2 * Devices PM QoS constraints management
4 * Copyright (C) 2011 Texas Instruments, Inc.
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.
11 * This module exposes the interface to kernel space for specifying
12 * per-device PM QoS dependencies. It provides infrastructure for registration
15 * Dependents on a QoS value : register requests
16 * Watchers of QoS value : get notified when target QoS value changes
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
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.
27 * Note about the per-device constraint data struct allocation:
28 * . The per-device constraints data struct ptr is tored into the device
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.
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 #include <trace/events/power.h>
49 static DEFINE_MUTEX(dev_pm_qos_mtx);
50 static DEFINE_MUTEX(dev_pm_qos_sysfs_mtx);
52 static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers);
55 * __dev_pm_qos_flags - Check PM QoS flags for a given device.
56 * @dev: Device to check the PM QoS flags for.
57 * @mask: Flags to check against.
59 * This routine must be called with dev->power.lock held.
61 enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask)
63 struct dev_pm_qos *qos = dev->power.qos;
64 struct pm_qos_flags *pqf;
67 if (IS_ERR_OR_NULL(qos))
68 return PM_QOS_FLAGS_UNDEFINED;
71 if (list_empty(&pqf->list))
72 return PM_QOS_FLAGS_UNDEFINED;
74 val = pqf->effective_flags & mask;
76 return (val == mask) ? PM_QOS_FLAGS_ALL : PM_QOS_FLAGS_SOME;
78 return PM_QOS_FLAGS_NONE;
82 * dev_pm_qos_flags - Check PM QoS flags for a given device (locked).
83 * @dev: Device to check the PM QoS flags for.
84 * @mask: Flags to check against.
86 enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask)
88 unsigned long irqflags;
89 enum pm_qos_flags_status ret;
91 spin_lock_irqsave(&dev->power.lock, irqflags);
92 ret = __dev_pm_qos_flags(dev, mask);
93 spin_unlock_irqrestore(&dev->power.lock, irqflags);
97 EXPORT_SYMBOL_GPL(dev_pm_qos_flags);
100 * __dev_pm_qos_read_value - Get PM QoS constraint for a given device.
101 * @dev: Device to get the PM QoS constraint value for.
103 * This routine must be called with dev->power.lock held.
105 s32 __dev_pm_qos_read_value(struct device *dev)
107 return IS_ERR_OR_NULL(dev->power.qos) ?
108 0 : pm_qos_read_value(&dev->power.qos->resume_latency);
112 * dev_pm_qos_read_value - Get PM QoS constraint for a given device (locked).
113 * @dev: Device to get the PM QoS constraint value for.
115 s32 dev_pm_qos_read_value(struct device *dev)
120 spin_lock_irqsave(&dev->power.lock, flags);
121 ret = __dev_pm_qos_read_value(dev);
122 spin_unlock_irqrestore(&dev->power.lock, flags);
128 * apply_constraint - Add/modify/remove device PM QoS request.
129 * @req: Constraint request to apply
130 * @action: Action to perform (add/update/remove).
131 * @value: Value to assign to the QoS request.
133 * Internal function to update the constraints list using the PM QoS core
134 * code and if needed call the per-device and the global notification
137 static int apply_constraint(struct dev_pm_qos_request *req,
138 enum pm_qos_req_action action, s32 value)
140 struct dev_pm_qos *qos = req->dev->power.qos;
144 case DEV_PM_QOS_RESUME_LATENCY:
145 ret = pm_qos_update_target(&qos->resume_latency,
146 &req->data.pnode, action, value);
148 value = pm_qos_read_value(&qos->resume_latency);
149 blocking_notifier_call_chain(&dev_pm_notifiers,
150 (unsigned long)value,
154 case DEV_PM_QOS_LATENCY_TOLERANCE:
155 ret = pm_qos_update_target(&qos->latency_tolerance,
156 &req->data.pnode, action, value);
158 value = pm_qos_read_value(&qos->latency_tolerance);
159 req->dev->power.set_latency_tolerance(req->dev, value);
162 case DEV_PM_QOS_FLAGS:
163 ret = pm_qos_update_flags(&qos->flags, &req->data.flr,
174 * dev_pm_qos_constraints_allocate
175 * @dev: device to allocate data for
177 * Called at the first call to add_request, for constraint data allocation
178 * Must be called with the dev_pm_qos_mtx mutex held
180 static int dev_pm_qos_constraints_allocate(struct device *dev)
182 struct dev_pm_qos *qos;
183 struct pm_qos_constraints *c;
184 struct blocking_notifier_head *n;
186 qos = kzalloc(sizeof(*qos), GFP_KERNEL);
190 n = kzalloc(sizeof(*n), GFP_KERNEL);
195 BLOCKING_INIT_NOTIFIER_HEAD(n);
197 c = &qos->resume_latency;
198 plist_head_init(&c->list);
199 c->target_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
200 c->default_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
201 c->no_constraint_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
202 c->type = PM_QOS_MIN;
205 c = &qos->latency_tolerance;
206 plist_head_init(&c->list);
207 c->target_value = PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE;
208 c->default_value = PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE;
209 c->no_constraint_value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
210 c->type = PM_QOS_MIN;
212 INIT_LIST_HEAD(&qos->flags.list);
214 spin_lock_irq(&dev->power.lock);
215 dev->power.qos = qos;
216 spin_unlock_irq(&dev->power.lock);
221 static void __dev_pm_qos_hide_latency_limit(struct device *dev);
222 static void __dev_pm_qos_hide_flags(struct device *dev);
225 * dev_pm_qos_constraints_destroy
226 * @dev: target device
228 * Called from the device PM subsystem on device removal under device_pm_lock().
230 void dev_pm_qos_constraints_destroy(struct device *dev)
232 struct dev_pm_qos *qos;
233 struct dev_pm_qos_request *req, *tmp;
234 struct pm_qos_constraints *c;
235 struct pm_qos_flags *f;
237 mutex_lock(&dev_pm_qos_sysfs_mtx);
240 * If the device's PM QoS resume latency limit or PM QoS flags have been
241 * exposed to user space, they have to be hidden at this point.
243 pm_qos_sysfs_remove_resume_latency(dev);
244 pm_qos_sysfs_remove_flags(dev);
246 mutex_lock(&dev_pm_qos_mtx);
248 __dev_pm_qos_hide_latency_limit(dev);
249 __dev_pm_qos_hide_flags(dev);
251 qos = dev->power.qos;
255 /* Flush the constraints lists for the device. */
256 c = &qos->resume_latency;
257 plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) {
259 * Update constraints list and call the notification
260 * callbacks if needed
262 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
263 memset(req, 0, sizeof(*req));
265 c = &qos->latency_tolerance;
266 plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) {
267 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
268 memset(req, 0, sizeof(*req));
271 list_for_each_entry_safe(req, tmp, &f->list, data.flr.node) {
272 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
273 memset(req, 0, sizeof(*req));
276 spin_lock_irq(&dev->power.lock);
277 dev->power.qos = ERR_PTR(-ENODEV);
278 spin_unlock_irq(&dev->power.lock);
284 mutex_unlock(&dev_pm_qos_mtx);
286 mutex_unlock(&dev_pm_qos_sysfs_mtx);
289 static bool dev_pm_qos_invalid_request(struct device *dev,
290 struct dev_pm_qos_request *req)
292 return !req || (req->type == DEV_PM_QOS_LATENCY_TOLERANCE
293 && !dev->power.set_latency_tolerance);
296 static int __dev_pm_qos_add_request(struct device *dev,
297 struct dev_pm_qos_request *req,
298 enum dev_pm_qos_req_type type, s32 value)
302 if (!dev || dev_pm_qos_invalid_request(dev, req))
305 if (WARN(dev_pm_qos_request_active(req),
306 "%s() called for already added request\n", __func__))
309 if (IS_ERR(dev->power.qos))
311 else if (!dev->power.qos)
312 ret = dev_pm_qos_constraints_allocate(dev);
314 trace_dev_pm_qos_add_request(dev_name(dev), type, value);
318 ret = apply_constraint(req, PM_QOS_ADD_REQ, value);
324 * dev_pm_qos_add_request - inserts new qos request into the list
325 * @dev: target device for the constraint
326 * @req: pointer to a preallocated handle
327 * @type: type of the request
328 * @value: defines the qos request
330 * This function inserts a new entry in the device constraints list of
331 * requested qos performance characteristics. It recomputes the aggregate
332 * QoS expectations of parameters and initializes the dev_pm_qos_request
333 * handle. Caller needs to save this handle for later use in updates and
336 * Returns 1 if the aggregated constraint value has changed,
337 * 0 if the aggregated constraint value has not changed,
338 * -EINVAL in case of wrong parameters, -ENOMEM if there's not enough memory
339 * to allocate for data structures, -ENODEV if the device has just been removed
342 * Callers should ensure that the target device is not RPM_SUSPENDED before
343 * using this function for requests of type DEV_PM_QOS_FLAGS.
345 int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
346 enum dev_pm_qos_req_type type, s32 value)
350 mutex_lock(&dev_pm_qos_mtx);
351 ret = __dev_pm_qos_add_request(dev, req, type, value);
352 mutex_unlock(&dev_pm_qos_mtx);
355 EXPORT_SYMBOL_GPL(dev_pm_qos_add_request);
358 * __dev_pm_qos_update_request - Modify an existing device PM QoS request.
359 * @req : PM QoS request to modify.
360 * @new_value: New value to request.
362 static int __dev_pm_qos_update_request(struct dev_pm_qos_request *req,
368 if (!req) /*guard against callers passing in null */
371 if (WARN(!dev_pm_qos_request_active(req),
372 "%s() called for unknown object\n", __func__))
375 if (IS_ERR_OR_NULL(req->dev->power.qos))
379 case DEV_PM_QOS_RESUME_LATENCY:
380 case DEV_PM_QOS_LATENCY_TOLERANCE:
381 curr_value = req->data.pnode.prio;
383 case DEV_PM_QOS_FLAGS:
384 curr_value = req->data.flr.flags;
390 trace_dev_pm_qos_update_request(dev_name(req->dev), req->type,
392 if (curr_value != new_value)
393 ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
399 * dev_pm_qos_update_request - modifies an existing qos request
400 * @req : handle to list element holding a dev_pm_qos request to use
401 * @new_value: defines the qos request
403 * Updates an existing dev PM qos request along with updating the
406 * Attempts are made to make this code callable on hot code paths.
408 * Returns 1 if the aggregated constraint value has changed,
409 * 0 if the aggregated constraint value has not changed,
410 * -EINVAL in case of wrong parameters, -ENODEV if the device has been
411 * removed from the system
413 * Callers should ensure that the target device is not RPM_SUSPENDED before
414 * using this function for requests of type DEV_PM_QOS_FLAGS.
416 int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
420 mutex_lock(&dev_pm_qos_mtx);
421 ret = __dev_pm_qos_update_request(req, new_value);
422 mutex_unlock(&dev_pm_qos_mtx);
425 EXPORT_SYMBOL_GPL(dev_pm_qos_update_request);
427 static int __dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
431 if (!req) /*guard against callers passing in null */
434 if (WARN(!dev_pm_qos_request_active(req),
435 "%s() called for unknown object\n", __func__))
438 if (IS_ERR_OR_NULL(req->dev->power.qos))
441 trace_dev_pm_qos_remove_request(dev_name(req->dev), req->type,
442 PM_QOS_DEFAULT_VALUE);
443 ret = apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
444 memset(req, 0, sizeof(*req));
449 * dev_pm_qos_remove_request - modifies an existing qos request
450 * @req: handle to request list element
452 * Will remove pm qos request from the list of constraints and
453 * recompute the current target value. Call this on slow code paths.
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
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.
463 int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
467 mutex_lock(&dev_pm_qos_mtx);
468 ret = __dev_pm_qos_remove_request(req);
469 mutex_unlock(&dev_pm_qos_mtx);
472 EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request);
475 * dev_pm_qos_add_notifier - sets notification entry for changes to target value
476 * of per-device PM QoS constraints
478 * @dev: target device for the constraint
479 * @notifier: notifier block managed by caller.
481 * Will register the notifier into a notification chain that gets called
482 * upon changes to the target value for the device.
484 * If the device's constraints object doesn't exist when this routine is called,
485 * it will be created (or error code will be returned if that fails).
487 int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier)
491 mutex_lock(&dev_pm_qos_mtx);
493 if (IS_ERR(dev->power.qos))
495 else if (!dev->power.qos)
496 ret = dev_pm_qos_constraints_allocate(dev);
499 ret = blocking_notifier_chain_register(dev->power.qos->resume_latency.notifiers,
502 mutex_unlock(&dev_pm_qos_mtx);
505 EXPORT_SYMBOL_GPL(dev_pm_qos_add_notifier);
508 * dev_pm_qos_remove_notifier - deletes notification for changes to target value
509 * of per-device PM QoS constraints
511 * @dev: target device for the constraint
512 * @notifier: notifier block to be removed.
514 * Will remove the notifier from the notification chain that gets called
515 * upon changes to the target value.
517 int dev_pm_qos_remove_notifier(struct device *dev,
518 struct notifier_block *notifier)
522 mutex_lock(&dev_pm_qos_mtx);
524 /* Silently return if the constraints object is not present. */
525 if (!IS_ERR_OR_NULL(dev->power.qos))
526 retval = blocking_notifier_chain_unregister(dev->power.qos->resume_latency.notifiers,
529 mutex_unlock(&dev_pm_qos_mtx);
532 EXPORT_SYMBOL_GPL(dev_pm_qos_remove_notifier);
535 * dev_pm_qos_add_global_notifier - sets notification entry for changes to
536 * target value of the PM QoS constraints for any device
538 * @notifier: notifier block managed by caller.
540 * Will register the notifier into a notification chain that gets called
541 * upon changes to the target value for any device.
543 int dev_pm_qos_add_global_notifier(struct notifier_block *notifier)
545 return blocking_notifier_chain_register(&dev_pm_notifiers, notifier);
547 EXPORT_SYMBOL_GPL(dev_pm_qos_add_global_notifier);
550 * dev_pm_qos_remove_global_notifier - deletes notification for changes to
551 * target value of PM QoS constraints for any device
553 * @notifier: notifier block to be removed.
555 * Will remove the notifier from the notification chain that gets called
556 * upon changes to the target value for any device.
558 int dev_pm_qos_remove_global_notifier(struct notifier_block *notifier)
560 return blocking_notifier_chain_unregister(&dev_pm_notifiers, notifier);
562 EXPORT_SYMBOL_GPL(dev_pm_qos_remove_global_notifier);
565 * dev_pm_qos_add_ancestor_request - Add PM QoS request for device's ancestor.
566 * @dev: Device whose ancestor to add the request for.
567 * @req: Pointer to the preallocated handle.
568 * @type: Type of the request.
569 * @value: Constraint latency value.
571 int dev_pm_qos_add_ancestor_request(struct device *dev,
572 struct dev_pm_qos_request *req,
573 enum dev_pm_qos_req_type type, s32 value)
575 struct device *ancestor = dev->parent;
579 case DEV_PM_QOS_RESUME_LATENCY:
580 while (ancestor && !ancestor->power.ignore_children)
581 ancestor = ancestor->parent;
584 case DEV_PM_QOS_LATENCY_TOLERANCE:
585 while (ancestor && !ancestor->power.set_latency_tolerance)
586 ancestor = ancestor->parent;
593 ret = dev_pm_qos_add_request(ancestor, req, type, value);
600 EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request);
602 static void __dev_pm_qos_drop_user_request(struct device *dev,
603 enum dev_pm_qos_req_type type)
605 struct dev_pm_qos_request *req = NULL;
608 case DEV_PM_QOS_RESUME_LATENCY:
609 req = dev->power.qos->resume_latency_req;
610 dev->power.qos->resume_latency_req = NULL;
612 case DEV_PM_QOS_LATENCY_TOLERANCE:
613 req = dev->power.qos->latency_tolerance_req;
614 dev->power.qos->latency_tolerance_req = NULL;
616 case DEV_PM_QOS_FLAGS:
617 req = dev->power.qos->flags_req;
618 dev->power.qos->flags_req = NULL;
621 __dev_pm_qos_remove_request(req);
625 static void dev_pm_qos_drop_user_request(struct device *dev,
626 enum dev_pm_qos_req_type type)
628 mutex_lock(&dev_pm_qos_mtx);
629 __dev_pm_qos_drop_user_request(dev, type);
630 mutex_unlock(&dev_pm_qos_mtx);
634 * dev_pm_qos_expose_latency_limit - Expose PM QoS latency limit to user space.
635 * @dev: Device whose PM QoS latency limit is to be exposed to user space.
636 * @value: Initial value of the latency limit.
638 int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
640 struct dev_pm_qos_request *req;
643 if (!device_is_registered(dev) || value < 0)
646 req = kzalloc(sizeof(*req), GFP_KERNEL);
650 ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_RESUME_LATENCY, value);
656 mutex_lock(&dev_pm_qos_sysfs_mtx);
658 mutex_lock(&dev_pm_qos_mtx);
660 if (IS_ERR_OR_NULL(dev->power.qos))
662 else if (dev->power.qos->resume_latency_req)
666 __dev_pm_qos_remove_request(req);
668 mutex_unlock(&dev_pm_qos_mtx);
671 dev->power.qos->resume_latency_req = req;
673 mutex_unlock(&dev_pm_qos_mtx);
675 ret = pm_qos_sysfs_add_resume_latency(dev);
677 dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_RESUME_LATENCY);
680 mutex_unlock(&dev_pm_qos_sysfs_mtx);
683 EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_limit);
685 static void __dev_pm_qos_hide_latency_limit(struct device *dev)
687 if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->resume_latency_req)
688 __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_RESUME_LATENCY);
692 * dev_pm_qos_hide_latency_limit - Hide PM QoS latency limit from user space.
693 * @dev: Device whose PM QoS latency limit is to be hidden from user space.
695 void dev_pm_qos_hide_latency_limit(struct device *dev)
697 mutex_lock(&dev_pm_qos_sysfs_mtx);
699 pm_qos_sysfs_remove_resume_latency(dev);
701 mutex_lock(&dev_pm_qos_mtx);
702 __dev_pm_qos_hide_latency_limit(dev);
703 mutex_unlock(&dev_pm_qos_mtx);
705 mutex_unlock(&dev_pm_qos_sysfs_mtx);
707 EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_limit);
710 * dev_pm_qos_expose_flags - Expose PM QoS flags of a device to user space.
711 * @dev: Device whose PM QoS flags are to be exposed to user space.
712 * @val: Initial values of the flags.
714 int dev_pm_qos_expose_flags(struct device *dev, s32 val)
716 struct dev_pm_qos_request *req;
719 if (!device_is_registered(dev))
722 req = kzalloc(sizeof(*req), GFP_KERNEL);
726 ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_FLAGS, val);
732 pm_runtime_get_sync(dev);
733 mutex_lock(&dev_pm_qos_sysfs_mtx);
735 mutex_lock(&dev_pm_qos_mtx);
737 if (IS_ERR_OR_NULL(dev->power.qos))
739 else if (dev->power.qos->flags_req)
743 __dev_pm_qos_remove_request(req);
745 mutex_unlock(&dev_pm_qos_mtx);
748 dev->power.qos->flags_req = req;
750 mutex_unlock(&dev_pm_qos_mtx);
752 ret = pm_qos_sysfs_add_flags(dev);
754 dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
757 mutex_unlock(&dev_pm_qos_sysfs_mtx);
761 EXPORT_SYMBOL_GPL(dev_pm_qos_expose_flags);
763 static void __dev_pm_qos_hide_flags(struct device *dev)
765 if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->flags_req)
766 __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
770 * dev_pm_qos_hide_flags - Hide PM QoS flags of a device from user space.
771 * @dev: Device whose PM QoS flags are to be hidden from user space.
773 void dev_pm_qos_hide_flags(struct device *dev)
775 pm_runtime_get_sync(dev);
776 mutex_lock(&dev_pm_qos_sysfs_mtx);
778 pm_qos_sysfs_remove_flags(dev);
780 mutex_lock(&dev_pm_qos_mtx);
781 __dev_pm_qos_hide_flags(dev);
782 mutex_unlock(&dev_pm_qos_mtx);
784 mutex_unlock(&dev_pm_qos_sysfs_mtx);
787 EXPORT_SYMBOL_GPL(dev_pm_qos_hide_flags);
790 * dev_pm_qos_update_flags - Update PM QoS flags request owned by user space.
791 * @dev: Device to update the PM QoS flags request for.
792 * @mask: Flags to set/clear.
793 * @set: Whether to set or clear the flags (true means set).
795 int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set)
800 pm_runtime_get_sync(dev);
801 mutex_lock(&dev_pm_qos_mtx);
803 if (IS_ERR_OR_NULL(dev->power.qos) || !dev->power.qos->flags_req) {
808 value = dev_pm_qos_requested_flags(dev);
814 ret = __dev_pm_qos_update_request(dev->power.qos->flags_req, value);
817 mutex_unlock(&dev_pm_qos_mtx);
823 * dev_pm_qos_get_user_latency_tolerance - Get user space latency tolerance.
824 * @dev: Device to obtain the user space latency tolerance for.
826 s32 dev_pm_qos_get_user_latency_tolerance(struct device *dev)
830 mutex_lock(&dev_pm_qos_mtx);
831 ret = IS_ERR_OR_NULL(dev->power.qos)
832 || !dev->power.qos->latency_tolerance_req ?
833 PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT :
834 dev->power.qos->latency_tolerance_req->data.pnode.prio;
835 mutex_unlock(&dev_pm_qos_mtx);
840 * dev_pm_qos_update_user_latency_tolerance - Update user space latency tolerance.
841 * @dev: Device to update the user space latency tolerance for.
842 * @val: New user space latency tolerance for @dev (negative values disable).
844 int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val)
848 mutex_lock(&dev_pm_qos_mtx);
850 if (IS_ERR_OR_NULL(dev->power.qos)
851 || !dev->power.qos->latency_tolerance_req) {
852 struct dev_pm_qos_request *req;
858 req = kzalloc(sizeof(*req), GFP_KERNEL);
863 ret = __dev_pm_qos_add_request(dev, req, DEV_PM_QOS_LATENCY_TOLERANCE, val);
868 dev->power.qos->latency_tolerance_req = req;
871 __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY_TOLERANCE);
874 ret = __dev_pm_qos_update_request(dev->power.qos->latency_tolerance_req, val);
879 mutex_unlock(&dev_pm_qos_mtx);