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