Pileus Git - ~andy/linux/blob - 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/resume-trace.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/sched.h>
  29 #include <linux/async.h>
  30 #include <linux/suspend.h>
  31 #include <trace/events/power.h>
  32 #include <linux/cpuidle.h>
  33 #include "../base.h"
  34 #include "power.h"
  35
  36 typedef int (*pm_callback_t)(struct device *);
  37
  38 /*
  39  * The entries in the dpm_list list are in a depth first order, simply
  40  * because children are guaranteed to be discovered after parents, and
  41  * are inserted at the back of the list on discovery.
  42  *
  43  * Since device_pm_add() may be called with a device lock held,
  44  * we must never try to acquire a device lock while holding
  45  * dpm_list_mutex.
  46  */
  47
  48 LIST_HEAD(dpm_list);
  49 static LIST_HEAD(dpm_prepared_list);
  50 static LIST_HEAD(dpm_suspended_list);
  51 static LIST_HEAD(dpm_late_early_list);
  52 static LIST_HEAD(dpm_noirq_list);
  53
  54 struct suspend_stats suspend_stats;
  55 static DEFINE_MUTEX(dpm_list_mtx);
  56 static pm_message_t pm_transition;
  57
  58 static int async_error;
  59
  60 static char *pm_verb(int event)
  61 {
  62         switch (event) {
  63         case PM_EVENT_SUSPEND:
  64                 return "suspend";
  65         case PM_EVENT_RESUME:
  66                 return "resume";
  67         case PM_EVENT_FREEZE:
  68                 return "freeze";
  69         case PM_EVENT_QUIESCE:
  70                 return "quiesce";
  71         case PM_EVENT_HIBERNATE:
  72                 return "hibernate";
  73         case PM_EVENT_THAW:
  74                 return "thaw";
  75         case PM_EVENT_RESTORE:
  76                 return "restore";
  77         case PM_EVENT_RECOVER:
  78                 return "recover";
  79         default:
  80                 return "(unknown PM event)";
  81         }
  82 }
  83
  84 /**
  85  * device_pm_sleep_init - Initialize system suspend-related device fields.
  86  * @dev: Device object being initialized.
  87  */
  88 void device_pm_sleep_init(struct device *dev)
  89 {
  90         dev->power.is_prepared = false;
  91         dev->power.is_suspended = false;
  92         init_completion(&dev->power.completion);
  93         complete_all(&dev->power.completion);
  94         dev->power.wakeup = NULL;
  95         INIT_LIST_HEAD(&dev->power.entry);
  96 }
  97
  98 /**
  99  * device_pm_lock - Lock the list of active devices used by the PM core.
 100  */
 101 void device_pm_lock(void)
 102 {
 103         mutex_lock(&dpm_list_mtx);
 104 }
 105
 106 /**
 107  * device_pm_unlock - Unlock the list of active devices used by the PM core.
 108  */
 109 void device_pm_unlock(void)
 110 {
 111         mutex_unlock(&dpm_list_mtx);
 112 }
 113
 114 /**
 115  * device_pm_add - Add a device to the PM core's list of active devices.
 116  * @dev: Device to add to the list.
 117  */
 118 void device_pm_add(struct device *dev)
 119 {
 120         pr_debug("PM: Adding info for %s:%s\n",
 121                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 122         mutex_lock(&dpm_list_mtx);
 123         if (dev->parent && dev->parent->power.is_prepared)
 124                 dev_warn(dev, "parent %s should not be sleeping\n",
 125                         dev_name(dev->parent));
 126         list_add_tail(&dev->power.entry, &dpm_list);
 127         mutex_unlock(&dpm_list_mtx);
 128 }
 129
 130 /**
 131  * device_pm_remove - Remove a device from the PM core's list of active devices.
 132  * @dev: Device to be removed from the list.
 133  */
 134 void device_pm_remove(struct device *dev)
 135 {
 136         pr_debug("PM: Removing info for %s:%s\n",
 137                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 138         complete_all(&dev->power.completion);
 139         mutex_lock(&dpm_list_mtx);
 140         list_del_init(&dev->power.entry);
 141         mutex_unlock(&dpm_list_mtx);
 142         device_wakeup_disable(dev);
 143         pm_runtime_remove(dev);
 144 }
 145
 146 /**
 147  * device_pm_move_before - Move device in the PM core's list of active devices.
 148  * @deva: Device to move in dpm_list.
 149  * @devb: Device @deva should come before.
 150  */
 151 void device_pm_move_before(struct device *deva, struct device *devb)
 152 {
 153         pr_debug("PM: Moving %s:%s before %s:%s\n",
 154                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 155                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 156         /* Delete deva from dpm_list and reinsert before devb. */
 157         list_move_tail(&deva->power.entry, &devb->power.entry);
 158 }
 159
 160 /**
 161  * device_pm_move_after - Move device in the PM core's list of active devices.
 162  * @deva: Device to move in dpm_list.
 163  * @devb: Device @deva should come after.
 164  */
 165 void device_pm_move_after(struct device *deva, struct device *devb)
 166 {
 167         pr_debug("PM: Moving %s:%s after %s:%s\n",
 168                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 169                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 170         /* Delete deva from dpm_list and reinsert after devb. */
 171         list_move(&deva->power.entry, &devb->power.entry);
 172 }
 173
 174 /**
 175  * device_pm_move_last - Move device to end of the PM core's list of devices.
 176  * @dev: Device to move in dpm_list.
 177  */
 178 void device_pm_move_last(struct device *dev)
 179 {
 180         pr_debug("PM: Moving %s:%s to end of list\n",
 181                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 182         list_move_tail(&dev->power.entry, &dpm_list);
 183 }
 184
 185 static ktime_t initcall_debug_start(struct device *dev)
 186 {
 187         ktime_t calltime = ktime_set(0, 0);
 188
 189         if (pm_print_times_enabled) {
 190                 pr_info("calling  %s+ @ %i, parent: %s\n",
 191                         dev_name(dev), task_pid_nr(current),
 192                         dev->parent ? dev_name(dev->parent) : "none");
 193                 calltime = ktime_get();
 194         }
 195
 196         return calltime;
 197 }
 198
 199 static void initcall_debug_report(struct device *dev, ktime_t calltime,
 200                                   int error, pm_message_t state, char *info)
 201 {
 202         ktime_t rettime;
 203         s64 nsecs;
 204
 205         rettime = ktime_get();
 206         nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime));
 207
 208         if (pm_print_times_enabled) {
 209                 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
 210                         error, (unsigned long long)nsecs >> 10);
 211         }
 212
 213         trace_device_pm_report_time(dev, info, nsecs, pm_verb(state.event),
 214                                     error);
 215 }
 216
 217 /**
 218  * dpm_wait - Wait for a PM operation to complete.
 219  * @dev: Device to wait for.
 220  * @async: If unset, wait only if the device's power.async_suspend flag is set.
 221  */
 222 static void dpm_wait(struct device *dev, bool async)
 223 {
 224         if (!dev)
 225                 return;
 226
 227         if (async || (pm_async_enabled && dev->power.async_suspend))
 228                 wait_for_completion(&dev->power.completion);
 229 }
 230
 231 static int dpm_wait_fn(struct device *dev, void *async_ptr)
 232 {
 233         dpm_wait(dev, *((bool *)async_ptr));
 234         return 0;
 235 }
 236
 237 static void dpm_wait_for_children(struct device *dev, bool async)
 238 {
 239        device_for_each_child(dev, &async, dpm_wait_fn);
 240 }
 241
 242 /**
 243  * pm_op - Return the PM operation appropriate for given PM event.
 244  * @ops: PM operations to choose from.
 245  * @state: PM transition of the system being carried out.
 246  */
 247 static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
 248 {
 249         switch (state.event) {
 250 #ifdef CONFIG_SUSPEND
 251         case PM_EVENT_SUSPEND:
 252                 return ops->suspend;
 253         case PM_EVENT_RESUME:
 254                 return ops->resume;
 255 #endif /* CONFIG_SUSPEND */
 256 #ifdef CONFIG_HIBERNATE_CALLBACKS
 257         case PM_EVENT_FREEZE:
 258         case PM_EVENT_QUIESCE:
 259                 return ops->freeze;
 260         case PM_EVENT_HIBERNATE:
 261                 return ops->poweroff;
 262         case PM_EVENT_THAW:
 263         case PM_EVENT_RECOVER:
 264                 return ops->thaw;
 265                 break;
 266         case PM_EVENT_RESTORE:
 267                 return ops->restore;
 268 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 269         }
 270
 271         return NULL;
 272 }
 273
 274 /**
 275  * pm_late_early_op - Return the PM operation appropriate for given PM event.
 276  * @ops: PM operations to choose from.
 277  * @state: PM transition of the system being carried out.
 278  *
 279  * Runtime PM is disabled for @dev while this function is being executed.
 280  */
 281 static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
 282                                       pm_message_t state)
 283 {
 284         switch (state.event) {
 285 #ifdef CONFIG_SUSPEND
 286         case PM_EVENT_SUSPEND:
 287                 return ops->suspend_late;
 288         case PM_EVENT_RESUME:
 289                 return ops->resume_early;
 290 #endif /* CONFIG_SUSPEND */
 291 #ifdef CONFIG_HIBERNATE_CALLBACKS
 292         case PM_EVENT_FREEZE:
 293         case PM_EVENT_QUIESCE:
 294                 return ops->freeze_late;
 295         case PM_EVENT_HIBERNATE:
 296                 return ops->poweroff_late;
 297         case PM_EVENT_THAW:
 298         case PM_EVENT_RECOVER:
 299                 return ops->thaw_early;
 300         case PM_EVENT_RESTORE:
 301                 return ops->restore_early;
 302 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 303         }
 304
 305         return NULL;
 306 }
 307
 308 /**
 309  * pm_noirq_op - Return the PM operation appropriate for given PM event.
 310  * @ops: PM operations to choose from.
 311  * @state: PM transition of the system being carried out.
 312  *
 313  * The driver of @dev will not receive interrupts while this function is being
 314  * executed.
 315  */
 316 static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
 317 {
 318         switch (state.event) {
 319 #ifdef CONFIG_SUSPEND
 320         case PM_EVENT_SUSPEND:
 321                 return ops->suspend_noirq;
 322         case PM_EVENT_RESUME:
 323                 return ops->resume_noirq;
 324 #endif /* CONFIG_SUSPEND */
 325 #ifdef CONFIG_HIBERNATE_CALLBACKS
 326         case PM_EVENT_FREEZE:
 327         case PM_EVENT_QUIESCE:
 328                 return ops->freeze_noirq;
 329         case PM_EVENT_HIBERNATE:
 330                 return ops->poweroff_noirq;
 331         case PM_EVENT_THAW:
 332         case PM_EVENT_RECOVER:
 333                 return ops->thaw_noirq;
 334         case PM_EVENT_RESTORE:
 335                 return ops->restore_noirq;
 336 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 337         }
 338
 339         return NULL;
 340 }
 341
 342 static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
 343 {
 344         dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
 345                 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
 346                 ", may wakeup" : "");
 347 }
 348
 349 static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
 350                         int error)
 351 {
 352         printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
 353                 dev_name(dev), pm_verb(state.event), info, error);
 354 }
 355
 356 static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
 357 {
 358         ktime_t calltime;
 359         u64 usecs64;
 360         int usecs;
 361
 362         calltime = ktime_get();
 363         usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
 364         do_div(usecs64, NSEC_PER_USEC);
 365         usecs = usecs64;
 366         if (usecs == 0)
 367                 usecs = 1;
 368         pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
 369                 info ?: "", info ? " " : "", pm_verb(state.event),
 370                 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
 371 }
 372
 373 static int dpm_run_callback(pm_callback_t cb, struct device *dev,
 374                             pm_message_t state, char *info)
 375 {
 376         ktime_t calltime;
 377         int error;
 378
 379         if (!cb)
 380                 return 0;
 381
 382         calltime = initcall_debug_start(dev);
 383
 384         pm_dev_dbg(dev, state, info);
 385         error = cb(dev);
 386         suspend_report_result(cb, error);
 387
 388         initcall_debug_report(dev, calltime, error, state, info);
 389
 390         return error;
 391 }
 392
 393 /*------------------------- Resume routines -------------------------*/
 394
 395 /**
 396  * device_resume_noirq - Execute an "early resume" callback for given device.
 397  * @dev: Device to handle.
 398  * @state: PM transition of the system being carried out.
 399  *
 400  * The driver of @dev will not receive interrupts while this function is being
 401  * executed.
 402  */
 403 static int device_resume_noirq(struct device *dev, pm_message_t state)
 404 {
 405         pm_callback_t callback = NULL;
 406         char *info = NULL;
 407         int error = 0;
 408
 409         TRACE_DEVICE(dev);
 410         TRACE_RESUME(0);
 411
 412         if (dev->power.syscore)
 413                 goto Out;
 414
 415         if (dev->pm_domain) {
 416                 info = "noirq power domain ";
 417                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
 418         } else if (dev->type && dev->type->pm) {
 419                 info = "noirq type ";
 420                 callback = pm_noirq_op(dev->type->pm, state);
 421         } else if (dev->class && dev->class->pm) {
 422                 info = "noirq class ";
 423                 callback = pm_noirq_op(dev->class->pm, state);
 424         } else if (dev->bus && dev->bus->pm) {
 425                 info = "noirq bus ";
 426                 callback = pm_noirq_op(dev->bus->pm, state);
 427         }
 428
 429         if (!callback && dev->driver && dev->driver->pm) {
 430                 info = "noirq driver ";
 431                 callback = pm_noirq_op(dev->driver->pm, state);
 432         }
 433
 434         error = dpm_run_callback(callback, dev, state, info);
 435
 436  Out:
 437         TRACE_RESUME(error);
 438         return error;
 439 }
 440
 441 /**
 442  * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
 443  * @state: PM transition of the system being carried out.
 444  *
 445  * Call the "noirq" resume handlers for all devices in dpm_noirq_list and
 446  * enable device drivers to receive interrupts.
 447  */
 448 static void dpm_resume_noirq(pm_message_t state)
 449 {
 450         ktime_t starttime = ktime_get();
 451
 452         mutex_lock(&dpm_list_mtx);
 453         while (!list_empty(&dpm_noirq_list)) {
 454                 struct device *dev = to_device(dpm_noirq_list.next);
 455                 int error;
 456
 457                 get_device(dev);
 458                 list_move_tail(&dev->power.entry, &dpm_late_early_list);
 459                 mutex_unlock(&dpm_list_mtx);
 460
 461                 error = device_resume_noirq(dev, state);
 462                 if (error) {
 463                         suspend_stats.failed_resume_noirq++;
 464                         dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
 465                         dpm_save_failed_dev(dev_name(dev));
 466                         pm_dev_err(dev, state, " noirq", error);
 467                 }
 468
 469                 mutex_lock(&dpm_list_mtx);
 470                 put_device(dev);
 471         }
 472         mutex_unlock(&dpm_list_mtx);
 473         dpm_show_time(starttime, state, "noirq");
 474         resume_device_irqs();
 475         cpuidle_resume();
 476 }
 477
 478 /**
 479  * device_resume_early - Execute an "early resume" callback for given device.
 480  * @dev: Device to handle.
 481  * @state: PM transition of the system being carried out.
 482  *
 483  * Runtime PM is disabled for @dev while this function is being executed.
 484  */
 485 static int device_resume_early(struct device *dev, pm_message_t state)
 486 {
 487         pm_callback_t callback = NULL;
 488         char *info = NULL;
 489         int error = 0;
 490
 491         TRACE_DEVICE(dev);
 492         TRACE_RESUME(0);
 493
 494         if (dev->power.syscore)
 495                 goto Out;
 496
 497         if (dev->pm_domain) {
 498                 info = "early power domain ";
 499                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
 500         } else if (dev->type && dev->type->pm) {
 501                 info = "early type ";
 502                 callback = pm_late_early_op(dev->type->pm, state);
 503         } else if (dev->class && dev->class->pm) {
 504                 info = "early class ";
 505                 callback = pm_late_early_op(dev->class->pm, state);
 506         } else if (dev->bus && dev->bus->pm) {
 507                 info = "early bus ";
 508                 callback = pm_late_early_op(dev->bus->pm, state);
 509         }
 510
 511         if (!callback && dev->driver && dev->driver->pm) {
 512                 info = "early driver ";
 513                 callback = pm_late_early_op(dev->driver->pm, state);
 514         }
 515
 516         error = dpm_run_callback(callback, dev, state, info);
 517
 518  Out:
 519         TRACE_RESUME(error);
 520
 521         pm_runtime_enable(dev);
 522         return error;
 523 }
 524
 525 /**
 526  * dpm_resume_early - Execute "early resume" callbacks for all devices.
 527  * @state: PM transition of the system being carried out.
 528  */
 529 static void dpm_resume_early(pm_message_t state)
 530 {
 531         ktime_t starttime = ktime_get();
 532
 533         mutex_lock(&dpm_list_mtx);
 534         while (!list_empty(&dpm_late_early_list)) {
 535                 struct device *dev = to_device(dpm_late_early_list.next);
 536                 int error;
 537
 538                 get_device(dev);
 539                 list_move_tail(&dev->power.entry, &dpm_suspended_list);
 540                 mutex_unlock(&dpm_list_mtx);
 541
 542                 error = device_resume_early(dev, state);
 543                 if (error) {
 544                         suspend_stats.failed_resume_early++;
 545                         dpm_save_failed_step(SUSPEND_RESUME_EARLY);
 546                         dpm_save_failed_dev(dev_name(dev));
 547                         pm_dev_err(dev, state, " early", error);
 548                 }
 549
 550                 mutex_lock(&dpm_list_mtx);
 551                 put_device(dev);
 552         }
 553         mutex_unlock(&dpm_list_mtx);
 554         dpm_show_time(starttime, state, "early");
 555 }
 556
 557 /**
 558  * dpm_resume_start - Execute "noirq" and "early" device callbacks.
 559  * @state: PM transition of the system being carried out.
 560  */
 561 void dpm_resume_start(pm_message_t state)
 562 {
 563         dpm_resume_noirq(state);
 564         dpm_resume_early(state);
 565 }
 566 EXPORT_SYMBOL_GPL(dpm_resume_start);
 567
 568 /**
 569  * device_resume - Execute "resume" callbacks for given device.
 570  * @dev: Device to handle.
 571  * @state: PM transition of the system being carried out.
 572  * @async: If true, the device is being resumed asynchronously.
 573  */
 574 static int device_resume(struct device *dev, pm_message_t state, bool async)
 575 {
 576         pm_callback_t callback = NULL;
 577         char *info = NULL;
 578         int error = 0;
 579
 580         TRACE_DEVICE(dev);
 581         TRACE_RESUME(0);
 582
 583         if (dev->power.syscore)
 584                 goto Complete;
 585
 586         dpm_wait(dev->parent, async);
 587         device_lock(dev);
 588
 589         /*
 590          * This is a fib.  But we'll allow new children to be added below
 591          * a resumed device, even if the device hasn't been completed yet.
 592          */
 593         dev->power.is_prepared = false;
 594
 595         if (!dev->power.is_suspended)
 596                 goto Unlock;
 597
 598         if (dev->pm_domain) {
 599                 info = "power domain ";
 600                 callback = pm_op(&dev->pm_domain->ops, state);
 601                 goto Driver;
 602         }
 603
 604         if (dev->type && dev->type->pm) {
 605                 info = "type ";
 606                 callback = pm_op(dev->type->pm, state);
 607                 goto Driver;
 608         }
 609
 610         if (dev->class) {
 611                 if (dev->class->pm) {
 612                         info = "class ";
 613                         callback = pm_op(dev->class->pm, state);
 614                         goto Driver;
 615                 } else if (dev->class->resume) {
 616                         info = "legacy class ";
 617                         callback = dev->class->resume;
 618                         goto End;
 619                 }
 620         }
 621
 622         if (dev->bus) {
 623                 if (dev->bus->pm) {
 624                         info = "bus ";
 625                         callback = pm_op(dev->bus->pm, state);
 626                 } else if (dev->bus->resume) {
 627                         info = "legacy bus ";
 628                         callback = dev->bus->resume;
 629                         goto End;
 630                 }
 631         }
 632
 633  Driver:
 634         if (!callback && dev->driver && dev->driver->pm) {
 635                 info = "driver ";
 636                 callback = pm_op(dev->driver->pm, state);
 637         }
 638
 639  End:
 640         error = dpm_run_callback(callback, dev, state, info);
 641         dev->power.is_suspended = false;
 642
 643  Unlock:
 644         device_unlock(dev);
 645
 646  Complete:
 647         complete_all(&dev->power.completion);
 648
 649         TRACE_RESUME(error);
 650
 651         return error;
 652 }
 653
 654 static void async_resume(void *data, async_cookie_t cookie)
 655 {
 656         struct device *dev = (struct device *)data;
 657         int error;
 658
 659         error = device_resume(dev, pm_transition, true);
 660         if (error)
 661                 pm_dev_err(dev, pm_transition, " async", error);
 662         put_device(dev);
 663 }
 664
 665 static bool is_async(struct device *dev)
 666 {
 667         return dev->power.async_suspend && pm_async_enabled
 668                 && !pm_trace_is_enabled();
 669 }
 670
 671 /**
 672  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
 673  * @state: PM transition of the system being carried out.
 674  *
 675  * Execute the appropriate "resume" callback for all devices whose status
 676  * indicates that they are suspended.
 677  */
 678 void dpm_resume(pm_message_t state)
 679 {
 680         struct device *dev;
 681         ktime_t starttime = ktime_get();
 682
 683         might_sleep();
 684
 685         mutex_lock(&dpm_list_mtx);
 686         pm_transition = state;
 687         async_error = 0;
 688
 689         list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
 690                 INIT_COMPLETION(dev->power.completion);
 691                 if (is_async(dev)) {
 692                         get_device(dev);
 693                         async_schedule(async_resume, dev);
 694                 }
 695         }
 696
 697         while (!list_empty(&dpm_suspended_list)) {
 698                 dev = to_device(dpm_suspended_list.next);
 699                 get_device(dev);
 700                 if (!is_async(dev)) {
 701                         int error;
 702
 703                         mutex_unlock(&dpm_list_mtx);
 704
 705                         error = device_resume(dev, state, false);
 706                         if (error) {
 707                                 suspend_stats.failed_resume++;
 708                                 dpm_save_failed_step(SUSPEND_RESUME);
 709                                 dpm_save_failed_dev(dev_name(dev));
 710                                 pm_dev_err(dev, state, "", error);
 711                         }
 712
 713                         mutex_lock(&dpm_list_mtx);
 714                 }
 715                 if (!list_empty(&dev->power.entry))
 716                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
 717                 put_device(dev);
 718         }
 719         mutex_unlock(&dpm_list_mtx);
 720         async_synchronize_full();
 721         dpm_show_time(starttime, state, NULL);
 722 }
 723
 724 /**
 725  * device_complete - Complete a PM transition for given device.
 726  * @dev: Device to handle.
 727  * @state: PM transition of the system being carried out.
 728  */
 729 static void device_complete(struct device *dev, pm_message_t state)
 730 {
 731         void (*callback)(struct device *) = NULL;
 732         char *info = NULL;
 733
 734         if (dev->power.syscore)
 735                 return;
 736
 737         device_lock(dev);
 738
 739         if (dev->pm_domain) {
 740                 info = "completing power domain ";
 741                 callback = dev->pm_domain->ops.complete;
 742         } else if (dev->type && dev->type->pm) {
 743                 info = "completing type ";
 744                 callback = dev->type->pm->complete;
 745         } else if (dev->class && dev->class->pm) {
 746                 info = "completing class ";
 747                 callback = dev->class->pm->complete;
 748         } else if (dev->bus && dev->bus->pm) {
 749                 info = "completing bus ";
 750                 callback = dev->bus->pm->complete;
 751         }
 752
 753         if (!callback && dev->driver && dev->driver->pm) {
 754                 info = "completing driver ";
 755                 callback = dev->driver->pm->complete;
 756         }
 757
 758         if (callback) {
 759                 pm_dev_dbg(dev, state, info);
 760                 callback(dev);
 761         }
 762
 763         device_unlock(dev);
 764
 765         pm_runtime_put(dev);
 766 }
 767
 768 /**
 769  * dpm_complete - Complete a PM transition for all non-sysdev devices.
 770  * @state: PM transition of the system being carried out.
 771  *
 772  * Execute the ->complete() callbacks for all devices whose PM status is not
 773  * DPM_ON (this allows new devices to be registered).
 774  */
 775 void dpm_complete(pm_message_t state)
 776 {
 777         struct list_head list;
 778
 779         might_sleep();
 780
 781         INIT_LIST_HEAD(&list);
 782         mutex_lock(&dpm_list_mtx);
 783         while (!list_empty(&dpm_prepared_list)) {
 784                 struct device *dev = to_device(dpm_prepared_list.prev);
 785
 786                 get_device(dev);
 787                 dev->power.is_prepared = false;
 788                 list_move(&dev->power.entry, &list);
 789                 mutex_unlock(&dpm_list_mtx);
 790
 791                 device_complete(dev, state);
 792
 793                 mutex_lock(&dpm_list_mtx);
 794                 put_device(dev);
 795         }
 796         list_splice(&list, &dpm_list);
 797         mutex_unlock(&dpm_list_mtx);
 798 }
 799
 800 /**
 801  * dpm_resume_end - Execute "resume" callbacks and complete system transition.
 802  * @state: PM transition of the system being carried out.
 803  *
 804  * Execute "resume" callbacks for all devices and complete the PM transition of
 805  * the system.
 806  */
 807 void dpm_resume_end(pm_message_t state)
 808 {
 809         dpm_resume(state);
 810         dpm_complete(state);
 811 }
 812 EXPORT_SYMBOL_GPL(dpm_resume_end);
 813
 814
 815 /*------------------------- Suspend routines -------------------------*/
 816
 817 /**
 818  * resume_event - Return a "resume" message for given "suspend" sleep state.
 819  * @sleep_state: PM message representing a sleep state.
 820  *
 821  * Return a PM message representing the resume event corresponding to given
 822  * sleep state.
 823  */
 824 static pm_message_t resume_event(pm_message_t sleep_state)
 825 {
 826         switch (sleep_state.event) {
 827         case PM_EVENT_SUSPEND:
 828                 return PMSG_RESUME;
 829         case PM_EVENT_FREEZE:
 830         case PM_EVENT_QUIESCE:
 831                 return PMSG_RECOVER;
 832         case PM_EVENT_HIBERNATE:
 833                 return PMSG_RESTORE;
 834         }
 835         return PMSG_ON;
 836 }
 837
 838 /**
 839  * device_suspend_noirq - Execute a "late suspend" callback for given device.
 840  * @dev: Device to handle.
 841  * @state: PM transition of the system being carried out.
 842  *
 843  * The driver of @dev will not receive interrupts while this function is being
 844  * executed.
 845  */
 846 static int device_suspend_noirq(struct device *dev, pm_message_t state)
 847 {
 848         pm_callback_t callback = NULL;
 849         char *info = NULL;
 850
 851         if (dev->power.syscore)
 852                 return 0;
 853
 854         if (dev->pm_domain) {
 855                 info = "noirq power domain ";
 856                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
 857         } else if (dev->type && dev->type->pm) {
 858                 info = "noirq type ";
 859                 callback = pm_noirq_op(dev->type->pm, state);
 860         } else if (dev->class && dev->class->pm) {
 861                 info = "noirq class ";
 862                 callback = pm_noirq_op(dev->class->pm, state);
 863         } else if (dev->bus && dev->bus->pm) {
 864                 info = "noirq bus ";
 865                 callback = pm_noirq_op(dev->bus->pm, state);
 866         }
 867
 868         if (!callback && dev->driver && dev->driver->pm) {
 869                 info = "noirq driver ";
 870                 callback = pm_noirq_op(dev->driver->pm, state);
 871         }
 872
 873         return dpm_run_callback(callback, dev, state, info);
 874 }
 875
 876 /**
 877  * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
 878  * @state: PM transition of the system being carried out.
 879  *
 880  * Prevent device drivers from receiving interrupts and call the "noirq" suspend
 881  * handlers for all non-sysdev devices.
 882  */
 883 static int dpm_suspend_noirq(pm_message_t state)
 884 {
 885         ktime_t starttime = ktime_get();
 886         int error = 0;
 887
 888         cpuidle_pause();
 889         suspend_device_irqs();
 890         mutex_lock(&dpm_list_mtx);
 891         while (!list_empty(&dpm_late_early_list)) {
 892                 struct device *dev = to_device(dpm_late_early_list.prev);
 893
 894                 get_device(dev);
 895                 mutex_unlock(&dpm_list_mtx);
 896
 897                 error = device_suspend_noirq(dev, state);
 898
 899                 mutex_lock(&dpm_list_mtx);
 900                 if (error) {
 901                         pm_dev_err(dev, state, " noirq", error);
 902                         suspend_stats.failed_suspend_noirq++;
 903                         dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
 904                         dpm_save_failed_dev(dev_name(dev));
 905                         put_device(dev);
 906                         break;
 907                 }
 908                 if (!list_empty(&dev->power.entry))
 909                         list_move(&dev->power.entry, &dpm_noirq_list);
 910                 put_device(dev);
 911
 912                 if (pm_wakeup_pending()) {
 913                         error = -EBUSY;
 914                         break;
 915                 }
 916         }
 917         mutex_unlock(&dpm_list_mtx);
 918         if (error)
 919                 dpm_resume_noirq(resume_event(state));
 920         else
 921                 dpm_show_time(starttime, state, "noirq");
 922         return error;
 923 }
 924
 925 /**
 926  * device_suspend_late - Execute a "late suspend" callback for given device.
 927  * @dev: Device to handle.
 928  * @state: PM transition of the system being carried out.
 929  *
 930  * Runtime PM is disabled for @dev while this function is being executed.
 931  */
 932 static int device_suspend_late(struct device *dev, pm_message_t state)
 933 {
 934         pm_callback_t callback = NULL;
 935         char *info = NULL;
 936
 937         __pm_runtime_disable(dev, false);
 938
 939         if (dev->power.syscore)
 940                 return 0;
 941
 942         if (dev->pm_domain) {
 943                 info = "late power domain ";
 944                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
 945         } else if (dev->type && dev->type->pm) {
 946                 info = "late type ";
 947                 callback = pm_late_early_op(dev->type->pm, state);
 948         } else if (dev->class && dev->class->pm) {
 949                 info = "late class ";
 950                 callback = pm_late_early_op(dev->class->pm, state);
 951         } else if (dev->bus && dev->bus->pm) {
 952                 info = "late bus ";
 953                 callback = pm_late_early_op(dev->bus->pm, state);
 954         }
 955
 956         if (!callback && dev->driver && dev->driver->pm) {
 957                 info = "late driver ";
 958                 callback = pm_late_early_op(dev->driver->pm, state);
 959         }
 960
 961         return dpm_run_callback(callback, dev, state, info);
 962 }
 963
 964 /**
 965  * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
 966  * @state: PM transition of the system being carried out.
 967  */
 968 static int dpm_suspend_late(pm_message_t state)
 969 {
 970         ktime_t starttime = ktime_get();
 971         int error = 0;
 972
 973         mutex_lock(&dpm_list_mtx);
 974         while (!list_empty(&dpm_suspended_list)) {
 975                 struct device *dev = to_device(dpm_suspended_list.prev);
 976
 977                 get_device(dev);
 978                 mutex_unlock(&dpm_list_mtx);
 979
 980                 error = device_suspend_late(dev, state);
 981
 982                 mutex_lock(&dpm_list_mtx);
 983                 if (error) {
 984                         pm_dev_err(dev, state, " late", error);
 985                         suspend_stats.failed_suspend_late++;
 986                         dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
 987                         dpm_save_failed_dev(dev_name(dev));
 988                         put_device(dev);
 989                         break;
 990                 }
 991                 if (!list_empty(&dev->power.entry))
 992                         list_move(&dev->power.entry, &dpm_late_early_list);
 993                 put_device(dev);
 994
 995                 if (pm_wakeup_pending()) {
 996                         error = -EBUSY;
 997                         break;
 998                 }
 999         }
1000         mutex_unlock(&dpm_list_mtx);
1001         if (error)
1002                 dpm_resume_early(resume_event(state));
1003         else
1004                 dpm_show_time(starttime, state, "late");
1005
1006         return error;
1007 }
1008
1009 /**
1010  * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1011  * @state: PM transition of the system being carried out.
1012  */
1013 int dpm_suspend_end(pm_message_t state)
1014 {
1015         int error = dpm_suspend_late(state);
1016         if (error)
1017                 return error;
1018
1019         error = dpm_suspend_noirq(state);
1020         if (error) {
1021                 dpm_resume_early(resume_event(state));
1022                 return error;
1023         }
1024
1025         return 0;
1026 }
1027 EXPORT_SYMBOL_GPL(dpm_suspend_end);
1028
1029 /**
1030  * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1031  * @dev: Device to suspend.
1032  * @state: PM transition of the system being carried out.
1033  * @cb: Suspend callback to execute.
1034  */
1035 static int legacy_suspend(struct device *dev, pm_message_t state,
1036                           int (*cb)(struct device *dev, pm_message_t state),
1037                           char *info)
1038 {
1039         int error;
1040         ktime_t calltime;
1041
1042         calltime = initcall_debug_start(dev);
1043
1044         error = cb(dev, state);
1045         suspend_report_result(cb, error);
1046
1047         initcall_debug_report(dev, calltime, error, state, info);
1048
1049         return error;
1050 }
1051
1052 /**
1053  * device_suspend - Execute "suspend" callbacks for given device.
1054  * @dev: Device to handle.
1055  * @state: PM transition of the system being carried out.
1056  * @async: If true, the device is being suspended asynchronously.
1057  */
1058 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1059 {
1060         pm_callback_t callback = NULL;
1061         char *info = NULL;
1062         int error = 0;
1063
1064         dpm_wait_for_children(dev, async);
1065
1066         if (async_error)
1067                 goto Complete;
1068
1069         /*
1070          * If a device configured to wake up the system from sleep states
1071          * has been suspended at run time and there's a resume request pending
1072          * for it, this is equivalent to the device signaling wakeup, so the
1073          * system suspend operation should be aborted.
1074          */
1075         if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1076                 pm_wakeup_event(dev, 0);
1077
1078         if (pm_wakeup_pending()) {
1079                 async_error = -EBUSY;
1080                 goto Complete;
1081         }
1082
1083         if (dev->power.syscore)
1084                 goto Complete;
1085
1086         device_lock(dev);
1087
1088         if (dev->pm_domain) {
1089                 info = "power domain ";
1090                 callback = pm_op(&dev->pm_domain->ops, state);
1091                 goto Run;
1092         }
1093
1094         if (dev->type && dev->type->pm) {
1095                 info = "type ";
1096                 callback = pm_op(dev->type->pm, state);
1097                 goto Run;
1098         }
1099
1100         if (dev->class) {
1101                 if (dev->class->pm) {
1102                         info = "class ";
1103                         callback = pm_op(dev->class->pm, state);
1104                         goto Run;
1105                 } else if (dev->class->suspend) {
1106                         pm_dev_dbg(dev, state, "legacy class ");
1107                         error = legacy_suspend(dev, state, dev->class->suspend,
1108                                                 "legacy class ");
1109                         goto End;
1110                 }
1111         }
1112
1113         if (dev->bus) {
1114                 if (dev->bus->pm) {
1115                         info = "bus ";
1116                         callback = pm_op(dev->bus->pm, state);
1117                 } else if (dev->bus->suspend) {
1118                         pm_dev_dbg(dev, state, "legacy bus ");
1119                         error = legacy_suspend(dev, state, dev->bus->suspend,
1120                                                 "legacy bus ");
1121                         goto End;
1122                 }
1123         }
1124
1125  Run:
1126         if (!callback && dev->driver && dev->driver->pm) {
1127                 info = "driver ";
1128                 callback = pm_op(dev->driver->pm, state);
1129         }
1130
1131         error = dpm_run_callback(callback, dev, state, info);
1132
1133  End:
1134         if (!error) {
1135                 dev->power.is_suspended = true;
1136                 if (dev->power.wakeup_path
1137                     && dev->parent && !dev->parent->power.ignore_children)
1138                         dev->parent->power.wakeup_path = true;
1139         }
1140
1141         device_unlock(dev);
1142
1143  Complete:
1144         complete_all(&dev->power.completion);
1145         if (error)
1146                 async_error = error;
1147
1148         return error;
1149 }
1150
1151 static void async_suspend(void *data, async_cookie_t cookie)
1152 {
1153         struct device *dev = (struct device *)data;
1154         int error;
1155
1156         error = __device_suspend(dev, pm_transition, true);
1157         if (error) {
1158                 dpm_save_failed_dev(dev_name(dev));
1159                 pm_dev_err(dev, pm_transition, " async", error);
1160         }
1161
1162         put_device(dev);
1163 }
1164
1165 static int device_suspend(struct device *dev)
1166 {
1167         INIT_COMPLETION(dev->power.completion);
1168
1169         if (pm_async_enabled && dev->power.async_suspend) {
1170                 get_device(dev);
1171                 async_schedule(async_suspend, dev);
1172                 return 0;
1173         }
1174
1175         return __device_suspend(dev, pm_transition, false);
1176 }
1177
1178 /**
1179  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1180  * @state: PM transition of the system being carried out.
1181  */
1182 int dpm_suspend(pm_message_t state)
1183 {
1184         ktime_t starttime = ktime_get();
1185         int error = 0;
1186
1187         might_sleep();
1188
1189         mutex_lock(&dpm_list_mtx);
1190         pm_transition = state;
1191         async_error = 0;
1192         while (!list_empty(&dpm_prepared_list)) {
1193                 struct device *dev = to_device(dpm_prepared_list.prev);
1194
1195                 get_device(dev);
1196                 mutex_unlock(&dpm_list_mtx);
1197
1198                 error = device_suspend(dev);
1199
1200                 mutex_lock(&dpm_list_mtx);
1201                 if (error) {
1202                         pm_dev_err(dev, state, "", error);
1203                         dpm_save_failed_dev(dev_name(dev));
1204                         put_device(dev);
1205                         break;
1206                 }
1207                 if (!list_empty(&dev->power.entry))
1208                         list_move(&dev->power.entry, &dpm_suspended_list);
1209                 put_device(dev);
1210                 if (async_error)
1211                         break;
1212         }
1213         mutex_unlock(&dpm_list_mtx);
1214         async_synchronize_full();
1215         if (!error)
1216                 error = async_error;
1217         if (error) {
1218                 suspend_stats.failed_suspend++;
1219                 dpm_save_failed_step(SUSPEND_SUSPEND);
1220         } else
1221                 dpm_show_time(starttime, state, NULL);
1222         return error;
1223 }
1224
1225 /**
1226  * device_prepare - Prepare a device for system power transition.
1227  * @dev: Device to handle.
1228  * @state: PM transition of the system being carried out.
1229  *
1230  * Execute the ->prepare() callback(s) for given device.  No new children of the
1231  * device may be registered after this function has returned.
1232  */
1233 static int device_prepare(struct device *dev, pm_message_t state)
1234 {
1235         int (*callback)(struct device *) = NULL;
1236         char *info = NULL;
1237         int error = 0;
1238
1239         if (dev->power.syscore)
1240                 return 0;
1241
1242         /*
1243          * If a device's parent goes into runtime suspend at the wrong time,
1244          * it won't be possible to resume the device.  To prevent this we
1245          * block runtime suspend here, during the prepare phase, and allow
1246          * it again during the complete phase.
1247          */
1248         pm_runtime_get_noresume(dev);
1249
1250         device_lock(dev);
1251
1252         dev->power.wakeup_path = device_may_wakeup(dev);
1253
1254         if (dev->pm_domain) {
1255                 info = "preparing power domain ";
1256                 callback = dev->pm_domain->ops.prepare;
1257         } else if (dev->type && dev->type->pm) {
1258                 info = "preparing type ";
1259                 callback = dev->type->pm->prepare;
1260         } else if (dev->class && dev->class->pm) {
1261                 info = "preparing class ";
1262                 callback = dev->class->pm->prepare;
1263         } else if (dev->bus && dev->bus->pm) {
1264                 info = "preparing bus ";
1265                 callback = dev->bus->pm->prepare;
1266         }
1267
1268         if (!callback && dev->driver && dev->driver->pm) {
1269                 info = "preparing driver ";
1270                 callback = dev->driver->pm->prepare;
1271         }
1272
1273         if (callback) {
1274                 error = callback(dev);
1275                 suspend_report_result(callback, error);
1276         }
1277
1278         device_unlock(dev);
1279
1280         return error;
1281 }
1282
1283 /**
1284  * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1285  * @state: PM transition of the system being carried out.
1286  *
1287  * Execute the ->prepare() callback(s) for all devices.
1288  */
1289 int dpm_prepare(pm_message_t state)
1290 {
1291         int error = 0;
1292
1293         might_sleep();
1294
1295         mutex_lock(&dpm_list_mtx);
1296         while (!list_empty(&dpm_list)) {
1297                 struct device *dev = to_device(dpm_list.next);
1298
1299                 get_device(dev);
1300                 mutex_unlock(&dpm_list_mtx);
1301
1302                 error = device_prepare(dev, state);
1303
1304                 mutex_lock(&dpm_list_mtx);
1305                 if (error) {
1306                         if (error == -EAGAIN) {
1307                                 put_device(dev);
1308                                 error = 0;
1309                                 continue;
1310                         }
1311                         printk(KERN_INFO "PM: Device %s not prepared "
1312                                 "for power transition: code %d\n",
1313                                 dev_name(dev), error);
1314                         put_device(dev);
1315                         break;
1316                 }
1317                 dev->power.is_prepared = true;
1318                 if (!list_empty(&dev->power.entry))
1319                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
1320                 put_device(dev);
1321         }
1322         mutex_unlock(&dpm_list_mtx);
1323         return error;
1324 }
1325
1326 /**
1327  * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1328  * @state: PM transition of the system being carried out.
1329  *
1330  * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1331  * callbacks for them.
1332  */
1333 int dpm_suspend_start(pm_message_t state)
1334 {
1335         int error;
1336
1337         error = dpm_prepare(state);
1338         if (error) {
1339                 suspend_stats.failed_prepare++;
1340                 dpm_save_failed_step(SUSPEND_PREPARE);
1341         } else
1342                 error = dpm_suspend(state);
1343         return error;
1344 }
1345 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1346
1347 void __suspend_report_result(const char *function, void *fn, int ret)
1348 {
1349         if (ret)
1350                 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1351 }
1352 EXPORT_SYMBOL_GPL(__suspend_report_result);
1353
1354 /**
1355  * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1356  * @dev: Device to wait for.
1357  * @subordinate: Device that needs to wait for @dev.
1358  */
1359 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1360 {
1361         dpm_wait(dev, subordinate->power.async_suspend);
1362         return async_error;
1363 }
1364 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1365
1366 /**
1367  * dpm_for_each_dev - device iterator.
1368  * @data: data for the callback.
1369  * @fn: function to be called for each device.
1370  *
1371  * Iterate over devices in dpm_list, and call @fn for each device,
1372  * passing it @data.
1373  */
1374 void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
1375 {
1376         struct device *dev;
1377
1378         if (!fn)
1379                 return;
1380
1381         device_pm_lock();
1382         list_for_each_entry(dev, &dpm_list, power.entry)
1383                 fn(dev, data);
1384         device_pm_unlock();
1385 }
1386 EXPORT_SYMBOL_GPL(dpm_for_each_dev);