2 * drivers/base/power/runtime.c - Helper functions for device runtime PM
4 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
5 * Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu>
7 * This file is released under the GPLv2.
10 #include <linux/sched.h>
11 #include <linux/export.h>
12 #include <linux/pm_runtime.h>
13 #include <linux/pm_wakeirq.h>
14 #include <trace/events/rpm.h>
17 typedef int (*pm_callback_t)(struct device *);
19 static pm_callback_t __rpm_get_callback(struct device *dev, size_t cb_offset)
22 const struct dev_pm_ops *ops;
25 ops = &dev->pm_domain->ops;
26 else if (dev->type && dev->type->pm)
28 else if (dev->class && dev->class->pm)
30 else if (dev->bus && dev->bus->pm)
36 cb = *(pm_callback_t *)((void *)ops + cb_offset);
40 if (!cb && dev->driver && dev->driver->pm)
41 cb = *(pm_callback_t *)((void *)dev->driver->pm + cb_offset);
46 #define RPM_GET_CALLBACK(dev, callback) \
47 __rpm_get_callback(dev, offsetof(struct dev_pm_ops, callback))
49 static int rpm_resume(struct device *dev, int rpmflags);
50 static int rpm_suspend(struct device *dev, int rpmflags);
53 * update_pm_runtime_accounting - Update the time accounting of power states
54 * @dev: Device to update the accounting for
56 * In order to be able to have time accounting of the various power states
57 * (as used by programs such as PowerTOP to show the effectiveness of runtime
58 * PM), we need to track the time spent in each state.
59 * update_pm_runtime_accounting must be called each time before the
60 * runtime_status field is updated, to account the time in the old state
63 void update_pm_runtime_accounting(struct device *dev)
65 unsigned long now = jiffies;
68 delta = now - dev->power.accounting_timestamp;
70 dev->power.accounting_timestamp = now;
72 if (dev->power.disable_depth > 0)
75 if (dev->power.runtime_status == RPM_SUSPENDED)
76 dev->power.suspended_jiffies += delta;
78 dev->power.active_jiffies += delta;
81 static void __update_runtime_status(struct device *dev, enum rpm_status status)
83 update_pm_runtime_accounting(dev);
84 dev->power.runtime_status = status;
88 * pm_runtime_deactivate_timer - Deactivate given device's suspend timer.
89 * @dev: Device to handle.
91 static void pm_runtime_deactivate_timer(struct device *dev)
93 if (dev->power.timer_expires > 0) {
94 del_timer(&dev->power.suspend_timer);
95 dev->power.timer_expires = 0;
100 * pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests.
101 * @dev: Device to handle.
103 static void pm_runtime_cancel_pending(struct device *dev)
105 pm_runtime_deactivate_timer(dev);
107 * In case there's a request pending, make sure its work function will
108 * return without doing anything.
110 dev->power.request = RPM_REQ_NONE;
114 * pm_runtime_autosuspend_expiration - Get a device's autosuspend-delay expiration time.
115 * @dev: Device to handle.
117 * Compute the autosuspend-delay expiration time based on the device's
118 * power.last_busy time. If the delay has already expired or is disabled
119 * (negative) or the power.use_autosuspend flag isn't set, return 0.
120 * Otherwise return the expiration time in jiffies (adjusted to be nonzero).
122 * This function may be called either with or without dev->power.lock held.
123 * Either way it can be racy, since power.last_busy may be updated at any time.
125 unsigned long pm_runtime_autosuspend_expiration(struct device *dev)
127 int autosuspend_delay;
129 unsigned long last_busy;
130 unsigned long expires = 0;
132 if (!dev->power.use_autosuspend)
135 autosuspend_delay = ACCESS_ONCE(dev->power.autosuspend_delay);
136 if (autosuspend_delay < 0)
139 last_busy = ACCESS_ONCE(dev->power.last_busy);
140 elapsed = jiffies - last_busy;
142 goto out; /* jiffies has wrapped around. */
145 * If the autosuspend_delay is >= 1 second, align the timer by rounding
146 * up to the nearest second.
148 expires = last_busy + msecs_to_jiffies(autosuspend_delay);
149 if (autosuspend_delay >= 1000)
150 expires = round_jiffies(expires);
152 if (elapsed >= expires - last_busy)
153 expires = 0; /* Already expired. */
158 EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration);
160 static int dev_memalloc_noio(struct device *dev, void *data)
162 return dev->power.memalloc_noio;
166 * pm_runtime_set_memalloc_noio - Set a device's memalloc_noio flag.
167 * @dev: Device to handle.
168 * @enable: True for setting the flag and False for clearing the flag.
170 * Set the flag for all devices in the path from the device to the
171 * root device in the device tree if @enable is true, otherwise clear
172 * the flag for devices in the path whose siblings don't set the flag.
174 * The function should only be called by block device, or network
175 * device driver for solving the deadlock problem during runtime
178 * If memory allocation with GFP_KERNEL is called inside runtime
179 * resume/suspend callback of any one of its ancestors(or the
180 * block device itself), the deadlock may be triggered inside the
181 * memory allocation since it might not complete until the block
182 * device becomes active and the involed page I/O finishes. The
183 * situation is pointed out first by Alan Stern. Network device
184 * are involved in iSCSI kind of situation.
186 * The lock of dev_hotplug_mutex is held in the function for handling
187 * hotplug race because pm_runtime_set_memalloc_noio() may be called
190 * The function should be called between device_add() and device_del()
191 * on the affected device(block/network device).
193 void pm_runtime_set_memalloc_noio(struct device *dev, bool enable)
195 static DEFINE_MUTEX(dev_hotplug_mutex);
197 mutex_lock(&dev_hotplug_mutex);
201 /* hold power lock since bitfield is not SMP-safe. */
202 spin_lock_irq(&dev->power.lock);
203 enabled = dev->power.memalloc_noio;
204 dev->power.memalloc_noio = enable;
205 spin_unlock_irq(&dev->power.lock);
208 * not need to enable ancestors any more if the device
211 if (enabled && enable)
217 * clear flag of the parent device only if all the
218 * children don't set the flag because ancestor's
219 * flag was set by any one of the descendants.
221 if (!dev || (!enable &&
222 device_for_each_child(dev, NULL,
226 mutex_unlock(&dev_hotplug_mutex);
228 EXPORT_SYMBOL_GPL(pm_runtime_set_memalloc_noio);
231 * rpm_check_suspend_allowed - Test whether a device may be suspended.
232 * @dev: Device to test.
234 static int rpm_check_suspend_allowed(struct device *dev)
238 if (dev->power.runtime_error)
240 else if (dev->power.disable_depth > 0)
242 else if (atomic_read(&dev->power.usage_count) > 0)
244 else if (!pm_children_suspended(dev))
247 /* Pending resume requests take precedence over suspends. */
248 else if ((dev->power.deferred_resume
249 && dev->power.runtime_status == RPM_SUSPENDING)
250 || (dev->power.request_pending
251 && dev->power.request == RPM_REQ_RESUME))
253 else if (__dev_pm_qos_read_value(dev) < 0)
255 else if (dev->power.runtime_status == RPM_SUSPENDED)
262 * __rpm_callback - Run a given runtime PM callback for a given device.
263 * @cb: Runtime PM callback to run.
264 * @dev: Device to run the callback for.
266 static int __rpm_callback(int (*cb)(struct device *), struct device *dev)
267 __releases(&dev->power.lock) __acquires(&dev->power.lock)
271 if (dev->power.irq_safe)
272 spin_unlock(&dev->power.lock);
274 spin_unlock_irq(&dev->power.lock);
278 if (dev->power.irq_safe)
279 spin_lock(&dev->power.lock);
281 spin_lock_irq(&dev->power.lock);
287 * rpm_idle - Notify device bus type if the device can be suspended.
288 * @dev: Device to notify the bus type about.
289 * @rpmflags: Flag bits.
291 * Check if the device's runtime PM status allows it to be suspended. If
292 * another idle notification has been started earlier, return immediately. If
293 * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise
294 * run the ->runtime_idle() callback directly. If the ->runtime_idle callback
295 * doesn't exist or if it returns 0, call rpm_suspend with the RPM_AUTO flag.
297 * This function must be called under dev->power.lock with interrupts disabled.
299 static int rpm_idle(struct device *dev, int rpmflags)
301 int (*callback)(struct device *);
304 trace_rpm_idle_rcuidle(dev, rpmflags);
305 retval = rpm_check_suspend_allowed(dev);
307 ; /* Conditions are wrong. */
309 /* Idle notifications are allowed only in the RPM_ACTIVE state. */
310 else if (dev->power.runtime_status != RPM_ACTIVE)
314 * Any pending request other than an idle notification takes
315 * precedence over us, except that the timer may be running.
317 else if (dev->power.request_pending &&
318 dev->power.request > RPM_REQ_IDLE)
321 /* Act as though RPM_NOWAIT is always set. */
322 else if (dev->power.idle_notification)
323 retval = -EINPROGRESS;
327 /* Pending requests need to be canceled. */
328 dev->power.request = RPM_REQ_NONE;
330 if (dev->power.no_callbacks)
333 /* Carry out an asynchronous or a synchronous idle notification. */
334 if (rpmflags & RPM_ASYNC) {
335 dev->power.request = RPM_REQ_IDLE;
336 if (!dev->power.request_pending) {
337 dev->power.request_pending = true;
338 queue_work(pm_wq, &dev->power.work);
340 trace_rpm_return_int_rcuidle(dev, _THIS_IP_, 0);
344 dev->power.idle_notification = true;
346 callback = RPM_GET_CALLBACK(dev, runtime_idle);
349 retval = __rpm_callback(callback, dev);
351 dev->power.idle_notification = false;
352 wake_up_all(&dev->power.wait_queue);
355 trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
356 return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO);
360 * rpm_callback - Run a given runtime PM callback for a given device.
361 * @cb: Runtime PM callback to run.
362 * @dev: Device to run the callback for.
364 static int rpm_callback(int (*cb)(struct device *), struct device *dev)
371 if (dev->power.memalloc_noio) {
372 unsigned int noio_flag;
375 * Deadlock might be caused if memory allocation with
376 * GFP_KERNEL happens inside runtime_suspend and
377 * runtime_resume callbacks of one block device's
378 * ancestor or the block device itself. Network
379 * device might be thought as part of iSCSI block
380 * device, so network device and its ancestor should
381 * be marked as memalloc_noio too.
383 noio_flag = memalloc_noio_save();
384 retval = __rpm_callback(cb, dev);
385 memalloc_noio_restore(noio_flag);
387 retval = __rpm_callback(cb, dev);
390 dev->power.runtime_error = retval;
391 return retval != -EACCES ? retval : -EIO;
395 * rpm_suspend - Carry out runtime suspend of given device.
396 * @dev: Device to suspend.
397 * @rpmflags: Flag bits.
399 * Check if the device's runtime PM status allows it to be suspended.
400 * Cancel a pending idle notification, autosuspend or suspend. If
401 * another suspend has been started earlier, either return immediately
402 * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC
403 * flags. If the RPM_ASYNC flag is set then queue a suspend request;
404 * otherwise run the ->runtime_suspend() callback directly. When
405 * ->runtime_suspend succeeded, if a deferred resume was requested while
406 * the callback was running then carry it out, otherwise send an idle
407 * notification for its parent (if the suspend succeeded and both
408 * ignore_children of parent->power and irq_safe of dev->power are not set).
409 * If ->runtime_suspend failed with -EAGAIN or -EBUSY, and if the RPM_AUTO
410 * flag is set and the next autosuspend-delay expiration time is in the
411 * future, schedule another autosuspend attempt.
413 * This function must be called under dev->power.lock with interrupts disabled.
415 static int rpm_suspend(struct device *dev, int rpmflags)
416 __releases(&dev->power.lock) __acquires(&dev->power.lock)
418 int (*callback)(struct device *);
419 struct device *parent = NULL;
422 trace_rpm_suspend_rcuidle(dev, rpmflags);
425 retval = rpm_check_suspend_allowed(dev);
428 ; /* Conditions are wrong. */
430 /* Synchronous suspends are not allowed in the RPM_RESUMING state. */
431 else if (dev->power.runtime_status == RPM_RESUMING &&
432 !(rpmflags & RPM_ASYNC))
437 /* If the autosuspend_delay time hasn't expired yet, reschedule. */
438 if ((rpmflags & RPM_AUTO)
439 && dev->power.runtime_status != RPM_SUSPENDING) {
440 unsigned long expires = pm_runtime_autosuspend_expiration(dev);
443 /* Pending requests need to be canceled. */
444 dev->power.request = RPM_REQ_NONE;
447 * Optimization: If the timer is already running and is
448 * set to expire at or before the autosuspend delay,
449 * avoid the overhead of resetting it. Just let it
450 * expire; pm_suspend_timer_fn() will take care of the
453 if (!(dev->power.timer_expires && time_before_eq(
454 dev->power.timer_expires, expires))) {
455 dev->power.timer_expires = expires;
456 mod_timer(&dev->power.suspend_timer, expires);
458 dev->power.timer_autosuspends = 1;
463 /* Other scheduled or pending requests need to be canceled. */
464 pm_runtime_cancel_pending(dev);
466 if (dev->power.runtime_status == RPM_SUSPENDING) {
469 if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
470 retval = -EINPROGRESS;
474 if (dev->power.irq_safe) {
475 spin_unlock(&dev->power.lock);
479 spin_lock(&dev->power.lock);
483 /* Wait for the other suspend running in parallel with us. */
485 prepare_to_wait(&dev->power.wait_queue, &wait,
486 TASK_UNINTERRUPTIBLE);
487 if (dev->power.runtime_status != RPM_SUSPENDING)
490 spin_unlock_irq(&dev->power.lock);
494 spin_lock_irq(&dev->power.lock);
496 finish_wait(&dev->power.wait_queue, &wait);
500 if (dev->power.no_callbacks)
501 goto no_callback; /* Assume success. */
503 /* Carry out an asynchronous or a synchronous suspend. */
504 if (rpmflags & RPM_ASYNC) {
505 dev->power.request = (rpmflags & RPM_AUTO) ?
506 RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND;
507 if (!dev->power.request_pending) {
508 dev->power.request_pending = true;
509 queue_work(pm_wq, &dev->power.work);
514 __update_runtime_status(dev, RPM_SUSPENDING);
516 callback = RPM_GET_CALLBACK(dev, runtime_suspend);
518 dev_pm_enable_wake_irq_check(dev, true);
519 retval = rpm_callback(callback, dev);
524 __update_runtime_status(dev, RPM_SUSPENDED);
525 pm_runtime_deactivate_timer(dev);
528 parent = dev->parent;
529 atomic_add_unless(&parent->power.child_count, -1, 0);
531 wake_up_all(&dev->power.wait_queue);
533 if (dev->power.deferred_resume) {
534 dev->power.deferred_resume = false;
540 /* Maybe the parent is now able to suspend. */
541 if (parent && !parent->power.ignore_children && !dev->power.irq_safe) {
542 spin_unlock(&dev->power.lock);
544 spin_lock(&parent->power.lock);
545 rpm_idle(parent, RPM_ASYNC);
546 spin_unlock(&parent->power.lock);
548 spin_lock(&dev->power.lock);
552 trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
557 dev_pm_disable_wake_irq_check(dev);
558 __update_runtime_status(dev, RPM_ACTIVE);
559 dev->power.deferred_resume = false;
560 wake_up_all(&dev->power.wait_queue);
562 if (retval == -EAGAIN || retval == -EBUSY) {
563 dev->power.runtime_error = 0;
566 * If the callback routine failed an autosuspend, and
567 * if the last_busy time has been updated so that there
568 * is a new autosuspend expiration time, automatically
569 * reschedule another autosuspend.
571 if ((rpmflags & RPM_AUTO) &&
572 pm_runtime_autosuspend_expiration(dev) != 0)
575 pm_runtime_cancel_pending(dev);
581 * rpm_resume - Carry out runtime resume of given device.
582 * @dev: Device to resume.
583 * @rpmflags: Flag bits.
585 * Check if the device's runtime PM status allows it to be resumed. Cancel
586 * any scheduled or pending requests. If another resume has been started
587 * earlier, either return immediately or wait for it to finish, depending on the
588 * RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in
589 * parallel with this function, either tell the other process to resume after
590 * suspending (deferred_resume) or wait for it to finish. If the RPM_ASYNC
591 * flag is set then queue a resume request; otherwise run the
592 * ->runtime_resume() callback directly. Queue an idle notification for the
593 * device if the resume succeeded.
595 * This function must be called under dev->power.lock with interrupts disabled.
597 static int rpm_resume(struct device *dev, int rpmflags)
598 __releases(&dev->power.lock) __acquires(&dev->power.lock)
600 int (*callback)(struct device *);
601 struct device *parent = NULL;
604 trace_rpm_resume_rcuidle(dev, rpmflags);
607 if (dev->power.runtime_error)
609 else if (dev->power.disable_depth == 1 && dev->power.is_suspended
610 && dev->power.runtime_status == RPM_ACTIVE)
612 else if (dev->power.disable_depth > 0)
618 * Other scheduled or pending requests need to be canceled. Small
619 * optimization: If an autosuspend timer is running, leave it running
620 * rather than cancelling it now only to restart it again in the near
623 dev->power.request = RPM_REQ_NONE;
624 if (!dev->power.timer_autosuspends)
625 pm_runtime_deactivate_timer(dev);
627 if (dev->power.runtime_status == RPM_ACTIVE) {
632 if (dev->power.runtime_status == RPM_RESUMING
633 || dev->power.runtime_status == RPM_SUSPENDING) {
636 if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
637 if (dev->power.runtime_status == RPM_SUSPENDING)
638 dev->power.deferred_resume = true;
640 retval = -EINPROGRESS;
644 if (dev->power.irq_safe) {
645 spin_unlock(&dev->power.lock);
649 spin_lock(&dev->power.lock);
653 /* Wait for the operation carried out in parallel with us. */
655 prepare_to_wait(&dev->power.wait_queue, &wait,
656 TASK_UNINTERRUPTIBLE);
657 if (dev->power.runtime_status != RPM_RESUMING
658 && dev->power.runtime_status != RPM_SUSPENDING)
661 spin_unlock_irq(&dev->power.lock);
665 spin_lock_irq(&dev->power.lock);
667 finish_wait(&dev->power.wait_queue, &wait);
672 * See if we can skip waking up the parent. This is safe only if
673 * power.no_callbacks is set, because otherwise we don't know whether
674 * the resume will actually succeed.
676 if (dev->power.no_callbacks && !parent && dev->parent) {
677 spin_lock_nested(&dev->parent->power.lock, SINGLE_DEPTH_NESTING);
678 if (dev->parent->power.disable_depth > 0
679 || dev->parent->power.ignore_children
680 || dev->parent->power.runtime_status == RPM_ACTIVE) {
681 atomic_inc(&dev->parent->power.child_count);
682 spin_unlock(&dev->parent->power.lock);
684 goto no_callback; /* Assume success. */
686 spin_unlock(&dev->parent->power.lock);
689 /* Carry out an asynchronous or a synchronous resume. */
690 if (rpmflags & RPM_ASYNC) {
691 dev->power.request = RPM_REQ_RESUME;
692 if (!dev->power.request_pending) {
693 dev->power.request_pending = true;
694 queue_work(pm_wq, &dev->power.work);
700 if (!parent && dev->parent) {
702 * Increment the parent's usage counter and resume it if
703 * necessary. Not needed if dev is irq-safe; then the
704 * parent is permanently resumed.
706 parent = dev->parent;
707 if (dev->power.irq_safe)
709 spin_unlock(&dev->power.lock);
711 pm_runtime_get_noresume(parent);
713 spin_lock(&parent->power.lock);
715 * We can resume if the parent's runtime PM is disabled or it
716 * is set to ignore children.
718 if (!parent->power.disable_depth
719 && !parent->power.ignore_children) {
720 rpm_resume(parent, 0);
721 if (parent->power.runtime_status != RPM_ACTIVE)
724 spin_unlock(&parent->power.lock);
726 spin_lock(&dev->power.lock);
733 if (dev->power.no_callbacks)
734 goto no_callback; /* Assume success. */
736 __update_runtime_status(dev, RPM_RESUMING);
738 callback = RPM_GET_CALLBACK(dev, runtime_resume);
740 dev_pm_disable_wake_irq_check(dev);
741 retval = rpm_callback(callback, dev);
743 __update_runtime_status(dev, RPM_SUSPENDED);
744 pm_runtime_cancel_pending(dev);
745 dev_pm_enable_wake_irq_check(dev, false);
748 __update_runtime_status(dev, RPM_ACTIVE);
749 pm_runtime_mark_last_busy(dev);
751 atomic_inc(&parent->power.child_count);
753 wake_up_all(&dev->power.wait_queue);
756 rpm_idle(dev, RPM_ASYNC);
759 if (parent && !dev->power.irq_safe) {
760 spin_unlock_irq(&dev->power.lock);
762 pm_runtime_put(parent);
764 spin_lock_irq(&dev->power.lock);
767 trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
773 * pm_runtime_work - Universal runtime PM work function.
774 * @work: Work structure used for scheduling the execution of this function.
776 * Use @work to get the device object the work is to be done for, determine what
777 * is to be done and execute the appropriate runtime PM function.
779 static void pm_runtime_work(struct work_struct *work)
781 struct device *dev = container_of(work, struct device, power.work);
782 enum rpm_request req;
784 spin_lock_irq(&dev->power.lock);
786 if (!dev->power.request_pending)
789 req = dev->power.request;
790 dev->power.request = RPM_REQ_NONE;
791 dev->power.request_pending = false;
797 rpm_idle(dev, RPM_NOWAIT);
799 case RPM_REQ_SUSPEND:
800 rpm_suspend(dev, RPM_NOWAIT);
802 case RPM_REQ_AUTOSUSPEND:
803 rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO);
806 rpm_resume(dev, RPM_NOWAIT);
811 spin_unlock_irq(&dev->power.lock);
815 * pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
816 * @data: Device pointer passed by pm_schedule_suspend().
818 * Check if the time is right and queue a suspend request.
820 static void pm_suspend_timer_fn(unsigned long data)
822 struct device *dev = (struct device *)data;
824 unsigned long expires;
826 spin_lock_irqsave(&dev->power.lock, flags);
828 expires = dev->power.timer_expires;
829 /* If 'expire' is after 'jiffies' we've been called too early. */
830 if (expires > 0 && !time_after(expires, jiffies)) {
831 dev->power.timer_expires = 0;
832 rpm_suspend(dev, dev->power.timer_autosuspends ?
833 (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC);
836 spin_unlock_irqrestore(&dev->power.lock, flags);
840 * pm_schedule_suspend - Set up a timer to submit a suspend request in future.
841 * @dev: Device to suspend.
842 * @delay: Time to wait before submitting a suspend request, in milliseconds.
844 int pm_schedule_suspend(struct device *dev, unsigned int delay)
849 spin_lock_irqsave(&dev->power.lock, flags);
852 retval = rpm_suspend(dev, RPM_ASYNC);
856 retval = rpm_check_suspend_allowed(dev);
860 /* Other scheduled or pending requests need to be canceled. */
861 pm_runtime_cancel_pending(dev);
863 dev->power.timer_expires = jiffies + msecs_to_jiffies(delay);
864 dev->power.timer_expires += !dev->power.timer_expires;
865 dev->power.timer_autosuspends = 0;
866 mod_timer(&dev->power.suspend_timer, dev->power.timer_expires);
869 spin_unlock_irqrestore(&dev->power.lock, flags);
873 EXPORT_SYMBOL_GPL(pm_schedule_suspend);
876 * __pm_runtime_idle - Entry point for runtime idle operations.
877 * @dev: Device to send idle notification for.
878 * @rpmflags: Flag bits.
880 * If the RPM_GET_PUT flag is set, decrement the device's usage count and
881 * return immediately if it is larger than zero. Then carry out an idle
882 * notification, either synchronous or asynchronous.
884 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
885 * or if pm_runtime_irq_safe() has been called.
887 int __pm_runtime_idle(struct device *dev, int rpmflags)
892 if (rpmflags & RPM_GET_PUT) {
893 if (!atomic_dec_and_test(&dev->power.usage_count))
897 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
899 spin_lock_irqsave(&dev->power.lock, flags);
900 retval = rpm_idle(dev, rpmflags);
901 spin_unlock_irqrestore(&dev->power.lock, flags);
905 EXPORT_SYMBOL_GPL(__pm_runtime_idle);
908 * __pm_runtime_suspend - Entry point for runtime put/suspend operations.
909 * @dev: Device to suspend.
910 * @rpmflags: Flag bits.
912 * If the RPM_GET_PUT flag is set, decrement the device's usage count and
913 * return immediately if it is larger than zero. Then carry out a suspend,
914 * either synchronous or asynchronous.
916 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
917 * or if pm_runtime_irq_safe() has been called.
919 int __pm_runtime_suspend(struct device *dev, int rpmflags)
924 if (rpmflags & RPM_GET_PUT) {
925 if (!atomic_dec_and_test(&dev->power.usage_count))
929 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
931 spin_lock_irqsave(&dev->power.lock, flags);
932 retval = rpm_suspend(dev, rpmflags);
933 spin_unlock_irqrestore(&dev->power.lock, flags);
937 EXPORT_SYMBOL_GPL(__pm_runtime_suspend);
940 * __pm_runtime_resume - Entry point for runtime resume operations.
941 * @dev: Device to resume.
942 * @rpmflags: Flag bits.
944 * If the RPM_GET_PUT flag is set, increment the device's usage count. Then
945 * carry out a resume, either synchronous or asynchronous.
947 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
948 * or if pm_runtime_irq_safe() has been called.
950 int __pm_runtime_resume(struct device *dev, int rpmflags)
955 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe &&
956 dev->power.runtime_status != RPM_ACTIVE);
958 if (rpmflags & RPM_GET_PUT)
959 atomic_inc(&dev->power.usage_count);
961 spin_lock_irqsave(&dev->power.lock, flags);
962 retval = rpm_resume(dev, rpmflags);
963 spin_unlock_irqrestore(&dev->power.lock, flags);
967 EXPORT_SYMBOL_GPL(__pm_runtime_resume);
970 * pm_runtime_get_if_in_use - Conditionally bump up the device's usage counter.
971 * @dev: Device to handle.
973 * Return -EINVAL if runtime PM is disabled for the device.
975 * If that's not the case and if the device's runtime PM status is RPM_ACTIVE
976 * and the runtime PM usage counter is nonzero, increment the counter and
977 * return 1. Otherwise return 0 without changing the counter.
979 int pm_runtime_get_if_in_use(struct device *dev)
984 spin_lock_irqsave(&dev->power.lock, flags);
985 retval = dev->power.disable_depth > 0 ? -EINVAL :
986 dev->power.runtime_status == RPM_ACTIVE
987 && atomic_inc_not_zero(&dev->power.usage_count);
988 spin_unlock_irqrestore(&dev->power.lock, flags);
991 EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use);
994 * __pm_runtime_set_status - Set runtime PM status of a device.
995 * @dev: Device to handle.
996 * @status: New runtime PM status of the device.
998 * If runtime PM of the device is disabled or its power.runtime_error field is
999 * different from zero, the status may be changed either to RPM_ACTIVE, or to
1000 * RPM_SUSPENDED, as long as that reflects the actual state of the device.
1001 * However, if the device has a parent and the parent is not active, and the
1002 * parent's power.ignore_children flag is unset, the device's status cannot be
1003 * set to RPM_ACTIVE, so -EBUSY is returned in that case.
1005 * If successful, __pm_runtime_set_status() clears the power.runtime_error field
1006 * and the device parent's counter of unsuspended children is modified to
1007 * reflect the new status. If the new status is RPM_SUSPENDED, an idle
1008 * notification request for the parent is submitted.
1010 int __pm_runtime_set_status(struct device *dev, unsigned int status)
1012 struct device *parent = dev->parent;
1013 unsigned long flags;
1014 bool notify_parent = false;
1017 if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
1020 spin_lock_irqsave(&dev->power.lock, flags);
1022 if (!dev->power.runtime_error && !dev->power.disable_depth) {
1027 if (dev->power.runtime_status == status)
1030 if (status == RPM_SUSPENDED) {
1031 /* It always is possible to set the status to 'suspended'. */
1033 atomic_add_unless(&parent->power.child_count, -1, 0);
1034 notify_parent = !parent->power.ignore_children;
1040 spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);
1043 * It is invalid to put an active child under a parent that is
1044 * not active, has runtime PM enabled and the
1045 * 'power.ignore_children' flag unset.
1047 if (!parent->power.disable_depth
1048 && !parent->power.ignore_children
1049 && parent->power.runtime_status != RPM_ACTIVE) {
1050 dev_err(dev, "runtime PM trying to activate child device %s but parent (%s) is not active\n",
1054 } else if (dev->power.runtime_status == RPM_SUSPENDED) {
1055 atomic_inc(&parent->power.child_count);
1058 spin_unlock(&parent->power.lock);
1065 __update_runtime_status(dev, status);
1066 dev->power.runtime_error = 0;
1068 spin_unlock_irqrestore(&dev->power.lock, flags);
1071 pm_request_idle(parent);
1075 EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
1078 * __pm_runtime_barrier - Cancel pending requests and wait for completions.
1079 * @dev: Device to handle.
1081 * Flush all pending requests for the device from pm_wq and wait for all
1082 * runtime PM operations involving the device in progress to complete.
1084 * Should be called under dev->power.lock with interrupts disabled.
1086 static void __pm_runtime_barrier(struct device *dev)
1088 pm_runtime_deactivate_timer(dev);
1090 if (dev->power.request_pending) {
1091 dev->power.request = RPM_REQ_NONE;
1092 spin_unlock_irq(&dev->power.lock);
1094 cancel_work_sync(&dev->power.work);
1096 spin_lock_irq(&dev->power.lock);
1097 dev->power.request_pending = false;
1100 if (dev->power.runtime_status == RPM_SUSPENDING
1101 || dev->power.runtime_status == RPM_RESUMING
1102 || dev->power.idle_notification) {
1105 /* Suspend, wake-up or idle notification in progress. */
1107 prepare_to_wait(&dev->power.wait_queue, &wait,
1108 TASK_UNINTERRUPTIBLE);
1109 if (dev->power.runtime_status != RPM_SUSPENDING
1110 && dev->power.runtime_status != RPM_RESUMING
1111 && !dev->power.idle_notification)
1113 spin_unlock_irq(&dev->power.lock);
1117 spin_lock_irq(&dev->power.lock);
1119 finish_wait(&dev->power.wait_queue, &wait);
1124 * pm_runtime_barrier - Flush pending requests and wait for completions.
1125 * @dev: Device to handle.
1127 * Prevent the device from being suspended by incrementing its usage counter and
1128 * if there's a pending resume request for the device, wake the device up.
1129 * Next, make sure that all pending requests for the device have been flushed
1130 * from pm_wq and wait for all runtime PM operations involving the device in
1131 * progress to complete.
1134 * 1, if there was a resume request pending and the device had to be woken up,
1137 int pm_runtime_barrier(struct device *dev)
1141 pm_runtime_get_noresume(dev);
1142 spin_lock_irq(&dev->power.lock);
1144 if (dev->power.request_pending
1145 && dev->power.request == RPM_REQ_RESUME) {
1150 __pm_runtime_barrier(dev);
1152 spin_unlock_irq(&dev->power.lock);
1153 pm_runtime_put_noidle(dev);
1157 EXPORT_SYMBOL_GPL(pm_runtime_barrier);
1160 * __pm_runtime_disable - Disable runtime PM of a device.
1161 * @dev: Device to handle.
1162 * @check_resume: If set, check if there's a resume request for the device.
1164 * Increment power.disable_depth for the device and if it was zero previously,
1165 * cancel all pending runtime PM requests for the device and wait for all
1166 * operations in progress to complete. The device can be either active or
1167 * suspended after its runtime PM has been disabled.
1169 * If @check_resume is set and there's a resume request pending when
1170 * __pm_runtime_disable() is called and power.disable_depth is zero, the
1171 * function will wake up the device before disabling its runtime PM.
1173 void __pm_runtime_disable(struct device *dev, bool check_resume)
1175 spin_lock_irq(&dev->power.lock);
1177 if (dev->power.disable_depth > 0) {
1178 dev->power.disable_depth++;
1183 * Wake up the device if there's a resume request pending, because that
1184 * means there probably is some I/O to process and disabling runtime PM
1185 * shouldn't prevent the device from processing the I/O.
1187 if (check_resume && dev->power.request_pending
1188 && dev->power.request == RPM_REQ_RESUME) {
1190 * Prevent suspends and idle notifications from being carried
1191 * out after we have woken up the device.
1193 pm_runtime_get_noresume(dev);
1197 pm_runtime_put_noidle(dev);
1200 if (!dev->power.disable_depth++)
1201 __pm_runtime_barrier(dev);
1204 spin_unlock_irq(&dev->power.lock);
1206 EXPORT_SYMBOL_GPL(__pm_runtime_disable);
1209 * pm_runtime_enable - Enable runtime PM of a device.
1210 * @dev: Device to handle.
1212 void pm_runtime_enable(struct device *dev)
1214 unsigned long flags;
1216 spin_lock_irqsave(&dev->power.lock, flags);
1218 if (dev->power.disable_depth > 0)
1219 dev->power.disable_depth--;
1221 dev_warn(dev, "Unbalanced %s!\n", __func__);
1223 spin_unlock_irqrestore(&dev->power.lock, flags);
1225 EXPORT_SYMBOL_GPL(pm_runtime_enable);
1228 * pm_runtime_forbid - Block runtime PM of a device.
1229 * @dev: Device to handle.
1231 * Increase the device's usage count and clear its power.runtime_auto flag,
1232 * so that it cannot be suspended at run time until pm_runtime_allow() is called
1235 void pm_runtime_forbid(struct device *dev)
1237 spin_lock_irq(&dev->power.lock);
1238 if (!dev->power.runtime_auto)
1241 dev->power.runtime_auto = false;
1242 atomic_inc(&dev->power.usage_count);
1246 spin_unlock_irq(&dev->power.lock);
1248 EXPORT_SYMBOL_GPL(pm_runtime_forbid);
1251 * pm_runtime_allow - Unblock runtime PM of a device.
1252 * @dev: Device to handle.
1254 * Decrease the device's usage count and set its power.runtime_auto flag.
1256 void pm_runtime_allow(struct device *dev)
1258 spin_lock_irq(&dev->power.lock);
1259 if (dev->power.runtime_auto)
1262 dev->power.runtime_auto = true;
1263 if (atomic_dec_and_test(&dev->power.usage_count))
1264 rpm_idle(dev, RPM_AUTO | RPM_ASYNC);
1267 spin_unlock_irq(&dev->power.lock);
1269 EXPORT_SYMBOL_GPL(pm_runtime_allow);
1272 * pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device.
1273 * @dev: Device to handle.
1275 * Set the power.no_callbacks flag, which tells the PM core that this
1276 * device is power-managed through its parent and has no runtime PM
1277 * callbacks of its own. The runtime sysfs attributes will be removed.
1279 void pm_runtime_no_callbacks(struct device *dev)
1281 spin_lock_irq(&dev->power.lock);
1282 dev->power.no_callbacks = 1;
1283 spin_unlock_irq(&dev->power.lock);
1284 if (device_is_registered(dev))
1285 rpm_sysfs_remove(dev);
1287 EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks);
1290 * pm_runtime_irq_safe - Leave interrupts disabled during callbacks.
1291 * @dev: Device to handle
1293 * Set the power.irq_safe flag, which tells the PM core that the
1294 * ->runtime_suspend() and ->runtime_resume() callbacks for this device should
1295 * always be invoked with the spinlock held and interrupts disabled. It also
1296 * causes the parent's usage counter to be permanently incremented, preventing
1297 * the parent from runtime suspending -- otherwise an irq-safe child might have
1298 * to wait for a non-irq-safe parent.
1300 void pm_runtime_irq_safe(struct device *dev)
1303 pm_runtime_get_sync(dev->parent);
1304 spin_lock_irq(&dev->power.lock);
1305 dev->power.irq_safe = 1;
1306 spin_unlock_irq(&dev->power.lock);
1308 EXPORT_SYMBOL_GPL(pm_runtime_irq_safe);
1311 * update_autosuspend - Handle a change to a device's autosuspend settings.
1312 * @dev: Device to handle.
1313 * @old_delay: The former autosuspend_delay value.
1314 * @old_use: The former use_autosuspend value.
1316 * Prevent runtime suspend if the new delay is negative and use_autosuspend is
1317 * set; otherwise allow it. Send an idle notification if suspends are allowed.
1319 * This function must be called under dev->power.lock with interrupts disabled.
1321 static void update_autosuspend(struct device *dev, int old_delay, int old_use)
1323 int delay = dev->power.autosuspend_delay;
1325 /* Should runtime suspend be prevented now? */
1326 if (dev->power.use_autosuspend && delay < 0) {
1328 /* If it used to be allowed then prevent it. */
1329 if (!old_use || old_delay >= 0) {
1330 atomic_inc(&dev->power.usage_count);
1335 /* Runtime suspend should be allowed now. */
1338 /* If it used to be prevented then allow it. */
1339 if (old_use && old_delay < 0)
1340 atomic_dec(&dev->power.usage_count);
1342 /* Maybe we can autosuspend now. */
1343 rpm_idle(dev, RPM_AUTO);
1348 * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value.
1349 * @dev: Device to handle.
1350 * @delay: Value of the new delay in milliseconds.
1352 * Set the device's power.autosuspend_delay value. If it changes to negative
1353 * and the power.use_autosuspend flag is set, prevent runtime suspends. If it
1354 * changes the other way, allow runtime suspends.
1356 void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
1358 int old_delay, old_use;
1360 spin_lock_irq(&dev->power.lock);
1361 old_delay = dev->power.autosuspend_delay;
1362 old_use = dev->power.use_autosuspend;
1363 dev->power.autosuspend_delay = delay;
1364 update_autosuspend(dev, old_delay, old_use);
1365 spin_unlock_irq(&dev->power.lock);
1367 EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);
1370 * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag.
1371 * @dev: Device to handle.
1372 * @use: New value for use_autosuspend.
1374 * Set the device's power.use_autosuspend flag, and allow or prevent runtime
1375 * suspends as needed.
1377 void __pm_runtime_use_autosuspend(struct device *dev, bool use)
1379 int old_delay, old_use;
1381 spin_lock_irq(&dev->power.lock);
1382 old_delay = dev->power.autosuspend_delay;
1383 old_use = dev->power.use_autosuspend;
1384 dev->power.use_autosuspend = use;
1385 update_autosuspend(dev, old_delay, old_use);
1386 spin_unlock_irq(&dev->power.lock);
1388 EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);
1391 * pm_runtime_init - Initialize runtime PM fields in given device object.
1392 * @dev: Device object to initialize.
1394 void pm_runtime_init(struct device *dev)
1396 dev->power.runtime_status = RPM_SUSPENDED;
1397 dev->power.idle_notification = false;
1399 dev->power.disable_depth = 1;
1400 atomic_set(&dev->power.usage_count, 0);
1402 dev->power.runtime_error = 0;
1404 atomic_set(&dev->power.child_count, 0);
1405 pm_suspend_ignore_children(dev, false);
1406 dev->power.runtime_auto = true;
1408 dev->power.request_pending = false;
1409 dev->power.request = RPM_REQ_NONE;
1410 dev->power.deferred_resume = false;
1411 dev->power.accounting_timestamp = jiffies;
1412 INIT_WORK(&dev->power.work, pm_runtime_work);
1414 dev->power.timer_expires = 0;
1415 setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn,
1416 (unsigned long)dev);
1418 init_waitqueue_head(&dev->power.wait_queue);
1422 * pm_runtime_reinit - Re-initialize runtime PM fields in given device object.
1423 * @dev: Device object to re-initialize.
1425 void pm_runtime_reinit(struct device *dev)
1427 if (!pm_runtime_enabled(dev)) {
1428 if (dev->power.runtime_status == RPM_ACTIVE)
1429 pm_runtime_set_suspended(dev);
1430 if (dev->power.irq_safe) {
1431 spin_lock_irq(&dev->power.lock);
1432 dev->power.irq_safe = 0;
1433 spin_unlock_irq(&dev->power.lock);
1435 pm_runtime_put(dev->parent);
1441 * pm_runtime_remove - Prepare for removing a device from device hierarchy.
1442 * @dev: Device object being removed from device hierarchy.
1444 void pm_runtime_remove(struct device *dev)
1446 __pm_runtime_disable(dev, false);
1447 pm_runtime_reinit(dev);
1451 * pm_runtime_force_suspend - Force a device into suspend state if needed.
1452 * @dev: Device to suspend.
1454 * Disable runtime PM so we safely can check the device's runtime PM status and
1455 * if it is active, invoke it's .runtime_suspend callback to bring it into
1456 * suspend state. Keep runtime PM disabled to preserve the state unless we
1459 * Typically this function may be invoked from a system suspend callback to make
1460 * sure the device is put into low power state.
1462 int pm_runtime_force_suspend(struct device *dev)
1464 int (*callback)(struct device *);
1467 pm_runtime_disable(dev);
1468 if (pm_runtime_status_suspended(dev))
1471 callback = RPM_GET_CALLBACK(dev, runtime_suspend);
1478 ret = callback(dev);
1482 pm_runtime_set_suspended(dev);
1485 pm_runtime_enable(dev);
1488 EXPORT_SYMBOL_GPL(pm_runtime_force_suspend);
1491 * pm_runtime_force_resume - Force a device into resume state.
1492 * @dev: Device to resume.
1494 * Prior invoking this function we expect the user to have brought the device
1495 * into low power state by a call to pm_runtime_force_suspend(). Here we reverse
1496 * those actions and brings the device into full power. We update the runtime PM
1497 * status and re-enables runtime PM.
1499 * Typically this function may be invoked from a system resume callback to make
1500 * sure the device is put into full power state.
1502 int pm_runtime_force_resume(struct device *dev)
1504 int (*callback)(struct device *);
1507 callback = RPM_GET_CALLBACK(dev, runtime_resume);
1514 if (!pm_runtime_status_suspended(dev))
1517 ret = pm_runtime_set_active(dev);
1521 ret = callback(dev);
1523 pm_runtime_set_suspended(dev);
1527 pm_runtime_mark_last_busy(dev);
1529 pm_runtime_enable(dev);
1532 EXPORT_SYMBOL_GPL(pm_runtime_force_resume);