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