drivers/base/power/main.c

   1 /*
   2  * drivers/base/power/main.c - Where the driver meets power management.
   3  *
   4  * Copyright (c) 2003 Patrick Mochel
   5  * Copyright (c) 2003 Open Source Development Lab
   6  *
   7  * This file is released under the GPLv2
   8  *
   9  *
  10  * The driver model core calls device_pm_add() when a device is registered.
  11  * This will initialize the embedded device_pm_info object in the device
  12  * and add it to the list of power-controlled devices. sysfs entries for
  13  * controlling device power management will also be added.
  14  *
  15  * A separate list is used for keeping track of power info, because the power
  16  * domain dependencies may differ from the ancestral dependencies that the
  17  * subsystem list maintains.
  18  */
  19
  20 #include <linux/device.h>
  21 #include <linux/kallsyms.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/cpuidle.h>
  36 #include <linux/timer.h>
  37
  38 #include "../base.h"
  39 #include "power.h"
  40
  41 typedef int (*pm_callback_t)(struct device *);
  42
  43 /*
  44  * The entries in the dpm_list list are in a depth first order, simply
  45  * because children are guaranteed to be discovered after parents, and
  46  * are inserted at the back of the list on discovery.
  47  *
  48  * Since device_pm_add() may be called with a device lock held,
  49  * we must never try to acquire a device lock while holding
  50  * dpm_list_mutex.
  51  */
  52
  53 LIST_HEAD(dpm_list);
  54 static LIST_HEAD(dpm_prepared_list);
  55 static LIST_HEAD(dpm_suspended_list);
  56 static LIST_HEAD(dpm_late_early_list);
  57 static LIST_HEAD(dpm_noirq_list);
  58
  59 struct suspend_stats suspend_stats;
  60 static DEFINE_MUTEX(dpm_list_mtx);
  61 static pm_message_t pm_transition;
  62
  63 static int async_error;
  64
  65 static const char *pm_verb(int event)
  66 {
  67         switch (event) {
  68         case PM_EVENT_SUSPEND:
  69                 return "suspend";
  70         case PM_EVENT_RESUME:
  71                 return "resume";
  72         case PM_EVENT_FREEZE:
  73                 return "freeze";
  74         case PM_EVENT_QUIESCE:
  75                 return "quiesce";
  76         case PM_EVENT_HIBERNATE:
  77                 return "hibernate";
  78         case PM_EVENT_THAW:
  79                 return "thaw";
  80         case PM_EVENT_RESTORE:
  81                 return "restore";
  82         case PM_EVENT_RECOVER:
  83                 return "recover";
  84         default:
  85                 return "(unknown PM event)";
  86         }
  87 }
  88
  89 /**
  90  * device_pm_sleep_init - Initialize system suspend-related device fields.
  91  * @dev: Device object being initialized.
  92  */
  93 void device_pm_sleep_init(struct device *dev)
  94 {
  95         dev->power.is_prepared = false;
  96         dev->power.is_suspended = false;
  97         dev->power.is_noirq_suspended = false;
  98         dev->power.is_late_suspended = false;
  99         init_completion(&dev->power.completion);
 100         complete_all(&dev->power.completion);
 101         dev->power.wakeup = NULL;
 102         INIT_LIST_HEAD(&dev->power.entry);
 103 }
 104
 105 /**
 106  * device_pm_lock - Lock the list of active devices used by the PM core.
 107  */
 108 void device_pm_lock(void)
 109 {
 110         mutex_lock(&dpm_list_mtx);
 111 }
 112
 113 /**
 114  * device_pm_unlock - Unlock the list of active devices used by the PM core.
 115  */
 116 void device_pm_unlock(void)
 117 {
 118         mutex_unlock(&dpm_list_mtx);
 119 }
 120
 121 /**
 122  * device_pm_add - Add a device to the PM core's list of active devices.
 123  * @dev: Device to add to the list.
 124  */
 125 void device_pm_add(struct device *dev)
 126 {
 127         pr_debug("PM: Adding info for %s:%s\n",
 128                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 129         device_pm_check_callbacks(dev);
 130         mutex_lock(&dpm_list_mtx);
 131         if (dev->parent && dev->parent->power.is_prepared)
 132                 dev_warn(dev, "parent %s should not be sleeping\n",
 133                         dev_name(dev->parent));
 134         list_add_tail(&dev->power.entry, &dpm_list);
 135         dev->power.in_dpm_list = true;
 136         mutex_unlock(&dpm_list_mtx);
 137 }
 138
 139 /**
 140  * device_pm_remove - Remove a device from the PM core's list of active devices.
 141  * @dev: Device to be removed from the list.
 142  */
 143 void device_pm_remove(struct device *dev)
 144 {
 145         pr_debug("PM: Removing info for %s:%s\n",
 146                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 147         complete_all(&dev->power.completion);
 148         mutex_lock(&dpm_list_mtx);
 149         list_del_init(&dev->power.entry);
 150         dev->power.in_dpm_list = false;
 151         mutex_unlock(&dpm_list_mtx);
 152         device_wakeup_disable(dev);
 153         pm_runtime_remove(dev);
 154         device_pm_check_callbacks(dev);
 155 }
 156
 157 /**
 158  * device_pm_move_before - Move device in the PM core's list of active devices.
 159  * @deva: Device to move in dpm_list.
 160  * @devb: Device @deva should come before.
 161  */
 162 void device_pm_move_before(struct device *deva, struct device *devb)
 163 {
 164         pr_debug("PM: Moving %s:%s before %s:%s\n",
 165                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 166                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 167         /* Delete deva from dpm_list and reinsert before devb. */
 168         list_move_tail(&deva->power.entry, &devb->power.entry);
 169 }
 170
 171 /**
 172  * device_pm_move_after - Move device in the PM core's list of active devices.
 173  * @deva: Device to move in dpm_list.
 174  * @devb: Device @deva should come after.
 175  */
 176 void device_pm_move_after(struct device *deva, struct device *devb)
 177 {
 178         pr_debug("PM: Moving %s:%s after %s:%s\n",
 179                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 180                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 181         /* Delete deva from dpm_list and reinsert after devb. */
 182         list_move(&deva->power.entry, &devb->power.entry);
 183 }
 184
 185 /**
 186  * device_pm_move_last - Move device to end of the PM core's list of devices.
 187  * @dev: Device to move in dpm_list.
 188  */
 189 void device_pm_move_last(struct device *dev)
 190 {
 191         pr_debug("PM: Moving %s:%s to end of list\n",
 192                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 193         list_move_tail(&dev->power.entry, &dpm_list);
 194 }
 195
 196 static ktime_t initcall_debug_start(struct device *dev)
 197 {
 198         ktime_t calltime = 0;
 199
 200         if (pm_print_times_enabled) {
 201                 pr_info("calling  %s+ @ %i, parent: %s\n",
 202                         dev_name(dev), task_pid_nr(current),
 203                         dev->parent ? dev_name(dev->parent) : "none");
 204                 calltime = ktime_get();
 205         }
 206
 207         return calltime;
 208 }
 209
 210 static void initcall_debug_report(struct device *dev, ktime_t calltime,
 211                                   int error, pm_message_t state,
 212                                   const char *info)
 213 {
 214         ktime_t rettime;
 215         s64 nsecs;
 216
 217         rettime = ktime_get();
 218         nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime));
 219
 220         if (pm_print_times_enabled) {
 221                 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
 222                         error, (unsigned long long)nsecs >> 10);
 223         }
 224 }
 225
 226 /**
 227  * dpm_wait - Wait for a PM operation to complete.
 228  * @dev: Device to wait for.
 229  * @async: If unset, wait only if the device's power.async_suspend flag is set.
 230  */
 231 static void dpm_wait(struct device *dev, bool async)
 232 {
 233         if (!dev)
 234                 return;
 235
 236         if (async || (pm_async_enabled && dev->power.async_suspend))
 237                 wait_for_completion(&dev->power.completion);
 238 }
 239
 240 static int dpm_wait_fn(struct device *dev, void *async_ptr)
 241 {
 242         dpm_wait(dev, *((bool *)async_ptr));
 243         return 0;
 244 }
 245
 246 static void dpm_wait_for_children(struct device *dev, bool async)
 247 {
 248        device_for_each_child(dev, &async, dpm_wait_fn);
 249 }
 250
 251 static void dpm_wait_for_suppliers(struct device *dev, bool async)
 252 {
 253         struct device_link *link;
 254         int idx;
 255
 256         idx = device_links_read_lock();
 257
 258         /*
 259          * If the supplier goes away right after we've checked the link to it,
 260          * we'll wait for its completion to change the state, but that's fine,
 261          * because the only things that will block as a result are the SRCU
 262          * callbacks freeing the link objects for the links in the list we're
 263          * walking.
 264          */
 265         list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
 266                 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 267                         dpm_wait(link->supplier, async);
 268
 269         device_links_read_unlock(idx);
 270 }
 271
 272 static void dpm_wait_for_superior(struct device *dev, bool async)
 273 {
 274         dpm_wait(dev->parent, async);
 275         dpm_wait_for_suppliers(dev, async);
 276 }
 277
 278 static void dpm_wait_for_consumers(struct device *dev, bool async)
 279 {
 280         struct device_link *link;
 281         int idx;
 282
 283         idx = device_links_read_lock();
 284
 285         /*
 286          * The status of a device link can only be changed from "dormant" by a
 287          * probe, but that cannot happen during system suspend/resume.  In
 288          * theory it can change to "dormant" at that time, but then it is
 289          * reasonable to wait for the target device anyway (eg. if it goes
 290          * away, it's better to wait for it to go away completely and then
 291          * continue instead of trying to continue in parallel with its
 292          * unregistration).
 293          */
 294         list_for_each_entry_rcu(link, &dev->links.consumers, s_node)
 295                 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 296                         dpm_wait(link->consumer, async);
 297
 298         device_links_read_unlock(idx);
 299 }
 300
 301 static void dpm_wait_for_subordinate(struct device *dev, bool async)
 302 {
 303         dpm_wait_for_children(dev, async);
 304         dpm_wait_for_consumers(dev, async);
 305 }
 306
 307 /**
 308  * pm_op - Return the PM operation appropriate for given PM event.
 309  * @ops: PM operations to choose from.
 310  * @state: PM transition of the system being carried out.
 311  */
 312 static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
 313 {
 314         switch (state.event) {
 315 #ifdef CONFIG_SUSPEND
 316         case PM_EVENT_SUSPEND:
 317                 return ops->suspend;
 318         case PM_EVENT_RESUME:
 319                 return ops->resume;
 320 #endif /* CONFIG_SUSPEND */
 321 #ifdef CONFIG_HIBERNATE_CALLBACKS
 322         case PM_EVENT_FREEZE:
 323         case PM_EVENT_QUIESCE:
 324                 return ops->freeze;
 325         case PM_EVENT_HIBERNATE:
 326                 return ops->poweroff;
 327         case PM_EVENT_THAW:
 328         case PM_EVENT_RECOVER:
 329                 return ops->thaw;
 330                 break;
 331         case PM_EVENT_RESTORE:
 332                 return ops->restore;
 333 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 334         }
 335
 336         return NULL;
 337 }
 338
 339 /**
 340  * pm_late_early_op - Return the PM operation appropriate for given PM event.
 341  * @ops: PM operations to choose from.
 342  * @state: PM transition of the system being carried out.
 343  *
 344  * Runtime PM is disabled for @dev while this function is being executed.
 345  */
 346 static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
 347                                       pm_message_t state)
 348 {
 349         switch (state.event) {
 350 #ifdef CONFIG_SUSPEND
 351         case PM_EVENT_SUSPEND:
 352                 return ops->suspend_late;
 353         case PM_EVENT_RESUME:
 354                 return ops->resume_early;
 355 #endif /* CONFIG_SUSPEND */
 356 #ifdef CONFIG_HIBERNATE_CALLBACKS
 357         case PM_EVENT_FREEZE:
 358         case PM_EVENT_QUIESCE:
 359                 return ops->freeze_late;
 360         case PM_EVENT_HIBERNATE:
 361                 return ops->poweroff_late;
 362         case PM_EVENT_THAW:
 363         case PM_EVENT_RECOVER:
 364                 return ops->thaw_early;
 365         case PM_EVENT_RESTORE:
 366                 return ops->restore_early;
 367 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 368         }
 369
 370         return NULL;
 371 }
 372
 373 /**
 374  * pm_noirq_op - Return the PM operation appropriate for given PM event.
 375  * @ops: PM operations to choose from.
 376  * @state: PM transition of the system being carried out.
 377  *
 378  * The driver of @dev will not receive interrupts while this function is being
 379  * executed.
 380  */
 381 static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
 382 {
 383         switch (state.event) {
 384 #ifdef CONFIG_SUSPEND
 385         case PM_EVENT_SUSPEND:
 386                 return ops->suspend_noirq;
 387         case PM_EVENT_RESUME:
 388                 return ops->resume_noirq;
 389 #endif /* CONFIG_SUSPEND */
 390 #ifdef CONFIG_HIBERNATE_CALLBACKS
 391         case PM_EVENT_FREEZE:
 392         case PM_EVENT_QUIESCE:
 393                 return ops->freeze_noirq;
 394         case PM_EVENT_HIBERNATE:
 395                 return ops->poweroff_noirq;
 396         case PM_EVENT_THAW:
 397         case PM_EVENT_RECOVER:
 398                 return ops->thaw_noirq;
 399         case PM_EVENT_RESTORE:
 400                 return ops->restore_noirq;
 401 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 402         }
 403
 404         return NULL;
 405 }
 406
 407 static void pm_dev_dbg(struct device *dev, pm_message_t state, const char *info)
 408 {
 409         dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
 410                 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
 411                 ", may wakeup" : "");
 412 }
 413
 414 static void pm_dev_err(struct device *dev, pm_message_t state, const char *info,
 415                         int error)
 416 {
 417         printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
 418                 dev_name(dev), pm_verb(state.event), info, error);
 419 }
 420
 421 static void dpm_show_time(ktime_t starttime, pm_message_t state, int error,
 422                           const char *info)
 423 {
 424         ktime_t calltime;
 425         u64 usecs64;
 426         int usecs;
 427
 428         calltime = ktime_get();
 429         usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
 430         do_div(usecs64, NSEC_PER_USEC);
 431         usecs = usecs64;
 432         if (usecs == 0)
 433                 usecs = 1;
 434
 435         pm_pr_dbg("%s%s%s of devices %s after %ld.%03ld msecs\n",
 436                   info ?: "", info ? " " : "", pm_verb(state.event),
 437                   error ? "aborted" : "complete",
 438                   usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
 439 }
 440
 441 static int dpm_run_callback(pm_callback_t cb, struct device *dev,
 442                             pm_message_t state, const char *info)
 443 {
 444         ktime_t calltime;
 445         int error;
 446
 447         if (!cb)
 448                 return 0;
 449
 450         calltime = initcall_debug_start(dev);
 451
 452         pm_dev_dbg(dev, state, info);
 453         trace_device_pm_callback_start(dev, info, state.event);
 454         error = cb(dev);
 455         trace_device_pm_callback_end(dev, error);
 456         suspend_report_result(cb, error);
 457
 458         initcall_debug_report(dev, calltime, error, state, info);
 459
 460         return error;
 461 }
 462
 463 #ifdef CONFIG_DPM_WATCHDOG
 464 struct dpm_watchdog {
 465         struct device           *dev;
 466         struct task_struct      *tsk;
 467         struct timer_list       timer;
 468 };
 469
 470 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
 471         struct dpm_watchdog wd
 472
 473 /**
 474  * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
 475  * @data: Watchdog object address.
 476  *
 477  * Called when a driver has timed out suspending or resuming.
 478  * There's not much we can do here to recover so panic() to
 479  * capture a crash-dump in pstore.
 480  */
 481 static void dpm_watchdog_handler(struct timer_list *t)
 482 {
 483         struct dpm_watchdog *wd = from_timer(wd, t, timer);
 484
 485         dev_emerg(wd->dev, "**** DPM device timeout ****\n");
 486         show_stack(wd->tsk, NULL);
 487         panic("%s %s: unrecoverable failure\n",
 488                 dev_driver_string(wd->dev), dev_name(wd->dev));
 489 }
 490
 491 /**
 492  * dpm_watchdog_set - Enable pm watchdog for given device.
 493  * @wd: Watchdog. Must be allocated on the stack.
 494  * @dev: Device to handle.
 495  */
 496 static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
 497 {
 498         struct timer_list *timer = &wd->timer;
 499
 500         wd->dev = dev;
 501         wd->tsk = current;
 502
 503         timer_setup_on_stack(timer, dpm_watchdog_handler, 0);
 504         /* use same timeout value for both suspend and resume */
 505         timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
 506         add_timer(timer);
 507 }
 508
 509 /**
 510  * dpm_watchdog_clear - Disable suspend/resume watchdog.
 511  * @wd: Watchdog to disable.
 512  */
 513 static void dpm_watchdog_clear(struct dpm_watchdog *wd)
 514 {
 515         struct timer_list *timer = &wd->timer;
 516
 517         del_timer_sync(timer);
 518         destroy_timer_on_stack(timer);
 519 }
 520 #else
 521 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
 522 #define dpm_watchdog_set(x, y)
 523 #define dpm_watchdog_clear(x)
 524 #endif
 525
 526 /*------------------------- Resume routines -------------------------*/
 527
 528 /**
 529  * dev_pm_skip_next_resume_phases - Skip next system resume phases for device.
 530  * @dev: Target device.
 531  *
 532  * Make the core skip the "early resume" and "resume" phases for @dev.
 533  *
 534  * This function can be called by middle-layer code during the "noirq" phase of
 535  * system resume if necessary, but not by device drivers.
 536  */
 537 void dev_pm_skip_next_resume_phases(struct device *dev)
 538 {
 539         dev->power.is_late_suspended = false;
 540         dev->power.is_suspended = false;
 541 }
 542
 543 /**
 544  * device_resume_noirq - Execute a "noirq resume" callback for given device.
 545  * @dev: Device to handle.
 546  * @state: PM transition of the system being carried out.
 547  * @async: If true, the device is being resumed asynchronously.
 548  *
 549  * The driver of @dev will not receive interrupts while this function is being
 550  * executed.
 551  */
 552 static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
 553 {
 554         pm_callback_t callback = NULL;
 555         const char *info = NULL;
 556         int error = 0;
 557
 558         TRACE_DEVICE(dev);
 559         TRACE_RESUME(0);
 560
 561         if (dev->power.syscore || dev->power.direct_complete)
 562                 goto Out;
 563
 564         if (!dev->power.is_noirq_suspended)
 565                 goto Out;
 566
 567         dpm_wait_for_superior(dev, async);
 568
 569         if (dev->pm_domain) {
 570                 info = "noirq power domain ";
 571                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
 572         } else if (dev->type && dev->type->pm) {
 573                 info = "noirq type ";
 574                 callback = pm_noirq_op(dev->type->pm, state);
 575         } else if (dev->class && dev->class->pm) {
 576                 info = "noirq class ";
 577                 callback = pm_noirq_op(dev->class->pm, state);
 578         } else if (dev->bus && dev->bus->pm) {
 579                 info = "noirq bus ";
 580                 callback = pm_noirq_op(dev->bus->pm, state);
 581         }
 582
 583         if (!callback && dev->driver && dev->driver->pm) {
 584                 info = "noirq driver ";
 585                 callback = pm_noirq_op(dev->driver->pm, state);
 586         }
 587
 588         error = dpm_run_callback(callback, dev, state, info);
 589         dev->power.is_noirq_suspended = false;
 590
 591  Out:
 592         complete_all(&dev->power.completion);
 593         TRACE_RESUME(error);
 594         return error;
 595 }
 596
 597 static bool is_async(struct device *dev)
 598 {
 599         return dev->power.async_suspend && pm_async_enabled
 600                 && !pm_trace_is_enabled();
 601 }
 602
 603 static void async_resume_noirq(void *data, async_cookie_t cookie)
 604 {
 605         struct device *dev = (struct device *)data;
 606         int error;
 607
 608         error = device_resume_noirq(dev, pm_transition, true);
 609         if (error)
 610                 pm_dev_err(dev, pm_transition, " async", error);
 611
 612         put_device(dev);
 613 }
 614
 615 void dpm_noirq_resume_devices(pm_message_t state)
 616 {
 617         struct device *dev;
 618         ktime_t starttime = ktime_get();
 619
 620         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
 621         mutex_lock(&dpm_list_mtx);
 622         pm_transition = state;
 623
 624         /*
 625          * Advanced the async threads upfront,
 626          * in case the starting of async threads is
 627          * delayed by non-async resuming devices.
 628          */
 629         list_for_each_entry(dev, &dpm_noirq_list, power.entry) {
 630                 reinit_completion(&dev->power.completion);
 631                 if (is_async(dev)) {
 632                         get_device(dev);
 633                         async_schedule(async_resume_noirq, dev);
 634                 }
 635         }
 636
 637         while (!list_empty(&dpm_noirq_list)) {
 638                 dev = to_device(dpm_noirq_list.next);
 639                 get_device(dev);
 640                 list_move_tail(&dev->power.entry, &dpm_late_early_list);
 641                 mutex_unlock(&dpm_list_mtx);
 642
 643                 if (!is_async(dev)) {
 644                         int error;
 645
 646                         error = device_resume_noirq(dev, state, false);
 647                         if (error) {
 648                                 suspend_stats.failed_resume_noirq++;
 649                                 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
 650                                 dpm_save_failed_dev(dev_name(dev));
 651                                 pm_dev_err(dev, state, " noirq", error);
 652                         }
 653                 }
 654
 655                 mutex_lock(&dpm_list_mtx);
 656                 put_device(dev);
 657         }
 658         mutex_unlock(&dpm_list_mtx);
 659         async_synchronize_full();
 660         dpm_show_time(starttime, state, 0, "noirq");
 661         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
 662 }
 663
 664 void dpm_noirq_end(void)
 665 {
 666         resume_device_irqs();
 667         device_wakeup_disarm_wake_irqs();
 668         cpuidle_resume();
 669 }
 670
 671 /**
 672  * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
 673  * @state: PM transition of the system being carried out.
 674  *
 675  * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
 676  * allow device drivers' interrupt handlers to be called.
 677  */
 678 void dpm_resume_noirq(pm_message_t state)
 679 {
 680         dpm_noirq_resume_devices(state);
 681         dpm_noirq_end();
 682 }
 683
 684 /**
 685  * device_resume_early - Execute an "early resume" callback for given device.
 686  * @dev: Device to handle.
 687  * @state: PM transition of the system being carried out.
 688  * @async: If true, the device is being resumed asynchronously.
 689  *
 690  * Runtime PM is disabled for @dev while this function is being executed.
 691  */
 692 static int device_resume_early(struct device *dev, pm_message_t state, bool async)
 693 {
 694         pm_callback_t callback = NULL;
 695         const char *info = NULL;
 696         int error = 0;
 697
 698         TRACE_DEVICE(dev);
 699         TRACE_RESUME(0);
 700
 701         if (dev->power.syscore || dev->power.direct_complete)
 702                 goto Out;
 703
 704         if (!dev->power.is_late_suspended)
 705                 goto Out;
 706
 707         dpm_wait_for_superior(dev, async);
 708
 709         if (dev->pm_domain) {
 710                 info = "early power domain ";
 711                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
 712         } else if (dev->type && dev->type->pm) {
 713                 info = "early type ";
 714                 callback = pm_late_early_op(dev->type->pm, state);
 715         } else if (dev->class && dev->class->pm) {
 716                 info = "early class ";
 717                 callback = pm_late_early_op(dev->class->pm, state);
 718         } else if (dev->bus && dev->bus->pm) {
 719                 info = "early bus ";
 720                 callback = pm_late_early_op(dev->bus->pm, state);
 721         }
 722
 723         if (!callback && dev->driver && dev->driver->pm) {
 724                 info = "early driver ";
 725                 callback = pm_late_early_op(dev->driver->pm, state);
 726         }
 727
 728         error = dpm_run_callback(callback, dev, state, info);
 729         dev->power.is_late_suspended = false;
 730
 731  Out:
 732         TRACE_RESUME(error);
 733
 734         pm_runtime_enable(dev);
 735         complete_all(&dev->power.completion);
 736         return error;
 737 }
 738
 739 static void async_resume_early(void *data, async_cookie_t cookie)
 740 {
 741         struct device *dev = (struct device *)data;
 742         int error;
 743
 744         error = device_resume_early(dev, pm_transition, true);
 745         if (error)
 746                 pm_dev_err(dev, pm_transition, " async", error);
 747
 748         put_device(dev);
 749 }
 750
 751 /**
 752  * dpm_resume_early - Execute "early resume" callbacks for all devices.
 753  * @state: PM transition of the system being carried out.
 754  */
 755 void dpm_resume_early(pm_message_t state)
 756 {
 757         struct device *dev;
 758         ktime_t starttime = ktime_get();
 759
 760         trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
 761         mutex_lock(&dpm_list_mtx);
 762         pm_transition = state;
 763
 764         /*
 765          * Advanced the async threads upfront,
 766          * in case the starting of async threads is
 767          * delayed by non-async resuming devices.
 768          */
 769         list_for_each_entry(dev, &dpm_late_early_list, power.entry) {
 770                 reinit_completion(&dev->power.completion);
 771                 if (is_async(dev)) {
 772                         get_device(dev);
 773                         async_schedule(async_resume_early, dev);
 774                 }
 775         }
 776
 777         while (!list_empty(&dpm_late_early_list)) {
 778                 dev = to_device(dpm_late_early_list.next);
 779                 get_device(dev);
 780                 list_move_tail(&dev->power.entry, &dpm_suspended_list);
 781                 mutex_unlock(&dpm_list_mtx);
 782
 783                 if (!is_async(dev)) {
 784                         int error;
 785
 786                         error = device_resume_early(dev, state, false);
 787                         if (error) {
 788                                 suspend_stats.failed_resume_early++;
 789                                 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
 790                                 dpm_save_failed_dev(dev_name(dev));
 791                                 pm_dev_err(dev, state, " early", error);
 792                         }
 793                 }
 794                 mutex_lock(&dpm_list_mtx);
 795                 put_device(dev);
 796         }
 797         mutex_unlock(&dpm_list_mtx);
 798         async_synchronize_full();
 799         dpm_show_time(starttime, state, 0, "early");
 800         trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
 801 }
 802
 803 /**
 804  * dpm_resume_start - Execute "noirq" and "early" device callbacks.
 805  * @state: PM transition of the system being carried out.
 806  */
 807 void dpm_resume_start(pm_message_t state)
 808 {
 809         dpm_resume_noirq(state);
 810         dpm_resume_early(state);
 811 }
 812 EXPORT_SYMBOL_GPL(dpm_resume_start);
 813
 814 /**
 815  * device_resume - Execute "resume" callbacks for given device.
 816  * @dev: Device to handle.
 817  * @state: PM transition of the system being carried out.
 818  * @async: If true, the device is being resumed asynchronously.
 819  */
 820 static int device_resume(struct device *dev, pm_message_t state, bool async)
 821 {
 822         pm_callback_t callback = NULL;
 823         const char *info = NULL;
 824         int error = 0;
 825         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
 826
 827         TRACE_DEVICE(dev);
 828         TRACE_RESUME(0);
 829
 830         if (dev->power.syscore)
 831                 goto Complete;
 832
 833         if (dev->power.direct_complete) {
 834                 /* Match the pm_runtime_disable() in __device_suspend(). */
 835                 pm_runtime_enable(dev);
 836                 goto Complete;
 837         }
 838
 839         dpm_wait_for_superior(dev, async);
 840         dpm_watchdog_set(&wd, dev);
 841         device_lock(dev);
 842
 843         /*
 844          * This is a fib.  But we'll allow new children to be added below
 845          * a resumed device, even if the device hasn't been completed yet.
 846          */
 847         dev->power.is_prepared = false;
 848
 849         if (!dev->power.is_suspended)
 850                 goto Unlock;
 851
 852         if (dev->pm_domain) {
 853                 info = "power domain ";
 854                 callback = pm_op(&dev->pm_domain->ops, state);
 855                 goto Driver;
 856         }
 857
 858         if (dev->type && dev->type->pm) {
 859                 info = "type ";
 860                 callback = pm_op(dev->type->pm, state);
 861                 goto Driver;
 862         }
 863
 864         if (dev->class && dev->class->pm) {
 865                 info = "class ";
 866                 callback = pm_op(dev->class->pm, state);
 867                 goto Driver;
 868         }
 869
 870         if (dev->bus) {
 871                 if (dev->bus->pm) {
 872                         info = "bus ";
 873                         callback = pm_op(dev->bus->pm, state);
 874                 } else if (dev->bus->resume) {
 875                         info = "legacy bus ";
 876                         callback = dev->bus->resume;
 877                         goto End;
 878                 }
 879         }
 880
 881  Driver:
 882         if (!callback && dev->driver && dev->driver->pm) {
 883                 info = "driver ";
 884                 callback = pm_op(dev->driver->pm, state);
 885         }
 886
 887  End:
 888         error = dpm_run_callback(callback, dev, state, info);
 889         dev->power.is_suspended = false;
 890
 891  Unlock:
 892         device_unlock(dev);
 893         dpm_watchdog_clear(&wd);
 894
 895  Complete:
 896         complete_all(&dev->power.completion);
 897
 898         TRACE_RESUME(error);
 899
 900         return error;
 901 }
 902
 903 static void async_resume(void *data, async_cookie_t cookie)
 904 {
 905         struct device *dev = (struct device *)data;
 906         int error;
 907
 908         error = device_resume(dev, pm_transition, true);
 909         if (error)
 910                 pm_dev_err(dev, pm_transition, " async", error);
 911         put_device(dev);
 912 }
 913
 914 /**
 915  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
 916  * @state: PM transition of the system being carried out.
 917  *
 918  * Execute the appropriate "resume" callback for all devices whose status
 919  * indicates that they are suspended.
 920  */
 921 void dpm_resume(pm_message_t state)
 922 {
 923         struct device *dev;
 924         ktime_t starttime = ktime_get();
 925
 926         trace_suspend_resume(TPS("dpm_resume"), state.event, true);
 927         might_sleep();
 928
 929         mutex_lock(&dpm_list_mtx);
 930         pm_transition = state;
 931         async_error = 0;
 932
 933         list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
 934                 reinit_completion(&dev->power.completion);
 935                 if (is_async(dev)) {
 936                         get_device(dev);
 937                         async_schedule(async_resume, dev);
 938                 }
 939         }
 940
 941         while (!list_empty(&dpm_suspended_list)) {
 942                 dev = to_device(dpm_suspended_list.next);
 943                 get_device(dev);
 944                 if (!is_async(dev)) {
 945                         int error;
 946
 947                         mutex_unlock(&dpm_list_mtx);
 948
 949                         error = device_resume(dev, state, false);
 950                         if (error) {
 951                                 suspend_stats.failed_resume++;
 952                                 dpm_save_failed_step(SUSPEND_RESUME);
 953                                 dpm_save_failed_dev(dev_name(dev));
 954                                 pm_dev_err(dev, state, "", error);
 955                         }
 956
 957                         mutex_lock(&dpm_list_mtx);
 958                 }
 959                 if (!list_empty(&dev->power.entry))
 960                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
 961                 put_device(dev);
 962         }
 963         mutex_unlock(&dpm_list_mtx);
 964         async_synchronize_full();
 965         dpm_show_time(starttime, state, 0, NULL);
 966
 967         cpufreq_resume();
 968         trace_suspend_resume(TPS("dpm_resume"), state.event, false);
 969 }
 970
 971 /**
 972  * device_complete - Complete a PM transition for given device.
 973  * @dev: Device to handle.
 974  * @state: PM transition of the system being carried out.
 975  */
 976 static void device_complete(struct device *dev, pm_message_t state)
 977 {
 978         void (*callback)(struct device *) = NULL;
 979         const char *info = NULL;
 980
 981         if (dev->power.syscore)
 982                 return;
 983
 984         device_lock(dev);
 985
 986         if (dev->pm_domain) {
 987                 info = "completing power domain ";
 988                 callback = dev->pm_domain->ops.complete;
 989         } else if (dev->type && dev->type->pm) {
 990                 info = "completing type ";
 991                 callback = dev->type->pm->complete;
 992         } else if (dev->class && dev->class->pm) {
 993                 info = "completing class ";
 994                 callback = dev->class->pm->complete;
 995         } else if (dev->bus && dev->bus->pm) {
 996                 info = "completing bus ";
 997                 callback = dev->bus->pm->complete;
 998         }
 999
1000         if (!callback && dev->driver && dev->driver->pm) {
1001                 info = "completing driver ";
1002                 callback = dev->driver->pm->complete;
1003         }
1004
1005         if (callback) {
1006                 pm_dev_dbg(dev, state, info);
1007                 callback(dev);
1008         }
1009
1010         device_unlock(dev);
1011
1012         pm_runtime_put(dev);
1013 }
1014
1015 /**
1016  * dpm_complete - Complete a PM transition for all non-sysdev devices.
1017  * @state: PM transition of the system being carried out.
1018  *
1019  * Execute the ->complete() callbacks for all devices whose PM status is not
1020  * DPM_ON (this allows new devices to be registered).
1021  */
1022 void dpm_complete(pm_message_t state)
1023 {
1024         struct list_head list;
1025
1026         trace_suspend_resume(TPS("dpm_complete"), state.event, true);
1027         might_sleep();
1028
1029         INIT_LIST_HEAD(&list);
1030         mutex_lock(&dpm_list_mtx);
1031         while (!list_empty(&dpm_prepared_list)) {
1032                 struct device *dev = to_device(dpm_prepared_list.prev);
1033
1034                 get_device(dev);
1035                 dev->power.is_prepared = false;
1036                 list_move(&dev->power.entry, &list);
1037                 mutex_unlock(&dpm_list_mtx);
1038
1039                 trace_device_pm_callback_start(dev, "", state.event);
1040                 device_complete(dev, state);
1041                 trace_device_pm_callback_end(dev, 0);
1042
1043                 mutex_lock(&dpm_list_mtx);
1044                 put_device(dev);
1045         }
1046         list_splice(&list, &dpm_list);
1047         mutex_unlock(&dpm_list_mtx);
1048
1049         /* Allow device probing and trigger re-probing of deferred devices */
1050         device_unblock_probing();
1051         trace_suspend_resume(TPS("dpm_complete"), state.event, false);
1052 }
1053
1054 /**
1055  * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1056  * @state: PM transition of the system being carried out.
1057  *
1058  * Execute "resume" callbacks for all devices and complete the PM transition of
1059  * the system.
1060  */
1061 void dpm_resume_end(pm_message_t state)
1062 {
1063         dpm_resume(state);
1064         dpm_complete(state);
1065 }
1066 EXPORT_SYMBOL_GPL(dpm_resume_end);
1067
1068
1069 /*------------------------- Suspend routines -------------------------*/
1070
1071 /**
1072  * resume_event - Return a "resume" message for given "suspend" sleep state.
1073  * @sleep_state: PM message representing a sleep state.
1074  *
1075  * Return a PM message representing the resume event corresponding to given
1076  * sleep state.
1077  */
1078 static pm_message_t resume_event(pm_message_t sleep_state)
1079 {
1080         switch (sleep_state.event) {
1081         case PM_EVENT_SUSPEND:
1082                 return PMSG_RESUME;
1083         case PM_EVENT_FREEZE:
1084         case PM_EVENT_QUIESCE:
1085                 return PMSG_RECOVER;
1086         case PM_EVENT_HIBERNATE:
1087                 return PMSG_RESTORE;
1088         }
1089         return PMSG_ON;
1090 }
1091
1092 /**
1093  * __device_suspend_noirq - Execute a "noirq suspend" callback for given device.
1094  * @dev: Device to handle.
1095  * @state: PM transition of the system being carried out.
1096  * @async: If true, the device is being suspended asynchronously.
1097  *
1098  * The driver of @dev will not receive interrupts while this function is being
1099  * executed.
1100  */
1101 static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1102 {
1103         pm_callback_t callback = NULL;
1104         const char *info = NULL;
1105         int error = 0;
1106
1107         TRACE_DEVICE(dev);
1108         TRACE_SUSPEND(0);
1109
1110         dpm_wait_for_subordinate(dev, async);
1111
1112         if (async_error)
1113                 goto Complete;
1114
1115         if (pm_wakeup_pending()) {
1116                 async_error = -EBUSY;
1117                 goto Complete;
1118         }
1119
1120         if (dev->power.syscore || dev->power.direct_complete)
1121                 goto Complete;
1122
1123         if (dev->pm_domain) {
1124                 info = "noirq power domain ";
1125                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
1126         } else if (dev->type && dev->type->pm) {
1127                 info = "noirq type ";
1128                 callback = pm_noirq_op(dev->type->pm, state);
1129         } else if (dev->class && dev->class->pm) {
1130                 info = "noirq class ";
1131                 callback = pm_noirq_op(dev->class->pm, state);
1132         } else if (dev->bus && dev->bus->pm) {
1133                 info = "noirq bus ";
1134                 callback = pm_noirq_op(dev->bus->pm, state);
1135         }
1136
1137         if (!callback && dev->driver && dev->driver->pm) {
1138                 info = "noirq driver ";
1139                 callback = pm_noirq_op(dev->driver->pm, state);
1140         }
1141
1142         error = dpm_run_callback(callback, dev, state, info);
1143         if (!error)
1144                 dev->power.is_noirq_suspended = true;
1145         else
1146                 async_error = error;
1147
1148 Complete:
1149         complete_all(&dev->power.completion);
1150         TRACE_SUSPEND(error);
1151         return error;
1152 }
1153
1154 static void async_suspend_noirq(void *data, async_cookie_t cookie)
1155 {
1156         struct device *dev = (struct device *)data;
1157         int error;
1158
1159         error = __device_suspend_noirq(dev, pm_transition, true);
1160         if (error) {
1161                 dpm_save_failed_dev(dev_name(dev));
1162                 pm_dev_err(dev, pm_transition, " async", error);
1163         }
1164
1165         put_device(dev);
1166 }
1167
1168 static int device_suspend_noirq(struct device *dev)
1169 {
1170         reinit_completion(&dev->power.completion);
1171
1172         if (is_async(dev)) {
1173                 get_device(dev);
1174                 async_schedule(async_suspend_noirq, dev);
1175                 return 0;
1176         }
1177         return __device_suspend_noirq(dev, pm_transition, false);
1178 }
1179
1180 void dpm_noirq_begin(void)
1181 {
1182         cpuidle_pause();
1183         device_wakeup_arm_wake_irqs();
1184         suspend_device_irqs();
1185 }
1186
1187 int dpm_noirq_suspend_devices(pm_message_t state)
1188 {
1189         ktime_t starttime = ktime_get();
1190         int error = 0;
1191
1192         trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1193         mutex_lock(&dpm_list_mtx);
1194         pm_transition = state;
1195         async_error = 0;
1196
1197         while (!list_empty(&dpm_late_early_list)) {
1198                 struct device *dev = to_device(dpm_late_early_list.prev);
1199
1200                 get_device(dev);
1201                 mutex_unlock(&dpm_list_mtx);
1202
1203                 error = device_suspend_noirq(dev);
1204
1205                 mutex_lock(&dpm_list_mtx);
1206                 if (error) {
1207                         pm_dev_err(dev, state, " noirq", error);
1208                         dpm_save_failed_dev(dev_name(dev));
1209                         put_device(dev);
1210                         break;
1211                 }
1212                 if (!list_empty(&dev->power.entry))
1213                         list_move(&dev->power.entry, &dpm_noirq_list);
1214                 put_device(dev);
1215
1216                 if (async_error)
1217                         break;
1218         }
1219         mutex_unlock(&dpm_list_mtx);
1220         async_synchronize_full();
1221         if (!error)
1222                 error = async_error;
1223
1224         if (error) {
1225                 suspend_stats.failed_suspend_noirq++;
1226                 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1227         }
1228         dpm_show_time(starttime, state, error, "noirq");
1229         trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1230         return error;
1231 }
1232
1233 /**
1234  * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1235  * @state: PM transition of the system being carried out.
1236  *
1237  * Prevent device drivers' interrupt handlers from being called and invoke
1238  * "noirq" suspend callbacks for all non-sysdev devices.
1239  */
1240 int dpm_suspend_noirq(pm_message_t state)
1241 {
1242         int ret;
1243
1244         dpm_noirq_begin();
1245         ret = dpm_noirq_suspend_devices(state);
1246         if (ret)
1247                 dpm_resume_noirq(resume_event(state));
1248
1249         return ret;
1250 }
1251
1252 /**
1253  * __device_suspend_late - Execute a "late suspend" callback for given device.
1254  * @dev: Device to handle.
1255  * @state: PM transition of the system being carried out.
1256  * @async: If true, the device is being suspended asynchronously.
1257  *
1258  * Runtime PM is disabled for @dev while this function is being executed.
1259  */
1260 static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1261 {
1262         pm_callback_t callback = NULL;
1263         const char *info = NULL;
1264         int error = 0;
1265
1266         TRACE_DEVICE(dev);
1267         TRACE_SUSPEND(0);
1268
1269         __pm_runtime_disable(dev, false);
1270
1271         dpm_wait_for_subordinate(dev, async);
1272
1273         if (async_error)
1274                 goto Complete;
1275
1276         if (pm_wakeup_pending()) {
1277                 async_error = -EBUSY;
1278                 goto Complete;
1279         }
1280
1281         if (dev->power.syscore || dev->power.direct_complete)
1282                 goto Complete;
1283
1284         if (dev->pm_domain) {
1285                 info = "late power domain ";
1286                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
1287         } else if (dev->type && dev->type->pm) {
1288                 info = "late type ";
1289                 callback = pm_late_early_op(dev->type->pm, state);
1290         } else if (dev->class && dev->class->pm) {
1291                 info = "late class ";
1292                 callback = pm_late_early_op(dev->class->pm, state);
1293         } else if (dev->bus && dev->bus->pm) {
1294                 info = "late bus ";
1295                 callback = pm_late_early_op(dev->bus->pm, state);
1296         }
1297
1298         if (!callback && dev->driver && dev->driver->pm) {
1299                 info = "late driver ";
1300                 callback = pm_late_early_op(dev->driver->pm, state);
1301         }
1302
1303         error = dpm_run_callback(callback, dev, state, info);
1304         if (!error)
1305                 dev->power.is_late_suspended = true;
1306         else
1307                 async_error = error;
1308
1309 Complete:
1310         TRACE_SUSPEND(error);
1311         complete_all(&dev->power.completion);
1312         return error;
1313 }
1314
1315 static void async_suspend_late(void *data, async_cookie_t cookie)
1316 {
1317         struct device *dev = (struct device *)data;
1318         int error;
1319
1320         error = __device_suspend_late(dev, pm_transition, true);
1321         if (error) {
1322                 dpm_save_failed_dev(dev_name(dev));
1323                 pm_dev_err(dev, pm_transition, " async", error);
1324         }
1325         put_device(dev);
1326 }
1327
1328 static int device_suspend_late(struct device *dev)
1329 {
1330         reinit_completion(&dev->power.completion);
1331
1332         if (is_async(dev)) {
1333                 get_device(dev);
1334                 async_schedule(async_suspend_late, dev);
1335                 return 0;
1336         }
1337
1338         return __device_suspend_late(dev, pm_transition, false);
1339 }
1340
1341 /**
1342  * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1343  * @state: PM transition of the system being carried out.
1344  */
1345 int dpm_suspend_late(pm_message_t state)
1346 {
1347         ktime_t starttime = ktime_get();
1348         int error = 0;
1349
1350         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1351         mutex_lock(&dpm_list_mtx);
1352         pm_transition = state;
1353         async_error = 0;
1354
1355         while (!list_empty(&dpm_suspended_list)) {
1356                 struct device *dev = to_device(dpm_suspended_list.prev);
1357
1358                 get_device(dev);
1359                 mutex_unlock(&dpm_list_mtx);
1360
1361                 error = device_suspend_late(dev);
1362
1363                 mutex_lock(&dpm_list_mtx);
1364                 if (!list_empty(&dev->power.entry))
1365                         list_move(&dev->power.entry, &dpm_late_early_list);
1366
1367                 if (error) {
1368                         pm_dev_err(dev, state, " late", error);
1369                         dpm_save_failed_dev(dev_name(dev));
1370                         put_device(dev);
1371                         break;
1372                 }
1373                 put_device(dev);
1374
1375                 if (async_error)
1376                         break;
1377         }
1378         mutex_unlock(&dpm_list_mtx);
1379         async_synchronize_full();
1380         if (!error)
1381                 error = async_error;
1382         if (error) {
1383                 suspend_stats.failed_suspend_late++;
1384                 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1385                 dpm_resume_early(resume_event(state));
1386         }
1387         dpm_show_time(starttime, state, error, "late");
1388         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1389         return error;
1390 }
1391
1392 /**
1393  * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1394  * @state: PM transition of the system being carried out.
1395  */
1396 int dpm_suspend_end(pm_message_t state)
1397 {
1398         int error = dpm_suspend_late(state);
1399         if (error)
1400                 return error;
1401
1402         error = dpm_suspend_noirq(state);
1403         if (error) {
1404                 dpm_resume_early(resume_event(state));
1405                 return error;
1406         }
1407
1408         return 0;
1409 }
1410 EXPORT_SYMBOL_GPL(dpm_suspend_end);
1411
1412 /**
1413  * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1414  * @dev: Device to suspend.
1415  * @state: PM transition of the system being carried out.
1416  * @cb: Suspend callback to execute.
1417  * @info: string description of caller.
1418  */
1419 static int legacy_suspend(struct device *dev, pm_message_t state,
1420                           int (*cb)(struct device *dev, pm_message_t state),
1421                           const char *info)
1422 {
1423         int error;
1424         ktime_t calltime;
1425
1426         calltime = initcall_debug_start(dev);
1427
1428         trace_device_pm_callback_start(dev, info, state.event);
1429         error = cb(dev, state);
1430         trace_device_pm_callback_end(dev, error);
1431         suspend_report_result(cb, error);
1432
1433         initcall_debug_report(dev, calltime, error, state, info);
1434
1435         return error;
1436 }
1437
1438 static void dpm_clear_suppliers_direct_complete(struct device *dev)
1439 {
1440         struct device_link *link;
1441         int idx;
1442
1443         idx = device_links_read_lock();
1444
1445         list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) {
1446                 spin_lock_irq(&link->supplier->power.lock);
1447                 link->supplier->power.direct_complete = false;
1448                 spin_unlock_irq(&link->supplier->power.lock);
1449         }
1450
1451         device_links_read_unlock(idx);
1452 }
1453
1454 /**
1455  * __device_suspend - Execute "suspend" callbacks for given device.
1456  * @dev: Device to handle.
1457  * @state: PM transition of the system being carried out.
1458  * @async: If true, the device is being suspended asynchronously.
1459  */
1460 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1461 {
1462         pm_callback_t callback = NULL;
1463         const char *info = NULL;
1464         int error = 0;
1465         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1466
1467         TRACE_DEVICE(dev);
1468         TRACE_SUSPEND(0);
1469
1470         dpm_wait_for_subordinate(dev, async);
1471
1472         if (async_error)
1473                 goto Complete;
1474
1475         /*
1476          * If a device configured to wake up the system from sleep states
1477          * has been suspended at run time and there's a resume request pending
1478          * for it, this is equivalent to the device signaling wakeup, so the
1479          * system suspend operation should be aborted.
1480          */
1481         if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1482                 pm_wakeup_event(dev, 0);
1483
1484         if (pm_wakeup_pending()) {
1485                 async_error = -EBUSY;
1486                 goto Complete;
1487         }
1488
1489         if (dev->power.syscore)
1490                 goto Complete;
1491
1492         if (dev->power.direct_complete) {
1493                 if (pm_runtime_status_suspended(dev)) {
1494                         pm_runtime_disable(dev);
1495                         if (pm_runtime_status_suspended(dev))
1496                                 goto Complete;
1497
1498                         pm_runtime_enable(dev);
1499                 }
1500                 dev->power.direct_complete = false;
1501         }
1502
1503         dpm_watchdog_set(&wd, dev);
1504         device_lock(dev);
1505
1506         if (dev->pm_domain) {
1507                 info = "power domain ";
1508                 callback = pm_op(&dev->pm_domain->ops, state);
1509                 goto Run;
1510         }
1511
1512         if (dev->type && dev->type->pm) {
1513                 info = "type ";
1514                 callback = pm_op(dev->type->pm, state);
1515                 goto Run;
1516         }
1517
1518         if (dev->class && dev->class->pm) {
1519                 info = "class ";
1520                 callback = pm_op(dev->class->pm, state);
1521                 goto Run;
1522         }
1523
1524         if (dev->bus) {
1525                 if (dev->bus->pm) {
1526                         info = "bus ";
1527                         callback = pm_op(dev->bus->pm, state);
1528                 } else if (dev->bus->suspend) {
1529                         pm_dev_dbg(dev, state, "legacy bus ");
1530                         error = legacy_suspend(dev, state, dev->bus->suspend,
1531                                                 "legacy bus ");
1532                         goto End;
1533                 }
1534         }
1535
1536  Run:
1537         if (!callback && dev->driver && dev->driver->pm) {
1538                 info = "driver ";
1539                 callback = pm_op(dev->driver->pm, state);
1540         }
1541
1542         error = dpm_run_callback(callback, dev, state, info);
1543
1544  End:
1545         if (!error) {
1546                 struct device *parent = dev->parent;
1547
1548                 dev->power.is_suspended = true;
1549                 if (parent) {
1550                         spin_lock_irq(&parent->power.lock);
1551
1552                         dev->parent->power.direct_complete = false;
1553                         if (dev->power.wakeup_path
1554                             && !dev->parent->power.ignore_children)
1555                                 dev->parent->power.wakeup_path = true;
1556
1557                         spin_unlock_irq(&parent->power.lock);
1558                 }
1559                 dpm_clear_suppliers_direct_complete(dev);
1560         }
1561
1562         device_unlock(dev);
1563         dpm_watchdog_clear(&wd);
1564
1565  Complete:
1566         if (error)
1567                 async_error = error;
1568
1569         complete_all(&dev->power.completion);
1570         TRACE_SUSPEND(error);
1571         return error;
1572 }
1573
1574 static void async_suspend(void *data, async_cookie_t cookie)
1575 {
1576         struct device *dev = (struct device *)data;
1577         int error;
1578
1579         error = __device_suspend(dev, pm_transition, true);
1580         if (error) {
1581                 dpm_save_failed_dev(dev_name(dev));
1582                 pm_dev_err(dev, pm_transition, " async", error);
1583         }
1584
1585         put_device(dev);
1586 }
1587
1588 static int device_suspend(struct device *dev)
1589 {
1590         reinit_completion(&dev->power.completion);
1591
1592         if (is_async(dev)) {
1593                 get_device(dev);
1594                 async_schedule(async_suspend, dev);
1595                 return 0;
1596         }
1597
1598         return __device_suspend(dev, pm_transition, false);
1599 }
1600
1601 /**
1602  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1603  * @state: PM transition of the system being carried out.
1604  */
1605 int dpm_suspend(pm_message_t state)
1606 {
1607         ktime_t starttime = ktime_get();
1608         int error = 0;
1609
1610         trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1611         might_sleep();
1612
1613         cpufreq_suspend();
1614
1615         mutex_lock(&dpm_list_mtx);
1616         pm_transition = state;
1617         async_error = 0;
1618         while (!list_empty(&dpm_prepared_list)) {
1619                 struct device *dev = to_device(dpm_prepared_list.prev);
1620
1621                 get_device(dev);
1622                 mutex_unlock(&dpm_list_mtx);
1623
1624                 error = device_suspend(dev);
1625
1626                 mutex_lock(&dpm_list_mtx);
1627                 if (error) {
1628                         pm_dev_err(dev, state, "", error);
1629                         dpm_save_failed_dev(dev_name(dev));
1630                         put_device(dev);
1631                         break;
1632                 }
1633                 if (!list_empty(&dev->power.entry))
1634                         list_move(&dev->power.entry, &dpm_suspended_list);
1635                 put_device(dev);
1636                 if (async_error)
1637                         break;
1638         }
1639         mutex_unlock(&dpm_list_mtx);
1640         async_synchronize_full();
1641         if (!error)
1642                 error = async_error;
1643         if (error) {
1644                 suspend_stats.failed_suspend++;
1645                 dpm_save_failed_step(SUSPEND_SUSPEND);
1646         }
1647         dpm_show_time(starttime, state, error, NULL);
1648         trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1649         return error;
1650 }
1651
1652 /**
1653  * device_prepare - Prepare a device for system power transition.
1654  * @dev: Device to handle.
1655  * @state: PM transition of the system being carried out.
1656  *
1657  * Execute the ->prepare() callback(s) for given device.  No new children of the
1658  * device may be registered after this function has returned.
1659  */
1660 static int device_prepare(struct device *dev, pm_message_t state)
1661 {
1662         int (*callback)(struct device *) = NULL;
1663         int ret = 0;
1664
1665         if (dev->power.syscore)
1666                 return 0;
1667
1668         WARN_ON(dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
1669                 !pm_runtime_enabled(dev));
1670
1671         /*
1672          * If a device's parent goes into runtime suspend at the wrong time,
1673          * it won't be possible to resume the device.  To prevent this we
1674          * block runtime suspend here, during the prepare phase, and allow
1675          * it again during the complete phase.
1676          */
1677         pm_runtime_get_noresume(dev);
1678
1679         device_lock(dev);
1680
1681         dev->power.wakeup_path = device_may_wakeup(dev);
1682
1683         if (dev->power.no_pm_callbacks) {
1684                 ret = 1;        /* Let device go direct_complete */
1685                 goto unlock;
1686         }
1687
1688         if (dev->pm_domain)
1689                 callback = dev->pm_domain->ops.prepare;
1690         else if (dev->type && dev->type->pm)
1691                 callback = dev->type->pm->prepare;
1692         else if (dev->class && dev->class->pm)
1693                 callback = dev->class->pm->prepare;
1694         else if (dev->bus && dev->bus->pm)
1695                 callback = dev->bus->pm->prepare;
1696
1697         if (!callback && dev->driver && dev->driver->pm)
1698                 callback = dev->driver->pm->prepare;
1699
1700         if (callback)
1701                 ret = callback(dev);
1702
1703 unlock:
1704         device_unlock(dev);
1705
1706         if (ret < 0) {
1707                 suspend_report_result(callback, ret);
1708                 pm_runtime_put(dev);
1709                 return ret;
1710         }
1711         /*
1712          * A positive return value from ->prepare() means "this device appears
1713          * to be runtime-suspended and its state is fine, so if it really is
1714          * runtime-suspended, you can leave it in that state provided that you
1715          * will do the same thing with all of its descendants".  This only
1716          * applies to suspend transitions, however.
1717          */
1718         spin_lock_irq(&dev->power.lock);
1719         dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
1720                 pm_runtime_suspended(dev) && ret > 0 &&
1721                 !dev_pm_test_driver_flags(dev, DPM_FLAG_NEVER_SKIP);
1722         spin_unlock_irq(&dev->power.lock);
1723         return 0;
1724 }
1725
1726 /**
1727  * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1728  * @state: PM transition of the system being carried out.
1729  *
1730  * Execute the ->prepare() callback(s) for all devices.
1731  */
1732 int dpm_prepare(pm_message_t state)
1733 {
1734         int error = 0;
1735
1736         trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1737         might_sleep();
1738
1739         /*
1740          * Give a chance for the known devices to complete their probes, before
1741          * disable probing of devices. This sync point is important at least
1742          * at boot time + hibernation restore.
1743          */
1744         wait_for_device_probe();
1745         /*
1746          * It is unsafe if probing of devices will happen during suspend or
1747          * hibernation and system behavior will be unpredictable in this case.
1748          * So, let's prohibit device's probing here and defer their probes
1749          * instead. The normal behavior will be restored in dpm_complete().
1750          */
1751         device_block_probing();
1752
1753         mutex_lock(&dpm_list_mtx);
1754         while (!list_empty(&dpm_list)) {
1755                 struct device *dev = to_device(dpm_list.next);
1756
1757                 get_device(dev);
1758                 mutex_unlock(&dpm_list_mtx);
1759
1760                 trace_device_pm_callback_start(dev, "", state.event);
1761                 error = device_prepare(dev, state);
1762                 trace_device_pm_callback_end(dev, error);
1763
1764                 mutex_lock(&dpm_list_mtx);
1765                 if (error) {
1766                         if (error == -EAGAIN) {
1767                                 put_device(dev);
1768                                 error = 0;
1769                                 continue;
1770                         }
1771                         printk(KERN_INFO "PM: Device %s not prepared "
1772                                 "for power transition: code %d\n",
1773                                 dev_name(dev), error);
1774                         put_device(dev);
1775                         break;
1776                 }
1777                 dev->power.is_prepared = true;
1778                 if (!list_empty(&dev->power.entry))
1779                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
1780                 put_device(dev);
1781         }
1782         mutex_unlock(&dpm_list_mtx);
1783         trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
1784         return error;
1785 }
1786
1787 /**
1788  * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1789  * @state: PM transition of the system being carried out.
1790  *
1791  * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1792  * callbacks for them.
1793  */
1794 int dpm_suspend_start(pm_message_t state)
1795 {
1796         int error;
1797
1798         error = dpm_prepare(state);
1799         if (error) {
1800                 suspend_stats.failed_prepare++;
1801                 dpm_save_failed_step(SUSPEND_PREPARE);
1802         } else
1803                 error = dpm_suspend(state);
1804         return error;
1805 }
1806 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1807
1808 void __suspend_report_result(const char *function, void *fn, int ret)
1809 {
1810         if (ret)
1811                 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1812 }
1813 EXPORT_SYMBOL_GPL(__suspend_report_result);
1814
1815 /**
1816  * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1817  * @dev: Device to wait for.
1818  * @subordinate: Device that needs to wait for @dev.
1819  */
1820 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1821 {
1822         dpm_wait(dev, subordinate->power.async_suspend);
1823         return async_error;
1824 }
1825 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1826
1827 /**
1828  * dpm_for_each_dev - device iterator.
1829  * @data: data for the callback.
1830  * @fn: function to be called for each device.
1831  *
1832  * Iterate over devices in dpm_list, and call @fn for each device,
1833  * passing it @data.
1834  */
1835 void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
1836 {
1837         struct device *dev;
1838
1839         if (!fn)
1840                 return;
1841
1842         device_pm_lock();
1843         list_for_each_entry(dev, &dpm_list, power.entry)
1844                 fn(dev, data);
1845         device_pm_unlock();
1846 }
1847 EXPORT_SYMBOL_GPL(dpm_for_each_dev);
1848
1849 static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
1850 {
1851         if (!ops)
1852                 return true;
1853
1854         return !ops->prepare &&
1855                !ops->suspend &&
1856                !ops->suspend_late &&
1857                !ops->suspend_noirq &&
1858                !ops->resume_noirq &&
1859                !ops->resume_early &&
1860                !ops->resume &&
1861                !ops->complete;
1862 }
1863
1864 void device_pm_check_callbacks(struct device *dev)
1865 {
1866         spin_lock_irq(&dev->power.lock);
1867         dev->power.no_pm_callbacks =
1868                 (!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
1869                  !dev->bus->suspend && !dev->bus->resume)) &&
1870                 (!dev->class || pm_ops_is_empty(dev->class->pm)) &&
1871                 (!dev->type || pm_ops_is_empty(dev->type->pm)) &&
1872                 (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
1873                 (!dev->driver || (pm_ops_is_empty(dev->driver->pm) &&
1874                  !dev->driver->suspend && !dev->driver->resume));
1875         spin_unlock_irq(&dev->power.lock);
1876 }
1877
1878 bool dev_pm_smart_suspend_and_suspended(struct device *dev)
1879 {
1880         return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
1881                 pm_runtime_status_suspended(dev);
1882 }