drivers/base/power/wakeup.c

   1 /*
   2  * drivers/base/power/wakeup.c - System wakeup events framework
   3  *
   4  * Copyright (c) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
   5  *
   6  * This file is released under the GPLv2.
   7  */
   8
   9 #include <linux/device.h>
  10 #include <linux/slab.h>
  11 #include <linux/sched.h>
  12 #include <linux/capability.h>
  13 #include <linux/export.h>
  14 #include <linux/suspend.h>
  15 #include <linux/seq_file.h>
  16 #include <linux/debugfs.h>
  17 #include <trace/events/power.h>
  18
  19 #include "power.h"
  20
  21 /*
  22  * If set, the suspend/hibernate code will abort transitions to a sleep state
  23  * if wakeup events are registered during or immediately before the transition.
  24  */
  25 bool events_check_enabled __read_mostly;
  26
  27 /* If set and the system is suspending, terminate the suspend. */
  28 static bool pm_abort_suspend __read_mostly;
  29
  30 /*
  31  * Combined counters of registered wakeup events and wakeup events in progress.
  32  * They need to be modified together atomically, so it's better to use one
  33  * atomic variable to hold them both.
  34  */
  35 static atomic_t combined_event_count = ATOMIC_INIT(0);
  36
  37 #define IN_PROGRESS_BITS        (sizeof(int) * 4)
  38 #define MAX_IN_PROGRESS         ((1 << IN_PROGRESS_BITS) - 1)
  39
  40 static void split_counters(unsigned int *cnt, unsigned int *inpr)
  41 {
  42         unsigned int comb = atomic_read(&combined_event_count);
  43
  44         *cnt = (comb >> IN_PROGRESS_BITS);
  45         *inpr = comb & MAX_IN_PROGRESS;
  46 }
  47
  48 /* A preserved old value of the events counter. */
  49 static unsigned int saved_count;
  50
  51 static DEFINE_SPINLOCK(events_lock);
  52
  53 static void pm_wakeup_timer_fn(unsigned long data);
  54
  55 static LIST_HEAD(wakeup_sources);
  56
  57 static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue);
  58
  59 static struct wakeup_source deleted_ws = {
  60         .name = "deleted",
  61         .lock =  __SPIN_LOCK_UNLOCKED(deleted_ws.lock),
  62 };
  63
  64 /**
  65  * wakeup_source_prepare - Prepare a new wakeup source for initialization.
  66  * @ws: Wakeup source to prepare.
  67  * @name: Pointer to the name of the new wakeup source.
  68  *
  69  * Callers must ensure that the @name string won't be freed when @ws is still in
  70  * use.
  71  */
  72 void wakeup_source_prepare(struct wakeup_source *ws, const char *name)
  73 {
  74         if (ws) {
  75                 memset(ws, 0, sizeof(*ws));
  76                 ws->name = name;
  77         }
  78 }
  79 EXPORT_SYMBOL_GPL(wakeup_source_prepare);
  80
  81 /**
  82  * wakeup_source_create - Create a struct wakeup_source object.
  83  * @name: Name of the new wakeup source.
  84  */
  85 struct wakeup_source *wakeup_source_create(const char *name)
  86 {
  87         struct wakeup_source *ws;
  88
  89         ws = kmalloc(sizeof(*ws), GFP_KERNEL);
  90         if (!ws)
  91                 return NULL;
  92
  93         wakeup_source_prepare(ws, name ? kstrdup(name, GFP_KERNEL) : NULL);
  94         return ws;
  95 }
  96 EXPORT_SYMBOL_GPL(wakeup_source_create);
  97
  98 /**
  99  * wakeup_source_drop - Prepare a struct wakeup_source object for destruction.
 100  * @ws: Wakeup source to prepare for destruction.
 101  *
 102  * Callers must ensure that __pm_stay_awake() or __pm_wakeup_event() will never
 103  * be run in parallel with this function for the same wakeup source object.
 104  */
 105 void wakeup_source_drop(struct wakeup_source *ws)
 106 {
 107         if (!ws)
 108                 return;
 109
 110         del_timer_sync(&ws->timer);
 111         __pm_relax(ws);
 112 }
 113 EXPORT_SYMBOL_GPL(wakeup_source_drop);
 114
 115 /*
 116  * Record wakeup_source statistics being deleted into a dummy wakeup_source.
 117  */
 118 static void wakeup_source_record(struct wakeup_source *ws)
 119 {
 120         unsigned long flags;
 121
 122         spin_lock_irqsave(&deleted_ws.lock, flags);
 123
 124         if (ws->event_count) {
 125                 deleted_ws.total_time =
 126                         ktime_add(deleted_ws.total_time, ws->total_time);
 127                 deleted_ws.prevent_sleep_time =
 128                         ktime_add(deleted_ws.prevent_sleep_time,
 129                                   ws->prevent_sleep_time);
 130                 deleted_ws.max_time =
 131                         ktime_compare(deleted_ws.max_time, ws->max_time) > 0 ?
 132                                 deleted_ws.max_time : ws->max_time;
 133                 deleted_ws.event_count += ws->event_count;
 134                 deleted_ws.active_count += ws->active_count;
 135                 deleted_ws.relax_count += ws->relax_count;
 136                 deleted_ws.expire_count += ws->expire_count;
 137                 deleted_ws.wakeup_count += ws->wakeup_count;
 138         }
 139
 140         spin_unlock_irqrestore(&deleted_ws.lock, flags);
 141 }
 142
 143 /**
 144  * wakeup_source_destroy - Destroy a struct wakeup_source object.
 145  * @ws: Wakeup source to destroy.
 146  *
 147  * Use only for wakeup source objects created with wakeup_source_create().
 148  */
 149 void wakeup_source_destroy(struct wakeup_source *ws)
 150 {
 151         if (!ws)
 152                 return;
 153
 154         wakeup_source_drop(ws);
 155         wakeup_source_record(ws);
 156         kfree(ws->name);
 157         kfree(ws);
 158 }
 159 EXPORT_SYMBOL_GPL(wakeup_source_destroy);
 160
 161 /**
 162  * wakeup_source_add - Add given object to the list of wakeup sources.
 163  * @ws: Wakeup source object to add to the list.
 164  */
 165 void wakeup_source_add(struct wakeup_source *ws)
 166 {
 167         unsigned long flags;
 168
 169         if (WARN_ON(!ws))
 170                 return;
 171
 172         spin_lock_init(&ws->lock);
 173         setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws);
 174         ws->active = false;
 175         ws->last_time = ktime_get();
 176
 177         spin_lock_irqsave(&events_lock, flags);
 178         list_add_rcu(&ws->entry, &wakeup_sources);
 179         spin_unlock_irqrestore(&events_lock, flags);
 180 }
 181 EXPORT_SYMBOL_GPL(wakeup_source_add);
 182
 183 /**
 184  * wakeup_source_remove - Remove given object from the wakeup sources list.
 185  * @ws: Wakeup source object to remove from the list.
 186  */
 187 void wakeup_source_remove(struct wakeup_source *ws)
 188 {
 189         unsigned long flags;
 190
 191         if (WARN_ON(!ws))
 192                 return;
 193
 194         spin_lock_irqsave(&events_lock, flags);
 195         list_del_rcu(&ws->entry);
 196         spin_unlock_irqrestore(&events_lock, flags);
 197         synchronize_rcu();
 198 }
 199 EXPORT_SYMBOL_GPL(wakeup_source_remove);
 200
 201 /**
 202  * wakeup_source_register - Create wakeup source and add it to the list.
 203  * @name: Name of the wakeup source to register.
 204  */
 205 struct wakeup_source *wakeup_source_register(const char *name)
 206 {
 207         struct wakeup_source *ws;
 208
 209         ws = wakeup_source_create(name);
 210         if (ws)
 211                 wakeup_source_add(ws);
 212
 213         return ws;
 214 }
 215 EXPORT_SYMBOL_GPL(wakeup_source_register);
 216
 217 /**
 218  * wakeup_source_unregister - Remove wakeup source from the list and remove it.
 219  * @ws: Wakeup source object to unregister.
 220  */
 221 void wakeup_source_unregister(struct wakeup_source *ws)
 222 {
 223         if (ws) {
 224                 wakeup_source_remove(ws);
 225                 wakeup_source_destroy(ws);
 226         }
 227 }
 228 EXPORT_SYMBOL_GPL(wakeup_source_unregister);
 229
 230 /**
 231  * device_wakeup_attach - Attach a wakeup source object to a device object.
 232  * @dev: Device to handle.
 233  * @ws: Wakeup source object to attach to @dev.
 234  *
 235  * This causes @dev to be treated as a wakeup device.
 236  */
 237 static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws)
 238 {
 239         spin_lock_irq(&dev->power.lock);
 240         if (dev->power.wakeup) {
 241                 spin_unlock_irq(&dev->power.lock);
 242                 return -EEXIST;
 243         }
 244         dev->power.wakeup = ws;
 245         spin_unlock_irq(&dev->power.lock);
 246         return 0;
 247 }
 248
 249 /**
 250  * device_wakeup_enable - Enable given device to be a wakeup source.
 251  * @dev: Device to handle.
 252  *
 253  * Create a wakeup source object, register it and attach it to @dev.
 254  */
 255 int device_wakeup_enable(struct device *dev)
 256 {
 257         struct wakeup_source *ws;
 258         int ret;
 259
 260         if (!dev || !dev->power.can_wakeup)
 261                 return -EINVAL;
 262
 263         ws = wakeup_source_register(dev_name(dev));
 264         if (!ws)
 265                 return -ENOMEM;
 266
 267         ret = device_wakeup_attach(dev, ws);
 268         if (ret)
 269                 wakeup_source_unregister(ws);
 270
 271         return ret;
 272 }
 273 EXPORT_SYMBOL_GPL(device_wakeup_enable);
 274
 275 /**
 276  * device_wakeup_detach - Detach a device's wakeup source object from it.
 277  * @dev: Device to detach the wakeup source object from.
 278  *
 279  * After it returns, @dev will not be treated as a wakeup device any more.
 280  */
 281 static struct wakeup_source *device_wakeup_detach(struct device *dev)
 282 {
 283         struct wakeup_source *ws;
 284
 285         spin_lock_irq(&dev->power.lock);
 286         ws = dev->power.wakeup;
 287         dev->power.wakeup = NULL;
 288         spin_unlock_irq(&dev->power.lock);
 289         return ws;
 290 }
 291
 292 /**
 293  * device_wakeup_disable - Do not regard a device as a wakeup source any more.
 294  * @dev: Device to handle.
 295  *
 296  * Detach the @dev's wakeup source object from it, unregister this wakeup source
 297  * object and destroy it.
 298  */
 299 int device_wakeup_disable(struct device *dev)
 300 {
 301         struct wakeup_source *ws;
 302
 303         if (!dev || !dev->power.can_wakeup)
 304                 return -EINVAL;
 305
 306         ws = device_wakeup_detach(dev);
 307         if (ws)
 308                 wakeup_source_unregister(ws);
 309
 310         return 0;
 311 }
 312 EXPORT_SYMBOL_GPL(device_wakeup_disable);
 313
 314 /**
 315  * device_set_wakeup_capable - Set/reset device wakeup capability flag.
 316  * @dev: Device to handle.
 317  * @capable: Whether or not @dev is capable of waking up the system from sleep.
 318  *
 319  * If @capable is set, set the @dev's power.can_wakeup flag and add its
 320  * wakeup-related attributes to sysfs.  Otherwise, unset the @dev's
 321  * power.can_wakeup flag and remove its wakeup-related attributes from sysfs.
 322  *
 323  * This function may sleep and it can't be called from any context where
 324  * sleeping is not allowed.
 325  */
 326 void device_set_wakeup_capable(struct device *dev, bool capable)
 327 {
 328         if (!!dev->power.can_wakeup == !!capable)
 329                 return;
 330
 331         if (device_is_registered(dev) && !list_empty(&dev->power.entry)) {
 332                 if (capable) {
 333                         if (wakeup_sysfs_add(dev))
 334                                 return;
 335                 } else {
 336                         wakeup_sysfs_remove(dev);
 337                 }
 338         }
 339         dev->power.can_wakeup = capable;
 340 }
 341 EXPORT_SYMBOL_GPL(device_set_wakeup_capable);
 342
 343 /**
 344  * device_init_wakeup - Device wakeup initialization.
 345  * @dev: Device to handle.
 346  * @enable: Whether or not to enable @dev as a wakeup device.
 347  *
 348  * By default, most devices should leave wakeup disabled.  The exceptions are
 349  * devices that everyone expects to be wakeup sources: keyboards, power buttons,
 350  * possibly network interfaces, etc.  Also, devices that don't generate their
 351  * own wakeup requests but merely forward requests from one bus to another
 352  * (like PCI bridges) should have wakeup enabled by default.
 353  */
 354 int device_init_wakeup(struct device *dev, bool enable)
 355 {
 356         int ret = 0;
 357
 358         if (!dev)
 359                 return -EINVAL;
 360
 361         if (enable) {
 362                 device_set_wakeup_capable(dev, true);
 363                 ret = device_wakeup_enable(dev);
 364         } else {
 365                 if (dev->power.can_wakeup)
 366                         device_wakeup_disable(dev);
 367
 368                 device_set_wakeup_capable(dev, false);
 369         }
 370
 371         return ret;
 372 }
 373 EXPORT_SYMBOL_GPL(device_init_wakeup);
 374
 375 /**
 376  * device_set_wakeup_enable - Enable or disable a device to wake up the system.
 377  * @dev: Device to handle.
 378  */
 379 int device_set_wakeup_enable(struct device *dev, bool enable)
 380 {
 381         if (!dev || !dev->power.can_wakeup)
 382                 return -EINVAL;
 383
 384         return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev);
 385 }
 386 EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
 387
 388 /**
 389  * wakeup_source_not_registered - validate the given wakeup source.
 390  * @ws: Wakeup source to be validated.
 391  */
 392 static bool wakeup_source_not_registered(struct wakeup_source *ws)
 393 {
 394         /*
 395          * Use timer struct to check if the given source is initialized
 396          * by wakeup_source_add.
 397          */
 398         return ws->timer.function != pm_wakeup_timer_fn ||
 399                    ws->timer.data != (unsigned long)ws;
 400 }
 401
 402 /*
 403  * The functions below use the observation that each wakeup event starts a
 404  * period in which the system should not be suspended.  The moment this period
 405  * will end depends on how the wakeup event is going to be processed after being
 406  * detected and all of the possible cases can be divided into two distinct
 407  * groups.
 408  *
 409  * First, a wakeup event may be detected by the same functional unit that will
 410  * carry out the entire processing of it and possibly will pass it to user space
 411  * for further processing.  In that case the functional unit that has detected
 412  * the event may later "close" the "no suspend" period associated with it
 413  * directly as soon as it has been dealt with.  The pair of pm_stay_awake() and
 414  * pm_relax(), balanced with each other, is supposed to be used in such
 415  * situations.
 416  *
 417  * Second, a wakeup event may be detected by one functional unit and processed
 418  * by another one.  In that case the unit that has detected it cannot really
 419  * "close" the "no suspend" period associated with it, unless it knows in
 420  * advance what's going to happen to the event during processing.  This
 421  * knowledge, however, may not be available to it, so it can simply specify time
 422  * to wait before the system can be suspended and pass it as the second
 423  * argument of pm_wakeup_event().
 424  *
 425  * It is valid to call pm_relax() after pm_wakeup_event(), in which case the
 426  * "no suspend" period will be ended either by the pm_relax(), or by the timer
 427  * function executed when the timer expires, whichever comes first.
 428  */
 429
 430 /**
 431  * wakup_source_activate - Mark given wakeup source as active.
 432  * @ws: Wakeup source to handle.
 433  *
 434  * Update the @ws' statistics and, if @ws has just been activated, notify the PM
 435  * core of the event by incrementing the counter of of wakeup events being
 436  * processed.
 437  */
 438 static void wakeup_source_activate(struct wakeup_source *ws)
 439 {
 440         unsigned int cec;
 441
 442         if (WARN_ONCE(wakeup_source_not_registered(ws),
 443                         "unregistered wakeup source\n"))
 444                 return;
 445
 446         /*
 447          * active wakeup source should bring the system
 448          * out of PM_SUSPEND_FREEZE state
 449          */
 450         freeze_wake();
 451
 452         ws->active = true;
 453         ws->active_count++;
 454         ws->last_time = ktime_get();
 455         if (ws->autosleep_enabled)
 456                 ws->start_prevent_time = ws->last_time;
 457
 458         /* Increment the counter of events in progress. */
 459         cec = atomic_inc_return(&combined_event_count);
 460
 461         trace_wakeup_source_activate(ws->name, cec);
 462 }
 463
 464 /**
 465  * wakeup_source_report_event - Report wakeup event using the given source.
 466  * @ws: Wakeup source to report the event for.
 467  */
 468 static void wakeup_source_report_event(struct wakeup_source *ws)
 469 {
 470         ws->event_count++;
 471         /* This is racy, but the counter is approximate anyway. */
 472         if (events_check_enabled)
 473                 ws->wakeup_count++;
 474
 475         if (!ws->active)
 476                 wakeup_source_activate(ws);
 477 }
 478
 479 /**
 480  * __pm_stay_awake - Notify the PM core of a wakeup event.
 481  * @ws: Wakeup source object associated with the source of the event.
 482  *
 483  * It is safe to call this function from interrupt context.
 484  */
 485 void __pm_stay_awake(struct wakeup_source *ws)
 486 {
 487         unsigned long flags;
 488
 489         if (!ws)
 490                 return;
 491
 492         spin_lock_irqsave(&ws->lock, flags);
 493
 494         wakeup_source_report_event(ws);
 495         del_timer(&ws->timer);
 496         ws->timer_expires = 0;
 497
 498         spin_unlock_irqrestore(&ws->lock, flags);
 499 }
 500 EXPORT_SYMBOL_GPL(__pm_stay_awake);
 501
 502 /**
 503  * pm_stay_awake - Notify the PM core that a wakeup event is being processed.
 504  * @dev: Device the wakeup event is related to.
 505  *
 506  * Notify the PM core of a wakeup event (signaled by @dev) by calling
 507  * __pm_stay_awake for the @dev's wakeup source object.
 508  *
 509  * Call this function after detecting of a wakeup event if pm_relax() is going
 510  * to be called directly after processing the event (and possibly passing it to
 511  * user space for further processing).
 512  */
 513 void pm_stay_awake(struct device *dev)
 514 {
 515         unsigned long flags;
 516
 517         if (!dev)
 518                 return;
 519
 520         spin_lock_irqsave(&dev->power.lock, flags);
 521         __pm_stay_awake(dev->power.wakeup);
 522         spin_unlock_irqrestore(&dev->power.lock, flags);
 523 }
 524 EXPORT_SYMBOL_GPL(pm_stay_awake);
 525
 526 #ifdef CONFIG_PM_AUTOSLEEP
 527 static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now)
 528 {
 529         ktime_t delta = ktime_sub(now, ws->start_prevent_time);
 530         ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta);
 531 }
 532 #else
 533 static inline void update_prevent_sleep_time(struct wakeup_source *ws,
 534                                              ktime_t now) {}
 535 #endif
 536
 537 /**
 538  * wakup_source_deactivate - Mark given wakeup source as inactive.
 539  * @ws: Wakeup source to handle.
 540  *
 541  * Update the @ws' statistics and notify the PM core that the wakeup source has
 542  * become inactive by decrementing the counter of wakeup events being processed
 543  * and incrementing the counter of registered wakeup events.
 544  */
 545 static void wakeup_source_deactivate(struct wakeup_source *ws)
 546 {
 547         unsigned int cnt, inpr, cec;
 548         ktime_t duration;
 549         ktime_t now;
 550
 551         ws->relax_count++;
 552         /*
 553          * __pm_relax() may be called directly or from a timer function.
 554          * If it is called directly right after the timer function has been
 555          * started, but before the timer function calls __pm_relax(), it is
 556          * possible that __pm_stay_awake() will be called in the meantime and
 557          * will set ws->active.  Then, ws->active may be cleared immediately
 558          * by the __pm_relax() called from the timer function, but in such a
 559          * case ws->relax_count will be different from ws->active_count.
 560          */
 561         if (ws->relax_count != ws->active_count) {
 562                 ws->relax_count--;
 563                 return;
 564         }
 565
 566         ws->active = false;
 567
 568         now = ktime_get();
 569         duration = ktime_sub(now, ws->last_time);
 570         ws->total_time = ktime_add(ws->total_time, duration);
 571         if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time))
 572                 ws->max_time = duration;
 573
 574         ws->last_time = now;
 575         del_timer(&ws->timer);
 576         ws->timer_expires = 0;
 577
 578         if (ws->autosleep_enabled)
 579                 update_prevent_sleep_time(ws, now);
 580
 581         /*
 582          * Increment the counter of registered wakeup events and decrement the
 583          * couter of wakeup events in progress simultaneously.
 584          */
 585         cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count);
 586         trace_wakeup_source_deactivate(ws->name, cec);
 587
 588         split_counters(&cnt, &inpr);
 589         if (!inpr && waitqueue_active(&wakeup_count_wait_queue))
 590                 wake_up(&wakeup_count_wait_queue);
 591 }
 592
 593 /**
 594  * __pm_relax - Notify the PM core that processing of a wakeup event has ended.
 595  * @ws: Wakeup source object associated with the source of the event.
 596  *
 597  * Call this function for wakeup events whose processing started with calling
 598  * __pm_stay_awake().
 599  *
 600  * It is safe to call it from interrupt context.
 601  */
 602 void __pm_relax(struct wakeup_source *ws)
 603 {
 604         unsigned long flags;
 605
 606         if (!ws)
 607                 return;
 608
 609         spin_lock_irqsave(&ws->lock, flags);
 610         if (ws->active)
 611                 wakeup_source_deactivate(ws);
 612         spin_unlock_irqrestore(&ws->lock, flags);
 613 }
 614 EXPORT_SYMBOL_GPL(__pm_relax);
 615
 616 /**
 617  * pm_relax - Notify the PM core that processing of a wakeup event has ended.
 618  * @dev: Device that signaled the event.
 619  *
 620  * Execute __pm_relax() for the @dev's wakeup source object.
 621  */
 622 void pm_relax(struct device *dev)
 623 {
 624         unsigned long flags;
 625
 626         if (!dev)
 627                 return;
 628
 629         spin_lock_irqsave(&dev->power.lock, flags);
 630         __pm_relax(dev->power.wakeup);
 631         spin_unlock_irqrestore(&dev->power.lock, flags);
 632 }
 633 EXPORT_SYMBOL_GPL(pm_relax);
 634
 635 /**
 636  * pm_wakeup_timer_fn - Delayed finalization of a wakeup event.
 637  * @data: Address of the wakeup source object associated with the event source.
 638  *
 639  * Call wakeup_source_deactivate() for the wakeup source whose address is stored
 640  * in @data if it is currently active and its timer has not been canceled and
 641  * the expiration time of the timer is not in future.
 642  */
 643 static void pm_wakeup_timer_fn(unsigned long data)
 644 {
 645         struct wakeup_source *ws = (struct wakeup_source *)data;
 646         unsigned long flags;
 647
 648         spin_lock_irqsave(&ws->lock, flags);
 649
 650         if (ws->active && ws->timer_expires
 651             && time_after_eq(jiffies, ws->timer_expires)) {
 652                 wakeup_source_deactivate(ws);
 653                 ws->expire_count++;
 654         }
 655
 656         spin_unlock_irqrestore(&ws->lock, flags);
 657 }
 658
 659 /**
 660  * __pm_wakeup_event - Notify the PM core of a wakeup event.
 661  * @ws: Wakeup source object associated with the event source.
 662  * @msec: Anticipated event processing time (in milliseconds).
 663  *
 664  * Notify the PM core of a wakeup event whose source is @ws that will take
 665  * approximately @msec milliseconds to be processed by the kernel.  If @ws is
 666  * not active, activate it.  If @msec is nonzero, set up the @ws' timer to
 667  * execute pm_wakeup_timer_fn() in future.
 668  *
 669  * It is safe to call this function from interrupt context.
 670  */
 671 void __pm_wakeup_event(struct wakeup_source *ws, unsigned int msec)
 672 {
 673         unsigned long flags;
 674         unsigned long expires;
 675
 676         if (!ws)
 677                 return;
 678
 679         spin_lock_irqsave(&ws->lock, flags);
 680
 681         wakeup_source_report_event(ws);
 682
 683         if (!msec) {
 684                 wakeup_source_deactivate(ws);
 685                 goto unlock;
 686         }
 687
 688         expires = jiffies + msecs_to_jiffies(msec);
 689         if (!expires)
 690                 expires = 1;
 691
 692         if (!ws->timer_expires || time_after(expires, ws->timer_expires)) {
 693                 mod_timer(&ws->timer, expires);
 694                 ws->timer_expires = expires;
 695         }
 696
 697  unlock:
 698         spin_unlock_irqrestore(&ws->lock, flags);
 699 }
 700 EXPORT_SYMBOL_GPL(__pm_wakeup_event);
 701
 702
 703 /**
 704  * pm_wakeup_event - Notify the PM core of a wakeup event.
 705  * @dev: Device the wakeup event is related to.
 706  * @msec: Anticipated event processing time (in milliseconds).
 707  *
 708  * Call __pm_wakeup_event() for the @dev's wakeup source object.
 709  */
 710 void pm_wakeup_event(struct device *dev, unsigned int msec)
 711 {
 712         unsigned long flags;
 713
 714         if (!dev)
 715                 return;
 716
 717         spin_lock_irqsave(&dev->power.lock, flags);
 718         __pm_wakeup_event(dev->power.wakeup, msec);
 719         spin_unlock_irqrestore(&dev->power.lock, flags);
 720 }
 721 EXPORT_SYMBOL_GPL(pm_wakeup_event);
 722
 723 void pm_print_active_wakeup_sources(void)
 724 {
 725         struct wakeup_source *ws;
 726         int active = 0;
 727         struct wakeup_source *last_activity_ws = NULL;
 728
 729         rcu_read_lock();
 730         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 731                 if (ws->active) {
 732                         pr_info("active wakeup source: %s\n", ws->name);
 733                         active = 1;
 734                 } else if (!active &&
 735                            (!last_activity_ws ||
 736                             ktime_to_ns(ws->last_time) >
 737                             ktime_to_ns(last_activity_ws->last_time))) {
 738                         last_activity_ws = ws;
 739                 }
 740         }
 741
 742         if (!active && last_activity_ws)
 743                 pr_info("last active wakeup source: %s\n",
 744                         last_activity_ws->name);
 745         rcu_read_unlock();
 746 }
 747 EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources);
 748
 749 /**
 750  * pm_wakeup_pending - Check if power transition in progress should be aborted.
 751  *
 752  * Compare the current number of registered wakeup events with its preserved
 753  * value from the past and return true if new wakeup events have been registered
 754  * since the old value was stored.  Also return true if the current number of
 755  * wakeup events being processed is different from zero.
 756  */
 757 bool pm_wakeup_pending(void)
 758 {
 759         unsigned long flags;
 760         bool ret = false;
 761
 762         spin_lock_irqsave(&events_lock, flags);
 763         if (events_check_enabled) {
 764                 unsigned int cnt, inpr;
 765
 766                 split_counters(&cnt, &inpr);
 767                 ret = (cnt != saved_count || inpr > 0);
 768                 events_check_enabled = !ret;
 769         }
 770         spin_unlock_irqrestore(&events_lock, flags);
 771
 772         if (ret) {
 773                 pr_info("PM: Wakeup pending, aborting suspend\n");
 774                 pm_print_active_wakeup_sources();
 775         }
 776
 777         return ret || pm_abort_suspend;
 778 }
 779
 780 void pm_system_wakeup(void)
 781 {
 782         pm_abort_suspend = true;
 783         freeze_wake();
 784 }
 785 EXPORT_SYMBOL_GPL(pm_system_wakeup);
 786
 787 void pm_wakeup_clear(void)
 788 {
 789         pm_abort_suspend = false;
 790 }
 791
 792 /**
 793  * pm_get_wakeup_count - Read the number of registered wakeup events.
 794  * @count: Address to store the value at.
 795  * @block: Whether or not to block.
 796  *
 797  * Store the number of registered wakeup events at the address in @count.  If
 798  * @block is set, block until the current number of wakeup events being
 799  * processed is zero.
 800  *
 801  * Return 'false' if the current number of wakeup events being processed is
 802  * nonzero.  Otherwise return 'true'.
 803  */
 804 bool pm_get_wakeup_count(unsigned int *count, bool block)
 805 {
 806         unsigned int cnt, inpr;
 807
 808         if (block) {
 809                 DEFINE_WAIT(wait);
 810
 811                 for (;;) {
 812                         prepare_to_wait(&wakeup_count_wait_queue, &wait,
 813                                         TASK_INTERRUPTIBLE);
 814                         split_counters(&cnt, &inpr);
 815                         if (inpr == 0 || signal_pending(current))
 816                                 break;
 817
 818                         schedule();
 819                 }
 820                 finish_wait(&wakeup_count_wait_queue, &wait);
 821         }
 822
 823         split_counters(&cnt, &inpr);
 824         *count = cnt;
 825         return !inpr;
 826 }
 827
 828 /**
 829  * pm_save_wakeup_count - Save the current number of registered wakeup events.
 830  * @count: Value to compare with the current number of registered wakeup events.
 831  *
 832  * If @count is equal to the current number of registered wakeup events and the
 833  * current number of wakeup events being processed is zero, store @count as the
 834  * old number of registered wakeup events for pm_check_wakeup_events(), enable
 835  * wakeup events detection and return 'true'.  Otherwise disable wakeup events
 836  * detection and return 'false'.
 837  */
 838 bool pm_save_wakeup_count(unsigned int count)
 839 {
 840         unsigned int cnt, inpr;
 841         unsigned long flags;
 842
 843         events_check_enabled = false;
 844         spin_lock_irqsave(&events_lock, flags);
 845         split_counters(&cnt, &inpr);
 846         if (cnt == count && inpr == 0) {
 847                 saved_count = count;
 848                 events_check_enabled = true;
 849         }
 850         spin_unlock_irqrestore(&events_lock, flags);
 851         return events_check_enabled;
 852 }
 853
 854 #ifdef CONFIG_PM_AUTOSLEEP
 855 /**
 856  * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources.
 857  * @enabled: Whether to set or to clear the autosleep_enabled flags.
 858  */
 859 void pm_wakep_autosleep_enabled(bool set)
 860 {
 861         struct wakeup_source *ws;
 862         ktime_t now = ktime_get();
 863
 864         rcu_read_lock();
 865         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 866                 spin_lock_irq(&ws->lock);
 867                 if (ws->autosleep_enabled != set) {
 868                         ws->autosleep_enabled = set;
 869                         if (ws->active) {
 870                                 if (set)
 871                                         ws->start_prevent_time = now;
 872                                 else
 873                                         update_prevent_sleep_time(ws, now);
 874                         }
 875                 }
 876                 spin_unlock_irq(&ws->lock);
 877         }
 878         rcu_read_unlock();
 879 }
 880 #endif /* CONFIG_PM_AUTOSLEEP */
 881
 882 static struct dentry *wakeup_sources_stats_dentry;
 883
 884 /**
 885  * print_wakeup_source_stats - Print wakeup source statistics information.
 886  * @m: seq_file to print the statistics into.
 887  * @ws: Wakeup source object to print the statistics for.
 888  */
 889 static int print_wakeup_source_stats(struct seq_file *m,
 890                                      struct wakeup_source *ws)
 891 {
 892         unsigned long flags;
 893         ktime_t total_time;
 894         ktime_t max_time;
 895         unsigned long active_count;
 896         ktime_t active_time;
 897         ktime_t prevent_sleep_time;
 898
 899         spin_lock_irqsave(&ws->lock, flags);
 900
 901         total_time = ws->total_time;
 902         max_time = ws->max_time;
 903         prevent_sleep_time = ws->prevent_sleep_time;
 904         active_count = ws->active_count;
 905         if (ws->active) {
 906                 ktime_t now = ktime_get();
 907
 908                 active_time = ktime_sub(now, ws->last_time);
 909                 total_time = ktime_add(total_time, active_time);
 910                 if (active_time.tv64 > max_time.tv64)
 911                         max_time = active_time;
 912
 913                 if (ws->autosleep_enabled)
 914                         prevent_sleep_time = ktime_add(prevent_sleep_time,
 915                                 ktime_sub(now, ws->start_prevent_time));
 916         } else {
 917                 active_time = ktime_set(0, 0);
 918         }
 919
 920         seq_printf(m, "%-12s\t%lu\t\t%lu\t\t%lu\t\t%lu\t\t%lld\t\t%lld\t\t%lld\t\t%lld\t\t%lld\n",
 921                    ws->name, active_count, ws->event_count,
 922                    ws->wakeup_count, ws->expire_count,
 923                    ktime_to_ms(active_time), ktime_to_ms(total_time),
 924                    ktime_to_ms(max_time), ktime_to_ms(ws->last_time),
 925                    ktime_to_ms(prevent_sleep_time));
 926
 927         spin_unlock_irqrestore(&ws->lock, flags);
 928
 929         return 0;
 930 }
 931
 932 /**
 933  * wakeup_sources_stats_show - Print wakeup sources statistics information.
 934  * @m: seq_file to print the statistics into.
 935  */
 936 static int wakeup_sources_stats_show(struct seq_file *m, void *unused)
 937 {
 938         struct wakeup_source *ws;
 939
 940         seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t"
 941                 "expire_count\tactive_since\ttotal_time\tmax_time\t"
 942                 "last_change\tprevent_suspend_time\n");
 943
 944         rcu_read_lock();
 945         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
 946                 print_wakeup_source_stats(m, ws);
 947         rcu_read_unlock();
 948
 949         print_wakeup_source_stats(m, &deleted_ws);
 950
 951         return 0;
 952 }
 953
 954 static int wakeup_sources_stats_open(struct inode *inode, struct file *file)
 955 {
 956         return single_open(file, wakeup_sources_stats_show, NULL);
 957 }
 958
 959 static const struct file_operations wakeup_sources_stats_fops = {
 960         .owner = THIS_MODULE,
 961         .open = wakeup_sources_stats_open,
 962         .read = seq_read,
 963         .llseek = seq_lseek,
 964         .release = single_release,
 965 };
 966
 967 static int __init wakeup_sources_debugfs_init(void)
 968 {
 969         wakeup_sources_stats_dentry = debugfs_create_file("wakeup_sources",
 970                         S_IRUGO, NULL, NULL, &wakeup_sources_stats_fops);
 971         return 0;
 972 }
 973
 974 postcore_initcall(wakeup_sources_debugfs_init);