1 /* 2 * Devices PM QoS constraints management 3 * 4 * Copyright (C) 2011 Texas Instruments, Inc. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * 11 * This module exposes the interface to kernel space for specifying 12 * per-device PM QoS dependencies. It provides infrastructure for registration 13 * of: 14 * 15 * Dependents on a QoS value : register requests 16 * Watchers of QoS value : get notified when target QoS value changes 17 * 18 * This QoS design is best effort based. Dependents register their QoS needs. 19 * Watchers register to keep track of the current QoS needs of the system. 20 * Watchers can register different types of notification callbacks: 21 * . a per-device notification callback using the dev_pm_qos_*_notifier API. 22 * The notification chain data is stored in the per-device constraint 23 * data struct. 24 * . a system-wide notification callback using the dev_pm_qos_*_global_notifier 25 * API. The notification chain data is stored in a static variable. 26 * 27 * Note about the per-device constraint data struct allocation: 28 * . The per-device constraints data struct ptr is tored into the device 29 * dev_pm_info. 30 * . To minimize the data usage by the per-device constraints, the data struct 31 * is only allocated at the first call to dev_pm_qos_add_request. 32 * . The data is later free'd when the device is removed from the system. 33 * . A global mutex protects the constraints users from the data being 34 * allocated and free'd. 35 */ 36 37 #include <linux/pm_qos.h> 38 #include <linux/spinlock.h> 39 #include <linux/slab.h> 40 #include <linux/device.h> 41 #include <linux/mutex.h> 42 #include <linux/export.h> 43 #include <linux/pm_runtime.h> 44 #include <linux/err.h> 45 46 #include "power.h" 47 48 static DEFINE_MUTEX(dev_pm_qos_mtx); 49 static DEFINE_MUTEX(dev_pm_qos_sysfs_mtx); 50 51 static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers); 52 53 /** 54 * __dev_pm_qos_flags - Check PM QoS flags for a given device. 55 * @dev: Device to check the PM QoS flags for. 56 * @mask: Flags to check against. 57 * 58 * This routine must be called with dev->power.lock held. 59 */ 60 enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask) 61 { 62 struct dev_pm_qos *qos = dev->power.qos; 63 struct pm_qos_flags *pqf; 64 s32 val; 65 66 if (IS_ERR_OR_NULL(qos)) 67 return PM_QOS_FLAGS_UNDEFINED; 68 69 pqf = &qos->flags; 70 if (list_empty(&pqf->list)) 71 return PM_QOS_FLAGS_UNDEFINED; 72 73 val = pqf->effective_flags & mask; 74 if (val) 75 return (val == mask) ? PM_QOS_FLAGS_ALL : PM_QOS_FLAGS_SOME; 76 77 return PM_QOS_FLAGS_NONE; 78 } 79 80 /** 81 * dev_pm_qos_flags - Check PM QoS flags for a given device (locked). 82 * @dev: Device to check the PM QoS flags for. 83 * @mask: Flags to check against. 84 */ 85 enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask) 86 { 87 unsigned long irqflags; 88 enum pm_qos_flags_status ret; 89 90 spin_lock_irqsave(&dev->power.lock, irqflags); 91 ret = __dev_pm_qos_flags(dev, mask); 92 spin_unlock_irqrestore(&dev->power.lock, irqflags); 93 94 return ret; 95 } 96 EXPORT_SYMBOL_GPL(dev_pm_qos_flags); 97 98 /** 99 * __dev_pm_qos_read_value - Get PM QoS constraint for a given device. 100 * @dev: Device to get the PM QoS constraint value for. 101 * 102 * This routine must be called with dev->power.lock held. 103 */ 104 s32 __dev_pm_qos_read_value(struct device *dev) 105 { 106 return IS_ERR_OR_NULL(dev->power.qos) ? 107 0 : pm_qos_read_value(&dev->power.qos->latency); 108 } 109 110 /** 111 * dev_pm_qos_read_value - Get PM QoS constraint for a given device (locked). 112 * @dev: Device to get the PM QoS constraint value for. 113 */ 114 s32 dev_pm_qos_read_value(struct device *dev) 115 { 116 unsigned long flags; 117 s32 ret; 118 119 spin_lock_irqsave(&dev->power.lock, flags); 120 ret = __dev_pm_qos_read_value(dev); 121 spin_unlock_irqrestore(&dev->power.lock, flags); 122 123 return ret; 124 } 125 126 /** 127 * apply_constraint - Add/modify/remove device PM QoS request. 128 * @req: Constraint request to apply 129 * @action: Action to perform (add/update/remove). 130 * @value: Value to assign to the QoS request. 131 * 132 * Internal function to update the constraints list using the PM QoS core 133 * code and if needed call the per-device and the global notification 134 * callbacks 135 */ 136 static int apply_constraint(struct dev_pm_qos_request *req, 137 enum pm_qos_req_action action, s32 value) 138 { 139 struct dev_pm_qos *qos = req->dev->power.qos; 140 int ret; 141 142 switch(req->type) { 143 case DEV_PM_QOS_LATENCY: 144 ret = pm_qos_update_target(&qos->latency, &req->data.pnode, 145 action, value); 146 if (ret) { 147 value = pm_qos_read_value(&qos->latency); 148 blocking_notifier_call_chain(&dev_pm_notifiers, 149 (unsigned long)value, 150 req); 151 } 152 break; 153 case DEV_PM_QOS_FLAGS: 154 ret = pm_qos_update_flags(&qos->flags, &req->data.flr, 155 action, value); 156 break; 157 default: 158 ret = -EINVAL; 159 } 160 161 return ret; 162 } 163 164 /* 165 * dev_pm_qos_constraints_allocate 166 * @dev: device to allocate data for 167 * 168 * Called at the first call to add_request, for constraint data allocation 169 * Must be called with the dev_pm_qos_mtx mutex held 170 */ 171 static int dev_pm_qos_constraints_allocate(struct device *dev) 172 { 173 struct dev_pm_qos *qos; 174 struct pm_qos_constraints *c; 175 struct blocking_notifier_head *n; 176 177 qos = kzalloc(sizeof(*qos), GFP_KERNEL); 178 if (!qos) 179 return -ENOMEM; 180 181 n = kzalloc(sizeof(*n), GFP_KERNEL); 182 if (!n) { 183 kfree(qos); 184 return -ENOMEM; 185 } 186 BLOCKING_INIT_NOTIFIER_HEAD(n); 187 188 c = &qos->latency; 189 plist_head_init(&c->list); 190 c->target_value = PM_QOS_DEV_LAT_DEFAULT_VALUE; 191 c->default_value = PM_QOS_DEV_LAT_DEFAULT_VALUE; 192 c->type = PM_QOS_MIN; 193 c->notifiers = n; 194 195 INIT_LIST_HEAD(&qos->flags.list); 196 197 spin_lock_irq(&dev->power.lock); 198 dev->power.qos = qos; 199 spin_unlock_irq(&dev->power.lock); 200 201 return 0; 202 } 203 204 static void __dev_pm_qos_hide_latency_limit(struct device *dev); 205 static void __dev_pm_qos_hide_flags(struct device *dev); 206 207 /** 208 * dev_pm_qos_constraints_destroy 209 * @dev: target device 210 * 211 * Called from the device PM subsystem on device removal under device_pm_lock(). 212 */ 213 void dev_pm_qos_constraints_destroy(struct device *dev) 214 { 215 struct dev_pm_qos *qos; 216 struct dev_pm_qos_request *req, *tmp; 217 struct pm_qos_constraints *c; 218 struct pm_qos_flags *f; 219 220 mutex_lock(&dev_pm_qos_sysfs_mtx); 221 222 /* 223 * If the device's PM QoS resume latency limit or PM QoS flags have been 224 * exposed to user space, they have to be hidden at this point. 225 */ 226 pm_qos_sysfs_remove_latency(dev); 227 pm_qos_sysfs_remove_flags(dev); 228 229 mutex_lock(&dev_pm_qos_mtx); 230 231 __dev_pm_qos_hide_latency_limit(dev); 232 __dev_pm_qos_hide_flags(dev); 233 234 qos = dev->power.qos; 235 if (!qos) 236 goto out; 237 238 /* Flush the constraints lists for the device. */ 239 c = &qos->latency; 240 plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) { 241 /* 242 * Update constraints list and call the notification 243 * callbacks if needed 244 */ 245 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); 246 memset(req, 0, sizeof(*req)); 247 } 248 f = &qos->flags; 249 list_for_each_entry_safe(req, tmp, &f->list, data.flr.node) { 250 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); 251 memset(req, 0, sizeof(*req)); 252 } 253 254 spin_lock_irq(&dev->power.lock); 255 dev->power.qos = ERR_PTR(-ENODEV); 256 spin_unlock_irq(&dev->power.lock); 257 258 kfree(c->notifiers); 259 kfree(qos); 260 261 out: 262 mutex_unlock(&dev_pm_qos_mtx); 263 264 mutex_unlock(&dev_pm_qos_sysfs_mtx); 265 } 266 267 /** 268 * dev_pm_qos_add_request - inserts new qos request into the list 269 * @dev: target device for the constraint 270 * @req: pointer to a preallocated handle 271 * @type: type of the request 272 * @value: defines the qos request 273 * 274 * This function inserts a new entry in the device constraints list of 275 * requested qos performance characteristics. It recomputes the aggregate 276 * QoS expectations of parameters and initializes the dev_pm_qos_request 277 * handle. Caller needs to save this handle for later use in updates and 278 * removal. 279 * 280 * Returns 1 if the aggregated constraint value has changed, 281 * 0 if the aggregated constraint value has not changed, 282 * -EINVAL in case of wrong parameters, -ENOMEM if there's not enough memory 283 * to allocate for data structures, -ENODEV if the device has just been removed 284 * from the system. 285 * 286 * Callers should ensure that the target device is not RPM_SUSPENDED before 287 * using this function for requests of type DEV_PM_QOS_FLAGS. 288 */ 289 int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, 290 enum dev_pm_qos_req_type type, s32 value) 291 { 292 int ret = 0; 293 294 if (!dev || !req) /*guard against callers passing in null */ 295 return -EINVAL; 296 297 if (WARN(dev_pm_qos_request_active(req), 298 "%s() called for already added request\n", __func__)) 299 return -EINVAL; 300 301 mutex_lock(&dev_pm_qos_mtx); 302 303 if (IS_ERR(dev->power.qos)) 304 ret = -ENODEV; 305 else if (!dev->power.qos) 306 ret = dev_pm_qos_constraints_allocate(dev); 307 308 if (!ret) { 309 req->dev = dev; 310 req->type = type; 311 ret = apply_constraint(req, PM_QOS_ADD_REQ, value); 312 } 313 314 mutex_unlock(&dev_pm_qos_mtx); 315 316 return ret; 317 } 318 EXPORT_SYMBOL_GPL(dev_pm_qos_add_request); 319 320 /** 321 * __dev_pm_qos_update_request - Modify an existing device PM QoS request. 322 * @req : PM QoS request to modify. 323 * @new_value: New value to request. 324 */ 325 static int __dev_pm_qos_update_request(struct dev_pm_qos_request *req, 326 s32 new_value) 327 { 328 s32 curr_value; 329 int ret = 0; 330 331 if (!req) /*guard against callers passing in null */ 332 return -EINVAL; 333 334 if (WARN(!dev_pm_qos_request_active(req), 335 "%s() called for unknown object\n", __func__)) 336 return -EINVAL; 337 338 if (IS_ERR_OR_NULL(req->dev->power.qos)) 339 return -ENODEV; 340 341 switch(req->type) { 342 case DEV_PM_QOS_LATENCY: 343 curr_value = req->data.pnode.prio; 344 break; 345 case DEV_PM_QOS_FLAGS: 346 curr_value = req->data.flr.flags; 347 break; 348 default: 349 return -EINVAL; 350 } 351 352 if (curr_value != new_value) 353 ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value); 354 355 return ret; 356 } 357 358 /** 359 * dev_pm_qos_update_request - modifies an existing qos request 360 * @req : handle to list element holding a dev_pm_qos request to use 361 * @new_value: defines the qos request 362 * 363 * Updates an existing dev PM qos request along with updating the 364 * target value. 365 * 366 * Attempts are made to make this code callable on hot code paths. 367 * 368 * Returns 1 if the aggregated constraint value has changed, 369 * 0 if the aggregated constraint value has not changed, 370 * -EINVAL in case of wrong parameters, -ENODEV if the device has been 371 * removed from the system 372 * 373 * Callers should ensure that the target device is not RPM_SUSPENDED before 374 * using this function for requests of type DEV_PM_QOS_FLAGS. 375 */ 376 int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value) 377 { 378 int ret; 379 380 mutex_lock(&dev_pm_qos_mtx); 381 ret = __dev_pm_qos_update_request(req, new_value); 382 mutex_unlock(&dev_pm_qos_mtx); 383 return ret; 384 } 385 EXPORT_SYMBOL_GPL(dev_pm_qos_update_request); 386 387 static int __dev_pm_qos_remove_request(struct dev_pm_qos_request *req) 388 { 389 int ret; 390 391 if (!req) /*guard against callers passing in null */ 392 return -EINVAL; 393 394 if (WARN(!dev_pm_qos_request_active(req), 395 "%s() called for unknown object\n", __func__)) 396 return -EINVAL; 397 398 if (IS_ERR_OR_NULL(req->dev->power.qos)) 399 return -ENODEV; 400 401 ret = apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); 402 memset(req, 0, sizeof(*req)); 403 return ret; 404 } 405 406 /** 407 * dev_pm_qos_remove_request - modifies an existing qos request 408 * @req: handle to request list element 409 * 410 * Will remove pm qos request from the list of constraints and 411 * recompute the current target value. Call this on slow code paths. 412 * 413 * Returns 1 if the aggregated constraint value has changed, 414 * 0 if the aggregated constraint value has not changed, 415 * -EINVAL in case of wrong parameters, -ENODEV if the device has been 416 * removed from the system 417 * 418 * Callers should ensure that the target device is not RPM_SUSPENDED before 419 * using this function for requests of type DEV_PM_QOS_FLAGS. 420 */ 421 int dev_pm_qos_remove_request(struct dev_pm_qos_request *req) 422 { 423 int ret; 424 425 mutex_lock(&dev_pm_qos_mtx); 426 ret = __dev_pm_qos_remove_request(req); 427 mutex_unlock(&dev_pm_qos_mtx); 428 return ret; 429 } 430 EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request); 431 432 /** 433 * dev_pm_qos_add_notifier - sets notification entry for changes to target value 434 * of per-device PM QoS constraints 435 * 436 * @dev: target device for the constraint 437 * @notifier: notifier block managed by caller. 438 * 439 * Will register the notifier into a notification chain that gets called 440 * upon changes to the target value for the device. 441 * 442 * If the device's constraints object doesn't exist when this routine is called, 443 * it will be created (or error code will be returned if that fails). 444 */ 445 int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier) 446 { 447 int ret = 0; 448 449 mutex_lock(&dev_pm_qos_mtx); 450 451 if (IS_ERR(dev->power.qos)) 452 ret = -ENODEV; 453 else if (!dev->power.qos) 454 ret = dev_pm_qos_constraints_allocate(dev); 455 456 if (!ret) 457 ret = blocking_notifier_chain_register( 458 dev->power.qos->latency.notifiers, notifier); 459 460 mutex_unlock(&dev_pm_qos_mtx); 461 return ret; 462 } 463 EXPORT_SYMBOL_GPL(dev_pm_qos_add_notifier); 464 465 /** 466 * dev_pm_qos_remove_notifier - deletes notification for changes to target value 467 * of per-device PM QoS constraints 468 * 469 * @dev: target device for the constraint 470 * @notifier: notifier block to be removed. 471 * 472 * Will remove the notifier from the notification chain that gets called 473 * upon changes to the target value. 474 */ 475 int dev_pm_qos_remove_notifier(struct device *dev, 476 struct notifier_block *notifier) 477 { 478 int retval = 0; 479 480 mutex_lock(&dev_pm_qos_mtx); 481 482 /* Silently return if the constraints object is not present. */ 483 if (!IS_ERR_OR_NULL(dev->power.qos)) 484 retval = blocking_notifier_chain_unregister( 485 dev->power.qos->latency.notifiers, 486 notifier); 487 488 mutex_unlock(&dev_pm_qos_mtx); 489 return retval; 490 } 491 EXPORT_SYMBOL_GPL(dev_pm_qos_remove_notifier); 492 493 /** 494 * dev_pm_qos_add_global_notifier - sets notification entry for changes to 495 * target value of the PM QoS constraints for any device 496 * 497 * @notifier: notifier block managed by caller. 498 * 499 * Will register the notifier into a notification chain that gets called 500 * upon changes to the target value for any device. 501 */ 502 int dev_pm_qos_add_global_notifier(struct notifier_block *notifier) 503 { 504 return blocking_notifier_chain_register(&dev_pm_notifiers, notifier); 505 } 506 EXPORT_SYMBOL_GPL(dev_pm_qos_add_global_notifier); 507 508 /** 509 * dev_pm_qos_remove_global_notifier - deletes notification for changes to 510 * target value of PM QoS constraints for any device 511 * 512 * @notifier: notifier block to be removed. 513 * 514 * Will remove the notifier from the notification chain that gets called 515 * upon changes to the target value for any device. 516 */ 517 int dev_pm_qos_remove_global_notifier(struct notifier_block *notifier) 518 { 519 return blocking_notifier_chain_unregister(&dev_pm_notifiers, notifier); 520 } 521 EXPORT_SYMBOL_GPL(dev_pm_qos_remove_global_notifier); 522 523 /** 524 * dev_pm_qos_add_ancestor_request - Add PM QoS request for device's ancestor. 525 * @dev: Device whose ancestor to add the request for. 526 * @req: Pointer to the preallocated handle. 527 * @value: Constraint latency value. 528 */ 529 int dev_pm_qos_add_ancestor_request(struct device *dev, 530 struct dev_pm_qos_request *req, s32 value) 531 { 532 struct device *ancestor = dev->parent; 533 int ret = -ENODEV; 534 535 while (ancestor && !ancestor->power.ignore_children) 536 ancestor = ancestor->parent; 537 538 if (ancestor) 539 ret = dev_pm_qos_add_request(ancestor, req, 540 DEV_PM_QOS_LATENCY, value); 541 542 if (ret < 0) 543 req->dev = NULL; 544 545 return ret; 546 } 547 EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request); 548 549 #ifdef CONFIG_PM_RUNTIME 550 static void __dev_pm_qos_drop_user_request(struct device *dev, 551 enum dev_pm_qos_req_type type) 552 { 553 struct dev_pm_qos_request *req = NULL; 554 555 switch(type) { 556 case DEV_PM_QOS_LATENCY: 557 req = dev->power.qos->latency_req; 558 dev->power.qos->latency_req = NULL; 559 break; 560 case DEV_PM_QOS_FLAGS: 561 req = dev->power.qos->flags_req; 562 dev->power.qos->flags_req = NULL; 563 break; 564 } 565 __dev_pm_qos_remove_request(req); 566 kfree(req); 567 } 568 569 static void dev_pm_qos_drop_user_request(struct device *dev, 570 enum dev_pm_qos_req_type type) 571 { 572 mutex_lock(&dev_pm_qos_mtx); 573 __dev_pm_qos_drop_user_request(dev, type); 574 mutex_unlock(&dev_pm_qos_mtx); 575 } 576 577 /** 578 * dev_pm_qos_expose_latency_limit - Expose PM QoS latency limit to user space. 579 * @dev: Device whose PM QoS latency limit is to be exposed to user space. 580 * @value: Initial value of the latency limit. 581 */ 582 int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value) 583 { 584 struct dev_pm_qos_request *req; 585 int ret; 586 587 if (!device_is_registered(dev) || value < 0) 588 return -EINVAL; 589 590 req = kzalloc(sizeof(*req), GFP_KERNEL); 591 if (!req) 592 return -ENOMEM; 593 594 ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_LATENCY, value); 595 if (ret < 0) { 596 kfree(req); 597 return ret; 598 } 599 600 mutex_lock(&dev_pm_qos_sysfs_mtx); 601 602 mutex_lock(&dev_pm_qos_mtx); 603 604 if (IS_ERR_OR_NULL(dev->power.qos)) 605 ret = -ENODEV; 606 else if (dev->power.qos->latency_req) 607 ret = -EEXIST; 608 609 if (ret < 0) { 610 __dev_pm_qos_remove_request(req); 611 kfree(req); 612 mutex_unlock(&dev_pm_qos_mtx); 613 goto out; 614 } 615 dev->power.qos->latency_req = req; 616 617 mutex_unlock(&dev_pm_qos_mtx); 618 619 ret = pm_qos_sysfs_add_latency(dev); 620 if (ret) 621 dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY); 622 623 out: 624 mutex_unlock(&dev_pm_qos_sysfs_mtx); 625 return ret; 626 } 627 EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_limit); 628 629 static void __dev_pm_qos_hide_latency_limit(struct device *dev) 630 { 631 if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->latency_req) 632 __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY); 633 } 634 635 /** 636 * dev_pm_qos_hide_latency_limit - Hide PM QoS latency limit from user space. 637 * @dev: Device whose PM QoS latency limit is to be hidden from user space. 638 */ 639 void dev_pm_qos_hide_latency_limit(struct device *dev) 640 { 641 mutex_lock(&dev_pm_qos_sysfs_mtx); 642 643 pm_qos_sysfs_remove_latency(dev); 644 645 mutex_lock(&dev_pm_qos_mtx); 646 __dev_pm_qos_hide_latency_limit(dev); 647 mutex_unlock(&dev_pm_qos_mtx); 648 649 mutex_unlock(&dev_pm_qos_sysfs_mtx); 650 } 651 EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_limit); 652 653 /** 654 * dev_pm_qos_expose_flags - Expose PM QoS flags of a device to user space. 655 * @dev: Device whose PM QoS flags are to be exposed to user space. 656 * @val: Initial values of the flags. 657 */ 658 int dev_pm_qos_expose_flags(struct device *dev, s32 val) 659 { 660 struct dev_pm_qos_request *req; 661 int ret; 662 663 if (!device_is_registered(dev)) 664 return -EINVAL; 665 666 req = kzalloc(sizeof(*req), GFP_KERNEL); 667 if (!req) 668 return -ENOMEM; 669 670 ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_FLAGS, val); 671 if (ret < 0) { 672 kfree(req); 673 return ret; 674 } 675 676 pm_runtime_get_sync(dev); 677 mutex_lock(&dev_pm_qos_sysfs_mtx); 678 679 mutex_lock(&dev_pm_qos_mtx); 680 681 if (IS_ERR_OR_NULL(dev->power.qos)) 682 ret = -ENODEV; 683 else if (dev->power.qos->flags_req) 684 ret = -EEXIST; 685 686 if (ret < 0) { 687 __dev_pm_qos_remove_request(req); 688 kfree(req); 689 mutex_unlock(&dev_pm_qos_mtx); 690 goto out; 691 } 692 dev->power.qos->flags_req = req; 693 694 mutex_unlock(&dev_pm_qos_mtx); 695 696 ret = pm_qos_sysfs_add_flags(dev); 697 if (ret) 698 dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS); 699 700 out: 701 mutex_unlock(&dev_pm_qos_sysfs_mtx); 702 pm_runtime_put(dev); 703 return ret; 704 } 705 EXPORT_SYMBOL_GPL(dev_pm_qos_expose_flags); 706 707 static void __dev_pm_qos_hide_flags(struct device *dev) 708 { 709 if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->flags_req) 710 __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS); 711 } 712 713 /** 714 * dev_pm_qos_hide_flags - Hide PM QoS flags of a device from user space. 715 * @dev: Device whose PM QoS flags are to be hidden from user space. 716 */ 717 void dev_pm_qos_hide_flags(struct device *dev) 718 { 719 pm_runtime_get_sync(dev); 720 mutex_lock(&dev_pm_qos_sysfs_mtx); 721 722 pm_qos_sysfs_remove_flags(dev); 723 724 mutex_lock(&dev_pm_qos_mtx); 725 __dev_pm_qos_hide_flags(dev); 726 mutex_unlock(&dev_pm_qos_mtx); 727 728 mutex_unlock(&dev_pm_qos_sysfs_mtx); 729 pm_runtime_put(dev); 730 } 731 EXPORT_SYMBOL_GPL(dev_pm_qos_hide_flags); 732 733 /** 734 * dev_pm_qos_update_flags - Update PM QoS flags request owned by user space. 735 * @dev: Device to update the PM QoS flags request for. 736 * @mask: Flags to set/clear. 737 * @set: Whether to set or clear the flags (true means set). 738 */ 739 int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set) 740 { 741 s32 value; 742 int ret; 743 744 pm_runtime_get_sync(dev); 745 mutex_lock(&dev_pm_qos_mtx); 746 747 if (IS_ERR_OR_NULL(dev->power.qos) || !dev->power.qos->flags_req) { 748 ret = -EINVAL; 749 goto out; 750 } 751 752 value = dev_pm_qos_requested_flags(dev); 753 if (set) 754 value |= mask; 755 else 756 value &= ~mask; 757 758 ret = __dev_pm_qos_update_request(dev->power.qos->flags_req, value); 759 760 out: 761 mutex_unlock(&dev_pm_qos_mtx); 762 pm_runtime_put(dev); 763 return ret; 764 } 765 #else /* !CONFIG_PM_RUNTIME */ 766 static void __dev_pm_qos_hide_latency_limit(struct device *dev) {} 767 static void __dev_pm_qos_hide_flags(struct device *dev) {} 768 #endif /* CONFIG_PM_RUNTIME */ 769