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