drivers/base/power/domain.c

   1 /*
   2  * drivers/base/power/domain.c - Common code related to device power domains.
   3  *
   4  * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
   5  *
   6  * This file is released under the GPLv2.
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/kernel.h>
  11 #include <linux/io.h>
  12 #include <linux/pm_runtime.h>
  13 #include <linux/pm_domain.h>
  14 #include <linux/pm_qos.h>
  15 #include <linux/slab.h>
  16 #include <linux/err.h>
  17 #include <linux/sched.h>
  18 #include <linux/suspend.h>
  19 #include <linux/export.h>
  20
  21 #define GENPD_DEV_CALLBACK(genpd, type, callback, dev)          \
  22 ({                                                              \
  23         type (*__routine)(struct device *__d);                  \
  24         type __ret = (type)0;                                   \
  25                                                                 \
  26         __routine = genpd->dev_ops.callback;                    \
  27         if (__routine) {                                        \
  28                 __ret = __routine(dev);                         \
  29         } else {                                                \
  30                 __routine = dev_gpd_data(dev)->ops.callback;    \
  31                 if (__routine)                                  \
  32                         __ret = __routine(dev);                 \
  33         }                                                       \
  34         __ret;                                                  \
  35 })
  36
  37 #define GENPD_DEV_TIMED_CALLBACK(genpd, type, callback, dev, field, name)       \
  38 ({                                                                              \
  39         ktime_t __start = ktime_get();                                          \
  40         type __retval = GENPD_DEV_CALLBACK(genpd, type, callback, dev);         \
  41         s64 __elapsed = ktime_to_ns(ktime_sub(ktime_get(), __start));           \
  42         struct gpd_timing_data *__td = &dev_gpd_data(dev)->td;                  \
  43         if (!__retval && __elapsed > __td->field) {                             \
  44                 __td->field = __elapsed;                                        \
  45                 dev_warn(dev, name " latency exceeded, new value %lld ns\n",    \
  46                         __elapsed);                                             \
  47                 genpd->max_off_time_changed = true;                             \
  48                 __td->constraint_changed = true;                                \
  49         }                                                                       \
  50         __retval;                                                               \
  51 })
  52
  53 static LIST_HEAD(gpd_list);
  54 static DEFINE_MUTEX(gpd_list_lock);
  55
  56 static struct generic_pm_domain *pm_genpd_lookup_name(const char *domain_name)
  57 {
  58         struct generic_pm_domain *genpd = NULL, *gpd;
  59
  60         if (IS_ERR_OR_NULL(domain_name))
  61                 return NULL;
  62
  63         mutex_lock(&gpd_list_lock);
  64         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
  65                 if (!strcmp(gpd->name, domain_name)) {
  66                         genpd = gpd;
  67                         break;
  68                 }
  69         }
  70         mutex_unlock(&gpd_list_lock);
  71         return genpd;
  72 }
  73
  74 #ifdef CONFIG_PM
  75
  76 struct generic_pm_domain *dev_to_genpd(struct device *dev)
  77 {
  78         if (IS_ERR_OR_NULL(dev->pm_domain))
  79                 return ERR_PTR(-EINVAL);
  80
  81         return pd_to_genpd(dev->pm_domain);
  82 }
  83
  84 static int genpd_stop_dev(struct generic_pm_domain *genpd, struct device *dev)
  85 {
  86         return GENPD_DEV_TIMED_CALLBACK(genpd, int, stop, dev,
  87                                         stop_latency_ns, "stop");
  88 }
  89
  90 static int genpd_start_dev(struct generic_pm_domain *genpd, struct device *dev)
  91 {
  92         return GENPD_DEV_TIMED_CALLBACK(genpd, int, start, dev,
  93                                         start_latency_ns, "start");
  94 }
  95
  96 static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd)
  97 {
  98         bool ret = false;
  99
 100         if (!WARN_ON(atomic_read(&genpd->sd_count) == 0))
 101                 ret = !!atomic_dec_and_test(&genpd->sd_count);
 102
 103         return ret;
 104 }
 105
 106 static void genpd_sd_counter_inc(struct generic_pm_domain *genpd)
 107 {
 108         atomic_inc(&genpd->sd_count);
 109         smp_mb__after_atomic_inc();
 110 }
 111
 112 static void genpd_acquire_lock(struct generic_pm_domain *genpd)
 113 {
 114         DEFINE_WAIT(wait);
 115
 116         mutex_lock(&genpd->lock);
 117         /*
 118          * Wait for the domain to transition into either the active,
 119          * or the power off state.
 120          */
 121         for (;;) {
 122                 prepare_to_wait(&genpd->status_wait_queue, &wait,
 123                                 TASK_UNINTERRUPTIBLE);
 124                 if (genpd->status == GPD_STATE_ACTIVE
 125                     || genpd->status == GPD_STATE_POWER_OFF)
 126                         break;
 127                 mutex_unlock(&genpd->lock);
 128
 129                 schedule();
 130
 131                 mutex_lock(&genpd->lock);
 132         }
 133         finish_wait(&genpd->status_wait_queue, &wait);
 134 }
 135
 136 static void genpd_release_lock(struct generic_pm_domain *genpd)
 137 {
 138         mutex_unlock(&genpd->lock);
 139 }
 140
 141 static void genpd_set_active(struct generic_pm_domain *genpd)
 142 {
 143         if (genpd->resume_count == 0)
 144                 genpd->status = GPD_STATE_ACTIVE;
 145 }
 146
 147 static void genpd_recalc_cpu_exit_latency(struct generic_pm_domain *genpd)
 148 {
 149         s64 usecs64;
 150
 151         if (!genpd->cpu_data)
 152                 return;
 153
 154         usecs64 = genpd->power_on_latency_ns;
 155         do_div(usecs64, NSEC_PER_USEC);
 156         usecs64 += genpd->cpu_data->saved_exit_latency;
 157         genpd->cpu_data->idle_state->exit_latency = usecs64;
 158 }
 159
 160 /**
 161  * __pm_genpd_poweron - Restore power to a given PM domain and its masters.
 162  * @genpd: PM domain to power up.
 163  *
 164  * Restore power to @genpd and all of its masters so that it is possible to
 165  * resume a device belonging to it.
 166  */
 167 static int __pm_genpd_poweron(struct generic_pm_domain *genpd)
 168         __releases(&genpd->lock) __acquires(&genpd->lock)
 169 {
 170         struct gpd_link *link;
 171         DEFINE_WAIT(wait);
 172         int ret = 0;
 173
 174         /* If the domain's master is being waited for, we have to wait too. */
 175         for (;;) {
 176                 prepare_to_wait(&genpd->status_wait_queue, &wait,
 177                                 TASK_UNINTERRUPTIBLE);
 178                 if (genpd->status != GPD_STATE_WAIT_MASTER)
 179                         break;
 180                 mutex_unlock(&genpd->lock);
 181
 182                 schedule();
 183
 184                 mutex_lock(&genpd->lock);
 185         }
 186         finish_wait(&genpd->status_wait_queue, &wait);
 187
 188         if (genpd->status == GPD_STATE_ACTIVE
 189             || (genpd->prepared_count > 0 && genpd->suspend_power_off))
 190                 return 0;
 191
 192         if (genpd->status != GPD_STATE_POWER_OFF) {
 193                 genpd_set_active(genpd);
 194                 return 0;
 195         }
 196
 197         if (genpd->cpu_data) {
 198                 cpuidle_pause_and_lock();
 199                 genpd->cpu_data->idle_state->disabled = true;
 200                 cpuidle_resume_and_unlock();
 201                 goto out;
 202         }
 203
 204         /*
 205          * The list is guaranteed not to change while the loop below is being
 206          * executed, unless one of the masters' .power_on() callbacks fiddles
 207          * with it.
 208          */
 209         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 210                 genpd_sd_counter_inc(link->master);
 211                 genpd->status = GPD_STATE_WAIT_MASTER;
 212
 213                 mutex_unlock(&genpd->lock);
 214
 215                 ret = pm_genpd_poweron(link->master);
 216
 217                 mutex_lock(&genpd->lock);
 218
 219                 /*
 220                  * The "wait for parent" status is guaranteed not to change
 221                  * while the master is powering on.
 222                  */
 223                 genpd->status = GPD_STATE_POWER_OFF;
 224                 wake_up_all(&genpd->status_wait_queue);
 225                 if (ret) {
 226                         genpd_sd_counter_dec(link->master);
 227                         goto err;
 228                 }
 229         }
 230
 231         if (genpd->power_on) {
 232                 ktime_t time_start = ktime_get();
 233                 s64 elapsed_ns;
 234
 235                 ret = genpd->power_on(genpd);
 236                 if (ret)
 237                         goto err;
 238
 239                 elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
 240                 if (elapsed_ns > genpd->power_on_latency_ns) {
 241                         genpd->power_on_latency_ns = elapsed_ns;
 242                         genpd->max_off_time_changed = true;
 243                         genpd_recalc_cpu_exit_latency(genpd);
 244                         if (genpd->name)
 245                                 pr_warning("%s: Power-on latency exceeded, "
 246                                         "new value %lld ns\n", genpd->name,
 247                                         elapsed_ns);
 248                 }
 249         }
 250
 251  out:
 252         genpd_set_active(genpd);
 253
 254         return 0;
 255
 256  err:
 257         list_for_each_entry_continue_reverse(link, &genpd->slave_links, slave_node)
 258                 genpd_sd_counter_dec(link->master);
 259
 260         return ret;
 261 }
 262
 263 /**
 264  * pm_genpd_poweron - Restore power to a given PM domain and its masters.
 265  * @genpd: PM domain to power up.
 266  */
 267 int pm_genpd_poweron(struct generic_pm_domain *genpd)
 268 {
 269         int ret;
 270
 271         mutex_lock(&genpd->lock);
 272         ret = __pm_genpd_poweron(genpd);
 273         mutex_unlock(&genpd->lock);
 274         return ret;
 275 }
 276
 277 /**
 278  * pm_genpd_name_poweron - Restore power to a given PM domain and its masters.
 279  * @domain_name: Name of the PM domain to power up.
 280  */
 281 int pm_genpd_name_poweron(const char *domain_name)
 282 {
 283         struct generic_pm_domain *genpd;
 284
 285         genpd = pm_genpd_lookup_name(domain_name);
 286         return genpd ? pm_genpd_poweron(genpd) : -EINVAL;
 287 }
 288
 289 #endif /* CONFIG_PM */
 290
 291 #ifdef CONFIG_PM_RUNTIME
 292
 293 static int genpd_start_dev_no_timing(struct generic_pm_domain *genpd,
 294                                      struct device *dev)
 295 {
 296         return GENPD_DEV_CALLBACK(genpd, int, start, dev);
 297 }
 298
 299 static int genpd_save_dev(struct generic_pm_domain *genpd, struct device *dev)
 300 {
 301         return GENPD_DEV_TIMED_CALLBACK(genpd, int, save_state, dev,
 302                                         save_state_latency_ns, "state save");
 303 }
 304
 305 static int genpd_restore_dev(struct generic_pm_domain *genpd, struct device *dev)
 306 {
 307         return GENPD_DEV_TIMED_CALLBACK(genpd, int, restore_state, dev,
 308                                         restore_state_latency_ns,
 309                                         "state restore");
 310 }
 311
 312 static int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
 313                                      unsigned long val, void *ptr)
 314 {
 315         struct generic_pm_domain_data *gpd_data;
 316         struct device *dev;
 317
 318         gpd_data = container_of(nb, struct generic_pm_domain_data, nb);
 319
 320         mutex_lock(&gpd_data->lock);
 321         dev = gpd_data->base.dev;
 322         if (!dev) {
 323                 mutex_unlock(&gpd_data->lock);
 324                 return NOTIFY_DONE;
 325         }
 326         mutex_unlock(&gpd_data->lock);
 327
 328         for (;;) {
 329                 struct generic_pm_domain *genpd;
 330                 struct pm_domain_data *pdd;
 331
 332                 spin_lock_irq(&dev->power.lock);
 333
 334                 pdd = dev->power.subsys_data ?
 335                                 dev->power.subsys_data->domain_data : NULL;
 336                 if (pdd && pdd->dev) {
 337                         to_gpd_data(pdd)->td.constraint_changed = true;
 338                         genpd = dev_to_genpd(dev);
 339                 } else {
 340                         genpd = ERR_PTR(-ENODATA);
 341                 }
 342
 343                 spin_unlock_irq(&dev->power.lock);
 344
 345                 if (!IS_ERR(genpd)) {
 346                         mutex_lock(&genpd->lock);
 347                         genpd->max_off_time_changed = true;
 348                         mutex_unlock(&genpd->lock);
 349                 }
 350
 351                 dev = dev->parent;
 352                 if (!dev || dev->power.ignore_children)
 353                         break;
 354         }
 355
 356         return NOTIFY_DONE;
 357 }
 358
 359 /**
 360  * __pm_genpd_save_device - Save the pre-suspend state of a device.
 361  * @pdd: Domain data of the device to save the state of.
 362  * @genpd: PM domain the device belongs to.
 363  */
 364 static int __pm_genpd_save_device(struct pm_domain_data *pdd,
 365                                   struct generic_pm_domain *genpd)
 366         __releases(&genpd->lock) __acquires(&genpd->lock)
 367 {
 368         struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
 369         struct device *dev = pdd->dev;
 370         int ret = 0;
 371
 372         if (gpd_data->need_restore)
 373                 return 0;
 374
 375         mutex_unlock(&genpd->lock);
 376
 377         genpd_start_dev(genpd, dev);
 378         ret = genpd_save_dev(genpd, dev);
 379         genpd_stop_dev(genpd, dev);
 380
 381         mutex_lock(&genpd->lock);
 382
 383         if (!ret)
 384                 gpd_data->need_restore = true;
 385
 386         return ret;
 387 }
 388
 389 /**
 390  * __pm_genpd_restore_device - Restore the pre-suspend state of a device.
 391  * @pdd: Domain data of the device to restore the state of.
 392  * @genpd: PM domain the device belongs to.
 393  */
 394 static void __pm_genpd_restore_device(struct pm_domain_data *pdd,
 395                                       struct generic_pm_domain *genpd)
 396         __releases(&genpd->lock) __acquires(&genpd->lock)
 397 {
 398         struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
 399         struct device *dev = pdd->dev;
 400         bool need_restore = gpd_data->need_restore;
 401
 402         gpd_data->need_restore = false;
 403         mutex_unlock(&genpd->lock);
 404
 405         genpd_start_dev(genpd, dev);
 406         if (need_restore)
 407                 genpd_restore_dev(genpd, dev);
 408
 409         mutex_lock(&genpd->lock);
 410 }
 411
 412 /**
 413  * genpd_abort_poweroff - Check if a PM domain power off should be aborted.
 414  * @genpd: PM domain to check.
 415  *
 416  * Return true if a PM domain's status changed to GPD_STATE_ACTIVE during
 417  * a "power off" operation, which means that a "power on" has occured in the
 418  * meantime, or if its resume_count field is different from zero, which means
 419  * that one of its devices has been resumed in the meantime.
 420  */
 421 static bool genpd_abort_poweroff(struct generic_pm_domain *genpd)
 422 {
 423         return genpd->status == GPD_STATE_WAIT_MASTER
 424                 || genpd->status == GPD_STATE_ACTIVE || genpd->resume_count > 0;
 425 }
 426
 427 /**
 428  * genpd_queue_power_off_work - Queue up the execution of pm_genpd_poweroff().
 429  * @genpd: PM domait to power off.
 430  *
 431  * Queue up the execution of pm_genpd_poweroff() unless it's already been done
 432  * before.
 433  */
 434 void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
 435 {
 436         if (!work_pending(&genpd->power_off_work))
 437                 queue_work(pm_wq, &genpd->power_off_work);
 438 }
 439
 440 /**
 441  * pm_genpd_poweroff - Remove power from a given PM domain.
 442  * @genpd: PM domain to power down.
 443  *
 444  * If all of the @genpd's devices have been suspended and all of its subdomains
 445  * have been powered down, run the runtime suspend callbacks provided by all of
 446  * the @genpd's devices' drivers and remove power from @genpd.
 447  */
 448 static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
 449         __releases(&genpd->lock) __acquires(&genpd->lock)
 450 {
 451         struct pm_domain_data *pdd;
 452         struct gpd_link *link;
 453         unsigned int not_suspended;
 454         int ret = 0;
 455
 456  start:
 457         /*
 458          * Do not try to power off the domain in the following situations:
 459          * (1) The domain is already in the "power off" state.
 460          * (2) The domain is waiting for its master to power up.
 461          * (3) One of the domain's devices is being resumed right now.
 462          * (4) System suspend is in progress.
 463          */
 464         if (genpd->status == GPD_STATE_POWER_OFF
 465             || genpd->status == GPD_STATE_WAIT_MASTER
 466             || genpd->resume_count > 0 || genpd->prepared_count > 0)
 467                 return 0;
 468
 469         if (atomic_read(&genpd->sd_count) > 0)
 470                 return -EBUSY;
 471
 472         not_suspended = 0;
 473         list_for_each_entry(pdd, &genpd->dev_list, list_node)
 474                 if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev)
 475                     || pdd->dev->power.irq_safe))
 476                         not_suspended++;
 477
 478         if (not_suspended > genpd->in_progress)
 479                 return -EBUSY;
 480
 481         if (genpd->poweroff_task) {
 482                 /*
 483                  * Another instance of pm_genpd_poweroff() is executing
 484                  * callbacks, so tell it to start over and return.
 485                  */
 486                 genpd->status = GPD_STATE_REPEAT;
 487                 return 0;
 488         }
 489
 490         if (genpd->gov && genpd->gov->power_down_ok) {
 491                 if (!genpd->gov->power_down_ok(&genpd->domain))
 492                         return -EAGAIN;
 493         }
 494
 495         genpd->status = GPD_STATE_BUSY;
 496         genpd->poweroff_task = current;
 497
 498         list_for_each_entry_reverse(pdd, &genpd->dev_list, list_node) {
 499                 ret = atomic_read(&genpd->sd_count) == 0 ?
 500                         __pm_genpd_save_device(pdd, genpd) : -EBUSY;
 501
 502                 if (genpd_abort_poweroff(genpd))
 503                         goto out;
 504
 505                 if (ret) {
 506                         genpd_set_active(genpd);
 507                         goto out;
 508                 }
 509
 510                 if (genpd->status == GPD_STATE_REPEAT) {
 511                         genpd->poweroff_task = NULL;
 512                         goto start;
 513                 }
 514         }
 515
 516         if (genpd->cpu_data) {
 517                 /*
 518                  * If cpu_data is set, cpuidle should turn the domain off when
 519                  * the CPU in it is idle.  In that case we don't decrement the
 520                  * subdomain counts of the master domains, so that power is not
 521                  * removed from the current domain prematurely as a result of
 522                  * cutting off the masters' power.
 523                  */
 524                 genpd->status = GPD_STATE_POWER_OFF;
 525                 cpuidle_pause_and_lock();
 526                 genpd->cpu_data->idle_state->disabled = false;
 527                 cpuidle_resume_and_unlock();
 528                 goto out;
 529         }
 530
 531         if (genpd->power_off) {
 532                 ktime_t time_start;
 533                 s64 elapsed_ns;
 534
 535                 if (atomic_read(&genpd->sd_count) > 0) {
 536                         ret = -EBUSY;
 537                         goto out;
 538                 }
 539
 540                 time_start = ktime_get();
 541
 542                 /*
 543                  * If sd_count > 0 at this point, one of the subdomains hasn't
 544                  * managed to call pm_genpd_poweron() for the master yet after
 545                  * incrementing it.  In that case pm_genpd_poweron() will wait
 546                  * for us to drop the lock, so we can call .power_off() and let
 547                  * the pm_genpd_poweron() restore power for us (this shouldn't
 548                  * happen very often).
 549                  */
 550                 ret = genpd->power_off(genpd);
 551                 if (ret == -EBUSY) {
 552                         genpd_set_active(genpd);
 553                         goto out;
 554                 }
 555
 556                 elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
 557                 if (elapsed_ns > genpd->power_off_latency_ns) {
 558                         genpd->power_off_latency_ns = elapsed_ns;
 559                         genpd->max_off_time_changed = true;
 560                         if (genpd->name)
 561                                 pr_warning("%s: Power-off latency exceeded, "
 562                                         "new value %lld ns\n", genpd->name,
 563                                         elapsed_ns);
 564                 }
 565         }
 566
 567         genpd->status = GPD_STATE_POWER_OFF;
 568
 569         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 570                 genpd_sd_counter_dec(link->master);
 571                 genpd_queue_power_off_work(link->master);
 572         }
 573
 574  out:
 575         genpd->poweroff_task = NULL;
 576         wake_up_all(&genpd->status_wait_queue);
 577         return ret;
 578 }
 579
 580 /**
 581  * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0.
 582  * @work: Work structure used for scheduling the execution of this function.
 583  */
 584 static void genpd_power_off_work_fn(struct work_struct *work)
 585 {
 586         struct generic_pm_domain *genpd;
 587
 588         genpd = container_of(work, struct generic_pm_domain, power_off_work);
 589
 590         genpd_acquire_lock(genpd);
 591         pm_genpd_poweroff(genpd);
 592         genpd_release_lock(genpd);
 593 }
 594
 595 /**
 596  * pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain.
 597  * @dev: Device to suspend.
 598  *
 599  * Carry out a runtime suspend of a device under the assumption that its
 600  * pm_domain field points to the domain member of an object of type
 601  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 602  */
 603 static int pm_genpd_runtime_suspend(struct device *dev)
 604 {
 605         struct generic_pm_domain *genpd;
 606         bool (*stop_ok)(struct device *__dev);
 607         int ret;
 608
 609         dev_dbg(dev, "%s()\n", __func__);
 610
 611         genpd = dev_to_genpd(dev);
 612         if (IS_ERR(genpd))
 613                 return -EINVAL;
 614
 615         might_sleep_if(!genpd->dev_irq_safe);
 616
 617         stop_ok = genpd->gov ? genpd->gov->stop_ok : NULL;
 618         if (stop_ok && !stop_ok(dev))
 619                 return -EBUSY;
 620
 621         ret = genpd_stop_dev(genpd, dev);
 622         if (ret)
 623                 return ret;
 624
 625         /*
 626          * If power.irq_safe is set, this routine will be run with interrupts
 627          * off, so it can't use mutexes.
 628          */
 629         if (dev->power.irq_safe)
 630                 return 0;
 631
 632         mutex_lock(&genpd->lock);
 633         genpd->in_progress++;
 634         pm_genpd_poweroff(genpd);
 635         genpd->in_progress--;
 636         mutex_unlock(&genpd->lock);
 637
 638         return 0;
 639 }
 640
 641 /**
 642  * pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain.
 643  * @dev: Device to resume.
 644  *
 645  * Carry out a runtime resume of a device under the assumption that its
 646  * pm_domain field points to the domain member of an object of type
 647  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 648  */
 649 static int pm_genpd_runtime_resume(struct device *dev)
 650 {
 651         struct generic_pm_domain *genpd;
 652         DEFINE_WAIT(wait);
 653         int ret;
 654
 655         dev_dbg(dev, "%s()\n", __func__);
 656
 657         genpd = dev_to_genpd(dev);
 658         if (IS_ERR(genpd))
 659                 return -EINVAL;
 660
 661         might_sleep_if(!genpd->dev_irq_safe);
 662
 663         /* If power.irq_safe, the PM domain is never powered off. */
 664         if (dev->power.irq_safe)
 665                 return genpd_start_dev_no_timing(genpd, dev);
 666
 667         mutex_lock(&genpd->lock);
 668         ret = __pm_genpd_poweron(genpd);
 669         if (ret) {
 670                 mutex_unlock(&genpd->lock);
 671                 return ret;
 672         }
 673         genpd->status = GPD_STATE_BUSY;
 674         genpd->resume_count++;
 675         for (;;) {
 676                 prepare_to_wait(&genpd->status_wait_queue, &wait,
 677                                 TASK_UNINTERRUPTIBLE);
 678                 /*
 679                  * If current is the powering off task, we have been called
 680                  * reentrantly from one of the device callbacks, so we should
 681                  * not wait.
 682                  */
 683                 if (!genpd->poweroff_task || genpd->poweroff_task == current)
 684                         break;
 685                 mutex_unlock(&genpd->lock);
 686
 687                 schedule();
 688
 689                 mutex_lock(&genpd->lock);
 690         }
 691         finish_wait(&genpd->status_wait_queue, &wait);
 692         __pm_genpd_restore_device(dev->power.subsys_data->domain_data, genpd);
 693         genpd->resume_count--;
 694         genpd_set_active(genpd);
 695         wake_up_all(&genpd->status_wait_queue);
 696         mutex_unlock(&genpd->lock);
 697
 698         return 0;
 699 }
 700
 701 /**
 702  * pm_genpd_poweroff_unused - Power off all PM domains with no devices in use.
 703  */
 704 void pm_genpd_poweroff_unused(void)
 705 {
 706         struct generic_pm_domain *genpd;
 707
 708         mutex_lock(&gpd_list_lock);
 709
 710         list_for_each_entry(genpd, &gpd_list, gpd_list_node)
 711                 genpd_queue_power_off_work(genpd);
 712
 713         mutex_unlock(&gpd_list_lock);
 714 }
 715
 716 #else
 717
 718 static inline int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
 719                                             unsigned long val, void *ptr)
 720 {
 721         return NOTIFY_DONE;
 722 }
 723
 724 static inline void genpd_power_off_work_fn(struct work_struct *work) {}
 725
 726 #define pm_genpd_runtime_suspend        NULL
 727 #define pm_genpd_runtime_resume         NULL
 728
 729 #endif /* CONFIG_PM_RUNTIME */
 730
 731 #ifdef CONFIG_PM_SLEEP
 732
 733 /**
 734  * pm_genpd_present - Check if the given PM domain has been initialized.
 735  * @genpd: PM domain to check.
 736  */
 737 static bool pm_genpd_present(struct generic_pm_domain *genpd)
 738 {
 739         struct generic_pm_domain *gpd;
 740
 741         if (IS_ERR_OR_NULL(genpd))
 742                 return false;
 743
 744         list_for_each_entry(gpd, &gpd_list, gpd_list_node)
 745                 if (gpd == genpd)
 746                         return true;
 747
 748         return false;
 749 }
 750
 751 static bool genpd_dev_active_wakeup(struct generic_pm_domain *genpd,
 752                                     struct device *dev)
 753 {
 754         return GENPD_DEV_CALLBACK(genpd, bool, active_wakeup, dev);
 755 }
 756
 757 static int genpd_suspend_dev(struct generic_pm_domain *genpd, struct device *dev)
 758 {
 759         return GENPD_DEV_CALLBACK(genpd, int, suspend, dev);
 760 }
 761
 762 static int genpd_suspend_late(struct generic_pm_domain *genpd, struct device *dev)
 763 {
 764         return GENPD_DEV_CALLBACK(genpd, int, suspend_late, dev);
 765 }
 766
 767 static int genpd_resume_early(struct generic_pm_domain *genpd, struct device *dev)
 768 {
 769         return GENPD_DEV_CALLBACK(genpd, int, resume_early, dev);
 770 }
 771
 772 static int genpd_resume_dev(struct generic_pm_domain *genpd, struct device *dev)
 773 {
 774         return GENPD_DEV_CALLBACK(genpd, int, resume, dev);
 775 }
 776
 777 static int genpd_freeze_dev(struct generic_pm_domain *genpd, struct device *dev)
 778 {
 779         return GENPD_DEV_CALLBACK(genpd, int, freeze, dev);
 780 }
 781
 782 static int genpd_freeze_late(struct generic_pm_domain *genpd, struct device *dev)
 783 {
 784         return GENPD_DEV_CALLBACK(genpd, int, freeze_late, dev);
 785 }
 786
 787 static int genpd_thaw_early(struct generic_pm_domain *genpd, struct device *dev)
 788 {
 789         return GENPD_DEV_CALLBACK(genpd, int, thaw_early, dev);
 790 }
 791
 792 static int genpd_thaw_dev(struct generic_pm_domain *genpd, struct device *dev)
 793 {
 794         return GENPD_DEV_CALLBACK(genpd, int, thaw, dev);
 795 }
 796
 797 /**
 798  * pm_genpd_sync_poweroff - Synchronously power off a PM domain and its masters.
 799  * @genpd: PM domain to power off, if possible.
 800  *
 801  * Check if the given PM domain can be powered off (during system suspend or
 802  * hibernation) and do that if so.  Also, in that case propagate to its masters.
 803  *
 804  * This function is only called in "noirq" and "syscore" stages of system power
 805  * transitions, so it need not acquire locks (all of the "noirq" callbacks are
 806  * executed sequentially, so it is guaranteed that it will never run twice in
 807  * parallel).
 808  */
 809 static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd)
 810 {
 811         struct gpd_link *link;
 812
 813         if (genpd->status == GPD_STATE_POWER_OFF)
 814                 return;
 815
 816         if (genpd->suspended_count != genpd->device_count
 817             || atomic_read(&genpd->sd_count) > 0)
 818                 return;
 819
 820         if (genpd->power_off)
 821                 genpd->power_off(genpd);
 822
 823         genpd->status = GPD_STATE_POWER_OFF;
 824
 825         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 826                 genpd_sd_counter_dec(link->master);
 827                 pm_genpd_sync_poweroff(link->master);
 828         }
 829 }
 830
 831 /**
 832  * pm_genpd_sync_poweron - Synchronously power on a PM domain and its masters.
 833  * @genpd: PM domain to power on.
 834  *
 835  * This function is only called in "noirq" and "syscore" stages of system power
 836  * transitions, so it need not acquire locks (all of the "noirq" callbacks are
 837  * executed sequentially, so it is guaranteed that it will never run twice in
 838  * parallel).
 839  */
 840 static void pm_genpd_sync_poweron(struct generic_pm_domain *genpd)
 841 {
 842         struct gpd_link *link;
 843
 844         if (genpd->status != GPD_STATE_POWER_OFF)
 845                 return;
 846
 847         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 848                 pm_genpd_sync_poweron(link->master);
 849                 genpd_sd_counter_inc(link->master);
 850         }
 851
 852         if (genpd->power_on)
 853                 genpd->power_on(genpd);
 854
 855         genpd->status = GPD_STATE_ACTIVE;
 856 }
 857
 858 /**
 859  * resume_needed - Check whether to resume a device before system suspend.
 860  * @dev: Device to check.
 861  * @genpd: PM domain the device belongs to.
 862  *
 863  * There are two cases in which a device that can wake up the system from sleep
 864  * states should be resumed by pm_genpd_prepare(): (1) if the device is enabled
 865  * to wake up the system and it has to remain active for this purpose while the
 866  * system is in the sleep state and (2) if the device is not enabled to wake up
 867  * the system from sleep states and it generally doesn't generate wakeup signals
 868  * by itself (those signals are generated on its behalf by other parts of the
 869  * system).  In the latter case it may be necessary to reconfigure the device's
 870  * wakeup settings during system suspend, because it may have been set up to
 871  * signal remote wakeup from the system's working state as needed by runtime PM.
 872  * Return 'true' in either of the above cases.
 873  */
 874 static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd)
 875 {
 876         bool active_wakeup;
 877
 878         if (!device_can_wakeup(dev))
 879                 return false;
 880
 881         active_wakeup = genpd_dev_active_wakeup(genpd, dev);
 882         return device_may_wakeup(dev) ? active_wakeup : !active_wakeup;
 883 }
 884
 885 /**
 886  * pm_genpd_prepare - Start power transition of a device in a PM domain.
 887  * @dev: Device to start the transition of.
 888  *
 889  * Start a power transition of a device (during a system-wide power transition)
 890  * under the assumption that its pm_domain field points to the domain member of
 891  * an object of type struct generic_pm_domain representing a PM domain
 892  * consisting of I/O devices.
 893  */
 894 static int pm_genpd_prepare(struct device *dev)
 895 {
 896         struct generic_pm_domain *genpd;
 897         int ret;
 898
 899         dev_dbg(dev, "%s()\n", __func__);
 900
 901         genpd = dev_to_genpd(dev);
 902         if (IS_ERR(genpd))
 903                 return -EINVAL;
 904
 905         /*
 906          * If a wakeup request is pending for the device, it should be woken up
 907          * at this point and a system wakeup event should be reported if it's
 908          * set up to wake up the system from sleep states.
 909          */
 910         pm_runtime_get_noresume(dev);
 911         if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
 912                 pm_wakeup_event(dev, 0);
 913
 914         if (pm_wakeup_pending()) {
 915                 pm_runtime_put_sync(dev);
 916                 return -EBUSY;
 917         }
 918
 919         if (resume_needed(dev, genpd))
 920                 pm_runtime_resume(dev);
 921
 922         genpd_acquire_lock(genpd);
 923
 924         if (genpd->prepared_count++ == 0) {
 925                 genpd->suspended_count = 0;
 926                 genpd->suspend_power_off = genpd->status == GPD_STATE_POWER_OFF;
 927         }
 928
 929         genpd_release_lock(genpd);
 930
 931         if (genpd->suspend_power_off) {
 932                 pm_runtime_put_noidle(dev);
 933                 return 0;
 934         }
 935
 936         /*
 937          * The PM domain must be in the GPD_STATE_ACTIVE state at this point,
 938          * so pm_genpd_poweron() will return immediately, but if the device
 939          * is suspended (e.g. it's been stopped by genpd_stop_dev()), we need
 940          * to make it operational.
 941          */
 942         pm_runtime_resume(dev);
 943         __pm_runtime_disable(dev, false);
 944
 945         ret = pm_generic_prepare(dev);
 946         if (ret) {
 947                 mutex_lock(&genpd->lock);
 948
 949                 if (--genpd->prepared_count == 0)
 950                         genpd->suspend_power_off = false;
 951
 952                 mutex_unlock(&genpd->lock);
 953                 pm_runtime_enable(dev);
 954         }
 955
 956         pm_runtime_put_sync(dev);
 957         return ret;
 958 }
 959
 960 /**
 961  * pm_genpd_suspend - Suspend a device belonging to an I/O PM domain.
 962  * @dev: Device to suspend.
 963  *
 964  * Suspend a device under the assumption that its pm_domain field points to the
 965  * domain member of an object of type struct generic_pm_domain representing
 966  * a PM domain consisting of I/O devices.
 967  */
 968 static int pm_genpd_suspend(struct device *dev)
 969 {
 970         struct generic_pm_domain *genpd;
 971
 972         dev_dbg(dev, "%s()\n", __func__);
 973
 974         genpd = dev_to_genpd(dev);
 975         if (IS_ERR(genpd))
 976                 return -EINVAL;
 977
 978         return genpd->suspend_power_off ? 0 : genpd_suspend_dev(genpd, dev);
 979 }
 980
 981 /**
 982  * pm_genpd_suspend_late - Late suspend of a device from an I/O PM domain.
 983  * @dev: Device to suspend.
 984  *
 985  * Carry out a late suspend of a device under the assumption that its
 986  * pm_domain field points to the domain member of an object of type
 987  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 988  */
 989 static int pm_genpd_suspend_late(struct device *dev)
 990 {
 991         struct generic_pm_domain *genpd;
 992
 993         dev_dbg(dev, "%s()\n", __func__);
 994
 995         genpd = dev_to_genpd(dev);
 996         if (IS_ERR(genpd))
 997                 return -EINVAL;
 998
 999         return genpd->suspend_power_off ? 0 : genpd_suspend_late(genpd, dev);
1000 }
1001
1002 /**
1003  * pm_genpd_suspend_noirq - Completion of suspend of device in an I/O PM domain.
1004  * @dev: Device to suspend.
1005  *
1006  * Stop the device and remove power from the domain if all devices in it have
1007  * been stopped.
1008  */
1009 static int pm_genpd_suspend_noirq(struct device *dev)
1010 {
1011         struct generic_pm_domain *genpd;
1012
1013         dev_dbg(dev, "%s()\n", __func__);
1014
1015         genpd = dev_to_genpd(dev);
1016         if (IS_ERR(genpd))
1017                 return -EINVAL;
1018
1019         if (genpd->suspend_power_off
1020             || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
1021                 return 0;
1022
1023         genpd_stop_dev(genpd, dev);
1024
1025         /*
1026          * Since all of the "noirq" callbacks are executed sequentially, it is
1027          * guaranteed that this function will never run twice in parallel for
1028          * the same PM domain, so it is not necessary to use locking here.
1029          */
1030         genpd->suspended_count++;
1031         pm_genpd_sync_poweroff(genpd);
1032
1033         return 0;
1034 }
1035
1036 /**
1037  * pm_genpd_resume_noirq - Start of resume of device in an I/O PM domain.
1038  * @dev: Device to resume.
1039  *
1040  * Restore power to the device's PM domain, if necessary, and start the device.
1041  */
1042 static int pm_genpd_resume_noirq(struct device *dev)
1043 {
1044         struct generic_pm_domain *genpd;
1045
1046         dev_dbg(dev, "%s()\n", __func__);
1047
1048         genpd = dev_to_genpd(dev);
1049         if (IS_ERR(genpd))
1050                 return -EINVAL;
1051
1052         if (genpd->suspend_power_off
1053             || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
1054                 return 0;
1055
1056         /*
1057          * Since all of the "noirq" callbacks are executed sequentially, it is
1058          * guaranteed that this function will never run twice in parallel for
1059          * the same PM domain, so it is not necessary to use locking here.
1060          */
1061         pm_genpd_sync_poweron(genpd);
1062         genpd->suspended_count--;
1063
1064         return genpd_start_dev(genpd, dev);
1065 }
1066
1067 /**
1068  * pm_genpd_resume_early - Early resume of a device in an I/O PM domain.
1069  * @dev: Device to resume.
1070  *
1071  * Carry out an early resume of a device under the assumption that its
1072  * pm_domain field points to the domain member of an object of type
1073  * struct generic_pm_domain representing a power domain consisting of I/O
1074  * devices.
1075  */
1076 static int pm_genpd_resume_early(struct device *dev)
1077 {
1078         struct generic_pm_domain *genpd;
1079
1080         dev_dbg(dev, "%s()\n", __func__);
1081
1082         genpd = dev_to_genpd(dev);
1083         if (IS_ERR(genpd))
1084                 return -EINVAL;
1085
1086         return genpd->suspend_power_off ? 0 : genpd_resume_early(genpd, dev);
1087 }
1088
1089 /**
1090  * pm_genpd_resume - Resume of device in an I/O PM domain.
1091  * @dev: Device to resume.
1092  *
1093  * Resume a device under the assumption that its pm_domain field points to the
1094  * domain member of an object of type struct generic_pm_domain representing
1095  * a power domain consisting of I/O devices.
1096  */
1097 static int pm_genpd_resume(struct device *dev)
1098 {
1099         struct generic_pm_domain *genpd;
1100
1101         dev_dbg(dev, "%s()\n", __func__);
1102
1103         genpd = dev_to_genpd(dev);
1104         if (IS_ERR(genpd))
1105                 return -EINVAL;
1106
1107         return genpd->suspend_power_off ? 0 : genpd_resume_dev(genpd, dev);
1108 }
1109
1110 /**
1111  * pm_genpd_freeze - Freezing a device in an I/O PM domain.
1112  * @dev: Device to freeze.
1113  *
1114  * Freeze a device under the assumption that its pm_domain field points to the
1115  * domain member of an object of type struct generic_pm_domain representing
1116  * a power domain consisting of I/O devices.
1117  */
1118 static int pm_genpd_freeze(struct device *dev)
1119 {
1120         struct generic_pm_domain *genpd;
1121
1122         dev_dbg(dev, "%s()\n", __func__);
1123
1124         genpd = dev_to_genpd(dev);
1125         if (IS_ERR(genpd))
1126                 return -EINVAL;
1127
1128         return genpd->suspend_power_off ? 0 : genpd_freeze_dev(genpd, dev);
1129 }
1130
1131 /**
1132  * pm_genpd_freeze_late - Late freeze of a device in an I/O PM domain.
1133  * @dev: Device to freeze.
1134  *
1135  * Carry out a late freeze of a device under the assumption that its
1136  * pm_domain field points to the domain member of an object of type
1137  * struct generic_pm_domain representing a power domain consisting of I/O
1138  * devices.
1139  */
1140 static int pm_genpd_freeze_late(struct device *dev)
1141 {
1142         struct generic_pm_domain *genpd;
1143
1144         dev_dbg(dev, "%s()\n", __func__);
1145
1146         genpd = dev_to_genpd(dev);
1147         if (IS_ERR(genpd))
1148                 return -EINVAL;
1149
1150         return genpd->suspend_power_off ? 0 : genpd_freeze_late(genpd, dev);
1151 }
1152
1153 /**
1154  * pm_genpd_freeze_noirq - Completion of freezing a device in an I/O PM domain.
1155  * @dev: Device to freeze.
1156  *
1157  * Carry out a late freeze of a device under the assumption that its
1158  * pm_domain field points to the domain member of an object of type
1159  * struct generic_pm_domain representing a power domain consisting of I/O
1160  * devices.
1161  */
1162 static int pm_genpd_freeze_noirq(struct device *dev)
1163 {
1164         struct generic_pm_domain *genpd;
1165
1166         dev_dbg(dev, "%s()\n", __func__);
1167
1168         genpd = dev_to_genpd(dev);
1169         if (IS_ERR(genpd))
1170                 return -EINVAL;
1171
1172         return genpd->suspend_power_off ? 0 : genpd_stop_dev(genpd, dev);
1173 }
1174
1175 /**
1176  * pm_genpd_thaw_noirq - Early thaw of device in an I/O PM domain.
1177  * @dev: Device to thaw.
1178  *
1179  * Start the device, unless power has been removed from the domain already
1180  * before the system transition.
1181  */
1182 static int pm_genpd_thaw_noirq(struct device *dev)
1183 {
1184         struct generic_pm_domain *genpd;
1185
1186         dev_dbg(dev, "%s()\n", __func__);
1187
1188         genpd = dev_to_genpd(dev);
1189         if (IS_ERR(genpd))
1190                 return -EINVAL;
1191
1192         return genpd->suspend_power_off ? 0 : genpd_start_dev(genpd, dev);
1193 }
1194
1195 /**
1196  * pm_genpd_thaw_early - Early thaw of device in an I/O PM domain.
1197  * @dev: Device to thaw.
1198  *
1199  * Carry out an early thaw of a device under the assumption that its
1200  * pm_domain field points to the domain member of an object of type
1201  * struct generic_pm_domain representing a power domain consisting of I/O
1202  * devices.
1203  */
1204 static int pm_genpd_thaw_early(struct device *dev)
1205 {
1206         struct generic_pm_domain *genpd;
1207
1208         dev_dbg(dev, "%s()\n", __func__);
1209
1210         genpd = dev_to_genpd(dev);
1211         if (IS_ERR(genpd))
1212                 return -EINVAL;
1213
1214         return genpd->suspend_power_off ? 0 : genpd_thaw_early(genpd, dev);
1215 }
1216
1217 /**
1218  * pm_genpd_thaw - Thaw a device belonging to an I/O power domain.
1219  * @dev: Device to thaw.
1220  *
1221  * Thaw a device under the assumption that its pm_domain field points to the
1222  * domain member of an object of type struct generic_pm_domain representing
1223  * a power domain consisting of I/O devices.
1224  */
1225 static int pm_genpd_thaw(struct device *dev)
1226 {
1227         struct generic_pm_domain *genpd;
1228
1229         dev_dbg(dev, "%s()\n", __func__);
1230
1231         genpd = dev_to_genpd(dev);
1232         if (IS_ERR(genpd))
1233                 return -EINVAL;
1234
1235         return genpd->suspend_power_off ? 0 : genpd_thaw_dev(genpd, dev);
1236 }
1237
1238 /**
1239  * pm_genpd_restore_noirq - Start of restore of device in an I/O PM domain.
1240  * @dev: Device to resume.
1241  *
1242  * Make sure the domain will be in the same power state as before the
1243  * hibernation the system is resuming from and start the device if necessary.
1244  */
1245 static int pm_genpd_restore_noirq(struct device *dev)
1246 {
1247         struct generic_pm_domain *genpd;
1248
1249         dev_dbg(dev, "%s()\n", __func__);
1250
1251         genpd = dev_to_genpd(dev);
1252         if (IS_ERR(genpd))
1253                 return -EINVAL;
1254
1255         /*
1256          * Since all of the "noirq" callbacks are executed sequentially, it is
1257          * guaranteed that this function will never run twice in parallel for
1258          * the same PM domain, so it is not necessary to use locking here.
1259          *
1260          * At this point suspended_count == 0 means we are being run for the
1261          * first time for the given domain in the present cycle.
1262          */
1263         if (genpd->suspended_count++ == 0) {
1264                 /*
1265                  * The boot kernel might put the domain into arbitrary state,
1266                  * so make it appear as powered off to pm_genpd_sync_poweron(),
1267                  * so that it tries to power it on in case it was really off.
1268                  */
1269                 genpd->status = GPD_STATE_POWER_OFF;
1270                 if (genpd->suspend_power_off) {
1271                         /*
1272                          * If the domain was off before the hibernation, make
1273                          * sure it will be off going forward.
1274                          */
1275                         if (genpd->power_off)
1276                                 genpd->power_off(genpd);
1277
1278                         return 0;
1279                 }
1280         }
1281
1282         if (genpd->suspend_power_off)
1283                 return 0;
1284
1285         pm_genpd_sync_poweron(genpd);
1286
1287         return genpd_start_dev(genpd, dev);
1288 }
1289
1290 /**
1291  * pm_genpd_complete - Complete power transition of a device in a power domain.
1292  * @dev: Device to complete the transition of.
1293  *
1294  * Complete a power transition of a device (during a system-wide power
1295  * transition) under the assumption that its pm_domain field points to the
1296  * domain member of an object of type struct generic_pm_domain representing
1297  * a power domain consisting of I/O devices.
1298  */
1299 static void pm_genpd_complete(struct device *dev)
1300 {
1301         struct generic_pm_domain *genpd;
1302         bool run_complete;
1303
1304         dev_dbg(dev, "%s()\n", __func__);
1305
1306         genpd = dev_to_genpd(dev);
1307         if (IS_ERR(genpd))
1308                 return;
1309
1310         mutex_lock(&genpd->lock);
1311
1312         run_complete = !genpd->suspend_power_off;
1313         if (--genpd->prepared_count == 0)
1314                 genpd->suspend_power_off = false;
1315
1316         mutex_unlock(&genpd->lock);
1317
1318         if (run_complete) {
1319                 pm_generic_complete(dev);
1320                 pm_runtime_set_active(dev);
1321                 pm_runtime_enable(dev);
1322                 pm_runtime_idle(dev);
1323         }
1324 }
1325
1326 /**
1327  * pm_genpd_syscore_switch - Switch power during system core suspend or resume.
1328  * @dev: Device that normally is marked as "always on" to switch power for.
1329  *
1330  * This routine may only be called during the system core (syscore) suspend or
1331  * resume phase for devices whose "always on" flags are set.
1332  */
1333 void pm_genpd_syscore_switch(struct device *dev, bool suspend)
1334 {
1335         struct generic_pm_domain *genpd;
1336
1337         genpd = dev_to_genpd(dev);
1338         if (!pm_genpd_present(genpd))
1339                 return;
1340
1341         if (suspend) {
1342                 genpd->suspended_count++;
1343                 pm_genpd_sync_poweroff(genpd);
1344         } else {
1345                 pm_genpd_sync_poweron(genpd);
1346                 genpd->suspended_count--;
1347         }
1348 }
1349 EXPORT_SYMBOL_GPL(pm_genpd_syscore_switch);
1350
1351 #else
1352
1353 #define pm_genpd_prepare                NULL
1354 #define pm_genpd_suspend                NULL
1355 #define pm_genpd_suspend_late           NULL
1356 #define pm_genpd_suspend_noirq          NULL
1357 #define pm_genpd_resume_early           NULL
1358 #define pm_genpd_resume_noirq           NULL
1359 #define pm_genpd_resume                 NULL
1360 #define pm_genpd_freeze                 NULL
1361 #define pm_genpd_freeze_late            NULL
1362 #define pm_genpd_freeze_noirq           NULL
1363 #define pm_genpd_thaw_early             NULL
1364 #define pm_genpd_thaw_noirq             NULL
1365 #define pm_genpd_thaw                   NULL
1366 #define pm_genpd_restore_noirq          NULL
1367 #define pm_genpd_complete               NULL
1368
1369 #endif /* CONFIG_PM_SLEEP */
1370
1371 static struct generic_pm_domain_data *__pm_genpd_alloc_dev_data(struct device *dev)
1372 {
1373         struct generic_pm_domain_data *gpd_data;
1374
1375         gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
1376         if (!gpd_data)
1377                 return NULL;
1378
1379         mutex_init(&gpd_data->lock);
1380         gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
1381         dev_pm_qos_add_notifier(dev, &gpd_data->nb);
1382         return gpd_data;
1383 }
1384
1385 static void __pm_genpd_free_dev_data(struct device *dev,
1386                                      struct generic_pm_domain_data *gpd_data)
1387 {
1388         dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
1389         kfree(gpd_data);
1390 }
1391
1392 /**
1393  * __pm_genpd_add_device - Add a device to an I/O PM domain.
1394  * @genpd: PM domain to add the device to.
1395  * @dev: Device to be added.
1396  * @td: Set of PM QoS timing parameters to attach to the device.
1397  */
1398 int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
1399                           struct gpd_timing_data *td)
1400 {
1401         struct generic_pm_domain_data *gpd_data_new, *gpd_data = NULL;
1402         struct pm_domain_data *pdd;
1403         int ret = 0;
1404
1405         dev_dbg(dev, "%s()\n", __func__);
1406
1407         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
1408                 return -EINVAL;
1409
1410         gpd_data_new = __pm_genpd_alloc_dev_data(dev);
1411         if (!gpd_data_new)
1412                 return -ENOMEM;
1413
1414         genpd_acquire_lock(genpd);
1415
1416         if (genpd->prepared_count > 0) {
1417                 ret = -EAGAIN;
1418                 goto out;
1419         }
1420
1421         list_for_each_entry(pdd, &genpd->dev_list, list_node)
1422                 if (pdd->dev == dev) {
1423                         ret = -EINVAL;
1424                         goto out;
1425                 }
1426
1427         ret = dev_pm_get_subsys_data(dev);
1428         if (ret)
1429                 goto out;
1430
1431         genpd->device_count++;
1432         genpd->max_off_time_changed = true;
1433
1434         spin_lock_irq(&dev->power.lock);
1435
1436         dev->pm_domain = &genpd->domain;
1437         if (dev->power.subsys_data->domain_data) {
1438                 gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
1439         } else {
1440                 gpd_data = gpd_data_new;
1441                 dev->power.subsys_data->domain_data = &gpd_data->base;
1442         }
1443         gpd_data->refcount++;
1444         if (td)
1445                 gpd_data->td = *td;
1446
1447         spin_unlock_irq(&dev->power.lock);
1448
1449         mutex_lock(&gpd_data->lock);
1450         gpd_data->base.dev = dev;
1451         list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
1452         gpd_data->need_restore = genpd->status == GPD_STATE_POWER_OFF;
1453         gpd_data->td.constraint_changed = true;
1454         gpd_data->td.effective_constraint_ns = -1;
1455         mutex_unlock(&gpd_data->lock);
1456
1457  out:
1458         genpd_release_lock(genpd);
1459
1460         if (gpd_data != gpd_data_new)
1461                 __pm_genpd_free_dev_data(dev, gpd_data_new);
1462
1463         return ret;
1464 }
1465
1466 /**
1467  * __pm_genpd_of_add_device - Add a device to an I/O PM domain.
1468  * @genpd_node: Device tree node pointer representing a PM domain to which the
1469  *   the device is added to.
1470  * @dev: Device to be added.
1471  * @td: Set of PM QoS timing parameters to attach to the device.
1472  */
1473 int __pm_genpd_of_add_device(struct device_node *genpd_node, struct device *dev,
1474                              struct gpd_timing_data *td)
1475 {
1476         struct generic_pm_domain *genpd = NULL, *gpd;
1477
1478         dev_dbg(dev, "%s()\n", __func__);
1479
1480         if (IS_ERR_OR_NULL(genpd_node) || IS_ERR_OR_NULL(dev))
1481                 return -EINVAL;
1482
1483         mutex_lock(&gpd_list_lock);
1484         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
1485                 if (gpd->of_node == genpd_node) {
1486                         genpd = gpd;
1487                         break;
1488                 }
1489         }
1490         mutex_unlock(&gpd_list_lock);
1491
1492         if (!genpd)
1493                 return -EINVAL;
1494
1495         return __pm_genpd_add_device(genpd, dev, td);
1496 }
1497
1498
1499 /**
1500  * __pm_genpd_name_add_device - Find I/O PM domain and add a device to it.
1501  * @domain_name: Name of the PM domain to add the device to.
1502  * @dev: Device to be added.
1503  * @td: Set of PM QoS timing parameters to attach to the device.
1504  */
1505 int __pm_genpd_name_add_device(const char *domain_name, struct device *dev,
1506                                struct gpd_timing_data *td)
1507 {
1508         return __pm_genpd_add_device(pm_genpd_lookup_name(domain_name), dev, td);
1509 }
1510
1511 /**
1512  * pm_genpd_remove_device - Remove a device from an I/O PM domain.
1513  * @genpd: PM domain to remove the device from.
1514  * @dev: Device to be removed.
1515  */
1516 int pm_genpd_remove_device(struct generic_pm_domain *genpd,
1517                            struct device *dev)
1518 {
1519         struct generic_pm_domain_data *gpd_data;
1520         struct pm_domain_data *pdd;
1521         bool remove = false;
1522         int ret = 0;
1523
1524         dev_dbg(dev, "%s()\n", __func__);
1525
1526         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)
1527             ||  IS_ERR_OR_NULL(dev->pm_domain)
1528             ||  pd_to_genpd(dev->pm_domain) != genpd)
1529                 return -EINVAL;
1530
1531         genpd_acquire_lock(genpd);
1532
1533         if (genpd->prepared_count > 0) {
1534                 ret = -EAGAIN;
1535                 goto out;
1536         }
1537
1538         genpd->device_count--;
1539         genpd->max_off_time_changed = true;
1540
1541         spin_lock_irq(&dev->power.lock);
1542
1543         dev->pm_domain = NULL;
1544         pdd = dev->power.subsys_data->domain_data;
1545         list_del_init(&pdd->list_node);
1546         gpd_data = to_gpd_data(pdd);
1547         if (--gpd_data->refcount == 0) {
1548                 dev->power.subsys_data->domain_data = NULL;
1549                 remove = true;
1550         }
1551
1552         spin_unlock_irq(&dev->power.lock);
1553
1554         mutex_lock(&gpd_data->lock);
1555         pdd->dev = NULL;
1556         mutex_unlock(&gpd_data->lock);
1557
1558         genpd_release_lock(genpd);
1559
1560         dev_pm_put_subsys_data(dev);
1561         if (remove)
1562                 __pm_genpd_free_dev_data(dev, gpd_data);
1563
1564         return 0;
1565
1566  out:
1567         genpd_release_lock(genpd);
1568
1569         return ret;
1570 }
1571
1572 /**
1573  * pm_genpd_dev_need_restore - Set/unset the device's "need restore" flag.
1574  * @dev: Device to set/unset the flag for.
1575  * @val: The new value of the device's "need restore" flag.
1576  */
1577 void pm_genpd_dev_need_restore(struct device *dev, bool val)
1578 {
1579         struct pm_subsys_data *psd;
1580         unsigned long flags;
1581
1582         spin_lock_irqsave(&dev->power.lock, flags);
1583
1584         psd = dev_to_psd(dev);
1585         if (psd && psd->domain_data)
1586                 to_gpd_data(psd->domain_data)->need_restore = val;
1587
1588         spin_unlock_irqrestore(&dev->power.lock, flags);
1589 }
1590 EXPORT_SYMBOL_GPL(pm_genpd_dev_need_restore);
1591
1592 /**
1593  * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
1594  * @genpd: Master PM domain to add the subdomain to.
1595  * @subdomain: Subdomain to be added.
1596  */
1597 int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
1598                            struct generic_pm_domain *subdomain)
1599 {
1600         struct gpd_link *link;
1601         int ret = 0;
1602
1603         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
1604             || genpd == subdomain)
1605                 return -EINVAL;
1606
1607  start:
1608         genpd_acquire_lock(genpd);
1609         mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
1610
1611         if (subdomain->status != GPD_STATE_POWER_OFF
1612             && subdomain->status != GPD_STATE_ACTIVE) {
1613                 mutex_unlock(&subdomain->lock);
1614                 genpd_release_lock(genpd);
1615                 goto start;
1616         }
1617
1618         if (genpd->status == GPD_STATE_POWER_OFF
1619             &&  subdomain->status != GPD_STATE_POWER_OFF) {
1620                 ret = -EINVAL;
1621                 goto out;
1622         }
1623
1624         list_for_each_entry(link, &genpd->master_links, master_node) {
1625                 if (link->slave == subdomain && link->master == genpd) {
1626                         ret = -EINVAL;
1627                         goto out;
1628                 }
1629         }
1630
1631         link = kzalloc(sizeof(*link), GFP_KERNEL);
1632         if (!link) {
1633                 ret = -ENOMEM;
1634                 goto out;
1635         }
1636         link->master = genpd;
1637         list_add_tail(&link->master_node, &genpd->master_links);
1638         link->slave = subdomain;
1639         list_add_tail(&link->slave_node, &subdomain->slave_links);
1640         if (subdomain->status != GPD_STATE_POWER_OFF)
1641                 genpd_sd_counter_inc(genpd);
1642
1643  out:
1644         mutex_unlock(&subdomain->lock);
1645         genpd_release_lock(genpd);
1646
1647         return ret;
1648 }
1649
1650 /**
1651  * pm_genpd_add_subdomain_names - Add a subdomain to an I/O PM domain.
1652  * @master_name: Name of the master PM domain to add the subdomain to.
1653  * @subdomain_name: Name of the subdomain to be added.
1654  */
1655 int pm_genpd_add_subdomain_names(const char *master_name,
1656                                  const char *subdomain_name)
1657 {
1658         struct generic_pm_domain *master = NULL, *subdomain = NULL, *gpd;
1659
1660         if (IS_ERR_OR_NULL(master_name) || IS_ERR_OR_NULL(subdomain_name))
1661                 return -EINVAL;
1662
1663         mutex_lock(&gpd_list_lock);
1664         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
1665                 if (!master && !strcmp(gpd->name, master_name))
1666                         master = gpd;
1667
1668                 if (!subdomain && !strcmp(gpd->name, subdomain_name))
1669                         subdomain = gpd;
1670
1671                 if (master && subdomain)
1672                         break;
1673         }
1674         mutex_unlock(&gpd_list_lock);
1675
1676         return pm_genpd_add_subdomain(master, subdomain);
1677 }
1678
1679 /**
1680  * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
1681  * @genpd: Master PM domain to remove the subdomain from.
1682  * @subdomain: Subdomain to be removed.
1683  */
1684 int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
1685                               struct generic_pm_domain *subdomain)
1686 {
1687         struct gpd_link *link;
1688         int ret = -EINVAL;
1689
1690         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
1691                 return -EINVAL;
1692
1693  start:
1694         genpd_acquire_lock(genpd);
1695
1696         list_for_each_entry(link, &genpd->master_links, master_node) {
1697                 if (link->slave != subdomain)
1698                         continue;
1699
1700                 mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
1701
1702                 if (subdomain->status != GPD_STATE_POWER_OFF
1703                     && subdomain->status != GPD_STATE_ACTIVE) {
1704                         mutex_unlock(&subdomain->lock);
1705                         genpd_release_lock(genpd);
1706                         goto start;
1707                 }
1708
1709                 list_del(&link->master_node);
1710                 list_del(&link->slave_node);
1711                 kfree(link);
1712                 if (subdomain->status != GPD_STATE_POWER_OFF)
1713                         genpd_sd_counter_dec(genpd);
1714
1715                 mutex_unlock(&subdomain->lock);
1716
1717                 ret = 0;
1718                 break;
1719         }
1720
1721         genpd_release_lock(genpd);
1722
1723         return ret;
1724 }
1725
1726 /**
1727  * pm_genpd_add_callbacks - Add PM domain callbacks to a given device.
1728  * @dev: Device to add the callbacks to.
1729  * @ops: Set of callbacks to add.
1730  * @td: Timing data to add to the device along with the callbacks (optional).
1731  *
1732  * Every call to this routine should be balanced with a call to
1733  * __pm_genpd_remove_callbacks() and they must not be nested.
1734  */
1735 int pm_genpd_add_callbacks(struct device *dev, struct gpd_dev_ops *ops,
1736                            struct gpd_timing_data *td)
1737 {
1738         struct generic_pm_domain_data *gpd_data_new, *gpd_data = NULL;
1739         int ret = 0;
1740
1741         if (!(dev && ops))
1742                 return -EINVAL;
1743
1744         gpd_data_new = __pm_genpd_alloc_dev_data(dev);
1745         if (!gpd_data_new)
1746                 return -ENOMEM;
1747
1748         pm_runtime_disable(dev);
1749         device_pm_lock();
1750
1751         ret = dev_pm_get_subsys_data(dev);
1752         if (ret)
1753                 goto out;
1754
1755         spin_lock_irq(&dev->power.lock);
1756
1757         if (dev->power.subsys_data->domain_data) {
1758                 gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
1759         } else {
1760                 gpd_data = gpd_data_new;
1761                 dev->power.subsys_data->domain_data = &gpd_data->base;
1762         }
1763         gpd_data->refcount++;
1764         gpd_data->ops = *ops;
1765         if (td)
1766                 gpd_data->td = *td;
1767
1768         spin_unlock_irq(&dev->power.lock);
1769
1770  out:
1771         device_pm_unlock();
1772         pm_runtime_enable(dev);
1773
1774         if (gpd_data != gpd_data_new)
1775                 __pm_genpd_free_dev_data(dev, gpd_data_new);
1776
1777         return ret;
1778 }
1779 EXPORT_SYMBOL_GPL(pm_genpd_add_callbacks);
1780
1781 /**
1782  * __pm_genpd_remove_callbacks - Remove PM domain callbacks from a given device.
1783  * @dev: Device to remove the callbacks from.
1784  * @clear_td: If set, clear the device's timing data too.
1785  *
1786  * This routine can only be called after pm_genpd_add_callbacks().
1787  */
1788 int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td)
1789 {
1790         struct generic_pm_domain_data *gpd_data = NULL;
1791         bool remove = false;
1792         int ret = 0;
1793
1794         if (!(dev && dev->power.subsys_data))
1795                 return -EINVAL;
1796
1797         pm_runtime_disable(dev);
1798         device_pm_lock();
1799
1800         spin_lock_irq(&dev->power.lock);
1801
1802         if (dev->power.subsys_data->domain_data) {
1803                 gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
1804                 gpd_data->ops = (struct gpd_dev_ops){ NULL };
1805                 if (clear_td)
1806                         gpd_data->td = (struct gpd_timing_data){ 0 };
1807
1808                 if (--gpd_data->refcount == 0) {
1809                         dev->power.subsys_data->domain_data = NULL;
1810                         remove = true;
1811                 }
1812         } else {
1813                 ret = -EINVAL;
1814         }
1815
1816         spin_unlock_irq(&dev->power.lock);
1817
1818         device_pm_unlock();
1819         pm_runtime_enable(dev);
1820
1821         if (ret)
1822                 return ret;
1823
1824         dev_pm_put_subsys_data(dev);
1825         if (remove)
1826                 __pm_genpd_free_dev_data(dev, gpd_data);
1827
1828         return 0;
1829 }
1830 EXPORT_SYMBOL_GPL(__pm_genpd_remove_callbacks);
1831
1832 /**
1833  * pm_genpd_attach_cpuidle - Connect the given PM domain with cpuidle.
1834  * @genpd: PM domain to be connected with cpuidle.
1835  * @state: cpuidle state this domain can disable/enable.
1836  *
1837  * Make a PM domain behave as though it contained a CPU core, that is, instead
1838  * of calling its power down routine it will enable the given cpuidle state so
1839  * that the cpuidle subsystem can power it down (if possible and desirable).
1840  */
1841 int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state)
1842 {
1843         struct cpuidle_driver *cpuidle_drv;
1844         struct gpd_cpu_data *cpu_data;
1845         struct cpuidle_state *idle_state;
1846         int ret = 0;
1847
1848         if (IS_ERR_OR_NULL(genpd) || state < 0)
1849                 return -EINVAL;
1850
1851         genpd_acquire_lock(genpd);
1852
1853         if (genpd->cpu_data) {
1854                 ret = -EEXIST;
1855                 goto out;
1856         }
1857         cpu_data = kzalloc(sizeof(*cpu_data), GFP_KERNEL);
1858         if (!cpu_data) {
1859                 ret = -ENOMEM;
1860                 goto out;
1861         }
1862         cpuidle_drv = cpuidle_driver_ref();
1863         if (!cpuidle_drv) {
1864                 ret = -ENODEV;
1865                 goto out;
1866         }
1867         if (cpuidle_drv->state_count <= state) {
1868                 ret = -EINVAL;
1869                 goto err;
1870         }
1871         idle_state = &cpuidle_drv->states[state];
1872         if (!idle_state->disabled) {
1873                 ret = -EAGAIN;
1874                 goto err;
1875         }
1876         cpu_data->idle_state = idle_state;
1877         cpu_data->saved_exit_latency = idle_state->exit_latency;
1878         genpd->cpu_data = cpu_data;
1879         genpd_recalc_cpu_exit_latency(genpd);
1880
1881  out:
1882         genpd_release_lock(genpd);
1883         return ret;
1884
1885  err:
1886         cpuidle_driver_unref();
1887         goto out;
1888 }
1889
1890 /**
1891  * pm_genpd_name_attach_cpuidle - Find PM domain and connect cpuidle to it.
1892  * @name: Name of the domain to connect to cpuidle.
1893  * @state: cpuidle state this domain can manipulate.
1894  */
1895 int pm_genpd_name_attach_cpuidle(const char *name, int state)
1896 {
1897         return pm_genpd_attach_cpuidle(pm_genpd_lookup_name(name), state);
1898 }
1899
1900 /**
1901  * pm_genpd_detach_cpuidle - Remove the cpuidle connection from a PM domain.
1902  * @genpd: PM domain to remove the cpuidle connection from.
1903  *
1904  * Remove the cpuidle connection set up by pm_genpd_attach_cpuidle() from the
1905  * given PM domain.
1906  */
1907 int pm_genpd_detach_cpuidle(struct generic_pm_domain *genpd)
1908 {
1909         struct gpd_cpu_data *cpu_data;
1910         struct cpuidle_state *idle_state;
1911         int ret = 0;
1912
1913         if (IS_ERR_OR_NULL(genpd))
1914                 return -EINVAL;
1915
1916         genpd_acquire_lock(genpd);
1917
1918         cpu_data = genpd->cpu_data;
1919         if (!cpu_data) {
1920                 ret = -ENODEV;
1921                 goto out;
1922         }
1923         idle_state = cpu_data->idle_state;
1924         if (!idle_state->disabled) {
1925                 ret = -EAGAIN;
1926                 goto out;
1927         }
1928         idle_state->exit_latency = cpu_data->saved_exit_latency;
1929         cpuidle_driver_unref();
1930         genpd->cpu_data = NULL;
1931         kfree(cpu_data);
1932
1933  out:
1934         genpd_release_lock(genpd);
1935         return ret;
1936 }
1937
1938 /**
1939  * pm_genpd_name_detach_cpuidle - Find PM domain and disconnect cpuidle from it.
1940  * @name: Name of the domain to disconnect cpuidle from.
1941  */
1942 int pm_genpd_name_detach_cpuidle(const char *name)
1943 {
1944         return pm_genpd_detach_cpuidle(pm_genpd_lookup_name(name));
1945 }
1946
1947 /* Default device callbacks for generic PM domains. */
1948
1949 /**
1950  * pm_genpd_default_save_state - Default "save device state" for PM domians.
1951  * @dev: Device to handle.
1952  */
1953 static int pm_genpd_default_save_state(struct device *dev)
1954 {
1955         int (*cb)(struct device *__dev);
1956
1957         cb = dev_gpd_data(dev)->ops.save_state;
1958         if (cb)
1959                 return cb(dev);
1960
1961         if (dev->type && dev->type->pm)
1962                 cb = dev->type->pm->runtime_suspend;
1963         else if (dev->class && dev->class->pm)
1964                 cb = dev->class->pm->runtime_suspend;
1965         else if (dev->bus && dev->bus->pm)
1966                 cb = dev->bus->pm->runtime_suspend;
1967         else
1968                 cb = NULL;
1969
1970         if (!cb && dev->driver && dev->driver->pm)
1971                 cb = dev->driver->pm->runtime_suspend;
1972
1973         return cb ? cb(dev) : 0;
1974 }
1975
1976 /**
1977  * pm_genpd_default_restore_state - Default PM domians "restore device state".
1978  * @dev: Device to handle.
1979  */
1980 static int pm_genpd_default_restore_state(struct device *dev)
1981 {
1982         int (*cb)(struct device *__dev);
1983
1984         cb = dev_gpd_data(dev)->ops.restore_state;
1985         if (cb)
1986                 return cb(dev);
1987
1988         if (dev->type && dev->type->pm)
1989                 cb = dev->type->pm->runtime_resume;
1990         else if (dev->class && dev->class->pm)
1991                 cb = dev->class->pm->runtime_resume;
1992         else if (dev->bus && dev->bus->pm)
1993                 cb = dev->bus->pm->runtime_resume;
1994         else
1995                 cb = NULL;
1996
1997         if (!cb && dev->driver && dev->driver->pm)
1998                 cb = dev->driver->pm->runtime_resume;
1999
2000         return cb ? cb(dev) : 0;
2001 }
2002
2003 #ifdef CONFIG_PM_SLEEP
2004
2005 /**
2006  * pm_genpd_default_suspend - Default "device suspend" for PM domians.
2007  * @dev: Device to handle.
2008  */
2009 static int pm_genpd_default_suspend(struct device *dev)
2010 {
2011         int (*cb)(struct device *__dev) = dev_gpd_data(dev)->ops.suspend;
2012
2013         return cb ? cb(dev) : pm_generic_suspend(dev);
2014 }
2015
2016 /**
2017  * pm_genpd_default_suspend_late - Default "late device suspend" for PM domians.
2018  * @dev: Device to handle.
2019  */
2020 static int pm_genpd_default_suspend_late(struct device *dev)
2021 {
2022         int (*cb)(struct device *__dev) = dev_gpd_data(dev)->ops.suspend_late;
2023
2024         return cb ? cb(dev) : pm_generic_suspend_late(dev);
2025 }
2026
2027 /**
2028  * pm_genpd_default_resume_early - Default "early device resume" for PM domians.
2029  * @dev: Device to handle.
2030  */
2031 static int pm_genpd_default_resume_early(struct device *dev)
2032 {
2033         int (*cb)(struct device *__dev) = dev_gpd_data(dev)->ops.resume_early;
2034
2035         return cb ? cb(dev) : pm_generic_resume_early(dev);
2036 }
2037
2038 /**
2039  * pm_genpd_default_resume - Default "device resume" for PM domians.
2040  * @dev: Device to handle.
2041  */
2042 static int pm_genpd_default_resume(struct device *dev)
2043 {
2044         int (*cb)(struct device *__dev) = dev_gpd_data(dev)->ops.resume;
2045
2046         return cb ? cb(dev) : pm_generic_resume(dev);
2047 }
2048
2049 /**
2050  * pm_genpd_default_freeze - Default "device freeze" for PM domians.
2051  * @dev: Device to handle.
2052  */
2053 static int pm_genpd_default_freeze(struct device *dev)
2054 {
2055         int (*cb)(struct device *__dev) = dev_gpd_data(dev)->ops.freeze;
2056
2057         return cb ? cb(dev) : pm_generic_freeze(dev);
2058 }
2059
2060 /**
2061  * pm_genpd_default_freeze_late - Default "late device freeze" for PM domians.
2062  * @dev: Device to handle.
2063  */
2064 static int pm_genpd_default_freeze_late(struct device *dev)
2065 {
2066         int (*cb)(struct device *__dev) = dev_gpd_data(dev)->ops.freeze_late;
2067
2068         return cb ? cb(dev) : pm_generic_freeze_late(dev);
2069 }
2070
2071 /**
2072  * pm_genpd_default_thaw_early - Default "early device thaw" for PM domians.
2073  * @dev: Device to handle.
2074  */
2075 static int pm_genpd_default_thaw_early(struct device *dev)
2076 {
2077         int (*cb)(struct device *__dev) = dev_gpd_data(dev)->ops.thaw_early;
2078
2079         return cb ? cb(dev) : pm_generic_thaw_early(dev);
2080 }
2081
2082 /**
2083  * pm_genpd_default_thaw - Default "device thaw" for PM domians.
2084  * @dev: Device to handle.
2085  */
2086 static int pm_genpd_default_thaw(struct device *dev)
2087 {
2088         int (*cb)(struct device *__dev) = dev_gpd_data(dev)->ops.thaw;
2089
2090         return cb ? cb(dev) : pm_generic_thaw(dev);
2091 }
2092
2093 #else /* !CONFIG_PM_SLEEP */
2094
2095 #define pm_genpd_default_suspend        NULL
2096 #define pm_genpd_default_suspend_late   NULL
2097 #define pm_genpd_default_resume_early   NULL
2098 #define pm_genpd_default_resume         NULL
2099 #define pm_genpd_default_freeze         NULL
2100 #define pm_genpd_default_freeze_late    NULL
2101 #define pm_genpd_default_thaw_early     NULL
2102 #define pm_genpd_default_thaw           NULL
2103
2104 #endif /* !CONFIG_PM_SLEEP */
2105
2106 /**
2107  * pm_genpd_init - Initialize a generic I/O PM domain object.
2108  * @genpd: PM domain object to initialize.
2109  * @gov: PM domain governor to associate with the domain (may be NULL).
2110  * @is_off: Initial value of the domain's power_is_off field.
2111  */
2112 void pm_genpd_init(struct generic_pm_domain *genpd,
2113                    struct dev_power_governor *gov, bool is_off)
2114 {
2115         if (IS_ERR_OR_NULL(genpd))
2116                 return;
2117
2118         INIT_LIST_HEAD(&genpd->master_links);
2119         INIT_LIST_HEAD(&genpd->slave_links);
2120         INIT_LIST_HEAD(&genpd->dev_list);
2121         mutex_init(&genpd->lock);
2122         genpd->gov = gov;
2123         INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
2124         genpd->in_progress = 0;
2125         atomic_set(&genpd->sd_count, 0);
2126         genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE;
2127         init_waitqueue_head(&genpd->status_wait_queue);
2128         genpd->poweroff_task = NULL;
2129         genpd->resume_count = 0;
2130         genpd->device_count = 0;
2131         genpd->max_off_time_ns = -1;
2132         genpd->max_off_time_changed = true;
2133         genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend;
2134         genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume;
2135         genpd->domain.ops.runtime_idle = pm_generic_runtime_idle;
2136         genpd->domain.ops.prepare = pm_genpd_prepare;
2137         genpd->domain.ops.suspend = pm_genpd_suspend;
2138         genpd->domain.ops.suspend_late = pm_genpd_suspend_late;
2139         genpd->domain.ops.suspend_noirq = pm_genpd_suspend_noirq;
2140         genpd->domain.ops.resume_noirq = pm_genpd_resume_noirq;
2141         genpd->domain.ops.resume_early = pm_genpd_resume_early;
2142         genpd->domain.ops.resume = pm_genpd_resume;
2143         genpd->domain.ops.freeze = pm_genpd_freeze;
2144         genpd->domain.ops.freeze_late = pm_genpd_freeze_late;
2145         genpd->domain.ops.freeze_noirq = pm_genpd_freeze_noirq;
2146         genpd->domain.ops.thaw_noirq = pm_genpd_thaw_noirq;
2147         genpd->domain.ops.thaw_early = pm_genpd_thaw_early;
2148         genpd->domain.ops.thaw = pm_genpd_thaw;
2149         genpd->domain.ops.poweroff = pm_genpd_suspend;
2150         genpd->domain.ops.poweroff_late = pm_genpd_suspend_late;
2151         genpd->domain.ops.poweroff_noirq = pm_genpd_suspend_noirq;
2152         genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq;
2153         genpd->domain.ops.restore_early = pm_genpd_resume_early;
2154         genpd->domain.ops.restore = pm_genpd_resume;
2155         genpd->domain.ops.complete = pm_genpd_complete;
2156         genpd->dev_ops.save_state = pm_genpd_default_save_state;
2157         genpd->dev_ops.restore_state = pm_genpd_default_restore_state;
2158         genpd->dev_ops.suspend = pm_genpd_default_suspend;
2159         genpd->dev_ops.suspend_late = pm_genpd_default_suspend_late;
2160         genpd->dev_ops.resume_early = pm_genpd_default_resume_early;
2161         genpd->dev_ops.resume = pm_genpd_default_resume;
2162         genpd->dev_ops.freeze = pm_genpd_default_freeze;
2163         genpd->dev_ops.freeze_late = pm_genpd_default_freeze_late;
2164         genpd->dev_ops.thaw_early = pm_genpd_default_thaw_early;
2165         genpd->dev_ops.thaw = pm_genpd_default_thaw;
2166         mutex_lock(&gpd_list_lock);
2167         list_add(&genpd->gpd_list_node, &gpd_list);
2168         mutex_unlock(&gpd_list_lock);
2169 }