Commit | Line | Data |
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91ff4cb8 JP |
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. | |
b66213cd JP |
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. | |
91ff4cb8 JP |
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. | |
91ff4cb8 JP |
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> | |
1b6bc32f | 42 | #include <linux/export.h> |
e39473d0 | 43 | #include <linux/pm_runtime.h> |
37530f2b | 44 | #include <linux/err.h> |
96d9d0b5 | 45 | #include <trace/events/power.h> |
91ff4cb8 | 46 | |
85dc0b8a | 47 | #include "power.h" |
91ff4cb8 JP |
48 | |
49 | static DEFINE_MUTEX(dev_pm_qos_mtx); | |
0f703069 | 50 | static DEFINE_MUTEX(dev_pm_qos_sysfs_mtx); |
1a9a9152 | 51 | |
b66213cd JP |
52 | static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers); |
53 | ||
ae0fb4b7 RW |
54 | /** |
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. | |
58 | * | |
59 | * This routine must be called with dev->power.lock held. | |
60 | */ | |
61 | enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask) | |
62 | { | |
63 | struct dev_pm_qos *qos = dev->power.qos; | |
64 | struct pm_qos_flags *pqf; | |
65 | s32 val; | |
66 | ||
f90b8ad8 KK |
67 | lockdep_assert_held(&dev->power.lock); |
68 | ||
37530f2b | 69 | if (IS_ERR_OR_NULL(qos)) |
ae0fb4b7 RW |
70 | return PM_QOS_FLAGS_UNDEFINED; |
71 | ||
72 | pqf = &qos->flags; | |
73 | if (list_empty(&pqf->list)) | |
74 | return PM_QOS_FLAGS_UNDEFINED; | |
75 | ||
76 | val = pqf->effective_flags & mask; | |
77 | if (val) | |
78 | return (val == mask) ? PM_QOS_FLAGS_ALL : PM_QOS_FLAGS_SOME; | |
79 | ||
80 | return PM_QOS_FLAGS_NONE; | |
81 | } | |
82 | ||
83 | /** | |
84 | * dev_pm_qos_flags - Check PM QoS flags for a given device (locked). | |
85 | * @dev: Device to check the PM QoS flags for. | |
86 | * @mask: Flags to check against. | |
87 | */ | |
88 | enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask) | |
89 | { | |
90 | unsigned long irqflags; | |
91 | enum pm_qos_flags_status ret; | |
92 | ||
93 | spin_lock_irqsave(&dev->power.lock, irqflags); | |
94 | ret = __dev_pm_qos_flags(dev, mask); | |
95 | spin_unlock_irqrestore(&dev->power.lock, irqflags); | |
96 | ||
97 | return ret; | |
98 | } | |
6802771b | 99 | EXPORT_SYMBOL_GPL(dev_pm_qos_flags); |
ae0fb4b7 | 100 | |
1a9a9152 | 101 | /** |
00dc9ad1 RW |
102 | * __dev_pm_qos_read_value - Get PM QoS constraint for a given device. |
103 | * @dev: Device to get the PM QoS constraint value for. | |
104 | * | |
105 | * This routine must be called with dev->power.lock held. | |
106 | */ | |
107 | s32 __dev_pm_qos_read_value(struct device *dev) | |
108 | { | |
f90b8ad8 KK |
109 | lockdep_assert_held(&dev->power.lock); |
110 | ||
37530f2b | 111 | return IS_ERR_OR_NULL(dev->power.qos) ? |
b02f6695 | 112 | 0 : pm_qos_read_value(&dev->power.qos->resume_latency); |
00dc9ad1 RW |
113 | } |
114 | ||
115 | /** | |
116 | * dev_pm_qos_read_value - Get PM QoS constraint for a given device (locked). | |
1a9a9152 RW |
117 | * @dev: Device to get the PM QoS constraint value for. |
118 | */ | |
119 | s32 dev_pm_qos_read_value(struct device *dev) | |
120 | { | |
1a9a9152 | 121 | unsigned long flags; |
00dc9ad1 | 122 | s32 ret; |
1a9a9152 RW |
123 | |
124 | spin_lock_irqsave(&dev->power.lock, flags); | |
00dc9ad1 | 125 | ret = __dev_pm_qos_read_value(dev); |
1a9a9152 RW |
126 | spin_unlock_irqrestore(&dev->power.lock, flags); |
127 | ||
128 | return ret; | |
129 | } | |
130 | ||
ae0fb4b7 RW |
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. | |
b66213cd JP |
136 | * |
137 | * Internal function to update the constraints list using the PM QoS core | |
138 | * code and if needed call the per-device and the global notification | |
139 | * callbacks | |
140 | */ | |
141 | static int apply_constraint(struct dev_pm_qos_request *req, | |
ae0fb4b7 | 142 | enum pm_qos_req_action action, s32 value) |
b66213cd | 143 | { |
ae0fb4b7 RW |
144 | struct dev_pm_qos *qos = req->dev->power.qos; |
145 | int ret; | |
b66213cd | 146 | |
ae0fb4b7 | 147 | switch(req->type) { |
b02f6695 RW |
148 | case DEV_PM_QOS_RESUME_LATENCY: |
149 | ret = pm_qos_update_target(&qos->resume_latency, | |
150 | &req->data.pnode, action, value); | |
ae0fb4b7 | 151 | if (ret) { |
b02f6695 | 152 | value = pm_qos_read_value(&qos->resume_latency); |
ae0fb4b7 RW |
153 | blocking_notifier_call_chain(&dev_pm_notifiers, |
154 | (unsigned long)value, | |
155 | req); | |
156 | } | |
157 | break; | |
2d984ad1 RW |
158 | case DEV_PM_QOS_LATENCY_TOLERANCE: |
159 | ret = pm_qos_update_target(&qos->latency_tolerance, | |
160 | &req->data.pnode, action, value); | |
161 | if (ret) { | |
162 | value = pm_qos_read_value(&qos->latency_tolerance); | |
163 | req->dev->power.set_latency_tolerance(req->dev, value); | |
164 | } | |
165 | break; | |
ae0fb4b7 RW |
166 | case DEV_PM_QOS_FLAGS: |
167 | ret = pm_qos_update_flags(&qos->flags, &req->data.flr, | |
168 | action, value); | |
169 | break; | |
170 | default: | |
171 | ret = -EINVAL; | |
b66213cd JP |
172 | } |
173 | ||
174 | return ret; | |
175 | } | |
91ff4cb8 JP |
176 | |
177 | /* | |
178 | * dev_pm_qos_constraints_allocate | |
179 | * @dev: device to allocate data for | |
180 | * | |
181 | * Called at the first call to add_request, for constraint data allocation | |
182 | * Must be called with the dev_pm_qos_mtx mutex held | |
183 | */ | |
184 | static int dev_pm_qos_constraints_allocate(struct device *dev) | |
185 | { | |
5f986c59 | 186 | struct dev_pm_qos *qos; |
91ff4cb8 JP |
187 | struct pm_qos_constraints *c; |
188 | struct blocking_notifier_head *n; | |
189 | ||
5f986c59 RW |
190 | qos = kzalloc(sizeof(*qos), GFP_KERNEL); |
191 | if (!qos) | |
91ff4cb8 JP |
192 | return -ENOMEM; |
193 | ||
194 | n = kzalloc(sizeof(*n), GFP_KERNEL); | |
195 | if (!n) { | |
5f986c59 | 196 | kfree(qos); |
91ff4cb8 JP |
197 | return -ENOMEM; |
198 | } | |
199 | BLOCKING_INIT_NOTIFIER_HEAD(n); | |
200 | ||
b02f6695 | 201 | c = &qos->resume_latency; |
1a9a9152 | 202 | plist_head_init(&c->list); |
b02f6695 RW |
203 | c->target_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE; |
204 | c->default_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE; | |
327adaed | 205 | c->no_constraint_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE; |
1a9a9152 RW |
206 | c->type = PM_QOS_MIN; |
207 | c->notifiers = n; | |
208 | ||
2d984ad1 RW |
209 | c = &qos->latency_tolerance; |
210 | plist_head_init(&c->list); | |
211 | c->target_value = PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE; | |
212 | c->default_value = PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE; | |
213 | c->no_constraint_value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT; | |
214 | c->type = PM_QOS_MIN; | |
215 | ||
ae0fb4b7 RW |
216 | INIT_LIST_HEAD(&qos->flags.list); |
217 | ||
1a9a9152 | 218 | spin_lock_irq(&dev->power.lock); |
5f986c59 | 219 | dev->power.qos = qos; |
1a9a9152 | 220 | spin_unlock_irq(&dev->power.lock); |
91ff4cb8 JP |
221 | |
222 | return 0; | |
223 | } | |
224 | ||
37530f2b RW |
225 | static void __dev_pm_qos_hide_latency_limit(struct device *dev); |
226 | static void __dev_pm_qos_hide_flags(struct device *dev); | |
91ff4cb8 JP |
227 | |
228 | /** | |
229 | * dev_pm_qos_constraints_destroy | |
230 | * @dev: target device | |
231 | * | |
1a9a9152 | 232 | * Called from the device PM subsystem on device removal under device_pm_lock(). |
91ff4cb8 JP |
233 | */ |
234 | void dev_pm_qos_constraints_destroy(struct device *dev) | |
235 | { | |
5f986c59 | 236 | struct dev_pm_qos *qos; |
91ff4cb8 | 237 | struct dev_pm_qos_request *req, *tmp; |
1a9a9152 | 238 | struct pm_qos_constraints *c; |
35546bd4 | 239 | struct pm_qos_flags *f; |
91ff4cb8 | 240 | |
0f703069 | 241 | mutex_lock(&dev_pm_qos_sysfs_mtx); |
37530f2b | 242 | |
85dc0b8a | 243 | /* |
35546bd4 RW |
244 | * If the device's PM QoS resume latency limit or PM QoS flags have been |
245 | * exposed to user space, they have to be hidden at this point. | |
85dc0b8a | 246 | */ |
b02f6695 | 247 | pm_qos_sysfs_remove_resume_latency(dev); |
0f703069 RW |
248 | pm_qos_sysfs_remove_flags(dev); |
249 | ||
250 | mutex_lock(&dev_pm_qos_mtx); | |
251 | ||
37530f2b RW |
252 | __dev_pm_qos_hide_latency_limit(dev); |
253 | __dev_pm_qos_hide_flags(dev); | |
91ff4cb8 | 254 | |
5f986c59 RW |
255 | qos = dev->power.qos; |
256 | if (!qos) | |
1a9a9152 | 257 | goto out; |
91ff4cb8 | 258 | |
35546bd4 | 259 | /* Flush the constraints lists for the device. */ |
b02f6695 | 260 | c = &qos->resume_latency; |
021c870b | 261 | plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) { |
1a9a9152 RW |
262 | /* |
263 | * Update constraints list and call the notification | |
264 | * callbacks if needed | |
265 | */ | |
266 | apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); | |
267 | memset(req, 0, sizeof(*req)); | |
91ff4cb8 | 268 | } |
2d984ad1 RW |
269 | c = &qos->latency_tolerance; |
270 | plist_for_each_entry_safe(req, tmp, &c->list, data.pnode) { | |
271 | apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); | |
272 | memset(req, 0, sizeof(*req)); | |
273 | } | |
35546bd4 RW |
274 | f = &qos->flags; |
275 | list_for_each_entry_safe(req, tmp, &f->list, data.flr.node) { | |
276 | apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); | |
277 | memset(req, 0, sizeof(*req)); | |
91ff4cb8 | 278 | } |
91ff4cb8 | 279 | |
1a9a9152 | 280 | spin_lock_irq(&dev->power.lock); |
37530f2b | 281 | dev->power.qos = ERR_PTR(-ENODEV); |
1a9a9152 RW |
282 | spin_unlock_irq(&dev->power.lock); |
283 | ||
284 | kfree(c->notifiers); | |
9eaee2cd | 285 | kfree(qos); |
1a9a9152 RW |
286 | |
287 | out: | |
91ff4cb8 | 288 | mutex_unlock(&dev_pm_qos_mtx); |
0f703069 RW |
289 | |
290 | mutex_unlock(&dev_pm_qos_sysfs_mtx); | |
91ff4cb8 JP |
291 | } |
292 | ||
2d984ad1 RW |
293 | static bool dev_pm_qos_invalid_request(struct device *dev, |
294 | struct dev_pm_qos_request *req) | |
295 | { | |
296 | return !req || (req->type == DEV_PM_QOS_LATENCY_TOLERANCE | |
297 | && !dev->power.set_latency_tolerance); | |
298 | } | |
299 | ||
300 | static int __dev_pm_qos_add_request(struct device *dev, | |
301 | struct dev_pm_qos_request *req, | |
302 | enum dev_pm_qos_req_type type, s32 value) | |
303 | { | |
304 | int ret = 0; | |
305 | ||
306 | if (!dev || dev_pm_qos_invalid_request(dev, req)) | |
307 | return -EINVAL; | |
308 | ||
309 | if (WARN(dev_pm_qos_request_active(req), | |
310 | "%s() called for already added request\n", __func__)) | |
311 | return -EINVAL; | |
312 | ||
313 | if (IS_ERR(dev->power.qos)) | |
314 | ret = -ENODEV; | |
315 | else if (!dev->power.qos) | |
316 | ret = dev_pm_qos_constraints_allocate(dev); | |
317 | ||
318 | trace_dev_pm_qos_add_request(dev_name(dev), type, value); | |
319 | if (!ret) { | |
320 | req->dev = dev; | |
321 | req->type = type; | |
322 | ret = apply_constraint(req, PM_QOS_ADD_REQ, value); | |
323 | } | |
324 | return ret; | |
325 | } | |
326 | ||
91ff4cb8 JP |
327 | /** |
328 | * dev_pm_qos_add_request - inserts new qos request into the list | |
329 | * @dev: target device for the constraint | |
330 | * @req: pointer to a preallocated handle | |
ae0fb4b7 | 331 | * @type: type of the request |
91ff4cb8 JP |
332 | * @value: defines the qos request |
333 | * | |
334 | * This function inserts a new entry in the device constraints list of | |
335 | * requested qos performance characteristics. It recomputes the aggregate | |
336 | * QoS expectations of parameters and initializes the dev_pm_qos_request | |
337 | * handle. Caller needs to save this handle for later use in updates and | |
338 | * removal. | |
339 | * | |
340 | * Returns 1 if the aggregated constraint value has changed, | |
341 | * 0 if the aggregated constraint value has not changed, | |
1a9a9152 RW |
342 | * -EINVAL in case of wrong parameters, -ENOMEM if there's not enough memory |
343 | * to allocate for data structures, -ENODEV if the device has just been removed | |
344 | * from the system. | |
436ede89 RW |
345 | * |
346 | * Callers should ensure that the target device is not RPM_SUSPENDED before | |
347 | * using this function for requests of type DEV_PM_QOS_FLAGS. | |
91ff4cb8 JP |
348 | */ |
349 | int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, | |
ae0fb4b7 | 350 | enum dev_pm_qos_req_type type, s32 value) |
91ff4cb8 | 351 | { |
2d984ad1 | 352 | int ret; |
91ff4cb8 | 353 | |
1a9a9152 | 354 | mutex_lock(&dev_pm_qos_mtx); |
2d984ad1 | 355 | ret = __dev_pm_qos_add_request(dev, req, type, value); |
91ff4cb8 JP |
356 | mutex_unlock(&dev_pm_qos_mtx); |
357 | return ret; | |
358 | } | |
359 | EXPORT_SYMBOL_GPL(dev_pm_qos_add_request); | |
360 | ||
e39473d0 RW |
361 | /** |
362 | * __dev_pm_qos_update_request - Modify an existing device PM QoS request. | |
363 | * @req : PM QoS request to modify. | |
364 | * @new_value: New value to request. | |
365 | */ | |
366 | static int __dev_pm_qos_update_request(struct dev_pm_qos_request *req, | |
367 | s32 new_value) | |
368 | { | |
369 | s32 curr_value; | |
370 | int ret = 0; | |
371 | ||
b81ea1b5 RW |
372 | if (!req) /*guard against callers passing in null */ |
373 | return -EINVAL; | |
374 | ||
375 | if (WARN(!dev_pm_qos_request_active(req), | |
376 | "%s() called for unknown object\n", __func__)) | |
377 | return -EINVAL; | |
378 | ||
37530f2b | 379 | if (IS_ERR_OR_NULL(req->dev->power.qos)) |
e39473d0 RW |
380 | return -ENODEV; |
381 | ||
382 | switch(req->type) { | |
b02f6695 | 383 | case DEV_PM_QOS_RESUME_LATENCY: |
2d984ad1 | 384 | case DEV_PM_QOS_LATENCY_TOLERANCE: |
e39473d0 RW |
385 | curr_value = req->data.pnode.prio; |
386 | break; | |
387 | case DEV_PM_QOS_FLAGS: | |
388 | curr_value = req->data.flr.flags; | |
389 | break; | |
390 | default: | |
391 | return -EINVAL; | |
392 | } | |
393 | ||
96d9d0b5 S |
394 | trace_dev_pm_qos_update_request(dev_name(req->dev), req->type, |
395 | new_value); | |
e39473d0 RW |
396 | if (curr_value != new_value) |
397 | ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value); | |
398 | ||
399 | return ret; | |
400 | } | |
401 | ||
91ff4cb8 JP |
402 | /** |
403 | * dev_pm_qos_update_request - modifies an existing qos request | |
404 | * @req : handle to list element holding a dev_pm_qos request to use | |
405 | * @new_value: defines the qos request | |
406 | * | |
407 | * Updates an existing dev PM qos request along with updating the | |
408 | * target value. | |
409 | * | |
410 | * Attempts are made to make this code callable on hot code paths. | |
411 | * | |
412 | * Returns 1 if the aggregated constraint value has changed, | |
413 | * 0 if the aggregated constraint value has not changed, | |
414 | * -EINVAL in case of wrong parameters, -ENODEV if the device has been | |
415 | * removed from the system | |
436ede89 RW |
416 | * |
417 | * Callers should ensure that the target device is not RPM_SUSPENDED before | |
418 | * using this function for requests of type DEV_PM_QOS_FLAGS. | |
91ff4cb8 | 419 | */ |
e39473d0 | 420 | int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value) |
91ff4cb8 | 421 | { |
e39473d0 | 422 | int ret; |
91ff4cb8 | 423 | |
b81ea1b5 RW |
424 | mutex_lock(&dev_pm_qos_mtx); |
425 | ret = __dev_pm_qos_update_request(req, new_value); | |
426 | mutex_unlock(&dev_pm_qos_mtx); | |
427 | return ret; | |
428 | } | |
429 | EXPORT_SYMBOL_GPL(dev_pm_qos_update_request); | |
430 | ||
431 | static int __dev_pm_qos_remove_request(struct dev_pm_qos_request *req) | |
432 | { | |
37530f2b | 433 | int ret; |
b81ea1b5 | 434 | |
91ff4cb8 JP |
435 | if (!req) /*guard against callers passing in null */ |
436 | return -EINVAL; | |
437 | ||
af4c720e GL |
438 | if (WARN(!dev_pm_qos_request_active(req), |
439 | "%s() called for unknown object\n", __func__)) | |
91ff4cb8 | 440 | return -EINVAL; |
91ff4cb8 | 441 | |
37530f2b RW |
442 | if (IS_ERR_OR_NULL(req->dev->power.qos)) |
443 | return -ENODEV; | |
444 | ||
96d9d0b5 S |
445 | trace_dev_pm_qos_remove_request(dev_name(req->dev), req->type, |
446 | PM_QOS_DEFAULT_VALUE); | |
37530f2b RW |
447 | ret = apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); |
448 | memset(req, 0, sizeof(*req)); | |
91ff4cb8 JP |
449 | return ret; |
450 | } | |
91ff4cb8 JP |
451 | |
452 | /** | |
453 | * dev_pm_qos_remove_request - modifies an existing qos request | |
454 | * @req: handle to request list element | |
455 | * | |
456 | * Will remove pm qos request from the list of constraints and | |
457 | * recompute the current target value. Call this on slow code paths. | |
458 | * | |
459 | * Returns 1 if the aggregated constraint value has changed, | |
460 | * 0 if the aggregated constraint value has not changed, | |
461 | * -EINVAL in case of wrong parameters, -ENODEV if the device has been | |
462 | * removed from the system | |
436ede89 RW |
463 | * |
464 | * Callers should ensure that the target device is not RPM_SUSPENDED before | |
465 | * using this function for requests of type DEV_PM_QOS_FLAGS. | |
91ff4cb8 JP |
466 | */ |
467 | int dev_pm_qos_remove_request(struct dev_pm_qos_request *req) | |
468 | { | |
b81ea1b5 | 469 | int ret; |
91ff4cb8 JP |
470 | |
471 | mutex_lock(&dev_pm_qos_mtx); | |
b81ea1b5 | 472 | ret = __dev_pm_qos_remove_request(req); |
91ff4cb8 JP |
473 | mutex_unlock(&dev_pm_qos_mtx); |
474 | return ret; | |
475 | } | |
476 | EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request); | |
477 | ||
478 | /** | |
479 | * dev_pm_qos_add_notifier - sets notification entry for changes to target value | |
480 | * of per-device PM QoS constraints | |
481 | * | |
482 | * @dev: target device for the constraint | |
483 | * @notifier: notifier block managed by caller. | |
484 | * | |
485 | * Will register the notifier into a notification chain that gets called | |
486 | * upon changes to the target value for the device. | |
23e0fc5a RW |
487 | * |
488 | * If the device's constraints object doesn't exist when this routine is called, | |
489 | * it will be created (or error code will be returned if that fails). | |
91ff4cb8 JP |
490 | */ |
491 | int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier) | |
492 | { | |
23e0fc5a | 493 | int ret = 0; |
91ff4cb8 JP |
494 | |
495 | mutex_lock(&dev_pm_qos_mtx); | |
496 | ||
37530f2b RW |
497 | if (IS_ERR(dev->power.qos)) |
498 | ret = -ENODEV; | |
499 | else if (!dev->power.qos) | |
500 | ret = dev_pm_qos_constraints_allocate(dev); | |
23e0fc5a RW |
501 | |
502 | if (!ret) | |
b02f6695 RW |
503 | ret = blocking_notifier_chain_register(dev->power.qos->resume_latency.notifiers, |
504 | notifier); | |
91ff4cb8 | 505 | |
91ff4cb8 | 506 | mutex_unlock(&dev_pm_qos_mtx); |
23e0fc5a | 507 | return ret; |
91ff4cb8 JP |
508 | } |
509 | EXPORT_SYMBOL_GPL(dev_pm_qos_add_notifier); | |
510 | ||
511 | /** | |
512 | * dev_pm_qos_remove_notifier - deletes notification for changes to target value | |
513 | * of per-device PM QoS constraints | |
514 | * | |
515 | * @dev: target device for the constraint | |
516 | * @notifier: notifier block to be removed. | |
517 | * | |
518 | * Will remove the notifier from the notification chain that gets called | |
519 | * upon changes to the target value. | |
520 | */ | |
521 | int dev_pm_qos_remove_notifier(struct device *dev, | |
522 | struct notifier_block *notifier) | |
523 | { | |
524 | int retval = 0; | |
525 | ||
526 | mutex_lock(&dev_pm_qos_mtx); | |
527 | ||
1a9a9152 | 528 | /* Silently return if the constraints object is not present. */ |
37530f2b | 529 | if (!IS_ERR_OR_NULL(dev->power.qos)) |
b02f6695 RW |
530 | retval = blocking_notifier_chain_unregister(dev->power.qos->resume_latency.notifiers, |
531 | notifier); | |
91ff4cb8 | 532 | |
91ff4cb8 JP |
533 | mutex_unlock(&dev_pm_qos_mtx); |
534 | return retval; | |
535 | } | |
536 | EXPORT_SYMBOL_GPL(dev_pm_qos_remove_notifier); | |
b66213cd JP |
537 | |
538 | /** | |
539 | * dev_pm_qos_add_global_notifier - sets notification entry for changes to | |
540 | * target value of the PM QoS constraints for any device | |
541 | * | |
542 | * @notifier: notifier block managed by caller. | |
543 | * | |
544 | * Will register the notifier into a notification chain that gets called | |
545 | * upon changes to the target value for any device. | |
546 | */ | |
547 | int dev_pm_qos_add_global_notifier(struct notifier_block *notifier) | |
548 | { | |
549 | return blocking_notifier_chain_register(&dev_pm_notifiers, notifier); | |
550 | } | |
551 | EXPORT_SYMBOL_GPL(dev_pm_qos_add_global_notifier); | |
552 | ||
553 | /** | |
554 | * dev_pm_qos_remove_global_notifier - deletes notification for changes to | |
555 | * target value of PM QoS constraints for any device | |
556 | * | |
557 | * @notifier: notifier block to be removed. | |
558 | * | |
559 | * Will remove the notifier from the notification chain that gets called | |
560 | * upon changes to the target value for any device. | |
561 | */ | |
562 | int dev_pm_qos_remove_global_notifier(struct notifier_block *notifier) | |
563 | { | |
564 | return blocking_notifier_chain_unregister(&dev_pm_notifiers, notifier); | |
565 | } | |
566 | EXPORT_SYMBOL_GPL(dev_pm_qos_remove_global_notifier); | |
40a5f8be RW |
567 | |
568 | /** | |
569 | * dev_pm_qos_add_ancestor_request - Add PM QoS request for device's ancestor. | |
570 | * @dev: Device whose ancestor to add the request for. | |
571 | * @req: Pointer to the preallocated handle. | |
71d821fd | 572 | * @type: Type of the request. |
40a5f8be RW |
573 | * @value: Constraint latency value. |
574 | */ | |
575 | int dev_pm_qos_add_ancestor_request(struct device *dev, | |
71d821fd RW |
576 | struct dev_pm_qos_request *req, |
577 | enum dev_pm_qos_req_type type, s32 value) | |
40a5f8be RW |
578 | { |
579 | struct device *ancestor = dev->parent; | |
4ce47802 | 580 | int ret = -ENODEV; |
40a5f8be | 581 | |
71d821fd RW |
582 | switch (type) { |
583 | case DEV_PM_QOS_RESUME_LATENCY: | |
584 | while (ancestor && !ancestor->power.ignore_children) | |
585 | ancestor = ancestor->parent; | |
40a5f8be | 586 | |
71d821fd RW |
587 | break; |
588 | case DEV_PM_QOS_LATENCY_TOLERANCE: | |
589 | while (ancestor && !ancestor->power.set_latency_tolerance) | |
590 | ancestor = ancestor->parent; | |
591 | ||
592 | break; | |
593 | default: | |
594 | ancestor = NULL; | |
595 | } | |
40a5f8be | 596 | if (ancestor) |
71d821fd | 597 | ret = dev_pm_qos_add_request(ancestor, req, type, value); |
40a5f8be | 598 | |
4ce47802 | 599 | if (ret < 0) |
40a5f8be RW |
600 | req->dev = NULL; |
601 | ||
4ce47802 | 602 | return ret; |
40a5f8be RW |
603 | } |
604 | EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request); | |
85dc0b8a | 605 | |
e39473d0 RW |
606 | static void __dev_pm_qos_drop_user_request(struct device *dev, |
607 | enum dev_pm_qos_req_type type) | |
85dc0b8a | 608 | { |
b81ea1b5 RW |
609 | struct dev_pm_qos_request *req = NULL; |
610 | ||
e39473d0 | 611 | switch(type) { |
b02f6695 RW |
612 | case DEV_PM_QOS_RESUME_LATENCY: |
613 | req = dev->power.qos->resume_latency_req; | |
614 | dev->power.qos->resume_latency_req = NULL; | |
e39473d0 | 615 | break; |
2d984ad1 RW |
616 | case DEV_PM_QOS_LATENCY_TOLERANCE: |
617 | req = dev->power.qos->latency_tolerance_req; | |
618 | dev->power.qos->latency_tolerance_req = NULL; | |
619 | break; | |
e39473d0 | 620 | case DEV_PM_QOS_FLAGS: |
b81ea1b5 | 621 | req = dev->power.qos->flags_req; |
e39473d0 RW |
622 | dev->power.qos->flags_req = NULL; |
623 | break; | |
624 | } | |
b81ea1b5 RW |
625 | __dev_pm_qos_remove_request(req); |
626 | kfree(req); | |
85dc0b8a RW |
627 | } |
628 | ||
0f703069 RW |
629 | static void dev_pm_qos_drop_user_request(struct device *dev, |
630 | enum dev_pm_qos_req_type type) | |
631 | { | |
632 | mutex_lock(&dev_pm_qos_mtx); | |
633 | __dev_pm_qos_drop_user_request(dev, type); | |
634 | mutex_unlock(&dev_pm_qos_mtx); | |
635 | } | |
636 | ||
85dc0b8a RW |
637 | /** |
638 | * dev_pm_qos_expose_latency_limit - Expose PM QoS latency limit to user space. | |
639 | * @dev: Device whose PM QoS latency limit is to be exposed to user space. | |
640 | * @value: Initial value of the latency limit. | |
641 | */ | |
642 | int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value) | |
643 | { | |
644 | struct dev_pm_qos_request *req; | |
645 | int ret; | |
646 | ||
647 | if (!device_is_registered(dev) || value < 0) | |
648 | return -EINVAL; | |
649 | ||
85dc0b8a RW |
650 | req = kzalloc(sizeof(*req), GFP_KERNEL); |
651 | if (!req) | |
652 | return -ENOMEM; | |
653 | ||
b02f6695 | 654 | ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_RESUME_LATENCY, value); |
b81ea1b5 RW |
655 | if (ret < 0) { |
656 | kfree(req); | |
85dc0b8a | 657 | return ret; |
b81ea1b5 RW |
658 | } |
659 | ||
0f703069 RW |
660 | mutex_lock(&dev_pm_qos_sysfs_mtx); |
661 | ||
b81ea1b5 RW |
662 | mutex_lock(&dev_pm_qos_mtx); |
663 | ||
37530f2b | 664 | if (IS_ERR_OR_NULL(dev->power.qos)) |
b81ea1b5 | 665 | ret = -ENODEV; |
b02f6695 | 666 | else if (dev->power.qos->resume_latency_req) |
b81ea1b5 RW |
667 | ret = -EEXIST; |
668 | ||
669 | if (ret < 0) { | |
670 | __dev_pm_qos_remove_request(req); | |
671 | kfree(req); | |
0f703069 | 672 | mutex_unlock(&dev_pm_qos_mtx); |
b81ea1b5 RW |
673 | goto out; |
674 | } | |
b02f6695 | 675 | dev->power.qos->resume_latency_req = req; |
0f703069 RW |
676 | |
677 | mutex_unlock(&dev_pm_qos_mtx); | |
678 | ||
b02f6695 | 679 | ret = pm_qos_sysfs_add_resume_latency(dev); |
85dc0b8a | 680 | if (ret) |
b02f6695 | 681 | dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_RESUME_LATENCY); |
85dc0b8a | 682 | |
b81ea1b5 | 683 | out: |
0f703069 | 684 | mutex_unlock(&dev_pm_qos_sysfs_mtx); |
85dc0b8a RW |
685 | return ret; |
686 | } | |
687 | EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_limit); | |
688 | ||
37530f2b RW |
689 | static void __dev_pm_qos_hide_latency_limit(struct device *dev) |
690 | { | |
b02f6695 RW |
691 | if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->resume_latency_req) |
692 | __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_RESUME_LATENCY); | |
37530f2b RW |
693 | } |
694 | ||
85dc0b8a RW |
695 | /** |
696 | * dev_pm_qos_hide_latency_limit - Hide PM QoS latency limit from user space. | |
697 | * @dev: Device whose PM QoS latency limit is to be hidden from user space. | |
698 | */ | |
699 | void dev_pm_qos_hide_latency_limit(struct device *dev) | |
700 | { | |
0f703069 RW |
701 | mutex_lock(&dev_pm_qos_sysfs_mtx); |
702 | ||
b02f6695 | 703 | pm_qos_sysfs_remove_resume_latency(dev); |
0f703069 | 704 | |
b81ea1b5 | 705 | mutex_lock(&dev_pm_qos_mtx); |
37530f2b | 706 | __dev_pm_qos_hide_latency_limit(dev); |
b81ea1b5 | 707 | mutex_unlock(&dev_pm_qos_mtx); |
0f703069 RW |
708 | |
709 | mutex_unlock(&dev_pm_qos_sysfs_mtx); | |
85dc0b8a RW |
710 | } |
711 | EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_limit); | |
e39473d0 RW |
712 | |
713 | /** | |
714 | * dev_pm_qos_expose_flags - Expose PM QoS flags of a device to user space. | |
715 | * @dev: Device whose PM QoS flags are to be exposed to user space. | |
716 | * @val: Initial values of the flags. | |
717 | */ | |
718 | int dev_pm_qos_expose_flags(struct device *dev, s32 val) | |
719 | { | |
720 | struct dev_pm_qos_request *req; | |
721 | int ret; | |
722 | ||
723 | if (!device_is_registered(dev)) | |
724 | return -EINVAL; | |
725 | ||
e39473d0 RW |
726 | req = kzalloc(sizeof(*req), GFP_KERNEL); |
727 | if (!req) | |
728 | return -ENOMEM; | |
729 | ||
730 | ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_FLAGS, val); | |
b81ea1b5 RW |
731 | if (ret < 0) { |
732 | kfree(req); | |
733 | return ret; | |
734 | } | |
735 | ||
736 | pm_runtime_get_sync(dev); | |
0f703069 RW |
737 | mutex_lock(&dev_pm_qos_sysfs_mtx); |
738 | ||
b81ea1b5 RW |
739 | mutex_lock(&dev_pm_qos_mtx); |
740 | ||
37530f2b | 741 | if (IS_ERR_OR_NULL(dev->power.qos)) |
b81ea1b5 RW |
742 | ret = -ENODEV; |
743 | else if (dev->power.qos->flags_req) | |
744 | ret = -EEXIST; | |
745 | ||
746 | if (ret < 0) { | |
747 | __dev_pm_qos_remove_request(req); | |
748 | kfree(req); | |
0f703069 | 749 | mutex_unlock(&dev_pm_qos_mtx); |
b81ea1b5 RW |
750 | goto out; |
751 | } | |
e39473d0 | 752 | dev->power.qos->flags_req = req; |
0f703069 RW |
753 | |
754 | mutex_unlock(&dev_pm_qos_mtx); | |
755 | ||
e39473d0 RW |
756 | ret = pm_qos_sysfs_add_flags(dev); |
757 | if (ret) | |
0f703069 | 758 | dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS); |
e39473d0 | 759 | |
b81ea1b5 | 760 | out: |
0f703069 | 761 | mutex_unlock(&dev_pm_qos_sysfs_mtx); |
7e4d6844 | 762 | pm_runtime_put(dev); |
e39473d0 RW |
763 | return ret; |
764 | } | |
765 | EXPORT_SYMBOL_GPL(dev_pm_qos_expose_flags); | |
766 | ||
37530f2b RW |
767 | static void __dev_pm_qos_hide_flags(struct device *dev) |
768 | { | |
0f703069 | 769 | if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->flags_req) |
37530f2b | 770 | __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS); |
37530f2b RW |
771 | } |
772 | ||
e39473d0 RW |
773 | /** |
774 | * dev_pm_qos_hide_flags - Hide PM QoS flags of a device from user space. | |
775 | * @dev: Device whose PM QoS flags are to be hidden from user space. | |
776 | */ | |
777 | void dev_pm_qos_hide_flags(struct device *dev) | |
778 | { | |
b81ea1b5 | 779 | pm_runtime_get_sync(dev); |
0f703069 RW |
780 | mutex_lock(&dev_pm_qos_sysfs_mtx); |
781 | ||
782 | pm_qos_sysfs_remove_flags(dev); | |
783 | ||
b81ea1b5 | 784 | mutex_lock(&dev_pm_qos_mtx); |
37530f2b | 785 | __dev_pm_qos_hide_flags(dev); |
b81ea1b5 | 786 | mutex_unlock(&dev_pm_qos_mtx); |
0f703069 RW |
787 | |
788 | mutex_unlock(&dev_pm_qos_sysfs_mtx); | |
b81ea1b5 | 789 | pm_runtime_put(dev); |
e39473d0 RW |
790 | } |
791 | EXPORT_SYMBOL_GPL(dev_pm_qos_hide_flags); | |
792 | ||
793 | /** | |
794 | * dev_pm_qos_update_flags - Update PM QoS flags request owned by user space. | |
795 | * @dev: Device to update the PM QoS flags request for. | |
796 | * @mask: Flags to set/clear. | |
797 | * @set: Whether to set or clear the flags (true means set). | |
798 | */ | |
799 | int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set) | |
800 | { | |
801 | s32 value; | |
802 | int ret; | |
803 | ||
e39473d0 RW |
804 | pm_runtime_get_sync(dev); |
805 | mutex_lock(&dev_pm_qos_mtx); | |
806 | ||
37530f2b | 807 | if (IS_ERR_OR_NULL(dev->power.qos) || !dev->power.qos->flags_req) { |
b81ea1b5 RW |
808 | ret = -EINVAL; |
809 | goto out; | |
810 | } | |
811 | ||
e39473d0 RW |
812 | value = dev_pm_qos_requested_flags(dev); |
813 | if (set) | |
814 | value |= mask; | |
815 | else | |
816 | value &= ~mask; | |
817 | ||
818 | ret = __dev_pm_qos_update_request(dev->power.qos->flags_req, value); | |
819 | ||
b81ea1b5 | 820 | out: |
e39473d0 RW |
821 | mutex_unlock(&dev_pm_qos_mtx); |
822 | pm_runtime_put(dev); | |
e39473d0 RW |
823 | return ret; |
824 | } | |
2d984ad1 RW |
825 | |
826 | /** | |
827 | * dev_pm_qos_get_user_latency_tolerance - Get user space latency tolerance. | |
828 | * @dev: Device to obtain the user space latency tolerance for. | |
829 | */ | |
830 | s32 dev_pm_qos_get_user_latency_tolerance(struct device *dev) | |
831 | { | |
832 | s32 ret; | |
833 | ||
834 | mutex_lock(&dev_pm_qos_mtx); | |
835 | ret = IS_ERR_OR_NULL(dev->power.qos) | |
836 | || !dev->power.qos->latency_tolerance_req ? | |
837 | PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT : | |
838 | dev->power.qos->latency_tolerance_req->data.pnode.prio; | |
839 | mutex_unlock(&dev_pm_qos_mtx); | |
840 | return ret; | |
841 | } | |
842 | ||
843 | /** | |
844 | * dev_pm_qos_update_user_latency_tolerance - Update user space latency tolerance. | |
845 | * @dev: Device to update the user space latency tolerance for. | |
846 | * @val: New user space latency tolerance for @dev (negative values disable). | |
847 | */ | |
848 | int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val) | |
849 | { | |
850 | int ret; | |
851 | ||
852 | mutex_lock(&dev_pm_qos_mtx); | |
853 | ||
854 | if (IS_ERR_OR_NULL(dev->power.qos) | |
855 | || !dev->power.qos->latency_tolerance_req) { | |
856 | struct dev_pm_qos_request *req; | |
857 | ||
858 | if (val < 0) { | |
859 | ret = -EINVAL; | |
860 | goto out; | |
861 | } | |
862 | req = kzalloc(sizeof(*req), GFP_KERNEL); | |
863 | if (!req) { | |
864 | ret = -ENOMEM; | |
865 | goto out; | |
866 | } | |
867 | ret = __dev_pm_qos_add_request(dev, req, DEV_PM_QOS_LATENCY_TOLERANCE, val); | |
868 | if (ret < 0) { | |
869 | kfree(req); | |
870 | goto out; | |
871 | } | |
872 | dev->power.qos->latency_tolerance_req = req; | |
873 | } else { | |
874 | if (val < 0) { | |
875 | __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY_TOLERANCE); | |
876 | ret = 0; | |
877 | } else { | |
878 | ret = __dev_pm_qos_update_request(dev->power.qos->latency_tolerance_req, val); | |
879 | } | |
880 | } | |
881 | ||
882 | out: | |
883 | mutex_unlock(&dev_pm_qos_mtx); | |
884 | return ret; | |
885 | } |