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