1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * drivers/base/power/main.c - Where the driver meets power management.
   4 *
   5 * Copyright (c) 2003 Patrick Mochel
   6 * Copyright (c) 2003 Open Source Development Lab
   7 *
 
 
 
   8 * The driver model core calls device_pm_add() when a device is registered.
   9 * This will initialize the embedded device_pm_info object in the device
  10 * and add it to the list of power-controlled devices. sysfs entries for
  11 * controlling device power management will also be added.
  12 *
  13 * A separate list is used for keeping track of power info, because the power
  14 * domain dependencies may differ from the ancestral dependencies that the
  15 * subsystem list maintains.
  16 */
  17
  18#define pr_fmt(fmt) "PM: " fmt
  19#define dev_fmt pr_fmt
  20
  21#include <linux/device.h>
  22#include <linux/export.h>
  23#include <linux/mutex.h>
  24#include <linux/pm.h>
  25#include <linux/pm_runtime.h>
  26#include <linux/pm-trace.h>
  27#include <linux/pm_wakeirq.h>
  28#include <linux/interrupt.h>
  29#include <linux/sched.h>
  30#include <linux/sched/debug.h>
  31#include <linux/async.h>
  32#include <linux/suspend.h>
  33#include <trace/events/power.h>
  34#include <linux/cpufreq.h>
  35#include <linux/devfreq.h>
  36#include <linux/timer.h>
  37
  38#include "../base.h"
  39#include "power.h"
  40
  41typedef int (*pm_callback_t)(struct device *);
  42
  43#define list_for_each_entry_rcu_locked(pos, head, member) \
  44	list_for_each_entry_rcu(pos, head, member, \
  45			device_links_read_lock_held())
  46
  47/*
  48 * The entries in the dpm_list list are in a depth first order, simply
  49 * because children are guaranteed to be discovered after parents, and
  50 * are inserted at the back of the list on discovery.
  51 *
  52 * Since device_pm_add() may be called with a device lock held,
  53 * we must never try to acquire a device lock while holding
  54 * dpm_list_mutex.
  55 */
  56
  57LIST_HEAD(dpm_list);
  58static LIST_HEAD(dpm_prepared_list);
  59static LIST_HEAD(dpm_suspended_list);
  60static LIST_HEAD(dpm_late_early_list);
  61static LIST_HEAD(dpm_noirq_list);
  62
  63struct suspend_stats suspend_stats;
  64static DEFINE_MUTEX(dpm_list_mtx);
  65static pm_message_t pm_transition;
  66
  67static int async_error;
  68
  69static const char *pm_verb(int event)
  70{
  71	switch (event) {
  72	case PM_EVENT_SUSPEND:
  73		return "suspend";
  74	case PM_EVENT_RESUME:
  75		return "resume";
  76	case PM_EVENT_FREEZE:
  77		return "freeze";
  78	case PM_EVENT_QUIESCE:
  79		return "quiesce";
  80	case PM_EVENT_HIBERNATE:
  81		return "hibernate";
  82	case PM_EVENT_THAW:
  83		return "thaw";
  84	case PM_EVENT_RESTORE:
  85		return "restore";
  86	case PM_EVENT_RECOVER:
  87		return "recover";
  88	default:
  89		return "(unknown PM event)";
  90	}
  91}
  92
  93/**
  94 * device_pm_sleep_init - Initialize system suspend-related device fields.
  95 * @dev: Device object being initialized.
  96 */
  97void device_pm_sleep_init(struct device *dev)
  98{
  99	dev->power.is_prepared = false;
 100	dev->power.is_suspended = false;
 101	dev->power.is_noirq_suspended = false;
 102	dev->power.is_late_suspended = false;
 103	init_completion(&dev->power.completion);
 104	complete_all(&dev->power.completion);
 105	dev->power.wakeup = NULL;
 
 
 106	INIT_LIST_HEAD(&dev->power.entry);
 107}
 108
 109/**
 110 * device_pm_lock - Lock the list of active devices used by the PM core.
 111 */
 112void device_pm_lock(void)
 113{
 114	mutex_lock(&dpm_list_mtx);
 115}
 116
 117/**
 118 * device_pm_unlock - Unlock the list of active devices used by the PM core.
 119 */
 120void device_pm_unlock(void)
 121{
 122	mutex_unlock(&dpm_list_mtx);
 123}
 124
 125/**
 126 * device_pm_add - Add a device to the PM core's list of active devices.
 127 * @dev: Device to add to the list.
 128 */
 129void device_pm_add(struct device *dev)
 130{
 131	/* Skip PM setup/initialization. */
 132	if (device_pm_not_required(dev))
 133		return;
 134
 135	pr_debug("Adding info for %s:%s\n",
 136		 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 137	device_pm_check_callbacks(dev);
 138	mutex_lock(&dpm_list_mtx);
 139	if (dev->parent && dev->parent->power.is_prepared)
 140		dev_warn(dev, "parent %s should not be sleeping\n",
 141			dev_name(dev->parent));
 142	list_add_tail(&dev->power.entry, &dpm_list);
 143	dev->power.in_dpm_list = true;
 144	mutex_unlock(&dpm_list_mtx);
 145}
 146
 147/**
 148 * device_pm_remove - Remove a device from the PM core's list of active devices.
 149 * @dev: Device to be removed from the list.
 150 */
 151void device_pm_remove(struct device *dev)
 152{
 153	if (device_pm_not_required(dev))
 154		return;
 155
 156	pr_debug("Removing info for %s:%s\n",
 157		 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 158	complete_all(&dev->power.completion);
 159	mutex_lock(&dpm_list_mtx);
 160	list_del_init(&dev->power.entry);
 161	dev->power.in_dpm_list = false;
 162	mutex_unlock(&dpm_list_mtx);
 163	device_wakeup_disable(dev);
 164	pm_runtime_remove(dev);
 165	device_pm_check_callbacks(dev);
 166}
 167
 168/**
 169 * device_pm_move_before - Move device in the PM core's list of active devices.
 170 * @deva: Device to move in dpm_list.
 171 * @devb: Device @deva should come before.
 172 */
 173void device_pm_move_before(struct device *deva, struct device *devb)
 174{
 175	pr_debug("Moving %s:%s before %s:%s\n",
 176		 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 177		 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 178	/* Delete deva from dpm_list and reinsert before devb. */
 179	list_move_tail(&deva->power.entry, &devb->power.entry);
 180}
 181
 182/**
 183 * device_pm_move_after - Move device in the PM core's list of active devices.
 184 * @deva: Device to move in dpm_list.
 185 * @devb: Device @deva should come after.
 186 */
 187void device_pm_move_after(struct device *deva, struct device *devb)
 188{
 189	pr_debug("Moving %s:%s after %s:%s\n",
 190		 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 191		 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 192	/* Delete deva from dpm_list and reinsert after devb. */
 193	list_move(&deva->power.entry, &devb->power.entry);
 194}
 195
 196/**
 197 * device_pm_move_last - Move device to end of the PM core's list of devices.
 198 * @dev: Device to move in dpm_list.
 199 */
 200void device_pm_move_last(struct device *dev)
 201{
 202	pr_debug("Moving %s:%s to end of list\n",
 203		 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 204	list_move_tail(&dev->power.entry, &dpm_list);
 205}
 206
 207static ktime_t initcall_debug_start(struct device *dev, void *cb)
 208{
 209	if (!pm_print_times_enabled)
 210		return 0;
 211
 212	dev_info(dev, "calling %pS @ %i, parent: %s\n", cb,
 213		 task_pid_nr(current),
 214		 dev->parent ? dev_name(dev->parent) : "none");
 215	return ktime_get();
 
 
 
 216}
 217
 218static void initcall_debug_report(struct device *dev, ktime_t calltime,
 219				  void *cb, int error)
 220{
 221	ktime_t rettime;
 222
 223	if (!pm_print_times_enabled)
 224		return;
 225
 226	rettime = ktime_get();
 227	dev_info(dev, "%pS returned %d after %Ld usecs\n", cb, error,
 228		 (unsigned long long)ktime_us_delta(rettime, calltime));
 229}
 230
 231/**
 232 * dpm_wait - Wait for a PM operation to complete.
 233 * @dev: Device to wait for.
 234 * @async: If unset, wait only if the device's power.async_suspend flag is set.
 235 */
 236static void dpm_wait(struct device *dev, bool async)
 237{
 238	if (!dev)
 239		return;
 240
 241	if (async || (pm_async_enabled && dev->power.async_suspend))
 242		wait_for_completion(&dev->power.completion);
 243}
 244
 245static int dpm_wait_fn(struct device *dev, void *async_ptr)
 246{
 247	dpm_wait(dev, *((bool *)async_ptr));
 248	return 0;
 249}
 250
 251static void dpm_wait_for_children(struct device *dev, bool async)
 252{
 253       device_for_each_child(dev, &async, dpm_wait_fn);
 254}
 255
 256static void dpm_wait_for_suppliers(struct device *dev, bool async)
 257{
 258	struct device_link *link;
 259	int idx;
 260
 261	idx = device_links_read_lock();
 262
 263	/*
 264	 * If the supplier goes away right after we've checked the link to it,
 265	 * we'll wait for its completion to change the state, but that's fine,
 266	 * because the only things that will block as a result are the SRCU
 267	 * callbacks freeing the link objects for the links in the list we're
 268	 * walking.
 269	 */
 270	list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node)
 271		if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 272			dpm_wait(link->supplier, async);
 273
 274	device_links_read_unlock(idx);
 275}
 276
 277static bool dpm_wait_for_superior(struct device *dev, bool async)
 278{
 279	struct device *parent;
 280
 281	/*
 282	 * If the device is resumed asynchronously and the parent's callback
 283	 * deletes both the device and the parent itself, the parent object may
 284	 * be freed while this function is running, so avoid that by reference
 285	 * counting the parent once more unless the device has been deleted
 286	 * already (in which case return right away).
 287	 */
 288	mutex_lock(&dpm_list_mtx);
 289
 290	if (!device_pm_initialized(dev)) {
 291		mutex_unlock(&dpm_list_mtx);
 292		return false;
 293	}
 294
 295	parent = get_device(dev->parent);
 296
 297	mutex_unlock(&dpm_list_mtx);
 298
 299	dpm_wait(parent, async);
 300	put_device(parent);
 301
 302	dpm_wait_for_suppliers(dev, async);
 303
 304	/*
 305	 * If the parent's callback has deleted the device, attempting to resume
 306	 * it would be invalid, so avoid doing that then.
 307	 */
 308	return device_pm_initialized(dev);
 309}
 310
 311static void dpm_wait_for_consumers(struct device *dev, bool async)
 312{
 313	struct device_link *link;
 314	int idx;
 315
 316	idx = device_links_read_lock();
 317
 318	/*
 319	 * The status of a device link can only be changed from "dormant" by a
 320	 * probe, but that cannot happen during system suspend/resume.  In
 321	 * theory it can change to "dormant" at that time, but then it is
 322	 * reasonable to wait for the target device anyway (eg. if it goes
 323	 * away, it's better to wait for it to go away completely and then
 324	 * continue instead of trying to continue in parallel with its
 325	 * unregistration).
 326	 */
 327	list_for_each_entry_rcu_locked(link, &dev->links.consumers, s_node)
 328		if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 329			dpm_wait(link->consumer, async);
 330
 331	device_links_read_unlock(idx);
 332}
 333
 334static void dpm_wait_for_subordinate(struct device *dev, bool async)
 335{
 336	dpm_wait_for_children(dev, async);
 337	dpm_wait_for_consumers(dev, async);
 338}
 339
 340/**
 341 * pm_op - Return the PM operation appropriate for given PM event.
 
 342 * @ops: PM operations to choose from.
 343 * @state: PM transition of the system being carried out.
 344 */
 345static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
 
 
 346{
 
 
 
 
 
 347	switch (state.event) {
 348#ifdef CONFIG_SUSPEND
 349	case PM_EVENT_SUSPEND:
 350		return ops->suspend;
 
 
 
 
 351	case PM_EVENT_RESUME:
 352		return ops->resume;
 
 
 
 
 353#endif /* CONFIG_SUSPEND */
 354#ifdef CONFIG_HIBERNATE_CALLBACKS
 355	case PM_EVENT_FREEZE:
 356	case PM_EVENT_QUIESCE:
 357		return ops->freeze;
 
 
 
 
 358	case PM_EVENT_HIBERNATE:
 359		return ops->poweroff;
 
 
 
 
 360	case PM_EVENT_THAW:
 361	case PM_EVENT_RECOVER:
 362		return ops->thaw;
 
 
 
 
 363	case PM_EVENT_RESTORE:
 364		return ops->restore;
 
 
 
 
 365#endif /* CONFIG_HIBERNATE_CALLBACKS */
 
 
 366	}
 367
 368	return NULL;
 
 
 369}
 370
 371/**
 372 * pm_late_early_op - Return the PM operation appropriate for given PM event.
 
 373 * @ops: PM operations to choose from.
 374 * @state: PM transition of the system being carried out.
 375 *
 376 * Runtime PM is disabled for @dev while this function is being executed.
 
 377 */
 378static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
 379				      pm_message_t state)
 
 380{
 
 
 
 
 
 
 
 
 
 
 381	switch (state.event) {
 382#ifdef CONFIG_SUSPEND
 383	case PM_EVENT_SUSPEND:
 384		return ops->suspend_late;
 
 
 
 
 385	case PM_EVENT_RESUME:
 386		return ops->resume_early;
 
 
 
 
 387#endif /* CONFIG_SUSPEND */
 388#ifdef CONFIG_HIBERNATE_CALLBACKS
 389	case PM_EVENT_FREEZE:
 390	case PM_EVENT_QUIESCE:
 391		return ops->freeze_late;
 
 
 
 
 392	case PM_EVENT_HIBERNATE:
 393		return ops->poweroff_late;
 
 
 
 
 394	case PM_EVENT_THAW:
 395	case PM_EVENT_RECOVER:
 396		return ops->thaw_early;
 
 
 
 
 397	case PM_EVENT_RESTORE:
 398		return ops->restore_early;
 
 
 
 
 399#endif /* CONFIG_HIBERNATE_CALLBACKS */
 
 
 
 
 
 
 
 
 
 
 400	}
 401
 402	return NULL;
 403}
 404
 405/**
 406 * pm_noirq_op - Return the PM operation appropriate for given PM event.
 407 * @ops: PM operations to choose from.
 408 * @state: PM transition of the system being carried out.
 409 *
 410 * The driver of @dev will not receive interrupts while this function is being
 411 * executed.
 412 */
 413static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
 414{
 415	switch (state.event) {
 416#ifdef CONFIG_SUSPEND
 417	case PM_EVENT_SUSPEND:
 418		return ops->suspend_noirq;
 419	case PM_EVENT_RESUME:
 420		return ops->resume_noirq;
 421#endif /* CONFIG_SUSPEND */
 422#ifdef CONFIG_HIBERNATE_CALLBACKS
 423	case PM_EVENT_FREEZE:
 
 424	case PM_EVENT_QUIESCE:
 425		return ops->freeze_noirq;
 426	case PM_EVENT_HIBERNATE:
 427		return ops->poweroff_noirq;
 428	case PM_EVENT_THAW:
 429	case PM_EVENT_RECOVER:
 430		return ops->thaw_noirq;
 431	case PM_EVENT_RESTORE:
 432		return ops->restore_noirq;
 433#endif /* CONFIG_HIBERNATE_CALLBACKS */
 
 
 
 434	}
 435
 436	return NULL;
 437}
 438
 439static void pm_dev_dbg(struct device *dev, pm_message_t state, const char *info)
 440{
 441	dev_dbg(dev, "%s%s%s driver flags: %x\n", info, pm_verb(state.event),
 442		((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
 443		", may wakeup" : "", dev->power.driver_flags);
 444}
 445
 446static void pm_dev_err(struct device *dev, pm_message_t state, const char *info,
 447			int error)
 448{
 449	dev_err(dev, "failed to %s%s: error %d\n", pm_verb(state.event), info,
 450		error);
 451}
 452
 453static void dpm_show_time(ktime_t starttime, pm_message_t state, int error,
 454			  const char *info)
 455{
 456	ktime_t calltime;
 457	u64 usecs64;
 458	int usecs;
 459
 460	calltime = ktime_get();
 461	usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
 462	do_div(usecs64, NSEC_PER_USEC);
 463	usecs = usecs64;
 464	if (usecs == 0)
 465		usecs = 1;
 466
 467	pm_pr_dbg("%s%s%s of devices %s after %ld.%03ld msecs\n",
 468		  info ?: "", info ? " " : "", pm_verb(state.event),
 469		  error ? "aborted" : "complete",
 470		  usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
 471}
 472
 473static int dpm_run_callback(pm_callback_t cb, struct device *dev,
 474			    pm_message_t state, const char *info)
 475{
 476	ktime_t calltime;
 477	int error;
 478
 479	if (!cb)
 480		return 0;
 481
 482	calltime = initcall_debug_start(dev, cb);
 483
 484	pm_dev_dbg(dev, state, info);
 485	trace_device_pm_callback_start(dev, info, state.event);
 486	error = cb(dev);
 487	trace_device_pm_callback_end(dev, error);
 488	suspend_report_result(dev, cb, error);
 489
 490	initcall_debug_report(dev, calltime, cb, error);
 491
 492	return error;
 493}
 494
 495#ifdef CONFIG_DPM_WATCHDOG
 496struct dpm_watchdog {
 497	struct device		*dev;
 498	struct task_struct	*tsk;
 499	struct timer_list	timer;
 500};
 501
 502#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
 503	struct dpm_watchdog wd
 504
 505/**
 506 * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
 507 * @t: The timer that PM watchdog depends on.
 508 *
 509 * Called when a driver has timed out suspending or resuming.
 510 * There's not much we can do here to recover so panic() to
 511 * capture a crash-dump in pstore.
 512 */
 513static void dpm_watchdog_handler(struct timer_list *t)
 514{
 515	struct dpm_watchdog *wd = from_timer(wd, t, timer);
 516
 517	dev_emerg(wd->dev, "**** DPM device timeout ****\n");
 518	show_stack(wd->tsk, NULL, KERN_EMERG);
 519	panic("%s %s: unrecoverable failure\n",
 520		dev_driver_string(wd->dev), dev_name(wd->dev));
 521}
 522
 523/**
 524 * dpm_watchdog_set - Enable pm watchdog for given device.
 525 * @wd: Watchdog. Must be allocated on the stack.
 526 * @dev: Device to handle.
 527 */
 528static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
 529{
 530	struct timer_list *timer = &wd->timer;
 531
 532	wd->dev = dev;
 533	wd->tsk = current;
 534
 535	timer_setup_on_stack(timer, dpm_watchdog_handler, 0);
 536	/* use same timeout value for both suspend and resume */
 537	timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
 538	add_timer(timer);
 539}
 540
 541/**
 542 * dpm_watchdog_clear - Disable suspend/resume watchdog.
 543 * @wd: Watchdog to disable.
 544 */
 545static void dpm_watchdog_clear(struct dpm_watchdog *wd)
 546{
 547	struct timer_list *timer = &wd->timer;
 548
 549	del_timer_sync(timer);
 550	destroy_timer_on_stack(timer);
 551}
 552#else
 553#define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
 554#define dpm_watchdog_set(x, y)
 555#define dpm_watchdog_clear(x)
 556#endif
 557
 558/*------------------------- Resume routines -------------------------*/
 559
 560/**
 561 * dev_pm_skip_resume - System-wide device resume optimization check.
 562 * @dev: Target device.
 563 *
 564 * Return:
 565 * - %false if the transition under way is RESTORE.
 566 * - Return value of dev_pm_skip_suspend() if the transition under way is THAW.
 567 * - The logical negation of %power.must_resume otherwise (that is, when the
 568 *   transition under way is RESUME).
 569 */
 570bool dev_pm_skip_resume(struct device *dev)
 571{
 572	if (pm_transition.event == PM_EVENT_RESTORE)
 573		return false;
 574
 575	if (pm_transition.event == PM_EVENT_THAW)
 576		return dev_pm_skip_suspend(dev);
 577
 578	return !dev->power.must_resume;
 579}
 580
 581/**
 582 * device_resume_noirq - Execute a "noirq resume" callback for given device.
 583 * @dev: Device to handle.
 584 * @state: PM transition of the system being carried out.
 585 * @async: If true, the device is being resumed asynchronously.
 586 *
 587 * The driver of @dev will not receive interrupts while this function is being
 588 * executed.
 589 */
 590static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
 591{
 592	pm_callback_t callback = NULL;
 593	const char *info = NULL;
 594	bool skip_resume;
 595	int error = 0;
 596
 597	TRACE_DEVICE(dev);
 598	TRACE_RESUME(0);
 599
 600	if (dev->power.syscore || dev->power.direct_complete)
 601		goto Out;
 602
 603	if (!dev->power.is_noirq_suspended)
 604		goto Out;
 605
 606	if (!dpm_wait_for_superior(dev, async))
 607		goto Out;
 608
 609	skip_resume = dev_pm_skip_resume(dev);
 610	/*
 611	 * If the driver callback is skipped below or by the middle layer
 612	 * callback and device_resume_early() also skips the driver callback for
 613	 * this device later, it needs to appear as "suspended" to PM-runtime,
 614	 * so change its status accordingly.
 615	 *
 616	 * Otherwise, the device is going to be resumed, so set its PM-runtime
 617	 * status to "active", but do that only if DPM_FLAG_SMART_SUSPEND is set
 618	 * to avoid confusing drivers that don't use it.
 619	 */
 620	if (skip_resume)
 621		pm_runtime_set_suspended(dev);
 622	else if (dev_pm_skip_suspend(dev))
 623		pm_runtime_set_active(dev);
 624
 625	if (dev->pm_domain) {
 626		info = "noirq power domain ";
 627		callback = pm_noirq_op(&dev->pm_domain->ops, state);
 628	} else if (dev->type && dev->type->pm) {
 629		info = "noirq type ";
 630		callback = pm_noirq_op(dev->type->pm, state);
 631	} else if (dev->class && dev->class->pm) {
 632		info = "noirq class ";
 633		callback = pm_noirq_op(dev->class->pm, state);
 634	} else if (dev->bus && dev->bus->pm) {
 635		info = "noirq bus ";
 636		callback = pm_noirq_op(dev->bus->pm, state);
 637	}
 638	if (callback)
 639		goto Run;
 640
 641	if (skip_resume)
 642		goto Skip;
 643
 644	if (dev->driver && dev->driver->pm) {
 645		info = "noirq driver ";
 646		callback = pm_noirq_op(dev->driver->pm, state);
 647	}
 648
 649Run:
 650	error = dpm_run_callback(callback, dev, state, info);
 651
 652Skip:
 653	dev->power.is_noirq_suspended = false;
 654
 655Out:
 656	complete_all(&dev->power.completion);
 657	TRACE_RESUME(error);
 658	return error;
 659}
 660
 661static bool is_async(struct device *dev)
 662{
 663	return dev->power.async_suspend && pm_async_enabled
 664		&& !pm_trace_is_enabled();
 665}
 666
 667static bool dpm_async_fn(struct device *dev, async_func_t func)
 668{
 669	reinit_completion(&dev->power.completion);
 670
 671	if (is_async(dev)) {
 672		get_device(dev);
 673		async_schedule_dev(func, dev);
 674		return true;
 675	}
 676
 677	return false;
 678}
 679
 680static void async_resume_noirq(void *data, async_cookie_t cookie)
 681{
 682	struct device *dev = (struct device *)data;
 683	int error;
 684
 685	error = device_resume_noirq(dev, pm_transition, true);
 686	if (error)
 687		pm_dev_err(dev, pm_transition, " async", error);
 688
 689	put_device(dev);
 690}
 691
 692static void dpm_noirq_resume_devices(pm_message_t state)
 693{
 694	struct device *dev;
 695	ktime_t starttime = ktime_get();
 696
 697	trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
 698	mutex_lock(&dpm_list_mtx);
 699	pm_transition = state;
 700
 701	/*
 702	 * Advanced the async threads upfront,
 703	 * in case the starting of async threads is
 704	 * delayed by non-async resuming devices.
 705	 */
 706	list_for_each_entry(dev, &dpm_noirq_list, power.entry)
 707		dpm_async_fn(dev, async_resume_noirq);
 708
 709	while (!list_empty(&dpm_noirq_list)) {
 710		dev = to_device(dpm_noirq_list.next);
 711		get_device(dev);
 712		list_move_tail(&dev->power.entry, &dpm_late_early_list);
 713
 714		mutex_unlock(&dpm_list_mtx);
 715
 716		if (!is_async(dev)) {
 717			int error;
 718
 719			error = device_resume_noirq(dev, state, false);
 720			if (error) {
 721				suspend_stats.failed_resume_noirq++;
 722				dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
 723				dpm_save_failed_dev(dev_name(dev));
 724				pm_dev_err(dev, state, " noirq", error);
 725			}
 726		}
 727
 728		put_device(dev);
 729
 730		mutex_lock(&dpm_list_mtx);
 731	}
 732	mutex_unlock(&dpm_list_mtx);
 733	async_synchronize_full();
 734	dpm_show_time(starttime, state, 0, "noirq");
 735	trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
 736}
 737
 738/**
 739 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
 740 * @state: PM transition of the system being carried out.
 741 *
 742 * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
 743 * allow device drivers' interrupt handlers to be called.
 744 */
 745void dpm_resume_noirq(pm_message_t state)
 746{
 747	dpm_noirq_resume_devices(state);
 748
 749	resume_device_irqs();
 750	device_wakeup_disarm_wake_irqs();
 751}
 752
 753/**
 754 * device_resume_early - Execute an "early resume" callback for given device.
 755 * @dev: Device to handle.
 756 * @state: PM transition of the system being carried out.
 757 * @async: If true, the device is being resumed asynchronously.
 758 *
 759 * Runtime PM is disabled for @dev while this function is being executed.
 760 */
 761static int device_resume_early(struct device *dev, pm_message_t state, bool async)
 762{
 763	pm_callback_t callback = NULL;
 764	const char *info = NULL;
 765	int error = 0;
 766
 767	TRACE_DEVICE(dev);
 768	TRACE_RESUME(0);
 769
 770	if (dev->power.syscore || dev->power.direct_complete)
 771		goto Out;
 772
 773	if (!dev->power.is_late_suspended)
 774		goto Out;
 775
 776	if (!dpm_wait_for_superior(dev, async))
 777		goto Out;
 778
 779	if (dev->pm_domain) {
 780		info = "early power domain ";
 781		callback = pm_late_early_op(&dev->pm_domain->ops, state);
 782	} else if (dev->type && dev->type->pm) {
 783		info = "early type ";
 784		callback = pm_late_early_op(dev->type->pm, state);
 785	} else if (dev->class && dev->class->pm) {
 786		info = "early class ";
 787		callback = pm_late_early_op(dev->class->pm, state);
 788	} else if (dev->bus && dev->bus->pm) {
 789		info = "early bus ";
 790		callback = pm_late_early_op(dev->bus->pm, state);
 791	}
 792	if (callback)
 793		goto Run;
 794
 795	if (dev_pm_skip_resume(dev))
 796		goto Skip;
 797
 798	if (dev->driver && dev->driver->pm) {
 799		info = "early driver ";
 800		callback = pm_late_early_op(dev->driver->pm, state);
 801	}
 802
 803Run:
 804	error = dpm_run_callback(callback, dev, state, info);
 805
 806Skip:
 807	dev->power.is_late_suspended = false;
 808
 809Out:
 810	TRACE_RESUME(error);
 811
 812	pm_runtime_enable(dev);
 813	complete_all(&dev->power.completion);
 814	return error;
 815}
 816
 817static void async_resume_early(void *data, async_cookie_t cookie)
 818{
 819	struct device *dev = (struct device *)data;
 820	int error;
 821
 822	error = device_resume_early(dev, pm_transition, true);
 823	if (error)
 824		pm_dev_err(dev, pm_transition, " async", error);
 825
 826	put_device(dev);
 827}
 828
 829/**
 830 * dpm_resume_early - Execute "early resume" callbacks for all devices.
 831 * @state: PM transition of the system being carried out.
 832 */
 833void dpm_resume_early(pm_message_t state)
 834{
 835	struct device *dev;
 836	ktime_t starttime = ktime_get();
 837
 838	trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
 839	mutex_lock(&dpm_list_mtx);
 840	pm_transition = state;
 841
 842	/*
 843	 * Advanced the async threads upfront,
 844	 * in case the starting of async threads is
 845	 * delayed by non-async resuming devices.
 846	 */
 847	list_for_each_entry(dev, &dpm_late_early_list, power.entry)
 848		dpm_async_fn(dev, async_resume_early);
 849
 850	while (!list_empty(&dpm_late_early_list)) {
 851		dev = to_device(dpm_late_early_list.next);
 852		get_device(dev);
 853		list_move_tail(&dev->power.entry, &dpm_suspended_list);
 854
 855		mutex_unlock(&dpm_list_mtx);
 856
 857		if (!is_async(dev)) {
 858			int error;
 859
 860			error = device_resume_early(dev, state, false);
 861			if (error) {
 862				suspend_stats.failed_resume_early++;
 863				dpm_save_failed_step(SUSPEND_RESUME_EARLY);
 864				dpm_save_failed_dev(dev_name(dev));
 865				pm_dev_err(dev, state, " early", error);
 866			}
 867		}
 868
 869		put_device(dev);
 870
 871		mutex_lock(&dpm_list_mtx);
 
 872	}
 873	mutex_unlock(&dpm_list_mtx);
 874	async_synchronize_full();
 875	dpm_show_time(starttime, state, 0, "early");
 876	trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
 877}
 
 878
 879/**
 880 * dpm_resume_start - Execute "noirq" and "early" device callbacks.
 881 * @state: PM transition of the system being carried out.
 
 882 */
 883void dpm_resume_start(pm_message_t state)
 884{
 885	dpm_resume_noirq(state);
 886	dpm_resume_early(state);
 
 
 
 
 
 
 
 
 
 887}
 888EXPORT_SYMBOL_GPL(dpm_resume_start);
 889
 890/**
 891 * device_resume - Execute "resume" callbacks for given device.
 892 * @dev: Device to handle.
 893 * @state: PM transition of the system being carried out.
 894 * @async: If true, the device is being resumed asynchronously.
 895 */
 896static int device_resume(struct device *dev, pm_message_t state, bool async)
 897{
 898	pm_callback_t callback = NULL;
 899	const char *info = NULL;
 900	int error = 0;
 901	DECLARE_DPM_WATCHDOG_ON_STACK(wd);
 902
 903	TRACE_DEVICE(dev);
 904	TRACE_RESUME(0);
 905
 906	if (dev->power.syscore)
 907		goto Complete;
 908
 909	if (dev->power.direct_complete) {
 910		/* Match the pm_runtime_disable() in __device_suspend(). */
 911		pm_runtime_enable(dev);
 912		goto Complete;
 913	}
 914
 915	if (!dpm_wait_for_superior(dev, async))
 916		goto Complete;
 917
 918	dpm_watchdog_set(&wd, dev);
 919	device_lock(dev);
 920
 921	/*
 922	 * This is a fib.  But we'll allow new children to be added below
 923	 * a resumed device, even if the device hasn't been completed yet.
 924	 */
 925	dev->power.is_prepared = false;
 926
 927	if (!dev->power.is_suspended)
 928		goto Unlock;
 929
 
 
 
 930	if (dev->pm_domain) {
 931		info = "power domain ";
 932		callback = pm_op(&dev->pm_domain->ops, state);
 933		goto Driver;
 934	}
 935
 936	if (dev->type && dev->type->pm) {
 937		info = "type ";
 938		callback = pm_op(dev->type->pm, state);
 939		goto Driver;
 940	}
 941
 942	if (dev->class && dev->class->pm) {
 943		info = "class ";
 944		callback = pm_op(dev->class->pm, state);
 945		goto Driver;
 
 
 
 
 
 
 946	}
 947
 948	if (dev->bus) {
 949		if (dev->bus->pm) {
 950			info = "bus ";
 951			callback = pm_op(dev->bus->pm, state);
 952		} else if (dev->bus->resume) {
 953			info = "legacy bus ";
 954			callback = dev->bus->resume;
 955			goto End;
 956		}
 957	}
 958
 959 Driver:
 960	if (!callback && dev->driver && dev->driver->pm) {
 961		info = "driver ";
 962		callback = pm_op(dev->driver->pm, state);
 963	}
 964
 965 End:
 966	error = dpm_run_callback(callback, dev, state, info);
 967	dev->power.is_suspended = false;
 968
 969 Unlock:
 970	device_unlock(dev);
 971	dpm_watchdog_clear(&wd);
 972
 973 Complete:
 974	complete_all(&dev->power.completion);
 975
 976	TRACE_RESUME(error);
 977
 
 
 
 978	return error;
 979}
 980
 981static void async_resume(void *data, async_cookie_t cookie)
 982{
 983	struct device *dev = (struct device *)data;
 984	int error;
 985
 986	error = device_resume(dev, pm_transition, true);
 987	if (error)
 988		pm_dev_err(dev, pm_transition, " async", error);
 989	put_device(dev);
 990}
 991
 
 
 
 
 
 
 992/**
 993 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
 994 * @state: PM transition of the system being carried out.
 995 *
 996 * Execute the appropriate "resume" callback for all devices whose status
 997 * indicates that they are suspended.
 998 */
 999void dpm_resume(pm_message_t state)
1000{
1001	struct device *dev;
1002	ktime_t starttime = ktime_get();
1003
1004	trace_suspend_resume(TPS("dpm_resume"), state.event, true);
1005	might_sleep();
1006
1007	mutex_lock(&dpm_list_mtx);
1008	pm_transition = state;
1009	async_error = 0;
1010
1011	list_for_each_entry(dev, &dpm_suspended_list, power.entry)
1012		dpm_async_fn(dev, async_resume);
 
 
 
 
 
1013
1014	while (!list_empty(&dpm_suspended_list)) {
1015		dev = to_device(dpm_suspended_list.next);
1016		get_device(dev);
1017		if (!is_async(dev)) {
1018			int error;
1019
1020			mutex_unlock(&dpm_list_mtx);
1021
1022			error = device_resume(dev, state, false);
1023			if (error) {
1024				suspend_stats.failed_resume++;
1025				dpm_save_failed_step(SUSPEND_RESUME);
1026				dpm_save_failed_dev(dev_name(dev));
1027				pm_dev_err(dev, state, "", error);
1028			}
1029
1030			mutex_lock(&dpm_list_mtx);
1031		}
1032		if (!list_empty(&dev->power.entry))
1033			list_move_tail(&dev->power.entry, &dpm_prepared_list);
1034
1035		mutex_unlock(&dpm_list_mtx);
1036
1037		put_device(dev);
1038
1039		mutex_lock(&dpm_list_mtx);
1040	}
1041	mutex_unlock(&dpm_list_mtx);
1042	async_synchronize_full();
1043	dpm_show_time(starttime, state, 0, NULL);
1044
1045	cpufreq_resume();
1046	devfreq_resume();
1047	trace_suspend_resume(TPS("dpm_resume"), state.event, false);
1048}
1049
1050/**
1051 * device_complete - Complete a PM transition for given device.
1052 * @dev: Device to handle.
1053 * @state: PM transition of the system being carried out.
1054 */
1055static void device_complete(struct device *dev, pm_message_t state)
1056{
1057	void (*callback)(struct device *) = NULL;
1058	const char *info = NULL;
1059
1060	if (dev->power.syscore)
1061		goto out;
1062
1063	device_lock(dev);
1064
1065	if (dev->pm_domain) {
1066		info = "completing power domain ";
1067		callback = dev->pm_domain->ops.complete;
 
1068	} else if (dev->type && dev->type->pm) {
1069		info = "completing type ";
1070		callback = dev->type->pm->complete;
 
1071	} else if (dev->class && dev->class->pm) {
1072		info = "completing class ";
1073		callback = dev->class->pm->complete;
 
1074	} else if (dev->bus && dev->bus->pm) {
1075		info = "completing bus ";
1076		callback = dev->bus->pm->complete;
1077	}
1078
1079	if (!callback && dev->driver && dev->driver->pm) {
1080		info = "completing driver ";
1081		callback = dev->driver->pm->complete;
1082	}
1083
1084	if (callback) {
1085		pm_dev_dbg(dev, state, info);
1086		callback(dev);
1087	}
1088
1089	device_unlock(dev);
1090
1091out:
1092	pm_runtime_put(dev);
1093}
1094
1095/**
1096 * dpm_complete - Complete a PM transition for all non-sysdev devices.
1097 * @state: PM transition of the system being carried out.
1098 *
1099 * Execute the ->complete() callbacks for all devices whose PM status is not
1100 * DPM_ON (this allows new devices to be registered).
1101 */
1102void dpm_complete(pm_message_t state)
1103{
1104	struct list_head list;
1105
1106	trace_suspend_resume(TPS("dpm_complete"), state.event, true);
1107	might_sleep();
1108
1109	INIT_LIST_HEAD(&list);
1110	mutex_lock(&dpm_list_mtx);
1111	while (!list_empty(&dpm_prepared_list)) {
1112		struct device *dev = to_device(dpm_prepared_list.prev);
1113
1114		get_device(dev);
1115		dev->power.is_prepared = false;
1116		list_move(&dev->power.entry, &list);
1117
1118		mutex_unlock(&dpm_list_mtx);
1119
1120		trace_device_pm_callback_start(dev, "", state.event);
1121		device_complete(dev, state);
1122		trace_device_pm_callback_end(dev, 0);
1123
1124		put_device(dev);
1125
1126		mutex_lock(&dpm_list_mtx);
 
1127	}
1128	list_splice(&list, &dpm_list);
1129	mutex_unlock(&dpm_list_mtx);
1130
1131	/* Allow device probing and trigger re-probing of deferred devices */
1132	device_unblock_probing();
1133	trace_suspend_resume(TPS("dpm_complete"), state.event, false);
1134}
1135
1136/**
1137 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1138 * @state: PM transition of the system being carried out.
1139 *
1140 * Execute "resume" callbacks for all devices and complete the PM transition of
1141 * the system.
1142 */
1143void dpm_resume_end(pm_message_t state)
1144{
1145	dpm_resume(state);
1146	dpm_complete(state);
1147}
1148EXPORT_SYMBOL_GPL(dpm_resume_end);
1149
1150
1151/*------------------------- Suspend routines -------------------------*/
1152
1153/**
1154 * resume_event - Return a "resume" message for given "suspend" sleep state.
1155 * @sleep_state: PM message representing a sleep state.
1156 *
1157 * Return a PM message representing the resume event corresponding to given
1158 * sleep state.
1159 */
1160static pm_message_t resume_event(pm_message_t sleep_state)
1161{
1162	switch (sleep_state.event) {
1163	case PM_EVENT_SUSPEND:
1164		return PMSG_RESUME;
1165	case PM_EVENT_FREEZE:
1166	case PM_EVENT_QUIESCE:
1167		return PMSG_RECOVER;
1168	case PM_EVENT_HIBERNATE:
1169		return PMSG_RESTORE;
1170	}
1171	return PMSG_ON;
1172}
1173
1174static void dpm_superior_set_must_resume(struct device *dev)
1175{
1176	struct device_link *link;
1177	int idx;
1178
1179	if (dev->parent)
1180		dev->parent->power.must_resume = true;
1181
1182	idx = device_links_read_lock();
1183
1184	list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node)
1185		link->supplier->power.must_resume = true;
1186
1187	device_links_read_unlock(idx);
1188}
1189
1190/**
1191 * __device_suspend_noirq - Execute a "noirq suspend" callback for given device.
1192 * @dev: Device to handle.
1193 * @state: PM transition of the system being carried out.
1194 * @async: If true, the device is being suspended asynchronously.
1195 *
1196 * The driver of @dev will not receive interrupts while this function is being
1197 * executed.
1198 */
1199static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1200{
1201	pm_callback_t callback = NULL;
1202	const char *info = NULL;
1203	int error = 0;
1204
1205	TRACE_DEVICE(dev);
1206	TRACE_SUSPEND(0);
1207
1208	dpm_wait_for_subordinate(dev, async);
1209
1210	if (async_error)
1211		goto Complete;
1212
1213	if (dev->power.syscore || dev->power.direct_complete)
1214		goto Complete;
1215
1216	if (dev->pm_domain) {
1217		info = "noirq power domain ";
1218		callback = pm_noirq_op(&dev->pm_domain->ops, state);
 
 
1219	} else if (dev->type && dev->type->pm) {
1220		info = "noirq type ";
1221		callback = pm_noirq_op(dev->type->pm, state);
 
 
1222	} else if (dev->class && dev->class->pm) {
1223		info = "noirq class ";
1224		callback = pm_noirq_op(dev->class->pm, state);
 
 
1225	} else if (dev->bus && dev->bus->pm) {
1226		info = "noirq bus ";
1227		callback = pm_noirq_op(dev->bus->pm, state);
1228	}
1229	if (callback)
1230		goto Run;
1231
1232	if (dev_pm_skip_suspend(dev))
1233		goto Skip;
1234
1235	if (dev->driver && dev->driver->pm) {
1236		info = "noirq driver ";
1237		callback = pm_noirq_op(dev->driver->pm, state);
1238	}
1239
1240Run:
1241	error = dpm_run_callback(callback, dev, state, info);
1242	if (error) {
1243		async_error = error;
1244		goto Complete;
1245	}
1246
1247Skip:
1248	dev->power.is_noirq_suspended = true;
1249
1250	/*
1251	 * Skipping the resume of devices that were in use right before the
1252	 * system suspend (as indicated by their PM-runtime usage counters)
1253	 * would be suboptimal.  Also resume them if doing that is not allowed
1254	 * to be skipped.
1255	 */
1256	if (atomic_read(&dev->power.usage_count) > 1 ||
1257	    !(dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME) &&
1258	      dev->power.may_skip_resume))
1259		dev->power.must_resume = true;
1260
1261	if (dev->power.must_resume)
1262		dpm_superior_set_must_resume(dev);
1263
1264Complete:
1265	complete_all(&dev->power.completion);
1266	TRACE_SUSPEND(error);
1267	return error;
1268}
1269
1270static void async_suspend_noirq(void *data, async_cookie_t cookie)
1271{
1272	struct device *dev = (struct device *)data;
1273	int error;
1274
1275	error = __device_suspend_noirq(dev, pm_transition, true);
1276	if (error) {
1277		dpm_save_failed_dev(dev_name(dev));
1278		pm_dev_err(dev, pm_transition, " async", error);
1279	}
1280
1281	put_device(dev);
1282}
1283
1284static int device_suspend_noirq(struct device *dev)
1285{
1286	if (dpm_async_fn(dev, async_suspend_noirq))
1287		return 0;
1288
1289	return __device_suspend_noirq(dev, pm_transition, false);
1290}
1291
1292static int dpm_noirq_suspend_devices(pm_message_t state)
1293{
1294	ktime_t starttime = ktime_get();
1295	int error = 0;
1296
1297	trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1298	mutex_lock(&dpm_list_mtx);
1299	pm_transition = state;
1300	async_error = 0;
1301
1302	while (!list_empty(&dpm_late_early_list)) {
1303		struct device *dev = to_device(dpm_late_early_list.prev);
1304
1305		get_device(dev);
1306		mutex_unlock(&dpm_list_mtx);
1307
1308		error = device_suspend_noirq(dev);
1309
1310		mutex_lock(&dpm_list_mtx);
1311
1312		if (error) {
1313			pm_dev_err(dev, state, " noirq", error);
1314			dpm_save_failed_dev(dev_name(dev));
1315		} else if (!list_empty(&dev->power.entry)) {
1316			list_move(&dev->power.entry, &dpm_noirq_list);
1317		}
1318
1319		mutex_unlock(&dpm_list_mtx);
1320
1321		put_device(dev);
1322
1323		mutex_lock(&dpm_list_mtx);
1324
1325		if (error || async_error)
1326			break;
1327	}
1328	mutex_unlock(&dpm_list_mtx);
1329	async_synchronize_full();
1330	if (!error)
1331		error = async_error;
1332
1333	if (error) {
1334		suspend_stats.failed_suspend_noirq++;
1335		dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1336	}
1337	dpm_show_time(starttime, state, error, "noirq");
1338	trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1339	return error;
1340}
1341
1342/**
1343 * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1344 * @state: PM transition of the system being carried out.
1345 *
1346 * Prevent device drivers' interrupt handlers from being called and invoke
1347 * "noirq" suspend callbacks for all non-sysdev devices.
1348 */
1349int dpm_suspend_noirq(pm_message_t state)
1350{
1351	int ret;
1352
1353	device_wakeup_arm_wake_irqs();
1354	suspend_device_irqs();
1355
1356	ret = dpm_noirq_suspend_devices(state);
1357	if (ret)
1358		dpm_resume_noirq(resume_event(state));
1359
1360	return ret;
1361}
1362
1363static void dpm_propagate_wakeup_to_parent(struct device *dev)
1364{
1365	struct device *parent = dev->parent;
1366
1367	if (!parent)
1368		return;
1369
1370	spin_lock_irq(&parent->power.lock);
1371
1372	if (device_wakeup_path(dev) && !parent->power.ignore_children)
1373		parent->power.wakeup_path = true;
1374
1375	spin_unlock_irq(&parent->power.lock);
1376}
1377
1378/**
1379 * __device_suspend_late - Execute a "late suspend" callback for given device.
1380 * @dev: Device to handle.
1381 * @state: PM transition of the system being carried out.
1382 * @async: If true, the device is being suspended asynchronously.
1383 *
1384 * Runtime PM is disabled for @dev while this function is being executed.
1385 */
1386static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1387{
1388	pm_callback_t callback = NULL;
1389	const char *info = NULL;
1390	int error = 0;
1391
1392	TRACE_DEVICE(dev);
1393	TRACE_SUSPEND(0);
1394
1395	__pm_runtime_disable(dev, false);
1396
1397	dpm_wait_for_subordinate(dev, async);
1398
1399	if (async_error)
1400		goto Complete;
1401
1402	if (pm_wakeup_pending()) {
1403		async_error = -EBUSY;
1404		goto Complete;
1405	}
1406
1407	if (dev->power.syscore || dev->power.direct_complete)
1408		goto Complete;
1409
1410	if (dev->pm_domain) {
1411		info = "late power domain ";
1412		callback = pm_late_early_op(&dev->pm_domain->ops, state);
1413	} else if (dev->type && dev->type->pm) {
1414		info = "late type ";
1415		callback = pm_late_early_op(dev->type->pm, state);
1416	} else if (dev->class && dev->class->pm) {
1417		info = "late class ";
1418		callback = pm_late_early_op(dev->class->pm, state);
1419	} else if (dev->bus && dev->bus->pm) {
1420		info = "late bus ";
1421		callback = pm_late_early_op(dev->bus->pm, state);
1422	}
1423	if (callback)
1424		goto Run;
1425
1426	if (dev_pm_skip_suspend(dev))
1427		goto Skip;
1428
1429	if (dev->driver && dev->driver->pm) {
1430		info = "late driver ";
1431		callback = pm_late_early_op(dev->driver->pm, state);
1432	}
1433
1434Run:
1435	error = dpm_run_callback(callback, dev, state, info);
1436	if (error) {
1437		async_error = error;
1438		goto Complete;
1439	}
1440	dpm_propagate_wakeup_to_parent(dev);
1441
1442Skip:
1443	dev->power.is_late_suspended = true;
1444
1445Complete:
1446	TRACE_SUSPEND(error);
1447	complete_all(&dev->power.completion);
1448	return error;
1449}
1450
1451static void async_suspend_late(void *data, async_cookie_t cookie)
1452{
1453	struct device *dev = (struct device *)data;
1454	int error;
1455
1456	error = __device_suspend_late(dev, pm_transition, true);
1457	if (error) {
1458		dpm_save_failed_dev(dev_name(dev));
1459		pm_dev_err(dev, pm_transition, " async", error);
1460	}
1461	put_device(dev);
1462}
1463
1464static int device_suspend_late(struct device *dev)
1465{
1466	if (dpm_async_fn(dev, async_suspend_late))
1467		return 0;
1468
1469	return __device_suspend_late(dev, pm_transition, false);
1470}
1471
1472/**
1473 * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1474 * @state: PM transition of the system being carried out.
1475 */
1476int dpm_suspend_late(pm_message_t state)
1477{
1478	ktime_t starttime = ktime_get();
1479	int error = 0;
1480
1481	trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1482	wake_up_all_idle_cpus();
1483	mutex_lock(&dpm_list_mtx);
1484	pm_transition = state;
1485	async_error = 0;
1486
1487	while (!list_empty(&dpm_suspended_list)) {
1488		struct device *dev = to_device(dpm_suspended_list.prev);
1489
1490		get_device(dev);
1491
1492		mutex_unlock(&dpm_list_mtx);
1493
1494		error = device_suspend_late(dev);
1495
1496		mutex_lock(&dpm_list_mtx);
1497
1498		if (!list_empty(&dev->power.entry))
1499			list_move(&dev->power.entry, &dpm_late_early_list);
1500
1501		if (error) {
1502			pm_dev_err(dev, state, " late", error);
1503			dpm_save_failed_dev(dev_name(dev));
 
1504		}
1505
1506		mutex_unlock(&dpm_list_mtx);
1507
1508		put_device(dev);
1509
1510		mutex_lock(&dpm_list_mtx);
1511
1512		if (error || async_error)
1513			break;
1514	}
1515	mutex_unlock(&dpm_list_mtx);
1516	async_synchronize_full();
1517	if (!error)
1518		error = async_error;
1519	if (error) {
1520		suspend_stats.failed_suspend_late++;
1521		dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1522		dpm_resume_early(resume_event(state));
1523	}
1524	dpm_show_time(starttime, state, error, "late");
1525	trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1526	return error;
1527}
1528
1529/**
1530 * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1531 * @state: PM transition of the system being carried out.
1532 */
1533int dpm_suspend_end(pm_message_t state)
1534{
1535	ktime_t starttime = ktime_get();
1536	int error;
1537
1538	error = dpm_suspend_late(state);
1539	if (error)
1540		goto out;
1541
1542	error = dpm_suspend_noirq(state);
1543	if (error)
1544		dpm_resume_early(resume_event(state));
1545
1546out:
1547	dpm_show_time(starttime, state, error, "end");
1548	return error;
1549}
1550EXPORT_SYMBOL_GPL(dpm_suspend_end);
1551
1552/**
1553 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1554 * @dev: Device to suspend.
1555 * @state: PM transition of the system being carried out.
1556 * @cb: Suspend callback to execute.
1557 * @info: string description of caller.
1558 */
1559static int legacy_suspend(struct device *dev, pm_message_t state,
1560			  int (*cb)(struct device *dev, pm_message_t state),
1561			  const char *info)
1562{
1563	int error;
1564	ktime_t calltime;
1565
1566	calltime = initcall_debug_start(dev, cb);
1567
1568	trace_device_pm_callback_start(dev, info, state.event);
1569	error = cb(dev, state);
1570	trace_device_pm_callback_end(dev, error);
1571	suspend_report_result(dev, cb, error);
1572
1573	initcall_debug_report(dev, calltime, cb, error);
1574
1575	return error;
1576}
1577
1578static void dpm_clear_superiors_direct_complete(struct device *dev)
1579{
1580	struct device_link *link;
1581	int idx;
1582
1583	if (dev->parent) {
1584		spin_lock_irq(&dev->parent->power.lock);
1585		dev->parent->power.direct_complete = false;
1586		spin_unlock_irq(&dev->parent->power.lock);
1587	}
1588
1589	idx = device_links_read_lock();
1590
1591	list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node) {
1592		spin_lock_irq(&link->supplier->power.lock);
1593		link->supplier->power.direct_complete = false;
1594		spin_unlock_irq(&link->supplier->power.lock);
1595	}
1596
1597	device_links_read_unlock(idx);
1598}
1599
1600/**
1601 * __device_suspend - Execute "suspend" callbacks for given device.
1602 * @dev: Device to handle.
1603 * @state: PM transition of the system being carried out.
1604 * @async: If true, the device is being suspended asynchronously.
1605 */
1606static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1607{
1608	pm_callback_t callback = NULL;
1609	const char *info = NULL;
1610	int error = 0;
1611	DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1612
1613	TRACE_DEVICE(dev);
1614	TRACE_SUSPEND(0);
1615
1616	dpm_wait_for_subordinate(dev, async);
1617
1618	if (async_error) {
1619		dev->power.direct_complete = false;
1620		goto Complete;
1621	}
1622
1623	/*
1624	 * Wait for possible runtime PM transitions of the device in progress
1625	 * to complete and if there's a runtime resume request pending for it,
1626	 * resume it before proceeding with invoking the system-wide suspend
1627	 * callbacks for it.
1628	 *
1629	 * If the system-wide suspend callbacks below change the configuration
1630	 * of the device, they must disable runtime PM for it or otherwise
1631	 * ensure that its runtime-resume callbacks will not be confused by that
1632	 * change in case they are invoked going forward.
1633	 */
1634	pm_runtime_barrier(dev);
1635
1636	if (pm_wakeup_pending()) {
1637		dev->power.direct_complete = false;
1638		async_error = -EBUSY;
1639		goto Complete;
1640	}
1641
1642	if (dev->power.syscore)
1643		goto Complete;
1644
1645	/* Avoid direct_complete to let wakeup_path propagate. */
1646	if (device_may_wakeup(dev) || device_wakeup_path(dev))
1647		dev->power.direct_complete = false;
1648
1649	if (dev->power.direct_complete) {
1650		if (pm_runtime_status_suspended(dev)) {
1651			pm_runtime_disable(dev);
1652			if (pm_runtime_status_suspended(dev)) {
1653				pm_dev_dbg(dev, state, "direct-complete ");
1654				goto Complete;
1655			}
1656
1657			pm_runtime_enable(dev);
1658		}
1659		dev->power.direct_complete = false;
1660	}
1661
1662	dev->power.may_skip_resume = true;
1663	dev->power.must_resume = !dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME);
1664
1665	dpm_watchdog_set(&wd, dev);
1666	device_lock(dev);
1667
1668	if (dev->pm_domain) {
1669		info = "power domain ";
1670		callback = pm_op(&dev->pm_domain->ops, state);
1671		goto Run;
1672	}
1673
1674	if (dev->type && dev->type->pm) {
1675		info = "type ";
1676		callback = pm_op(dev->type->pm, state);
1677		goto Run;
1678	}
1679
1680	if (dev->class && dev->class->pm) {
1681		info = "class ";
1682		callback = pm_op(dev->class->pm, state);
1683		goto Run;
 
 
 
 
 
 
1684	}
1685
1686	if (dev->bus) {
1687		if (dev->bus->pm) {
1688			info = "bus ";
1689			callback = pm_op(dev->bus->pm, state);
1690		} else if (dev->bus->suspend) {
1691			pm_dev_dbg(dev, state, "legacy bus ");
1692			error = legacy_suspend(dev, state, dev->bus->suspend,
1693						"legacy bus ");
1694			goto End;
1695		}
1696	}
1697
1698 Run:
1699	if (!callback && dev->driver && dev->driver->pm) {
1700		info = "driver ";
1701		callback = pm_op(dev->driver->pm, state);
1702	}
1703
1704	error = dpm_run_callback(callback, dev, state, info);
1705
1706 End:
1707	if (!error) {
1708		dev->power.is_suspended = true;
1709		if (device_may_wakeup(dev))
1710			dev->power.wakeup_path = true;
1711
1712		dpm_propagate_wakeup_to_parent(dev);
1713		dpm_clear_superiors_direct_complete(dev);
1714	}
1715
1716	device_unlock(dev);
1717	dpm_watchdog_clear(&wd);
1718
1719 Complete:
1720	if (error)
1721		async_error = error;
 
 
 
1722
1723	complete_all(&dev->power.completion);
1724	TRACE_SUSPEND(error);
1725	return error;
1726}
1727
1728static void async_suspend(void *data, async_cookie_t cookie)
1729{
1730	struct device *dev = (struct device *)data;
1731	int error;
1732
1733	error = __device_suspend(dev, pm_transition, true);
1734	if (error) {
1735		dpm_save_failed_dev(dev_name(dev));
1736		pm_dev_err(dev, pm_transition, " async", error);
1737	}
1738
1739	put_device(dev);
1740}
1741
1742static int device_suspend(struct device *dev)
1743{
1744	if (dpm_async_fn(dev, async_suspend))
 
 
 
 
1745		return 0;
 
1746
1747	return __device_suspend(dev, pm_transition, false);
1748}
1749
1750/**
1751 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1752 * @state: PM transition of the system being carried out.
1753 */
1754int dpm_suspend(pm_message_t state)
1755{
1756	ktime_t starttime = ktime_get();
1757	int error = 0;
1758
1759	trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1760	might_sleep();
1761
1762	devfreq_suspend();
1763	cpufreq_suspend();
1764
1765	mutex_lock(&dpm_list_mtx);
1766	pm_transition = state;
1767	async_error = 0;
1768	while (!list_empty(&dpm_prepared_list)) {
1769		struct device *dev = to_device(dpm_prepared_list.prev);
1770
1771		get_device(dev);
1772
1773		mutex_unlock(&dpm_list_mtx);
1774
1775		error = device_suspend(dev);
1776
1777		mutex_lock(&dpm_list_mtx);
1778
1779		if (error) {
1780			pm_dev_err(dev, state, "", error);
1781			dpm_save_failed_dev(dev_name(dev));
1782		} else if (!list_empty(&dev->power.entry)) {
1783			list_move(&dev->power.entry, &dpm_suspended_list);
1784		}
1785
1786		mutex_unlock(&dpm_list_mtx);
1787
1788		put_device(dev);
1789
1790		mutex_lock(&dpm_list_mtx);
1791
1792		if (error || async_error)
1793			break;
1794	}
1795	mutex_unlock(&dpm_list_mtx);
1796	async_synchronize_full();
1797	if (!error)
1798		error = async_error;
1799	if (error) {
1800		suspend_stats.failed_suspend++;
1801		dpm_save_failed_step(SUSPEND_SUSPEND);
1802	}
1803	dpm_show_time(starttime, state, error, NULL);
1804	trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1805	return error;
1806}
1807
1808/**
1809 * device_prepare - Prepare a device for system power transition.
1810 * @dev: Device to handle.
1811 * @state: PM transition of the system being carried out.
1812 *
1813 * Execute the ->prepare() callback(s) for given device.  No new children of the
1814 * device may be registered after this function has returned.
1815 */
1816static int device_prepare(struct device *dev, pm_message_t state)
1817{
1818	int (*callback)(struct device *) = NULL;
1819	int ret = 0;
1820
1821	/*
1822	 * If a device's parent goes into runtime suspend at the wrong time,
1823	 * it won't be possible to resume the device.  To prevent this we
1824	 * block runtime suspend here, during the prepare phase, and allow
1825	 * it again during the complete phase.
1826	 */
1827	pm_runtime_get_noresume(dev);
1828
1829	if (dev->power.syscore)
1830		return 0;
1831
1832	device_lock(dev);
1833
1834	dev->power.wakeup_path = false;
1835
1836	if (dev->power.no_pm_callbacks)
1837		goto unlock;
1838
1839	if (dev->pm_domain)
1840		callback = dev->pm_domain->ops.prepare;
1841	else if (dev->type && dev->type->pm)
1842		callback = dev->type->pm->prepare;
1843	else if (dev->class && dev->class->pm)
1844		callback = dev->class->pm->prepare;
1845	else if (dev->bus && dev->bus->pm)
1846		callback = dev->bus->pm->prepare;
1847
1848	if (!callback && dev->driver && dev->driver->pm)
1849		callback = dev->driver->pm->prepare;
1850
1851	if (callback)
1852		ret = callback(dev);
 
 
 
 
 
 
 
 
1853
1854unlock:
1855	device_unlock(dev);
1856
1857	if (ret < 0) {
1858		suspend_report_result(dev, callback, ret);
1859		pm_runtime_put(dev);
1860		return ret;
1861	}
1862	/*
1863	 * A positive return value from ->prepare() means "this device appears
1864	 * to be runtime-suspended and its state is fine, so if it really is
1865	 * runtime-suspended, you can leave it in that state provided that you
1866	 * will do the same thing with all of its descendants".  This only
1867	 * applies to suspend transitions, however.
1868	 */
1869	spin_lock_irq(&dev->power.lock);
1870	dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
1871		(ret > 0 || dev->power.no_pm_callbacks) &&
1872		!dev_pm_test_driver_flags(dev, DPM_FLAG_NO_DIRECT_COMPLETE);
1873	spin_unlock_irq(&dev->power.lock);
1874	return 0;
1875}
1876
1877/**
1878 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1879 * @state: PM transition of the system being carried out.
1880 *
1881 * Execute the ->prepare() callback(s) for all devices.
1882 */
1883int dpm_prepare(pm_message_t state)
1884{
1885	int error = 0;
1886
1887	trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1888	might_sleep();
1889
1890	/*
1891	 * Give a chance for the known devices to complete their probes, before
1892	 * disable probing of devices. This sync point is important at least
1893	 * at boot time + hibernation restore.
1894	 */
1895	wait_for_device_probe();
1896	/*
1897	 * It is unsafe if probing of devices will happen during suspend or
1898	 * hibernation and system behavior will be unpredictable in this case.
1899	 * So, let's prohibit device's probing here and defer their probes
1900	 * instead. The normal behavior will be restored in dpm_complete().
1901	 */
1902	device_block_probing();
1903
1904	mutex_lock(&dpm_list_mtx);
1905	while (!list_empty(&dpm_list) && !error) {
1906		struct device *dev = to_device(dpm_list.next);
1907
1908		get_device(dev);
1909
1910		mutex_unlock(&dpm_list_mtx);
1911
1912		trace_device_pm_callback_start(dev, "", state.event);
1913		error = device_prepare(dev, state);
1914		trace_device_pm_callback_end(dev, error);
1915
1916		mutex_lock(&dpm_list_mtx);
1917
1918		if (!error) {
1919			dev->power.is_prepared = true;
1920			if (!list_empty(&dev->power.entry))
1921				list_move_tail(&dev->power.entry, &dpm_prepared_list);
1922		} else if (error == -EAGAIN) {
1923			error = 0;
1924		} else {
1925			dev_info(dev, "not prepared for power transition: code %d\n",
1926				 error);
 
1927		}
1928
1929		mutex_unlock(&dpm_list_mtx);
1930
1931		put_device(dev);
1932
1933		mutex_lock(&dpm_list_mtx);
1934	}
1935	mutex_unlock(&dpm_list_mtx);
1936	trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
1937	return error;
1938}
1939
1940/**
1941 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1942 * @state: PM transition of the system being carried out.
1943 *
1944 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1945 * callbacks for them.
1946 */
1947int dpm_suspend_start(pm_message_t state)
1948{
1949	ktime_t starttime = ktime_get();
1950	int error;
1951
1952	error = dpm_prepare(state);
1953	if (error) {
1954		suspend_stats.failed_prepare++;
1955		dpm_save_failed_step(SUSPEND_PREPARE);
1956	} else
1957		error = dpm_suspend(state);
1958	dpm_show_time(starttime, state, error, "start");
1959	return error;
1960}
1961EXPORT_SYMBOL_GPL(dpm_suspend_start);
1962
1963void __suspend_report_result(const char *function, struct device *dev, void *fn, int ret)
1964{
1965	if (ret)
1966		dev_err(dev, "%s(): %pS returns %d\n", function, fn, ret);
1967}
1968EXPORT_SYMBOL_GPL(__suspend_report_result);
1969
1970/**
1971 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1972 * @subordinate: Device that needs to wait for @dev.
1973 * @dev: Device to wait for.
 
1974 */
1975int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1976{
1977	dpm_wait(dev, subordinate->power.async_suspend);
1978	return async_error;
1979}
1980EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1981
1982/**
1983 * dpm_for_each_dev - device iterator.
1984 * @data: data for the callback.
1985 * @fn: function to be called for each device.
1986 *
1987 * Iterate over devices in dpm_list, and call @fn for each device,
1988 * passing it @data.
1989 */
1990void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
1991{
1992	struct device *dev;
1993
1994	if (!fn)
1995		return;
1996
1997	device_pm_lock();
1998	list_for_each_entry(dev, &dpm_list, power.entry)
1999		fn(dev, data);
2000	device_pm_unlock();
2001}
2002EXPORT_SYMBOL_GPL(dpm_for_each_dev);
2003
2004static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
2005{
2006	if (!ops)
2007		return true;
2008
2009	return !ops->prepare &&
2010	       !ops->suspend &&
2011	       !ops->suspend_late &&
2012	       !ops->suspend_noirq &&
2013	       !ops->resume_noirq &&
2014	       !ops->resume_early &&
2015	       !ops->resume &&
2016	       !ops->complete;
2017}
2018
2019void device_pm_check_callbacks(struct device *dev)
2020{
2021	unsigned long flags;
2022
2023	spin_lock_irqsave(&dev->power.lock, flags);
2024	dev->power.no_pm_callbacks =
2025		(!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
2026		 !dev->bus->suspend && !dev->bus->resume)) &&
2027		(!dev->class || pm_ops_is_empty(dev->class->pm)) &&
2028		(!dev->type || pm_ops_is_empty(dev->type->pm)) &&
2029		(!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
2030		(!dev->driver || (pm_ops_is_empty(dev->driver->pm) &&
2031		 !dev->driver->suspend && !dev->driver->resume));
2032	spin_unlock_irqrestore(&dev->power.lock, flags);
2033}
2034
2035bool dev_pm_skip_suspend(struct device *dev)
2036{
2037	return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
2038		pm_runtime_status_suspended(dev);
2039}