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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 if (type == DEV_PM_QOS_RESUME_LATENCY) {
119 ret = IS_ERR_OR_NULL(qos) ? PM_QOS_RESUME_LATENCY_NO_CONSTRAINT
120 : pm_qos_read_value(&qos->resume_latency);
121 } else {
122 WARN_ON(1);
123 ret = 0;
124 }
125
126 spin_unlock_irqrestore(&dev->power.lock, flags);
127
128 return ret;
129}
130
131/**
132 * apply_constraint - Add/modify/remove device PM QoS request.
133 * @req: Constraint request to apply
134 * @action: Action to perform (add/update/remove).
135 * @value: Value to assign to the QoS request.
136 *
137 * Internal function to update the constraints list using the PM QoS core
138 * code and if needed call the per-device callbacks.
139 */
140static int apply_constraint(struct dev_pm_qos_request *req,
141 enum pm_qos_req_action action, s32 value)
142{
143 struct dev_pm_qos *qos = req->dev->power.qos;
144 int ret;
145
146 switch(req->type) {
147 case DEV_PM_QOS_RESUME_LATENCY:
148 if (WARN_ON(action != PM_QOS_REMOVE_REQ && value < 0))
149 value = 0;
150
151 ret = pm_qos_update_target(&qos->resume_latency,
152 &req->data.pnode, action, value);
153 break;
154 case DEV_PM_QOS_LATENCY_TOLERANCE:
155 ret = pm_qos_update_target(&qos->latency_tolerance,
156 &req->data.pnode, action, value);
157 if (ret) {
158 value = pm_qos_read_value(&qos->latency_tolerance);
159 req->dev->power.set_latency_tolerance(req->dev, value);
160 }
161 break;
162 case DEV_PM_QOS_FLAGS:
163 ret = pm_qos_update_flags(&qos->flags, &req->data.flr,
164 action, value);
165 break;
166 default:
167 ret = -EINVAL;
168 }
169
170 return ret;
171}
172
173/*
174 * dev_pm_qos_constraints_allocate
175 * @dev: device to allocate data for
176 *
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
179 */
180static int dev_pm_qos_constraints_allocate(struct device *dev)
181{
182 struct dev_pm_qos *qos;
183 struct pm_qos_constraints *c;
184 struct blocking_notifier_head *n;
185
186 qos = kzalloc(sizeof(*qos), GFP_KERNEL);
187 if (!qos)
188 return -ENOMEM;
189
190 n = kzalloc(3 * sizeof(*n), GFP_KERNEL);
191 if (!n) {
192 kfree(qos);
193 return -ENOMEM;
194 }
195
196 c = &qos->resume_latency;
197 plist_head_init(&c->list);
198 c->target_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
199 c->default_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
200 c->no_constraint_value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
201 c->type = PM_QOS_MIN;
202 c->notifiers = n;
203 BLOCKING_INIT_NOTIFIER_HEAD(n);
204
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;
211
212 INIT_LIST_HEAD(&qos->flags.list);
213
214 spin_lock_irq(&dev->power.lock);
215 dev->power.qos = qos;
216 spin_unlock_irq(&dev->power.lock);
217
218 return 0;
219}
220
221static void __dev_pm_qos_hide_latency_limit(struct device *dev);
222static void __dev_pm_qos_hide_flags(struct device *dev);
223
224/**
225 * dev_pm_qos_constraints_destroy
226 * @dev: target device
227 *
228 * Called from the device PM subsystem on device removal under device_pm_lock().
229 */
230void dev_pm_qos_constraints_destroy(struct device *dev)
231{
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;
236
237 mutex_lock(&dev_pm_qos_sysfs_mtx);
238
239 /*
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.
242 */
243 pm_qos_sysfs_remove_resume_latency(dev);
244 pm_qos_sysfs_remove_flags(dev);
245
246 mutex_lock(&dev_pm_qos_mtx);
247
248 __dev_pm_qos_hide_latency_limit(dev);
249 __dev_pm_qos_hide_flags(dev);
250
251 qos = dev->power.qos;
252 if (!qos)
253 goto out;
254
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) {
258 /*
259 * Update constraints list and call the notification
260 * callbacks if needed
261 */
262 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
263 memset(req, 0, sizeof(*req));
264 }
265
266 c = &qos->latency_tolerance;
267 plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) {
268 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
269 memset(req, 0, sizeof(*req));
270 }
271
272 f = &qos->flags;
273 list_for_each_entry_safe(req, tmp, &f->list, data.flr.node) {
274 apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
275 memset(req, 0, sizeof(*req));
276 }
277
278 spin_lock_irq(&dev->power.lock);
279 dev->power.qos = ERR_PTR(-ENODEV);
280 spin_unlock_irq(&dev->power.lock);
281
282 kfree(qos->resume_latency.notifiers);
283 kfree(qos);
284
285 out:
286 mutex_unlock(&dev_pm_qos_mtx);
287
288 mutex_unlock(&dev_pm_qos_sysfs_mtx);
289}
290
291static bool dev_pm_qos_invalid_req_type(struct device *dev,
292 enum dev_pm_qos_req_type type)
293{
294 return type == DEV_PM_QOS_LATENCY_TOLERANCE &&
295 !dev->power.set_latency_tolerance;
296}
297
298static int __dev_pm_qos_add_request(struct device *dev,
299 struct dev_pm_qos_request *req,
300 enum dev_pm_qos_req_type type, s32 value)
301{
302 int ret = 0;
303
304 if (!dev || !req || dev_pm_qos_invalid_req_type(dev, type))
305 return -EINVAL;
306
307 if (WARN(dev_pm_qos_request_active(req),
308 "%s() called for already added request\n", __func__))
309 return -EINVAL;
310
311 if (IS_ERR(dev->power.qos))
312 ret = -ENODEV;
313 else if (!dev->power.qos)
314 ret = dev_pm_qos_constraints_allocate(dev);
315
316 trace_dev_pm_qos_add_request(dev_name(dev), type, value);
317 if (!ret) {
318 req->dev = dev;
319 req->type = type;
320 ret = apply_constraint(req, PM_QOS_ADD_REQ, value);
321 }
322 return ret;
323}
324
325/**
326 * dev_pm_qos_add_request - inserts new qos request into the list
327 * @dev: target device for the constraint
328 * @req: pointer to a preallocated handle
329 * @type: type of the request
330 * @value: defines the qos request
331 *
332 * This function inserts a new entry in the device constraints list of
333 * requested qos performance characteristics. It recomputes the aggregate
334 * QoS expectations of parameters and initializes the dev_pm_qos_request
335 * handle. Caller needs to save this handle for later use in updates and
336 * removal.
337 *
338 * Returns 1 if the aggregated constraint value has changed,
339 * 0 if the aggregated constraint value has not changed,
340 * -EINVAL in case of wrong parameters, -ENOMEM if there's not enough memory
341 * to allocate for data structures, -ENODEV if the device has just been removed
342 * from the system.
343 *
344 * Callers should ensure that the target device is not RPM_SUSPENDED before
345 * using this function for requests of type DEV_PM_QOS_FLAGS.
346 */
347int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
348 enum dev_pm_qos_req_type type, s32 value)
349{
350 int ret;
351
352 mutex_lock(&dev_pm_qos_mtx);
353 ret = __dev_pm_qos_add_request(dev, req, type, value);
354 mutex_unlock(&dev_pm_qos_mtx);
355 return ret;
356}
357EXPORT_SYMBOL_GPL(dev_pm_qos_add_request);
358
359/**
360 * __dev_pm_qos_update_request - Modify an existing device PM QoS request.
361 * @req : PM QoS request to modify.
362 * @new_value: New value to request.
363 */
364static int __dev_pm_qos_update_request(struct dev_pm_qos_request *req,
365 s32 new_value)
366{
367 s32 curr_value;
368 int ret = 0;
369
370 if (!req) /*guard against callers passing in null */
371 return -EINVAL;
372
373 if (WARN(!dev_pm_qos_request_active(req),
374 "%s() called for unknown object\n", __func__))
375 return -EINVAL;
376
377 if (IS_ERR_OR_NULL(req->dev->power.qos))
378 return -ENODEV;
379
380 switch(req->type) {
381 case DEV_PM_QOS_RESUME_LATENCY:
382 case DEV_PM_QOS_LATENCY_TOLERANCE:
383 curr_value = req->data.pnode.prio;
384 break;
385 case DEV_PM_QOS_FLAGS:
386 curr_value = req->data.flr.flags;
387 break;
388 default:
389 return -EINVAL;
390 }
391
392 trace_dev_pm_qos_update_request(dev_name(req->dev), req->type,
393 new_value);
394 if (curr_value != new_value)
395 ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
396
397 return ret;
398}
399
400/**
401 * dev_pm_qos_update_request - modifies an existing qos request
402 * @req : handle to list element holding a dev_pm_qos request to use
403 * @new_value: defines the qos request
404 *
405 * Updates an existing dev PM qos request along with updating the
406 * target value.
407 *
408 * Attempts are made to make this code callable on hot code paths.
409 *
410 * Returns 1 if the aggregated constraint value has changed,
411 * 0 if the aggregated constraint value has not changed,
412 * -EINVAL in case of wrong parameters, -ENODEV if the device has been
413 * removed from the system
414 *
415 * Callers should ensure that the target device is not RPM_SUSPENDED before
416 * using this function for requests of type DEV_PM_QOS_FLAGS.
417 */
418int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
419{
420 int ret;
421
422 mutex_lock(&dev_pm_qos_mtx);
423 ret = __dev_pm_qos_update_request(req, new_value);
424 mutex_unlock(&dev_pm_qos_mtx);
425 return ret;
426}
427EXPORT_SYMBOL_GPL(dev_pm_qos_update_request);
428
429static int __dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
430{
431 int ret;
432
433 if (!req) /*guard against callers passing in null */
434 return -EINVAL;
435
436 if (WARN(!dev_pm_qos_request_active(req),
437 "%s() called for unknown object\n", __func__))
438 return -EINVAL;
439
440 if (IS_ERR_OR_NULL(req->dev->power.qos))
441 return -ENODEV;
442
443 trace_dev_pm_qos_remove_request(dev_name(req->dev), req->type,
444 PM_QOS_DEFAULT_VALUE);
445 ret = apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
446 memset(req, 0, sizeof(*req));
447 return ret;
448}
449
450/**
451 * dev_pm_qos_remove_request - modifies an existing qos request
452 * @req: handle to request list element
453 *
454 * Will remove pm qos request from the list of constraints and
455 * recompute the current target value. Call this on slow code paths.
456 *
457 * Returns 1 if the aggregated constraint value has changed,
458 * 0 if the aggregated constraint value has not changed,
459 * -EINVAL in case of wrong parameters, -ENODEV if the device has been
460 * removed from the system
461 *
462 * Callers should ensure that the target device is not RPM_SUSPENDED before
463 * using this function for requests of type DEV_PM_QOS_FLAGS.
464 */
465int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
466{
467 int ret;
468
469 mutex_lock(&dev_pm_qos_mtx);
470 ret = __dev_pm_qos_remove_request(req);
471 mutex_unlock(&dev_pm_qos_mtx);
472 return ret;
473}
474EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request);
475
476/**
477 * dev_pm_qos_add_notifier - sets notification entry for changes to target value
478 * of per-device PM QoS constraints
479 *
480 * @dev: target device for the constraint
481 * @notifier: notifier block managed by caller.
482 * @type: request type.
483 *
484 * Will register the notifier into a notification chain that gets called
485 * upon changes to the target value for the device.
486 *
487 * If the device's constraints object doesn't exist when this routine is called,
488 * it will be created (or error code will be returned if that fails).
489 */
490int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier,
491 enum dev_pm_qos_req_type type)
492{
493 int ret = 0;
494
495 mutex_lock(&dev_pm_qos_mtx);
496
497 if (IS_ERR(dev->power.qos))
498 ret = -ENODEV;
499 else if (!dev->power.qos)
500 ret = dev_pm_qos_constraints_allocate(dev);
501
502 if (ret)
503 goto unlock;
504
505 switch (type) {
506 case DEV_PM_QOS_RESUME_LATENCY:
507 ret = blocking_notifier_chain_register(dev->power.qos->resume_latency.notifiers,
508 notifier);
509 break;
510 default:
511 WARN_ON(1);
512 ret = -EINVAL;
513 }
514
515unlock:
516 mutex_unlock(&dev_pm_qos_mtx);
517 return ret;
518}
519EXPORT_SYMBOL_GPL(dev_pm_qos_add_notifier);
520
521/**
522 * dev_pm_qos_remove_notifier - deletes notification for changes to target value
523 * of per-device PM QoS constraints
524 *
525 * @dev: target device for the constraint
526 * @notifier: notifier block to be removed.
527 * @type: request type.
528 *
529 * Will remove the notifier from the notification chain that gets called
530 * upon changes to the target value.
531 */
532int dev_pm_qos_remove_notifier(struct device *dev,
533 struct notifier_block *notifier,
534 enum dev_pm_qos_req_type type)
535{
536 int ret = 0;
537
538 mutex_lock(&dev_pm_qos_mtx);
539
540 /* Silently return if the constraints object is not present. */
541 if (IS_ERR_OR_NULL(dev->power.qos))
542 goto unlock;
543
544 switch (type) {
545 case DEV_PM_QOS_RESUME_LATENCY:
546 ret = blocking_notifier_chain_unregister(dev->power.qos->resume_latency.notifiers,
547 notifier);
548 break;
549 default:
550 WARN_ON(1);
551 ret = -EINVAL;
552 }
553
554unlock:
555 mutex_unlock(&dev_pm_qos_mtx);
556 return ret;
557}
558EXPORT_SYMBOL_GPL(dev_pm_qos_remove_notifier);
559
560/**
561 * dev_pm_qos_add_ancestor_request - Add PM QoS request for device's ancestor.
562 * @dev: Device whose ancestor to add the request for.
563 * @req: Pointer to the preallocated handle.
564 * @type: Type of the request.
565 * @value: Constraint latency value.
566 */
567int dev_pm_qos_add_ancestor_request(struct device *dev,
568 struct dev_pm_qos_request *req,
569 enum dev_pm_qos_req_type type, s32 value)
570{
571 struct device *ancestor = dev->parent;
572 int ret = -ENODEV;
573
574 switch (type) {
575 case DEV_PM_QOS_RESUME_LATENCY:
576 while (ancestor && !ancestor->power.ignore_children)
577 ancestor = ancestor->parent;
578
579 break;
580 case DEV_PM_QOS_LATENCY_TOLERANCE:
581 while (ancestor && !ancestor->power.set_latency_tolerance)
582 ancestor = ancestor->parent;
583
584 break;
585 default:
586 ancestor = NULL;
587 }
588 if (ancestor)
589 ret = dev_pm_qos_add_request(ancestor, req, type, value);
590
591 if (ret < 0)
592 req->dev = NULL;
593
594 return ret;
595}
596EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request);
597
598static void __dev_pm_qos_drop_user_request(struct device *dev,
599 enum dev_pm_qos_req_type type)
600{
601 struct dev_pm_qos_request *req = NULL;
602
603 switch(type) {
604 case DEV_PM_QOS_RESUME_LATENCY:
605 req = dev->power.qos->resume_latency_req;
606 dev->power.qos->resume_latency_req = NULL;
607 break;
608 case DEV_PM_QOS_LATENCY_TOLERANCE:
609 req = dev->power.qos->latency_tolerance_req;
610 dev->power.qos->latency_tolerance_req = NULL;
611 break;
612 case DEV_PM_QOS_FLAGS:
613 req = dev->power.qos->flags_req;
614 dev->power.qos->flags_req = NULL;
615 break;
616 default:
617 WARN_ON(1);
618 return;
619 }
620 __dev_pm_qos_remove_request(req);
621 kfree(req);
622}
623
624static void dev_pm_qos_drop_user_request(struct device *dev,
625 enum dev_pm_qos_req_type type)
626{
627 mutex_lock(&dev_pm_qos_mtx);
628 __dev_pm_qos_drop_user_request(dev, type);
629 mutex_unlock(&dev_pm_qos_mtx);
630}
631
632/**
633 * dev_pm_qos_expose_latency_limit - Expose PM QoS latency limit to user space.
634 * @dev: Device whose PM QoS latency limit is to be exposed to user space.
635 * @value: Initial value of the latency limit.
636 */
637int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
638{
639 struct dev_pm_qos_request *req;
640 int ret;
641
642 if (!device_is_registered(dev) || value < 0)
643 return -EINVAL;
644
645 req = kzalloc(sizeof(*req), GFP_KERNEL);
646 if (!req)
647 return -ENOMEM;
648
649 ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_RESUME_LATENCY, value);
650 if (ret < 0) {
651 kfree(req);
652 return ret;
653 }
654
655 mutex_lock(&dev_pm_qos_sysfs_mtx);
656
657 mutex_lock(&dev_pm_qos_mtx);
658
659 if (IS_ERR_OR_NULL(dev->power.qos))
660 ret = -ENODEV;
661 else if (dev->power.qos->resume_latency_req)
662 ret = -EEXIST;
663
664 if (ret < 0) {
665 __dev_pm_qos_remove_request(req);
666 kfree(req);
667 mutex_unlock(&dev_pm_qos_mtx);
668 goto out;
669 }
670 dev->power.qos->resume_latency_req = req;
671
672 mutex_unlock(&dev_pm_qos_mtx);
673
674 ret = pm_qos_sysfs_add_resume_latency(dev);
675 if (ret)
676 dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_RESUME_LATENCY);
677
678 out:
679 mutex_unlock(&dev_pm_qos_sysfs_mtx);
680 return ret;
681}
682EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_limit);
683
684static void __dev_pm_qos_hide_latency_limit(struct device *dev)
685{
686 if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->resume_latency_req)
687 __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_RESUME_LATENCY);
688}
689
690/**
691 * dev_pm_qos_hide_latency_limit - Hide PM QoS latency limit from user space.
692 * @dev: Device whose PM QoS latency limit is to be hidden from user space.
693 */
694void dev_pm_qos_hide_latency_limit(struct device *dev)
695{
696 mutex_lock(&dev_pm_qos_sysfs_mtx);
697
698 pm_qos_sysfs_remove_resume_latency(dev);
699
700 mutex_lock(&dev_pm_qos_mtx);
701 __dev_pm_qos_hide_latency_limit(dev);
702 mutex_unlock(&dev_pm_qos_mtx);
703
704 mutex_unlock(&dev_pm_qos_sysfs_mtx);
705}
706EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_limit);
707
708/**
709 * dev_pm_qos_expose_flags - Expose PM QoS flags of a device to user space.
710 * @dev: Device whose PM QoS flags are to be exposed to user space.
711 * @val: Initial values of the flags.
712 */
713int dev_pm_qos_expose_flags(struct device *dev, s32 val)
714{
715 struct dev_pm_qos_request *req;
716 int ret;
717
718 if (!device_is_registered(dev))
719 return -EINVAL;
720
721 req = kzalloc(sizeof(*req), GFP_KERNEL);
722 if (!req)
723 return -ENOMEM;
724
725 ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_FLAGS, val);
726 if (ret < 0) {
727 kfree(req);
728 return ret;
729 }
730
731 pm_runtime_get_sync(dev);
732 mutex_lock(&dev_pm_qos_sysfs_mtx);
733
734 mutex_lock(&dev_pm_qos_mtx);
735
736 if (IS_ERR_OR_NULL(dev->power.qos))
737 ret = -ENODEV;
738 else if (dev->power.qos->flags_req)
739 ret = -EEXIST;
740
741 if (ret < 0) {
742 __dev_pm_qos_remove_request(req);
743 kfree(req);
744 mutex_unlock(&dev_pm_qos_mtx);
745 goto out;
746 }
747 dev->power.qos->flags_req = req;
748
749 mutex_unlock(&dev_pm_qos_mtx);
750
751 ret = pm_qos_sysfs_add_flags(dev);
752 if (ret)
753 dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
754
755 out:
756 mutex_unlock(&dev_pm_qos_sysfs_mtx);
757 pm_runtime_put(dev);
758 return ret;
759}
760EXPORT_SYMBOL_GPL(dev_pm_qos_expose_flags);
761
762static void __dev_pm_qos_hide_flags(struct device *dev)
763{
764 if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->flags_req)
765 __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
766}
767
768/**
769 * dev_pm_qos_hide_flags - Hide PM QoS flags of a device from user space.
770 * @dev: Device whose PM QoS flags are to be hidden from user space.
771 */
772void dev_pm_qos_hide_flags(struct device *dev)
773{
774 pm_runtime_get_sync(dev);
775 mutex_lock(&dev_pm_qos_sysfs_mtx);
776
777 pm_qos_sysfs_remove_flags(dev);
778
779 mutex_lock(&dev_pm_qos_mtx);
780 __dev_pm_qos_hide_flags(dev);
781 mutex_unlock(&dev_pm_qos_mtx);
782
783 mutex_unlock(&dev_pm_qos_sysfs_mtx);
784 pm_runtime_put(dev);
785}
786EXPORT_SYMBOL_GPL(dev_pm_qos_hide_flags);
787
788/**
789 * dev_pm_qos_update_flags - Update PM QoS flags request owned by user space.
790 * @dev: Device to update the PM QoS flags request for.
791 * @mask: Flags to set/clear.
792 * @set: Whether to set or clear the flags (true means set).
793 */
794int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set)
795{
796 s32 value;
797 int ret;
798
799 pm_runtime_get_sync(dev);
800 mutex_lock(&dev_pm_qos_mtx);
801
802 if (IS_ERR_OR_NULL(dev->power.qos) || !dev->power.qos->flags_req) {
803 ret = -EINVAL;
804 goto out;
805 }
806
807 value = dev_pm_qos_requested_flags(dev);
808 if (set)
809 value |= mask;
810 else
811 value &= ~mask;
812
813 ret = __dev_pm_qos_update_request(dev->power.qos->flags_req, value);
814
815 out:
816 mutex_unlock(&dev_pm_qos_mtx);
817 pm_runtime_put(dev);
818 return ret;
819}
820
821/**
822 * dev_pm_qos_get_user_latency_tolerance - Get user space latency tolerance.
823 * @dev: Device to obtain the user space latency tolerance for.
824 */
825s32 dev_pm_qos_get_user_latency_tolerance(struct device *dev)
826{
827 s32 ret;
828
829 mutex_lock(&dev_pm_qos_mtx);
830 ret = IS_ERR_OR_NULL(dev->power.qos)
831 || !dev->power.qos->latency_tolerance_req ?
832 PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT :
833 dev->power.qos->latency_tolerance_req->data.pnode.prio;
834 mutex_unlock(&dev_pm_qos_mtx);
835 return ret;
836}
837
838/**
839 * dev_pm_qos_update_user_latency_tolerance - Update user space latency tolerance.
840 * @dev: Device to update the user space latency tolerance for.
841 * @val: New user space latency tolerance for @dev (negative values disable).
842 */
843int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val)
844{
845 int ret;
846
847 mutex_lock(&dev_pm_qos_mtx);
848
849 if (IS_ERR_OR_NULL(dev->power.qos)
850 || !dev->power.qos->latency_tolerance_req) {
851 struct dev_pm_qos_request *req;
852
853 if (val < 0) {
854 if (val == PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT)
855 ret = 0;
856 else
857 ret = -EINVAL;
858 goto out;
859 }
860 req = kzalloc(sizeof(*req), GFP_KERNEL);
861 if (!req) {
862 ret = -ENOMEM;
863 goto out;
864 }
865 ret = __dev_pm_qos_add_request(dev, req, DEV_PM_QOS_LATENCY_TOLERANCE, val);
866 if (ret < 0) {
867 kfree(req);
868 goto out;
869 }
870 dev->power.qos->latency_tolerance_req = req;
871 } else {
872 if (val < 0) {
873 __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY_TOLERANCE);
874 ret = 0;
875 } else {
876 ret = __dev_pm_qos_update_request(dev->power.qos->latency_tolerance_req, val);
877 }
878 }
879
880 out:
881 mutex_unlock(&dev_pm_qos_mtx);
882 return ret;
883}
884EXPORT_SYMBOL_GPL(dev_pm_qos_update_user_latency_tolerance);
885
886/**
887 * dev_pm_qos_expose_latency_tolerance - Expose latency tolerance to userspace
888 * @dev: Device whose latency tolerance to expose
889 */
890int dev_pm_qos_expose_latency_tolerance(struct device *dev)
891{
892 int ret;
893
894 if (!dev->power.set_latency_tolerance)
895 return -EINVAL;
896
897 mutex_lock(&dev_pm_qos_sysfs_mtx);
898 ret = pm_qos_sysfs_add_latency_tolerance(dev);
899 mutex_unlock(&dev_pm_qos_sysfs_mtx);
900
901 return ret;
902}
903EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_tolerance);
904
905/**
906 * dev_pm_qos_hide_latency_tolerance - Hide latency tolerance from userspace
907 * @dev: Device whose latency tolerance to hide
908 */
909void dev_pm_qos_hide_latency_tolerance(struct device *dev)
910{
911 mutex_lock(&dev_pm_qos_sysfs_mtx);
912 pm_qos_sysfs_remove_latency_tolerance(dev);
913 mutex_unlock(&dev_pm_qos_sysfs_mtx);
914
915 /* Remove the request from user space now */
916 pm_runtime_get_sync(dev);
917 dev_pm_qos_update_user_latency_tolerance(dev,
918 PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT);
919 pm_runtime_put(dev);
920}
921EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_tolerance);