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 <linux/pm_wakeirq.h>
  18 #include <trace/events/power.h>
  19
  20 #include "power.h"
  21
  22 /*
  23  * If set, the suspend/hibernate code will abort transitions to a sleep state
  24  * if wakeup events are registered during or immediately before the transition.
  25  */
  26 bool events_check_enabled __read_mostly;
  27
  28 /* First wakeup IRQ seen by the kernel in the last cycle. */
  29 unsigned int pm_wakeup_irq __read_mostly;
  30
  31 /* If set and the system is suspending, terminate the suspend. */
  32 static bool pm_abort_suspend __read_mostly;
  33
  34 /*
  35  * Combined counters of registered wakeup events and wakeup events in progress.
  36  * They need to be modified together atomically, so it's better to use one
  37  * atomic variable to hold them both.
  38  */
  39 static atomic_t combined_event_count = ATOMIC_INIT(0);
  40
  41 #define IN_PROGRESS_BITS        (sizeof(int) * 4)
  42 #define MAX_IN_PROGRESS         ((1 << IN_PROGRESS_BITS) - 1)
  43
  44 static void split_counters(unsigned int *cnt, unsigned int *inpr)
  45 {
  46         unsigned int comb = atomic_read(&combined_event_count);
  47
  48         *cnt = (comb >> IN_PROGRESS_BITS);
  49         *inpr = comb & MAX_IN_PROGRESS;
  50 }
  51
  52 /* A preserved old value of the events counter. */
  53 static unsigned int saved_count;
  54
  55 static DEFINE_SPINLOCK(events_lock);
  56
  57 static void pm_wakeup_timer_fn(unsigned long data);
  58
  59 static LIST_HEAD(wakeup_sources);
  60
  61 static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue);
  62
  63 DEFINE_STATIC_SRCU(wakeup_srcu);
  64
  65 static struct wakeup_source deleted_ws = {
  66         .name = "deleted",
  67         .lock =  __SPIN_LOCK_UNLOCKED(deleted_ws.lock),
  68 };
  69
  70 /**
  71  * wakeup_source_prepare - Prepare a new wakeup source for initialization.
  72  * @ws: Wakeup source to prepare.
  73  * @name: Pointer to the name of the new wakeup source.
  74  *
  75  * Callers must ensure that the @name string won't be freed when @ws is still in
  76  * use.
  77  */
  78 void wakeup_source_prepare(struct wakeup_source *ws, const char *name)
  79 {
  80         if (ws) {
  81                 memset(ws, 0, sizeof(*ws));
  82                 ws->name = name;
  83         }
  84 }
  85 EXPORT_SYMBOL_GPL(wakeup_source_prepare);
  86
  87 /**
  88  * wakeup_source_create - Create a struct wakeup_source object.
  89  * @name: Name of the new wakeup source.
  90  */
  91 struct wakeup_source *wakeup_source_create(const char *name)
  92 {
  93         struct wakeup_source *ws;
  94
  95         ws = kmalloc(sizeof(*ws), GFP_KERNEL);
  96         if (!ws)
  97                 return NULL;
  98
  99         wakeup_source_prepare(ws, name ? kstrdup_const(name, GFP_KERNEL) : NULL);
 100         return ws;
 101 }
 102 EXPORT_SYMBOL_GPL(wakeup_source_create);
 103
 104 /**
 105  * wakeup_source_drop - Prepare a struct wakeup_source object for destruction.
 106  * @ws: Wakeup source to prepare for destruction.
 107  *
 108  * Callers must ensure that __pm_stay_awake() or __pm_wakeup_event() will never
 109  * be run in parallel with this function for the same wakeup source object.
 110  */
 111 void wakeup_source_drop(struct wakeup_source *ws)
 112 {
 113         if (!ws)
 114                 return;
 115
 116         __pm_relax(ws);
 117 }
 118 EXPORT_SYMBOL_GPL(wakeup_source_drop);
 119
 120 /*
 121  * Record wakeup_source statistics being deleted into a dummy wakeup_source.
 122  */
 123 static void wakeup_source_record(struct wakeup_source *ws)
 124 {
 125         unsigned long flags;
 126
 127         spin_lock_irqsave(&deleted_ws.lock, flags);
 128
 129         if (ws->event_count) {
 130                 deleted_ws.total_time =
 131                         ktime_add(deleted_ws.total_time, ws->total_time);
 132                 deleted_ws.prevent_sleep_time =
 133                         ktime_add(deleted_ws.prevent_sleep_time,
 134                                   ws->prevent_sleep_time);
 135                 deleted_ws.max_time =
 136                         ktime_compare(deleted_ws.max_time, ws->max_time) > 0 ?
 137                                 deleted_ws.max_time : ws->max_time;
 138                 deleted_ws.event_count += ws->event_count;
 139                 deleted_ws.active_count += ws->active_count;
 140                 deleted_ws.relax_count += ws->relax_count;
 141                 deleted_ws.expire_count += ws->expire_count;
 142                 deleted_ws.wakeup_count += ws->wakeup_count;
 143         }
 144
 145         spin_unlock_irqrestore(&deleted_ws.lock, flags);
 146 }
 147
 148 /**
 149  * wakeup_source_destroy - Destroy a struct wakeup_source object.
 150  * @ws: Wakeup source to destroy.
 151  *
 152  * Use only for wakeup source objects created with wakeup_source_create().
 153  */
 154 void wakeup_source_destroy(struct wakeup_source *ws)
 155 {
 156         if (!ws)
 157                 return;
 158
 159         wakeup_source_drop(ws);
 160         wakeup_source_record(ws);
 161         kfree_const(ws->name);
 162         kfree(ws);
 163 }
 164 EXPORT_SYMBOL_GPL(wakeup_source_destroy);
 165
 166 /**
 167  * wakeup_source_add - Add given object to the list of wakeup sources.
 168  * @ws: Wakeup source object to add to the list.
 169  */
 170 void wakeup_source_add(struct wakeup_source *ws)
 171 {
 172         unsigned long flags;
 173
 174         if (WARN_ON(!ws))
 175                 return;
 176
 177         spin_lock_init(&ws->lock);
 178         setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws);
 179         ws->active = false;
 180         ws->last_time = ktime_get();
 181
 182         spin_lock_irqsave(&events_lock, flags);
 183         list_add_rcu(&ws->entry, &wakeup_sources);
 184         spin_unlock_irqrestore(&events_lock, flags);
 185 }
 186 EXPORT_SYMBOL_GPL(wakeup_source_add);
 187
 188 /**
 189  * wakeup_source_remove - Remove given object from the wakeup sources list.
 190  * @ws: Wakeup source object to remove from the list.
 191  */
 192 void wakeup_source_remove(struct wakeup_source *ws)
 193 {
 194         unsigned long flags;
 195
 196         if (WARN_ON(!ws))
 197                 return;
 198
 199         spin_lock_irqsave(&events_lock, flags);
 200         list_del_rcu(&ws->entry);
 201         spin_unlock_irqrestore(&events_lock, flags);
 202         synchronize_srcu(&wakeup_srcu);
 203
 204         del_timer_sync(&ws->timer);
 205         /*
 206          * Clear timer.function to make wakeup_source_not_registered() treat
 207          * this wakeup source as not registered.
 208          */
 209         ws->timer.function = NULL;
 210 }
 211 EXPORT_SYMBOL_GPL(wakeup_source_remove);
 212
 213 /**
 214  * wakeup_source_register - Create wakeup source and add it to the list.
 215  * @name: Name of the wakeup source to register.
 216  */
 217 struct wakeup_source *wakeup_source_register(const char *name)
 218 {
 219         struct wakeup_source *ws;
 220
 221         ws = wakeup_source_create(name);
 222         if (ws)
 223                 wakeup_source_add(ws);
 224
 225         return ws;
 226 }
 227 EXPORT_SYMBOL_GPL(wakeup_source_register);
 228
 229 /**
 230  * wakeup_source_unregister - Remove wakeup source from the list and remove it.
 231  * @ws: Wakeup source object to unregister.
 232  */
 233 void wakeup_source_unregister(struct wakeup_source *ws)
 234 {
 235         if (ws) {
 236                 wakeup_source_remove(ws);
 237                 wakeup_source_destroy(ws);
 238         }
 239 }
 240 EXPORT_SYMBOL_GPL(wakeup_source_unregister);
 241
 242 /**
 243  * device_wakeup_attach - Attach a wakeup source object to a device object.
 244  * @dev: Device to handle.
 245  * @ws: Wakeup source object to attach to @dev.
 246  *
 247  * This causes @dev to be treated as a wakeup device.
 248  */
 249 static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws)
 250 {
 251         spin_lock_irq(&dev->power.lock);
 252         if (dev->power.wakeup) {
 253                 spin_unlock_irq(&dev->power.lock);
 254                 return -EEXIST;
 255         }
 256         dev->power.wakeup = ws;
 257         if (dev->power.wakeirq)
 258                 device_wakeup_attach_irq(dev, dev->power.wakeirq);
 259         spin_unlock_irq(&dev->power.lock);
 260         return 0;
 261 }
 262
 263 /**
 264  * device_wakeup_enable - Enable given device to be a wakeup source.
 265  * @dev: Device to handle.
 266  *
 267  * Create a wakeup source object, register it and attach it to @dev.
 268  */
 269 int device_wakeup_enable(struct device *dev)
 270 {
 271         struct wakeup_source *ws;
 272         int ret;
 273
 274         if (!dev || !dev->power.can_wakeup)
 275                 return -EINVAL;
 276
 277         ws = wakeup_source_register(dev_name(dev));
 278         if (!ws)
 279                 return -ENOMEM;
 280
 281         ret = device_wakeup_attach(dev, ws);
 282         if (ret)
 283                 wakeup_source_unregister(ws);
 284
 285         return ret;
 286 }
 287 EXPORT_SYMBOL_GPL(device_wakeup_enable);
 288
 289 /**
 290  * device_wakeup_attach_irq - Attach a wakeirq to a wakeup source
 291  * @dev: Device to handle
 292  * @wakeirq: Device specific wakeirq entry
 293  *
 294  * Attach a device wakeirq to the wakeup source so the device
 295  * wake IRQ can be configured automatically for suspend and
 296  * resume.
 297  *
 298  * Call under the device's power.lock lock.
 299  */
 300 int device_wakeup_attach_irq(struct device *dev,
 301                              struct wake_irq *wakeirq)
 302 {
 303         struct wakeup_source *ws;
 304
 305         ws = dev->power.wakeup;
 306         if (!ws) {
 307                 dev_err(dev, "forgot to call call device_init_wakeup?\n");
 308                 return -EINVAL;
 309         }
 310
 311         if (ws->wakeirq)
 312                 return -EEXIST;
 313
 314         ws->wakeirq = wakeirq;
 315         return 0;
 316 }
 317
 318 /**
 319  * device_wakeup_detach_irq - Detach a wakeirq from a wakeup source
 320  * @dev: Device to handle
 321  *
 322  * Removes a device wakeirq from the wakeup source.
 323  *
 324  * Call under the device's power.lock lock.
 325  */
 326 void device_wakeup_detach_irq(struct device *dev)
 327 {
 328         struct wakeup_source *ws;
 329
 330         ws = dev->power.wakeup;
 331         if (ws)
 332                 ws->wakeirq = NULL;
 333 }
 334
 335 /**
 336  * device_wakeup_arm_wake_irqs(void)
 337  *
 338  * Itereates over the list of device wakeirqs to arm them.
 339  */
 340 void device_wakeup_arm_wake_irqs(void)
 341 {
 342         struct wakeup_source *ws;
 343         int srcuidx;
 344
 345         srcuidx = srcu_read_lock(&wakeup_srcu);
 346         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
 347                 dev_pm_arm_wake_irq(ws->wakeirq);
 348         srcu_read_unlock(&wakeup_srcu, srcuidx);
 349 }
 350
 351 /**
 352  * device_wakeup_disarm_wake_irqs(void)
 353  *
 354  * Itereates over the list of device wakeirqs to disarm them.
 355  */
 356 void device_wakeup_disarm_wake_irqs(void)
 357 {
 358         struct wakeup_source *ws;
 359         int srcuidx;
 360
 361         srcuidx = srcu_read_lock(&wakeup_srcu);
 362         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
 363                 dev_pm_disarm_wake_irq(ws->wakeirq);
 364         srcu_read_unlock(&wakeup_srcu, srcuidx);
 365 }
 366
 367 /**
 368  * device_wakeup_detach - Detach a device's wakeup source object from it.
 369  * @dev: Device to detach the wakeup source object from.
 370  *
 371  * After it returns, @dev will not be treated as a wakeup device any more.
 372  */
 373 static struct wakeup_source *device_wakeup_detach(struct device *dev)
 374 {
 375         struct wakeup_source *ws;
 376
 377         spin_lock_irq(&dev->power.lock);
 378         ws = dev->power.wakeup;
 379         dev->power.wakeup = NULL;
 380         spin_unlock_irq(&dev->power.lock);
 381         return ws;
 382 }
 383
 384 /**
 385  * device_wakeup_disable - Do not regard a device as a wakeup source any more.
 386  * @dev: Device to handle.
 387  *
 388  * Detach the @dev's wakeup source object from it, unregister this wakeup source
 389  * object and destroy it.
 390  */
 391 int device_wakeup_disable(struct device *dev)
 392 {
 393         struct wakeup_source *ws;
 394
 395         if (!dev || !dev->power.can_wakeup)
 396                 return -EINVAL;
 397
 398         ws = device_wakeup_detach(dev);
 399         wakeup_source_unregister(ws);
 400         return 0;
 401 }
 402 EXPORT_SYMBOL_GPL(device_wakeup_disable);
 403
 404 /**
 405  * device_set_wakeup_capable - Set/reset device wakeup capability flag.
 406  * @dev: Device to handle.
 407  * @capable: Whether or not @dev is capable of waking up the system from sleep.
 408  *
 409  * If @capable is set, set the @dev's power.can_wakeup flag and add its
 410  * wakeup-related attributes to sysfs.  Otherwise, unset the @dev's
 411  * power.can_wakeup flag and remove its wakeup-related attributes from sysfs.
 412  *
 413  * This function may sleep and it can't be called from any context where
 414  * sleeping is not allowed.
 415  */
 416 void device_set_wakeup_capable(struct device *dev, bool capable)
 417 {
 418         if (!!dev->power.can_wakeup == !!capable)
 419                 return;
 420
 421         if (device_is_registered(dev) && !list_empty(&dev->power.entry)) {
 422                 if (capable) {
 423                         if (wakeup_sysfs_add(dev))
 424                                 return;
 425                 } else {
 426                         wakeup_sysfs_remove(dev);
 427                 }
 428         }
 429         dev->power.can_wakeup = capable;
 430 }
 431 EXPORT_SYMBOL_GPL(device_set_wakeup_capable);
 432
 433 /**
 434  * device_init_wakeup - Device wakeup initialization.
 435  * @dev: Device to handle.
 436  * @enable: Whether or not to enable @dev as a wakeup device.
 437  *
 438  * By default, most devices should leave wakeup disabled.  The exceptions are
 439  * devices that everyone expects to be wakeup sources: keyboards, power buttons,
 440  * possibly network interfaces, etc.  Also, devices that don't generate their
 441  * own wakeup requests but merely forward requests from one bus to another
 442  * (like PCI bridges) should have wakeup enabled by default.
 443  */
 444 int device_init_wakeup(struct device *dev, bool enable)
 445 {
 446         int ret = 0;
 447
 448         if (!dev)
 449                 return -EINVAL;
 450
 451         if (enable) {
 452                 device_set_wakeup_capable(dev, true);
 453                 ret = device_wakeup_enable(dev);
 454         } else {
 455                 if (dev->power.can_wakeup)
 456                         device_wakeup_disable(dev);
 457
 458                 device_set_wakeup_capable(dev, false);
 459         }
 460
 461         return ret;
 462 }
 463 EXPORT_SYMBOL_GPL(device_init_wakeup);
 464
 465 /**
 466  * device_set_wakeup_enable - Enable or disable a device to wake up the system.
 467  * @dev: Device to handle.
 468  */
 469 int device_set_wakeup_enable(struct device *dev, bool enable)
 470 {
 471         if (!dev || !dev->power.can_wakeup)
 472                 return -EINVAL;
 473
 474         return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev);
 475 }
 476 EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
 477
 478 /**
 479  * wakeup_source_not_registered - validate the given wakeup source.
 480  * @ws: Wakeup source to be validated.
 481  */
 482 static bool wakeup_source_not_registered(struct wakeup_source *ws)
 483 {
 484         /*
 485          * Use timer struct to check if the given source is initialized
 486          * by wakeup_source_add.
 487          */
 488         return ws->timer.function != pm_wakeup_timer_fn ||
 489                    ws->timer.data != (unsigned long)ws;
 490 }
 491
 492 /*
 493  * The functions below use the observation that each wakeup event starts a
 494  * period in which the system should not be suspended.  The moment this period
 495  * will end depends on how the wakeup event is going to be processed after being
 496  * detected and all of the possible cases can be divided into two distinct
 497  * groups.
 498  *
 499  * First, a wakeup event may be detected by the same functional unit that will
 500  * carry out the entire processing of it and possibly will pass it to user space
 501  * for further processing.  In that case the functional unit that has detected
 502  * the event may later "close" the "no suspend" period associated with it
 503  * directly as soon as it has been dealt with.  The pair of pm_stay_awake() and
 504  * pm_relax(), balanced with each other, is supposed to be used in such
 505  * situations.
 506  *
 507  * Second, a wakeup event may be detected by one functional unit and processed
 508  * by another one.  In that case the unit that has detected it cannot really
 509  * "close" the "no suspend" period associated with it, unless it knows in
 510  * advance what's going to happen to the event during processing.  This
 511  * knowledge, however, may not be available to it, so it can simply specify time
 512  * to wait before the system can be suspended and pass it as the second
 513  * argument of pm_wakeup_event().
 514  *
 515  * It is valid to call pm_relax() after pm_wakeup_event(), in which case the
 516  * "no suspend" period will be ended either by the pm_relax(), or by the timer
 517  * function executed when the timer expires, whichever comes first.
 518  */
 519
 520 /**
 521  * wakup_source_activate - Mark given wakeup source as active.
 522  * @ws: Wakeup source to handle.
 523  *
 524  * Update the @ws' statistics and, if @ws has just been activated, notify the PM
 525  * core of the event by incrementing the counter of of wakeup events being
 526  * processed.
 527  */
 528 static void wakeup_source_activate(struct wakeup_source *ws)
 529 {
 530         unsigned int cec;
 531
 532         if (WARN_ONCE(wakeup_source_not_registered(ws),
 533                         "unregistered wakeup source\n"))
 534                 return;
 535
 536         /*
 537          * active wakeup source should bring the system
 538          * out of PM_SUSPEND_FREEZE state
 539          */
 540         freeze_wake();
 541
 542         ws->active = true;
 543         ws->active_count++;
 544         ws->last_time = ktime_get();
 545         if (ws->autosleep_enabled)
 546                 ws->start_prevent_time = ws->last_time;
 547
 548         /* Increment the counter of events in progress. */
 549         cec = atomic_inc_return(&combined_event_count);
 550
 551         trace_wakeup_source_activate(ws->name, cec);
 552 }
 553
 554 /**
 555  * wakeup_source_report_event - Report wakeup event using the given source.
 556  * @ws: Wakeup source to report the event for.
 557  */
 558 static void wakeup_source_report_event(struct wakeup_source *ws)
 559 {
 560         ws->event_count++;
 561         /* This is racy, but the counter is approximate anyway. */
 562         if (events_check_enabled)
 563                 ws->wakeup_count++;
 564
 565         if (!ws->active)
 566                 wakeup_source_activate(ws);
 567 }
 568
 569 /**
 570  * __pm_stay_awake - Notify the PM core of a wakeup event.
 571  * @ws: Wakeup source object associated with the source of the event.
 572  *
 573  * It is safe to call this function from interrupt context.
 574  */
 575 void __pm_stay_awake(struct wakeup_source *ws)
 576 {
 577         unsigned long flags;
 578
 579         if (!ws)
 580                 return;
 581
 582         spin_lock_irqsave(&ws->lock, flags);
 583
 584         wakeup_source_report_event(ws);
 585         del_timer(&ws->timer);
 586         ws->timer_expires = 0;
 587
 588         spin_unlock_irqrestore(&ws->lock, flags);
 589 }
 590 EXPORT_SYMBOL_GPL(__pm_stay_awake);
 591
 592 /**
 593  * pm_stay_awake - Notify the PM core that a wakeup event is being processed.
 594  * @dev: Device the wakeup event is related to.
 595  *
 596  * Notify the PM core of a wakeup event (signaled by @dev) by calling
 597  * __pm_stay_awake for the @dev's wakeup source object.
 598  *
 599  * Call this function after detecting of a wakeup event if pm_relax() is going
 600  * to be called directly after processing the event (and possibly passing it to
 601  * user space for further processing).
 602  */
 603 void pm_stay_awake(struct device *dev)
 604 {
 605         unsigned long flags;
 606
 607         if (!dev)
 608                 return;
 609
 610         spin_lock_irqsave(&dev->power.lock, flags);
 611         __pm_stay_awake(dev->power.wakeup);
 612         spin_unlock_irqrestore(&dev->power.lock, flags);
 613 }
 614 EXPORT_SYMBOL_GPL(pm_stay_awake);
 615
 616 #ifdef CONFIG_PM_AUTOSLEEP
 617 static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now)
 618 {
 619         ktime_t delta = ktime_sub(now, ws->start_prevent_time);
 620         ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta);
 621 }
 622 #else
 623 static inline void update_prevent_sleep_time(struct wakeup_source *ws,
 624                                              ktime_t now) {}
 625 #endif
 626
 627 /**
 628  * wakup_source_deactivate - Mark given wakeup source as inactive.
 629  * @ws: Wakeup source to handle.
 630  *
 631  * Update the @ws' statistics and notify the PM core that the wakeup source has
 632  * become inactive by decrementing the counter of wakeup events being processed
 633  * and incrementing the counter of registered wakeup events.
 634  */
 635 static void wakeup_source_deactivate(struct wakeup_source *ws)
 636 {
 637         unsigned int cnt, inpr, cec;
 638         ktime_t duration;
 639         ktime_t now;
 640
 641         ws->relax_count++;
 642         /*
 643          * __pm_relax() may be called directly or from a timer function.
 644          * If it is called directly right after the timer function has been
 645          * started, but before the timer function calls __pm_relax(), it is
 646          * possible that __pm_stay_awake() will be called in the meantime and
 647          * will set ws->active.  Then, ws->active may be cleared immediately
 648          * by the __pm_relax() called from the timer function, but in such a
 649          * case ws->relax_count will be different from ws->active_count.
 650          */
 651         if (ws->relax_count != ws->active_count) {
 652                 ws->relax_count--;
 653                 return;
 654         }
 655
 656         ws->active = false;
 657
 658         now = ktime_get();
 659         duration = ktime_sub(now, ws->last_time);
 660         ws->total_time = ktime_add(ws->total_time, duration);
 661         if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time))
 662                 ws->max_time = duration;
 663
 664         ws->last_time = now;
 665         del_timer(&ws->timer);
 666         ws->timer_expires = 0;
 667
 668         if (ws->autosleep_enabled)
 669                 update_prevent_sleep_time(ws, now);
 670
 671         /*
 672          * Increment the counter of registered wakeup events and decrement the
 673          * couter of wakeup events in progress simultaneously.
 674          */
 675         cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count);
 676         trace_wakeup_source_deactivate(ws->name, cec);
 677
 678         split_counters(&cnt, &inpr);
 679         if (!inpr && waitqueue_active(&wakeup_count_wait_queue))
 680                 wake_up(&wakeup_count_wait_queue);
 681 }
 682
 683 /**
 684  * __pm_relax - Notify the PM core that processing of a wakeup event has ended.
 685  * @ws: Wakeup source object associated with the source of the event.
 686  *
 687  * Call this function for wakeup events whose processing started with calling
 688  * __pm_stay_awake().
 689  *
 690  * It is safe to call it from interrupt context.
 691  */
 692 void __pm_relax(struct wakeup_source *ws)
 693 {
 694         unsigned long flags;
 695
 696         if (!ws)
 697                 return;
 698
 699         spin_lock_irqsave(&ws->lock, flags);
 700         if (ws->active)
 701                 wakeup_source_deactivate(ws);
 702         spin_unlock_irqrestore(&ws->lock, flags);
 703 }
 704 EXPORT_SYMBOL_GPL(__pm_relax);
 705
 706 /**
 707  * pm_relax - Notify the PM core that processing of a wakeup event has ended.
 708  * @dev: Device that signaled the event.
 709  *
 710  * Execute __pm_relax() for the @dev's wakeup source object.
 711  */
 712 void pm_relax(struct device *dev)
 713 {
 714         unsigned long flags;
 715
 716         if (!dev)
 717                 return;
 718
 719         spin_lock_irqsave(&dev->power.lock, flags);
 720         __pm_relax(dev->power.wakeup);
 721         spin_unlock_irqrestore(&dev->power.lock, flags);
 722 }
 723 EXPORT_SYMBOL_GPL(pm_relax);
 724
 725 /**
 726  * pm_wakeup_timer_fn - Delayed finalization of a wakeup event.
 727  * @data: Address of the wakeup source object associated with the event source.
 728  *
 729  * Call wakeup_source_deactivate() for the wakeup source whose address is stored
 730  * in @data if it is currently active and its timer has not been canceled and
 731  * the expiration time of the timer is not in future.
 732  */
 733 static void pm_wakeup_timer_fn(unsigned long data)
 734 {
 735         struct wakeup_source *ws = (struct wakeup_source *)data;
 736         unsigned long flags;
 737
 738         spin_lock_irqsave(&ws->lock, flags);
 739
 740         if (ws->active && ws->timer_expires
 741             && time_after_eq(jiffies, ws->timer_expires)) {
 742                 wakeup_source_deactivate(ws);
 743                 ws->expire_count++;
 744         }
 745
 746         spin_unlock_irqrestore(&ws->lock, flags);
 747 }
 748
 749 /**
 750  * __pm_wakeup_event - Notify the PM core of a wakeup event.
 751  * @ws: Wakeup source object associated with the event source.
 752  * @msec: Anticipated event processing time (in milliseconds).
 753  *
 754  * Notify the PM core of a wakeup event whose source is @ws that will take
 755  * approximately @msec milliseconds to be processed by the kernel.  If @ws is
 756  * not active, activate it.  If @msec is nonzero, set up the @ws' timer to
 757  * execute pm_wakeup_timer_fn() in future.
 758  *
 759  * It is safe to call this function from interrupt context.
 760  */
 761 void __pm_wakeup_event(struct wakeup_source *ws, unsigned int msec)
 762 {
 763         unsigned long flags;
 764         unsigned long expires;
 765
 766         if (!ws)
 767                 return;
 768
 769         spin_lock_irqsave(&ws->lock, flags);
 770
 771         wakeup_source_report_event(ws);
 772
 773         if (!msec) {
 774                 wakeup_source_deactivate(ws);
 775                 goto unlock;
 776         }
 777
 778         expires = jiffies + msecs_to_jiffies(msec);
 779         if (!expires)
 780                 expires = 1;
 781
 782         if (!ws->timer_expires || time_after(expires, ws->timer_expires)) {
 783                 mod_timer(&ws->timer, expires);
 784                 ws->timer_expires = expires;
 785         }
 786
 787  unlock:
 788         spin_unlock_irqrestore(&ws->lock, flags);
 789 }
 790 EXPORT_SYMBOL_GPL(__pm_wakeup_event);
 791
 792
 793 /**
 794  * pm_wakeup_event - Notify the PM core of a wakeup event.
 795  * @dev: Device the wakeup event is related to.
 796  * @msec: Anticipated event processing time (in milliseconds).
 797  *
 798  * Call __pm_wakeup_event() for the @dev's wakeup source object.
 799  */
 800 void pm_wakeup_event(struct device *dev, unsigned int msec)
 801 {
 802         unsigned long flags;
 803
 804         if (!dev)
 805                 return;
 806
 807         spin_lock_irqsave(&dev->power.lock, flags);
 808         __pm_wakeup_event(dev->power.wakeup, msec);
 809         spin_unlock_irqrestore(&dev->power.lock, flags);
 810 }
 811 EXPORT_SYMBOL_GPL(pm_wakeup_event);
 812
 813 void pm_print_active_wakeup_sources(void)
 814 {
 815         struct wakeup_source *ws;
 816         int srcuidx, active = 0;
 817         struct wakeup_source *last_activity_ws = NULL;
 818
 819         srcuidx = srcu_read_lock(&wakeup_srcu);
 820         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 821                 if (ws->active) {
 822                         pr_info("active wakeup source: %s\n", ws->name);
 823                         active = 1;
 824                 } else if (!active &&
 825                            (!last_activity_ws ||
 826                             ktime_to_ns(ws->last_time) >
 827                             ktime_to_ns(last_activity_ws->last_time))) {
 828                         last_activity_ws = ws;
 829                 }
 830         }
 831
 832         if (!active && last_activity_ws)
 833                 pr_info("last active wakeup source: %s\n",
 834                         last_activity_ws->name);
 835         srcu_read_unlock(&wakeup_srcu, srcuidx);
 836 }
 837 EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources);
 838
 839 /**
 840  * pm_wakeup_pending - Check if power transition in progress should be aborted.
 841  *
 842  * Compare the current number of registered wakeup events with its preserved
 843  * value from the past and return true if new wakeup events have been registered
 844  * since the old value was stored.  Also return true if the current number of
 845  * wakeup events being processed is different from zero.
 846  */
 847 bool pm_wakeup_pending(void)
 848 {
 849         unsigned long flags;
 850         bool ret = false;
 851
 852         spin_lock_irqsave(&events_lock, flags);
 853         if (events_check_enabled) {
 854                 unsigned int cnt, inpr;
 855
 856                 split_counters(&cnt, &inpr);
 857                 ret = (cnt != saved_count || inpr > 0);
 858                 events_check_enabled = !ret;
 859         }
 860         spin_unlock_irqrestore(&events_lock, flags);
 861
 862         if (ret) {
 863                 pr_info("PM: Wakeup pending, aborting suspend\n");
 864                 pm_print_active_wakeup_sources();
 865         }
 866
 867         return ret || pm_abort_suspend;
 868 }
 869
 870 void pm_system_wakeup(void)
 871 {
 872         pm_abort_suspend = true;
 873         freeze_wake();
 874 }
 875 EXPORT_SYMBOL_GPL(pm_system_wakeup);
 876
 877 void pm_wakeup_clear(void)
 878 {
 879         pm_abort_suspend = false;
 880         pm_wakeup_irq = 0;
 881 }
 882
 883 void pm_system_irq_wakeup(unsigned int irq_number)
 884 {
 885         if (pm_wakeup_irq == 0) {
 886                 pm_wakeup_irq = irq_number;
 887                 pm_system_wakeup();
 888         }
 889 }
 890
 891 /**
 892  * pm_get_wakeup_count - Read the number of registered wakeup events.
 893  * @count: Address to store the value at.
 894  * @block: Whether or not to block.
 895  *
 896  * Store the number of registered wakeup events at the address in @count.  If
 897  * @block is set, block until the current number of wakeup events being
 898  * processed is zero.
 899  *
 900  * Return 'false' if the current number of wakeup events being processed is
 901  * nonzero.  Otherwise return 'true'.
 902  */
 903 bool pm_get_wakeup_count(unsigned int *count, bool block)
 904 {
 905         unsigned int cnt, inpr;
 906
 907         if (block) {
 908                 DEFINE_WAIT(wait);
 909
 910                 for (;;) {
 911                         prepare_to_wait(&wakeup_count_wait_queue, &wait,
 912                                         TASK_INTERRUPTIBLE);
 913                         split_counters(&cnt, &inpr);
 914                         if (inpr == 0 || signal_pending(current))
 915                                 break;
 916
 917                         schedule();
 918                 }
 919                 finish_wait(&wakeup_count_wait_queue, &wait);
 920         }
 921
 922         split_counters(&cnt, &inpr);
 923         *count = cnt;
 924         return !inpr;
 925 }
 926
 927 /**
 928  * pm_save_wakeup_count - Save the current number of registered wakeup events.
 929  * @count: Value to compare with the current number of registered wakeup events.
 930  *
 931  * If @count is equal to the current number of registered wakeup events and the
 932  * current number of wakeup events being processed is zero, store @count as the
 933  * old number of registered wakeup events for pm_check_wakeup_events(), enable
 934  * wakeup events detection and return 'true'.  Otherwise disable wakeup events
 935  * detection and return 'false'.
 936  */
 937 bool pm_save_wakeup_count(unsigned int count)
 938 {
 939         unsigned int cnt, inpr;
 940         unsigned long flags;
 941
 942         events_check_enabled = false;
 943         spin_lock_irqsave(&events_lock, flags);
 944         split_counters(&cnt, &inpr);
 945         if (cnt == count && inpr == 0) {
 946                 saved_count = count;
 947                 events_check_enabled = true;
 948         }
 949         spin_unlock_irqrestore(&events_lock, flags);
 950         return events_check_enabled;
 951 }
 952
 953 #ifdef CONFIG_PM_AUTOSLEEP
 954 /**
 955  * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources.
 956  * @enabled: Whether to set or to clear the autosleep_enabled flags.
 957  */
 958 void pm_wakep_autosleep_enabled(bool set)
 959 {
 960         struct wakeup_source *ws;
 961         ktime_t now = ktime_get();
 962         int srcuidx;
 963
 964         srcuidx = srcu_read_lock(&wakeup_srcu);
 965         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 966                 spin_lock_irq(&ws->lock);
 967                 if (ws->autosleep_enabled != set) {
 968                         ws->autosleep_enabled = set;
 969                         if (ws->active) {
 970                                 if (set)
 971                                         ws->start_prevent_time = now;
 972                                 else
 973                                         update_prevent_sleep_time(ws, now);
 974                         }
 975                 }
 976                 spin_unlock_irq(&ws->lock);
 977         }
 978         srcu_read_unlock(&wakeup_srcu, srcuidx);
 979 }
 980 #endif /* CONFIG_PM_AUTOSLEEP */
 981
 982 static struct dentry *wakeup_sources_stats_dentry;
 983
 984 /**
 985  * print_wakeup_source_stats - Print wakeup source statistics information.
 986  * @m: seq_file to print the statistics into.
 987  * @ws: Wakeup source object to print the statistics for.
 988  */
 989 static int print_wakeup_source_stats(struct seq_file *m,
 990                                      struct wakeup_source *ws)
 991 {
 992         unsigned long flags;
 993         ktime_t total_time;
 994         ktime_t max_time;
 995         unsigned long active_count;
 996         ktime_t active_time;
 997         ktime_t prevent_sleep_time;
 998
 999         spin_lock_irqsave(&ws->lock, flags);
1000
1001         total_time = ws->total_time;
1002         max_time = ws->max_time;
1003         prevent_sleep_time = ws->prevent_sleep_time;
1004         active_count = ws->active_count;
1005         if (ws->active) {
1006                 ktime_t now = ktime_get();
1007
1008                 active_time = ktime_sub(now, ws->last_time);
1009                 total_time = ktime_add(total_time, active_time);
1010                 if (active_time.tv64 > max_time.tv64)
1011                         max_time = active_time;
1012
1013                 if (ws->autosleep_enabled)
1014                         prevent_sleep_time = ktime_add(prevent_sleep_time,
1015                                 ktime_sub(now, ws->start_prevent_time));
1016         } else {
1017                 active_time = ktime_set(0, 0);
1018         }
1019
1020         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",
1021                    ws->name, active_count, ws->event_count,
1022                    ws->wakeup_count, ws->expire_count,
1023                    ktime_to_ms(active_time), ktime_to_ms(total_time),
1024                    ktime_to_ms(max_time), ktime_to_ms(ws->last_time),
1025                    ktime_to_ms(prevent_sleep_time));
1026
1027         spin_unlock_irqrestore(&ws->lock, flags);
1028
1029         return 0;
1030 }
1031
1032 /**
1033  * wakeup_sources_stats_show - Print wakeup sources statistics information.
1034  * @m: seq_file to print the statistics into.
1035  */
1036 static int wakeup_sources_stats_show(struct seq_file *m, void *unused)
1037 {
1038         struct wakeup_source *ws;
1039         int srcuidx;
1040
1041         seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t"
1042                 "expire_count\tactive_since\ttotal_time\tmax_time\t"
1043                 "last_change\tprevent_suspend_time\n");
1044
1045         srcuidx = srcu_read_lock(&wakeup_srcu);
1046         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
1047                 print_wakeup_source_stats(m, ws);
1048         srcu_read_unlock(&wakeup_srcu, srcuidx);
1049
1050         print_wakeup_source_stats(m, &deleted_ws);
1051
1052         return 0;
1053 }
1054
1055 static int wakeup_sources_stats_open(struct inode *inode, struct file *file)
1056 {
1057         return single_open(file, wakeup_sources_stats_show, NULL);
1058 }
1059
1060 static const struct file_operations wakeup_sources_stats_fops = {
1061         .owner = THIS_MODULE,
1062         .open = wakeup_sources_stats_open,
1063         .read = seq_read,
1064         .llseek = seq_lseek,
1065         .release = single_release,
1066 };
1067
1068 static int __init wakeup_sources_debugfs_init(void)
1069 {
1070         wakeup_sources_stats_dentry = debugfs_create_file("wakeup_sources",
1071                         S_IRUGO, NULL, NULL, &wakeup_sources_stats_fops);
1072         return 0;
1073 }
1074
1075 postcore_initcall(wakeup_sources_debugfs_init);