xref: /openbmc/linux/drivers/base/power/domain.c (revision 63e2bd10)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * drivers/base/power/domain.c - Common code related to device power domains.
4  *
5  * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
6  */
7 #define pr_fmt(fmt) "PM: " fmt
8 
9 #include <linux/delay.h>
10 #include <linux/kernel.h>
11 #include <linux/io.h>
12 #include <linux/platform_device.h>
13 #include <linux/pm_opp.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/pm_domain.h>
16 #include <linux/pm_qos.h>
17 #include <linux/pm_clock.h>
18 #include <linux/slab.h>
19 #include <linux/err.h>
20 #include <linux/sched.h>
21 #include <linux/suspend.h>
22 #include <linux/export.h>
23 #include <linux/cpu.h>
24 #include <linux/debugfs.h>
25 
26 #include "power.h"
27 
28 #define GENPD_RETRY_MAX_MS	250		/* Approximate */
29 
30 #define GENPD_DEV_CALLBACK(genpd, type, callback, dev)		\
31 ({								\
32 	type (*__routine)(struct device *__d); 			\
33 	type __ret = (type)0;					\
34 								\
35 	__routine = genpd->dev_ops.callback; 			\
36 	if (__routine) {					\
37 		__ret = __routine(dev); 			\
38 	}							\
39 	__ret;							\
40 })
41 
42 static LIST_HEAD(gpd_list);
43 static DEFINE_MUTEX(gpd_list_lock);
44 
45 struct genpd_lock_ops {
46 	void (*lock)(struct generic_pm_domain *genpd);
47 	void (*lock_nested)(struct generic_pm_domain *genpd, int depth);
48 	int (*lock_interruptible)(struct generic_pm_domain *genpd);
49 	void (*unlock)(struct generic_pm_domain *genpd);
50 };
51 
52 static void genpd_lock_mtx(struct generic_pm_domain *genpd)
53 {
54 	mutex_lock(&genpd->mlock);
55 }
56 
57 static void genpd_lock_nested_mtx(struct generic_pm_domain *genpd,
58 					int depth)
59 {
60 	mutex_lock_nested(&genpd->mlock, depth);
61 }
62 
63 static int genpd_lock_interruptible_mtx(struct generic_pm_domain *genpd)
64 {
65 	return mutex_lock_interruptible(&genpd->mlock);
66 }
67 
68 static void genpd_unlock_mtx(struct generic_pm_domain *genpd)
69 {
70 	return mutex_unlock(&genpd->mlock);
71 }
72 
73 static const struct genpd_lock_ops genpd_mtx_ops = {
74 	.lock = genpd_lock_mtx,
75 	.lock_nested = genpd_lock_nested_mtx,
76 	.lock_interruptible = genpd_lock_interruptible_mtx,
77 	.unlock = genpd_unlock_mtx,
78 };
79 
80 static void genpd_lock_spin(struct generic_pm_domain *genpd)
81 	__acquires(&genpd->slock)
82 {
83 	unsigned long flags;
84 
85 	spin_lock_irqsave(&genpd->slock, flags);
86 	genpd->lock_flags = flags;
87 }
88 
89 static void genpd_lock_nested_spin(struct generic_pm_domain *genpd,
90 					int depth)
91 	__acquires(&genpd->slock)
92 {
93 	unsigned long flags;
94 
95 	spin_lock_irqsave_nested(&genpd->slock, flags, depth);
96 	genpd->lock_flags = flags;
97 }
98 
99 static int genpd_lock_interruptible_spin(struct generic_pm_domain *genpd)
100 	__acquires(&genpd->slock)
101 {
102 	unsigned long flags;
103 
104 	spin_lock_irqsave(&genpd->slock, flags);
105 	genpd->lock_flags = flags;
106 	return 0;
107 }
108 
109 static void genpd_unlock_spin(struct generic_pm_domain *genpd)
110 	__releases(&genpd->slock)
111 {
112 	spin_unlock_irqrestore(&genpd->slock, genpd->lock_flags);
113 }
114 
115 static const struct genpd_lock_ops genpd_spin_ops = {
116 	.lock = genpd_lock_spin,
117 	.lock_nested = genpd_lock_nested_spin,
118 	.lock_interruptible = genpd_lock_interruptible_spin,
119 	.unlock = genpd_unlock_spin,
120 };
121 
122 #define genpd_lock(p)			p->lock_ops->lock(p)
123 #define genpd_lock_nested(p, d)		p->lock_ops->lock_nested(p, d)
124 #define genpd_lock_interruptible(p)	p->lock_ops->lock_interruptible(p)
125 #define genpd_unlock(p)			p->lock_ops->unlock(p)
126 
127 #define genpd_status_on(genpd)		(genpd->status == GENPD_STATE_ON)
128 #define genpd_is_irq_safe(genpd)	(genpd->flags & GENPD_FLAG_IRQ_SAFE)
129 #define genpd_is_always_on(genpd)	(genpd->flags & GENPD_FLAG_ALWAYS_ON)
130 #define genpd_is_active_wakeup(genpd)	(genpd->flags & GENPD_FLAG_ACTIVE_WAKEUP)
131 #define genpd_is_cpu_domain(genpd)	(genpd->flags & GENPD_FLAG_CPU_DOMAIN)
132 #define genpd_is_rpm_always_on(genpd)	(genpd->flags & GENPD_FLAG_RPM_ALWAYS_ON)
133 
134 static inline bool irq_safe_dev_in_sleep_domain(struct device *dev,
135 		const struct generic_pm_domain *genpd)
136 {
137 	bool ret;
138 
139 	ret = pm_runtime_is_irq_safe(dev) && !genpd_is_irq_safe(genpd);
140 
141 	/*
142 	 * Warn once if an IRQ safe device is attached to a domain, which
143 	 * callbacks are allowed to sleep. This indicates a suboptimal
144 	 * configuration for PM, but it doesn't matter for an always on domain.
145 	 */
146 	if (genpd_is_always_on(genpd) || genpd_is_rpm_always_on(genpd))
147 		return ret;
148 
149 	if (ret)
150 		dev_warn_once(dev, "PM domain %s will not be powered off\n",
151 				genpd->name);
152 
153 	return ret;
154 }
155 
156 static int genpd_runtime_suspend(struct device *dev);
157 
158 /*
159  * Get the generic PM domain for a particular struct device.
160  * This validates the struct device pointer, the PM domain pointer,
161  * and checks that the PM domain pointer is a real generic PM domain.
162  * Any failure results in NULL being returned.
163  */
164 static struct generic_pm_domain *dev_to_genpd_safe(struct device *dev)
165 {
166 	if (IS_ERR_OR_NULL(dev) || IS_ERR_OR_NULL(dev->pm_domain))
167 		return NULL;
168 
169 	/* A genpd's always have its ->runtime_suspend() callback assigned. */
170 	if (dev->pm_domain->ops.runtime_suspend == genpd_runtime_suspend)
171 		return pd_to_genpd(dev->pm_domain);
172 
173 	return NULL;
174 }
175 
176 /*
177  * This should only be used where we are certain that the pm_domain
178  * attached to the device is a genpd domain.
179  */
180 static struct generic_pm_domain *dev_to_genpd(struct device *dev)
181 {
182 	if (IS_ERR_OR_NULL(dev->pm_domain))
183 		return ERR_PTR(-EINVAL);
184 
185 	return pd_to_genpd(dev->pm_domain);
186 }
187 
188 static int genpd_stop_dev(const struct generic_pm_domain *genpd,
189 			  struct device *dev)
190 {
191 	return GENPD_DEV_CALLBACK(genpd, int, stop, dev);
192 }
193 
194 static int genpd_start_dev(const struct generic_pm_domain *genpd,
195 			   struct device *dev)
196 {
197 	return GENPD_DEV_CALLBACK(genpd, int, start, dev);
198 }
199 
200 static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd)
201 {
202 	bool ret = false;
203 
204 	if (!WARN_ON(atomic_read(&genpd->sd_count) == 0))
205 		ret = !!atomic_dec_and_test(&genpd->sd_count);
206 
207 	return ret;
208 }
209 
210 static void genpd_sd_counter_inc(struct generic_pm_domain *genpd)
211 {
212 	atomic_inc(&genpd->sd_count);
213 	smp_mb__after_atomic();
214 }
215 
216 #ifdef CONFIG_DEBUG_FS
217 static struct dentry *genpd_debugfs_dir;
218 
219 static void genpd_debug_add(struct generic_pm_domain *genpd);
220 
221 static void genpd_debug_remove(struct generic_pm_domain *genpd)
222 {
223 	if (!genpd_debugfs_dir)
224 		return;
225 
226 	debugfs_lookup_and_remove(genpd->name, genpd_debugfs_dir);
227 }
228 
229 static void genpd_update_accounting(struct generic_pm_domain *genpd)
230 {
231 	u64 delta, now;
232 
233 	now = ktime_get_mono_fast_ns();
234 	if (now <= genpd->accounting_time)
235 		return;
236 
237 	delta = now - genpd->accounting_time;
238 
239 	/*
240 	 * If genpd->status is active, it means we are just
241 	 * out of off and so update the idle time and vice
242 	 * versa.
243 	 */
244 	if (genpd->status == GENPD_STATE_ON)
245 		genpd->states[genpd->state_idx].idle_time += delta;
246 	else
247 		genpd->on_time += delta;
248 
249 	genpd->accounting_time = now;
250 }
251 #else
252 static inline void genpd_debug_add(struct generic_pm_domain *genpd) {}
253 static inline void genpd_debug_remove(struct generic_pm_domain *genpd) {}
254 static inline void genpd_update_accounting(struct generic_pm_domain *genpd) {}
255 #endif
256 
257 static int _genpd_reeval_performance_state(struct generic_pm_domain *genpd,
258 					   unsigned int state)
259 {
260 	struct generic_pm_domain_data *pd_data;
261 	struct pm_domain_data *pdd;
262 	struct gpd_link *link;
263 
264 	/* New requested state is same as Max requested state */
265 	if (state == genpd->performance_state)
266 		return state;
267 
268 	/* New requested state is higher than Max requested state */
269 	if (state > genpd->performance_state)
270 		return state;
271 
272 	/* Traverse all devices within the domain */
273 	list_for_each_entry(pdd, &genpd->dev_list, list_node) {
274 		pd_data = to_gpd_data(pdd);
275 
276 		if (pd_data->performance_state > state)
277 			state = pd_data->performance_state;
278 	}
279 
280 	/*
281 	 * Traverse all sub-domains within the domain. This can be
282 	 * done without any additional locking as the link->performance_state
283 	 * field is protected by the parent genpd->lock, which is already taken.
284 	 *
285 	 * Also note that link->performance_state (subdomain's performance state
286 	 * requirement to parent domain) is different from
287 	 * link->child->performance_state (current performance state requirement
288 	 * of the devices/sub-domains of the subdomain) and so can have a
289 	 * different value.
290 	 *
291 	 * Note that we also take vote from powered-off sub-domains into account
292 	 * as the same is done for devices right now.
293 	 */
294 	list_for_each_entry(link, &genpd->parent_links, parent_node) {
295 		if (link->performance_state > state)
296 			state = link->performance_state;
297 	}
298 
299 	return state;
300 }
301 
302 static int genpd_xlate_performance_state(struct generic_pm_domain *genpd,
303 					 struct generic_pm_domain *parent,
304 					 unsigned int pstate)
305 {
306 	if (!parent->set_performance_state)
307 		return pstate;
308 
309 	return dev_pm_opp_xlate_performance_state(genpd->opp_table,
310 						  parent->opp_table,
311 						  pstate);
312 }
313 
314 static int _genpd_set_performance_state(struct generic_pm_domain *genpd,
315 					unsigned int state, int depth)
316 {
317 	struct generic_pm_domain *parent;
318 	struct gpd_link *link;
319 	int parent_state, ret;
320 
321 	if (state == genpd->performance_state)
322 		return 0;
323 
324 	/* Propagate to parents of genpd */
325 	list_for_each_entry(link, &genpd->child_links, child_node) {
326 		parent = link->parent;
327 
328 		/* Find parent's performance state */
329 		ret = genpd_xlate_performance_state(genpd, parent, state);
330 		if (unlikely(ret < 0))
331 			goto err;
332 
333 		parent_state = ret;
334 
335 		genpd_lock_nested(parent, depth + 1);
336 
337 		link->prev_performance_state = link->performance_state;
338 		link->performance_state = parent_state;
339 		parent_state = _genpd_reeval_performance_state(parent,
340 						parent_state);
341 		ret = _genpd_set_performance_state(parent, parent_state, depth + 1);
342 		if (ret)
343 			link->performance_state = link->prev_performance_state;
344 
345 		genpd_unlock(parent);
346 
347 		if (ret)
348 			goto err;
349 	}
350 
351 	if (genpd->set_performance_state) {
352 		ret = genpd->set_performance_state(genpd, state);
353 		if (ret)
354 			goto err;
355 	}
356 
357 	genpd->performance_state = state;
358 	return 0;
359 
360 err:
361 	/* Encountered an error, lets rollback */
362 	list_for_each_entry_continue_reverse(link, &genpd->child_links,
363 					     child_node) {
364 		parent = link->parent;
365 
366 		genpd_lock_nested(parent, depth + 1);
367 
368 		parent_state = link->prev_performance_state;
369 		link->performance_state = parent_state;
370 
371 		parent_state = _genpd_reeval_performance_state(parent,
372 						parent_state);
373 		if (_genpd_set_performance_state(parent, parent_state, depth + 1)) {
374 			pr_err("%s: Failed to roll back to %d performance state\n",
375 			       parent->name, parent_state);
376 		}
377 
378 		genpd_unlock(parent);
379 	}
380 
381 	return ret;
382 }
383 
384 static int genpd_set_performance_state(struct device *dev, unsigned int state)
385 {
386 	struct generic_pm_domain *genpd = dev_to_genpd(dev);
387 	struct generic_pm_domain_data *gpd_data = dev_gpd_data(dev);
388 	unsigned int prev_state;
389 	int ret;
390 
391 	prev_state = gpd_data->performance_state;
392 	if (prev_state == state)
393 		return 0;
394 
395 	gpd_data->performance_state = state;
396 	state = _genpd_reeval_performance_state(genpd, state);
397 
398 	ret = _genpd_set_performance_state(genpd, state, 0);
399 	if (ret)
400 		gpd_data->performance_state = prev_state;
401 
402 	return ret;
403 }
404 
405 static int genpd_drop_performance_state(struct device *dev)
406 {
407 	unsigned int prev_state = dev_gpd_data(dev)->performance_state;
408 
409 	if (!genpd_set_performance_state(dev, 0))
410 		return prev_state;
411 
412 	return 0;
413 }
414 
415 static void genpd_restore_performance_state(struct device *dev,
416 					    unsigned int state)
417 {
418 	if (state)
419 		genpd_set_performance_state(dev, state);
420 }
421 
422 /**
423  * dev_pm_genpd_set_performance_state- Set performance state of device's power
424  * domain.
425  *
426  * @dev: Device for which the performance-state needs to be set.
427  * @state: Target performance state of the device. This can be set as 0 when the
428  *	   device doesn't have any performance state constraints left (And so
429  *	   the device wouldn't participate anymore to find the target
430  *	   performance state of the genpd).
431  *
432  * It is assumed that the users guarantee that the genpd wouldn't be detached
433  * while this routine is getting called.
434  *
435  * Returns 0 on success and negative error values on failures.
436  */
437 int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state)
438 {
439 	struct generic_pm_domain *genpd;
440 	int ret = 0;
441 
442 	genpd = dev_to_genpd_safe(dev);
443 	if (!genpd)
444 		return -ENODEV;
445 
446 	if (WARN_ON(!dev->power.subsys_data ||
447 		     !dev->power.subsys_data->domain_data))
448 		return -EINVAL;
449 
450 	genpd_lock(genpd);
451 	if (pm_runtime_suspended(dev)) {
452 		dev_gpd_data(dev)->rpm_pstate = state;
453 	} else {
454 		ret = genpd_set_performance_state(dev, state);
455 		if (!ret)
456 			dev_gpd_data(dev)->rpm_pstate = 0;
457 	}
458 	genpd_unlock(genpd);
459 
460 	return ret;
461 }
462 EXPORT_SYMBOL_GPL(dev_pm_genpd_set_performance_state);
463 
464 /**
465  * dev_pm_genpd_set_next_wakeup - Notify PM framework of an impending wakeup.
466  *
467  * @dev: Device to handle
468  * @next: impending interrupt/wakeup for the device
469  *
470  *
471  * Allow devices to inform of the next wakeup. It's assumed that the users
472  * guarantee that the genpd wouldn't be detached while this routine is getting
473  * called. Additionally, it's also assumed that @dev isn't runtime suspended
474  * (RPM_SUSPENDED)."
475  * Although devices are expected to update the next_wakeup after the end of
476  * their usecase as well, it is possible the devices themselves may not know
477  * about that, so stale @next will be ignored when powering off the domain.
478  */
479 void dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next)
480 {
481 	struct generic_pm_domain *genpd;
482 	struct gpd_timing_data *td;
483 
484 	genpd = dev_to_genpd_safe(dev);
485 	if (!genpd)
486 		return;
487 
488 	td = to_gpd_data(dev->power.subsys_data->domain_data)->td;
489 	if (td)
490 		td->next_wakeup = next;
491 }
492 EXPORT_SYMBOL_GPL(dev_pm_genpd_set_next_wakeup);
493 
494 /**
495  * dev_pm_genpd_get_next_hrtimer - Return the next_hrtimer for the genpd
496  * @dev: A device that is attached to the genpd.
497  *
498  * This routine should typically be called for a device, at the point of when a
499  * GENPD_NOTIFY_PRE_OFF notification has been sent for it.
500  *
501  * Returns the aggregated value of the genpd's next hrtimer or KTIME_MAX if no
502  * valid value have been set.
503  */
504 ktime_t dev_pm_genpd_get_next_hrtimer(struct device *dev)
505 {
506 	struct generic_pm_domain *genpd;
507 
508 	genpd = dev_to_genpd_safe(dev);
509 	if (!genpd)
510 		return KTIME_MAX;
511 
512 	if (genpd->gd)
513 		return genpd->gd->next_hrtimer;
514 
515 	return KTIME_MAX;
516 }
517 EXPORT_SYMBOL_GPL(dev_pm_genpd_get_next_hrtimer);
518 
519 /*
520  * dev_pm_genpd_synced_poweroff - Next power off should be synchronous
521  *
522  * @dev: A device that is attached to the genpd.
523  *
524  * Allows a consumer of the genpd to notify the provider that the next power off
525  * should be synchronous.
526  *
527  * It is assumed that the users guarantee that the genpd wouldn't be detached
528  * while this routine is getting called.
529  */
530 void dev_pm_genpd_synced_poweroff(struct device *dev)
531 {
532 	struct generic_pm_domain *genpd;
533 
534 	genpd = dev_to_genpd_safe(dev);
535 	if (!genpd)
536 		return;
537 
538 	genpd_lock(genpd);
539 	genpd->synced_poweroff = true;
540 	genpd_unlock(genpd);
541 }
542 EXPORT_SYMBOL_GPL(dev_pm_genpd_synced_poweroff);
543 
544 static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed)
545 {
546 	unsigned int state_idx = genpd->state_idx;
547 	ktime_t time_start;
548 	s64 elapsed_ns;
549 	int ret;
550 
551 	/* Notify consumers that we are about to power on. */
552 	ret = raw_notifier_call_chain_robust(&genpd->power_notifiers,
553 					     GENPD_NOTIFY_PRE_ON,
554 					     GENPD_NOTIFY_OFF, NULL);
555 	ret = notifier_to_errno(ret);
556 	if (ret)
557 		return ret;
558 
559 	if (!genpd->power_on)
560 		goto out;
561 
562 	timed = timed && genpd->gd && !genpd->states[state_idx].fwnode;
563 	if (!timed) {
564 		ret = genpd->power_on(genpd);
565 		if (ret)
566 			goto err;
567 
568 		goto out;
569 	}
570 
571 	time_start = ktime_get();
572 	ret = genpd->power_on(genpd);
573 	if (ret)
574 		goto err;
575 
576 	elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
577 	if (elapsed_ns <= genpd->states[state_idx].power_on_latency_ns)
578 		goto out;
579 
580 	genpd->states[state_idx].power_on_latency_ns = elapsed_ns;
581 	genpd->gd->max_off_time_changed = true;
582 	pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
583 		 genpd->name, "on", elapsed_ns);
584 
585 out:
586 	raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_ON, NULL);
587 	genpd->synced_poweroff = false;
588 	return 0;
589 err:
590 	raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_OFF,
591 				NULL);
592 	return ret;
593 }
594 
595 static int _genpd_power_off(struct generic_pm_domain *genpd, bool timed)
596 {
597 	unsigned int state_idx = genpd->state_idx;
598 	ktime_t time_start;
599 	s64 elapsed_ns;
600 	int ret;
601 
602 	/* Notify consumers that we are about to power off. */
603 	ret = raw_notifier_call_chain_robust(&genpd->power_notifiers,
604 					     GENPD_NOTIFY_PRE_OFF,
605 					     GENPD_NOTIFY_ON, NULL);
606 	ret = notifier_to_errno(ret);
607 	if (ret)
608 		return ret;
609 
610 	if (!genpd->power_off)
611 		goto out;
612 
613 	timed = timed && genpd->gd && !genpd->states[state_idx].fwnode;
614 	if (!timed) {
615 		ret = genpd->power_off(genpd);
616 		if (ret)
617 			goto busy;
618 
619 		goto out;
620 	}
621 
622 	time_start = ktime_get();
623 	ret = genpd->power_off(genpd);
624 	if (ret)
625 		goto busy;
626 
627 	elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
628 	if (elapsed_ns <= genpd->states[state_idx].power_off_latency_ns)
629 		goto out;
630 
631 	genpd->states[state_idx].power_off_latency_ns = elapsed_ns;
632 	genpd->gd->max_off_time_changed = true;
633 	pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
634 		 genpd->name, "off", elapsed_ns);
635 
636 out:
637 	raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_OFF,
638 				NULL);
639 	return 0;
640 busy:
641 	raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_ON, NULL);
642 	return ret;
643 }
644 
645 /**
646  * genpd_queue_power_off_work - Queue up the execution of genpd_power_off().
647  * @genpd: PM domain to power off.
648  *
649  * Queue up the execution of genpd_power_off() unless it's already been done
650  * before.
651  */
652 static void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
653 {
654 	queue_work(pm_wq, &genpd->power_off_work);
655 }
656 
657 /**
658  * genpd_power_off - Remove power from a given PM domain.
659  * @genpd: PM domain to power down.
660  * @one_dev_on: If invoked from genpd's ->runtime_suspend|resume() callback, the
661  * RPM status of the releated device is in an intermediate state, not yet turned
662  * into RPM_SUSPENDED. This means genpd_power_off() must allow one device to not
663  * be RPM_SUSPENDED, while it tries to power off the PM domain.
664  * @depth: nesting count for lockdep.
665  *
666  * If all of the @genpd's devices have been suspended and all of its subdomains
667  * have been powered down, remove power from @genpd.
668  */
669 static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
670 			   unsigned int depth)
671 {
672 	struct pm_domain_data *pdd;
673 	struct gpd_link *link;
674 	unsigned int not_suspended = 0;
675 	int ret;
676 
677 	/*
678 	 * Do not try to power off the domain in the following situations:
679 	 * (1) The domain is already in the "power off" state.
680 	 * (2) System suspend is in progress.
681 	 */
682 	if (!genpd_status_on(genpd) || genpd->prepared_count > 0)
683 		return 0;
684 
685 	/*
686 	 * Abort power off for the PM domain in the following situations:
687 	 * (1) The domain is configured as always on.
688 	 * (2) When the domain has a subdomain being powered on.
689 	 */
690 	if (genpd_is_always_on(genpd) ||
691 			genpd_is_rpm_always_on(genpd) ||
692 			atomic_read(&genpd->sd_count) > 0)
693 		return -EBUSY;
694 
695 	/*
696 	 * The children must be in their deepest (powered-off) states to allow
697 	 * the parent to be powered off. Note that, there's no need for
698 	 * additional locking, as powering on a child, requires the parent's
699 	 * lock to be acquired first.
700 	 */
701 	list_for_each_entry(link, &genpd->parent_links, parent_node) {
702 		struct generic_pm_domain *child = link->child;
703 		if (child->state_idx < child->state_count - 1)
704 			return -EBUSY;
705 	}
706 
707 	list_for_each_entry(pdd, &genpd->dev_list, list_node) {
708 		/*
709 		 * Do not allow PM domain to be powered off, when an IRQ safe
710 		 * device is part of a non-IRQ safe domain.
711 		 */
712 		if (!pm_runtime_suspended(pdd->dev) ||
713 			irq_safe_dev_in_sleep_domain(pdd->dev, genpd))
714 			not_suspended++;
715 	}
716 
717 	if (not_suspended > 1 || (not_suspended == 1 && !one_dev_on))
718 		return -EBUSY;
719 
720 	if (genpd->gov && genpd->gov->power_down_ok) {
721 		if (!genpd->gov->power_down_ok(&genpd->domain))
722 			return -EAGAIN;
723 	}
724 
725 	/* Default to shallowest state. */
726 	if (!genpd->gov)
727 		genpd->state_idx = 0;
728 
729 	/* Don't power off, if a child domain is waiting to power on. */
730 	if (atomic_read(&genpd->sd_count) > 0)
731 		return -EBUSY;
732 
733 	ret = _genpd_power_off(genpd, true);
734 	if (ret) {
735 		genpd->states[genpd->state_idx].rejected++;
736 		return ret;
737 	}
738 
739 	genpd->status = GENPD_STATE_OFF;
740 	genpd_update_accounting(genpd);
741 	genpd->states[genpd->state_idx].usage++;
742 
743 	list_for_each_entry(link, &genpd->child_links, child_node) {
744 		genpd_sd_counter_dec(link->parent);
745 		genpd_lock_nested(link->parent, depth + 1);
746 		genpd_power_off(link->parent, false, depth + 1);
747 		genpd_unlock(link->parent);
748 	}
749 
750 	return 0;
751 }
752 
753 /**
754  * genpd_power_on - Restore power to a given PM domain and its parents.
755  * @genpd: PM domain to power up.
756  * @depth: nesting count for lockdep.
757  *
758  * Restore power to @genpd and all of its parents so that it is possible to
759  * resume a device belonging to it.
760  */
761 static int genpd_power_on(struct generic_pm_domain *genpd, unsigned int depth)
762 {
763 	struct gpd_link *link;
764 	int ret = 0;
765 
766 	if (genpd_status_on(genpd))
767 		return 0;
768 
769 	/*
770 	 * The list is guaranteed not to change while the loop below is being
771 	 * executed, unless one of the parents' .power_on() callbacks fiddles
772 	 * with it.
773 	 */
774 	list_for_each_entry(link, &genpd->child_links, child_node) {
775 		struct generic_pm_domain *parent = link->parent;
776 
777 		genpd_sd_counter_inc(parent);
778 
779 		genpd_lock_nested(parent, depth + 1);
780 		ret = genpd_power_on(parent, depth + 1);
781 		genpd_unlock(parent);
782 
783 		if (ret) {
784 			genpd_sd_counter_dec(parent);
785 			goto err;
786 		}
787 	}
788 
789 	ret = _genpd_power_on(genpd, true);
790 	if (ret)
791 		goto err;
792 
793 	genpd->status = GENPD_STATE_ON;
794 	genpd_update_accounting(genpd);
795 
796 	return 0;
797 
798  err:
799 	list_for_each_entry_continue_reverse(link,
800 					&genpd->child_links,
801 					child_node) {
802 		genpd_sd_counter_dec(link->parent);
803 		genpd_lock_nested(link->parent, depth + 1);
804 		genpd_power_off(link->parent, false, depth + 1);
805 		genpd_unlock(link->parent);
806 	}
807 
808 	return ret;
809 }
810 
811 static int genpd_dev_pm_start(struct device *dev)
812 {
813 	struct generic_pm_domain *genpd = dev_to_genpd(dev);
814 
815 	return genpd_start_dev(genpd, dev);
816 }
817 
818 static int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
819 				     unsigned long val, void *ptr)
820 {
821 	struct generic_pm_domain_data *gpd_data;
822 	struct device *dev;
823 
824 	gpd_data = container_of(nb, struct generic_pm_domain_data, nb);
825 	dev = gpd_data->base.dev;
826 
827 	for (;;) {
828 		struct generic_pm_domain *genpd = ERR_PTR(-ENODATA);
829 		struct pm_domain_data *pdd;
830 		struct gpd_timing_data *td;
831 
832 		spin_lock_irq(&dev->power.lock);
833 
834 		pdd = dev->power.subsys_data ?
835 				dev->power.subsys_data->domain_data : NULL;
836 		if (pdd) {
837 			td = to_gpd_data(pdd)->td;
838 			if (td) {
839 				td->constraint_changed = true;
840 				genpd = dev_to_genpd(dev);
841 			}
842 		}
843 
844 		spin_unlock_irq(&dev->power.lock);
845 
846 		if (!IS_ERR(genpd)) {
847 			genpd_lock(genpd);
848 			genpd->gd->max_off_time_changed = true;
849 			genpd_unlock(genpd);
850 		}
851 
852 		dev = dev->parent;
853 		if (!dev || dev->power.ignore_children)
854 			break;
855 	}
856 
857 	return NOTIFY_DONE;
858 }
859 
860 /**
861  * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0.
862  * @work: Work structure used for scheduling the execution of this function.
863  */
864 static void genpd_power_off_work_fn(struct work_struct *work)
865 {
866 	struct generic_pm_domain *genpd;
867 
868 	genpd = container_of(work, struct generic_pm_domain, power_off_work);
869 
870 	genpd_lock(genpd);
871 	genpd_power_off(genpd, false, 0);
872 	genpd_unlock(genpd);
873 }
874 
875 /**
876  * __genpd_runtime_suspend - walk the hierarchy of ->runtime_suspend() callbacks
877  * @dev: Device to handle.
878  */
879 static int __genpd_runtime_suspend(struct device *dev)
880 {
881 	int (*cb)(struct device *__dev);
882 
883 	if (dev->type && dev->type->pm)
884 		cb = dev->type->pm->runtime_suspend;
885 	else if (dev->class && dev->class->pm)
886 		cb = dev->class->pm->runtime_suspend;
887 	else if (dev->bus && dev->bus->pm)
888 		cb = dev->bus->pm->runtime_suspend;
889 	else
890 		cb = NULL;
891 
892 	if (!cb && dev->driver && dev->driver->pm)
893 		cb = dev->driver->pm->runtime_suspend;
894 
895 	return cb ? cb(dev) : 0;
896 }
897 
898 /**
899  * __genpd_runtime_resume - walk the hierarchy of ->runtime_resume() callbacks
900  * @dev: Device to handle.
901  */
902 static int __genpd_runtime_resume(struct device *dev)
903 {
904 	int (*cb)(struct device *__dev);
905 
906 	if (dev->type && dev->type->pm)
907 		cb = dev->type->pm->runtime_resume;
908 	else if (dev->class && dev->class->pm)
909 		cb = dev->class->pm->runtime_resume;
910 	else if (dev->bus && dev->bus->pm)
911 		cb = dev->bus->pm->runtime_resume;
912 	else
913 		cb = NULL;
914 
915 	if (!cb && dev->driver && dev->driver->pm)
916 		cb = dev->driver->pm->runtime_resume;
917 
918 	return cb ? cb(dev) : 0;
919 }
920 
921 /**
922  * genpd_runtime_suspend - Suspend a device belonging to I/O PM domain.
923  * @dev: Device to suspend.
924  *
925  * Carry out a runtime suspend of a device under the assumption that its
926  * pm_domain field points to the domain member of an object of type
927  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
928  */
929 static int genpd_runtime_suspend(struct device *dev)
930 {
931 	struct generic_pm_domain *genpd;
932 	bool (*suspend_ok)(struct device *__dev);
933 	struct generic_pm_domain_data *gpd_data = dev_gpd_data(dev);
934 	struct gpd_timing_data *td = gpd_data->td;
935 	bool runtime_pm = pm_runtime_enabled(dev);
936 	ktime_t time_start = 0;
937 	s64 elapsed_ns;
938 	int ret;
939 
940 	dev_dbg(dev, "%s()\n", __func__);
941 
942 	genpd = dev_to_genpd(dev);
943 	if (IS_ERR(genpd))
944 		return -EINVAL;
945 
946 	/*
947 	 * A runtime PM centric subsystem/driver may re-use the runtime PM
948 	 * callbacks for other purposes than runtime PM. In those scenarios
949 	 * runtime PM is disabled. Under these circumstances, we shall skip
950 	 * validating/measuring the PM QoS latency.
951 	 */
952 	suspend_ok = genpd->gov ? genpd->gov->suspend_ok : NULL;
953 	if (runtime_pm && suspend_ok && !suspend_ok(dev))
954 		return -EBUSY;
955 
956 	/* Measure suspend latency. */
957 	if (td && runtime_pm)
958 		time_start = ktime_get();
959 
960 	ret = __genpd_runtime_suspend(dev);
961 	if (ret)
962 		return ret;
963 
964 	ret = genpd_stop_dev(genpd, dev);
965 	if (ret) {
966 		__genpd_runtime_resume(dev);
967 		return ret;
968 	}
969 
970 	/* Update suspend latency value if the measured time exceeds it. */
971 	if (td && runtime_pm) {
972 		elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
973 		if (elapsed_ns > td->suspend_latency_ns) {
974 			td->suspend_latency_ns = elapsed_ns;
975 			dev_dbg(dev, "suspend latency exceeded, %lld ns\n",
976 				elapsed_ns);
977 			genpd->gd->max_off_time_changed = true;
978 			td->constraint_changed = true;
979 		}
980 	}
981 
982 	/*
983 	 * If power.irq_safe is set, this routine may be run with
984 	 * IRQs disabled, so suspend only if the PM domain also is irq_safe.
985 	 */
986 	if (irq_safe_dev_in_sleep_domain(dev, genpd))
987 		return 0;
988 
989 	genpd_lock(genpd);
990 	genpd_power_off(genpd, true, 0);
991 	gpd_data->rpm_pstate = genpd_drop_performance_state(dev);
992 	genpd_unlock(genpd);
993 
994 	return 0;
995 }
996 
997 /**
998  * genpd_runtime_resume - Resume a device belonging to I/O PM domain.
999  * @dev: Device to resume.
1000  *
1001  * Carry out a runtime resume of a device under the assumption that its
1002  * pm_domain field points to the domain member of an object of type
1003  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
1004  */
1005 static int genpd_runtime_resume(struct device *dev)
1006 {
1007 	struct generic_pm_domain *genpd;
1008 	struct generic_pm_domain_data *gpd_data = dev_gpd_data(dev);
1009 	struct gpd_timing_data *td = gpd_data->td;
1010 	bool timed = td && pm_runtime_enabled(dev);
1011 	ktime_t time_start = 0;
1012 	s64 elapsed_ns;
1013 	int ret;
1014 
1015 	dev_dbg(dev, "%s()\n", __func__);
1016 
1017 	genpd = dev_to_genpd(dev);
1018 	if (IS_ERR(genpd))
1019 		return -EINVAL;
1020 
1021 	/*
1022 	 * As we don't power off a non IRQ safe domain, which holds
1023 	 * an IRQ safe device, we don't need to restore power to it.
1024 	 */
1025 	if (irq_safe_dev_in_sleep_domain(dev, genpd))
1026 		goto out;
1027 
1028 	genpd_lock(genpd);
1029 	genpd_restore_performance_state(dev, gpd_data->rpm_pstate);
1030 	ret = genpd_power_on(genpd, 0);
1031 	genpd_unlock(genpd);
1032 
1033 	if (ret)
1034 		return ret;
1035 
1036  out:
1037 	/* Measure resume latency. */
1038 	if (timed)
1039 		time_start = ktime_get();
1040 
1041 	ret = genpd_start_dev(genpd, dev);
1042 	if (ret)
1043 		goto err_poweroff;
1044 
1045 	ret = __genpd_runtime_resume(dev);
1046 	if (ret)
1047 		goto err_stop;
1048 
1049 	/* Update resume latency value if the measured time exceeds it. */
1050 	if (timed) {
1051 		elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
1052 		if (elapsed_ns > td->resume_latency_ns) {
1053 			td->resume_latency_ns = elapsed_ns;
1054 			dev_dbg(dev, "resume latency exceeded, %lld ns\n",
1055 				elapsed_ns);
1056 			genpd->gd->max_off_time_changed = true;
1057 			td->constraint_changed = true;
1058 		}
1059 	}
1060 
1061 	return 0;
1062 
1063 err_stop:
1064 	genpd_stop_dev(genpd, dev);
1065 err_poweroff:
1066 	if (!pm_runtime_is_irq_safe(dev) || genpd_is_irq_safe(genpd)) {
1067 		genpd_lock(genpd);
1068 		genpd_power_off(genpd, true, 0);
1069 		gpd_data->rpm_pstate = genpd_drop_performance_state(dev);
1070 		genpd_unlock(genpd);
1071 	}
1072 
1073 	return ret;
1074 }
1075 
1076 static bool pd_ignore_unused;
1077 static int __init pd_ignore_unused_setup(char *__unused)
1078 {
1079 	pd_ignore_unused = true;
1080 	return 1;
1081 }
1082 __setup("pd_ignore_unused", pd_ignore_unused_setup);
1083 
1084 /**
1085  * genpd_power_off_unused - Power off all PM domains with no devices in use.
1086  */
1087 static int __init genpd_power_off_unused(void)
1088 {
1089 	struct generic_pm_domain *genpd;
1090 
1091 	if (pd_ignore_unused) {
1092 		pr_warn("genpd: Not disabling unused power domains\n");
1093 		return 0;
1094 	}
1095 
1096 	mutex_lock(&gpd_list_lock);
1097 
1098 	list_for_each_entry(genpd, &gpd_list, gpd_list_node)
1099 		genpd_queue_power_off_work(genpd);
1100 
1101 	mutex_unlock(&gpd_list_lock);
1102 
1103 	return 0;
1104 }
1105 late_initcall_sync(genpd_power_off_unused);
1106 
1107 #ifdef CONFIG_PM_SLEEP
1108 
1109 /**
1110  * genpd_sync_power_off - Synchronously power off a PM domain and its parents.
1111  * @genpd: PM domain to power off, if possible.
1112  * @use_lock: use the lock.
1113  * @depth: nesting count for lockdep.
1114  *
1115  * Check if the given PM domain can be powered off (during system suspend or
1116  * hibernation) and do that if so.  Also, in that case propagate to its parents.
1117  *
1118  * This function is only called in "noirq" and "syscore" stages of system power
1119  * transitions. The "noirq" callbacks may be executed asynchronously, thus in
1120  * these cases the lock must be held.
1121  */
1122 static void genpd_sync_power_off(struct generic_pm_domain *genpd, bool use_lock,
1123 				 unsigned int depth)
1124 {
1125 	struct gpd_link *link;
1126 
1127 	if (!genpd_status_on(genpd) || genpd_is_always_on(genpd))
1128 		return;
1129 
1130 	if (genpd->suspended_count != genpd->device_count
1131 	    || atomic_read(&genpd->sd_count) > 0)
1132 		return;
1133 
1134 	/* Check that the children are in their deepest (powered-off) state. */
1135 	list_for_each_entry(link, &genpd->parent_links, parent_node) {
1136 		struct generic_pm_domain *child = link->child;
1137 		if (child->state_idx < child->state_count - 1)
1138 			return;
1139 	}
1140 
1141 	/* Choose the deepest state when suspending */
1142 	genpd->state_idx = genpd->state_count - 1;
1143 	if (_genpd_power_off(genpd, false))
1144 		return;
1145 
1146 	genpd->status = GENPD_STATE_OFF;
1147 
1148 	list_for_each_entry(link, &genpd->child_links, child_node) {
1149 		genpd_sd_counter_dec(link->parent);
1150 
1151 		if (use_lock)
1152 			genpd_lock_nested(link->parent, depth + 1);
1153 
1154 		genpd_sync_power_off(link->parent, use_lock, depth + 1);
1155 
1156 		if (use_lock)
1157 			genpd_unlock(link->parent);
1158 	}
1159 }
1160 
1161 /**
1162  * genpd_sync_power_on - Synchronously power on a PM domain and its parents.
1163  * @genpd: PM domain to power on.
1164  * @use_lock: use the lock.
1165  * @depth: nesting count for lockdep.
1166  *
1167  * This function is only called in "noirq" and "syscore" stages of system power
1168  * transitions. The "noirq" callbacks may be executed asynchronously, thus in
1169  * these cases the lock must be held.
1170  */
1171 static void genpd_sync_power_on(struct generic_pm_domain *genpd, bool use_lock,
1172 				unsigned int depth)
1173 {
1174 	struct gpd_link *link;
1175 
1176 	if (genpd_status_on(genpd))
1177 		return;
1178 
1179 	list_for_each_entry(link, &genpd->child_links, child_node) {
1180 		genpd_sd_counter_inc(link->parent);
1181 
1182 		if (use_lock)
1183 			genpd_lock_nested(link->parent, depth + 1);
1184 
1185 		genpd_sync_power_on(link->parent, use_lock, depth + 1);
1186 
1187 		if (use_lock)
1188 			genpd_unlock(link->parent);
1189 	}
1190 
1191 	_genpd_power_on(genpd, false);
1192 	genpd->status = GENPD_STATE_ON;
1193 }
1194 
1195 /**
1196  * genpd_prepare - Start power transition of a device in a PM domain.
1197  * @dev: Device to start the transition of.
1198  *
1199  * Start a power transition of a device (during a system-wide power transition)
1200  * under the assumption that its pm_domain field points to the domain member of
1201  * an object of type struct generic_pm_domain representing a PM domain
1202  * consisting of I/O devices.
1203  */
1204 static int genpd_prepare(struct device *dev)
1205 {
1206 	struct generic_pm_domain *genpd;
1207 	int ret;
1208 
1209 	dev_dbg(dev, "%s()\n", __func__);
1210 
1211 	genpd = dev_to_genpd(dev);
1212 	if (IS_ERR(genpd))
1213 		return -EINVAL;
1214 
1215 	genpd_lock(genpd);
1216 
1217 	if (genpd->prepared_count++ == 0)
1218 		genpd->suspended_count = 0;
1219 
1220 	genpd_unlock(genpd);
1221 
1222 	ret = pm_generic_prepare(dev);
1223 	if (ret < 0) {
1224 		genpd_lock(genpd);
1225 
1226 		genpd->prepared_count--;
1227 
1228 		genpd_unlock(genpd);
1229 	}
1230 
1231 	/* Never return 1, as genpd don't cope with the direct_complete path. */
1232 	return ret >= 0 ? 0 : ret;
1233 }
1234 
1235 /**
1236  * genpd_finish_suspend - Completion of suspend or hibernation of device in an
1237  *   I/O pm domain.
1238  * @dev: Device to suspend.
1239  * @suspend_noirq: Generic suspend_noirq callback.
1240  * @resume_noirq: Generic resume_noirq callback.
1241  *
1242  * Stop the device and remove power from the domain if all devices in it have
1243  * been stopped.
1244  */
1245 static int genpd_finish_suspend(struct device *dev,
1246 				int (*suspend_noirq)(struct device *dev),
1247 				int (*resume_noirq)(struct device *dev))
1248 {
1249 	struct generic_pm_domain *genpd;
1250 	int ret = 0;
1251 
1252 	genpd = dev_to_genpd(dev);
1253 	if (IS_ERR(genpd))
1254 		return -EINVAL;
1255 
1256 	ret = suspend_noirq(dev);
1257 	if (ret)
1258 		return ret;
1259 
1260 	if (device_wakeup_path(dev) && genpd_is_active_wakeup(genpd))
1261 		return 0;
1262 
1263 	if (genpd->dev_ops.stop && genpd->dev_ops.start &&
1264 	    !pm_runtime_status_suspended(dev)) {
1265 		ret = genpd_stop_dev(genpd, dev);
1266 		if (ret) {
1267 			resume_noirq(dev);
1268 			return ret;
1269 		}
1270 	}
1271 
1272 	genpd_lock(genpd);
1273 	genpd->suspended_count++;
1274 	genpd_sync_power_off(genpd, true, 0);
1275 	genpd_unlock(genpd);
1276 
1277 	return 0;
1278 }
1279 
1280 /**
1281  * genpd_suspend_noirq - Completion of suspend of device in an I/O PM domain.
1282  * @dev: Device to suspend.
1283  *
1284  * Stop the device and remove power from the domain if all devices in it have
1285  * been stopped.
1286  */
1287 static int genpd_suspend_noirq(struct device *dev)
1288 {
1289 	dev_dbg(dev, "%s()\n", __func__);
1290 
1291 	return genpd_finish_suspend(dev,
1292 				    pm_generic_suspend_noirq,
1293 				    pm_generic_resume_noirq);
1294 }
1295 
1296 /**
1297  * genpd_finish_resume - Completion of resume of device in an I/O PM domain.
1298  * @dev: Device to resume.
1299  * @resume_noirq: Generic resume_noirq callback.
1300  *
1301  * Restore power to the device's PM domain, if necessary, and start the device.
1302  */
1303 static int genpd_finish_resume(struct device *dev,
1304 			       int (*resume_noirq)(struct device *dev))
1305 {
1306 	struct generic_pm_domain *genpd;
1307 	int ret;
1308 
1309 	dev_dbg(dev, "%s()\n", __func__);
1310 
1311 	genpd = dev_to_genpd(dev);
1312 	if (IS_ERR(genpd))
1313 		return -EINVAL;
1314 
1315 	if (device_wakeup_path(dev) && genpd_is_active_wakeup(genpd))
1316 		return resume_noirq(dev);
1317 
1318 	genpd_lock(genpd);
1319 	genpd_sync_power_on(genpd, true, 0);
1320 	genpd->suspended_count--;
1321 	genpd_unlock(genpd);
1322 
1323 	if (genpd->dev_ops.stop && genpd->dev_ops.start &&
1324 	    !pm_runtime_status_suspended(dev)) {
1325 		ret = genpd_start_dev(genpd, dev);
1326 		if (ret)
1327 			return ret;
1328 	}
1329 
1330 	return pm_generic_resume_noirq(dev);
1331 }
1332 
1333 /**
1334  * genpd_resume_noirq - Start of resume of device in an I/O PM domain.
1335  * @dev: Device to resume.
1336  *
1337  * Restore power to the device's PM domain, if necessary, and start the device.
1338  */
1339 static int genpd_resume_noirq(struct device *dev)
1340 {
1341 	dev_dbg(dev, "%s()\n", __func__);
1342 
1343 	return genpd_finish_resume(dev, pm_generic_resume_noirq);
1344 }
1345 
1346 /**
1347  * genpd_freeze_noirq - Completion of freezing a device in an I/O PM domain.
1348  * @dev: Device to freeze.
1349  *
1350  * Carry out a late freeze of a device under the assumption that its
1351  * pm_domain field points to the domain member of an object of type
1352  * struct generic_pm_domain representing a power domain consisting of I/O
1353  * devices.
1354  */
1355 static int genpd_freeze_noirq(struct device *dev)
1356 {
1357 	dev_dbg(dev, "%s()\n", __func__);
1358 
1359 	return genpd_finish_suspend(dev,
1360 				    pm_generic_freeze_noirq,
1361 				    pm_generic_thaw_noirq);
1362 }
1363 
1364 /**
1365  * genpd_thaw_noirq - Early thaw of device in an I/O PM domain.
1366  * @dev: Device to thaw.
1367  *
1368  * Start the device, unless power has been removed from the domain already
1369  * before the system transition.
1370  */
1371 static int genpd_thaw_noirq(struct device *dev)
1372 {
1373 	dev_dbg(dev, "%s()\n", __func__);
1374 
1375 	return genpd_finish_resume(dev, pm_generic_thaw_noirq);
1376 }
1377 
1378 /**
1379  * genpd_poweroff_noirq - Completion of hibernation of device in an
1380  *   I/O PM domain.
1381  * @dev: Device to poweroff.
1382  *
1383  * Stop the device and remove power from the domain if all devices in it have
1384  * been stopped.
1385  */
1386 static int genpd_poweroff_noirq(struct device *dev)
1387 {
1388 	dev_dbg(dev, "%s()\n", __func__);
1389 
1390 	return genpd_finish_suspend(dev,
1391 				    pm_generic_poweroff_noirq,
1392 				    pm_generic_restore_noirq);
1393 }
1394 
1395 /**
1396  * genpd_restore_noirq - Start of restore of device in an I/O PM domain.
1397  * @dev: Device to resume.
1398  *
1399  * Make sure the domain will be in the same power state as before the
1400  * hibernation the system is resuming from and start the device if necessary.
1401  */
1402 static int genpd_restore_noirq(struct device *dev)
1403 {
1404 	dev_dbg(dev, "%s()\n", __func__);
1405 
1406 	return genpd_finish_resume(dev, pm_generic_restore_noirq);
1407 }
1408 
1409 /**
1410  * genpd_complete - Complete power transition of a device in a power domain.
1411  * @dev: Device to complete the transition of.
1412  *
1413  * Complete a power transition of a device (during a system-wide power
1414  * transition) under the assumption that its pm_domain field points to the
1415  * domain member of an object of type struct generic_pm_domain representing
1416  * a power domain consisting of I/O devices.
1417  */
1418 static void genpd_complete(struct device *dev)
1419 {
1420 	struct generic_pm_domain *genpd;
1421 
1422 	dev_dbg(dev, "%s()\n", __func__);
1423 
1424 	genpd = dev_to_genpd(dev);
1425 	if (IS_ERR(genpd))
1426 		return;
1427 
1428 	pm_generic_complete(dev);
1429 
1430 	genpd_lock(genpd);
1431 
1432 	genpd->prepared_count--;
1433 	if (!genpd->prepared_count)
1434 		genpd_queue_power_off_work(genpd);
1435 
1436 	genpd_unlock(genpd);
1437 }
1438 
1439 static void genpd_switch_state(struct device *dev, bool suspend)
1440 {
1441 	struct generic_pm_domain *genpd;
1442 	bool use_lock;
1443 
1444 	genpd = dev_to_genpd_safe(dev);
1445 	if (!genpd)
1446 		return;
1447 
1448 	use_lock = genpd_is_irq_safe(genpd);
1449 
1450 	if (use_lock)
1451 		genpd_lock(genpd);
1452 
1453 	if (suspend) {
1454 		genpd->suspended_count++;
1455 		genpd_sync_power_off(genpd, use_lock, 0);
1456 	} else {
1457 		genpd_sync_power_on(genpd, use_lock, 0);
1458 		genpd->suspended_count--;
1459 	}
1460 
1461 	if (use_lock)
1462 		genpd_unlock(genpd);
1463 }
1464 
1465 /**
1466  * dev_pm_genpd_suspend - Synchronously try to suspend the genpd for @dev
1467  * @dev: The device that is attached to the genpd, that can be suspended.
1468  *
1469  * This routine should typically be called for a device that needs to be
1470  * suspended during the syscore suspend phase. It may also be called during
1471  * suspend-to-idle to suspend a corresponding CPU device that is attached to a
1472  * genpd.
1473  */
1474 void dev_pm_genpd_suspend(struct device *dev)
1475 {
1476 	genpd_switch_state(dev, true);
1477 }
1478 EXPORT_SYMBOL_GPL(dev_pm_genpd_suspend);
1479 
1480 /**
1481  * dev_pm_genpd_resume - Synchronously try to resume the genpd for @dev
1482  * @dev: The device that is attached to the genpd, which needs to be resumed.
1483  *
1484  * This routine should typically be called for a device that needs to be resumed
1485  * during the syscore resume phase. It may also be called during suspend-to-idle
1486  * to resume a corresponding CPU device that is attached to a genpd.
1487  */
1488 void dev_pm_genpd_resume(struct device *dev)
1489 {
1490 	genpd_switch_state(dev, false);
1491 }
1492 EXPORT_SYMBOL_GPL(dev_pm_genpd_resume);
1493 
1494 #else /* !CONFIG_PM_SLEEP */
1495 
1496 #define genpd_prepare		NULL
1497 #define genpd_suspend_noirq	NULL
1498 #define genpd_resume_noirq	NULL
1499 #define genpd_freeze_noirq	NULL
1500 #define genpd_thaw_noirq	NULL
1501 #define genpd_poweroff_noirq	NULL
1502 #define genpd_restore_noirq	NULL
1503 #define genpd_complete		NULL
1504 
1505 #endif /* CONFIG_PM_SLEEP */
1506 
1507 static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
1508 							   bool has_governor)
1509 {
1510 	struct generic_pm_domain_data *gpd_data;
1511 	struct gpd_timing_data *td;
1512 	int ret;
1513 
1514 	ret = dev_pm_get_subsys_data(dev);
1515 	if (ret)
1516 		return ERR_PTR(ret);
1517 
1518 	gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
1519 	if (!gpd_data) {
1520 		ret = -ENOMEM;
1521 		goto err_put;
1522 	}
1523 
1524 	gpd_data->base.dev = dev;
1525 	gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
1526 
1527 	/* Allocate data used by a governor. */
1528 	if (has_governor) {
1529 		td = kzalloc(sizeof(*td), GFP_KERNEL);
1530 		if (!td) {
1531 			ret = -ENOMEM;
1532 			goto err_free;
1533 		}
1534 
1535 		td->constraint_changed = true;
1536 		td->effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS;
1537 		td->next_wakeup = KTIME_MAX;
1538 		gpd_data->td = td;
1539 	}
1540 
1541 	spin_lock_irq(&dev->power.lock);
1542 
1543 	if (dev->power.subsys_data->domain_data)
1544 		ret = -EINVAL;
1545 	else
1546 		dev->power.subsys_data->domain_data = &gpd_data->base;
1547 
1548 	spin_unlock_irq(&dev->power.lock);
1549 
1550 	if (ret)
1551 		goto err_free;
1552 
1553 	return gpd_data;
1554 
1555  err_free:
1556 	kfree(gpd_data->td);
1557 	kfree(gpd_data);
1558  err_put:
1559 	dev_pm_put_subsys_data(dev);
1560 	return ERR_PTR(ret);
1561 }
1562 
1563 static void genpd_free_dev_data(struct device *dev,
1564 				struct generic_pm_domain_data *gpd_data)
1565 {
1566 	spin_lock_irq(&dev->power.lock);
1567 
1568 	dev->power.subsys_data->domain_data = NULL;
1569 
1570 	spin_unlock_irq(&dev->power.lock);
1571 
1572 	kfree(gpd_data->td);
1573 	kfree(gpd_data);
1574 	dev_pm_put_subsys_data(dev);
1575 }
1576 
1577 static void genpd_update_cpumask(struct generic_pm_domain *genpd,
1578 				 int cpu, bool set, unsigned int depth)
1579 {
1580 	struct gpd_link *link;
1581 
1582 	if (!genpd_is_cpu_domain(genpd))
1583 		return;
1584 
1585 	list_for_each_entry(link, &genpd->child_links, child_node) {
1586 		struct generic_pm_domain *parent = link->parent;
1587 
1588 		genpd_lock_nested(parent, depth + 1);
1589 		genpd_update_cpumask(parent, cpu, set, depth + 1);
1590 		genpd_unlock(parent);
1591 	}
1592 
1593 	if (set)
1594 		cpumask_set_cpu(cpu, genpd->cpus);
1595 	else
1596 		cpumask_clear_cpu(cpu, genpd->cpus);
1597 }
1598 
1599 static void genpd_set_cpumask(struct generic_pm_domain *genpd, int cpu)
1600 {
1601 	if (cpu >= 0)
1602 		genpd_update_cpumask(genpd, cpu, true, 0);
1603 }
1604 
1605 static void genpd_clear_cpumask(struct generic_pm_domain *genpd, int cpu)
1606 {
1607 	if (cpu >= 0)
1608 		genpd_update_cpumask(genpd, cpu, false, 0);
1609 }
1610 
1611 static int genpd_get_cpu(struct generic_pm_domain *genpd, struct device *dev)
1612 {
1613 	int cpu;
1614 
1615 	if (!genpd_is_cpu_domain(genpd))
1616 		return -1;
1617 
1618 	for_each_possible_cpu(cpu) {
1619 		if (get_cpu_device(cpu) == dev)
1620 			return cpu;
1621 	}
1622 
1623 	return -1;
1624 }
1625 
1626 static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
1627 			    struct device *base_dev)
1628 {
1629 	struct genpd_governor_data *gd = genpd->gd;
1630 	struct generic_pm_domain_data *gpd_data;
1631 	int ret;
1632 
1633 	dev_dbg(dev, "%s()\n", __func__);
1634 
1635 	gpd_data = genpd_alloc_dev_data(dev, gd);
1636 	if (IS_ERR(gpd_data))
1637 		return PTR_ERR(gpd_data);
1638 
1639 	gpd_data->cpu = genpd_get_cpu(genpd, base_dev);
1640 
1641 	ret = genpd->attach_dev ? genpd->attach_dev(genpd, dev) : 0;
1642 	if (ret)
1643 		goto out;
1644 
1645 	genpd_lock(genpd);
1646 
1647 	genpd_set_cpumask(genpd, gpd_data->cpu);
1648 	dev_pm_domain_set(dev, &genpd->domain);
1649 
1650 	genpd->device_count++;
1651 	if (gd)
1652 		gd->max_off_time_changed = true;
1653 
1654 	list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
1655 
1656 	genpd_unlock(genpd);
1657  out:
1658 	if (ret)
1659 		genpd_free_dev_data(dev, gpd_data);
1660 	else
1661 		dev_pm_qos_add_notifier(dev, &gpd_data->nb,
1662 					DEV_PM_QOS_RESUME_LATENCY);
1663 
1664 	return ret;
1665 }
1666 
1667 /**
1668  * pm_genpd_add_device - Add a device to an I/O PM domain.
1669  * @genpd: PM domain to add the device to.
1670  * @dev: Device to be added.
1671  */
1672 int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
1673 {
1674 	int ret;
1675 
1676 	if (!genpd || !dev)
1677 		return -EINVAL;
1678 
1679 	mutex_lock(&gpd_list_lock);
1680 	ret = genpd_add_device(genpd, dev, dev);
1681 	mutex_unlock(&gpd_list_lock);
1682 
1683 	return ret;
1684 }
1685 EXPORT_SYMBOL_GPL(pm_genpd_add_device);
1686 
1687 static int genpd_remove_device(struct generic_pm_domain *genpd,
1688 			       struct device *dev)
1689 {
1690 	struct generic_pm_domain_data *gpd_data;
1691 	struct pm_domain_data *pdd;
1692 	int ret = 0;
1693 
1694 	dev_dbg(dev, "%s()\n", __func__);
1695 
1696 	pdd = dev->power.subsys_data->domain_data;
1697 	gpd_data = to_gpd_data(pdd);
1698 	dev_pm_qos_remove_notifier(dev, &gpd_data->nb,
1699 				   DEV_PM_QOS_RESUME_LATENCY);
1700 
1701 	genpd_lock(genpd);
1702 
1703 	if (genpd->prepared_count > 0) {
1704 		ret = -EAGAIN;
1705 		goto out;
1706 	}
1707 
1708 	genpd->device_count--;
1709 	if (genpd->gd)
1710 		genpd->gd->max_off_time_changed = true;
1711 
1712 	genpd_clear_cpumask(genpd, gpd_data->cpu);
1713 	dev_pm_domain_set(dev, NULL);
1714 
1715 	list_del_init(&pdd->list_node);
1716 
1717 	genpd_unlock(genpd);
1718 
1719 	if (genpd->detach_dev)
1720 		genpd->detach_dev(genpd, dev);
1721 
1722 	genpd_free_dev_data(dev, gpd_data);
1723 
1724 	return 0;
1725 
1726  out:
1727 	genpd_unlock(genpd);
1728 	dev_pm_qos_add_notifier(dev, &gpd_data->nb, DEV_PM_QOS_RESUME_LATENCY);
1729 
1730 	return ret;
1731 }
1732 
1733 /**
1734  * pm_genpd_remove_device - Remove a device from an I/O PM domain.
1735  * @dev: Device to be removed.
1736  */
1737 int pm_genpd_remove_device(struct device *dev)
1738 {
1739 	struct generic_pm_domain *genpd = dev_to_genpd_safe(dev);
1740 
1741 	if (!genpd)
1742 		return -EINVAL;
1743 
1744 	return genpd_remove_device(genpd, dev);
1745 }
1746 EXPORT_SYMBOL_GPL(pm_genpd_remove_device);
1747 
1748 /**
1749  * dev_pm_genpd_add_notifier - Add a genpd power on/off notifier for @dev
1750  *
1751  * @dev: Device that should be associated with the notifier
1752  * @nb: The notifier block to register
1753  *
1754  * Users may call this function to add a genpd power on/off notifier for an
1755  * attached @dev. Only one notifier per device is allowed. The notifier is
1756  * sent when genpd is powering on/off the PM domain.
1757  *
1758  * It is assumed that the user guarantee that the genpd wouldn't be detached
1759  * while this routine is getting called.
1760  *
1761  * Returns 0 on success and negative error values on failures.
1762  */
1763 int dev_pm_genpd_add_notifier(struct device *dev, struct notifier_block *nb)
1764 {
1765 	struct generic_pm_domain *genpd;
1766 	struct generic_pm_domain_data *gpd_data;
1767 	int ret;
1768 
1769 	genpd = dev_to_genpd_safe(dev);
1770 	if (!genpd)
1771 		return -ENODEV;
1772 
1773 	if (WARN_ON(!dev->power.subsys_data ||
1774 		     !dev->power.subsys_data->domain_data))
1775 		return -EINVAL;
1776 
1777 	gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
1778 	if (gpd_data->power_nb)
1779 		return -EEXIST;
1780 
1781 	genpd_lock(genpd);
1782 	ret = raw_notifier_chain_register(&genpd->power_notifiers, nb);
1783 	genpd_unlock(genpd);
1784 
1785 	if (ret) {
1786 		dev_warn(dev, "failed to add notifier for PM domain %s\n",
1787 			 genpd->name);
1788 		return ret;
1789 	}
1790 
1791 	gpd_data->power_nb = nb;
1792 	return 0;
1793 }
1794 EXPORT_SYMBOL_GPL(dev_pm_genpd_add_notifier);
1795 
1796 /**
1797  * dev_pm_genpd_remove_notifier - Remove a genpd power on/off notifier for @dev
1798  *
1799  * @dev: Device that is associated with the notifier
1800  *
1801  * Users may call this function to remove a genpd power on/off notifier for an
1802  * attached @dev.
1803  *
1804  * It is assumed that the user guarantee that the genpd wouldn't be detached
1805  * while this routine is getting called.
1806  *
1807  * Returns 0 on success and negative error values on failures.
1808  */
1809 int dev_pm_genpd_remove_notifier(struct device *dev)
1810 {
1811 	struct generic_pm_domain *genpd;
1812 	struct generic_pm_domain_data *gpd_data;
1813 	int ret;
1814 
1815 	genpd = dev_to_genpd_safe(dev);
1816 	if (!genpd)
1817 		return -ENODEV;
1818 
1819 	if (WARN_ON(!dev->power.subsys_data ||
1820 		     !dev->power.subsys_data->domain_data))
1821 		return -EINVAL;
1822 
1823 	gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
1824 	if (!gpd_data->power_nb)
1825 		return -ENODEV;
1826 
1827 	genpd_lock(genpd);
1828 	ret = raw_notifier_chain_unregister(&genpd->power_notifiers,
1829 					    gpd_data->power_nb);
1830 	genpd_unlock(genpd);
1831 
1832 	if (ret) {
1833 		dev_warn(dev, "failed to remove notifier for PM domain %s\n",
1834 			 genpd->name);
1835 		return ret;
1836 	}
1837 
1838 	gpd_data->power_nb = NULL;
1839 	return 0;
1840 }
1841 EXPORT_SYMBOL_GPL(dev_pm_genpd_remove_notifier);
1842 
1843 static int genpd_add_subdomain(struct generic_pm_domain *genpd,
1844 			       struct generic_pm_domain *subdomain)
1845 {
1846 	struct gpd_link *link, *itr;
1847 	int ret = 0;
1848 
1849 	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
1850 	    || genpd == subdomain)
1851 		return -EINVAL;
1852 
1853 	/*
1854 	 * If the domain can be powered on/off in an IRQ safe
1855 	 * context, ensure that the subdomain can also be
1856 	 * powered on/off in that context.
1857 	 */
1858 	if (!genpd_is_irq_safe(genpd) && genpd_is_irq_safe(subdomain)) {
1859 		WARN(1, "Parent %s of subdomain %s must be IRQ safe\n",
1860 				genpd->name, subdomain->name);
1861 		return -EINVAL;
1862 	}
1863 
1864 	link = kzalloc(sizeof(*link), GFP_KERNEL);
1865 	if (!link)
1866 		return -ENOMEM;
1867 
1868 	genpd_lock(subdomain);
1869 	genpd_lock_nested(genpd, SINGLE_DEPTH_NESTING);
1870 
1871 	if (!genpd_status_on(genpd) && genpd_status_on(subdomain)) {
1872 		ret = -EINVAL;
1873 		goto out;
1874 	}
1875 
1876 	list_for_each_entry(itr, &genpd->parent_links, parent_node) {
1877 		if (itr->child == subdomain && itr->parent == genpd) {
1878 			ret = -EINVAL;
1879 			goto out;
1880 		}
1881 	}
1882 
1883 	link->parent = genpd;
1884 	list_add_tail(&link->parent_node, &genpd->parent_links);
1885 	link->child = subdomain;
1886 	list_add_tail(&link->child_node, &subdomain->child_links);
1887 	if (genpd_status_on(subdomain))
1888 		genpd_sd_counter_inc(genpd);
1889 
1890  out:
1891 	genpd_unlock(genpd);
1892 	genpd_unlock(subdomain);
1893 	if (ret)
1894 		kfree(link);
1895 	return ret;
1896 }
1897 
1898 /**
1899  * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
1900  * @genpd: Leader PM domain to add the subdomain to.
1901  * @subdomain: Subdomain to be added.
1902  */
1903 int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
1904 			   struct generic_pm_domain *subdomain)
1905 {
1906 	int ret;
1907 
1908 	mutex_lock(&gpd_list_lock);
1909 	ret = genpd_add_subdomain(genpd, subdomain);
1910 	mutex_unlock(&gpd_list_lock);
1911 
1912 	return ret;
1913 }
1914 EXPORT_SYMBOL_GPL(pm_genpd_add_subdomain);
1915 
1916 /**
1917  * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
1918  * @genpd: Leader PM domain to remove the subdomain from.
1919  * @subdomain: Subdomain to be removed.
1920  */
1921 int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
1922 			      struct generic_pm_domain *subdomain)
1923 {
1924 	struct gpd_link *l, *link;
1925 	int ret = -EINVAL;
1926 
1927 	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
1928 		return -EINVAL;
1929 
1930 	genpd_lock(subdomain);
1931 	genpd_lock_nested(genpd, SINGLE_DEPTH_NESTING);
1932 
1933 	if (!list_empty(&subdomain->parent_links) || subdomain->device_count) {
1934 		pr_warn("%s: unable to remove subdomain %s\n",
1935 			genpd->name, subdomain->name);
1936 		ret = -EBUSY;
1937 		goto out;
1938 	}
1939 
1940 	list_for_each_entry_safe(link, l, &genpd->parent_links, parent_node) {
1941 		if (link->child != subdomain)
1942 			continue;
1943 
1944 		list_del(&link->parent_node);
1945 		list_del(&link->child_node);
1946 		kfree(link);
1947 		if (genpd_status_on(subdomain))
1948 			genpd_sd_counter_dec(genpd);
1949 
1950 		ret = 0;
1951 		break;
1952 	}
1953 
1954 out:
1955 	genpd_unlock(genpd);
1956 	genpd_unlock(subdomain);
1957 
1958 	return ret;
1959 }
1960 EXPORT_SYMBOL_GPL(pm_genpd_remove_subdomain);
1961 
1962 static void genpd_free_default_power_state(struct genpd_power_state *states,
1963 					   unsigned int state_count)
1964 {
1965 	kfree(states);
1966 }
1967 
1968 static int genpd_set_default_power_state(struct generic_pm_domain *genpd)
1969 {
1970 	struct genpd_power_state *state;
1971 
1972 	state = kzalloc(sizeof(*state), GFP_KERNEL);
1973 	if (!state)
1974 		return -ENOMEM;
1975 
1976 	genpd->states = state;
1977 	genpd->state_count = 1;
1978 	genpd->free_states = genpd_free_default_power_state;
1979 
1980 	return 0;
1981 }
1982 
1983 static int genpd_alloc_data(struct generic_pm_domain *genpd)
1984 {
1985 	struct genpd_governor_data *gd = NULL;
1986 	int ret;
1987 
1988 	if (genpd_is_cpu_domain(genpd) &&
1989 	    !zalloc_cpumask_var(&genpd->cpus, GFP_KERNEL))
1990 		return -ENOMEM;
1991 
1992 	if (genpd->gov) {
1993 		gd = kzalloc(sizeof(*gd), GFP_KERNEL);
1994 		if (!gd) {
1995 			ret = -ENOMEM;
1996 			goto free;
1997 		}
1998 
1999 		gd->max_off_time_ns = -1;
2000 		gd->max_off_time_changed = true;
2001 		gd->next_wakeup = KTIME_MAX;
2002 		gd->next_hrtimer = KTIME_MAX;
2003 	}
2004 
2005 	/* Use only one "off" state if there were no states declared */
2006 	if (genpd->state_count == 0) {
2007 		ret = genpd_set_default_power_state(genpd);
2008 		if (ret)
2009 			goto free;
2010 	}
2011 
2012 	genpd->gd = gd;
2013 	return 0;
2014 
2015 free:
2016 	if (genpd_is_cpu_domain(genpd))
2017 		free_cpumask_var(genpd->cpus);
2018 	kfree(gd);
2019 	return ret;
2020 }
2021 
2022 static void genpd_free_data(struct generic_pm_domain *genpd)
2023 {
2024 	if (genpd_is_cpu_domain(genpd))
2025 		free_cpumask_var(genpd->cpus);
2026 	if (genpd->free_states)
2027 		genpd->free_states(genpd->states, genpd->state_count);
2028 	kfree(genpd->gd);
2029 }
2030 
2031 static void genpd_lock_init(struct generic_pm_domain *genpd)
2032 {
2033 	if (genpd->flags & GENPD_FLAG_IRQ_SAFE) {
2034 		spin_lock_init(&genpd->slock);
2035 		genpd->lock_ops = &genpd_spin_ops;
2036 	} else {
2037 		mutex_init(&genpd->mlock);
2038 		genpd->lock_ops = &genpd_mtx_ops;
2039 	}
2040 }
2041 
2042 /**
2043  * pm_genpd_init - Initialize a generic I/O PM domain object.
2044  * @genpd: PM domain object to initialize.
2045  * @gov: PM domain governor to associate with the domain (may be NULL).
2046  * @is_off: Initial value of the domain's power_is_off field.
2047  *
2048  * Returns 0 on successful initialization, else a negative error code.
2049  */
2050 int pm_genpd_init(struct generic_pm_domain *genpd,
2051 		  struct dev_power_governor *gov, bool is_off)
2052 {
2053 	int ret;
2054 
2055 	if (IS_ERR_OR_NULL(genpd))
2056 		return -EINVAL;
2057 
2058 	INIT_LIST_HEAD(&genpd->parent_links);
2059 	INIT_LIST_HEAD(&genpd->child_links);
2060 	INIT_LIST_HEAD(&genpd->dev_list);
2061 	RAW_INIT_NOTIFIER_HEAD(&genpd->power_notifiers);
2062 	genpd_lock_init(genpd);
2063 	genpd->gov = gov;
2064 	INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
2065 	atomic_set(&genpd->sd_count, 0);
2066 	genpd->status = is_off ? GENPD_STATE_OFF : GENPD_STATE_ON;
2067 	genpd->device_count = 0;
2068 	genpd->provider = NULL;
2069 	genpd->has_provider = false;
2070 	genpd->accounting_time = ktime_get_mono_fast_ns();
2071 	genpd->domain.ops.runtime_suspend = genpd_runtime_suspend;
2072 	genpd->domain.ops.runtime_resume = genpd_runtime_resume;
2073 	genpd->domain.ops.prepare = genpd_prepare;
2074 	genpd->domain.ops.suspend_noirq = genpd_suspend_noirq;
2075 	genpd->domain.ops.resume_noirq = genpd_resume_noirq;
2076 	genpd->domain.ops.freeze_noirq = genpd_freeze_noirq;
2077 	genpd->domain.ops.thaw_noirq = genpd_thaw_noirq;
2078 	genpd->domain.ops.poweroff_noirq = genpd_poweroff_noirq;
2079 	genpd->domain.ops.restore_noirq = genpd_restore_noirq;
2080 	genpd->domain.ops.complete = genpd_complete;
2081 	genpd->domain.start = genpd_dev_pm_start;
2082 
2083 	if (genpd->flags & GENPD_FLAG_PM_CLK) {
2084 		genpd->dev_ops.stop = pm_clk_suspend;
2085 		genpd->dev_ops.start = pm_clk_resume;
2086 	}
2087 
2088 	/* The always-on governor works better with the corresponding flag. */
2089 	if (gov == &pm_domain_always_on_gov)
2090 		genpd->flags |= GENPD_FLAG_RPM_ALWAYS_ON;
2091 
2092 	/* Always-on domains must be powered on at initialization. */
2093 	if ((genpd_is_always_on(genpd) || genpd_is_rpm_always_on(genpd)) &&
2094 			!genpd_status_on(genpd)) {
2095 		pr_err("always-on PM domain %s is not on\n", genpd->name);
2096 		return -EINVAL;
2097 	}
2098 
2099 	/* Multiple states but no governor doesn't make sense. */
2100 	if (!gov && genpd->state_count > 1)
2101 		pr_warn("%s: no governor for states\n", genpd->name);
2102 
2103 	ret = genpd_alloc_data(genpd);
2104 	if (ret)
2105 		return ret;
2106 
2107 	device_initialize(&genpd->dev);
2108 	dev_set_name(&genpd->dev, "%s", genpd->name);
2109 
2110 	mutex_lock(&gpd_list_lock);
2111 	list_add(&genpd->gpd_list_node, &gpd_list);
2112 	mutex_unlock(&gpd_list_lock);
2113 	genpd_debug_add(genpd);
2114 
2115 	return 0;
2116 }
2117 EXPORT_SYMBOL_GPL(pm_genpd_init);
2118 
2119 static int genpd_remove(struct generic_pm_domain *genpd)
2120 {
2121 	struct gpd_link *l, *link;
2122 
2123 	if (IS_ERR_OR_NULL(genpd))
2124 		return -EINVAL;
2125 
2126 	genpd_lock(genpd);
2127 
2128 	if (genpd->has_provider) {
2129 		genpd_unlock(genpd);
2130 		pr_err("Provider present, unable to remove %s\n", genpd->name);
2131 		return -EBUSY;
2132 	}
2133 
2134 	if (!list_empty(&genpd->parent_links) || genpd->device_count) {
2135 		genpd_unlock(genpd);
2136 		pr_err("%s: unable to remove %s\n", __func__, genpd->name);
2137 		return -EBUSY;
2138 	}
2139 
2140 	list_for_each_entry_safe(link, l, &genpd->child_links, child_node) {
2141 		list_del(&link->parent_node);
2142 		list_del(&link->child_node);
2143 		kfree(link);
2144 	}
2145 
2146 	list_del(&genpd->gpd_list_node);
2147 	genpd_unlock(genpd);
2148 	genpd_debug_remove(genpd);
2149 	cancel_work_sync(&genpd->power_off_work);
2150 	genpd_free_data(genpd);
2151 
2152 	pr_debug("%s: removed %s\n", __func__, genpd->name);
2153 
2154 	return 0;
2155 }
2156 
2157 /**
2158  * pm_genpd_remove - Remove a generic I/O PM domain
2159  * @genpd: Pointer to PM domain that is to be removed.
2160  *
2161  * To remove the PM domain, this function:
2162  *  - Removes the PM domain as a subdomain to any parent domains,
2163  *    if it was added.
2164  *  - Removes the PM domain from the list of registered PM domains.
2165  *
2166  * The PM domain will only be removed, if the associated provider has
2167  * been removed, it is not a parent to any other PM domain and has no
2168  * devices associated with it.
2169  */
2170 int pm_genpd_remove(struct generic_pm_domain *genpd)
2171 {
2172 	int ret;
2173 
2174 	mutex_lock(&gpd_list_lock);
2175 	ret = genpd_remove(genpd);
2176 	mutex_unlock(&gpd_list_lock);
2177 
2178 	return ret;
2179 }
2180 EXPORT_SYMBOL_GPL(pm_genpd_remove);
2181 
2182 #ifdef CONFIG_PM_GENERIC_DOMAINS_OF
2183 
2184 /*
2185  * Device Tree based PM domain providers.
2186  *
2187  * The code below implements generic device tree based PM domain providers that
2188  * bind device tree nodes with generic PM domains registered in the system.
2189  *
2190  * Any driver that registers generic PM domains and needs to support binding of
2191  * devices to these domains is supposed to register a PM domain provider, which
2192  * maps a PM domain specifier retrieved from the device tree to a PM domain.
2193  *
2194  * Two simple mapping functions have been provided for convenience:
2195  *  - genpd_xlate_simple() for 1:1 device tree node to PM domain mapping.
2196  *  - genpd_xlate_onecell() for mapping of multiple PM domains per node by
2197  *    index.
2198  */
2199 
2200 /**
2201  * struct of_genpd_provider - PM domain provider registration structure
2202  * @link: Entry in global list of PM domain providers
2203  * @node: Pointer to device tree node of PM domain provider
2204  * @xlate: Provider-specific xlate callback mapping a set of specifier cells
2205  *         into a PM domain.
2206  * @data: context pointer to be passed into @xlate callback
2207  */
2208 struct of_genpd_provider {
2209 	struct list_head link;
2210 	struct device_node *node;
2211 	genpd_xlate_t xlate;
2212 	void *data;
2213 };
2214 
2215 /* List of registered PM domain providers. */
2216 static LIST_HEAD(of_genpd_providers);
2217 /* Mutex to protect the list above. */
2218 static DEFINE_MUTEX(of_genpd_mutex);
2219 
2220 /**
2221  * genpd_xlate_simple() - Xlate function for direct node-domain mapping
2222  * @genpdspec: OF phandle args to map into a PM domain
2223  * @data: xlate function private data - pointer to struct generic_pm_domain
2224  *
2225  * This is a generic xlate function that can be used to model PM domains that
2226  * have their own device tree nodes. The private data of xlate function needs
2227  * to be a valid pointer to struct generic_pm_domain.
2228  */
2229 static struct generic_pm_domain *genpd_xlate_simple(
2230 					struct of_phandle_args *genpdspec,
2231 					void *data)
2232 {
2233 	return data;
2234 }
2235 
2236 /**
2237  * genpd_xlate_onecell() - Xlate function using a single index.
2238  * @genpdspec: OF phandle args to map into a PM domain
2239  * @data: xlate function private data - pointer to struct genpd_onecell_data
2240  *
2241  * This is a generic xlate function that can be used to model simple PM domain
2242  * controllers that have one device tree node and provide multiple PM domains.
2243  * A single cell is used as an index into an array of PM domains specified in
2244  * the genpd_onecell_data struct when registering the provider.
2245  */
2246 static struct generic_pm_domain *genpd_xlate_onecell(
2247 					struct of_phandle_args *genpdspec,
2248 					void *data)
2249 {
2250 	struct genpd_onecell_data *genpd_data = data;
2251 	unsigned int idx = genpdspec->args[0];
2252 
2253 	if (genpdspec->args_count != 1)
2254 		return ERR_PTR(-EINVAL);
2255 
2256 	if (idx >= genpd_data->num_domains) {
2257 		pr_err("%s: invalid domain index %u\n", __func__, idx);
2258 		return ERR_PTR(-EINVAL);
2259 	}
2260 
2261 	if (!genpd_data->domains[idx])
2262 		return ERR_PTR(-ENOENT);
2263 
2264 	return genpd_data->domains[idx];
2265 }
2266 
2267 /**
2268  * genpd_add_provider() - Register a PM domain provider for a node
2269  * @np: Device node pointer associated with the PM domain provider.
2270  * @xlate: Callback for decoding PM domain from phandle arguments.
2271  * @data: Context pointer for @xlate callback.
2272  */
2273 static int genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
2274 			      void *data)
2275 {
2276 	struct of_genpd_provider *cp;
2277 
2278 	cp = kzalloc(sizeof(*cp), GFP_KERNEL);
2279 	if (!cp)
2280 		return -ENOMEM;
2281 
2282 	cp->node = of_node_get(np);
2283 	cp->data = data;
2284 	cp->xlate = xlate;
2285 	fwnode_dev_initialized(&np->fwnode, true);
2286 
2287 	mutex_lock(&of_genpd_mutex);
2288 	list_add(&cp->link, &of_genpd_providers);
2289 	mutex_unlock(&of_genpd_mutex);
2290 	pr_debug("Added domain provider from %pOF\n", np);
2291 
2292 	return 0;
2293 }
2294 
2295 static bool genpd_present(const struct generic_pm_domain *genpd)
2296 {
2297 	bool ret = false;
2298 	const struct generic_pm_domain *gpd;
2299 
2300 	mutex_lock(&gpd_list_lock);
2301 	list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
2302 		if (gpd == genpd) {
2303 			ret = true;
2304 			break;
2305 		}
2306 	}
2307 	mutex_unlock(&gpd_list_lock);
2308 
2309 	return ret;
2310 }
2311 
2312 /**
2313  * of_genpd_add_provider_simple() - Register a simple PM domain provider
2314  * @np: Device node pointer associated with the PM domain provider.
2315  * @genpd: Pointer to PM domain associated with the PM domain provider.
2316  */
2317 int of_genpd_add_provider_simple(struct device_node *np,
2318 				 struct generic_pm_domain *genpd)
2319 {
2320 	int ret;
2321 
2322 	if (!np || !genpd)
2323 		return -EINVAL;
2324 
2325 	if (!genpd_present(genpd))
2326 		return -EINVAL;
2327 
2328 	genpd->dev.of_node = np;
2329 
2330 	/* Parse genpd OPP table */
2331 	if (genpd->set_performance_state) {
2332 		ret = dev_pm_opp_of_add_table(&genpd->dev);
2333 		if (ret)
2334 			return dev_err_probe(&genpd->dev, ret, "Failed to add OPP table\n");
2335 
2336 		/*
2337 		 * Save table for faster processing while setting performance
2338 		 * state.
2339 		 */
2340 		genpd->opp_table = dev_pm_opp_get_opp_table(&genpd->dev);
2341 		WARN_ON(IS_ERR(genpd->opp_table));
2342 	}
2343 
2344 	ret = genpd_add_provider(np, genpd_xlate_simple, genpd);
2345 	if (ret) {
2346 		if (genpd->set_performance_state) {
2347 			dev_pm_opp_put_opp_table(genpd->opp_table);
2348 			dev_pm_opp_of_remove_table(&genpd->dev);
2349 		}
2350 
2351 		return ret;
2352 	}
2353 
2354 	genpd->provider = &np->fwnode;
2355 	genpd->has_provider = true;
2356 
2357 	return 0;
2358 }
2359 EXPORT_SYMBOL_GPL(of_genpd_add_provider_simple);
2360 
2361 /**
2362  * of_genpd_add_provider_onecell() - Register a onecell PM domain provider
2363  * @np: Device node pointer associated with the PM domain provider.
2364  * @data: Pointer to the data associated with the PM domain provider.
2365  */
2366 int of_genpd_add_provider_onecell(struct device_node *np,
2367 				  struct genpd_onecell_data *data)
2368 {
2369 	struct generic_pm_domain *genpd;
2370 	unsigned int i;
2371 	int ret = -EINVAL;
2372 
2373 	if (!np || !data)
2374 		return -EINVAL;
2375 
2376 	if (!data->xlate)
2377 		data->xlate = genpd_xlate_onecell;
2378 
2379 	for (i = 0; i < data->num_domains; i++) {
2380 		genpd = data->domains[i];
2381 
2382 		if (!genpd)
2383 			continue;
2384 		if (!genpd_present(genpd))
2385 			goto error;
2386 
2387 		genpd->dev.of_node = np;
2388 
2389 		/* Parse genpd OPP table */
2390 		if (genpd->set_performance_state) {
2391 			ret = dev_pm_opp_of_add_table_indexed(&genpd->dev, i);
2392 			if (ret) {
2393 				dev_err_probe(&genpd->dev, ret,
2394 					      "Failed to add OPP table for index %d\n", i);
2395 				goto error;
2396 			}
2397 
2398 			/*
2399 			 * Save table for faster processing while setting
2400 			 * performance state.
2401 			 */
2402 			genpd->opp_table = dev_pm_opp_get_opp_table(&genpd->dev);
2403 			WARN_ON(IS_ERR(genpd->opp_table));
2404 		}
2405 
2406 		genpd->provider = &np->fwnode;
2407 		genpd->has_provider = true;
2408 	}
2409 
2410 	ret = genpd_add_provider(np, data->xlate, data);
2411 	if (ret < 0)
2412 		goto error;
2413 
2414 	return 0;
2415 
2416 error:
2417 	while (i--) {
2418 		genpd = data->domains[i];
2419 
2420 		if (!genpd)
2421 			continue;
2422 
2423 		genpd->provider = NULL;
2424 		genpd->has_provider = false;
2425 
2426 		if (genpd->set_performance_state) {
2427 			dev_pm_opp_put_opp_table(genpd->opp_table);
2428 			dev_pm_opp_of_remove_table(&genpd->dev);
2429 		}
2430 	}
2431 
2432 	return ret;
2433 }
2434 EXPORT_SYMBOL_GPL(of_genpd_add_provider_onecell);
2435 
2436 /**
2437  * of_genpd_del_provider() - Remove a previously registered PM domain provider
2438  * @np: Device node pointer associated with the PM domain provider
2439  */
2440 void of_genpd_del_provider(struct device_node *np)
2441 {
2442 	struct of_genpd_provider *cp, *tmp;
2443 	struct generic_pm_domain *gpd;
2444 
2445 	mutex_lock(&gpd_list_lock);
2446 	mutex_lock(&of_genpd_mutex);
2447 	list_for_each_entry_safe(cp, tmp, &of_genpd_providers, link) {
2448 		if (cp->node == np) {
2449 			/*
2450 			 * For each PM domain associated with the
2451 			 * provider, set the 'has_provider' to false
2452 			 * so that the PM domain can be safely removed.
2453 			 */
2454 			list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
2455 				if (gpd->provider == &np->fwnode) {
2456 					gpd->has_provider = false;
2457 
2458 					if (!gpd->set_performance_state)
2459 						continue;
2460 
2461 					dev_pm_opp_put_opp_table(gpd->opp_table);
2462 					dev_pm_opp_of_remove_table(&gpd->dev);
2463 				}
2464 			}
2465 
2466 			fwnode_dev_initialized(&cp->node->fwnode, false);
2467 			list_del(&cp->link);
2468 			of_node_put(cp->node);
2469 			kfree(cp);
2470 			break;
2471 		}
2472 	}
2473 	mutex_unlock(&of_genpd_mutex);
2474 	mutex_unlock(&gpd_list_lock);
2475 }
2476 EXPORT_SYMBOL_GPL(of_genpd_del_provider);
2477 
2478 /**
2479  * genpd_get_from_provider() - Look-up PM domain
2480  * @genpdspec: OF phandle args to use for look-up
2481  *
2482  * Looks for a PM domain provider under the node specified by @genpdspec and if
2483  * found, uses xlate function of the provider to map phandle args to a PM
2484  * domain.
2485  *
2486  * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR()
2487  * on failure.
2488  */
2489 static struct generic_pm_domain *genpd_get_from_provider(
2490 					struct of_phandle_args *genpdspec)
2491 {
2492 	struct generic_pm_domain *genpd = ERR_PTR(-ENOENT);
2493 	struct of_genpd_provider *provider;
2494 
2495 	if (!genpdspec)
2496 		return ERR_PTR(-EINVAL);
2497 
2498 	mutex_lock(&of_genpd_mutex);
2499 
2500 	/* Check if we have such a provider in our array */
2501 	list_for_each_entry(provider, &of_genpd_providers, link) {
2502 		if (provider->node == genpdspec->np)
2503 			genpd = provider->xlate(genpdspec, provider->data);
2504 		if (!IS_ERR(genpd))
2505 			break;
2506 	}
2507 
2508 	mutex_unlock(&of_genpd_mutex);
2509 
2510 	return genpd;
2511 }
2512 
2513 /**
2514  * of_genpd_add_device() - Add a device to an I/O PM domain
2515  * @genpdspec: OF phandle args to use for look-up PM domain
2516  * @dev: Device to be added.
2517  *
2518  * Looks-up an I/O PM domain based upon phandle args provided and adds
2519  * the device to the PM domain. Returns a negative error code on failure.
2520  */
2521 int of_genpd_add_device(struct of_phandle_args *genpdspec, struct device *dev)
2522 {
2523 	struct generic_pm_domain *genpd;
2524 	int ret;
2525 
2526 	if (!dev)
2527 		return -EINVAL;
2528 
2529 	mutex_lock(&gpd_list_lock);
2530 
2531 	genpd = genpd_get_from_provider(genpdspec);
2532 	if (IS_ERR(genpd)) {
2533 		ret = PTR_ERR(genpd);
2534 		goto out;
2535 	}
2536 
2537 	ret = genpd_add_device(genpd, dev, dev);
2538 
2539 out:
2540 	mutex_unlock(&gpd_list_lock);
2541 
2542 	return ret;
2543 }
2544 EXPORT_SYMBOL_GPL(of_genpd_add_device);
2545 
2546 /**
2547  * of_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
2548  * @parent_spec: OF phandle args to use for parent PM domain look-up
2549  * @subdomain_spec: OF phandle args to use for subdomain look-up
2550  *
2551  * Looks-up a parent PM domain and subdomain based upon phandle args
2552  * provided and adds the subdomain to the parent PM domain. Returns a
2553  * negative error code on failure.
2554  */
2555 int of_genpd_add_subdomain(struct of_phandle_args *parent_spec,
2556 			   struct of_phandle_args *subdomain_spec)
2557 {
2558 	struct generic_pm_domain *parent, *subdomain;
2559 	int ret;
2560 
2561 	mutex_lock(&gpd_list_lock);
2562 
2563 	parent = genpd_get_from_provider(parent_spec);
2564 	if (IS_ERR(parent)) {
2565 		ret = PTR_ERR(parent);
2566 		goto out;
2567 	}
2568 
2569 	subdomain = genpd_get_from_provider(subdomain_spec);
2570 	if (IS_ERR(subdomain)) {
2571 		ret = PTR_ERR(subdomain);
2572 		goto out;
2573 	}
2574 
2575 	ret = genpd_add_subdomain(parent, subdomain);
2576 
2577 out:
2578 	mutex_unlock(&gpd_list_lock);
2579 
2580 	return ret == -ENOENT ? -EPROBE_DEFER : ret;
2581 }
2582 EXPORT_SYMBOL_GPL(of_genpd_add_subdomain);
2583 
2584 /**
2585  * of_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
2586  * @parent_spec: OF phandle args to use for parent PM domain look-up
2587  * @subdomain_spec: OF phandle args to use for subdomain look-up
2588  *
2589  * Looks-up a parent PM domain and subdomain based upon phandle args
2590  * provided and removes the subdomain from the parent PM domain. Returns a
2591  * negative error code on failure.
2592  */
2593 int of_genpd_remove_subdomain(struct of_phandle_args *parent_spec,
2594 			      struct of_phandle_args *subdomain_spec)
2595 {
2596 	struct generic_pm_domain *parent, *subdomain;
2597 	int ret;
2598 
2599 	mutex_lock(&gpd_list_lock);
2600 
2601 	parent = genpd_get_from_provider(parent_spec);
2602 	if (IS_ERR(parent)) {
2603 		ret = PTR_ERR(parent);
2604 		goto out;
2605 	}
2606 
2607 	subdomain = genpd_get_from_provider(subdomain_spec);
2608 	if (IS_ERR(subdomain)) {
2609 		ret = PTR_ERR(subdomain);
2610 		goto out;
2611 	}
2612 
2613 	ret = pm_genpd_remove_subdomain(parent, subdomain);
2614 
2615 out:
2616 	mutex_unlock(&gpd_list_lock);
2617 
2618 	return ret;
2619 }
2620 EXPORT_SYMBOL_GPL(of_genpd_remove_subdomain);
2621 
2622 /**
2623  * of_genpd_remove_last - Remove the last PM domain registered for a provider
2624  * @np: Pointer to device node associated with provider
2625  *
2626  * Find the last PM domain that was added by a particular provider and
2627  * remove this PM domain from the list of PM domains. The provider is
2628  * identified by the 'provider' device structure that is passed. The PM
2629  * domain will only be removed, if the provider associated with domain
2630  * has been removed.
2631  *
2632  * Returns a valid pointer to struct generic_pm_domain on success or
2633  * ERR_PTR() on failure.
2634  */
2635 struct generic_pm_domain *of_genpd_remove_last(struct device_node *np)
2636 {
2637 	struct generic_pm_domain *gpd, *tmp, *genpd = ERR_PTR(-ENOENT);
2638 	int ret;
2639 
2640 	if (IS_ERR_OR_NULL(np))
2641 		return ERR_PTR(-EINVAL);
2642 
2643 	mutex_lock(&gpd_list_lock);
2644 	list_for_each_entry_safe(gpd, tmp, &gpd_list, gpd_list_node) {
2645 		if (gpd->provider == &np->fwnode) {
2646 			ret = genpd_remove(gpd);
2647 			genpd = ret ? ERR_PTR(ret) : gpd;
2648 			break;
2649 		}
2650 	}
2651 	mutex_unlock(&gpd_list_lock);
2652 
2653 	return genpd;
2654 }
2655 EXPORT_SYMBOL_GPL(of_genpd_remove_last);
2656 
2657 static void genpd_release_dev(struct device *dev)
2658 {
2659 	of_node_put(dev->of_node);
2660 	kfree(dev);
2661 }
2662 
2663 static struct bus_type genpd_bus_type = {
2664 	.name		= "genpd",
2665 };
2666 
2667 /**
2668  * genpd_dev_pm_detach - Detach a device from its PM domain.
2669  * @dev: Device to detach.
2670  * @power_off: Currently not used
2671  *
2672  * Try to locate a corresponding generic PM domain, which the device was
2673  * attached to previously. If such is found, the device is detached from it.
2674  */
2675 static void genpd_dev_pm_detach(struct device *dev, bool power_off)
2676 {
2677 	struct generic_pm_domain *pd;
2678 	unsigned int i;
2679 	int ret = 0;
2680 
2681 	pd = dev_to_genpd(dev);
2682 	if (IS_ERR(pd))
2683 		return;
2684 
2685 	dev_dbg(dev, "removing from PM domain %s\n", pd->name);
2686 
2687 	/* Drop the default performance state */
2688 	if (dev_gpd_data(dev)->default_pstate) {
2689 		dev_pm_genpd_set_performance_state(dev, 0);
2690 		dev_gpd_data(dev)->default_pstate = 0;
2691 	}
2692 
2693 	for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
2694 		ret = genpd_remove_device(pd, dev);
2695 		if (ret != -EAGAIN)
2696 			break;
2697 
2698 		mdelay(i);
2699 		cond_resched();
2700 	}
2701 
2702 	if (ret < 0) {
2703 		dev_err(dev, "failed to remove from PM domain %s: %d",
2704 			pd->name, ret);
2705 		return;
2706 	}
2707 
2708 	/* Check if PM domain can be powered off after removing this device. */
2709 	genpd_queue_power_off_work(pd);
2710 
2711 	/* Unregister the device if it was created by genpd. */
2712 	if (dev->bus == &genpd_bus_type)
2713 		device_unregister(dev);
2714 }
2715 
2716 static void genpd_dev_pm_sync(struct device *dev)
2717 {
2718 	struct generic_pm_domain *pd;
2719 
2720 	pd = dev_to_genpd(dev);
2721 	if (IS_ERR(pd))
2722 		return;
2723 
2724 	genpd_queue_power_off_work(pd);
2725 }
2726 
2727 static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
2728 				 unsigned int index, bool power_on)
2729 {
2730 	struct of_phandle_args pd_args;
2731 	struct generic_pm_domain *pd;
2732 	int pstate;
2733 	int ret;
2734 
2735 	ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
2736 				"#power-domain-cells", index, &pd_args);
2737 	if (ret < 0)
2738 		return ret;
2739 
2740 	mutex_lock(&gpd_list_lock);
2741 	pd = genpd_get_from_provider(&pd_args);
2742 	of_node_put(pd_args.np);
2743 	if (IS_ERR(pd)) {
2744 		mutex_unlock(&gpd_list_lock);
2745 		dev_dbg(dev, "%s() failed to find PM domain: %ld\n",
2746 			__func__, PTR_ERR(pd));
2747 		return driver_deferred_probe_check_state(base_dev);
2748 	}
2749 
2750 	dev_dbg(dev, "adding to PM domain %s\n", pd->name);
2751 
2752 	ret = genpd_add_device(pd, dev, base_dev);
2753 	mutex_unlock(&gpd_list_lock);
2754 
2755 	if (ret < 0)
2756 		return dev_err_probe(dev, ret, "failed to add to PM domain %s\n", pd->name);
2757 
2758 	dev->pm_domain->detach = genpd_dev_pm_detach;
2759 	dev->pm_domain->sync = genpd_dev_pm_sync;
2760 
2761 	/* Set the default performance state */
2762 	pstate = of_get_required_opp_performance_state(dev->of_node, index);
2763 	if (pstate < 0 && pstate != -ENODEV && pstate != -EOPNOTSUPP) {
2764 		ret = pstate;
2765 		goto err;
2766 	} else if (pstate > 0) {
2767 		ret = dev_pm_genpd_set_performance_state(dev, pstate);
2768 		if (ret)
2769 			goto err;
2770 		dev_gpd_data(dev)->default_pstate = pstate;
2771 	}
2772 
2773 	if (power_on) {
2774 		genpd_lock(pd);
2775 		ret = genpd_power_on(pd, 0);
2776 		genpd_unlock(pd);
2777 	}
2778 
2779 	if (ret) {
2780 		/* Drop the default performance state */
2781 		if (dev_gpd_data(dev)->default_pstate) {
2782 			dev_pm_genpd_set_performance_state(dev, 0);
2783 			dev_gpd_data(dev)->default_pstate = 0;
2784 		}
2785 
2786 		genpd_remove_device(pd, dev);
2787 		return -EPROBE_DEFER;
2788 	}
2789 
2790 	return 1;
2791 
2792 err:
2793 	dev_err(dev, "failed to set required performance state for power-domain %s: %d\n",
2794 		pd->name, ret);
2795 	genpd_remove_device(pd, dev);
2796 	return ret;
2797 }
2798 
2799 /**
2800  * genpd_dev_pm_attach - Attach a device to its PM domain using DT.
2801  * @dev: Device to attach.
2802  *
2803  * Parse device's OF node to find a PM domain specifier. If such is found,
2804  * attaches the device to retrieved pm_domain ops.
2805  *
2806  * Returns 1 on successfully attached PM domain, 0 when the device don't need a
2807  * PM domain or when multiple power-domains exists for it, else a negative error
2808  * code. Note that if a power-domain exists for the device, but it cannot be
2809  * found or turned on, then return -EPROBE_DEFER to ensure that the device is
2810  * not probed and to re-try again later.
2811  */
2812 int genpd_dev_pm_attach(struct device *dev)
2813 {
2814 	if (!dev->of_node)
2815 		return 0;
2816 
2817 	/*
2818 	 * Devices with multiple PM domains must be attached separately, as we
2819 	 * can only attach one PM domain per device.
2820 	 */
2821 	if (of_count_phandle_with_args(dev->of_node, "power-domains",
2822 				       "#power-domain-cells") != 1)
2823 		return 0;
2824 
2825 	return __genpd_dev_pm_attach(dev, dev, 0, true);
2826 }
2827 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
2828 
2829 /**
2830  * genpd_dev_pm_attach_by_id - Associate a device with one of its PM domains.
2831  * @dev: The device used to lookup the PM domain.
2832  * @index: The index of the PM domain.
2833  *
2834  * Parse device's OF node to find a PM domain specifier at the provided @index.
2835  * If such is found, creates a virtual device and attaches it to the retrieved
2836  * pm_domain ops. To deal with detaching of the virtual device, the ->detach()
2837  * callback in the struct dev_pm_domain are assigned to genpd_dev_pm_detach().
2838  *
2839  * Returns the created virtual device if successfully attached PM domain, NULL
2840  * when the device don't need a PM domain, else an ERR_PTR() in case of
2841  * failures. If a power-domain exists for the device, but cannot be found or
2842  * turned on, then ERR_PTR(-EPROBE_DEFER) is returned to ensure that the device
2843  * is not probed and to re-try again later.
2844  */
2845 struct device *genpd_dev_pm_attach_by_id(struct device *dev,
2846 					 unsigned int index)
2847 {
2848 	struct device *virt_dev;
2849 	int num_domains;
2850 	int ret;
2851 
2852 	if (!dev->of_node)
2853 		return NULL;
2854 
2855 	/* Verify that the index is within a valid range. */
2856 	num_domains = of_count_phandle_with_args(dev->of_node, "power-domains",
2857 						 "#power-domain-cells");
2858 	if (index >= num_domains)
2859 		return NULL;
2860 
2861 	/* Allocate and register device on the genpd bus. */
2862 	virt_dev = kzalloc(sizeof(*virt_dev), GFP_KERNEL);
2863 	if (!virt_dev)
2864 		return ERR_PTR(-ENOMEM);
2865 
2866 	dev_set_name(virt_dev, "genpd:%u:%s", index, dev_name(dev));
2867 	virt_dev->bus = &genpd_bus_type;
2868 	virt_dev->release = genpd_release_dev;
2869 	virt_dev->of_node = of_node_get(dev->of_node);
2870 
2871 	ret = device_register(virt_dev);
2872 	if (ret) {
2873 		put_device(virt_dev);
2874 		return ERR_PTR(ret);
2875 	}
2876 
2877 	/* Try to attach the device to the PM domain at the specified index. */
2878 	ret = __genpd_dev_pm_attach(virt_dev, dev, index, false);
2879 	if (ret < 1) {
2880 		device_unregister(virt_dev);
2881 		return ret ? ERR_PTR(ret) : NULL;
2882 	}
2883 
2884 	pm_runtime_enable(virt_dev);
2885 	genpd_queue_power_off_work(dev_to_genpd(virt_dev));
2886 
2887 	return virt_dev;
2888 }
2889 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach_by_id);
2890 
2891 /**
2892  * genpd_dev_pm_attach_by_name - Associate a device with one of its PM domains.
2893  * @dev: The device used to lookup the PM domain.
2894  * @name: The name of the PM domain.
2895  *
2896  * Parse device's OF node to find a PM domain specifier using the
2897  * power-domain-names DT property. For further description see
2898  * genpd_dev_pm_attach_by_id().
2899  */
2900 struct device *genpd_dev_pm_attach_by_name(struct device *dev, const char *name)
2901 {
2902 	int index;
2903 
2904 	if (!dev->of_node)
2905 		return NULL;
2906 
2907 	index = of_property_match_string(dev->of_node, "power-domain-names",
2908 					 name);
2909 	if (index < 0)
2910 		return NULL;
2911 
2912 	return genpd_dev_pm_attach_by_id(dev, index);
2913 }
2914 
2915 static const struct of_device_id idle_state_match[] = {
2916 	{ .compatible = "domain-idle-state", },
2917 	{ }
2918 };
2919 
2920 static int genpd_parse_state(struct genpd_power_state *genpd_state,
2921 				    struct device_node *state_node)
2922 {
2923 	int err;
2924 	u32 residency;
2925 	u32 entry_latency, exit_latency;
2926 
2927 	err = of_property_read_u32(state_node, "entry-latency-us",
2928 						&entry_latency);
2929 	if (err) {
2930 		pr_debug(" * %pOF missing entry-latency-us property\n",
2931 			 state_node);
2932 		return -EINVAL;
2933 	}
2934 
2935 	err = of_property_read_u32(state_node, "exit-latency-us",
2936 						&exit_latency);
2937 	if (err) {
2938 		pr_debug(" * %pOF missing exit-latency-us property\n",
2939 			 state_node);
2940 		return -EINVAL;
2941 	}
2942 
2943 	err = of_property_read_u32(state_node, "min-residency-us", &residency);
2944 	if (!err)
2945 		genpd_state->residency_ns = 1000LL * residency;
2946 
2947 	genpd_state->power_on_latency_ns = 1000LL * exit_latency;
2948 	genpd_state->power_off_latency_ns = 1000LL * entry_latency;
2949 	genpd_state->fwnode = &state_node->fwnode;
2950 
2951 	return 0;
2952 }
2953 
2954 static int genpd_iterate_idle_states(struct device_node *dn,
2955 				     struct genpd_power_state *states)
2956 {
2957 	int ret;
2958 	struct of_phandle_iterator it;
2959 	struct device_node *np;
2960 	int i = 0;
2961 
2962 	ret = of_count_phandle_with_args(dn, "domain-idle-states", NULL);
2963 	if (ret <= 0)
2964 		return ret == -ENOENT ? 0 : ret;
2965 
2966 	/* Loop over the phandles until all the requested entry is found */
2967 	of_for_each_phandle(&it, ret, dn, "domain-idle-states", NULL, 0) {
2968 		np = it.node;
2969 		if (!of_match_node(idle_state_match, np))
2970 			continue;
2971 
2972 		if (!of_device_is_available(np))
2973 			continue;
2974 
2975 		if (states) {
2976 			ret = genpd_parse_state(&states[i], np);
2977 			if (ret) {
2978 				pr_err("Parsing idle state node %pOF failed with err %d\n",
2979 				       np, ret);
2980 				of_node_put(np);
2981 				return ret;
2982 			}
2983 		}
2984 		i++;
2985 	}
2986 
2987 	return i;
2988 }
2989 
2990 /**
2991  * of_genpd_parse_idle_states: Return array of idle states for the genpd.
2992  *
2993  * @dn: The genpd device node
2994  * @states: The pointer to which the state array will be saved.
2995  * @n: The count of elements in the array returned from this function.
2996  *
2997  * Returns the device states parsed from the OF node. The memory for the states
2998  * is allocated by this function and is the responsibility of the caller to
2999  * free the memory after use. If any or zero compatible domain idle states is
3000  * found it returns 0 and in case of errors, a negative error code is returned.
3001  */
3002 int of_genpd_parse_idle_states(struct device_node *dn,
3003 			struct genpd_power_state **states, int *n)
3004 {
3005 	struct genpd_power_state *st;
3006 	int ret;
3007 
3008 	ret = genpd_iterate_idle_states(dn, NULL);
3009 	if (ret < 0)
3010 		return ret;
3011 
3012 	if (!ret) {
3013 		*states = NULL;
3014 		*n = 0;
3015 		return 0;
3016 	}
3017 
3018 	st = kcalloc(ret, sizeof(*st), GFP_KERNEL);
3019 	if (!st)
3020 		return -ENOMEM;
3021 
3022 	ret = genpd_iterate_idle_states(dn, st);
3023 	if (ret <= 0) {
3024 		kfree(st);
3025 		return ret < 0 ? ret : -EINVAL;
3026 	}
3027 
3028 	*states = st;
3029 	*n = ret;
3030 
3031 	return 0;
3032 }
3033 EXPORT_SYMBOL_GPL(of_genpd_parse_idle_states);
3034 
3035 /**
3036  * pm_genpd_opp_to_performance_state - Gets performance state of the genpd from its OPP node.
3037  *
3038  * @genpd_dev: Genpd's device for which the performance-state needs to be found.
3039  * @opp: struct dev_pm_opp of the OPP for which we need to find performance
3040  *	state.
3041  *
3042  * Returns performance state encoded in the OPP of the genpd. This calls
3043  * platform specific genpd->opp_to_performance_state() callback to translate
3044  * power domain OPP to performance state.
3045  *
3046  * Returns performance state on success and 0 on failure.
3047  */
3048 unsigned int pm_genpd_opp_to_performance_state(struct device *genpd_dev,
3049 					       struct dev_pm_opp *opp)
3050 {
3051 	struct generic_pm_domain *genpd = NULL;
3052 	int state;
3053 
3054 	genpd = container_of(genpd_dev, struct generic_pm_domain, dev);
3055 
3056 	if (unlikely(!genpd->opp_to_performance_state))
3057 		return 0;
3058 
3059 	genpd_lock(genpd);
3060 	state = genpd->opp_to_performance_state(genpd, opp);
3061 	genpd_unlock(genpd);
3062 
3063 	return state;
3064 }
3065 EXPORT_SYMBOL_GPL(pm_genpd_opp_to_performance_state);
3066 
3067 static int __init genpd_bus_init(void)
3068 {
3069 	return bus_register(&genpd_bus_type);
3070 }
3071 core_initcall(genpd_bus_init);
3072 
3073 #endif /* CONFIG_PM_GENERIC_DOMAINS_OF */
3074 
3075 
3076 /***        debugfs support        ***/
3077 
3078 #ifdef CONFIG_DEBUG_FS
3079 /*
3080  * TODO: This function is a slightly modified version of rtpm_status_show
3081  * from sysfs.c, so generalize it.
3082  */
3083 static void rtpm_status_str(struct seq_file *s, struct device *dev)
3084 {
3085 	static const char * const status_lookup[] = {
3086 		[RPM_ACTIVE] = "active",
3087 		[RPM_RESUMING] = "resuming",
3088 		[RPM_SUSPENDED] = "suspended",
3089 		[RPM_SUSPENDING] = "suspending"
3090 	};
3091 	const char *p = "";
3092 
3093 	if (dev->power.runtime_error)
3094 		p = "error";
3095 	else if (dev->power.disable_depth)
3096 		p = "unsupported";
3097 	else if (dev->power.runtime_status < ARRAY_SIZE(status_lookup))
3098 		p = status_lookup[dev->power.runtime_status];
3099 	else
3100 		WARN_ON(1);
3101 
3102 	seq_printf(s, "%-25s  ", p);
3103 }
3104 
3105 static void perf_status_str(struct seq_file *s, struct device *dev)
3106 {
3107 	struct generic_pm_domain_data *gpd_data;
3108 
3109 	gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
3110 	seq_put_decimal_ull(s, "", gpd_data->performance_state);
3111 }
3112 
3113 static int genpd_summary_one(struct seq_file *s,
3114 			struct generic_pm_domain *genpd)
3115 {
3116 	static const char * const status_lookup[] = {
3117 		[GENPD_STATE_ON] = "on",
3118 		[GENPD_STATE_OFF] = "off"
3119 	};
3120 	struct pm_domain_data *pm_data;
3121 	const char *kobj_path;
3122 	struct gpd_link *link;
3123 	char state[16];
3124 	int ret;
3125 
3126 	ret = genpd_lock_interruptible(genpd);
3127 	if (ret)
3128 		return -ERESTARTSYS;
3129 
3130 	if (WARN_ON(genpd->status >= ARRAY_SIZE(status_lookup)))
3131 		goto exit;
3132 	if (!genpd_status_on(genpd))
3133 		snprintf(state, sizeof(state), "%s-%u",
3134 			 status_lookup[genpd->status], genpd->state_idx);
3135 	else
3136 		snprintf(state, sizeof(state), "%s",
3137 			 status_lookup[genpd->status]);
3138 	seq_printf(s, "%-30s  %-50s %u", genpd->name, state, genpd->performance_state);
3139 
3140 	/*
3141 	 * Modifications on the list require holding locks on both
3142 	 * parent and child, so we are safe.
3143 	 * Also genpd->name is immutable.
3144 	 */
3145 	list_for_each_entry(link, &genpd->parent_links, parent_node) {
3146 		if (list_is_first(&link->parent_node, &genpd->parent_links))
3147 			seq_printf(s, "\n%48s", " ");
3148 		seq_printf(s, "%s", link->child->name);
3149 		if (!list_is_last(&link->parent_node, &genpd->parent_links))
3150 			seq_puts(s, ", ");
3151 	}
3152 
3153 	list_for_each_entry(pm_data, &genpd->dev_list, list_node) {
3154 		kobj_path = kobject_get_path(&pm_data->dev->kobj,
3155 				genpd_is_irq_safe(genpd) ?
3156 				GFP_ATOMIC : GFP_KERNEL);
3157 		if (kobj_path == NULL)
3158 			continue;
3159 
3160 		seq_printf(s, "\n    %-50s  ", kobj_path);
3161 		rtpm_status_str(s, pm_data->dev);
3162 		perf_status_str(s, pm_data->dev);
3163 		kfree(kobj_path);
3164 	}
3165 
3166 	seq_puts(s, "\n");
3167 exit:
3168 	genpd_unlock(genpd);
3169 
3170 	return 0;
3171 }
3172 
3173 static int summary_show(struct seq_file *s, void *data)
3174 {
3175 	struct generic_pm_domain *genpd;
3176 	int ret = 0;
3177 
3178 	seq_puts(s, "domain                          status          children                           performance\n");
3179 	seq_puts(s, "    /device                                             runtime status\n");
3180 	seq_puts(s, "----------------------------------------------------------------------------------------------\n");
3181 
3182 	ret = mutex_lock_interruptible(&gpd_list_lock);
3183 	if (ret)
3184 		return -ERESTARTSYS;
3185 
3186 	list_for_each_entry(genpd, &gpd_list, gpd_list_node) {
3187 		ret = genpd_summary_one(s, genpd);
3188 		if (ret)
3189 			break;
3190 	}
3191 	mutex_unlock(&gpd_list_lock);
3192 
3193 	return ret;
3194 }
3195 
3196 static int status_show(struct seq_file *s, void *data)
3197 {
3198 	static const char * const status_lookup[] = {
3199 		[GENPD_STATE_ON] = "on",
3200 		[GENPD_STATE_OFF] = "off"
3201 	};
3202 
3203 	struct generic_pm_domain *genpd = s->private;
3204 	int ret = 0;
3205 
3206 	ret = genpd_lock_interruptible(genpd);
3207 	if (ret)
3208 		return -ERESTARTSYS;
3209 
3210 	if (WARN_ON_ONCE(genpd->status >= ARRAY_SIZE(status_lookup)))
3211 		goto exit;
3212 
3213 	if (genpd->status == GENPD_STATE_OFF)
3214 		seq_printf(s, "%s-%u\n", status_lookup[genpd->status],
3215 			genpd->state_idx);
3216 	else
3217 		seq_printf(s, "%s\n", status_lookup[genpd->status]);
3218 exit:
3219 	genpd_unlock(genpd);
3220 	return ret;
3221 }
3222 
3223 static int sub_domains_show(struct seq_file *s, void *data)
3224 {
3225 	struct generic_pm_domain *genpd = s->private;
3226 	struct gpd_link *link;
3227 	int ret = 0;
3228 
3229 	ret = genpd_lock_interruptible(genpd);
3230 	if (ret)
3231 		return -ERESTARTSYS;
3232 
3233 	list_for_each_entry(link, &genpd->parent_links, parent_node)
3234 		seq_printf(s, "%s\n", link->child->name);
3235 
3236 	genpd_unlock(genpd);
3237 	return ret;
3238 }
3239 
3240 static int idle_states_show(struct seq_file *s, void *data)
3241 {
3242 	struct generic_pm_domain *genpd = s->private;
3243 	u64 now, delta, idle_time = 0;
3244 	unsigned int i;
3245 	int ret = 0;
3246 
3247 	ret = genpd_lock_interruptible(genpd);
3248 	if (ret)
3249 		return -ERESTARTSYS;
3250 
3251 	seq_puts(s, "State          Time Spent(ms) Usage          Rejected\n");
3252 
3253 	for (i = 0; i < genpd->state_count; i++) {
3254 		idle_time += genpd->states[i].idle_time;
3255 
3256 		if (genpd->status == GENPD_STATE_OFF && genpd->state_idx == i) {
3257 			now = ktime_get_mono_fast_ns();
3258 			if (now > genpd->accounting_time) {
3259 				delta = now - genpd->accounting_time;
3260 				idle_time += delta;
3261 			}
3262 		}
3263 
3264 		do_div(idle_time, NSEC_PER_MSEC);
3265 		seq_printf(s, "S%-13i %-14llu %-14llu %llu\n", i, idle_time,
3266 			   genpd->states[i].usage, genpd->states[i].rejected);
3267 	}
3268 
3269 	genpd_unlock(genpd);
3270 	return ret;
3271 }
3272 
3273 static int active_time_show(struct seq_file *s, void *data)
3274 {
3275 	struct generic_pm_domain *genpd = s->private;
3276 	u64 now, on_time, delta = 0;
3277 	int ret = 0;
3278 
3279 	ret = genpd_lock_interruptible(genpd);
3280 	if (ret)
3281 		return -ERESTARTSYS;
3282 
3283 	if (genpd->status == GENPD_STATE_ON) {
3284 		now = ktime_get_mono_fast_ns();
3285 		if (now > genpd->accounting_time)
3286 			delta = now - genpd->accounting_time;
3287 	}
3288 
3289 	on_time = genpd->on_time + delta;
3290 	do_div(on_time, NSEC_PER_MSEC);
3291 	seq_printf(s, "%llu ms\n", on_time);
3292 
3293 	genpd_unlock(genpd);
3294 	return ret;
3295 }
3296 
3297 static int total_idle_time_show(struct seq_file *s, void *data)
3298 {
3299 	struct generic_pm_domain *genpd = s->private;
3300 	u64 now, delta, total = 0;
3301 	unsigned int i;
3302 	int ret = 0;
3303 
3304 	ret = genpd_lock_interruptible(genpd);
3305 	if (ret)
3306 		return -ERESTARTSYS;
3307 
3308 	for (i = 0; i < genpd->state_count; i++) {
3309 		total += genpd->states[i].idle_time;
3310 
3311 		if (genpd->status == GENPD_STATE_OFF && genpd->state_idx == i) {
3312 			now = ktime_get_mono_fast_ns();
3313 			if (now > genpd->accounting_time) {
3314 				delta = now - genpd->accounting_time;
3315 				total += delta;
3316 			}
3317 		}
3318 	}
3319 
3320 	do_div(total, NSEC_PER_MSEC);
3321 	seq_printf(s, "%llu ms\n", total);
3322 
3323 	genpd_unlock(genpd);
3324 	return ret;
3325 }
3326 
3327 
3328 static int devices_show(struct seq_file *s, void *data)
3329 {
3330 	struct generic_pm_domain *genpd = s->private;
3331 	struct pm_domain_data *pm_data;
3332 	const char *kobj_path;
3333 	int ret = 0;
3334 
3335 	ret = genpd_lock_interruptible(genpd);
3336 	if (ret)
3337 		return -ERESTARTSYS;
3338 
3339 	list_for_each_entry(pm_data, &genpd->dev_list, list_node) {
3340 		kobj_path = kobject_get_path(&pm_data->dev->kobj,
3341 				genpd_is_irq_safe(genpd) ?
3342 				GFP_ATOMIC : GFP_KERNEL);
3343 		if (kobj_path == NULL)
3344 			continue;
3345 
3346 		seq_printf(s, "%s\n", kobj_path);
3347 		kfree(kobj_path);
3348 	}
3349 
3350 	genpd_unlock(genpd);
3351 	return ret;
3352 }
3353 
3354 static int perf_state_show(struct seq_file *s, void *data)
3355 {
3356 	struct generic_pm_domain *genpd = s->private;
3357 
3358 	if (genpd_lock_interruptible(genpd))
3359 		return -ERESTARTSYS;
3360 
3361 	seq_printf(s, "%u\n", genpd->performance_state);
3362 
3363 	genpd_unlock(genpd);
3364 	return 0;
3365 }
3366 
3367 DEFINE_SHOW_ATTRIBUTE(summary);
3368 DEFINE_SHOW_ATTRIBUTE(status);
3369 DEFINE_SHOW_ATTRIBUTE(sub_domains);
3370 DEFINE_SHOW_ATTRIBUTE(idle_states);
3371 DEFINE_SHOW_ATTRIBUTE(active_time);
3372 DEFINE_SHOW_ATTRIBUTE(total_idle_time);
3373 DEFINE_SHOW_ATTRIBUTE(devices);
3374 DEFINE_SHOW_ATTRIBUTE(perf_state);
3375 
3376 static void genpd_debug_add(struct generic_pm_domain *genpd)
3377 {
3378 	struct dentry *d;
3379 
3380 	if (!genpd_debugfs_dir)
3381 		return;
3382 
3383 	d = debugfs_create_dir(genpd->name, genpd_debugfs_dir);
3384 
3385 	debugfs_create_file("current_state", 0444,
3386 			    d, genpd, &status_fops);
3387 	debugfs_create_file("sub_domains", 0444,
3388 			    d, genpd, &sub_domains_fops);
3389 	debugfs_create_file("idle_states", 0444,
3390 			    d, genpd, &idle_states_fops);
3391 	debugfs_create_file("active_time", 0444,
3392 			    d, genpd, &active_time_fops);
3393 	debugfs_create_file("total_idle_time", 0444,
3394 			    d, genpd, &total_idle_time_fops);
3395 	debugfs_create_file("devices", 0444,
3396 			    d, genpd, &devices_fops);
3397 	if (genpd->set_performance_state)
3398 		debugfs_create_file("perf_state", 0444,
3399 				    d, genpd, &perf_state_fops);
3400 }
3401 
3402 static int __init genpd_debug_init(void)
3403 {
3404 	struct generic_pm_domain *genpd;
3405 
3406 	genpd_debugfs_dir = debugfs_create_dir("pm_genpd", NULL);
3407 
3408 	debugfs_create_file("pm_genpd_summary", S_IRUGO, genpd_debugfs_dir,
3409 			    NULL, &summary_fops);
3410 
3411 	list_for_each_entry(genpd, &gpd_list, gpd_list_node)
3412 		genpd_debug_add(genpd);
3413 
3414 	return 0;
3415 }
3416 late_initcall(genpd_debug_init);
3417 
3418 static void __exit genpd_debug_exit(void)
3419 {
3420 	debugfs_remove_recursive(genpd_debugfs_dir);
3421 }
3422 __exitcall(genpd_debug_exit);
3423 #endif /* CONFIG_DEBUG_FS */
3424