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