drivers/base/power/wakeup.c

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This source file includes following definitions.
split_counters
wakeup_source_create
wakeup_source_record
wakeup_source_free
wakeup_source_destroy
wakeup_source_add
wakeup_source_remove
wakeup_source_register
wakeup_source_unregister
device_wakeup_attach
device_wakeup_enable
device_wakeup_attach_irq
device_wakeup_detach_irq
device_wakeup_arm_wake_irqs
device_wakeup_disarm_wake_irqs
device_wakeup_detach
device_wakeup_disable
device_set_wakeup_capable
device_init_wakeup
device_set_wakeup_enable
wakeup_source_not_registered
wakeup_source_activate
wakeup_source_report_event
__pm_stay_awake
pm_stay_awake
update_prevent_sleep_time
update_prevent_sleep_time
wakeup_source_deactivate
__pm_relax
pm_relax
pm_wakeup_timer_fn
pm_wakeup_ws_event
pm_wakeup_dev_event
pm_print_active_wakeup_sources
pm_wakeup_pending
pm_system_wakeup
pm_system_cancel_wakeup
pm_wakeup_clear
pm_system_irq_wakeup
pm_get_wakeup_count
pm_save_wakeup_count
pm_wakep_autosleep_enabled
print_wakeup_source_stats
wakeup_sources_stats_seq_start
wakeup_sources_stats_seq_next
wakeup_sources_stats_seq_stop
wakeup_sources_stats_seq_show
wakeup_sources_stats_open
wakeup_sources_debugfs_init
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * drivers/base/power/wakeup.c - System wakeup events framework
   4  *
   5  * Copyright (c) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
   6  */
   7 #define pr_fmt(fmt) "PM: " fmt
   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 #ifndef CONFIG_SUSPEND
  23 suspend_state_t pm_suspend_target_state;
  24 #define pm_suspend_target_state (PM_SUSPEND_ON)
  25 #endif
  26 
  27 /*
  28  * If set, the suspend/hibernate code will abort transitions to a sleep state
  29  * if wakeup events are registered during or immediately before the transition.
  30  */
  31 bool events_check_enabled __read_mostly;
  32 
  33 /* First wakeup IRQ seen by the kernel in the last cycle. */
  34 unsigned int pm_wakeup_irq __read_mostly;
  35 
  36 /* If greater than 0 and the system is suspending, terminate the suspend. */
  37 static atomic_t pm_abort_suspend __read_mostly;
  38 
  39 /*
  40  * Combined counters of registered wakeup events and wakeup events in progress.
  41  * They need to be modified together atomically, so it's better to use one
  42  * atomic variable to hold them both.
  43  */
  44 static atomic_t combined_event_count = ATOMIC_INIT(0);
  45 
  46 #define IN_PROGRESS_BITS        (sizeof(int) * 4)
  47 #define MAX_IN_PROGRESS         ((1 << IN_PROGRESS_BITS) - 1)
  48 
  49 static void split_counters(unsigned int *cnt, unsigned int *inpr)
  50 {
  51         unsigned int comb = atomic_read(&combined_event_count);
  52 
  53         *cnt = (comb >> IN_PROGRESS_BITS);
  54         *inpr = comb & MAX_IN_PROGRESS;
  55 }
  56 
  57 /* A preserved old value of the events counter. */
  58 static unsigned int saved_count;
  59 
  60 static DEFINE_RAW_SPINLOCK(events_lock);
  61 
  62 static void pm_wakeup_timer_fn(struct timer_list *t);
  63 
  64 static LIST_HEAD(wakeup_sources);
  65 
  66 static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue);
  67 
  68 DEFINE_STATIC_SRCU(wakeup_srcu);
  69 
  70 static struct wakeup_source deleted_ws = {
  71         .name = "deleted",
  72         .lock =  __SPIN_LOCK_UNLOCKED(deleted_ws.lock),
  73 };
  74 
  75 static DEFINE_IDA(wakeup_ida);
  76 
  77 /**
  78  * wakeup_source_create - Create a struct wakeup_source object.
  79  * @name: Name of the new wakeup source.
  80  */
  81 struct wakeup_source *wakeup_source_create(const char *name)
  82 {
  83         struct wakeup_source *ws;
  84         const char *ws_name;
  85         int id;
  86 
  87         ws = kzalloc(sizeof(*ws), GFP_KERNEL);
  88         if (!ws)
  89                 goto err_ws;
  90 
  91         ws_name = kstrdup_const(name, GFP_KERNEL);
  92         if (!ws_name)
  93                 goto err_name;
  94         ws->name = ws_name;
  95 
  96         id = ida_alloc(&wakeup_ida, GFP_KERNEL);
  97         if (id < 0)
  98                 goto err_id;
  99         ws->id = id;
 100 
 101         return ws;
 102 
 103 err_id:
 104         kfree_const(ws->name);
 105 err_name:
 106         kfree(ws);
 107 err_ws:
 108         return NULL;
 109 }
 110 EXPORT_SYMBOL_GPL(wakeup_source_create);
 111 
 112 /*
 113  * Record wakeup_source statistics being deleted into a dummy wakeup_source.
 114  */
 115 static void wakeup_source_record(struct wakeup_source *ws)
 116 {
 117         unsigned long flags;
 118 
 119         spin_lock_irqsave(&deleted_ws.lock, flags);
 120 
 121         if (ws->event_count) {
 122                 deleted_ws.total_time =
 123                         ktime_add(deleted_ws.total_time, ws->total_time);
 124                 deleted_ws.prevent_sleep_time =
 125                         ktime_add(deleted_ws.prevent_sleep_time,
 126                                   ws->prevent_sleep_time);
 127                 deleted_ws.max_time =
 128                         ktime_compare(deleted_ws.max_time, ws->max_time) > 0 ?
 129                                 deleted_ws.max_time : ws->max_time;
 130                 deleted_ws.event_count += ws->event_count;
 131                 deleted_ws.active_count += ws->active_count;
 132                 deleted_ws.relax_count += ws->relax_count;
 133                 deleted_ws.expire_count += ws->expire_count;
 134                 deleted_ws.wakeup_count += ws->wakeup_count;
 135         }
 136 
 137         spin_unlock_irqrestore(&deleted_ws.lock, flags);
 138 }
 139 
 140 static void wakeup_source_free(struct wakeup_source *ws)
 141 {
 142         ida_free(&wakeup_ida, ws->id);
 143         kfree_const(ws->name);
 144         kfree(ws);
 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         __pm_relax(ws);
 159         wakeup_source_record(ws);
 160         wakeup_source_free(ws);
 161 }
 162 EXPORT_SYMBOL_GPL(wakeup_source_destroy);
 163 
 164 /**
 165  * wakeup_source_add - Add given object to the list of wakeup sources.
 166  * @ws: Wakeup source object to add to the list.
 167  */
 168 void wakeup_source_add(struct wakeup_source *ws)
 169 {
 170         unsigned long flags;
 171 
 172         if (WARN_ON(!ws))
 173                 return;
 174 
 175         spin_lock_init(&ws->lock);
 176         timer_setup(&ws->timer, pm_wakeup_timer_fn, 0);
 177         ws->active = false;
 178 
 179         raw_spin_lock_irqsave(&events_lock, flags);
 180         list_add_rcu(&ws->entry, &wakeup_sources);
 181         raw_spin_unlock_irqrestore(&events_lock, flags);
 182 }
 183 EXPORT_SYMBOL_GPL(wakeup_source_add);
 184 
 185 /**
 186  * wakeup_source_remove - Remove given object from the wakeup sources list.
 187  * @ws: Wakeup source object to remove from the list.
 188  */
 189 void wakeup_source_remove(struct wakeup_source *ws)
 190 {
 191         unsigned long flags;
 192 
 193         if (WARN_ON(!ws))
 194                 return;
 195 
 196         raw_spin_lock_irqsave(&events_lock, flags);
 197         list_del_rcu(&ws->entry);
 198         raw_spin_unlock_irqrestore(&events_lock, flags);
 199         synchronize_srcu(&wakeup_srcu);
 200 
 201         del_timer_sync(&ws->timer);
 202         /*
 203          * Clear timer.function to make wakeup_source_not_registered() treat
 204          * this wakeup source as not registered.
 205          */
 206         ws->timer.function = NULL;
 207 }
 208 EXPORT_SYMBOL_GPL(wakeup_source_remove);
 209 
 210 /**
 211  * wakeup_source_register - Create wakeup source and add it to the list.
 212  * @dev: Device this wakeup source is associated with (or NULL if virtual).
 213  * @name: Name of the wakeup source to register.
 214  */
 215 struct wakeup_source *wakeup_source_register(struct device *dev,
 216                                              const char *name)
 217 {
 218         struct wakeup_source *ws;
 219         int ret;
 220 
 221         ws = wakeup_source_create(name);
 222         if (ws) {
 223                 if (!dev || device_is_registered(dev)) {
 224                         ret = wakeup_source_sysfs_add(dev, ws);
 225                         if (ret) {
 226                                 wakeup_source_free(ws);
 227                                 return NULL;
 228                         }
 229                 }
 230                 wakeup_source_add(ws);
 231         }
 232         return ws;
 233 }
 234 EXPORT_SYMBOL_GPL(wakeup_source_register);
 235 
 236 /**
 237  * wakeup_source_unregister - Remove wakeup source from the list and remove it.
 238  * @ws: Wakeup source object to unregister.
 239  */
 240 void wakeup_source_unregister(struct wakeup_source *ws)
 241 {
 242         if (ws) {
 243                 wakeup_source_remove(ws);
 244                 if (ws->dev)
 245                         wakeup_source_sysfs_remove(ws);
 246 
 247                 wakeup_source_destroy(ws);
 248         }
 249 }
 250 EXPORT_SYMBOL_GPL(wakeup_source_unregister);
 251 
 252 /**
 253  * device_wakeup_attach - Attach a wakeup source object to a device object.
 254  * @dev: Device to handle.
 255  * @ws: Wakeup source object to attach to @dev.
 256  *
 257  * This causes @dev to be treated as a wakeup device.
 258  */
 259 static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws)
 260 {
 261         spin_lock_irq(&dev->power.lock);
 262         if (dev->power.wakeup) {
 263                 spin_unlock_irq(&dev->power.lock);
 264                 return -EEXIST;
 265         }
 266         dev->power.wakeup = ws;
 267         if (dev->power.wakeirq)
 268                 device_wakeup_attach_irq(dev, dev->power.wakeirq);
 269         spin_unlock_irq(&dev->power.lock);
 270         return 0;
 271 }
 272 
 273 /**
 274  * device_wakeup_enable - Enable given device to be a wakeup source.
 275  * @dev: Device to handle.
 276  *
 277  * Create a wakeup source object, register it and attach it to @dev.
 278  */
 279 int device_wakeup_enable(struct device *dev)
 280 {
 281         struct wakeup_source *ws;
 282         int ret;
 283 
 284         if (!dev || !dev->power.can_wakeup)
 285                 return -EINVAL;
 286 
 287         if (pm_suspend_target_state != PM_SUSPEND_ON)
 288                 dev_dbg(dev, "Suspicious %s() during system transition!\n", __func__);
 289 
 290         ws = wakeup_source_register(dev, dev_name(dev));
 291         if (!ws)
 292                 return -ENOMEM;
 293 
 294         ret = device_wakeup_attach(dev, ws);
 295         if (ret)
 296                 wakeup_source_unregister(ws);
 297 
 298         return ret;
 299 }
 300 EXPORT_SYMBOL_GPL(device_wakeup_enable);
 301 
 302 /**
 303  * device_wakeup_attach_irq - Attach a wakeirq to a wakeup source
 304  * @dev: Device to handle
 305  * @wakeirq: Device specific wakeirq entry
 306  *
 307  * Attach a device wakeirq to the wakeup source so the device
 308  * wake IRQ can be configured automatically for suspend and
 309  * resume.
 310  *
 311  * Call under the device's power.lock lock.
 312  */
 313 void device_wakeup_attach_irq(struct device *dev,
 314                              struct wake_irq *wakeirq)
 315 {
 316         struct wakeup_source *ws;
 317 
 318         ws = dev->power.wakeup;
 319         if (!ws)
 320                 return;
 321 
 322         if (ws->wakeirq)
 323                 dev_err(dev, "Leftover wakeup IRQ found, overriding\n");
 324 
 325         ws->wakeirq = wakeirq;
 326 }
 327 
 328 /**
 329  * device_wakeup_detach_irq - Detach a wakeirq from a wakeup source
 330  * @dev: Device to handle
 331  *
 332  * Removes a device wakeirq from the wakeup source.
 333  *
 334  * Call under the device's power.lock lock.
 335  */
 336 void device_wakeup_detach_irq(struct device *dev)
 337 {
 338         struct wakeup_source *ws;
 339 
 340         ws = dev->power.wakeup;
 341         if (ws)
 342                 ws->wakeirq = NULL;
 343 }
 344 
 345 /**
 346  * device_wakeup_arm_wake_irqs(void)
 347  *
 348  * Itereates over the list of device wakeirqs to arm them.
 349  */
 350 void device_wakeup_arm_wake_irqs(void)
 351 {
 352         struct wakeup_source *ws;
 353         int srcuidx;
 354 
 355         srcuidx = srcu_read_lock(&wakeup_srcu);
 356         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
 357                 dev_pm_arm_wake_irq(ws->wakeirq);
 358         srcu_read_unlock(&wakeup_srcu, srcuidx);
 359 }
 360 
 361 /**
 362  * device_wakeup_disarm_wake_irqs(void)
 363  *
 364  * Itereates over the list of device wakeirqs to disarm them.
 365  */
 366 void device_wakeup_disarm_wake_irqs(void)
 367 {
 368         struct wakeup_source *ws;
 369         int srcuidx;
 370 
 371         srcuidx = srcu_read_lock(&wakeup_srcu);
 372         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
 373                 dev_pm_disarm_wake_irq(ws->wakeirq);
 374         srcu_read_unlock(&wakeup_srcu, srcuidx);
 375 }
 376 
 377 /**
 378  * device_wakeup_detach - Detach a device's wakeup source object from it.
 379  * @dev: Device to detach the wakeup source object from.
 380  *
 381  * After it returns, @dev will not be treated as a wakeup device any more.
 382  */
 383 static struct wakeup_source *device_wakeup_detach(struct device *dev)
 384 {
 385         struct wakeup_source *ws;
 386 
 387         spin_lock_irq(&dev->power.lock);
 388         ws = dev->power.wakeup;
 389         dev->power.wakeup = NULL;
 390         spin_unlock_irq(&dev->power.lock);
 391         return ws;
 392 }
 393 
 394 /**
 395  * device_wakeup_disable - Do not regard a device as a wakeup source any more.
 396  * @dev: Device to handle.
 397  *
 398  * Detach the @dev's wakeup source object from it, unregister this wakeup source
 399  * object and destroy it.
 400  */
 401 int device_wakeup_disable(struct device *dev)
 402 {
 403         struct wakeup_source *ws;
 404 
 405         if (!dev || !dev->power.can_wakeup)
 406                 return -EINVAL;
 407 
 408         ws = device_wakeup_detach(dev);
 409         wakeup_source_unregister(ws);
 410         return 0;
 411 }
 412 EXPORT_SYMBOL_GPL(device_wakeup_disable);
 413 
 414 /**
 415  * device_set_wakeup_capable - Set/reset device wakeup capability flag.
 416  * @dev: Device to handle.
 417  * @capable: Whether or not @dev is capable of waking up the system from sleep.
 418  *
 419  * If @capable is set, set the @dev's power.can_wakeup flag and add its
 420  * wakeup-related attributes to sysfs.  Otherwise, unset the @dev's
 421  * power.can_wakeup flag and remove its wakeup-related attributes from sysfs.
 422  *
 423  * This function may sleep and it can't be called from any context where
 424  * sleeping is not allowed.
 425  */
 426 void device_set_wakeup_capable(struct device *dev, bool capable)
 427 {
 428         if (!!dev->power.can_wakeup == !!capable)
 429                 return;
 430 
 431         dev->power.can_wakeup = capable;
 432         if (device_is_registered(dev) && !list_empty(&dev->power.entry)) {
 433                 if (capable) {
 434                         int ret = wakeup_sysfs_add(dev);
 435 
 436                         if (ret)
 437                                 dev_info(dev, "Wakeup sysfs attributes not added\n");
 438                 } else {
 439                         wakeup_sysfs_remove(dev);
 440                 }
 441         }
 442 }
 443 EXPORT_SYMBOL_GPL(device_set_wakeup_capable);
 444 
 445 /**
 446  * device_init_wakeup - Device wakeup initialization.
 447  * @dev: Device to handle.
 448  * @enable: Whether or not to enable @dev as a wakeup device.
 449  *
 450  * By default, most devices should leave wakeup disabled.  The exceptions are
 451  * devices that everyone expects to be wakeup sources: keyboards, power buttons,
 452  * possibly network interfaces, etc.  Also, devices that don't generate their
 453  * own wakeup requests but merely forward requests from one bus to another
 454  * (like PCI bridges) should have wakeup enabled by default.
 455  */
 456 int device_init_wakeup(struct device *dev, bool enable)
 457 {
 458         int ret = 0;
 459 
 460         if (!dev)
 461                 return -EINVAL;
 462 
 463         if (enable) {
 464                 device_set_wakeup_capable(dev, true);
 465                 ret = device_wakeup_enable(dev);
 466         } else {
 467                 device_wakeup_disable(dev);
 468                 device_set_wakeup_capable(dev, false);
 469         }
 470 
 471         return ret;
 472 }
 473 EXPORT_SYMBOL_GPL(device_init_wakeup);
 474 
 475 /**
 476  * device_set_wakeup_enable - Enable or disable a device to wake up the system.
 477  * @dev: Device to handle.
 478  */
 479 int device_set_wakeup_enable(struct device *dev, bool enable)
 480 {
 481         return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev);
 482 }
 483 EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
 484 
 485 /**
 486  * wakeup_source_not_registered - validate the given wakeup source.
 487  * @ws: Wakeup source to be validated.
 488  */
 489 static bool wakeup_source_not_registered(struct wakeup_source *ws)
 490 {
 491         /*
 492          * Use timer struct to check if the given source is initialized
 493          * by wakeup_source_add.
 494          */
 495         return ws->timer.function != pm_wakeup_timer_fn;
 496 }
 497 
 498 /*
 499  * The functions below use the observation that each wakeup event starts a
 500  * period in which the system should not be suspended.  The moment this period
 501  * will end depends on how the wakeup event is going to be processed after being
 502  * detected and all of the possible cases can be divided into two distinct
 503  * groups.
 504  *
 505  * First, a wakeup event may be detected by the same functional unit that will
 506  * carry out the entire processing of it and possibly will pass it to user space
 507  * for further processing.  In that case the functional unit that has detected
 508  * the event may later "close" the "no suspend" period associated with it
 509  * directly as soon as it has been dealt with.  The pair of pm_stay_awake() and
 510  * pm_relax(), balanced with each other, is supposed to be used in such
 511  * situations.
 512  *
 513  * Second, a wakeup event may be detected by one functional unit and processed
 514  * by another one.  In that case the unit that has detected it cannot really
 515  * "close" the "no suspend" period associated with it, unless it knows in
 516  * advance what's going to happen to the event during processing.  This
 517  * knowledge, however, may not be available to it, so it can simply specify time
 518  * to wait before the system can be suspended and pass it as the second
 519  * argument of pm_wakeup_event().
 520  *
 521  * It is valid to call pm_relax() after pm_wakeup_event(), in which case the
 522  * "no suspend" period will be ended either by the pm_relax(), or by the timer
 523  * function executed when the timer expires, whichever comes first.
 524  */
 525 
 526 /**
 527  * wakup_source_activate - Mark given wakeup source as active.
 528  * @ws: Wakeup source to handle.
 529  *
 530  * Update the @ws' statistics and, if @ws has just been activated, notify the PM
 531  * core of the event by incrementing the counter of of wakeup events being
 532  * processed.
 533  */
 534 static void wakeup_source_activate(struct wakeup_source *ws)
 535 {
 536         unsigned int cec;
 537 
 538         if (WARN_ONCE(wakeup_source_not_registered(ws),
 539                         "unregistered wakeup source\n"))
 540                 return;
 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  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
 558  */
 559 static void wakeup_source_report_event(struct wakeup_source *ws, bool hard)
 560 {
 561         ws->event_count++;
 562         /* This is racy, but the counter is approximate anyway. */
 563         if (events_check_enabled)
 564                 ws->wakeup_count++;
 565 
 566         if (!ws->active)
 567                 wakeup_source_activate(ws);
 568 
 569         if (hard)
 570                 pm_system_wakeup();
 571 }
 572 
 573 /**
 574  * __pm_stay_awake - Notify the PM core of a wakeup event.
 575  * @ws: Wakeup source object associated with the source of the event.
 576  *
 577  * It is safe to call this function from interrupt context.
 578  */
 579 void __pm_stay_awake(struct wakeup_source *ws)
 580 {
 581         unsigned long flags;
 582 
 583         if (!ws)
 584                 return;
 585 
 586         spin_lock_irqsave(&ws->lock, flags);
 587 
 588         wakeup_source_report_event(ws, false);
 589         del_timer(&ws->timer);
 590         ws->timer_expires = 0;
 591 
 592         spin_unlock_irqrestore(&ws->lock, flags);
 593 }
 594 EXPORT_SYMBOL_GPL(__pm_stay_awake);
 595 
 596 /**
 597  * pm_stay_awake - Notify the PM core that a wakeup event is being processed.
 598  * @dev: Device the wakeup event is related to.
 599  *
 600  * Notify the PM core of a wakeup event (signaled by @dev) by calling
 601  * __pm_stay_awake for the @dev's wakeup source object.
 602  *
 603  * Call this function after detecting of a wakeup event if pm_relax() is going
 604  * to be called directly after processing the event (and possibly passing it to
 605  * user space for further processing).
 606  */
 607 void pm_stay_awake(struct device *dev)
 608 {
 609         unsigned long flags;
 610 
 611         if (!dev)
 612                 return;
 613 
 614         spin_lock_irqsave(&dev->power.lock, flags);
 615         __pm_stay_awake(dev->power.wakeup);
 616         spin_unlock_irqrestore(&dev->power.lock, flags);
 617 }
 618 EXPORT_SYMBOL_GPL(pm_stay_awake);
 619 
 620 #ifdef CONFIG_PM_AUTOSLEEP
 621 static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now)
 622 {
 623         ktime_t delta = ktime_sub(now, ws->start_prevent_time);
 624         ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta);
 625 }
 626 #else
 627 static inline void update_prevent_sleep_time(struct wakeup_source *ws,
 628                                              ktime_t now) {}
 629 #endif
 630 
 631 /**
 632  * wakup_source_deactivate - Mark given wakeup source as inactive.
 633  * @ws: Wakeup source to handle.
 634  *
 635  * Update the @ws' statistics and notify the PM core that the wakeup source has
 636  * become inactive by decrementing the counter of wakeup events being processed
 637  * and incrementing the counter of registered wakeup events.
 638  */
 639 static void wakeup_source_deactivate(struct wakeup_source *ws)
 640 {
 641         unsigned int cnt, inpr, cec;
 642         ktime_t duration;
 643         ktime_t now;
 644 
 645         ws->relax_count++;
 646         /*
 647          * __pm_relax() may be called directly or from a timer function.
 648          * If it is called directly right after the timer function has been
 649          * started, but before the timer function calls __pm_relax(), it is
 650          * possible that __pm_stay_awake() will be called in the meantime and
 651          * will set ws->active.  Then, ws->active may be cleared immediately
 652          * by the __pm_relax() called from the timer function, but in such a
 653          * case ws->relax_count will be different from ws->active_count.
 654          */
 655         if (ws->relax_count != ws->active_count) {
 656                 ws->relax_count--;
 657                 return;
 658         }
 659 
 660         ws->active = false;
 661 
 662         now = ktime_get();
 663         duration = ktime_sub(now, ws->last_time);
 664         ws->total_time = ktime_add(ws->total_time, duration);
 665         if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time))
 666                 ws->max_time = duration;
 667 
 668         ws->last_time = now;
 669         del_timer(&ws->timer);
 670         ws->timer_expires = 0;
 671 
 672         if (ws->autosleep_enabled)
 673                 update_prevent_sleep_time(ws, now);
 674 
 675         /*
 676          * Increment the counter of registered wakeup events and decrement the
 677          * couter of wakeup events in progress simultaneously.
 678          */
 679         cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count);
 680         trace_wakeup_source_deactivate(ws->name, cec);
 681 
 682         split_counters(&cnt, &inpr);
 683         if (!inpr && waitqueue_active(&wakeup_count_wait_queue))
 684                 wake_up(&wakeup_count_wait_queue);
 685 }
 686 
 687 /**
 688  * __pm_relax - Notify the PM core that processing of a wakeup event has ended.
 689  * @ws: Wakeup source object associated with the source of the event.
 690  *
 691  * Call this function for wakeup events whose processing started with calling
 692  * __pm_stay_awake().
 693  *
 694  * It is safe to call it from interrupt context.
 695  */
 696 void __pm_relax(struct wakeup_source *ws)
 697 {
 698         unsigned long flags;
 699 
 700         if (!ws)
 701                 return;
 702 
 703         spin_lock_irqsave(&ws->lock, flags);
 704         if (ws->active)
 705                 wakeup_source_deactivate(ws);
 706         spin_unlock_irqrestore(&ws->lock, flags);
 707 }
 708 EXPORT_SYMBOL_GPL(__pm_relax);
 709 
 710 /**
 711  * pm_relax - Notify the PM core that processing of a wakeup event has ended.
 712  * @dev: Device that signaled the event.
 713  *
 714  * Execute __pm_relax() for the @dev's wakeup source object.
 715  */
 716 void pm_relax(struct device *dev)
 717 {
 718         unsigned long flags;
 719 
 720         if (!dev)
 721                 return;
 722 
 723         spin_lock_irqsave(&dev->power.lock, flags);
 724         __pm_relax(dev->power.wakeup);
 725         spin_unlock_irqrestore(&dev->power.lock, flags);
 726 }
 727 EXPORT_SYMBOL_GPL(pm_relax);
 728 
 729 /**
 730  * pm_wakeup_timer_fn - Delayed finalization of a wakeup event.
 731  * @data: Address of the wakeup source object associated with the event source.
 732  *
 733  * Call wakeup_source_deactivate() for the wakeup source whose address is stored
 734  * in @data if it is currently active and its timer has not been canceled and
 735  * the expiration time of the timer is not in future.
 736  */
 737 static void pm_wakeup_timer_fn(struct timer_list *t)
 738 {
 739         struct wakeup_source *ws = from_timer(ws, t, timer);
 740         unsigned long flags;
 741 
 742         spin_lock_irqsave(&ws->lock, flags);
 743 
 744         if (ws->active && ws->timer_expires
 745             && time_after_eq(jiffies, ws->timer_expires)) {
 746                 wakeup_source_deactivate(ws);
 747                 ws->expire_count++;
 748         }
 749 
 750         spin_unlock_irqrestore(&ws->lock, flags);
 751 }
 752 
 753 /**
 754  * pm_wakeup_ws_event - Notify the PM core of a wakeup event.
 755  * @ws: Wakeup source object associated with the event source.
 756  * @msec: Anticipated event processing time (in milliseconds).
 757  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
 758  *
 759  * Notify the PM core of a wakeup event whose source is @ws that will take
 760  * approximately @msec milliseconds to be processed by the kernel.  If @ws is
 761  * not active, activate it.  If @msec is nonzero, set up the @ws' timer to
 762  * execute pm_wakeup_timer_fn() in future.
 763  *
 764  * It is safe to call this function from interrupt context.
 765  */
 766 void pm_wakeup_ws_event(struct wakeup_source *ws, unsigned int msec, bool hard)
 767 {
 768         unsigned long flags;
 769         unsigned long expires;
 770 
 771         if (!ws)
 772                 return;
 773 
 774         spin_lock_irqsave(&ws->lock, flags);
 775 
 776         wakeup_source_report_event(ws, hard);
 777 
 778         if (!msec) {
 779                 wakeup_source_deactivate(ws);
 780                 goto unlock;
 781         }
 782 
 783         expires = jiffies + msecs_to_jiffies(msec);
 784         if (!expires)
 785                 expires = 1;
 786 
 787         if (!ws->timer_expires || time_after(expires, ws->timer_expires)) {
 788                 mod_timer(&ws->timer, expires);
 789                 ws->timer_expires = expires;
 790         }
 791 
 792  unlock:
 793         spin_unlock_irqrestore(&ws->lock, flags);
 794 }
 795 EXPORT_SYMBOL_GPL(pm_wakeup_ws_event);
 796 
 797 /**
 798  * pm_wakeup_dev_event - Notify the PM core of a wakeup event.
 799  * @dev: Device the wakeup event is related to.
 800  * @msec: Anticipated event processing time (in milliseconds).
 801  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
 802  *
 803  * Call pm_wakeup_ws_event() for the @dev's wakeup source object.
 804  */
 805 void pm_wakeup_dev_event(struct device *dev, unsigned int msec, bool hard)
 806 {
 807         unsigned long flags;
 808 
 809         if (!dev)
 810                 return;
 811 
 812         spin_lock_irqsave(&dev->power.lock, flags);
 813         pm_wakeup_ws_event(dev->power.wakeup, msec, hard);
 814         spin_unlock_irqrestore(&dev->power.lock, flags);
 815 }
 816 EXPORT_SYMBOL_GPL(pm_wakeup_dev_event);
 817 
 818 void pm_print_active_wakeup_sources(void)
 819 {
 820         struct wakeup_source *ws;
 821         int srcuidx, active = 0;
 822         struct wakeup_source *last_activity_ws = NULL;
 823 
 824         srcuidx = srcu_read_lock(&wakeup_srcu);
 825         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 826                 if (ws->active) {
 827                         pm_pr_dbg("active wakeup source: %s\n", ws->name);
 828                         active = 1;
 829                 } else if (!active &&
 830                            (!last_activity_ws ||
 831                             ktime_to_ns(ws->last_time) >
 832                             ktime_to_ns(last_activity_ws->last_time))) {
 833                         last_activity_ws = ws;
 834                 }
 835         }
 836 
 837         if (!active && last_activity_ws)
 838                 pm_pr_dbg("last active wakeup source: %s\n",
 839                         last_activity_ws->name);
 840         srcu_read_unlock(&wakeup_srcu, srcuidx);
 841 }
 842 EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources);
 843 
 844 /**
 845  * pm_wakeup_pending - Check if power transition in progress should be aborted.
 846  *
 847  * Compare the current number of registered wakeup events with its preserved
 848  * value from the past and return true if new wakeup events have been registered
 849  * since the old value was stored.  Also return true if the current number of
 850  * wakeup events being processed is different from zero.
 851  */
 852 bool pm_wakeup_pending(void)
 853 {
 854         unsigned long flags;
 855         bool ret = false;
 856 
 857         raw_spin_lock_irqsave(&events_lock, flags);
 858         if (events_check_enabled) {
 859                 unsigned int cnt, inpr;
 860 
 861                 split_counters(&cnt, &inpr);
 862                 ret = (cnt != saved_count || inpr > 0);
 863                 events_check_enabled = !ret;
 864         }
 865         raw_spin_unlock_irqrestore(&events_lock, flags);
 866 
 867         if (ret) {
 868                 pm_pr_dbg("Wakeup pending, aborting suspend\n");
 869                 pm_print_active_wakeup_sources();
 870         }
 871 
 872         return ret || atomic_read(&pm_abort_suspend) > 0;
 873 }
 874 
 875 void pm_system_wakeup(void)
 876 {
 877         atomic_inc(&pm_abort_suspend);
 878         s2idle_wake();
 879 }
 880 EXPORT_SYMBOL_GPL(pm_system_wakeup);
 881 
 882 void pm_system_cancel_wakeup(void)
 883 {
 884         atomic_dec_if_positive(&pm_abort_suspend);
 885 }
 886 
 887 void pm_wakeup_clear(bool reset)
 888 {
 889         pm_wakeup_irq = 0;
 890         if (reset)
 891                 atomic_set(&pm_abort_suspend, 0);
 892 }
 893 
 894 void pm_system_irq_wakeup(unsigned int irq_number)
 895 {
 896         if (pm_wakeup_irq == 0) {
 897                 pm_wakeup_irq = irq_number;
 898                 pm_system_wakeup();
 899         }
 900 }
 901 
 902 /**
 903  * pm_get_wakeup_count - Read the number of registered wakeup events.
 904  * @count: Address to store the value at.
 905  * @block: Whether or not to block.
 906  *
 907  * Store the number of registered wakeup events at the address in @count.  If
 908  * @block is set, block until the current number of wakeup events being
 909  * processed is zero.
 910  *
 911  * Return 'false' if the current number of wakeup events being processed is
 912  * nonzero.  Otherwise return 'true'.
 913  */
 914 bool pm_get_wakeup_count(unsigned int *count, bool block)
 915 {
 916         unsigned int cnt, inpr;
 917 
 918         if (block) {
 919                 DEFINE_WAIT(wait);
 920 
 921                 for (;;) {
 922                         prepare_to_wait(&wakeup_count_wait_queue, &wait,
 923                                         TASK_INTERRUPTIBLE);
 924                         split_counters(&cnt, &inpr);
 925                         if (inpr == 0 || signal_pending(current))
 926                                 break;
 927                         pm_print_active_wakeup_sources();
 928                         schedule();
 929                 }
 930                 finish_wait(&wakeup_count_wait_queue, &wait);
 931         }
 932 
 933         split_counters(&cnt, &inpr);
 934         *count = cnt;
 935         return !inpr;
 936 }
 937 
 938 /**
 939  * pm_save_wakeup_count - Save the current number of registered wakeup events.
 940  * @count: Value to compare with the current number of registered wakeup events.
 941  *
 942  * If @count is equal to the current number of registered wakeup events and the
 943  * current number of wakeup events being processed is zero, store @count as the
 944  * old number of registered wakeup events for pm_check_wakeup_events(), enable
 945  * wakeup events detection and return 'true'.  Otherwise disable wakeup events
 946  * detection and return 'false'.
 947  */
 948 bool pm_save_wakeup_count(unsigned int count)
 949 {
 950         unsigned int cnt, inpr;
 951         unsigned long flags;
 952 
 953         events_check_enabled = false;
 954         raw_spin_lock_irqsave(&events_lock, flags);
 955         split_counters(&cnt, &inpr);
 956         if (cnt == count && inpr == 0) {
 957                 saved_count = count;
 958                 events_check_enabled = true;
 959         }
 960         raw_spin_unlock_irqrestore(&events_lock, flags);
 961         return events_check_enabled;
 962 }
 963 
 964 #ifdef CONFIG_PM_AUTOSLEEP
 965 /**
 966  * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources.
 967  * @enabled: Whether to set or to clear the autosleep_enabled flags.
 968  */
 969 void pm_wakep_autosleep_enabled(bool set)
 970 {
 971         struct wakeup_source *ws;
 972         ktime_t now = ktime_get();
 973         int srcuidx;
 974 
 975         srcuidx = srcu_read_lock(&wakeup_srcu);
 976         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 977                 spin_lock_irq(&ws->lock);
 978                 if (ws->autosleep_enabled != set) {
 979                         ws->autosleep_enabled = set;
 980                         if (ws->active) {
 981                                 if (set)
 982                                         ws->start_prevent_time = now;
 983                                 else
 984                                         update_prevent_sleep_time(ws, now);
 985                         }
 986                 }
 987                 spin_unlock_irq(&ws->lock);
 988         }
 989         srcu_read_unlock(&wakeup_srcu, srcuidx);
 990 }
 991 #endif /* CONFIG_PM_AUTOSLEEP */
 992 
 993 /**
 994  * print_wakeup_source_stats - Print wakeup source statistics information.
 995  * @m: seq_file to print the statistics into.
 996  * @ws: Wakeup source object to print the statistics for.
 997  */
 998 static int print_wakeup_source_stats(struct seq_file *m,
 999                                      struct wakeup_source *ws)
1000 {
1001         unsigned long flags;
1002         ktime_t total_time;
1003         ktime_t max_time;
1004         unsigned long active_count;
1005         ktime_t active_time;
1006         ktime_t prevent_sleep_time;
1007 
1008         spin_lock_irqsave(&ws->lock, flags);
1009 
1010         total_time = ws->total_time;
1011         max_time = ws->max_time;
1012         prevent_sleep_time = ws->prevent_sleep_time;
1013         active_count = ws->active_count;
1014         if (ws->active) {
1015                 ktime_t now = ktime_get();
1016 
1017                 active_time = ktime_sub(now, ws->last_time);
1018                 total_time = ktime_add(total_time, active_time);
1019                 if (active_time > max_time)
1020                         max_time = active_time;
1021 
1022                 if (ws->autosleep_enabled)
1023                         prevent_sleep_time = ktime_add(prevent_sleep_time,
1024                                 ktime_sub(now, ws->start_prevent_time));
1025         } else {
1026                 active_time = 0;
1027         }
1028 
1029         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",
1030                    ws->name, active_count, ws->event_count,
1031                    ws->wakeup_count, ws->expire_count,
1032                    ktime_to_ms(active_time), ktime_to_ms(total_time),
1033                    ktime_to_ms(max_time), ktime_to_ms(ws->last_time),
1034                    ktime_to_ms(prevent_sleep_time));
1035 
1036         spin_unlock_irqrestore(&ws->lock, flags);
1037 
1038         return 0;
1039 }
1040 
1041 static void *wakeup_sources_stats_seq_start(struct seq_file *m,
1042                                         loff_t *pos)
1043 {
1044         struct wakeup_source *ws;
1045         loff_t n = *pos;
1046         int *srcuidx = m->private;
1047 
1048         if (n == 0) {
1049                 seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t"
1050                         "expire_count\tactive_since\ttotal_time\tmax_time\t"
1051                         "last_change\tprevent_suspend_time\n");
1052         }
1053 
1054         *srcuidx = srcu_read_lock(&wakeup_srcu);
1055         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
1056                 if (n-- <= 0)
1057                         return ws;
1058         }
1059 
1060         return NULL;
1061 }
1062 
1063 static void *wakeup_sources_stats_seq_next(struct seq_file *m,
1064                                         void *v, loff_t *pos)
1065 {
1066         struct wakeup_source *ws = v;
1067         struct wakeup_source *next_ws = NULL;
1068 
1069         ++(*pos);
1070 
1071         list_for_each_entry_continue_rcu(ws, &wakeup_sources, entry) {
1072                 next_ws = ws;
1073                 break;
1074         }
1075 
1076         return next_ws;
1077 }
1078 
1079 static void wakeup_sources_stats_seq_stop(struct seq_file *m, void *v)
1080 {
1081         int *srcuidx = m->private;
1082 
1083         srcu_read_unlock(&wakeup_srcu, *srcuidx);
1084 }
1085 
1086 /**
1087  * wakeup_sources_stats_seq_show - Print wakeup sources statistics information.
1088  * @m: seq_file to print the statistics into.
1089  * @v: wakeup_source of each iteration
1090  */
1091 static int wakeup_sources_stats_seq_show(struct seq_file *m, void *v)
1092 {
1093         struct wakeup_source *ws = v;
1094 
1095         print_wakeup_source_stats(m, ws);
1096 
1097         return 0;
1098 }
1099 
1100 static const struct seq_operations wakeup_sources_stats_seq_ops = {
1101         .start = wakeup_sources_stats_seq_start,
1102         .next  = wakeup_sources_stats_seq_next,
1103         .stop  = wakeup_sources_stats_seq_stop,
1104         .show  = wakeup_sources_stats_seq_show,
1105 };
1106 
1107 static int wakeup_sources_stats_open(struct inode *inode, struct file *file)
1108 {
1109         return seq_open_private(file, &wakeup_sources_stats_seq_ops, sizeof(int));
1110 }
1111 
1112 static const struct file_operations wakeup_sources_stats_fops = {
1113         .owner = THIS_MODULE,
1114         .open = wakeup_sources_stats_open,
1115         .read = seq_read,
1116         .llseek = seq_lseek,
1117         .release = seq_release_private,
1118 };
1119 
1120 static int __init wakeup_sources_debugfs_init(void)
1121 {
1122         debugfs_create_file("wakeup_sources", S_IRUGO, NULL, NULL,
1123                             &wakeup_sources_stats_fops);
1124         return 0;
1125 }
1126 
1127 postcore_initcall(wakeup_sources_debugfs_init);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/base/power/wakeup.c

DEFINITIONS
