1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Devices PM QoS constraints management 4 * 5 * Copyright (C) 2011 Texas Instruments, Inc. 6 * 7 * This module exposes the interface to kernel space for specifying 8 * per-device PM QoS dependencies. It provides infrastructure for registration 9 * of: 10 * 11 * Dependents on a QoS value : register requests 12 * Watchers of QoS value : get notified when target QoS value changes 13 * 14 * This QoS design is best effort based. Dependents register their QoS needs. 15 * Watchers register to keep track of the current QoS needs of the system. 16 * Watchers can register a per-device notification callback using the 17 * dev_pm_qos_*_notifier API. The notification chain data is stored in the 18 * per-device constraint data struct. 19 * 20 * Note about the per-device constraint data struct allocation: 21 * . The per-device constraints data struct ptr is stored into the device 22 * dev_pm_info. 23 * . To minimize the data usage by the per-device constraints, the data struct 24 * is only allocated at the first call to dev_pm_qos_add_request. 25 * . The data is later free'd when the device is removed from the system. 26 * . A global mutex protects the constraints users from the data being 27 * allocated and free'd. 28 */ 29 30#include <linux/pm_qos.h> 31#include <linux/spinlock.h> 32#include <linux/slab.h> 33#include <linux/device.h> 34#include <linux/mutex.h> 35#include <linux/export.h> 36#include <linux/pm_runtime.h> 37#include <linux/err.h> 38#include <trace/events/power.h> 39 40#include "power.h" 41 42static DEFINE_MUTEX(dev_pm_qos_mtx); 43static DEFINE_MUTEX(dev_pm_qos_sysfs_mtx); 44 45/** 46 * __dev_pm_qos_flags - Check PM QoS flags for a given device. 47 * @dev: Device to check the PM QoS flags for. 48 * @mask: Flags to check against. 49 * 50 * This routine must be called with dev->power.lock held. 51 */ 52enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask) 53{ 54 struct dev_pm_qos *qos = dev->power.qos; 55 struct pm_qos_flags *pqf; 56 s32 val; 57 58 lockdep_assert_held(&dev->power.lock); 59 60 if (IS_ERR_OR_NULL(qos)) 61 return PM_QOS_FLAGS_UNDEFINED; 62 63 pqf = &qos->flags; 64 if (list_empty(&pqf->list)) 65 return PM_QOS_FLAGS_UNDEFINED; 66 67 val = pqf->effective_flags & mask; 68 if (val) 69 return (val == mask) ? PM_QOS_FLAGS_ALL : PM_QOS_FLAGS_SOME; 70 71 return PM_QOS_FLAGS_NONE; 72} 73 74/** 75 * dev_pm_qos_flags - Check PM QoS flags for a given device (locked). 76 * @dev: Device to check the PM QoS flags for. 77 * @mask: Flags to check against. 78 */ 79enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask) 80{ 81 unsigned long irqflags; 82 enum pm_qos_flags_status ret; 83 84 spin_lock_irqsave(&dev->power.lock, irqflags); 85 ret = __dev_pm_qos_flags(dev, mask); 86 spin_unlock_irqrestore(&dev->power.lock, irqflags); 87 88 return ret; 89} 90EXPORT_SYMBOL_GPL(dev_pm_qos_flags); 91 92/** 93 * __dev_pm_qos_resume_latency - Get resume latency constraint for a given device. 94 * @dev: Device to get the PM QoS constraint value for. 95 * 96 * This routine must be called with dev->power.lock held. 97 */ 98s32 __dev_pm_qos_resume_latency(struct device *dev) 99{ 100 lockdep_assert_held(&dev->power.lock); 101 102 return dev_pm_qos_raw_resume_latency(dev); 103} 104 105/** 106 * dev_pm_qos_read_value - Get PM QoS constraint for a given device (locked). 107 * @dev: Device to get the PM QoS constraint value for. 108 * @type: QoS request type. 109 */ 110s32 dev_pm_qos_read_value(struct device *dev, enum dev_pm_qos_req_type type) 111{ 112 struct dev_pm_qos *qos = dev->power.qos; 113 unsigned long flags; 114 s32 ret; 115 116 spin_lock_irqsave(&dev->power.lock, flags); 117 118 switch (type) { 119 case DEV_PM_QOS_RESUME_LATENCY: 120 ret = IS_ERR_OR_NULL(qos) ? PM_QOS_RESUME_LATENCY_NO_CONSTRAINT 121 : pm_qos_read_value(&qos->resume_latency); 122 break; 123 case DEV_PM_QOS_MIN_FREQUENCY: 124 ret = IS_ERR_OR_NULL(qos) ? PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE 125 : freq_qos_read_value(&qos->freq, FREQ_QOS_MIN); 126 break; 127 case DEV_PM_QOS_MAX_FREQUENCY: 128 ret = IS_ERR_OR_NULL(qos) ? PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE 129 : freq_qos_read_value(&qos->freq, FREQ_QOS_MAX); 130 break; 131 default: 132 WARN_ON(1); 133 ret = 0; 134 } 135 136 spin_unlock_irqrestore(&dev->power.lock, flags); 137 138 return ret; 139} 140 141/** 142 * apply_constraint - Add/modify/remove device PM QoS request. 143 * @req: Constraint request to apply 144 * @action: Action to perform (add/update/remove). 145 * @value: Value to assign to the QoS request. 146 * 147 * Internal function to update the constraints list using the PM QoS core 148 * code and if needed call the per-device callbacks. 149 */ 150static int apply_constraint(struct dev_pm_qos_request *req, 151 enum pm_qos_req_action action, s32 value) 152{ 153 struct dev_pm_qos *qos = req->dev->power.qos; 154 int ret; 155 156 switch(req->type) { 157 case DEV_PM_QOS_RESUME_LATENCY: 158 if (WARN_ON(action != PM_QOS_REMOVE_REQ && value < 0)) 159 value = 0; 160 161 ret = pm_qos_update_target(&qos->resume_latency, 162 &req->data.pnode, action, value); 163 break; 164 case DEV_PM_QOS_LATENCY_TOLERANCE: 165 ret = pm_qos_update_target(&qos->latency_tolerance, 166 &req->data.pnode, action, value); 167 if (ret) { 168 value = pm_qos_read_value(&qos->latency_tolerance); 169 req->dev->power.set_latency_tolerance(req->dev, value); 170 } 171 break; 172 case DEV_PM_QOS_MIN_FREQUENCY: 173 case DEV_PM_QOS_MAX_FREQUENCY: 174 ret = freq_qos_apply(&req->data.freq, action, value); 175 break; 176 case DEV_PM_QOS_FLAGS: 177 ret = pm_qos_update_flags(&qos->flags, &req->data.flr, 178 action, value); 179 break; 180 default: 181 ret = -EINVAL; 182 } 183 184 return ret; 185} 186 187/* 188 * dev_pm_qos_constraints_allocate 189 * @dev: device to allocate data for 190 * 191 * Called at the first call to add_request, for constraint data allocation 192 * Must be called with the dev_pm_qos_mtx mutex held 193 */ 194static int dev_pm_qos_constraints_allocate(struct device *dev) 195{ 196 struct dev_pm_qos *qos; 197 struct pm_qos_constraints *c; 198 struct blocking_notifier_head *n; 199 200 qos = kzalloc(sizeof(*qos), GFP_KERNEL); 201 if (!qos) 202 return -ENOMEM; 203 204 n = kcalloc(3, sizeof(*n), GFP_KERNEL); 205 if (!n) { 206 kfree(qos); 207 return -ENOMEM; 208 } 209 210 c = &qos->resume_latency; 211 plist_head_init(&c->list); 212 c->target_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE; 213 c->default_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE; 214 c->no_constraint_value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; 215 c->type = PM_QOS_MIN; 216 c->notifiers = n; 217 BLOCKING_INIT_NOTIFIER_HEAD(n); 218 219 c = &qos->latency_tolerance; 220 plist_head_init(&c->list); 221 c->target_value = PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE; 222 c->default_value = PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE; 223 c->no_constraint_value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT; 224 c->type = PM_QOS_MIN; 225 226 freq_constraints_init(&qos->freq); 227 228 INIT_LIST_HEAD(&qos->flags.list); 229 230 spin_lock_irq(&dev->power.lock); 231 dev->power.qos = qos; 232 spin_unlock_irq(&dev->power.lock); 233 234 return 0; 235} 236 237static void __dev_pm_qos_hide_latency_limit(struct device *dev); 238static void __dev_pm_qos_hide_flags(struct device *dev); 239 240/** 241 * dev_pm_qos_constraints_destroy 242 * @dev: target device 243 * 244 * Called from the device PM subsystem on device removal under device_pm_lock(). 245 */ 246void dev_pm_qos_constraints_destroy(struct device *dev) 247{ 248 struct dev_pm_qos *qos; 249 struct dev_pm_qos_request *req, *tmp; 250 struct pm_qos_constraints *c; 251 struct pm_qos_flags *f; 252 253 mutex_lock(&dev_pm_qos_sysfs_mtx); 254 255 /* 256 * If the device's PM QoS resume latency limit or PM QoS flags have been 257 * exposed to user space, they have to be hidden at this point. 258 */ 259 pm_qos_sysfs_remove_resume_latency(dev); 260 pm_qos_sysfs_remove_flags(dev); 261 262 mutex_lock(&dev_pm_qos_mtx); 263 264 __dev_pm_qos_hide_latency_limit(dev); 265 __dev_pm_qos_hide_flags(dev); 266 267 qos = dev->power.qos; 268 if (!qos) 269 goto out; 270 271 /* Flush the constraints lists for the device. */ 272 c = &qos->resume_latency; 273 plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) { 274 /* 275 * Update constraints list and call the notification 276 * callbacks if needed 277 */ 278 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); 279 memset(req, 0, sizeof(*req)); 280 } 281 282 c = &qos->latency_tolerance; 283 plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) { 284 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); 285 memset(req, 0, sizeof(*req)); 286 } 287 288 c = &qos->freq.min_freq; 289 plist_for_each_entry_safe(req, tmp, &c->list, data.freq.pnode) { 290 apply_constraint(req, PM_QOS_REMOVE_REQ, 291 PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE); 292 memset(req, 0, sizeof(*req)); 293 } 294 295 c = &qos->freq.max_freq; 296 plist_for_each_entry_safe(req, tmp, &c->list, data.freq.pnode) { 297 apply_constraint(req, PM_QOS_REMOVE_REQ, 298 PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE); 299 memset(req, 0, sizeof(*req)); 300 } 301 302 f = &qos->flags; 303 list_for_each_entry_safe(req, tmp, &f->list, data.flr.node) { 304 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); 305 memset(req, 0, sizeof(*req)); 306 } 307 308 spin_lock_irq(&dev->power.lock); 309 dev->power.qos = ERR_PTR(-ENODEV); 310 spin_unlock_irq(&dev->power.lock); 311 312 kfree(qos->resume_latency.notifiers); 313 kfree(qos); 314 315 out: 316 mutex_unlock(&dev_pm_qos_mtx); 317 318 mutex_unlock(&dev_pm_qos_sysfs_mtx); 319} 320 321static bool dev_pm_qos_invalid_req_type(struct device *dev, 322 enum dev_pm_qos_req_type type) 323{ 324 return type == DEV_PM_QOS_LATENCY_TOLERANCE && 325 !dev->power.set_latency_tolerance; 326} 327 328static int __dev_pm_qos_add_request(struct device *dev, 329 struct dev_pm_qos_request *req, 330 enum dev_pm_qos_req_type type, s32 value) 331{ 332 int ret = 0; 333 334 if (!dev || !req || dev_pm_qos_invalid_req_type(dev, type)) 335 return -EINVAL; 336 337 if (WARN(dev_pm_qos_request_active(req), 338 "%s() called for already added request\n", __func__)) 339 return -EINVAL; 340 341 if (IS_ERR(dev->power.qos)) 342 ret = -ENODEV; 343 else if (!dev->power.qos) 344 ret = dev_pm_qos_constraints_allocate(dev); 345 346 trace_dev_pm_qos_add_request(dev_name(dev), type, value); 347 if (ret) 348 return ret; 349 350 req->dev = dev; 351 req->type = type; 352 if (req->type == DEV_PM_QOS_MIN_FREQUENCY) 353 ret = freq_qos_add_request(&dev->power.qos->freq, 354 &req->data.freq, 355 FREQ_QOS_MIN, value); 356 else if (req->type == DEV_PM_QOS_MAX_FREQUENCY) 357 ret = freq_qos_add_request(&dev->power.qos->freq, 358 &req->data.freq, 359 FREQ_QOS_MAX, value); 360 else 361 ret = apply_constraint(req, PM_QOS_ADD_REQ, value); 362 363 return ret; 364} 365 366/** 367 * dev_pm_qos_add_request - inserts new qos request into the list 368 * @dev: target device for the constraint 369 * @req: pointer to a preallocated handle 370 * @type: type of the request 371 * @value: defines the qos request 372 * 373 * This function inserts a new entry in the device constraints list of 374 * requested qos performance characteristics. It recomputes the aggregate 375 * QoS expectations of parameters and initializes the dev_pm_qos_request 376 * handle. Caller needs to save this handle for later use in updates and 377 * removal. 378 * 379 * Returns 1 if the aggregated constraint value has changed, 380 * 0 if the aggregated constraint value has not changed, 381 * -EINVAL in case of wrong parameters, -ENOMEM if there's not enough memory 382 * to allocate for data structures, -ENODEV if the device has just been removed 383 * from the system. 384 * 385 * Callers should ensure that the target device is not RPM_SUSPENDED before 386 * using this function for requests of type DEV_PM_QOS_FLAGS. 387 */ 388int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, 389 enum dev_pm_qos_req_type type, s32 value) 390{ 391 int ret; 392 393 mutex_lock(&dev_pm_qos_mtx); 394 ret = __dev_pm_qos_add_request(dev, req, type, value); 395 mutex_unlock(&dev_pm_qos_mtx); 396 return ret; 397} 398EXPORT_SYMBOL_GPL(dev_pm_qos_add_request); 399 400/** 401 * __dev_pm_qos_update_request - Modify an existing device PM QoS request. 402 * @req : PM QoS request to modify. 403 * @new_value: New value to request. 404 */ 405static int __dev_pm_qos_update_request(struct dev_pm_qos_request *req, 406 s32 new_value) 407{ 408 s32 curr_value; 409 int ret = 0; 410 411 if (!req) /*guard against callers passing in null */ 412 return -EINVAL; 413 414 if (WARN(!dev_pm_qos_request_active(req), 415 "%s() called for unknown object\n", __func__)) 416 return -EINVAL; 417 418 if (IS_ERR_OR_NULL(req->dev->power.qos)) 419 return -ENODEV; 420 421 switch(req->type) { 422 case DEV_PM_QOS_RESUME_LATENCY: 423 case DEV_PM_QOS_LATENCY_TOLERANCE: 424 curr_value = req->data.pnode.prio; 425 break; 426 case DEV_PM_QOS_MIN_FREQUENCY: 427 case DEV_PM_QOS_MAX_FREQUENCY: 428 curr_value = req->data.freq.pnode.prio; 429 break; 430 case DEV_PM_QOS_FLAGS: 431 curr_value = req->data.flr.flags; 432 break; 433 default: 434 return -EINVAL; 435 } 436 437 trace_dev_pm_qos_update_request(dev_name(req->dev), req->type, 438 new_value); 439 if (curr_value != new_value) 440 ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value); 441 442 return ret; 443} 444 445/** 446 * dev_pm_qos_update_request - modifies an existing qos request 447 * @req : handle to list element holding a dev_pm_qos request to use 448 * @new_value: defines the qos request 449 * 450 * Updates an existing dev PM qos request along with updating the 451 * target value. 452 * 453 * Attempts are made to make this code callable on hot code paths. 454 * 455 * Returns 1 if the aggregated constraint value has changed, 456 * 0 if the aggregated constraint value has not changed, 457 * -EINVAL in case of wrong parameters, -ENODEV if the device has been 458 * removed from the system 459 * 460 * Callers should ensure that the target device is not RPM_SUSPENDED before 461 * using this function for requests of type DEV_PM_QOS_FLAGS. 462 */ 463int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value) 464{ 465 int ret; 466 467 mutex_lock(&dev_pm_qos_mtx); 468 ret = __dev_pm_qos_update_request(req, new_value); 469 mutex_unlock(&dev_pm_qos_mtx); 470 return ret; 471} 472EXPORT_SYMBOL_GPL(dev_pm_qos_update_request); 473 474static int __dev_pm_qos_remove_request(struct dev_pm_qos_request *req) 475{ 476 int ret; 477 478 if (!req) /*guard against callers passing in null */ 479 return -EINVAL; 480 481 if (WARN(!dev_pm_qos_request_active(req), 482 "%s() called for unknown object\n", __func__)) 483 return -EINVAL; 484 485 if (IS_ERR_OR_NULL(req->dev->power.qos)) 486 return -ENODEV; 487 488 trace_dev_pm_qos_remove_request(dev_name(req->dev), req->type, 489 PM_QOS_DEFAULT_VALUE); 490 ret = apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); 491 memset(req, 0, sizeof(*req)); 492 return ret; 493} 494 495/** 496 * dev_pm_qos_remove_request - modifies an existing qos request 497 * @req: handle to request list element 498 * 499 * Will remove pm qos request from the list of constraints and 500 * recompute the current target value. Call this on slow code paths. 501 * 502 * Returns 1 if the aggregated constraint value has changed, 503 * 0 if the aggregated constraint value has not changed, 504 * -EINVAL in case of wrong parameters, -ENODEV if the device has been 505 * removed from the system 506 * 507 * Callers should ensure that the target device is not RPM_SUSPENDED before 508 * using this function for requests of type DEV_PM_QOS_FLAGS. 509 */ 510int dev_pm_qos_remove_request(struct dev_pm_qos_request *req) 511{ 512 int ret; 513 514 mutex_lock(&dev_pm_qos_mtx); 515 ret = __dev_pm_qos_remove_request(req); 516 mutex_unlock(&dev_pm_qos_mtx); 517 return ret; 518} 519EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request); 520 521/** 522 * dev_pm_qos_add_notifier - sets notification entry for changes to target value 523 * of per-device PM QoS constraints 524 * 525 * @dev: target device for the constraint 526 * @notifier: notifier block managed by caller. 527 * @type: request type. 528 * 529 * Will register the notifier into a notification chain that gets called 530 * upon changes to the target value for the device. 531 * 532 * If the device's constraints object doesn't exist when this routine is called, 533 * it will be created (or error code will be returned if that fails). 534 */ 535int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier, 536 enum dev_pm_qos_req_type type) 537{ 538 int ret = 0; 539 540 mutex_lock(&dev_pm_qos_mtx); 541 542 if (IS_ERR(dev->power.qos)) 543 ret = -ENODEV; 544 else if (!dev->power.qos) 545 ret = dev_pm_qos_constraints_allocate(dev); 546 547 if (ret) 548 goto unlock; 549 550 switch (type) { 551 case DEV_PM_QOS_RESUME_LATENCY: 552 ret = blocking_notifier_chain_register(dev->power.qos->resume_latency.notifiers, 553 notifier); 554 break; 555 case DEV_PM_QOS_MIN_FREQUENCY: 556 ret = freq_qos_add_notifier(&dev->power.qos->freq, 557 FREQ_QOS_MIN, notifier); 558 break; 559 case DEV_PM_QOS_MAX_FREQUENCY: 560 ret = freq_qos_add_notifier(&dev->power.qos->freq, 561 FREQ_QOS_MAX, notifier); 562 break; 563 default: 564 WARN_ON(1); 565 ret = -EINVAL; 566 } 567 568unlock: 569 mutex_unlock(&dev_pm_qos_mtx); 570 return ret; 571} 572EXPORT_SYMBOL_GPL(dev_pm_qos_add_notifier); 573 574/** 575 * dev_pm_qos_remove_notifier - deletes notification for changes to target value 576 * of per-device PM QoS constraints 577 * 578 * @dev: target device for the constraint 579 * @notifier: notifier block to be removed. 580 * @type: request type. 581 * 582 * Will remove the notifier from the notification chain that gets called 583 * upon changes to the target value. 584 */ 585int dev_pm_qos_remove_notifier(struct device *dev, 586 struct notifier_block *notifier, 587 enum dev_pm_qos_req_type type) 588{ 589 int ret = 0; 590 591 mutex_lock(&dev_pm_qos_mtx); 592 593 /* Silently return if the constraints object is not present. */ 594 if (IS_ERR_OR_NULL(dev->power.qos)) 595 goto unlock; 596 597 switch (type) { 598 case DEV_PM_QOS_RESUME_LATENCY: 599 ret = blocking_notifier_chain_unregister(dev->power.qos->resume_latency.notifiers, 600 notifier); 601 break; 602 case DEV_PM_QOS_MIN_FREQUENCY: 603 ret = freq_qos_remove_notifier(&dev->power.qos->freq, 604 FREQ_QOS_MIN, notifier); 605 break; 606 case DEV_PM_QOS_MAX_FREQUENCY: 607 ret = freq_qos_remove_notifier(&dev->power.qos->freq, 608 FREQ_QOS_MAX, notifier); 609 break; 610 default: 611 WARN_ON(1); 612 ret = -EINVAL; 613 } 614 615unlock: 616 mutex_unlock(&dev_pm_qos_mtx); 617 return ret; 618} 619EXPORT_SYMBOL_GPL(dev_pm_qos_remove_notifier); 620 621/** 622 * dev_pm_qos_add_ancestor_request - Add PM QoS request for device's ancestor. 623 * @dev: Device whose ancestor to add the request for. 624 * @req: Pointer to the preallocated handle. 625 * @type: Type of the request. 626 * @value: Constraint latency value. 627 */ 628int dev_pm_qos_add_ancestor_request(struct device *dev, 629 struct dev_pm_qos_request *req, 630 enum dev_pm_qos_req_type type, s32 value) 631{ 632 struct device *ancestor = dev->parent; 633 int ret = -ENODEV; 634 635 switch (type) { 636 case DEV_PM_QOS_RESUME_LATENCY: 637 while (ancestor && !ancestor->power.ignore_children) 638 ancestor = ancestor->parent; 639 640 break; 641 case DEV_PM_QOS_LATENCY_TOLERANCE: 642 while (ancestor && !ancestor->power.set_latency_tolerance) 643 ancestor = ancestor->parent; 644 645 break; 646 default: 647 ancestor = NULL; 648 } 649 if (ancestor) 650 ret = dev_pm_qos_add_request(ancestor, req, type, value); 651 652 if (ret < 0) 653 req->dev = NULL; 654 655 return ret; 656} 657EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request); 658 659static void __dev_pm_qos_drop_user_request(struct device *dev, 660 enum dev_pm_qos_req_type type) 661{ 662 struct dev_pm_qos_request *req = NULL; 663 664 switch(type) { 665 case DEV_PM_QOS_RESUME_LATENCY: 666 req = dev->power.qos->resume_latency_req; 667 dev->power.qos->resume_latency_req = NULL; 668 break; 669 case DEV_PM_QOS_LATENCY_TOLERANCE: 670 req = dev->power.qos->latency_tolerance_req; 671 dev->power.qos->latency_tolerance_req = NULL; 672 break; 673 case DEV_PM_QOS_FLAGS: 674 req = dev->power.qos->flags_req; 675 dev->power.qos->flags_req = NULL; 676 break; 677 default: 678 WARN_ON(1); 679 return; 680 } 681 __dev_pm_qos_remove_request(req); 682 kfree(req); 683} 684 685static void dev_pm_qos_drop_user_request(struct device *dev, 686 enum dev_pm_qos_req_type type) 687{ 688 mutex_lock(&dev_pm_qos_mtx); 689 __dev_pm_qos_drop_user_request(dev, type); 690 mutex_unlock(&dev_pm_qos_mtx); 691} 692 693/** 694 * dev_pm_qos_expose_latency_limit - Expose PM QoS latency limit to user space. 695 * @dev: Device whose PM QoS latency limit is to be exposed to user space. 696 * @value: Initial value of the latency limit. 697 */ 698int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value) 699{ 700 struct dev_pm_qos_request *req; 701 int ret; 702 703 if (!device_is_registered(dev) || value < 0) 704 return -EINVAL; 705 706 req = kzalloc(sizeof(*req), GFP_KERNEL); 707 if (!req) 708 return -ENOMEM; 709 710 ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_RESUME_LATENCY, value); 711 if (ret < 0) { 712 kfree(req); 713 return ret; 714 } 715 716 mutex_lock(&dev_pm_qos_sysfs_mtx); 717 718 mutex_lock(&dev_pm_qos_mtx); 719 720 if (IS_ERR_OR_NULL(dev->power.qos)) 721 ret = -ENODEV; 722 else if (dev->power.qos->resume_latency_req) 723 ret = -EEXIST; 724 725 if (ret < 0) { 726 __dev_pm_qos_remove_request(req); 727 kfree(req); 728 mutex_unlock(&dev_pm_qos_mtx); 729 goto out; 730 } 731 dev->power.qos->resume_latency_req = req; 732 733 mutex_unlock(&dev_pm_qos_mtx); 734 735 ret = pm_qos_sysfs_add_resume_latency(dev); 736 if (ret) 737 dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_RESUME_LATENCY); 738 739 out: 740 mutex_unlock(&dev_pm_qos_sysfs_mtx); 741 return ret; 742} 743EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_limit); 744 745static void __dev_pm_qos_hide_latency_limit(struct device *dev) 746{ 747 if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->resume_latency_req) 748 __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_RESUME_LATENCY); 749} 750 751/** 752 * dev_pm_qos_hide_latency_limit - Hide PM QoS latency limit from user space. 753 * @dev: Device whose PM QoS latency limit is to be hidden from user space. 754 */ 755void dev_pm_qos_hide_latency_limit(struct device *dev) 756{ 757 mutex_lock(&dev_pm_qos_sysfs_mtx); 758 759 pm_qos_sysfs_remove_resume_latency(dev); 760 761 mutex_lock(&dev_pm_qos_mtx); 762 __dev_pm_qos_hide_latency_limit(dev); 763 mutex_unlock(&dev_pm_qos_mtx); 764 765 mutex_unlock(&dev_pm_qos_sysfs_mtx); 766} 767EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_limit); 768 769/** 770 * dev_pm_qos_expose_flags - Expose PM QoS flags of a device to user space. 771 * @dev: Device whose PM QoS flags are to be exposed to user space. 772 * @val: Initial values of the flags. 773 */ 774int dev_pm_qos_expose_flags(struct device *dev, s32 val) 775{ 776 struct dev_pm_qos_request *req; 777 int ret; 778 779 if (!device_is_registered(dev)) 780 return -EINVAL; 781 782 req = kzalloc(sizeof(*req), GFP_KERNEL); 783 if (!req) 784 return -ENOMEM; 785 786 ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_FLAGS, val); 787 if (ret < 0) { 788 kfree(req); 789 return ret; 790 } 791 792 pm_runtime_get_sync(dev); 793 mutex_lock(&dev_pm_qos_sysfs_mtx); 794 795 mutex_lock(&dev_pm_qos_mtx); 796 797 if (IS_ERR_OR_NULL(dev->power.qos)) 798 ret = -ENODEV; 799 else if (dev->power.qos->flags_req) 800 ret = -EEXIST; 801 802 if (ret < 0) { 803 __dev_pm_qos_remove_request(req); 804 kfree(req); 805 mutex_unlock(&dev_pm_qos_mtx); 806 goto out; 807 } 808 dev->power.qos->flags_req = req; 809 810 mutex_unlock(&dev_pm_qos_mtx); 811 812 ret = pm_qos_sysfs_add_flags(dev); 813 if (ret) 814 dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS); 815 816 out: 817 mutex_unlock(&dev_pm_qos_sysfs_mtx); 818 pm_runtime_put(dev); 819 return ret; 820} 821EXPORT_SYMBOL_GPL(dev_pm_qos_expose_flags); 822 823static void __dev_pm_qos_hide_flags(struct device *dev) 824{ 825 if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->flags_req) 826 __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS); 827} 828 829/** 830 * dev_pm_qos_hide_flags - Hide PM QoS flags of a device from user space. 831 * @dev: Device whose PM QoS flags are to be hidden from user space. 832 */ 833void dev_pm_qos_hide_flags(struct device *dev) 834{ 835 pm_runtime_get_sync(dev); 836 mutex_lock(&dev_pm_qos_sysfs_mtx); 837 838 pm_qos_sysfs_remove_flags(dev); 839 840 mutex_lock(&dev_pm_qos_mtx); 841 __dev_pm_qos_hide_flags(dev); 842 mutex_unlock(&dev_pm_qos_mtx); 843 844 mutex_unlock(&dev_pm_qos_sysfs_mtx); 845 pm_runtime_put(dev); 846} 847EXPORT_SYMBOL_GPL(dev_pm_qos_hide_flags); 848 849/** 850 * dev_pm_qos_update_flags - Update PM QoS flags request owned by user space. 851 * @dev: Device to update the PM QoS flags request for. 852 * @mask: Flags to set/clear. 853 * @set: Whether to set or clear the flags (true means set). 854 */ 855int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set) 856{ 857 s32 value; 858 int ret; 859 860 pm_runtime_get_sync(dev); 861 mutex_lock(&dev_pm_qos_mtx); 862 863 if (IS_ERR_OR_NULL(dev->power.qos) || !dev->power.qos->flags_req) { 864 ret = -EINVAL; 865 goto out; 866 } 867 868 value = dev_pm_qos_requested_flags(dev); 869 if (set) 870 value |= mask; 871 else 872 value &= ~mask; 873 874 ret = __dev_pm_qos_update_request(dev->power.qos->flags_req, value); 875 876 out: 877 mutex_unlock(&dev_pm_qos_mtx); 878 pm_runtime_put(dev); 879 return ret; 880} 881 882/** 883 * dev_pm_qos_get_user_latency_tolerance - Get user space latency tolerance. 884 * @dev: Device to obtain the user space latency tolerance for. 885 */ 886s32 dev_pm_qos_get_user_latency_tolerance(struct device *dev) 887{ 888 s32 ret; 889 890 mutex_lock(&dev_pm_qos_mtx); 891 ret = IS_ERR_OR_NULL(dev->power.qos) 892 || !dev->power.qos->latency_tolerance_req ? 893 PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT : 894 dev->power.qos->latency_tolerance_req->data.pnode.prio; 895 mutex_unlock(&dev_pm_qos_mtx); 896 return ret; 897} 898 899/** 900 * dev_pm_qos_update_user_latency_tolerance - Update user space latency tolerance. 901 * @dev: Device to update the user space latency tolerance for. 902 * @val: New user space latency tolerance for @dev (negative values disable). 903 */ 904int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val) 905{ 906 int ret; 907 908 mutex_lock(&dev_pm_qos_mtx); 909 910 if (IS_ERR_OR_NULL(dev->power.qos) 911 || !dev->power.qos->latency_tolerance_req) { 912 struct dev_pm_qos_request *req; 913 914 if (val < 0) { 915 if (val == PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT) 916 ret = 0; 917 else 918 ret = -EINVAL; 919 goto out; 920 } 921 req = kzalloc(sizeof(*req), GFP_KERNEL); 922 if (!req) { 923 ret = -ENOMEM; 924 goto out; 925 } 926 ret = __dev_pm_qos_add_request(dev, req, DEV_PM_QOS_LATENCY_TOLERANCE, val); 927 if (ret < 0) { 928 kfree(req); 929 goto out; 930 } 931 dev->power.qos->latency_tolerance_req = req; 932 } else { 933 if (val < 0) { 934 __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY_TOLERANCE); 935 ret = 0; 936 } else { 937 ret = __dev_pm_qos_update_request(dev->power.qos->latency_tolerance_req, val); 938 } 939 } 940 941 out: 942 mutex_unlock(&dev_pm_qos_mtx); 943 return ret; 944} 945EXPORT_SYMBOL_GPL(dev_pm_qos_update_user_latency_tolerance); 946 947/** 948 * dev_pm_qos_expose_latency_tolerance - Expose latency tolerance to userspace 949 * @dev: Device whose latency tolerance to expose 950 */ 951int dev_pm_qos_expose_latency_tolerance(struct device *dev) 952{ 953 int ret; 954 955 if (!dev->power.set_latency_tolerance) 956 return -EINVAL; 957 958 mutex_lock(&dev_pm_qos_sysfs_mtx); 959 ret = pm_qos_sysfs_add_latency_tolerance(dev); 960 mutex_unlock(&dev_pm_qos_sysfs_mtx); 961 962 return ret; 963} 964EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_tolerance); 965 966/** 967 * dev_pm_qos_hide_latency_tolerance - Hide latency tolerance from userspace 968 * @dev: Device whose latency tolerance to hide 969 */ 970void dev_pm_qos_hide_latency_tolerance(struct device *dev) 971{ 972 mutex_lock(&dev_pm_qos_sysfs_mtx); 973 pm_qos_sysfs_remove_latency_tolerance(dev); 974 mutex_unlock(&dev_pm_qos_sysfs_mtx); 975 976 /* Remove the request from user space now */ 977 pm_runtime_get_sync(dev); 978 dev_pm_qos_update_user_latency_tolerance(dev, 979 PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT); 980 pm_runtime_put(dev); 981} 982EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_tolerance); 983