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