domain.c revision 5063ce1571b73865cbdcd92db002e85809750c97
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/slab.h> 15#include <linux/err.h> 16#include <linux/sched.h> 17#include <linux/suspend.h> 18 19static LIST_HEAD(gpd_list); 20static DEFINE_MUTEX(gpd_list_lock); 21 22#ifdef CONFIG_PM 23 24static struct generic_pm_domain *dev_to_genpd(struct device *dev) 25{ 26 if (IS_ERR_OR_NULL(dev->pm_domain)) 27 return ERR_PTR(-EINVAL); 28 29 return pd_to_genpd(dev->pm_domain); 30} 31 32static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd) 33{ 34 bool ret = false; 35 36 if (!WARN_ON(atomic_read(&genpd->sd_count) == 0)) 37 ret = !!atomic_dec_and_test(&genpd->sd_count); 38 39 return ret; 40} 41 42static void genpd_sd_counter_inc(struct generic_pm_domain *genpd) 43{ 44 atomic_inc(&genpd->sd_count); 45 smp_mb__after_atomic_inc(); 46} 47 48static void genpd_acquire_lock(struct generic_pm_domain *genpd) 49{ 50 DEFINE_WAIT(wait); 51 52 mutex_lock(&genpd->lock); 53 /* 54 * Wait for the domain to transition into either the active, 55 * or the power off state. 56 */ 57 for (;;) { 58 prepare_to_wait(&genpd->status_wait_queue, &wait, 59 TASK_UNINTERRUPTIBLE); 60 if (genpd->status == GPD_STATE_ACTIVE 61 || genpd->status == GPD_STATE_POWER_OFF) 62 break; 63 mutex_unlock(&genpd->lock); 64 65 schedule(); 66 67 mutex_lock(&genpd->lock); 68 } 69 finish_wait(&genpd->status_wait_queue, &wait); 70} 71 72static void genpd_release_lock(struct generic_pm_domain *genpd) 73{ 74 mutex_unlock(&genpd->lock); 75} 76 77static void genpd_set_active(struct generic_pm_domain *genpd) 78{ 79 if (genpd->resume_count == 0) 80 genpd->status = GPD_STATE_ACTIVE; 81} 82 83/** 84 * __pm_genpd_poweron - Restore power to a given PM domain and its masters. 85 * @genpd: PM domain to power up. 86 * 87 * Restore power to @genpd and all of its masters so that it is possible to 88 * resume a device belonging to it. 89 */ 90int __pm_genpd_poweron(struct generic_pm_domain *genpd) 91 __releases(&genpd->lock) __acquires(&genpd->lock) 92{ 93 struct gpd_link *link; 94 DEFINE_WAIT(wait); 95 int ret = 0; 96 97 /* If the domain's master is being waited for, we have to wait too. */ 98 for (;;) { 99 prepare_to_wait(&genpd->status_wait_queue, &wait, 100 TASK_UNINTERRUPTIBLE); 101 if (genpd->status != GPD_STATE_WAIT_PARENT) 102 break; 103 mutex_unlock(&genpd->lock); 104 105 schedule(); 106 107 mutex_lock(&genpd->lock); 108 } 109 finish_wait(&genpd->status_wait_queue, &wait); 110 111 if (genpd->status == GPD_STATE_ACTIVE 112 || (genpd->prepared_count > 0 && genpd->suspend_power_off)) 113 return 0; 114 115 if (genpd->status != GPD_STATE_POWER_OFF) { 116 genpd_set_active(genpd); 117 return 0; 118 } 119 120 /* 121 * The list is guaranteed not to change while the loop below is being 122 * executed, unless one of the masters' .power_on() callbacks fiddles 123 * with it. 124 */ 125 list_for_each_entry(link, &genpd->slave_links, slave_node) { 126 genpd_sd_counter_inc(link->master); 127 genpd->status = GPD_STATE_WAIT_PARENT; 128 129 mutex_unlock(&genpd->lock); 130 131 ret = pm_genpd_poweron(link->master); 132 133 mutex_lock(&genpd->lock); 134 135 /* 136 * The "wait for parent" status is guaranteed not to change 137 * while the master is powering on. 138 */ 139 genpd->status = GPD_STATE_POWER_OFF; 140 wake_up_all(&genpd->status_wait_queue); 141 if (ret) { 142 genpd_sd_counter_dec(link->master); 143 goto err; 144 } 145 } 146 147 if (genpd->power_on) { 148 ret = genpd->power_on(genpd); 149 if (ret) 150 goto err; 151 } 152 153 genpd_set_active(genpd); 154 155 return 0; 156 157 err: 158 list_for_each_entry_continue_reverse(link, &genpd->slave_links, slave_node) 159 genpd_sd_counter_dec(link->master); 160 161 return ret; 162} 163 164/** 165 * pm_genpd_poweron - Restore power to a given PM domain and its masters. 166 * @genpd: PM domain to power up. 167 */ 168int pm_genpd_poweron(struct generic_pm_domain *genpd) 169{ 170 int ret; 171 172 mutex_lock(&genpd->lock); 173 ret = __pm_genpd_poweron(genpd); 174 mutex_unlock(&genpd->lock); 175 return ret; 176} 177 178#endif /* CONFIG_PM */ 179 180#ifdef CONFIG_PM_RUNTIME 181 182/** 183 * __pm_genpd_save_device - Save the pre-suspend state of a device. 184 * @dle: Device list entry of the device to save the state of. 185 * @genpd: PM domain the device belongs to. 186 */ 187static int __pm_genpd_save_device(struct dev_list_entry *dle, 188 struct generic_pm_domain *genpd) 189 __releases(&genpd->lock) __acquires(&genpd->lock) 190{ 191 struct device *dev = dle->dev; 192 struct device_driver *drv = dev->driver; 193 int ret = 0; 194 195 if (dle->need_restore) 196 return 0; 197 198 mutex_unlock(&genpd->lock); 199 200 if (drv && drv->pm && drv->pm->runtime_suspend) { 201 if (genpd->start_device) 202 genpd->start_device(dev); 203 204 ret = drv->pm->runtime_suspend(dev); 205 206 if (genpd->stop_device) 207 genpd->stop_device(dev); 208 } 209 210 mutex_lock(&genpd->lock); 211 212 if (!ret) 213 dle->need_restore = true; 214 215 return ret; 216} 217 218/** 219 * __pm_genpd_restore_device - Restore the pre-suspend state of a device. 220 * @dle: Device list entry of the device to restore the state of. 221 * @genpd: PM domain the device belongs to. 222 */ 223static void __pm_genpd_restore_device(struct dev_list_entry *dle, 224 struct generic_pm_domain *genpd) 225 __releases(&genpd->lock) __acquires(&genpd->lock) 226{ 227 struct device *dev = dle->dev; 228 struct device_driver *drv = dev->driver; 229 230 if (!dle->need_restore) 231 return; 232 233 mutex_unlock(&genpd->lock); 234 235 if (drv && drv->pm && drv->pm->runtime_resume) { 236 if (genpd->start_device) 237 genpd->start_device(dev); 238 239 drv->pm->runtime_resume(dev); 240 241 if (genpd->stop_device) 242 genpd->stop_device(dev); 243 } 244 245 mutex_lock(&genpd->lock); 246 247 dle->need_restore = false; 248} 249 250/** 251 * genpd_abort_poweroff - Check if a PM domain power off should be aborted. 252 * @genpd: PM domain to check. 253 * 254 * Return true if a PM domain's status changed to GPD_STATE_ACTIVE during 255 * a "power off" operation, which means that a "power on" has occured in the 256 * meantime, or if its resume_count field is different from zero, which means 257 * that one of its devices has been resumed in the meantime. 258 */ 259static bool genpd_abort_poweroff(struct generic_pm_domain *genpd) 260{ 261 return genpd->status == GPD_STATE_WAIT_PARENT 262 || genpd->status == GPD_STATE_ACTIVE || genpd->resume_count > 0; 263} 264 265/** 266 * genpd_queue_power_off_work - Queue up the execution of pm_genpd_poweroff(). 267 * @genpd: PM domait to power off. 268 * 269 * Queue up the execution of pm_genpd_poweroff() unless it's already been done 270 * before. 271 */ 272void genpd_queue_power_off_work(struct generic_pm_domain *genpd) 273{ 274 if (!work_pending(&genpd->power_off_work)) 275 queue_work(pm_wq, &genpd->power_off_work); 276} 277 278/** 279 * pm_genpd_poweroff - Remove power from a given PM domain. 280 * @genpd: PM domain to power down. 281 * 282 * If all of the @genpd's devices have been suspended and all of its subdomains 283 * have been powered down, run the runtime suspend callbacks provided by all of 284 * the @genpd's devices' drivers and remove power from @genpd. 285 */ 286static int pm_genpd_poweroff(struct generic_pm_domain *genpd) 287 __releases(&genpd->lock) __acquires(&genpd->lock) 288{ 289 struct dev_list_entry *dle; 290 struct gpd_link *link; 291 unsigned int not_suspended; 292 int ret = 0; 293 294 start: 295 /* 296 * Do not try to power off the domain in the following situations: 297 * (1) The domain is already in the "power off" state. 298 * (2) The domain is waiting for its master to power up. 299 * (3) One of the domain's devices is being resumed right now. 300 * (4) System suspend is in progress. 301 */ 302 if (genpd->status == GPD_STATE_POWER_OFF 303 || genpd->status == GPD_STATE_WAIT_PARENT 304 || genpd->resume_count > 0 || genpd->prepared_count > 0) 305 return 0; 306 307 if (atomic_read(&genpd->sd_count) > 0) 308 return -EBUSY; 309 310 not_suspended = 0; 311 list_for_each_entry(dle, &genpd->dev_list, node) 312 if (dle->dev->driver && !pm_runtime_suspended(dle->dev)) 313 not_suspended++; 314 315 if (not_suspended > genpd->in_progress) 316 return -EBUSY; 317 318 if (genpd->poweroff_task) { 319 /* 320 * Another instance of pm_genpd_poweroff() is executing 321 * callbacks, so tell it to start over and return. 322 */ 323 genpd->status = GPD_STATE_REPEAT; 324 return 0; 325 } 326 327 if (genpd->gov && genpd->gov->power_down_ok) { 328 if (!genpd->gov->power_down_ok(&genpd->domain)) 329 return -EAGAIN; 330 } 331 332 genpd->status = GPD_STATE_BUSY; 333 genpd->poweroff_task = current; 334 335 list_for_each_entry_reverse(dle, &genpd->dev_list, node) { 336 ret = atomic_read(&genpd->sd_count) == 0 ? 337 __pm_genpd_save_device(dle, genpd) : -EBUSY; 338 339 if (genpd_abort_poweroff(genpd)) 340 goto out; 341 342 if (ret) { 343 genpd_set_active(genpd); 344 goto out; 345 } 346 347 if (genpd->status == GPD_STATE_REPEAT) { 348 genpd->poweroff_task = NULL; 349 goto start; 350 } 351 } 352 353 if (genpd->power_off) { 354 if (atomic_read(&genpd->sd_count) > 0) { 355 ret = -EBUSY; 356 goto out; 357 } 358 359 /* 360 * If sd_count > 0 at this point, one of the subdomains hasn't 361 * managed to call pm_genpd_poweron() for the master yet after 362 * incrementing it. In that case pm_genpd_poweron() will wait 363 * for us to drop the lock, so we can call .power_off() and let 364 * the pm_genpd_poweron() restore power for us (this shouldn't 365 * happen very often). 366 */ 367 ret = genpd->power_off(genpd); 368 if (ret == -EBUSY) { 369 genpd_set_active(genpd); 370 goto out; 371 } 372 } 373 374 genpd->status = GPD_STATE_POWER_OFF; 375 376 list_for_each_entry(link, &genpd->slave_links, slave_node) { 377 genpd_sd_counter_dec(link->master); 378 genpd_queue_power_off_work(link->master); 379 } 380 381 out: 382 genpd->poweroff_task = NULL; 383 wake_up_all(&genpd->status_wait_queue); 384 return ret; 385} 386 387/** 388 * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0. 389 * @work: Work structure used for scheduling the execution of this function. 390 */ 391static void genpd_power_off_work_fn(struct work_struct *work) 392{ 393 struct generic_pm_domain *genpd; 394 395 genpd = container_of(work, struct generic_pm_domain, power_off_work); 396 397 genpd_acquire_lock(genpd); 398 pm_genpd_poweroff(genpd); 399 genpd_release_lock(genpd); 400} 401 402/** 403 * pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain. 404 * @dev: Device to suspend. 405 * 406 * Carry out a runtime suspend of a device under the assumption that its 407 * pm_domain field points to the domain member of an object of type 408 * struct generic_pm_domain representing a PM domain consisting of I/O devices. 409 */ 410static int pm_genpd_runtime_suspend(struct device *dev) 411{ 412 struct generic_pm_domain *genpd; 413 414 dev_dbg(dev, "%s()\n", __func__); 415 416 genpd = dev_to_genpd(dev); 417 if (IS_ERR(genpd)) 418 return -EINVAL; 419 420 if (genpd->stop_device) { 421 int ret = genpd->stop_device(dev); 422 if (ret) 423 return ret; 424 } 425 426 mutex_lock(&genpd->lock); 427 genpd->in_progress++; 428 pm_genpd_poweroff(genpd); 429 genpd->in_progress--; 430 mutex_unlock(&genpd->lock); 431 432 return 0; 433} 434 435/** 436 * __pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain. 437 * @dev: Device to resume. 438 * @genpd: PM domain the device belongs to. 439 */ 440static void __pm_genpd_runtime_resume(struct device *dev, 441 struct generic_pm_domain *genpd) 442{ 443 struct dev_list_entry *dle; 444 445 list_for_each_entry(dle, &genpd->dev_list, node) { 446 if (dle->dev == dev) { 447 __pm_genpd_restore_device(dle, genpd); 448 break; 449 } 450 } 451} 452 453/** 454 * pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain. 455 * @dev: Device to resume. 456 * 457 * Carry out a runtime resume of a device under the assumption that its 458 * pm_domain field points to the domain member of an object of type 459 * struct generic_pm_domain representing a PM domain consisting of I/O devices. 460 */ 461static int pm_genpd_runtime_resume(struct device *dev) 462{ 463 struct generic_pm_domain *genpd; 464 DEFINE_WAIT(wait); 465 int ret; 466 467 dev_dbg(dev, "%s()\n", __func__); 468 469 genpd = dev_to_genpd(dev); 470 if (IS_ERR(genpd)) 471 return -EINVAL; 472 473 mutex_lock(&genpd->lock); 474 ret = __pm_genpd_poweron(genpd); 475 if (ret) { 476 mutex_unlock(&genpd->lock); 477 return ret; 478 } 479 genpd->status = GPD_STATE_BUSY; 480 genpd->resume_count++; 481 for (;;) { 482 prepare_to_wait(&genpd->status_wait_queue, &wait, 483 TASK_UNINTERRUPTIBLE); 484 /* 485 * If current is the powering off task, we have been called 486 * reentrantly from one of the device callbacks, so we should 487 * not wait. 488 */ 489 if (!genpd->poweroff_task || genpd->poweroff_task == current) 490 break; 491 mutex_unlock(&genpd->lock); 492 493 schedule(); 494 495 mutex_lock(&genpd->lock); 496 } 497 finish_wait(&genpd->status_wait_queue, &wait); 498 __pm_genpd_runtime_resume(dev, genpd); 499 genpd->resume_count--; 500 genpd_set_active(genpd); 501 wake_up_all(&genpd->status_wait_queue); 502 mutex_unlock(&genpd->lock); 503 504 if (genpd->start_device) 505 genpd->start_device(dev); 506 507 return 0; 508} 509 510/** 511 * pm_genpd_poweroff_unused - Power off all PM domains with no devices in use. 512 */ 513void pm_genpd_poweroff_unused(void) 514{ 515 struct generic_pm_domain *genpd; 516 517 mutex_lock(&gpd_list_lock); 518 519 list_for_each_entry(genpd, &gpd_list, gpd_list_node) 520 genpd_queue_power_off_work(genpd); 521 522 mutex_unlock(&gpd_list_lock); 523} 524 525#else 526 527static inline void genpd_power_off_work_fn(struct work_struct *work) {} 528static inline void __pm_genpd_runtime_resume(struct device *dev, 529 struct generic_pm_domain *genpd) {} 530 531#define pm_genpd_runtime_suspend NULL 532#define pm_genpd_runtime_resume NULL 533 534#endif /* CONFIG_PM_RUNTIME */ 535 536#ifdef CONFIG_PM_SLEEP 537 538/** 539 * pm_genpd_sync_poweroff - Synchronously power off a PM domain and its masters. 540 * @genpd: PM domain to power off, if possible. 541 * 542 * Check if the given PM domain can be powered off (during system suspend or 543 * hibernation) and do that if so. Also, in that case propagate to its masters. 544 * 545 * This function is only called in "noirq" stages of system power transitions, 546 * so it need not acquire locks (all of the "noirq" callbacks are executed 547 * sequentially, so it is guaranteed that it will never run twice in parallel). 548 */ 549static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd) 550{ 551 struct gpd_link *link; 552 553 if (genpd->status == GPD_STATE_POWER_OFF) 554 return; 555 556 if (genpd->suspended_count != genpd->device_count 557 || atomic_read(&genpd->sd_count) > 0) 558 return; 559 560 if (genpd->power_off) 561 genpd->power_off(genpd); 562 563 genpd->status = GPD_STATE_POWER_OFF; 564 565 list_for_each_entry(link, &genpd->slave_links, slave_node) { 566 genpd_sd_counter_dec(link->master); 567 pm_genpd_sync_poweroff(link->master); 568 } 569} 570 571/** 572 * resume_needed - Check whether to resume a device before system suspend. 573 * @dev: Device to check. 574 * @genpd: PM domain the device belongs to. 575 * 576 * There are two cases in which a device that can wake up the system from sleep 577 * states should be resumed by pm_genpd_prepare(): (1) if the device is enabled 578 * to wake up the system and it has to remain active for this purpose while the 579 * system is in the sleep state and (2) if the device is not enabled to wake up 580 * the system from sleep states and it generally doesn't generate wakeup signals 581 * by itself (those signals are generated on its behalf by other parts of the 582 * system). In the latter case it may be necessary to reconfigure the device's 583 * wakeup settings during system suspend, because it may have been set up to 584 * signal remote wakeup from the system's working state as needed by runtime PM. 585 * Return 'true' in either of the above cases. 586 */ 587static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd) 588{ 589 bool active_wakeup; 590 591 if (!device_can_wakeup(dev)) 592 return false; 593 594 active_wakeup = genpd->active_wakeup && genpd->active_wakeup(dev); 595 return device_may_wakeup(dev) ? active_wakeup : !active_wakeup; 596} 597 598/** 599 * pm_genpd_prepare - Start power transition of a device in a PM domain. 600 * @dev: Device to start the transition of. 601 * 602 * Start a power transition of a device (during a system-wide power transition) 603 * under the assumption that its pm_domain field points to the domain member of 604 * an object of type struct generic_pm_domain representing a PM domain 605 * consisting of I/O devices. 606 */ 607static int pm_genpd_prepare(struct device *dev) 608{ 609 struct generic_pm_domain *genpd; 610 int ret; 611 612 dev_dbg(dev, "%s()\n", __func__); 613 614 genpd = dev_to_genpd(dev); 615 if (IS_ERR(genpd)) 616 return -EINVAL; 617 618 /* 619 * If a wakeup request is pending for the device, it should be woken up 620 * at this point and a system wakeup event should be reported if it's 621 * set up to wake up the system from sleep states. 622 */ 623 pm_runtime_get_noresume(dev); 624 if (pm_runtime_barrier(dev) && device_may_wakeup(dev)) 625 pm_wakeup_event(dev, 0); 626 627 if (pm_wakeup_pending()) { 628 pm_runtime_put_sync(dev); 629 return -EBUSY; 630 } 631 632 if (resume_needed(dev, genpd)) 633 pm_runtime_resume(dev); 634 635 genpd_acquire_lock(genpd); 636 637 if (genpd->prepared_count++ == 0) 638 genpd->suspend_power_off = genpd->status == GPD_STATE_POWER_OFF; 639 640 genpd_release_lock(genpd); 641 642 if (genpd->suspend_power_off) { 643 pm_runtime_put_noidle(dev); 644 return 0; 645 } 646 647 /* 648 * The PM domain must be in the GPD_STATE_ACTIVE state at this point, 649 * so pm_genpd_poweron() will return immediately, but if the device 650 * is suspended (e.g. it's been stopped by .stop_device()), we need 651 * to make it operational. 652 */ 653 pm_runtime_resume(dev); 654 __pm_runtime_disable(dev, false); 655 656 ret = pm_generic_prepare(dev); 657 if (ret) { 658 mutex_lock(&genpd->lock); 659 660 if (--genpd->prepared_count == 0) 661 genpd->suspend_power_off = false; 662 663 mutex_unlock(&genpd->lock); 664 pm_runtime_enable(dev); 665 } 666 667 pm_runtime_put_sync(dev); 668 return ret; 669} 670 671/** 672 * pm_genpd_suspend - Suspend a device belonging to an I/O PM domain. 673 * @dev: Device to suspend. 674 * 675 * Suspend a device under the assumption that its pm_domain field points to the 676 * domain member of an object of type struct generic_pm_domain representing 677 * a PM domain consisting of I/O devices. 678 */ 679static int pm_genpd_suspend(struct device *dev) 680{ 681 struct generic_pm_domain *genpd; 682 683 dev_dbg(dev, "%s()\n", __func__); 684 685 genpd = dev_to_genpd(dev); 686 if (IS_ERR(genpd)) 687 return -EINVAL; 688 689 return genpd->suspend_power_off ? 0 : pm_generic_suspend(dev); 690} 691 692/** 693 * pm_genpd_suspend_noirq - Late suspend of a device from an I/O PM domain. 694 * @dev: Device to suspend. 695 * 696 * Carry out a late suspend of a device under the assumption that its 697 * pm_domain field points to the domain member of an object of type 698 * struct generic_pm_domain representing a PM domain consisting of I/O devices. 699 */ 700static int pm_genpd_suspend_noirq(struct device *dev) 701{ 702 struct generic_pm_domain *genpd; 703 int ret; 704 705 dev_dbg(dev, "%s()\n", __func__); 706 707 genpd = dev_to_genpd(dev); 708 if (IS_ERR(genpd)) 709 return -EINVAL; 710 711 if (genpd->suspend_power_off) 712 return 0; 713 714 ret = pm_generic_suspend_noirq(dev); 715 if (ret) 716 return ret; 717 718 if (device_may_wakeup(dev) 719 && genpd->active_wakeup && genpd->active_wakeup(dev)) 720 return 0; 721 722 if (genpd->stop_device) 723 genpd->stop_device(dev); 724 725 /* 726 * Since all of the "noirq" callbacks are executed sequentially, it is 727 * guaranteed that this function will never run twice in parallel for 728 * the same PM domain, so it is not necessary to use locking here. 729 */ 730 genpd->suspended_count++; 731 pm_genpd_sync_poweroff(genpd); 732 733 return 0; 734} 735 736/** 737 * pm_genpd_resume_noirq - Early resume of a device from an I/O power domain. 738 * @dev: Device to resume. 739 * 740 * Carry out an early resume of a device under the assumption that its 741 * pm_domain field points to the domain member of an object of type 742 * struct generic_pm_domain representing a power domain consisting of I/O 743 * devices. 744 */ 745static int pm_genpd_resume_noirq(struct device *dev) 746{ 747 struct generic_pm_domain *genpd; 748 749 dev_dbg(dev, "%s()\n", __func__); 750 751 genpd = dev_to_genpd(dev); 752 if (IS_ERR(genpd)) 753 return -EINVAL; 754 755 if (genpd->suspend_power_off) 756 return 0; 757 758 /* 759 * Since all of the "noirq" callbacks are executed sequentially, it is 760 * guaranteed that this function will never run twice in parallel for 761 * the same PM domain, so it is not necessary to use locking here. 762 */ 763 pm_genpd_poweron(genpd); 764 genpd->suspended_count--; 765 if (genpd->start_device) 766 genpd->start_device(dev); 767 768 return pm_generic_resume_noirq(dev); 769} 770 771/** 772 * pm_genpd_resume - Resume a device belonging to an I/O power domain. 773 * @dev: Device to resume. 774 * 775 * Resume a device under the assumption that its pm_domain field points to the 776 * domain member of an object of type struct generic_pm_domain representing 777 * a power domain consisting of I/O devices. 778 */ 779static int pm_genpd_resume(struct device *dev) 780{ 781 struct generic_pm_domain *genpd; 782 783 dev_dbg(dev, "%s()\n", __func__); 784 785 genpd = dev_to_genpd(dev); 786 if (IS_ERR(genpd)) 787 return -EINVAL; 788 789 return genpd->suspend_power_off ? 0 : pm_generic_resume(dev); 790} 791 792/** 793 * pm_genpd_freeze - Freeze a device belonging to an I/O power domain. 794 * @dev: Device to freeze. 795 * 796 * Freeze a device under the assumption that its pm_domain field points to the 797 * domain member of an object of type struct generic_pm_domain representing 798 * a power domain consisting of I/O devices. 799 */ 800static int pm_genpd_freeze(struct device *dev) 801{ 802 struct generic_pm_domain *genpd; 803 804 dev_dbg(dev, "%s()\n", __func__); 805 806 genpd = dev_to_genpd(dev); 807 if (IS_ERR(genpd)) 808 return -EINVAL; 809 810 return genpd->suspend_power_off ? 0 : pm_generic_freeze(dev); 811} 812 813/** 814 * pm_genpd_freeze_noirq - Late freeze of a device from an I/O power domain. 815 * @dev: Device to freeze. 816 * 817 * Carry out a late freeze of a device under the assumption that its 818 * pm_domain field points to the domain member of an object of type 819 * struct generic_pm_domain representing a power domain consisting of I/O 820 * devices. 821 */ 822static int pm_genpd_freeze_noirq(struct device *dev) 823{ 824 struct generic_pm_domain *genpd; 825 int ret; 826 827 dev_dbg(dev, "%s()\n", __func__); 828 829 genpd = dev_to_genpd(dev); 830 if (IS_ERR(genpd)) 831 return -EINVAL; 832 833 if (genpd->suspend_power_off) 834 return 0; 835 836 ret = pm_generic_freeze_noirq(dev); 837 if (ret) 838 return ret; 839 840 if (genpd->stop_device) 841 genpd->stop_device(dev); 842 843 return 0; 844} 845 846/** 847 * pm_genpd_thaw_noirq - Early thaw of a device from an I/O power domain. 848 * @dev: Device to thaw. 849 * 850 * Carry out an early thaw of a device under the assumption that its 851 * pm_domain field points to the domain member of an object of type 852 * struct generic_pm_domain representing a power domain consisting of I/O 853 * devices. 854 */ 855static int pm_genpd_thaw_noirq(struct device *dev) 856{ 857 struct generic_pm_domain *genpd; 858 859 dev_dbg(dev, "%s()\n", __func__); 860 861 genpd = dev_to_genpd(dev); 862 if (IS_ERR(genpd)) 863 return -EINVAL; 864 865 if (genpd->suspend_power_off) 866 return 0; 867 868 if (genpd->start_device) 869 genpd->start_device(dev); 870 871 return pm_generic_thaw_noirq(dev); 872} 873 874/** 875 * pm_genpd_thaw - Thaw a device belonging to an I/O power domain. 876 * @dev: Device to thaw. 877 * 878 * Thaw a device under the assumption that its pm_domain field points to the 879 * domain member of an object of type struct generic_pm_domain representing 880 * a power domain consisting of I/O devices. 881 */ 882static int pm_genpd_thaw(struct device *dev) 883{ 884 struct generic_pm_domain *genpd; 885 886 dev_dbg(dev, "%s()\n", __func__); 887 888 genpd = dev_to_genpd(dev); 889 if (IS_ERR(genpd)) 890 return -EINVAL; 891 892 return genpd->suspend_power_off ? 0 : pm_generic_thaw(dev); 893} 894 895/** 896 * pm_genpd_dev_poweroff - Power off a device belonging to an I/O PM domain. 897 * @dev: Device to suspend. 898 * 899 * Power off a device under the assumption that its pm_domain field points to 900 * the domain member of an object of type struct generic_pm_domain representing 901 * a PM domain consisting of I/O devices. 902 */ 903static int pm_genpd_dev_poweroff(struct device *dev) 904{ 905 struct generic_pm_domain *genpd; 906 907 dev_dbg(dev, "%s()\n", __func__); 908 909 genpd = dev_to_genpd(dev); 910 if (IS_ERR(genpd)) 911 return -EINVAL; 912 913 return genpd->suspend_power_off ? 0 : pm_generic_poweroff(dev); 914} 915 916/** 917 * pm_genpd_dev_poweroff_noirq - Late power off of a device from a PM domain. 918 * @dev: Device to suspend. 919 * 920 * Carry out a late powering off of a device under the assumption that its 921 * pm_domain field points to the domain member of an object of type 922 * struct generic_pm_domain representing a PM domain consisting of I/O devices. 923 */ 924static int pm_genpd_dev_poweroff_noirq(struct device *dev) 925{ 926 struct generic_pm_domain *genpd; 927 int ret; 928 929 dev_dbg(dev, "%s()\n", __func__); 930 931 genpd = dev_to_genpd(dev); 932 if (IS_ERR(genpd)) 933 return -EINVAL; 934 935 if (genpd->suspend_power_off) 936 return 0; 937 938 ret = pm_generic_poweroff_noirq(dev); 939 if (ret) 940 return ret; 941 942 if (device_may_wakeup(dev) 943 && genpd->active_wakeup && genpd->active_wakeup(dev)) 944 return 0; 945 946 if (genpd->stop_device) 947 genpd->stop_device(dev); 948 949 /* 950 * Since all of the "noirq" callbacks are executed sequentially, it is 951 * guaranteed that this function will never run twice in parallel for 952 * the same PM domain, so it is not necessary to use locking here. 953 */ 954 genpd->suspended_count++; 955 pm_genpd_sync_poweroff(genpd); 956 957 return 0; 958} 959 960/** 961 * pm_genpd_restore_noirq - Early restore of a device from an I/O power domain. 962 * @dev: Device to resume. 963 * 964 * Carry out an early restore of a device under the assumption that its 965 * pm_domain field points to the domain member of an object of type 966 * struct generic_pm_domain representing a power domain consisting of I/O 967 * devices. 968 */ 969static int pm_genpd_restore_noirq(struct device *dev) 970{ 971 struct generic_pm_domain *genpd; 972 973 dev_dbg(dev, "%s()\n", __func__); 974 975 genpd = dev_to_genpd(dev); 976 if (IS_ERR(genpd)) 977 return -EINVAL; 978 979 /* 980 * Since all of the "noirq" callbacks are executed sequentially, it is 981 * guaranteed that this function will never run twice in parallel for 982 * the same PM domain, so it is not necessary to use locking here. 983 */ 984 genpd->status = GPD_STATE_POWER_OFF; 985 if (genpd->suspend_power_off) { 986 /* 987 * The boot kernel might put the domain into the power on state, 988 * so make sure it really is powered off. 989 */ 990 if (genpd->power_off) 991 genpd->power_off(genpd); 992 return 0; 993 } 994 995 pm_genpd_poweron(genpd); 996 genpd->suspended_count--; 997 if (genpd->start_device) 998 genpd->start_device(dev); 999 1000 return pm_generic_restore_noirq(dev); 1001} 1002 1003/** 1004 * pm_genpd_restore - Restore a device belonging to an I/O power domain. 1005 * @dev: Device to resume. 1006 * 1007 * Restore a device under the assumption that its pm_domain field points to the 1008 * domain member of an object of type struct generic_pm_domain representing 1009 * a power domain consisting of I/O devices. 1010 */ 1011static int pm_genpd_restore(struct device *dev) 1012{ 1013 struct generic_pm_domain *genpd; 1014 1015 dev_dbg(dev, "%s()\n", __func__); 1016 1017 genpd = dev_to_genpd(dev); 1018 if (IS_ERR(genpd)) 1019 return -EINVAL; 1020 1021 return genpd->suspend_power_off ? 0 : pm_generic_restore(dev); 1022} 1023 1024/** 1025 * pm_genpd_complete - Complete power transition of a device in a power domain. 1026 * @dev: Device to complete the transition of. 1027 * 1028 * Complete a power transition of a device (during a system-wide power 1029 * transition) under the assumption that its pm_domain field points to the 1030 * domain member of an object of type struct generic_pm_domain representing 1031 * a power domain consisting of I/O devices. 1032 */ 1033static void pm_genpd_complete(struct device *dev) 1034{ 1035 struct generic_pm_domain *genpd; 1036 bool run_complete; 1037 1038 dev_dbg(dev, "%s()\n", __func__); 1039 1040 genpd = dev_to_genpd(dev); 1041 if (IS_ERR(genpd)) 1042 return; 1043 1044 mutex_lock(&genpd->lock); 1045 1046 run_complete = !genpd->suspend_power_off; 1047 if (--genpd->prepared_count == 0) 1048 genpd->suspend_power_off = false; 1049 1050 mutex_unlock(&genpd->lock); 1051 1052 if (run_complete) { 1053 pm_generic_complete(dev); 1054 pm_runtime_set_active(dev); 1055 pm_runtime_enable(dev); 1056 pm_runtime_idle(dev); 1057 } 1058} 1059 1060#else 1061 1062#define pm_genpd_prepare NULL 1063#define pm_genpd_suspend NULL 1064#define pm_genpd_suspend_noirq NULL 1065#define pm_genpd_resume_noirq NULL 1066#define pm_genpd_resume NULL 1067#define pm_genpd_freeze NULL 1068#define pm_genpd_freeze_noirq NULL 1069#define pm_genpd_thaw_noirq NULL 1070#define pm_genpd_thaw NULL 1071#define pm_genpd_dev_poweroff_noirq NULL 1072#define pm_genpd_dev_poweroff NULL 1073#define pm_genpd_restore_noirq NULL 1074#define pm_genpd_restore NULL 1075#define pm_genpd_complete NULL 1076 1077#endif /* CONFIG_PM_SLEEP */ 1078 1079/** 1080 * pm_genpd_add_device - Add a device to an I/O PM domain. 1081 * @genpd: PM domain to add the device to. 1082 * @dev: Device to be added. 1083 */ 1084int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev) 1085{ 1086 struct dev_list_entry *dle; 1087 int ret = 0; 1088 1089 dev_dbg(dev, "%s()\n", __func__); 1090 1091 if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)) 1092 return -EINVAL; 1093 1094 genpd_acquire_lock(genpd); 1095 1096 if (genpd->status == GPD_STATE_POWER_OFF) { 1097 ret = -EINVAL; 1098 goto out; 1099 } 1100 1101 if (genpd->prepared_count > 0) { 1102 ret = -EAGAIN; 1103 goto out; 1104 } 1105 1106 list_for_each_entry(dle, &genpd->dev_list, node) 1107 if (dle->dev == dev) { 1108 ret = -EINVAL; 1109 goto out; 1110 } 1111 1112 dle = kzalloc(sizeof(*dle), GFP_KERNEL); 1113 if (!dle) { 1114 ret = -ENOMEM; 1115 goto out; 1116 } 1117 1118 dle->dev = dev; 1119 dle->need_restore = false; 1120 list_add_tail(&dle->node, &genpd->dev_list); 1121 genpd->device_count++; 1122 1123 spin_lock_irq(&dev->power.lock); 1124 dev->pm_domain = &genpd->domain; 1125 spin_unlock_irq(&dev->power.lock); 1126 1127 out: 1128 genpd_release_lock(genpd); 1129 1130 return ret; 1131} 1132 1133/** 1134 * pm_genpd_remove_device - Remove a device from an I/O PM domain. 1135 * @genpd: PM domain to remove the device from. 1136 * @dev: Device to be removed. 1137 */ 1138int pm_genpd_remove_device(struct generic_pm_domain *genpd, 1139 struct device *dev) 1140{ 1141 struct dev_list_entry *dle; 1142 int ret = -EINVAL; 1143 1144 dev_dbg(dev, "%s()\n", __func__); 1145 1146 if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)) 1147 return -EINVAL; 1148 1149 genpd_acquire_lock(genpd); 1150 1151 if (genpd->prepared_count > 0) { 1152 ret = -EAGAIN; 1153 goto out; 1154 } 1155 1156 list_for_each_entry(dle, &genpd->dev_list, node) { 1157 if (dle->dev != dev) 1158 continue; 1159 1160 spin_lock_irq(&dev->power.lock); 1161 dev->pm_domain = NULL; 1162 spin_unlock_irq(&dev->power.lock); 1163 1164 genpd->device_count--; 1165 list_del(&dle->node); 1166 kfree(dle); 1167 1168 ret = 0; 1169 break; 1170 } 1171 1172 out: 1173 genpd_release_lock(genpd); 1174 1175 return ret; 1176} 1177 1178/** 1179 * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain. 1180 * @genpd: Master PM domain to add the subdomain to. 1181 * @new_subdomain: Subdomain to be added. 1182 */ 1183int pm_genpd_add_subdomain(struct generic_pm_domain *genpd, 1184 struct generic_pm_domain *new_subdomain) 1185{ 1186 struct gpd_link *link; 1187 int ret = 0; 1188 1189 if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(new_subdomain)) 1190 return -EINVAL; 1191 1192 start: 1193 genpd_acquire_lock(genpd); 1194 mutex_lock_nested(&new_subdomain->lock, SINGLE_DEPTH_NESTING); 1195 1196 if (new_subdomain->status != GPD_STATE_POWER_OFF 1197 && new_subdomain->status != GPD_STATE_ACTIVE) { 1198 mutex_unlock(&new_subdomain->lock); 1199 genpd_release_lock(genpd); 1200 goto start; 1201 } 1202 1203 if (genpd->status == GPD_STATE_POWER_OFF 1204 && new_subdomain->status != GPD_STATE_POWER_OFF) { 1205 ret = -EINVAL; 1206 goto out; 1207 } 1208 1209 list_for_each_entry(link, &genpd->slave_links, slave_node) { 1210 if (link->slave == new_subdomain && link->master == genpd) { 1211 ret = -EINVAL; 1212 goto out; 1213 } 1214 } 1215 1216 link = kzalloc(sizeof(*link), GFP_KERNEL); 1217 if (!link) { 1218 ret = -ENOMEM; 1219 goto out; 1220 } 1221 link->master = genpd; 1222 list_add_tail(&link->master_node, &genpd->master_links); 1223 link->slave = new_subdomain; 1224 list_add_tail(&link->slave_node, &new_subdomain->slave_links); 1225 if (new_subdomain->status != GPD_STATE_POWER_OFF) 1226 genpd_sd_counter_inc(genpd); 1227 1228 out: 1229 mutex_unlock(&new_subdomain->lock); 1230 genpd_release_lock(genpd); 1231 1232 return ret; 1233} 1234 1235/** 1236 * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain. 1237 * @genpd: Master PM domain to remove the subdomain from. 1238 * @subdomain: Subdomain to be removed. 1239 */ 1240int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd, 1241 struct generic_pm_domain *subdomain) 1242{ 1243 struct gpd_link *link; 1244 int ret = -EINVAL; 1245 1246 if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)) 1247 return -EINVAL; 1248 1249 start: 1250 genpd_acquire_lock(genpd); 1251 1252 list_for_each_entry(link, &genpd->master_links, master_node) { 1253 if (link->slave != subdomain) 1254 continue; 1255 1256 mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING); 1257 1258 if (subdomain->status != GPD_STATE_POWER_OFF 1259 && subdomain->status != GPD_STATE_ACTIVE) { 1260 mutex_unlock(&subdomain->lock); 1261 genpd_release_lock(genpd); 1262 goto start; 1263 } 1264 1265 list_del(&link->master_node); 1266 list_del(&link->slave_node); 1267 kfree(link); 1268 if (subdomain->status != GPD_STATE_POWER_OFF) 1269 genpd_sd_counter_dec(genpd); 1270 1271 mutex_unlock(&subdomain->lock); 1272 1273 ret = 0; 1274 break; 1275 } 1276 1277 genpd_release_lock(genpd); 1278 1279 return ret; 1280} 1281 1282/** 1283 * pm_genpd_init - Initialize a generic I/O PM domain object. 1284 * @genpd: PM domain object to initialize. 1285 * @gov: PM domain governor to associate with the domain (may be NULL). 1286 * @is_off: Initial value of the domain's power_is_off field. 1287 */ 1288void pm_genpd_init(struct generic_pm_domain *genpd, 1289 struct dev_power_governor *gov, bool is_off) 1290{ 1291 if (IS_ERR_OR_NULL(genpd)) 1292 return; 1293 1294 INIT_LIST_HEAD(&genpd->master_links); 1295 INIT_LIST_HEAD(&genpd->slave_links); 1296 INIT_LIST_HEAD(&genpd->dev_list); 1297 mutex_init(&genpd->lock); 1298 genpd->gov = gov; 1299 INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn); 1300 genpd->in_progress = 0; 1301 atomic_set(&genpd->sd_count, 0); 1302 genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE; 1303 init_waitqueue_head(&genpd->status_wait_queue); 1304 genpd->poweroff_task = NULL; 1305 genpd->resume_count = 0; 1306 genpd->device_count = 0; 1307 genpd->suspended_count = 0; 1308 genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend; 1309 genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume; 1310 genpd->domain.ops.runtime_idle = pm_generic_runtime_idle; 1311 genpd->domain.ops.prepare = pm_genpd_prepare; 1312 genpd->domain.ops.suspend = pm_genpd_suspend; 1313 genpd->domain.ops.suspend_noirq = pm_genpd_suspend_noirq; 1314 genpd->domain.ops.resume_noirq = pm_genpd_resume_noirq; 1315 genpd->domain.ops.resume = pm_genpd_resume; 1316 genpd->domain.ops.freeze = pm_genpd_freeze; 1317 genpd->domain.ops.freeze_noirq = pm_genpd_freeze_noirq; 1318 genpd->domain.ops.thaw_noirq = pm_genpd_thaw_noirq; 1319 genpd->domain.ops.thaw = pm_genpd_thaw; 1320 genpd->domain.ops.poweroff = pm_genpd_dev_poweroff; 1321 genpd->domain.ops.poweroff_noirq = pm_genpd_dev_poweroff_noirq; 1322 genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq; 1323 genpd->domain.ops.restore = pm_genpd_restore; 1324 genpd->domain.ops.complete = pm_genpd_complete; 1325 mutex_lock(&gpd_list_lock); 1326 list_add(&genpd->gpd_list_node, &gpd_list); 1327 mutex_unlock(&gpd_list_lock); 1328} 1329