1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * drivers/base/power/runtime.c - Helper functions for device runtime PM |
4 | * |
5 | * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. |
6 | * Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu> |
7 | */ |
8 | #include <linux/sched/mm.h> |
9 | #include <linux/ktime.h> |
10 | #include <linux/hrtimer.h> |
11 | #include <linux/export.h> |
12 | #include <linux/pm_runtime.h> |
13 | #include <linux/pm_wakeirq.h> |
14 | #include <linux/rculist.h> |
15 | #include <trace/events/rpm.h> |
16 | |
17 | #include "../base.h" |
18 | #include "power.h" |
19 | |
20 | typedef int (*pm_callback_t)(struct device *); |
21 | |
22 | static pm_callback_t __rpm_get_callback(struct device *dev, size_t cb_offset) |
23 | { |
24 | pm_callback_t cb; |
25 | const struct dev_pm_ops *ops; |
26 | |
27 | if (dev->pm_domain) |
28 | ops = &dev->pm_domain->ops; |
29 | else if (dev->type && dev->type->pm) |
30 | ops = dev->type->pm; |
31 | else if (dev->class && dev->class->pm) |
32 | ops = dev->class->pm; |
33 | else if (dev->bus && dev->bus->pm) |
34 | ops = dev->bus->pm; |
35 | else |
36 | ops = NULL; |
37 | |
38 | if (ops) |
39 | cb = *(pm_callback_t *)((void *)ops + cb_offset); |
40 | else |
41 | cb = NULL; |
42 | |
43 | if (!cb && dev->driver && dev->driver->pm) |
44 | cb = *(pm_callback_t *)((void *)dev->driver->pm + cb_offset); |
45 | |
46 | return cb; |
47 | } |
48 | |
49 | #define RPM_GET_CALLBACK(dev, callback) \ |
50 | __rpm_get_callback(dev, offsetof(struct dev_pm_ops, callback)) |
51 | |
52 | static int rpm_resume(struct device *dev, int rpmflags); |
53 | static int rpm_suspend(struct device *dev, int rpmflags); |
54 | |
55 | /** |
56 | * update_pm_runtime_accounting - Update the time accounting of power states |
57 | * @dev: Device to update the accounting for |
58 | * |
59 | * In order to be able to have time accounting of the various power states |
60 | * (as used by programs such as PowerTOP to show the effectiveness of runtime |
61 | * PM), we need to track the time spent in each state. |
62 | * update_pm_runtime_accounting must be called each time before the |
63 | * runtime_status field is updated, to account the time in the old state |
64 | * correctly. |
65 | */ |
66 | static void update_pm_runtime_accounting(struct device *dev) |
67 | { |
68 | u64 now, last, delta; |
69 | |
70 | if (dev->power.disable_depth > 0) |
71 | return; |
72 | |
73 | last = dev->power.accounting_timestamp; |
74 | |
75 | now = ktime_get_mono_fast_ns(); |
76 | dev->power.accounting_timestamp = now; |
77 | |
78 | /* |
79 | * Because ktime_get_mono_fast_ns() is not monotonic during |
80 | * timekeeping updates, ensure that 'now' is after the last saved |
81 | * timesptamp. |
82 | */ |
83 | if (now < last) |
84 | return; |
85 | |
86 | delta = now - last; |
87 | |
88 | if (dev->power.runtime_status == RPM_SUSPENDED) |
89 | dev->power.suspended_time += delta; |
90 | else |
91 | dev->power.active_time += delta; |
92 | } |
93 | |
94 | static void __update_runtime_status(struct device *dev, enum rpm_status status) |
95 | { |
96 | update_pm_runtime_accounting(dev); |
97 | trace_rpm_status(dev, status); |
98 | dev->power.runtime_status = status; |
99 | } |
100 | |
101 | static u64 rpm_get_accounted_time(struct device *dev, bool suspended) |
102 | { |
103 | u64 time; |
104 | unsigned long flags; |
105 | |
106 | spin_lock_irqsave(&dev->power.lock, flags); |
107 | |
108 | update_pm_runtime_accounting(dev); |
109 | time = suspended ? dev->power.suspended_time : dev->power.active_time; |
110 | |
111 | spin_unlock_irqrestore(lock: &dev->power.lock, flags); |
112 | |
113 | return time; |
114 | } |
115 | |
116 | u64 pm_runtime_active_time(struct device *dev) |
117 | { |
118 | return rpm_get_accounted_time(dev, suspended: false); |
119 | } |
120 | |
121 | u64 pm_runtime_suspended_time(struct device *dev) |
122 | { |
123 | return rpm_get_accounted_time(dev, suspended: true); |
124 | } |
125 | EXPORT_SYMBOL_GPL(pm_runtime_suspended_time); |
126 | |
127 | /** |
128 | * pm_runtime_deactivate_timer - Deactivate given device's suspend timer. |
129 | * @dev: Device to handle. |
130 | */ |
131 | static void pm_runtime_deactivate_timer(struct device *dev) |
132 | { |
133 | if (dev->power.timer_expires > 0) { |
134 | hrtimer_try_to_cancel(timer: &dev->power.suspend_timer); |
135 | dev->power.timer_expires = 0; |
136 | } |
137 | } |
138 | |
139 | /** |
140 | * pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests. |
141 | * @dev: Device to handle. |
142 | */ |
143 | static void pm_runtime_cancel_pending(struct device *dev) |
144 | { |
145 | pm_runtime_deactivate_timer(dev); |
146 | /* |
147 | * In case there's a request pending, make sure its work function will |
148 | * return without doing anything. |
149 | */ |
150 | dev->power.request = RPM_REQ_NONE; |
151 | } |
152 | |
153 | /* |
154 | * pm_runtime_autosuspend_expiration - Get a device's autosuspend-delay expiration time. |
155 | * @dev: Device to handle. |
156 | * |
157 | * Compute the autosuspend-delay expiration time based on the device's |
158 | * power.last_busy time. If the delay has already expired or is disabled |
159 | * (negative) or the power.use_autosuspend flag isn't set, return 0. |
160 | * Otherwise return the expiration time in nanoseconds (adjusted to be nonzero). |
161 | * |
162 | * This function may be called either with or without dev->power.lock held. |
163 | * Either way it can be racy, since power.last_busy may be updated at any time. |
164 | */ |
165 | u64 pm_runtime_autosuspend_expiration(struct device *dev) |
166 | { |
167 | int autosuspend_delay; |
168 | u64 expires; |
169 | |
170 | if (!dev->power.use_autosuspend) |
171 | return 0; |
172 | |
173 | autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay); |
174 | if (autosuspend_delay < 0) |
175 | return 0; |
176 | |
177 | expires = READ_ONCE(dev->power.last_busy); |
178 | expires += (u64)autosuspend_delay * NSEC_PER_MSEC; |
179 | if (expires > ktime_get_mono_fast_ns()) |
180 | return expires; /* Expires in the future */ |
181 | |
182 | return 0; |
183 | } |
184 | EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration); |
185 | |
186 | static int dev_memalloc_noio(struct device *dev, void *data) |
187 | { |
188 | return dev->power.memalloc_noio; |
189 | } |
190 | |
191 | /* |
192 | * pm_runtime_set_memalloc_noio - Set a device's memalloc_noio flag. |
193 | * @dev: Device to handle. |
194 | * @enable: True for setting the flag and False for clearing the flag. |
195 | * |
196 | * Set the flag for all devices in the path from the device to the |
197 | * root device in the device tree if @enable is true, otherwise clear |
198 | * the flag for devices in the path whose siblings don't set the flag. |
199 | * |
200 | * The function should only be called by block device, or network |
201 | * device driver for solving the deadlock problem during runtime |
202 | * resume/suspend: |
203 | * |
204 | * If memory allocation with GFP_KERNEL is called inside runtime |
205 | * resume/suspend callback of any one of its ancestors(or the |
206 | * block device itself), the deadlock may be triggered inside the |
207 | * memory allocation since it might not complete until the block |
208 | * device becomes active and the involed page I/O finishes. The |
209 | * situation is pointed out first by Alan Stern. Network device |
210 | * are involved in iSCSI kind of situation. |
211 | * |
212 | * The lock of dev_hotplug_mutex is held in the function for handling |
213 | * hotplug race because pm_runtime_set_memalloc_noio() may be called |
214 | * in async probe(). |
215 | * |
216 | * The function should be called between device_add() and device_del() |
217 | * on the affected device(block/network device). |
218 | */ |
219 | void pm_runtime_set_memalloc_noio(struct device *dev, bool enable) |
220 | { |
221 | static DEFINE_MUTEX(dev_hotplug_mutex); |
222 | |
223 | mutex_lock(&dev_hotplug_mutex); |
224 | for (;;) { |
225 | bool enabled; |
226 | |
227 | /* hold power lock since bitfield is not SMP-safe. */ |
228 | spin_lock_irq(lock: &dev->power.lock); |
229 | enabled = dev->power.memalloc_noio; |
230 | dev->power.memalloc_noio = enable; |
231 | spin_unlock_irq(lock: &dev->power.lock); |
232 | |
233 | /* |
234 | * not need to enable ancestors any more if the device |
235 | * has been enabled. |
236 | */ |
237 | if (enabled && enable) |
238 | break; |
239 | |
240 | dev = dev->parent; |
241 | |
242 | /* |
243 | * clear flag of the parent device only if all the |
244 | * children don't set the flag because ancestor's |
245 | * flag was set by any one of the descendants. |
246 | */ |
247 | if (!dev || (!enable && |
248 | device_for_each_child(dev, NULL, fn: dev_memalloc_noio))) |
249 | break; |
250 | } |
251 | mutex_unlock(lock: &dev_hotplug_mutex); |
252 | } |
253 | EXPORT_SYMBOL_GPL(pm_runtime_set_memalloc_noio); |
254 | |
255 | /** |
256 | * rpm_check_suspend_allowed - Test whether a device may be suspended. |
257 | * @dev: Device to test. |
258 | */ |
259 | static int rpm_check_suspend_allowed(struct device *dev) |
260 | { |
261 | int retval = 0; |
262 | |
263 | if (dev->power.runtime_error) |
264 | retval = -EINVAL; |
265 | else if (dev->power.disable_depth > 0) |
266 | retval = -EACCES; |
267 | else if (atomic_read(v: &dev->power.usage_count)) |
268 | retval = -EAGAIN; |
269 | else if (!dev->power.ignore_children && atomic_read(v: &dev->power.child_count)) |
270 | retval = -EBUSY; |
271 | |
272 | /* Pending resume requests take precedence over suspends. */ |
273 | else if ((dev->power.deferred_resume && |
274 | dev->power.runtime_status == RPM_SUSPENDING) || |
275 | (dev->power.request_pending && dev->power.request == RPM_REQ_RESUME)) |
276 | retval = -EAGAIN; |
277 | else if (__dev_pm_qos_resume_latency(dev) == 0) |
278 | retval = -EPERM; |
279 | else if (dev->power.runtime_status == RPM_SUSPENDED) |
280 | retval = 1; |
281 | |
282 | return retval; |
283 | } |
284 | |
285 | static int rpm_get_suppliers(struct device *dev) |
286 | { |
287 | struct device_link *link; |
288 | |
289 | list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, |
290 | device_links_read_lock_held()) { |
291 | int retval; |
292 | |
293 | if (!(link->flags & DL_FLAG_PM_RUNTIME)) |
294 | continue; |
295 | |
296 | retval = pm_runtime_get_sync(dev: link->supplier); |
297 | /* Ignore suppliers with disabled runtime PM. */ |
298 | if (retval < 0 && retval != -EACCES) { |
299 | pm_runtime_put_noidle(dev: link->supplier); |
300 | return retval; |
301 | } |
302 | refcount_inc(r: &link->rpm_active); |
303 | } |
304 | return 0; |
305 | } |
306 | |
307 | /** |
308 | * pm_runtime_release_supplier - Drop references to device link's supplier. |
309 | * @link: Target device link. |
310 | * |
311 | * Drop all runtime PM references associated with @link to its supplier device. |
312 | */ |
313 | void pm_runtime_release_supplier(struct device_link *link) |
314 | { |
315 | struct device *supplier = link->supplier; |
316 | |
317 | /* |
318 | * The additional power.usage_count check is a safety net in case |
319 | * the rpm_active refcount becomes saturated, in which case |
320 | * refcount_dec_not_one() would return true forever, but it is not |
321 | * strictly necessary. |
322 | */ |
323 | while (refcount_dec_not_one(r: &link->rpm_active) && |
324 | atomic_read(v: &supplier->power.usage_count) > 0) |
325 | pm_runtime_put_noidle(dev: supplier); |
326 | } |
327 | |
328 | static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend) |
329 | { |
330 | struct device_link *link; |
331 | |
332 | list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, |
333 | device_links_read_lock_held()) { |
334 | pm_runtime_release_supplier(link); |
335 | if (try_to_suspend) |
336 | pm_request_idle(dev: link->supplier); |
337 | } |
338 | } |
339 | |
340 | static void rpm_put_suppliers(struct device *dev) |
341 | { |
342 | __rpm_put_suppliers(dev, try_to_suspend: true); |
343 | } |
344 | |
345 | static void rpm_suspend_suppliers(struct device *dev) |
346 | { |
347 | struct device_link *link; |
348 | int idx = device_links_read_lock(); |
349 | |
350 | list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, |
351 | device_links_read_lock_held()) |
352 | pm_request_idle(dev: link->supplier); |
353 | |
354 | device_links_read_unlock(idx); |
355 | } |
356 | |
357 | /** |
358 | * __rpm_callback - Run a given runtime PM callback for a given device. |
359 | * @cb: Runtime PM callback to run. |
360 | * @dev: Device to run the callback for. |
361 | */ |
362 | static int __rpm_callback(int (*cb)(struct device *), struct device *dev) |
363 | __releases(&dev->power.lock) __acquires(&dev->power.lock) |
364 | { |
365 | int retval = 0, idx; |
366 | bool use_links = dev->power.links_count > 0; |
367 | |
368 | if (dev->power.irq_safe) { |
369 | spin_unlock(lock: &dev->power.lock); |
370 | } else { |
371 | spin_unlock_irq(lock: &dev->power.lock); |
372 | |
373 | /* |
374 | * Resume suppliers if necessary. |
375 | * |
376 | * The device's runtime PM status cannot change until this |
377 | * routine returns, so it is safe to read the status outside of |
378 | * the lock. |
379 | */ |
380 | if (use_links && dev->power.runtime_status == RPM_RESUMING) { |
381 | idx = device_links_read_lock(); |
382 | |
383 | retval = rpm_get_suppliers(dev); |
384 | if (retval) { |
385 | rpm_put_suppliers(dev); |
386 | goto fail; |
387 | } |
388 | |
389 | device_links_read_unlock(idx); |
390 | } |
391 | } |
392 | |
393 | if (cb) |
394 | retval = cb(dev); |
395 | |
396 | if (dev->power.irq_safe) { |
397 | spin_lock(lock: &dev->power.lock); |
398 | } else { |
399 | /* |
400 | * If the device is suspending and the callback has returned |
401 | * success, drop the usage counters of the suppliers that have |
402 | * been reference counted on its resume. |
403 | * |
404 | * Do that if resume fails too. |
405 | */ |
406 | if (use_links && |
407 | ((dev->power.runtime_status == RPM_SUSPENDING && !retval) || |
408 | (dev->power.runtime_status == RPM_RESUMING && retval))) { |
409 | idx = device_links_read_lock(); |
410 | |
411 | __rpm_put_suppliers(dev, try_to_suspend: false); |
412 | |
413 | fail: |
414 | device_links_read_unlock(idx); |
415 | } |
416 | |
417 | spin_lock_irq(lock: &dev->power.lock); |
418 | } |
419 | |
420 | return retval; |
421 | } |
422 | |
423 | /** |
424 | * rpm_callback - Run a given runtime PM callback for a given device. |
425 | * @cb: Runtime PM callback to run. |
426 | * @dev: Device to run the callback for. |
427 | */ |
428 | static int rpm_callback(int (*cb)(struct device *), struct device *dev) |
429 | { |
430 | int retval; |
431 | |
432 | if (dev->power.memalloc_noio) { |
433 | unsigned int noio_flag; |
434 | |
435 | /* |
436 | * Deadlock might be caused if memory allocation with |
437 | * GFP_KERNEL happens inside runtime_suspend and |
438 | * runtime_resume callbacks of one block device's |
439 | * ancestor or the block device itself. Network |
440 | * device might be thought as part of iSCSI block |
441 | * device, so network device and its ancestor should |
442 | * be marked as memalloc_noio too. |
443 | */ |
444 | noio_flag = memalloc_noio_save(); |
445 | retval = __rpm_callback(cb, dev); |
446 | memalloc_noio_restore(flags: noio_flag); |
447 | } else { |
448 | retval = __rpm_callback(cb, dev); |
449 | } |
450 | |
451 | dev->power.runtime_error = retval; |
452 | return retval != -EACCES ? retval : -EIO; |
453 | } |
454 | |
455 | /** |
456 | * rpm_idle - Notify device bus type if the device can be suspended. |
457 | * @dev: Device to notify the bus type about. |
458 | * @rpmflags: Flag bits. |
459 | * |
460 | * Check if the device's runtime PM status allows it to be suspended. If |
461 | * another idle notification has been started earlier, return immediately. If |
462 | * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise |
463 | * run the ->runtime_idle() callback directly. If the ->runtime_idle callback |
464 | * doesn't exist or if it returns 0, call rpm_suspend with the RPM_AUTO flag. |
465 | * |
466 | * This function must be called under dev->power.lock with interrupts disabled. |
467 | */ |
468 | static int rpm_idle(struct device *dev, int rpmflags) |
469 | { |
470 | int (*callback)(struct device *); |
471 | int retval; |
472 | |
473 | trace_rpm_idle(dev, flags: rpmflags); |
474 | retval = rpm_check_suspend_allowed(dev); |
475 | if (retval < 0) |
476 | ; /* Conditions are wrong. */ |
477 | |
478 | /* Idle notifications are allowed only in the RPM_ACTIVE state. */ |
479 | else if (dev->power.runtime_status != RPM_ACTIVE) |
480 | retval = -EAGAIN; |
481 | |
482 | /* |
483 | * Any pending request other than an idle notification takes |
484 | * precedence over us, except that the timer may be running. |
485 | */ |
486 | else if (dev->power.request_pending && |
487 | dev->power.request > RPM_REQ_IDLE) |
488 | retval = -EAGAIN; |
489 | |
490 | /* Act as though RPM_NOWAIT is always set. */ |
491 | else if (dev->power.idle_notification) |
492 | retval = -EINPROGRESS; |
493 | |
494 | if (retval) |
495 | goto out; |
496 | |
497 | /* Pending requests need to be canceled. */ |
498 | dev->power.request = RPM_REQ_NONE; |
499 | |
500 | callback = RPM_GET_CALLBACK(dev, runtime_idle); |
501 | |
502 | /* If no callback assume success. */ |
503 | if (!callback || dev->power.no_callbacks) |
504 | goto out; |
505 | |
506 | /* Carry out an asynchronous or a synchronous idle notification. */ |
507 | if (rpmflags & RPM_ASYNC) { |
508 | dev->power.request = RPM_REQ_IDLE; |
509 | if (!dev->power.request_pending) { |
510 | dev->power.request_pending = true; |
511 | queue_work(wq: pm_wq, work: &dev->power.work); |
512 | } |
513 | trace_rpm_return_int(dev, _THIS_IP_, ret: 0); |
514 | return 0; |
515 | } |
516 | |
517 | dev->power.idle_notification = true; |
518 | |
519 | if (dev->power.irq_safe) |
520 | spin_unlock(lock: &dev->power.lock); |
521 | else |
522 | spin_unlock_irq(lock: &dev->power.lock); |
523 | |
524 | retval = callback(dev); |
525 | |
526 | if (dev->power.irq_safe) |
527 | spin_lock(lock: &dev->power.lock); |
528 | else |
529 | spin_lock_irq(lock: &dev->power.lock); |
530 | |
531 | dev->power.idle_notification = false; |
532 | wake_up_all(&dev->power.wait_queue); |
533 | |
534 | out: |
535 | trace_rpm_return_int(dev, _THIS_IP_, ret: retval); |
536 | return retval ? retval : rpm_suspend(dev, rpmflags: rpmflags | RPM_AUTO); |
537 | } |
538 | |
539 | /** |
540 | * rpm_suspend - Carry out runtime suspend of given device. |
541 | * @dev: Device to suspend. |
542 | * @rpmflags: Flag bits. |
543 | * |
544 | * Check if the device's runtime PM status allows it to be suspended. |
545 | * Cancel a pending idle notification, autosuspend or suspend. If |
546 | * another suspend has been started earlier, either return immediately |
547 | * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC |
548 | * flags. If the RPM_ASYNC flag is set then queue a suspend request; |
549 | * otherwise run the ->runtime_suspend() callback directly. When |
550 | * ->runtime_suspend succeeded, if a deferred resume was requested while |
551 | * the callback was running then carry it out, otherwise send an idle |
552 | * notification for its parent (if the suspend succeeded and both |
553 | * ignore_children of parent->power and irq_safe of dev->power are not set). |
554 | * If ->runtime_suspend failed with -EAGAIN or -EBUSY, and if the RPM_AUTO |
555 | * flag is set and the next autosuspend-delay expiration time is in the |
556 | * future, schedule another autosuspend attempt. |
557 | * |
558 | * This function must be called under dev->power.lock with interrupts disabled. |
559 | */ |
560 | static int rpm_suspend(struct device *dev, int rpmflags) |
561 | __releases(&dev->power.lock) __acquires(&dev->power.lock) |
562 | { |
563 | int (*callback)(struct device *); |
564 | struct device *parent = NULL; |
565 | int retval; |
566 | |
567 | trace_rpm_suspend(dev, flags: rpmflags); |
568 | |
569 | repeat: |
570 | retval = rpm_check_suspend_allowed(dev); |
571 | if (retval < 0) |
572 | goto out; /* Conditions are wrong. */ |
573 | |
574 | /* Synchronous suspends are not allowed in the RPM_RESUMING state. */ |
575 | if (dev->power.runtime_status == RPM_RESUMING && !(rpmflags & RPM_ASYNC)) |
576 | retval = -EAGAIN; |
577 | |
578 | if (retval) |
579 | goto out; |
580 | |
581 | /* If the autosuspend_delay time hasn't expired yet, reschedule. */ |
582 | if ((rpmflags & RPM_AUTO) && dev->power.runtime_status != RPM_SUSPENDING) { |
583 | u64 expires = pm_runtime_autosuspend_expiration(dev); |
584 | |
585 | if (expires != 0) { |
586 | /* Pending requests need to be canceled. */ |
587 | dev->power.request = RPM_REQ_NONE; |
588 | |
589 | /* |
590 | * Optimization: If the timer is already running and is |
591 | * set to expire at or before the autosuspend delay, |
592 | * avoid the overhead of resetting it. Just let it |
593 | * expire; pm_suspend_timer_fn() will take care of the |
594 | * rest. |
595 | */ |
596 | if (!(dev->power.timer_expires && |
597 | dev->power.timer_expires <= expires)) { |
598 | /* |
599 | * We add a slack of 25% to gather wakeups |
600 | * without sacrificing the granularity. |
601 | */ |
602 | u64 slack = (u64)READ_ONCE(dev->power.autosuspend_delay) * |
603 | (NSEC_PER_MSEC >> 2); |
604 | |
605 | dev->power.timer_expires = expires; |
606 | hrtimer_start_range_ns(timer: &dev->power.suspend_timer, |
607 | tim: ns_to_ktime(ns: expires), |
608 | range_ns: slack, |
609 | mode: HRTIMER_MODE_ABS); |
610 | } |
611 | dev->power.timer_autosuspends = 1; |
612 | goto out; |
613 | } |
614 | } |
615 | |
616 | /* Other scheduled or pending requests need to be canceled. */ |
617 | pm_runtime_cancel_pending(dev); |
618 | |
619 | if (dev->power.runtime_status == RPM_SUSPENDING) { |
620 | DEFINE_WAIT(wait); |
621 | |
622 | if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) { |
623 | retval = -EINPROGRESS; |
624 | goto out; |
625 | } |
626 | |
627 | if (dev->power.irq_safe) { |
628 | spin_unlock(lock: &dev->power.lock); |
629 | |
630 | cpu_relax(); |
631 | |
632 | spin_lock(lock: &dev->power.lock); |
633 | goto repeat; |
634 | } |
635 | |
636 | /* Wait for the other suspend running in parallel with us. */ |
637 | for (;;) { |
638 | prepare_to_wait(wq_head: &dev->power.wait_queue, wq_entry: &wait, |
639 | TASK_UNINTERRUPTIBLE); |
640 | if (dev->power.runtime_status != RPM_SUSPENDING) |
641 | break; |
642 | |
643 | spin_unlock_irq(lock: &dev->power.lock); |
644 | |
645 | schedule(); |
646 | |
647 | spin_lock_irq(lock: &dev->power.lock); |
648 | } |
649 | finish_wait(wq_head: &dev->power.wait_queue, wq_entry: &wait); |
650 | goto repeat; |
651 | } |
652 | |
653 | if (dev->power.no_callbacks) |
654 | goto no_callback; /* Assume success. */ |
655 | |
656 | /* Carry out an asynchronous or a synchronous suspend. */ |
657 | if (rpmflags & RPM_ASYNC) { |
658 | dev->power.request = (rpmflags & RPM_AUTO) ? |
659 | RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND; |
660 | if (!dev->power.request_pending) { |
661 | dev->power.request_pending = true; |
662 | queue_work(wq: pm_wq, work: &dev->power.work); |
663 | } |
664 | goto out; |
665 | } |
666 | |
667 | __update_runtime_status(dev, status: RPM_SUSPENDING); |
668 | |
669 | callback = RPM_GET_CALLBACK(dev, runtime_suspend); |
670 | |
671 | dev_pm_enable_wake_irq_check(dev, can_change_status: true); |
672 | retval = rpm_callback(cb: callback, dev); |
673 | if (retval) |
674 | goto fail; |
675 | |
676 | dev_pm_enable_wake_irq_complete(dev); |
677 | |
678 | no_callback: |
679 | __update_runtime_status(dev, status: RPM_SUSPENDED); |
680 | pm_runtime_deactivate_timer(dev); |
681 | |
682 | if (dev->parent) { |
683 | parent = dev->parent; |
684 | atomic_add_unless(v: &parent->power.child_count, a: -1, u: 0); |
685 | } |
686 | wake_up_all(&dev->power.wait_queue); |
687 | |
688 | if (dev->power.deferred_resume) { |
689 | dev->power.deferred_resume = false; |
690 | rpm_resume(dev, rpmflags: 0); |
691 | retval = -EAGAIN; |
692 | goto out; |
693 | } |
694 | |
695 | if (dev->power.irq_safe) |
696 | goto out; |
697 | |
698 | /* Maybe the parent is now able to suspend. */ |
699 | if (parent && !parent->power.ignore_children) { |
700 | spin_unlock(lock: &dev->power.lock); |
701 | |
702 | spin_lock(lock: &parent->power.lock); |
703 | rpm_idle(dev: parent, RPM_ASYNC); |
704 | spin_unlock(lock: &parent->power.lock); |
705 | |
706 | spin_lock(lock: &dev->power.lock); |
707 | } |
708 | /* Maybe the suppliers are now able to suspend. */ |
709 | if (dev->power.links_count > 0) { |
710 | spin_unlock_irq(lock: &dev->power.lock); |
711 | |
712 | rpm_suspend_suppliers(dev); |
713 | |
714 | spin_lock_irq(lock: &dev->power.lock); |
715 | } |
716 | |
717 | out: |
718 | trace_rpm_return_int(dev, _THIS_IP_, ret: retval); |
719 | |
720 | return retval; |
721 | |
722 | fail: |
723 | dev_pm_disable_wake_irq_check(dev, cond_disable: true); |
724 | __update_runtime_status(dev, status: RPM_ACTIVE); |
725 | dev->power.deferred_resume = false; |
726 | wake_up_all(&dev->power.wait_queue); |
727 | |
728 | if (retval == -EAGAIN || retval == -EBUSY) { |
729 | dev->power.runtime_error = 0; |
730 | |
731 | /* |
732 | * If the callback routine failed an autosuspend, and |
733 | * if the last_busy time has been updated so that there |
734 | * is a new autosuspend expiration time, automatically |
735 | * reschedule another autosuspend. |
736 | */ |
737 | if ((rpmflags & RPM_AUTO) && |
738 | pm_runtime_autosuspend_expiration(dev) != 0) |
739 | goto repeat; |
740 | } else { |
741 | pm_runtime_cancel_pending(dev); |
742 | } |
743 | goto out; |
744 | } |
745 | |
746 | /** |
747 | * rpm_resume - Carry out runtime resume of given device. |
748 | * @dev: Device to resume. |
749 | * @rpmflags: Flag bits. |
750 | * |
751 | * Check if the device's runtime PM status allows it to be resumed. Cancel |
752 | * any scheduled or pending requests. If another resume has been started |
753 | * earlier, either return immediately or wait for it to finish, depending on the |
754 | * RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in |
755 | * parallel with this function, either tell the other process to resume after |
756 | * suspending (deferred_resume) or wait for it to finish. If the RPM_ASYNC |
757 | * flag is set then queue a resume request; otherwise run the |
758 | * ->runtime_resume() callback directly. Queue an idle notification for the |
759 | * device if the resume succeeded. |
760 | * |
761 | * This function must be called under dev->power.lock with interrupts disabled. |
762 | */ |
763 | static int rpm_resume(struct device *dev, int rpmflags) |
764 | __releases(&dev->power.lock) __acquires(&dev->power.lock) |
765 | { |
766 | int (*callback)(struct device *); |
767 | struct device *parent = NULL; |
768 | int retval = 0; |
769 | |
770 | trace_rpm_resume(dev, flags: rpmflags); |
771 | |
772 | repeat: |
773 | if (dev->power.runtime_error) { |
774 | retval = -EINVAL; |
775 | } else if (dev->power.disable_depth > 0) { |
776 | if (dev->power.runtime_status == RPM_ACTIVE && |
777 | dev->power.last_status == RPM_ACTIVE) |
778 | retval = 1; |
779 | else |
780 | retval = -EACCES; |
781 | } |
782 | if (retval) |
783 | goto out; |
784 | |
785 | /* |
786 | * Other scheduled or pending requests need to be canceled. Small |
787 | * optimization: If an autosuspend timer is running, leave it running |
788 | * rather than cancelling it now only to restart it again in the near |
789 | * future. |
790 | */ |
791 | dev->power.request = RPM_REQ_NONE; |
792 | if (!dev->power.timer_autosuspends) |
793 | pm_runtime_deactivate_timer(dev); |
794 | |
795 | if (dev->power.runtime_status == RPM_ACTIVE) { |
796 | retval = 1; |
797 | goto out; |
798 | } |
799 | |
800 | if (dev->power.runtime_status == RPM_RESUMING || |
801 | dev->power.runtime_status == RPM_SUSPENDING) { |
802 | DEFINE_WAIT(wait); |
803 | |
804 | if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) { |
805 | if (dev->power.runtime_status == RPM_SUSPENDING) { |
806 | dev->power.deferred_resume = true; |
807 | if (rpmflags & RPM_NOWAIT) |
808 | retval = -EINPROGRESS; |
809 | } else { |
810 | retval = -EINPROGRESS; |
811 | } |
812 | goto out; |
813 | } |
814 | |
815 | if (dev->power.irq_safe) { |
816 | spin_unlock(lock: &dev->power.lock); |
817 | |
818 | cpu_relax(); |
819 | |
820 | spin_lock(lock: &dev->power.lock); |
821 | goto repeat; |
822 | } |
823 | |
824 | /* Wait for the operation carried out in parallel with us. */ |
825 | for (;;) { |
826 | prepare_to_wait(wq_head: &dev->power.wait_queue, wq_entry: &wait, |
827 | TASK_UNINTERRUPTIBLE); |
828 | if (dev->power.runtime_status != RPM_RESUMING && |
829 | dev->power.runtime_status != RPM_SUSPENDING) |
830 | break; |
831 | |
832 | spin_unlock_irq(lock: &dev->power.lock); |
833 | |
834 | schedule(); |
835 | |
836 | spin_lock_irq(lock: &dev->power.lock); |
837 | } |
838 | finish_wait(wq_head: &dev->power.wait_queue, wq_entry: &wait); |
839 | goto repeat; |
840 | } |
841 | |
842 | /* |
843 | * See if we can skip waking up the parent. This is safe only if |
844 | * power.no_callbacks is set, because otherwise we don't know whether |
845 | * the resume will actually succeed. |
846 | */ |
847 | if (dev->power.no_callbacks && !parent && dev->parent) { |
848 | spin_lock_nested(&dev->parent->power.lock, SINGLE_DEPTH_NESTING); |
849 | if (dev->parent->power.disable_depth > 0 || |
850 | dev->parent->power.ignore_children || |
851 | dev->parent->power.runtime_status == RPM_ACTIVE) { |
852 | atomic_inc(v: &dev->parent->power.child_count); |
853 | spin_unlock(lock: &dev->parent->power.lock); |
854 | retval = 1; |
855 | goto no_callback; /* Assume success. */ |
856 | } |
857 | spin_unlock(lock: &dev->parent->power.lock); |
858 | } |
859 | |
860 | /* Carry out an asynchronous or a synchronous resume. */ |
861 | if (rpmflags & RPM_ASYNC) { |
862 | dev->power.request = RPM_REQ_RESUME; |
863 | if (!dev->power.request_pending) { |
864 | dev->power.request_pending = true; |
865 | queue_work(wq: pm_wq, work: &dev->power.work); |
866 | } |
867 | retval = 0; |
868 | goto out; |
869 | } |
870 | |
871 | if (!parent && dev->parent) { |
872 | /* |
873 | * Increment the parent's usage counter and resume it if |
874 | * necessary. Not needed if dev is irq-safe; then the |
875 | * parent is permanently resumed. |
876 | */ |
877 | parent = dev->parent; |
878 | if (dev->power.irq_safe) |
879 | goto skip_parent; |
880 | |
881 | spin_unlock(lock: &dev->power.lock); |
882 | |
883 | pm_runtime_get_noresume(dev: parent); |
884 | |
885 | spin_lock(lock: &parent->power.lock); |
886 | /* |
887 | * Resume the parent if it has runtime PM enabled and not been |
888 | * set to ignore its children. |
889 | */ |
890 | if (!parent->power.disable_depth && |
891 | !parent->power.ignore_children) { |
892 | rpm_resume(dev: parent, rpmflags: 0); |
893 | if (parent->power.runtime_status != RPM_ACTIVE) |
894 | retval = -EBUSY; |
895 | } |
896 | spin_unlock(lock: &parent->power.lock); |
897 | |
898 | spin_lock(lock: &dev->power.lock); |
899 | if (retval) |
900 | goto out; |
901 | |
902 | goto repeat; |
903 | } |
904 | skip_parent: |
905 | |
906 | if (dev->power.no_callbacks) |
907 | goto no_callback; /* Assume success. */ |
908 | |
909 | __update_runtime_status(dev, status: RPM_RESUMING); |
910 | |
911 | callback = RPM_GET_CALLBACK(dev, runtime_resume); |
912 | |
913 | dev_pm_disable_wake_irq_check(dev, cond_disable: false); |
914 | retval = rpm_callback(cb: callback, dev); |
915 | if (retval) { |
916 | __update_runtime_status(dev, status: RPM_SUSPENDED); |
917 | pm_runtime_cancel_pending(dev); |
918 | dev_pm_enable_wake_irq_check(dev, can_change_status: false); |
919 | } else { |
920 | no_callback: |
921 | __update_runtime_status(dev, status: RPM_ACTIVE); |
922 | pm_runtime_mark_last_busy(dev); |
923 | if (parent) |
924 | atomic_inc(v: &parent->power.child_count); |
925 | } |
926 | wake_up_all(&dev->power.wait_queue); |
927 | |
928 | if (retval >= 0) |
929 | rpm_idle(dev, RPM_ASYNC); |
930 | |
931 | out: |
932 | if (parent && !dev->power.irq_safe) { |
933 | spin_unlock_irq(lock: &dev->power.lock); |
934 | |
935 | pm_runtime_put(dev: parent); |
936 | |
937 | spin_lock_irq(lock: &dev->power.lock); |
938 | } |
939 | |
940 | trace_rpm_return_int(dev, _THIS_IP_, ret: retval); |
941 | |
942 | return retval; |
943 | } |
944 | |
945 | /** |
946 | * pm_runtime_work - Universal runtime PM work function. |
947 | * @work: Work structure used for scheduling the execution of this function. |
948 | * |
949 | * Use @work to get the device object the work is to be done for, determine what |
950 | * is to be done and execute the appropriate runtime PM function. |
951 | */ |
952 | static void pm_runtime_work(struct work_struct *work) |
953 | { |
954 | struct device *dev = container_of(work, struct device, power.work); |
955 | enum rpm_request req; |
956 | |
957 | spin_lock_irq(lock: &dev->power.lock); |
958 | |
959 | if (!dev->power.request_pending) |
960 | goto out; |
961 | |
962 | req = dev->power.request; |
963 | dev->power.request = RPM_REQ_NONE; |
964 | dev->power.request_pending = false; |
965 | |
966 | switch (req) { |
967 | case RPM_REQ_NONE: |
968 | break; |
969 | case RPM_REQ_IDLE: |
970 | rpm_idle(dev, RPM_NOWAIT); |
971 | break; |
972 | case RPM_REQ_SUSPEND: |
973 | rpm_suspend(dev, RPM_NOWAIT); |
974 | break; |
975 | case RPM_REQ_AUTOSUSPEND: |
976 | rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO); |
977 | break; |
978 | case RPM_REQ_RESUME: |
979 | rpm_resume(dev, RPM_NOWAIT); |
980 | break; |
981 | } |
982 | |
983 | out: |
984 | spin_unlock_irq(lock: &dev->power.lock); |
985 | } |
986 | |
987 | /** |
988 | * pm_suspend_timer_fn - Timer function for pm_schedule_suspend(). |
989 | * @timer: hrtimer used by pm_schedule_suspend(). |
990 | * |
991 | * Check if the time is right and queue a suspend request. |
992 | */ |
993 | static enum hrtimer_restart pm_suspend_timer_fn(struct hrtimer *timer) |
994 | { |
995 | struct device *dev = container_of(timer, struct device, power.suspend_timer); |
996 | unsigned long flags; |
997 | u64 expires; |
998 | |
999 | spin_lock_irqsave(&dev->power.lock, flags); |
1000 | |
1001 | expires = dev->power.timer_expires; |
1002 | /* |
1003 | * If 'expires' is after the current time, we've been called |
1004 | * too early. |
1005 | */ |
1006 | if (expires > 0 && expires < ktime_get_mono_fast_ns()) { |
1007 | dev->power.timer_expires = 0; |
1008 | rpm_suspend(dev, rpmflags: dev->power.timer_autosuspends ? |
1009 | (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC); |
1010 | } |
1011 | |
1012 | spin_unlock_irqrestore(lock: &dev->power.lock, flags); |
1013 | |
1014 | return HRTIMER_NORESTART; |
1015 | } |
1016 | |
1017 | /** |
1018 | * pm_schedule_suspend - Set up a timer to submit a suspend request in future. |
1019 | * @dev: Device to suspend. |
1020 | * @delay: Time to wait before submitting a suspend request, in milliseconds. |
1021 | */ |
1022 | int pm_schedule_suspend(struct device *dev, unsigned int delay) |
1023 | { |
1024 | unsigned long flags; |
1025 | u64 expires; |
1026 | int retval; |
1027 | |
1028 | spin_lock_irqsave(&dev->power.lock, flags); |
1029 | |
1030 | if (!delay) { |
1031 | retval = rpm_suspend(dev, RPM_ASYNC); |
1032 | goto out; |
1033 | } |
1034 | |
1035 | retval = rpm_check_suspend_allowed(dev); |
1036 | if (retval) |
1037 | goto out; |
1038 | |
1039 | /* Other scheduled or pending requests need to be canceled. */ |
1040 | pm_runtime_cancel_pending(dev); |
1041 | |
1042 | expires = ktime_get_mono_fast_ns() + (u64)delay * NSEC_PER_MSEC; |
1043 | dev->power.timer_expires = expires; |
1044 | dev->power.timer_autosuspends = 0; |
1045 | hrtimer_start(timer: &dev->power.suspend_timer, tim: expires, mode: HRTIMER_MODE_ABS); |
1046 | |
1047 | out: |
1048 | spin_unlock_irqrestore(lock: &dev->power.lock, flags); |
1049 | |
1050 | return retval; |
1051 | } |
1052 | EXPORT_SYMBOL_GPL(pm_schedule_suspend); |
1053 | |
1054 | static int rpm_drop_usage_count(struct device *dev) |
1055 | { |
1056 | int ret; |
1057 | |
1058 | ret = atomic_sub_return(i: 1, v: &dev->power.usage_count); |
1059 | if (ret >= 0) |
1060 | return ret; |
1061 | |
1062 | /* |
1063 | * Because rpm_resume() does not check the usage counter, it will resume |
1064 | * the device even if the usage counter is 0 or negative, so it is |
1065 | * sufficient to increment the usage counter here to reverse the change |
1066 | * made above. |
1067 | */ |
1068 | atomic_inc(v: &dev->power.usage_count); |
1069 | dev_warn(dev, "Runtime PM usage count underflow!\n" ); |
1070 | return -EINVAL; |
1071 | } |
1072 | |
1073 | /** |
1074 | * __pm_runtime_idle - Entry point for runtime idle operations. |
1075 | * @dev: Device to send idle notification for. |
1076 | * @rpmflags: Flag bits. |
1077 | * |
1078 | * If the RPM_GET_PUT flag is set, decrement the device's usage count and |
1079 | * return immediately if it is larger than zero (if it becomes negative, log a |
1080 | * warning, increment it, and return an error). Then carry out an idle |
1081 | * notification, either synchronous or asynchronous. |
1082 | * |
1083 | * This routine may be called in atomic context if the RPM_ASYNC flag is set, |
1084 | * or if pm_runtime_irq_safe() has been called. |
1085 | */ |
1086 | int __pm_runtime_idle(struct device *dev, int rpmflags) |
1087 | { |
1088 | unsigned long flags; |
1089 | int retval; |
1090 | |
1091 | if (rpmflags & RPM_GET_PUT) { |
1092 | retval = rpm_drop_usage_count(dev); |
1093 | if (retval < 0) { |
1094 | return retval; |
1095 | } else if (retval > 0) { |
1096 | trace_rpm_usage(dev, flags: rpmflags); |
1097 | return 0; |
1098 | } |
1099 | } |
1100 | |
1101 | might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe); |
1102 | |
1103 | spin_lock_irqsave(&dev->power.lock, flags); |
1104 | retval = rpm_idle(dev, rpmflags); |
1105 | spin_unlock_irqrestore(lock: &dev->power.lock, flags); |
1106 | |
1107 | return retval; |
1108 | } |
1109 | EXPORT_SYMBOL_GPL(__pm_runtime_idle); |
1110 | |
1111 | /** |
1112 | * __pm_runtime_suspend - Entry point for runtime put/suspend operations. |
1113 | * @dev: Device to suspend. |
1114 | * @rpmflags: Flag bits. |
1115 | * |
1116 | * If the RPM_GET_PUT flag is set, decrement the device's usage count and |
1117 | * return immediately if it is larger than zero (if it becomes negative, log a |
1118 | * warning, increment it, and return an error). Then carry out a suspend, |
1119 | * either synchronous or asynchronous. |
1120 | * |
1121 | * This routine may be called in atomic context if the RPM_ASYNC flag is set, |
1122 | * or if pm_runtime_irq_safe() has been called. |
1123 | */ |
1124 | int __pm_runtime_suspend(struct device *dev, int rpmflags) |
1125 | { |
1126 | unsigned long flags; |
1127 | int retval; |
1128 | |
1129 | if (rpmflags & RPM_GET_PUT) { |
1130 | retval = rpm_drop_usage_count(dev); |
1131 | if (retval < 0) { |
1132 | return retval; |
1133 | } else if (retval > 0) { |
1134 | trace_rpm_usage(dev, flags: rpmflags); |
1135 | return 0; |
1136 | } |
1137 | } |
1138 | |
1139 | might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe); |
1140 | |
1141 | spin_lock_irqsave(&dev->power.lock, flags); |
1142 | retval = rpm_suspend(dev, rpmflags); |
1143 | spin_unlock_irqrestore(lock: &dev->power.lock, flags); |
1144 | |
1145 | return retval; |
1146 | } |
1147 | EXPORT_SYMBOL_GPL(__pm_runtime_suspend); |
1148 | |
1149 | /** |
1150 | * __pm_runtime_resume - Entry point for runtime resume operations. |
1151 | * @dev: Device to resume. |
1152 | * @rpmflags: Flag bits. |
1153 | * |
1154 | * If the RPM_GET_PUT flag is set, increment the device's usage count. Then |
1155 | * carry out a resume, either synchronous or asynchronous. |
1156 | * |
1157 | * This routine may be called in atomic context if the RPM_ASYNC flag is set, |
1158 | * or if pm_runtime_irq_safe() has been called. |
1159 | */ |
1160 | int __pm_runtime_resume(struct device *dev, int rpmflags) |
1161 | { |
1162 | unsigned long flags; |
1163 | int retval; |
1164 | |
1165 | might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe && |
1166 | dev->power.runtime_status != RPM_ACTIVE); |
1167 | |
1168 | if (rpmflags & RPM_GET_PUT) |
1169 | atomic_inc(v: &dev->power.usage_count); |
1170 | |
1171 | spin_lock_irqsave(&dev->power.lock, flags); |
1172 | retval = rpm_resume(dev, rpmflags); |
1173 | spin_unlock_irqrestore(lock: &dev->power.lock, flags); |
1174 | |
1175 | return retval; |
1176 | } |
1177 | EXPORT_SYMBOL_GPL(__pm_runtime_resume); |
1178 | |
1179 | /** |
1180 | * pm_runtime_get_conditional - Conditionally bump up device usage counter. |
1181 | * @dev: Device to handle. |
1182 | * @ign_usage_count: Whether or not to look at the current usage counter value. |
1183 | * |
1184 | * Return -EINVAL if runtime PM is disabled for @dev. |
1185 | * |
1186 | * Otherwise, if the runtime PM status of @dev is %RPM_ACTIVE and either |
1187 | * @ign_usage_count is %true or the runtime PM usage counter of @dev is not |
1188 | * zero, increment the usage counter of @dev and return 1. Otherwise, return 0 |
1189 | * without changing the usage counter. |
1190 | * |
1191 | * If @ign_usage_count is %true, this function can be used to prevent suspending |
1192 | * the device when its runtime PM status is %RPM_ACTIVE. |
1193 | * |
1194 | * If @ign_usage_count is %false, this function can be used to prevent |
1195 | * suspending the device when both its runtime PM status is %RPM_ACTIVE and its |
1196 | * runtime PM usage counter is not zero. |
1197 | * |
1198 | * The caller is responsible for decrementing the runtime PM usage counter of |
1199 | * @dev after this function has returned a positive value for it. |
1200 | */ |
1201 | static int pm_runtime_get_conditional(struct device *dev, bool ign_usage_count) |
1202 | { |
1203 | unsigned long flags; |
1204 | int retval; |
1205 | |
1206 | spin_lock_irqsave(&dev->power.lock, flags); |
1207 | if (dev->power.disable_depth > 0) { |
1208 | retval = -EINVAL; |
1209 | } else if (dev->power.runtime_status != RPM_ACTIVE) { |
1210 | retval = 0; |
1211 | } else if (ign_usage_count) { |
1212 | retval = 1; |
1213 | atomic_inc(v: &dev->power.usage_count); |
1214 | } else { |
1215 | retval = atomic_inc_not_zero(v: &dev->power.usage_count); |
1216 | } |
1217 | trace_rpm_usage(dev, flags: 0); |
1218 | spin_unlock_irqrestore(lock: &dev->power.lock, flags); |
1219 | |
1220 | return retval; |
1221 | } |
1222 | |
1223 | /** |
1224 | * pm_runtime_get_if_active - Bump up runtime PM usage counter if the device is |
1225 | * in active state |
1226 | * @dev: Target device. |
1227 | * |
1228 | * Increment the runtime PM usage counter of @dev if its runtime PM status is |
1229 | * %RPM_ACTIVE, in which case it returns 1. If the device is in a different |
1230 | * state, 0 is returned. -EINVAL is returned if runtime PM is disabled for the |
1231 | * device, in which case also the usage_count will remain unmodified. |
1232 | */ |
1233 | int pm_runtime_get_if_active(struct device *dev) |
1234 | { |
1235 | return pm_runtime_get_conditional(dev, ign_usage_count: true); |
1236 | } |
1237 | EXPORT_SYMBOL_GPL(pm_runtime_get_if_active); |
1238 | |
1239 | /** |
1240 | * pm_runtime_get_if_in_use - Conditionally bump up runtime PM usage counter. |
1241 | * @dev: Target device. |
1242 | * |
1243 | * Increment the runtime PM usage counter of @dev if its runtime PM status is |
1244 | * %RPM_ACTIVE and its runtime PM usage counter is greater than 0, in which case |
1245 | * it returns 1. If the device is in a different state or its usage_count is 0, |
1246 | * 0 is returned. -EINVAL is returned if runtime PM is disabled for the device, |
1247 | * in which case also the usage_count will remain unmodified. |
1248 | */ |
1249 | int pm_runtime_get_if_in_use(struct device *dev) |
1250 | { |
1251 | return pm_runtime_get_conditional(dev, ign_usage_count: false); |
1252 | } |
1253 | EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use); |
1254 | |
1255 | /** |
1256 | * __pm_runtime_set_status - Set runtime PM status of a device. |
1257 | * @dev: Device to handle. |
1258 | * @status: New runtime PM status of the device. |
1259 | * |
1260 | * If runtime PM of the device is disabled or its power.runtime_error field is |
1261 | * different from zero, the status may be changed either to RPM_ACTIVE, or to |
1262 | * RPM_SUSPENDED, as long as that reflects the actual state of the device. |
1263 | * However, if the device has a parent and the parent is not active, and the |
1264 | * parent's power.ignore_children flag is unset, the device's status cannot be |
1265 | * set to RPM_ACTIVE, so -EBUSY is returned in that case. |
1266 | * |
1267 | * If successful, __pm_runtime_set_status() clears the power.runtime_error field |
1268 | * and the device parent's counter of unsuspended children is modified to |
1269 | * reflect the new status. If the new status is RPM_SUSPENDED, an idle |
1270 | * notification request for the parent is submitted. |
1271 | * |
1272 | * If @dev has any suppliers (as reflected by device links to them), and @status |
1273 | * is RPM_ACTIVE, they will be activated upfront and if the activation of one |
1274 | * of them fails, the status of @dev will be changed to RPM_SUSPENDED (instead |
1275 | * of the @status value) and the suppliers will be deacticated on exit. The |
1276 | * error returned by the failing supplier activation will be returned in that |
1277 | * case. |
1278 | */ |
1279 | int __pm_runtime_set_status(struct device *dev, unsigned int status) |
1280 | { |
1281 | struct device *parent = dev->parent; |
1282 | bool notify_parent = false; |
1283 | unsigned long flags; |
1284 | int error = 0; |
1285 | |
1286 | if (status != RPM_ACTIVE && status != RPM_SUSPENDED) |
1287 | return -EINVAL; |
1288 | |
1289 | spin_lock_irqsave(&dev->power.lock, flags); |
1290 | |
1291 | /* |
1292 | * Prevent PM-runtime from being enabled for the device or return an |
1293 | * error if it is enabled already and working. |
1294 | */ |
1295 | if (dev->power.runtime_error || dev->power.disable_depth) |
1296 | dev->power.disable_depth++; |
1297 | else |
1298 | error = -EAGAIN; |
1299 | |
1300 | spin_unlock_irqrestore(lock: &dev->power.lock, flags); |
1301 | |
1302 | if (error) |
1303 | return error; |
1304 | |
1305 | /* |
1306 | * If the new status is RPM_ACTIVE, the suppliers can be activated |
1307 | * upfront regardless of the current status, because next time |
1308 | * rpm_put_suppliers() runs, the rpm_active refcounts of the links |
1309 | * involved will be dropped down to one anyway. |
1310 | */ |
1311 | if (status == RPM_ACTIVE) { |
1312 | int idx = device_links_read_lock(); |
1313 | |
1314 | error = rpm_get_suppliers(dev); |
1315 | if (error) |
1316 | status = RPM_SUSPENDED; |
1317 | |
1318 | device_links_read_unlock(idx); |
1319 | } |
1320 | |
1321 | spin_lock_irqsave(&dev->power.lock, flags); |
1322 | |
1323 | if (dev->power.runtime_status == status || !parent) |
1324 | goto out_set; |
1325 | |
1326 | if (status == RPM_SUSPENDED) { |
1327 | atomic_add_unless(v: &parent->power.child_count, a: -1, u: 0); |
1328 | notify_parent = !parent->power.ignore_children; |
1329 | } else { |
1330 | spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING); |
1331 | |
1332 | /* |
1333 | * It is invalid to put an active child under a parent that is |
1334 | * not active, has runtime PM enabled and the |
1335 | * 'power.ignore_children' flag unset. |
1336 | */ |
1337 | if (!parent->power.disable_depth && |
1338 | !parent->power.ignore_children && |
1339 | parent->power.runtime_status != RPM_ACTIVE) { |
1340 | dev_err(dev, "runtime PM trying to activate child device %s but parent (%s) is not active\n" , |
1341 | dev_name(dev), |
1342 | dev_name(parent)); |
1343 | error = -EBUSY; |
1344 | } else if (dev->power.runtime_status == RPM_SUSPENDED) { |
1345 | atomic_inc(v: &parent->power.child_count); |
1346 | } |
1347 | |
1348 | spin_unlock(lock: &parent->power.lock); |
1349 | |
1350 | if (error) { |
1351 | status = RPM_SUSPENDED; |
1352 | goto out; |
1353 | } |
1354 | } |
1355 | |
1356 | out_set: |
1357 | __update_runtime_status(dev, status); |
1358 | if (!error) |
1359 | dev->power.runtime_error = 0; |
1360 | |
1361 | out: |
1362 | spin_unlock_irqrestore(lock: &dev->power.lock, flags); |
1363 | |
1364 | if (notify_parent) |
1365 | pm_request_idle(dev: parent); |
1366 | |
1367 | if (status == RPM_SUSPENDED) { |
1368 | int idx = device_links_read_lock(); |
1369 | |
1370 | rpm_put_suppliers(dev); |
1371 | |
1372 | device_links_read_unlock(idx); |
1373 | } |
1374 | |
1375 | pm_runtime_enable(dev); |
1376 | |
1377 | return error; |
1378 | } |
1379 | EXPORT_SYMBOL_GPL(__pm_runtime_set_status); |
1380 | |
1381 | /** |
1382 | * __pm_runtime_barrier - Cancel pending requests and wait for completions. |
1383 | * @dev: Device to handle. |
1384 | * |
1385 | * Flush all pending requests for the device from pm_wq and wait for all |
1386 | * runtime PM operations involving the device in progress to complete. |
1387 | * |
1388 | * Should be called under dev->power.lock with interrupts disabled. |
1389 | */ |
1390 | static void __pm_runtime_barrier(struct device *dev) |
1391 | { |
1392 | pm_runtime_deactivate_timer(dev); |
1393 | |
1394 | if (dev->power.request_pending) { |
1395 | dev->power.request = RPM_REQ_NONE; |
1396 | spin_unlock_irq(lock: &dev->power.lock); |
1397 | |
1398 | cancel_work_sync(work: &dev->power.work); |
1399 | |
1400 | spin_lock_irq(lock: &dev->power.lock); |
1401 | dev->power.request_pending = false; |
1402 | } |
1403 | |
1404 | if (dev->power.runtime_status == RPM_SUSPENDING || |
1405 | dev->power.runtime_status == RPM_RESUMING || |
1406 | dev->power.idle_notification) { |
1407 | DEFINE_WAIT(wait); |
1408 | |
1409 | /* Suspend, wake-up or idle notification in progress. */ |
1410 | for (;;) { |
1411 | prepare_to_wait(wq_head: &dev->power.wait_queue, wq_entry: &wait, |
1412 | TASK_UNINTERRUPTIBLE); |
1413 | if (dev->power.runtime_status != RPM_SUSPENDING |
1414 | && dev->power.runtime_status != RPM_RESUMING |
1415 | && !dev->power.idle_notification) |
1416 | break; |
1417 | spin_unlock_irq(lock: &dev->power.lock); |
1418 | |
1419 | schedule(); |
1420 | |
1421 | spin_lock_irq(lock: &dev->power.lock); |
1422 | } |
1423 | finish_wait(wq_head: &dev->power.wait_queue, wq_entry: &wait); |
1424 | } |
1425 | } |
1426 | |
1427 | /** |
1428 | * pm_runtime_barrier - Flush pending requests and wait for completions. |
1429 | * @dev: Device to handle. |
1430 | * |
1431 | * Prevent the device from being suspended by incrementing its usage counter and |
1432 | * if there's a pending resume request for the device, wake the device up. |
1433 | * Next, make sure that all pending requests for the device have been flushed |
1434 | * from pm_wq and wait for all runtime PM operations involving the device in |
1435 | * progress to complete. |
1436 | * |
1437 | * Return value: |
1438 | * 1, if there was a resume request pending and the device had to be woken up, |
1439 | * 0, otherwise |
1440 | */ |
1441 | int pm_runtime_barrier(struct device *dev) |
1442 | { |
1443 | int retval = 0; |
1444 | |
1445 | pm_runtime_get_noresume(dev); |
1446 | spin_lock_irq(lock: &dev->power.lock); |
1447 | |
1448 | if (dev->power.request_pending |
1449 | && dev->power.request == RPM_REQ_RESUME) { |
1450 | rpm_resume(dev, rpmflags: 0); |
1451 | retval = 1; |
1452 | } |
1453 | |
1454 | __pm_runtime_barrier(dev); |
1455 | |
1456 | spin_unlock_irq(lock: &dev->power.lock); |
1457 | pm_runtime_put_noidle(dev); |
1458 | |
1459 | return retval; |
1460 | } |
1461 | EXPORT_SYMBOL_GPL(pm_runtime_barrier); |
1462 | |
1463 | /** |
1464 | * __pm_runtime_disable - Disable runtime PM of a device. |
1465 | * @dev: Device to handle. |
1466 | * @check_resume: If set, check if there's a resume request for the device. |
1467 | * |
1468 | * Increment power.disable_depth for the device and if it was zero previously, |
1469 | * cancel all pending runtime PM requests for the device and wait for all |
1470 | * operations in progress to complete. The device can be either active or |
1471 | * suspended after its runtime PM has been disabled. |
1472 | * |
1473 | * If @check_resume is set and there's a resume request pending when |
1474 | * __pm_runtime_disable() is called and power.disable_depth is zero, the |
1475 | * function will wake up the device before disabling its runtime PM. |
1476 | */ |
1477 | void __pm_runtime_disable(struct device *dev, bool check_resume) |
1478 | { |
1479 | spin_lock_irq(lock: &dev->power.lock); |
1480 | |
1481 | if (dev->power.disable_depth > 0) { |
1482 | dev->power.disable_depth++; |
1483 | goto out; |
1484 | } |
1485 | |
1486 | /* |
1487 | * Wake up the device if there's a resume request pending, because that |
1488 | * means there probably is some I/O to process and disabling runtime PM |
1489 | * shouldn't prevent the device from processing the I/O. |
1490 | */ |
1491 | if (check_resume && dev->power.request_pending && |
1492 | dev->power.request == RPM_REQ_RESUME) { |
1493 | /* |
1494 | * Prevent suspends and idle notifications from being carried |
1495 | * out after we have woken up the device. |
1496 | */ |
1497 | pm_runtime_get_noresume(dev); |
1498 | |
1499 | rpm_resume(dev, rpmflags: 0); |
1500 | |
1501 | pm_runtime_put_noidle(dev); |
1502 | } |
1503 | |
1504 | /* Update time accounting before disabling PM-runtime. */ |
1505 | update_pm_runtime_accounting(dev); |
1506 | |
1507 | if (!dev->power.disable_depth++) { |
1508 | __pm_runtime_barrier(dev); |
1509 | dev->power.last_status = dev->power.runtime_status; |
1510 | } |
1511 | |
1512 | out: |
1513 | spin_unlock_irq(lock: &dev->power.lock); |
1514 | } |
1515 | EXPORT_SYMBOL_GPL(__pm_runtime_disable); |
1516 | |
1517 | /** |
1518 | * pm_runtime_enable - Enable runtime PM of a device. |
1519 | * @dev: Device to handle. |
1520 | */ |
1521 | void pm_runtime_enable(struct device *dev) |
1522 | { |
1523 | unsigned long flags; |
1524 | |
1525 | spin_lock_irqsave(&dev->power.lock, flags); |
1526 | |
1527 | if (!dev->power.disable_depth) { |
1528 | dev_warn(dev, "Unbalanced %s!\n" , __func__); |
1529 | goto out; |
1530 | } |
1531 | |
1532 | if (--dev->power.disable_depth > 0) |
1533 | goto out; |
1534 | |
1535 | dev->power.last_status = RPM_INVALID; |
1536 | dev->power.accounting_timestamp = ktime_get_mono_fast_ns(); |
1537 | |
1538 | if (dev->power.runtime_status == RPM_SUSPENDED && |
1539 | !dev->power.ignore_children && |
1540 | atomic_read(v: &dev->power.child_count) > 0) |
1541 | dev_warn(dev, "Enabling runtime PM for inactive device with active children\n" ); |
1542 | |
1543 | out: |
1544 | spin_unlock_irqrestore(lock: &dev->power.lock, flags); |
1545 | } |
1546 | EXPORT_SYMBOL_GPL(pm_runtime_enable); |
1547 | |
1548 | static void pm_runtime_disable_action(void *data) |
1549 | { |
1550 | pm_runtime_dont_use_autosuspend(dev: data); |
1551 | pm_runtime_disable(dev: data); |
1552 | } |
1553 | |
1554 | /** |
1555 | * devm_pm_runtime_enable - devres-enabled version of pm_runtime_enable. |
1556 | * |
1557 | * NOTE: this will also handle calling pm_runtime_dont_use_autosuspend() for |
1558 | * you at driver exit time if needed. |
1559 | * |
1560 | * @dev: Device to handle. |
1561 | */ |
1562 | int devm_pm_runtime_enable(struct device *dev) |
1563 | { |
1564 | pm_runtime_enable(dev); |
1565 | |
1566 | return devm_add_action_or_reset(dev, pm_runtime_disable_action, dev); |
1567 | } |
1568 | EXPORT_SYMBOL_GPL(devm_pm_runtime_enable); |
1569 | |
1570 | /** |
1571 | * pm_runtime_forbid - Block runtime PM of a device. |
1572 | * @dev: Device to handle. |
1573 | * |
1574 | * Increase the device's usage count and clear its power.runtime_auto flag, |
1575 | * so that it cannot be suspended at run time until pm_runtime_allow() is called |
1576 | * for it. |
1577 | */ |
1578 | void pm_runtime_forbid(struct device *dev) |
1579 | { |
1580 | spin_lock_irq(lock: &dev->power.lock); |
1581 | if (!dev->power.runtime_auto) |
1582 | goto out; |
1583 | |
1584 | dev->power.runtime_auto = false; |
1585 | atomic_inc(v: &dev->power.usage_count); |
1586 | rpm_resume(dev, rpmflags: 0); |
1587 | |
1588 | out: |
1589 | spin_unlock_irq(lock: &dev->power.lock); |
1590 | } |
1591 | EXPORT_SYMBOL_GPL(pm_runtime_forbid); |
1592 | |
1593 | /** |
1594 | * pm_runtime_allow - Unblock runtime PM of a device. |
1595 | * @dev: Device to handle. |
1596 | * |
1597 | * Decrease the device's usage count and set its power.runtime_auto flag. |
1598 | */ |
1599 | void pm_runtime_allow(struct device *dev) |
1600 | { |
1601 | int ret; |
1602 | |
1603 | spin_lock_irq(lock: &dev->power.lock); |
1604 | if (dev->power.runtime_auto) |
1605 | goto out; |
1606 | |
1607 | dev->power.runtime_auto = true; |
1608 | ret = rpm_drop_usage_count(dev); |
1609 | if (ret == 0) |
1610 | rpm_idle(dev, RPM_AUTO | RPM_ASYNC); |
1611 | else if (ret > 0) |
1612 | trace_rpm_usage(dev, RPM_AUTO | RPM_ASYNC); |
1613 | |
1614 | out: |
1615 | spin_unlock_irq(lock: &dev->power.lock); |
1616 | } |
1617 | EXPORT_SYMBOL_GPL(pm_runtime_allow); |
1618 | |
1619 | /** |
1620 | * pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device. |
1621 | * @dev: Device to handle. |
1622 | * |
1623 | * Set the power.no_callbacks flag, which tells the PM core that this |
1624 | * device is power-managed through its parent and has no runtime PM |
1625 | * callbacks of its own. The runtime sysfs attributes will be removed. |
1626 | */ |
1627 | void pm_runtime_no_callbacks(struct device *dev) |
1628 | { |
1629 | spin_lock_irq(lock: &dev->power.lock); |
1630 | dev->power.no_callbacks = 1; |
1631 | spin_unlock_irq(lock: &dev->power.lock); |
1632 | if (device_is_registered(dev)) |
1633 | rpm_sysfs_remove(dev); |
1634 | } |
1635 | EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks); |
1636 | |
1637 | /** |
1638 | * pm_runtime_irq_safe - Leave interrupts disabled during callbacks. |
1639 | * @dev: Device to handle |
1640 | * |
1641 | * Set the power.irq_safe flag, which tells the PM core that the |
1642 | * ->runtime_suspend() and ->runtime_resume() callbacks for this device should |
1643 | * always be invoked with the spinlock held and interrupts disabled. It also |
1644 | * causes the parent's usage counter to be permanently incremented, preventing |
1645 | * the parent from runtime suspending -- otherwise an irq-safe child might have |
1646 | * to wait for a non-irq-safe parent. |
1647 | */ |
1648 | void pm_runtime_irq_safe(struct device *dev) |
1649 | { |
1650 | if (dev->parent) |
1651 | pm_runtime_get_sync(dev: dev->parent); |
1652 | |
1653 | spin_lock_irq(lock: &dev->power.lock); |
1654 | dev->power.irq_safe = 1; |
1655 | spin_unlock_irq(lock: &dev->power.lock); |
1656 | } |
1657 | EXPORT_SYMBOL_GPL(pm_runtime_irq_safe); |
1658 | |
1659 | /** |
1660 | * update_autosuspend - Handle a change to a device's autosuspend settings. |
1661 | * @dev: Device to handle. |
1662 | * @old_delay: The former autosuspend_delay value. |
1663 | * @old_use: The former use_autosuspend value. |
1664 | * |
1665 | * Prevent runtime suspend if the new delay is negative and use_autosuspend is |
1666 | * set; otherwise allow it. Send an idle notification if suspends are allowed. |
1667 | * |
1668 | * This function must be called under dev->power.lock with interrupts disabled. |
1669 | */ |
1670 | static void update_autosuspend(struct device *dev, int old_delay, int old_use) |
1671 | { |
1672 | int delay = dev->power.autosuspend_delay; |
1673 | |
1674 | /* Should runtime suspend be prevented now? */ |
1675 | if (dev->power.use_autosuspend && delay < 0) { |
1676 | |
1677 | /* If it used to be allowed then prevent it. */ |
1678 | if (!old_use || old_delay >= 0) { |
1679 | atomic_inc(v: &dev->power.usage_count); |
1680 | rpm_resume(dev, rpmflags: 0); |
1681 | } else { |
1682 | trace_rpm_usage(dev, flags: 0); |
1683 | } |
1684 | } |
1685 | |
1686 | /* Runtime suspend should be allowed now. */ |
1687 | else { |
1688 | |
1689 | /* If it used to be prevented then allow it. */ |
1690 | if (old_use && old_delay < 0) |
1691 | atomic_dec(v: &dev->power.usage_count); |
1692 | |
1693 | /* Maybe we can autosuspend now. */ |
1694 | rpm_idle(dev, RPM_AUTO); |
1695 | } |
1696 | } |
1697 | |
1698 | /** |
1699 | * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value. |
1700 | * @dev: Device to handle. |
1701 | * @delay: Value of the new delay in milliseconds. |
1702 | * |
1703 | * Set the device's power.autosuspend_delay value. If it changes to negative |
1704 | * and the power.use_autosuspend flag is set, prevent runtime suspends. If it |
1705 | * changes the other way, allow runtime suspends. |
1706 | */ |
1707 | void pm_runtime_set_autosuspend_delay(struct device *dev, int delay) |
1708 | { |
1709 | int old_delay, old_use; |
1710 | |
1711 | spin_lock_irq(lock: &dev->power.lock); |
1712 | old_delay = dev->power.autosuspend_delay; |
1713 | old_use = dev->power.use_autosuspend; |
1714 | dev->power.autosuspend_delay = delay; |
1715 | update_autosuspend(dev, old_delay, old_use); |
1716 | spin_unlock_irq(lock: &dev->power.lock); |
1717 | } |
1718 | EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay); |
1719 | |
1720 | /** |
1721 | * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag. |
1722 | * @dev: Device to handle. |
1723 | * @use: New value for use_autosuspend. |
1724 | * |
1725 | * Set the device's power.use_autosuspend flag, and allow or prevent runtime |
1726 | * suspends as needed. |
1727 | */ |
1728 | void __pm_runtime_use_autosuspend(struct device *dev, bool use) |
1729 | { |
1730 | int old_delay, old_use; |
1731 | |
1732 | spin_lock_irq(lock: &dev->power.lock); |
1733 | old_delay = dev->power.autosuspend_delay; |
1734 | old_use = dev->power.use_autosuspend; |
1735 | dev->power.use_autosuspend = use; |
1736 | update_autosuspend(dev, old_delay, old_use); |
1737 | spin_unlock_irq(lock: &dev->power.lock); |
1738 | } |
1739 | EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend); |
1740 | |
1741 | /** |
1742 | * pm_runtime_init - Initialize runtime PM fields in given device object. |
1743 | * @dev: Device object to initialize. |
1744 | */ |
1745 | void pm_runtime_init(struct device *dev) |
1746 | { |
1747 | dev->power.runtime_status = RPM_SUSPENDED; |
1748 | dev->power.last_status = RPM_INVALID; |
1749 | dev->power.idle_notification = false; |
1750 | |
1751 | dev->power.disable_depth = 1; |
1752 | atomic_set(v: &dev->power.usage_count, i: 0); |
1753 | |
1754 | dev->power.runtime_error = 0; |
1755 | |
1756 | atomic_set(v: &dev->power.child_count, i: 0); |
1757 | pm_suspend_ignore_children(dev, enable: false); |
1758 | dev->power.runtime_auto = true; |
1759 | |
1760 | dev->power.request_pending = false; |
1761 | dev->power.request = RPM_REQ_NONE; |
1762 | dev->power.deferred_resume = false; |
1763 | dev->power.needs_force_resume = 0; |
1764 | INIT_WORK(&dev->power.work, pm_runtime_work); |
1765 | |
1766 | dev->power.timer_expires = 0; |
1767 | hrtimer_init(timer: &dev->power.suspend_timer, CLOCK_MONOTONIC, mode: HRTIMER_MODE_ABS); |
1768 | dev->power.suspend_timer.function = pm_suspend_timer_fn; |
1769 | |
1770 | init_waitqueue_head(&dev->power.wait_queue); |
1771 | } |
1772 | |
1773 | /** |
1774 | * pm_runtime_reinit - Re-initialize runtime PM fields in given device object. |
1775 | * @dev: Device object to re-initialize. |
1776 | */ |
1777 | void pm_runtime_reinit(struct device *dev) |
1778 | { |
1779 | if (!pm_runtime_enabled(dev)) { |
1780 | if (dev->power.runtime_status == RPM_ACTIVE) |
1781 | pm_runtime_set_suspended(dev); |
1782 | if (dev->power.irq_safe) { |
1783 | spin_lock_irq(lock: &dev->power.lock); |
1784 | dev->power.irq_safe = 0; |
1785 | spin_unlock_irq(lock: &dev->power.lock); |
1786 | if (dev->parent) |
1787 | pm_runtime_put(dev: dev->parent); |
1788 | } |
1789 | } |
1790 | } |
1791 | |
1792 | /** |
1793 | * pm_runtime_remove - Prepare for removing a device from device hierarchy. |
1794 | * @dev: Device object being removed from device hierarchy. |
1795 | */ |
1796 | void pm_runtime_remove(struct device *dev) |
1797 | { |
1798 | __pm_runtime_disable(dev, false); |
1799 | pm_runtime_reinit(dev); |
1800 | } |
1801 | |
1802 | /** |
1803 | * pm_runtime_get_suppliers - Resume and reference-count supplier devices. |
1804 | * @dev: Consumer device. |
1805 | */ |
1806 | void pm_runtime_get_suppliers(struct device *dev) |
1807 | { |
1808 | struct device_link *link; |
1809 | int idx; |
1810 | |
1811 | idx = device_links_read_lock(); |
1812 | |
1813 | list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, |
1814 | device_links_read_lock_held()) |
1815 | if (link->flags & DL_FLAG_PM_RUNTIME) { |
1816 | link->supplier_preactivated = true; |
1817 | pm_runtime_get_sync(dev: link->supplier); |
1818 | } |
1819 | |
1820 | device_links_read_unlock(idx); |
1821 | } |
1822 | |
1823 | /** |
1824 | * pm_runtime_put_suppliers - Drop references to supplier devices. |
1825 | * @dev: Consumer device. |
1826 | */ |
1827 | void pm_runtime_put_suppliers(struct device *dev) |
1828 | { |
1829 | struct device_link *link; |
1830 | int idx; |
1831 | |
1832 | idx = device_links_read_lock(); |
1833 | |
1834 | list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, |
1835 | device_links_read_lock_held()) |
1836 | if (link->supplier_preactivated) { |
1837 | link->supplier_preactivated = false; |
1838 | pm_runtime_put(dev: link->supplier); |
1839 | } |
1840 | |
1841 | device_links_read_unlock(idx); |
1842 | } |
1843 | |
1844 | void pm_runtime_new_link(struct device *dev) |
1845 | { |
1846 | spin_lock_irq(lock: &dev->power.lock); |
1847 | dev->power.links_count++; |
1848 | spin_unlock_irq(lock: &dev->power.lock); |
1849 | } |
1850 | |
1851 | static void pm_runtime_drop_link_count(struct device *dev) |
1852 | { |
1853 | spin_lock_irq(lock: &dev->power.lock); |
1854 | WARN_ON(dev->power.links_count == 0); |
1855 | dev->power.links_count--; |
1856 | spin_unlock_irq(lock: &dev->power.lock); |
1857 | } |
1858 | |
1859 | /** |
1860 | * pm_runtime_drop_link - Prepare for device link removal. |
1861 | * @link: Device link going away. |
1862 | * |
1863 | * Drop the link count of the consumer end of @link and decrement the supplier |
1864 | * device's runtime PM usage counter as many times as needed to drop all of the |
1865 | * PM runtime reference to it from the consumer. |
1866 | */ |
1867 | void pm_runtime_drop_link(struct device_link *link) |
1868 | { |
1869 | if (!(link->flags & DL_FLAG_PM_RUNTIME)) |
1870 | return; |
1871 | |
1872 | pm_runtime_drop_link_count(dev: link->consumer); |
1873 | pm_runtime_release_supplier(link); |
1874 | pm_request_idle(dev: link->supplier); |
1875 | } |
1876 | |
1877 | static bool pm_runtime_need_not_resume(struct device *dev) |
1878 | { |
1879 | return atomic_read(v: &dev->power.usage_count) <= 1 && |
1880 | (atomic_read(v: &dev->power.child_count) == 0 || |
1881 | dev->power.ignore_children); |
1882 | } |
1883 | |
1884 | /** |
1885 | * pm_runtime_force_suspend - Force a device into suspend state if needed. |
1886 | * @dev: Device to suspend. |
1887 | * |
1888 | * Disable runtime PM so we safely can check the device's runtime PM status and |
1889 | * if it is active, invoke its ->runtime_suspend callback to suspend it and |
1890 | * change its runtime PM status field to RPM_SUSPENDED. Also, if the device's |
1891 | * usage and children counters don't indicate that the device was in use before |
1892 | * the system-wide transition under way, decrement its parent's children counter |
1893 | * (if there is a parent). Keep runtime PM disabled to preserve the state |
1894 | * unless we encounter errors. |
1895 | * |
1896 | * Typically this function may be invoked from a system suspend callback to make |
1897 | * sure the device is put into low power state and it should only be used during |
1898 | * system-wide PM transitions to sleep states. It assumes that the analogous |
1899 | * pm_runtime_force_resume() will be used to resume the device. |
1900 | * |
1901 | * Do not use with DPM_FLAG_SMART_SUSPEND as this can lead to an inconsistent |
1902 | * state where this function has called the ->runtime_suspend callback but the |
1903 | * PM core marks the driver as runtime active. |
1904 | */ |
1905 | int pm_runtime_force_suspend(struct device *dev) |
1906 | { |
1907 | int (*callback)(struct device *); |
1908 | int ret; |
1909 | |
1910 | pm_runtime_disable(dev); |
1911 | if (pm_runtime_status_suspended(dev)) |
1912 | return 0; |
1913 | |
1914 | callback = RPM_GET_CALLBACK(dev, runtime_suspend); |
1915 | |
1916 | dev_pm_enable_wake_irq_check(dev, can_change_status: true); |
1917 | ret = callback ? callback(dev) : 0; |
1918 | if (ret) |
1919 | goto err; |
1920 | |
1921 | dev_pm_enable_wake_irq_complete(dev); |
1922 | |
1923 | /* |
1924 | * If the device can stay in suspend after the system-wide transition |
1925 | * to the working state that will follow, drop the children counter of |
1926 | * its parent, but set its status to RPM_SUSPENDED anyway in case this |
1927 | * function will be called again for it in the meantime. |
1928 | */ |
1929 | if (pm_runtime_need_not_resume(dev)) { |
1930 | pm_runtime_set_suspended(dev); |
1931 | } else { |
1932 | __update_runtime_status(dev, status: RPM_SUSPENDED); |
1933 | dev->power.needs_force_resume = 1; |
1934 | } |
1935 | |
1936 | return 0; |
1937 | |
1938 | err: |
1939 | dev_pm_disable_wake_irq_check(dev, cond_disable: true); |
1940 | pm_runtime_enable(dev); |
1941 | return ret; |
1942 | } |
1943 | EXPORT_SYMBOL_GPL(pm_runtime_force_suspend); |
1944 | |
1945 | /** |
1946 | * pm_runtime_force_resume - Force a device into resume state if needed. |
1947 | * @dev: Device to resume. |
1948 | * |
1949 | * Prior invoking this function we expect the user to have brought the device |
1950 | * into low power state by a call to pm_runtime_force_suspend(). Here we reverse |
1951 | * those actions and bring the device into full power, if it is expected to be |
1952 | * used on system resume. In the other case, we defer the resume to be managed |
1953 | * via runtime PM. |
1954 | * |
1955 | * Typically this function may be invoked from a system resume callback. |
1956 | */ |
1957 | int pm_runtime_force_resume(struct device *dev) |
1958 | { |
1959 | int (*callback)(struct device *); |
1960 | int ret = 0; |
1961 | |
1962 | if (!pm_runtime_status_suspended(dev) || !dev->power.needs_force_resume) |
1963 | goto out; |
1964 | |
1965 | /* |
1966 | * The value of the parent's children counter is correct already, so |
1967 | * just update the status of the device. |
1968 | */ |
1969 | __update_runtime_status(dev, status: RPM_ACTIVE); |
1970 | |
1971 | callback = RPM_GET_CALLBACK(dev, runtime_resume); |
1972 | |
1973 | dev_pm_disable_wake_irq_check(dev, cond_disable: false); |
1974 | ret = callback ? callback(dev) : 0; |
1975 | if (ret) { |
1976 | pm_runtime_set_suspended(dev); |
1977 | dev_pm_enable_wake_irq_check(dev, can_change_status: false); |
1978 | goto out; |
1979 | } |
1980 | |
1981 | pm_runtime_mark_last_busy(dev); |
1982 | out: |
1983 | dev->power.needs_force_resume = 0; |
1984 | pm_runtime_enable(dev); |
1985 | return ret; |
1986 | } |
1987 | EXPORT_SYMBOL_GPL(pm_runtime_force_resume); |
1988 | |