakeup_source *)data; + struct wakeup_source *ws = timer_container_of(ws, t, timer); unsigned long flags; spin_lock_irqsave(&ws->lock, flags); @@ -783,7 +816,7 @@ void pm_wakeup_ws_event(struct wakeup_source *ws, unsigned int msec, bool hard) EXPORT_SYMBOL_GPL(pm_wakeup_ws_event); /** - * pm_wakeup_event - Notify the PM core of a wakeup event. + * pm_wakeup_dev_event - Notify the PM core of a wakeup event. * @dev: Device the wakeup event is related to. * @msec: Anticipated event processing time (in milliseconds). * @hard: If set, abort suspends in progress and wake up from suspend-to-idle. @@ -810,9 +843,9 @@ void pm_print_active_wakeup_sources(void) struct wakeup_source *last_activity_ws = NULL; srcuidx = srcu_read_lock(&wakeup_srcu); - list_for_each_entry_rcu(ws, &wakeup_sources, entry) { + list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry) { if (ws->active) { - pr_debug("active wakeup source: %s\n", ws->name); + pm_pr_dbg("active wakeup source: %s\n", ws->name); active = 1; } else if (!active && (!last_activity_ws || @@ -823,7 +856,7 @@ void pm_print_active_wakeup_sources(void) } if (!active && last_activity_ws) - pr_debug("last active wakeup source: %s\n", + pm_pr_dbg("last active wakeup source: %s\n", last_activity_ws->name); srcu_read_unlock(&wakeup_srcu, srcuidx); } @@ -842,7 +875,7 @@ bool pm_wakeup_pending(void) unsigned long flags; bool ret = false; - spin_lock_irqsave(&events_lock, flags); + raw_spin_lock_irqsave(&events_lock, flags); if (events_check_enabled) { unsigned int cnt, inpr; @@ -850,41 +883,70 @@ bool pm_wakeup_pending(void) ret = (cnt != saved_count || inpr > 0); events_check_enabled = !ret; } - spin_unlock_irqrestore(&events_lock, flags); + raw_spin_unlock_irqrestore(&events_lock, flags); if (ret) { - pr_info("PM: Wakeup pending, aborting suspend\n"); + pm_pr_dbg("Wakeup pending, aborting suspend\n"); pm_print_active_wakeup_sources(); } return ret || atomic_read(&pm_abort_suspend) > 0; } +EXPORT_SYMBOL_GPL(pm_wakeup_pending); void pm_system_wakeup(void) { atomic_inc(&pm_abort_suspend); - freeze_wake(); + s2idle_wake(); } EXPORT_SYMBOL_GPL(pm_system_wakeup); void pm_system_cancel_wakeup(void) { - atomic_dec(&pm_abort_suspend); + atomic_dec_if_positive(&pm_abort_suspend); } -void pm_wakeup_clear(bool reset) +void pm_wakeup_clear(unsigned int irq_number) { - pm_wakeup_irq = 0; - if (reset) + raw_spin_lock_irq(&wakeup_irq_lock); + + if (irq_number && wakeup_irq[0] == irq_number) + wakeup_irq[0] = wakeup_irq[1]; + else + wakeup_irq[0] = 0; + + wakeup_irq[1] = 0; + + raw_spin_unlock_irq(&wakeup_irq_lock); + + if (!irq_number) atomic_set(&pm_abort_suspend, 0); } void pm_system_irq_wakeup(unsigned int irq_number) { - if (pm_wakeup_irq == 0) { - pm_wakeup_irq = irq_number; + unsigned long flags; + + raw_spin_lock_irqsave(&wakeup_irq_lock, flags); + + if (wakeup_irq[0] == 0) + wakeup_irq[0] = irq_number; + else if (wakeup_irq[1] == 0) + wakeup_irq[1] = irq_number; + else + irq_number = 0; + + pm_pr_dbg("Triggering wakeup from IRQ %d\n", irq_number); + + raw_spin_unlock_irqrestore(&wakeup_irq_lock, flags); + + if (irq_number) pm_system_wakeup(); - } +} + +unsigned int pm_wakeup_irq(void) +{ + return wakeup_irq[0]; } /** @@ -939,20 +1001,20 @@ bool pm_save_wakeup_count(unsigned int count) unsigned long flags; events_check_enabled = false; - spin_lock_irqsave(&events_lock, flags); + raw_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); + raw_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. + * @set: Whether to set or to clear the autosleep_enabled flags. */ void pm_wakep_autosleep_enabled(bool set) { @@ -961,7 +1023,7 @@ void pm_wakep_autosleep_enabled(bool set) int srcuidx; srcuidx = srcu_read_lock(&wakeup_srcu); - list_for_each_entry_rcu(ws, &wakeup_sources, entry) { + list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry) { spin_lock_irq(&ws->lock); if (ws->autosleep_enabled != set) { ws->autosleep_enabled = set; @@ -978,8 +1040,6 @@ void pm_wakep_autosleep_enabled(bool set) } #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. @@ -1028,32 +1088,78 @@ static int print_wakeup_source_stats(struct seq_file *m, 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) +static void *wakeup_sources_stats_seq_start(struct seq_file *m, + loff_t *pos) { struct wakeup_source *ws; - int srcuidx; + loff_t n = *pos; + int *srcuidx = m->private; - 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"); + if (n == 0) { + 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"); + } - srcuidx = srcu_read_lock(&wakeup_srcu); - list_for_each_entry_rcu(ws, &wakeup_sources, entry) - print_wakeup_source_stats(m, ws); - srcu_read_unlock(&wakeup_srcu, srcuidx); + *srcuidx = srcu_read_lock(&wakeup_srcu); + list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry) { + if (n-- <= 0) + return ws; + } + + return NULL; +} + +static void *wakeup_sources_stats_seq_next(struct seq_file *m, + void *v, loff_t *pos) +{ + struct wakeup_source *ws = v; + struct wakeup_source *next_ws = NULL; - print_wakeup_source_stats(m, &deleted_ws); + ++(*pos); + + list_for_each_entry_continue_rcu(ws, &wakeup_sources, entry) { + next_ws = ws; + break; + } + + if (!next_ws) + print_wakeup_source_stats(m, &deleted_ws); + + return next_ws; +} + +static void wakeup_sources_stats_seq_stop(struct seq_file *m, void *v) +{ + int *srcuidx = m->private; + + srcu_read_unlock(&wakeup_srcu, *srcuidx); +} + +/** + * wakeup_sources_stats_seq_show - Print wakeup sources statistics information. + * @m: seq_file to print the statistics into. + * @v: wakeup_source of each iteration + */ +static int wakeup_sources_stats_seq_show(struct seq_file *m, void *v) +{ + struct wakeup_source *ws = v; + + print_wakeup_source_stats(m, ws); return 0; } +static const struct seq_operations wakeup_sources_stats_seq_ops = { + .start = wakeup_sources_stats_seq_start, + .next = wakeup_sources_stats_seq_next, + .stop = wakeup_sources_stats_seq_stop, + .show = wakeup_sources_stats_seq_show, +}; + static int wakeup_sources_stats_open(struct inode *inode, struct file *file) { - return single_open(file, wakeup_sources_stats_show, NULL); + return seq_open_private(file, &wakeup_sources_stats_seq_ops, sizeof(int)); } static const struct file_operations wakeup_sources_stats_fops = { @@ -1061,13 +1167,13 @@ static const struct file_operations wakeup_sources_stats_fops = { .open = wakeup_sources_stats_open, .read = seq_read, .llseek = seq_lseek, - .release = single_release, + .release = seq_release_private, }; 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); + debugfs_create_file("wakeup_sources", 0444, NULL, NULL, + &wakeup_sources_stats_fops); return 0; } |
