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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This module exposes the interface to kernel space for specifying
4 * QoS dependencies. It provides infrastructure for registration of:
5 *
6 * Dependents on a QoS value : register requests
7 * Watchers of QoS value : get notified when target QoS value changes
8 *
9 * This QoS design is best effort based. Dependents register their QoS needs.
10 * Watchers register to keep track of the current QoS needs of the system.
11 *
12 * There are 3 basic classes of QoS parameter: latency, timeout, throughput
13 * each have defined units:
14 * latency: usec
15 * timeout: usec <-- currently not used.
16 * throughput: kbs (kilo byte / sec)
17 *
18 * There are lists of pm_qos_objects each one wrapping requests, notifiers
19 *
20 * User mode requests on a QOS parameter register themselves to the
21 * subsystem by opening the device node /dev/... and writing there request to
22 * the node. As long as the process holds a file handle open to the node the
23 * client continues to be accounted for. Upon file release the usermode
24 * request is removed and a new qos target is computed. This way when the
25 * request that the application has is cleaned up when closes the file
26 * pointer or exits the pm_qos_object will get an opportunity to clean up.
27 *
28 * Mark Gross <mgross@linux.intel.com>
29 */
30
31/*#define DEBUG*/
32
33#include <linux/pm_qos.h>
34#include <linux/sched.h>
35#include <linux/spinlock.h>
36#include <linux/slab.h>
37#include <linux/time.h>
38#include <linux/fs.h>
39#include <linux/device.h>
40#include <linux/miscdevice.h>
41#include <linux/string.h>
42#include <linux/platform_device.h>
43#include <linux/init.h>
44#include <linux/kernel.h>
45#include <linux/debugfs.h>
46#include <linux/seq_file.h>
47
48#include <linux/uaccess.h>
49#include <linux/export.h>
50#include <trace/events/power.h>
51
52/*
53 * locking rule: all changes to constraints or notifiers lists
54 * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock
55 * held, taken with _irqsave. One lock to rule them all
56 */
57struct pm_qos_object {
58 struct pm_qos_constraints *constraints;
59 struct miscdevice pm_qos_power_miscdev;
60 char *name;
61};
62
63static DEFINE_SPINLOCK(pm_qos_lock);
64
65static struct pm_qos_object null_pm_qos;
66
67static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier);
68static struct pm_qos_constraints cpu_dma_constraints = {
69 .list = PLIST_HEAD_INIT(cpu_dma_constraints.list),
70 .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
71 .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
72 .no_constraint_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
73 .type = PM_QOS_MIN,
74 .notifiers = &cpu_dma_lat_notifier,
75};
76static struct pm_qos_object cpu_dma_pm_qos = {
77 .constraints = &cpu_dma_constraints,
78 .name = "cpu_dma_latency",
79};
80
81static struct pm_qos_object *pm_qos_array[] = {
82 &null_pm_qos,
83 &cpu_dma_pm_qos,
84};
85
86static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
87 size_t count, loff_t *f_pos);
88static ssize_t pm_qos_power_read(struct file *filp, char __user *buf,
89 size_t count, loff_t *f_pos);
90static int pm_qos_power_open(struct inode *inode, struct file *filp);
91static int pm_qos_power_release(struct inode *inode, struct file *filp);
92
93static const struct file_operations pm_qos_power_fops = {
94 .write = pm_qos_power_write,
95 .read = pm_qos_power_read,
96 .open = pm_qos_power_open,
97 .release = pm_qos_power_release,
98 .llseek = noop_llseek,
99};
100
101/* unlocked internal variant */
102static inline int pm_qos_get_value(struct pm_qos_constraints *c)
103{
104 struct plist_node *node;
105 int total_value = 0;
106
107 if (plist_head_empty(&c->list))
108 return c->no_constraint_value;
109
110 switch (c->type) {
111 case PM_QOS_MIN:
112 return plist_first(&c->list)->prio;
113
114 case PM_QOS_MAX:
115 return plist_last(&c->list)->prio;
116
117 case PM_QOS_SUM:
118 plist_for_each(node, &c->list)
119 total_value += node->prio;
120
121 return total_value;
122
123 default:
124 /* runtime check for not using enum */
125 BUG();
126 return PM_QOS_DEFAULT_VALUE;
127 }
128}
129
130s32 pm_qos_read_value(struct pm_qos_constraints *c)
131{
132 return c->target_value;
133}
134
135static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value)
136{
137 c->target_value = value;
138}
139
140static int pm_qos_debug_show(struct seq_file *s, void *unused)
141{
142 struct pm_qos_object *qos = (struct pm_qos_object *)s->private;
143 struct pm_qos_constraints *c;
144 struct pm_qos_request *req;
145 char *type;
146 unsigned long flags;
147 int tot_reqs = 0;
148 int active_reqs = 0;
149
150 if (IS_ERR_OR_NULL(qos)) {
151 pr_err("%s: bad qos param!\n", __func__);
152 return -EINVAL;
153 }
154 c = qos->constraints;
155 if (IS_ERR_OR_NULL(c)) {
156 pr_err("%s: Bad constraints on qos?\n", __func__);
157 return -EINVAL;
158 }
159
160 /* Lock to ensure we have a snapshot */
161 spin_lock_irqsave(&pm_qos_lock, flags);
162 if (plist_head_empty(&c->list)) {
163 seq_puts(s, "Empty!\n");
164 goto out;
165 }
166
167 switch (c->type) {
168 case PM_QOS_MIN:
169 type = "Minimum";
170 break;
171 case PM_QOS_MAX:
172 type = "Maximum";
173 break;
174 case PM_QOS_SUM:
175 type = "Sum";
176 break;
177 default:
178 type = "Unknown";
179 }
180
181 plist_for_each_entry(req, &c->list, node) {
182 char *state = "Default";
183
184 if ((req->node).prio != c->default_value) {
185 active_reqs++;
186 state = "Active";
187 }
188 tot_reqs++;
189 seq_printf(s, "%d: %d: %s\n", tot_reqs,
190 (req->node).prio, state);
191 }
192
193 seq_printf(s, "Type=%s, Value=%d, Requests: active=%d / total=%d\n",
194 type, pm_qos_get_value(c), active_reqs, tot_reqs);
195
196out:
197 spin_unlock_irqrestore(&pm_qos_lock, flags);
198 return 0;
199}
200
201DEFINE_SHOW_ATTRIBUTE(pm_qos_debug);
202
203/**
204 * pm_qos_update_target - manages the constraints list and calls the notifiers
205 * if needed
206 * @c: constraints data struct
207 * @node: request to add to the list, to update or to remove
208 * @action: action to take on the constraints list
209 * @value: value of the request to add or update
210 *
211 * This function returns 1 if the aggregated constraint value has changed, 0
212 * otherwise.
213 */
214int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
215 enum pm_qos_req_action action, int value)
216{
217 unsigned long flags;
218 int prev_value, curr_value, new_value;
219 int ret;
220
221 spin_lock_irqsave(&pm_qos_lock, flags);
222 prev_value = pm_qos_get_value(c);
223 if (value == PM_QOS_DEFAULT_VALUE)
224 new_value = c->default_value;
225 else
226 new_value = value;
227
228 switch (action) {
229 case PM_QOS_REMOVE_REQ:
230 plist_del(node, &c->list);
231 break;
232 case PM_QOS_UPDATE_REQ:
233 /*
234 * to change the list, we atomically remove, reinit
235 * with new value and add, then see if the extremal
236 * changed
237 */
238 plist_del(node, &c->list);
239 /* fall through */
240 case PM_QOS_ADD_REQ:
241 plist_node_init(node, new_value);
242 plist_add(node, &c->list);
243 break;
244 default:
245 /* no action */
246 ;
247 }
248
249 curr_value = pm_qos_get_value(c);
250 pm_qos_set_value(c, curr_value);
251
252 spin_unlock_irqrestore(&pm_qos_lock, flags);
253
254 trace_pm_qos_update_target(action, prev_value, curr_value);
255 if (prev_value != curr_value) {
256 ret = 1;
257 if (c->notifiers)
258 blocking_notifier_call_chain(c->notifiers,
259 (unsigned long)curr_value,
260 NULL);
261 } else {
262 ret = 0;
263 }
264 return ret;
265}
266
267/**
268 * pm_qos_flags_remove_req - Remove device PM QoS flags request.
269 * @pqf: Device PM QoS flags set to remove the request from.
270 * @req: Request to remove from the set.
271 */
272static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf,
273 struct pm_qos_flags_request *req)
274{
275 s32 val = 0;
276
277 list_del(&req->node);
278 list_for_each_entry(req, &pqf->list, node)
279 val |= req->flags;
280
281 pqf->effective_flags = val;
282}
283
284/**
285 * pm_qos_update_flags - Update a set of PM QoS flags.
286 * @pqf: Set of flags to update.
287 * @req: Request to add to the set, to modify, or to remove from the set.
288 * @action: Action to take on the set.
289 * @val: Value of the request to add or modify.
290 *
291 * Update the given set of PM QoS flags and call notifiers if the aggregate
292 * value has changed. Returns 1 if the aggregate constraint value has changed,
293 * 0 otherwise.
294 */
295bool pm_qos_update_flags(struct pm_qos_flags *pqf,
296 struct pm_qos_flags_request *req,
297 enum pm_qos_req_action action, s32 val)
298{
299 unsigned long irqflags;
300 s32 prev_value, curr_value;
301
302 spin_lock_irqsave(&pm_qos_lock, irqflags);
303
304 prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
305
306 switch (action) {
307 case PM_QOS_REMOVE_REQ:
308 pm_qos_flags_remove_req(pqf, req);
309 break;
310 case PM_QOS_UPDATE_REQ:
311 pm_qos_flags_remove_req(pqf, req);
312 /* fall through */
313 case PM_QOS_ADD_REQ:
314 req->flags = val;
315 INIT_LIST_HEAD(&req->node);
316 list_add_tail(&req->node, &pqf->list);
317 pqf->effective_flags |= val;
318 break;
319 default:
320 /* no action */
321 ;
322 }
323
324 curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
325
326 spin_unlock_irqrestore(&pm_qos_lock, irqflags);
327
328 trace_pm_qos_update_flags(action, prev_value, curr_value);
329 return prev_value != curr_value;
330}
331
332/**
333 * pm_qos_request - returns current system wide qos expectation
334 * @pm_qos_class: identification of which qos value is requested
335 *
336 * This function returns the current target value.
337 */
338int pm_qos_request(int pm_qos_class)
339{
340 return pm_qos_read_value(pm_qos_array[pm_qos_class]->constraints);
341}
342EXPORT_SYMBOL_GPL(pm_qos_request);
343
344int pm_qos_request_active(struct pm_qos_request *req)
345{
346 return req->pm_qos_class != 0;
347}
348EXPORT_SYMBOL_GPL(pm_qos_request_active);
349
350static void __pm_qos_update_request(struct pm_qos_request *req,
351 s32 new_value)
352{
353 trace_pm_qos_update_request(req->pm_qos_class, new_value);
354
355 if (new_value != req->node.prio)
356 pm_qos_update_target(
357 pm_qos_array[req->pm_qos_class]->constraints,
358 &req->node, PM_QOS_UPDATE_REQ, new_value);
359}
360
361/**
362 * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout
363 * @work: work struct for the delayed work (timeout)
364 *
365 * This cancels the timeout request by falling back to the default at timeout.
366 */
367static void pm_qos_work_fn(struct work_struct *work)
368{
369 struct pm_qos_request *req = container_of(to_delayed_work(work),
370 struct pm_qos_request,
371 work);
372
373 __pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE);
374}
375
376/**
377 * pm_qos_add_request - inserts new qos request into the list
378 * @req: pointer to a preallocated handle
379 * @pm_qos_class: identifies which list of qos request to use
380 * @value: defines the qos request
381 *
382 * This function inserts a new entry in the pm_qos_class list of requested qos
383 * performance characteristics. It recomputes the aggregate QoS expectations
384 * for the pm_qos_class of parameters and initializes the pm_qos_request
385 * handle. Caller needs to save this handle for later use in updates and
386 * removal.
387 */
388
389void pm_qos_add_request(struct pm_qos_request *req,
390 int pm_qos_class, s32 value)
391{
392 if (!req) /*guard against callers passing in null */
393 return;
394
395 if (pm_qos_request_active(req)) {
396 WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n");
397 return;
398 }
399 req->pm_qos_class = pm_qos_class;
400 INIT_DELAYED_WORK(&req->work, pm_qos_work_fn);
401 trace_pm_qos_add_request(pm_qos_class, value);
402 pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints,
403 &req->node, PM_QOS_ADD_REQ, value);
404}
405EXPORT_SYMBOL_GPL(pm_qos_add_request);
406
407/**
408 * pm_qos_update_request - modifies an existing qos request
409 * @req : handle to list element holding a pm_qos request to use
410 * @value: defines the qos request
411 *
412 * Updates an existing qos request for the pm_qos_class of parameters along
413 * with updating the target pm_qos_class value.
414 *
415 * Attempts are made to make this code callable on hot code paths.
416 */
417void pm_qos_update_request(struct pm_qos_request *req,
418 s32 new_value)
419{
420 if (!req) /*guard against callers passing in null */
421 return;
422
423 if (!pm_qos_request_active(req)) {
424 WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n");
425 return;
426 }
427
428 cancel_delayed_work_sync(&req->work);
429 __pm_qos_update_request(req, new_value);
430}
431EXPORT_SYMBOL_GPL(pm_qos_update_request);
432
433/**
434 * pm_qos_update_request_timeout - modifies an existing qos request temporarily.
435 * @req : handle to list element holding a pm_qos request to use
436 * @new_value: defines the temporal qos request
437 * @timeout_us: the effective duration of this qos request in usecs.
438 *
439 * After timeout_us, this qos request is cancelled automatically.
440 */
441void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value,
442 unsigned long timeout_us)
443{
444 if (!req)
445 return;
446 if (WARN(!pm_qos_request_active(req),
447 "%s called for unknown object.", __func__))
448 return;
449
450 cancel_delayed_work_sync(&req->work);
451
452 trace_pm_qos_update_request_timeout(req->pm_qos_class,
453 new_value, timeout_us);
454 if (new_value != req->node.prio)
455 pm_qos_update_target(
456 pm_qos_array[req->pm_qos_class]->constraints,
457 &req->node, PM_QOS_UPDATE_REQ, new_value);
458
459 schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us));
460}
461
462/**
463 * pm_qos_remove_request - modifies an existing qos request
464 * @req: handle to request list element
465 *
466 * Will remove pm qos request from the list of constraints and
467 * recompute the current target value for the pm_qos_class. Call this
468 * on slow code paths.
469 */
470void pm_qos_remove_request(struct pm_qos_request *req)
471{
472 if (!req) /*guard against callers passing in null */
473 return;
474 /* silent return to keep pcm code cleaner */
475
476 if (!pm_qos_request_active(req)) {
477 WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n");
478 return;
479 }
480
481 cancel_delayed_work_sync(&req->work);
482
483 trace_pm_qos_remove_request(req->pm_qos_class, PM_QOS_DEFAULT_VALUE);
484 pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints,
485 &req->node, PM_QOS_REMOVE_REQ,
486 PM_QOS_DEFAULT_VALUE);
487 memset(req, 0, sizeof(*req));
488}
489EXPORT_SYMBOL_GPL(pm_qos_remove_request);
490
491/**
492 * pm_qos_add_notifier - sets notification entry for changes to target value
493 * @pm_qos_class: identifies which qos target changes should be notified.
494 * @notifier: notifier block managed by caller.
495 *
496 * will register the notifier into a notification chain that gets called
497 * upon changes to the pm_qos_class target value.
498 */
499int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier)
500{
501 int retval;
502
503 retval = blocking_notifier_chain_register(
504 pm_qos_array[pm_qos_class]->constraints->notifiers,
505 notifier);
506
507 return retval;
508}
509EXPORT_SYMBOL_GPL(pm_qos_add_notifier);
510
511/**
512 * pm_qos_remove_notifier - deletes notification entry from chain.
513 * @pm_qos_class: identifies which qos target changes are notified.
514 * @notifier: notifier block to be removed.
515 *
516 * will remove the notifier from the notification chain that gets called
517 * upon changes to the pm_qos_class target value.
518 */
519int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
520{
521 int retval;
522
523 retval = blocking_notifier_chain_unregister(
524 pm_qos_array[pm_qos_class]->constraints->notifiers,
525 notifier);
526
527 return retval;
528}
529EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
530
531/* User space interface to PM QoS classes via misc devices */
532static int register_pm_qos_misc(struct pm_qos_object *qos, struct dentry *d)
533{
534 qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR;
535 qos->pm_qos_power_miscdev.name = qos->name;
536 qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops;
537
538 debugfs_create_file(qos->name, S_IRUGO, d, (void *)qos,
539 &pm_qos_debug_fops);
540
541 return misc_register(&qos->pm_qos_power_miscdev);
542}
543
544static int find_pm_qos_object_by_minor(int minor)
545{
546 int pm_qos_class;
547
548 for (pm_qos_class = PM_QOS_CPU_DMA_LATENCY;
549 pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) {
550 if (minor ==
551 pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor)
552 return pm_qos_class;
553 }
554 return -1;
555}
556
557static int pm_qos_power_open(struct inode *inode, struct file *filp)
558{
559 long pm_qos_class;
560
561 pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
562 if (pm_qos_class >= PM_QOS_CPU_DMA_LATENCY) {
563 struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL);
564 if (!req)
565 return -ENOMEM;
566
567 pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE);
568 filp->private_data = req;
569
570 return 0;
571 }
572 return -EPERM;
573}
574
575static int pm_qos_power_release(struct inode *inode, struct file *filp)
576{
577 struct pm_qos_request *req;
578
579 req = filp->private_data;
580 pm_qos_remove_request(req);
581 kfree(req);
582
583 return 0;
584}
585
586
587static ssize_t pm_qos_power_read(struct file *filp, char __user *buf,
588 size_t count, loff_t *f_pos)
589{
590 s32 value;
591 unsigned long flags;
592 struct pm_qos_request *req = filp->private_data;
593
594 if (!req)
595 return -EINVAL;
596 if (!pm_qos_request_active(req))
597 return -EINVAL;
598
599 spin_lock_irqsave(&pm_qos_lock, flags);
600 value = pm_qos_get_value(pm_qos_array[req->pm_qos_class]->constraints);
601 spin_unlock_irqrestore(&pm_qos_lock, flags);
602
603 return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32));
604}
605
606static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
607 size_t count, loff_t *f_pos)
608{
609 s32 value;
610 struct pm_qos_request *req;
611
612 if (count == sizeof(s32)) {
613 if (copy_from_user(&value, buf, sizeof(s32)))
614 return -EFAULT;
615 } else {
616 int ret;
617
618 ret = kstrtos32_from_user(buf, count, 16, &value);
619 if (ret)
620 return ret;
621 }
622
623 req = filp->private_data;
624 pm_qos_update_request(req, value);
625
626 return count;
627}
628
629
630static int __init pm_qos_power_init(void)
631{
632 int ret = 0;
633 int i;
634 struct dentry *d;
635
636 BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES);
637
638 d = debugfs_create_dir("pm_qos", NULL);
639
640 for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) {
641 ret = register_pm_qos_misc(pm_qos_array[i], d);
642 if (ret < 0) {
643 pr_err("%s: %s setup failed\n",
644 __func__, pm_qos_array[i]->name);
645 return ret;
646 }
647 }
648
649 return ret;
650}
651
652late_initcall(pm_qos_power_init);
653
654/* Definitions related to the frequency QoS below. */
655
656/**
657 * freq_constraints_init - Initialize frequency QoS constraints.
658 * @qos: Frequency QoS constraints to initialize.
659 */
660void freq_constraints_init(struct freq_constraints *qos)
661{
662 struct pm_qos_constraints *c;
663
664 c = &qos->min_freq;
665 plist_head_init(&c->list);
666 c->target_value = FREQ_QOS_MIN_DEFAULT_VALUE;
667 c->default_value = FREQ_QOS_MIN_DEFAULT_VALUE;
668 c->no_constraint_value = FREQ_QOS_MIN_DEFAULT_VALUE;
669 c->type = PM_QOS_MAX;
670 c->notifiers = &qos->min_freq_notifiers;
671 BLOCKING_INIT_NOTIFIER_HEAD(c->notifiers);
672
673 c = &qos->max_freq;
674 plist_head_init(&c->list);
675 c->target_value = FREQ_QOS_MAX_DEFAULT_VALUE;
676 c->default_value = FREQ_QOS_MAX_DEFAULT_VALUE;
677 c->no_constraint_value = FREQ_QOS_MAX_DEFAULT_VALUE;
678 c->type = PM_QOS_MIN;
679 c->notifiers = &qos->max_freq_notifiers;
680 BLOCKING_INIT_NOTIFIER_HEAD(c->notifiers);
681}
682
683/**
684 * freq_qos_read_value - Get frequency QoS constraint for a given list.
685 * @qos: Constraints to evaluate.
686 * @type: QoS request type.
687 */
688s32 freq_qos_read_value(struct freq_constraints *qos,
689 enum freq_qos_req_type type)
690{
691 s32 ret;
692
693 switch (type) {
694 case FREQ_QOS_MIN:
695 ret = IS_ERR_OR_NULL(qos) ?
696 FREQ_QOS_MIN_DEFAULT_VALUE :
697 pm_qos_read_value(&qos->min_freq);
698 break;
699 case FREQ_QOS_MAX:
700 ret = IS_ERR_OR_NULL(qos) ?
701 FREQ_QOS_MAX_DEFAULT_VALUE :
702 pm_qos_read_value(&qos->max_freq);
703 break;
704 default:
705 WARN_ON(1);
706 ret = 0;
707 }
708
709 return ret;
710}
711
712/**
713 * freq_qos_apply - Add/modify/remove frequency QoS request.
714 * @req: Constraint request to apply.
715 * @action: Action to perform (add/update/remove).
716 * @value: Value to assign to the QoS request.
717 */
718static int freq_qos_apply(struct freq_qos_request *req,
719 enum pm_qos_req_action action, s32 value)
720{
721 int ret;
722
723 switch(req->type) {
724 case FREQ_QOS_MIN:
725 ret = pm_qos_update_target(&req->qos->min_freq, &req->pnode,
726 action, value);
727 break;
728 case FREQ_QOS_MAX:
729 ret = pm_qos_update_target(&req->qos->max_freq, &req->pnode,
730 action, value);
731 break;
732 default:
733 ret = -EINVAL;
734 }
735
736 return ret;
737}
738
739/**
740 * freq_qos_add_request - Insert new frequency QoS request into a given list.
741 * @qos: Constraints to update.
742 * @req: Preallocated request object.
743 * @type: Request type.
744 * @value: Request value.
745 *
746 * Insert a new entry into the @qos list of requests, recompute the effective
747 * QoS constraint value for that list and initialize the @req object. The
748 * caller needs to save that object for later use in updates and removal.
749 *
750 * Return 1 if the effective constraint value has changed, 0 if the effective
751 * constraint value has not changed, or a negative error code on failures.
752 */
753int freq_qos_add_request(struct freq_constraints *qos,
754 struct freq_qos_request *req,
755 enum freq_qos_req_type type, s32 value)
756{
757 int ret;
758
759 if (IS_ERR_OR_NULL(qos) || !req)
760 return -EINVAL;
761
762 if (WARN(freq_qos_request_active(req),
763 "%s() called for active request\n", __func__))
764 return -EINVAL;
765
766 req->qos = qos;
767 req->type = type;
768 ret = freq_qos_apply(req, PM_QOS_ADD_REQ, value);
769 if (ret < 0) {
770 req->qos = NULL;
771 req->type = 0;
772 }
773
774 return ret;
775}
776EXPORT_SYMBOL_GPL(freq_qos_add_request);
777
778/**
779 * freq_qos_update_request - Modify existing frequency QoS request.
780 * @req: Request to modify.
781 * @new_value: New request value.
782 *
783 * Update an existing frequency QoS request along with the effective constraint
784 * value for the list of requests it belongs to.
785 *
786 * Return 1 if the effective constraint value has changed, 0 if the effective
787 * constraint value has not changed, or a negative error code on failures.
788 */
789int freq_qos_update_request(struct freq_qos_request *req, s32 new_value)
790{
791 if (!req)
792 return -EINVAL;
793
794 if (WARN(!freq_qos_request_active(req),
795 "%s() called for unknown object\n", __func__))
796 return -EINVAL;
797
798 if (req->pnode.prio == new_value)
799 return 0;
800
801 return freq_qos_apply(req, PM_QOS_UPDATE_REQ, new_value);
802}
803EXPORT_SYMBOL_GPL(freq_qos_update_request);
804
805/**
806 * freq_qos_remove_request - Remove frequency QoS request from its list.
807 * @req: Request to remove.
808 *
809 * Remove the given frequency QoS request from the list of constraints it
810 * belongs to and recompute the effective constraint value for that list.
811 *
812 * Return 1 if the effective constraint value has changed, 0 if the effective
813 * constraint value has not changed, or a negative error code on failures.
814 */
815int freq_qos_remove_request(struct freq_qos_request *req)
816{
817 int ret;
818
819 if (!req)
820 return -EINVAL;
821
822 if (WARN(!freq_qos_request_active(req),
823 "%s() called for unknown object\n", __func__))
824 return -EINVAL;
825
826 ret = freq_qos_apply(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
827 req->qos = NULL;
828 req->type = 0;
829
830 return ret;
831}
832EXPORT_SYMBOL_GPL(freq_qos_remove_request);
833
834/**
835 * freq_qos_add_notifier - Add frequency QoS change notifier.
836 * @qos: List of requests to add the notifier to.
837 * @type: Request type.
838 * @notifier: Notifier block to add.
839 */
840int freq_qos_add_notifier(struct freq_constraints *qos,
841 enum freq_qos_req_type type,
842 struct notifier_block *notifier)
843{
844 int ret;
845
846 if (IS_ERR_OR_NULL(qos) || !notifier)
847 return -EINVAL;
848
849 switch (type) {
850 case FREQ_QOS_MIN:
851 ret = blocking_notifier_chain_register(qos->min_freq.notifiers,
852 notifier);
853 break;
854 case FREQ_QOS_MAX:
855 ret = blocking_notifier_chain_register(qos->max_freq.notifiers,
856 notifier);
857 break;
858 default:
859 WARN_ON(1);
860 ret = -EINVAL;
861 }
862
863 return ret;
864}
865EXPORT_SYMBOL_GPL(freq_qos_add_notifier);
866
867/**
868 * freq_qos_remove_notifier - Remove frequency QoS change notifier.
869 * @qos: List of requests to remove the notifier from.
870 * @type: Request type.
871 * @notifier: Notifier block to remove.
872 */
873int freq_qos_remove_notifier(struct freq_constraints *qos,
874 enum freq_qos_req_type type,
875 struct notifier_block *notifier)
876{
877 int ret;
878
879 if (IS_ERR_OR_NULL(qos) || !notifier)
880 return -EINVAL;
881
882 switch (type) {
883 case FREQ_QOS_MIN:
884 ret = blocking_notifier_chain_unregister(qos->min_freq.notifiers,
885 notifier);
886 break;
887 case FREQ_QOS_MAX:
888 ret = blocking_notifier_chain_unregister(qos->max_freq.notifiers,
889 notifier);
890 break;
891 default:
892 WARN_ON(1);
893 ret = -EINVAL;
894 }
895
896 return ret;
897}
898EXPORT_SYMBOL_GPL(freq_qos_remove_notifier);