Commit | Line | Data |
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d82b3518 MG |
1 | /* |
2 | * This module exposes the interface to kernel space for specifying | |
3 | * QoS dependencies. It provides infrastructure for registration of: | |
4 | * | |
ed77134b | 5 | * Dependents on a QoS value : register requests |
d82b3518 MG |
6 | * Watchers of QoS value : get notified when target QoS value changes |
7 | * | |
8 | * This QoS design is best effort based. Dependents register their QoS needs. | |
9 | * Watchers register to keep track of the current QoS needs of the system. | |
10 | * | |
11 | * There are 3 basic classes of QoS parameter: latency, timeout, throughput | |
12 | * each have defined units: | |
13 | * latency: usec | |
14 | * timeout: usec <-- currently not used. | |
15 | * throughput: kbs (kilo byte / sec) | |
16 | * | |
ed77134b | 17 | * There are lists of pm_qos_objects each one wrapping requests, notifiers |
d82b3518 | 18 | * |
ed77134b | 19 | * User mode requests on a QOS parameter register themselves to the |
d82b3518 MG |
20 | * subsystem by opening the device node /dev/... and writing there request to |
21 | * the node. As long as the process holds a file handle open to the node the | |
22 | * client continues to be accounted for. Upon file release the usermode | |
ed77134b MG |
23 | * request is removed and a new qos target is computed. This way when the |
24 | * request that the application has is cleaned up when closes the file | |
d82b3518 MG |
25 | * pointer or exits the pm_qos_object will get an opportunity to clean up. |
26 | * | |
bf1db69f | 27 | * Mark Gross <mgross@linux.intel.com> |
d82b3518 MG |
28 | */ |
29 | ||
ed77134b MG |
30 | /*#define DEBUG*/ |
31 | ||
e8db0be1 | 32 | #include <linux/pm_qos.h> |
d82b3518 MG |
33 | #include <linux/sched.h> |
34 | #include <linux/spinlock.h> | |
35 | #include <linux/slab.h> | |
36 | #include <linux/time.h> | |
37 | #include <linux/fs.h> | |
38 | #include <linux/device.h> | |
39 | #include <linux/miscdevice.h> | |
40 | #include <linux/string.h> | |
41 | #include <linux/platform_device.h> | |
42 | #include <linux/init.h> | |
0775a60a | 43 | #include <linux/kernel.h> |
d82b3518 MG |
44 | |
45 | #include <linux/uaccess.h> | |
6e5fdeed | 46 | #include <linux/export.h> |
247e9ee0 | 47 | #include <trace/events/power.h> |
d82b3518 MG |
48 | |
49 | /* | |
cc749986 | 50 | * locking rule: all changes to constraints or notifiers lists |
d82b3518 MG |
51 | * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock |
52 | * held, taken with _irqsave. One lock to rule them all | |
53 | */ | |
d82b3518 | 54 | struct pm_qos_object { |
4e1779ba | 55 | struct pm_qos_constraints *constraints; |
d82b3518 MG |
56 | struct miscdevice pm_qos_power_miscdev; |
57 | char *name; | |
d82b3518 MG |
58 | }; |
59 | ||
5f279845 JB |
60 | static DEFINE_SPINLOCK(pm_qos_lock); |
61 | ||
d82b3518 | 62 | static struct pm_qos_object null_pm_qos; |
4e1779ba | 63 | |
d82b3518 | 64 | static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); |
4e1779ba JP |
65 | static struct pm_qos_constraints cpu_dma_constraints = { |
66 | .list = PLIST_HEAD_INIT(cpu_dma_constraints.list), | |
333c5ae9 TC |
67 | .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, |
68 | .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, | |
327adaed | 69 | .no_constraint_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, |
5f279845 | 70 | .type = PM_QOS_MIN, |
4e1779ba JP |
71 | .notifiers = &cpu_dma_lat_notifier, |
72 | }; | |
73 | static struct pm_qos_object cpu_dma_pm_qos = { | |
74 | .constraints = &cpu_dma_constraints, | |
a6f05b97 | 75 | .name = "cpu_dma_latency", |
d82b3518 MG |
76 | }; |
77 | ||
78 | static BLOCKING_NOTIFIER_HEAD(network_lat_notifier); | |
4e1779ba JP |
79 | static struct pm_qos_constraints network_lat_constraints = { |
80 | .list = PLIST_HEAD_INIT(network_lat_constraints.list), | |
333c5ae9 TC |
81 | .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, |
82 | .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, | |
327adaed | 83 | .no_constraint_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, |
4e1779ba JP |
84 | .type = PM_QOS_MIN, |
85 | .notifiers = &network_lat_notifier, | |
86 | }; | |
87 | static struct pm_qos_object network_lat_pm_qos = { | |
88 | .constraints = &network_lat_constraints, | |
89 | .name = "network_latency", | |
d82b3518 MG |
90 | }; |
91 | ||
92 | ||
93 | static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier); | |
4e1779ba JP |
94 | static struct pm_qos_constraints network_tput_constraints = { |
95 | .list = PLIST_HEAD_INIT(network_tput_constraints.list), | |
333c5ae9 TC |
96 | .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, |
97 | .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, | |
327adaed | 98 | .no_constraint_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, |
5f279845 | 99 | .type = PM_QOS_MAX, |
4e1779ba JP |
100 | .notifiers = &network_throughput_notifier, |
101 | }; | |
102 | static struct pm_qos_object network_throughput_pm_qos = { | |
103 | .constraints = &network_tput_constraints, | |
104 | .name = "network_throughput", | |
d82b3518 MG |
105 | }; |
106 | ||
107 | ||
108 | static struct pm_qos_object *pm_qos_array[] = { | |
109 | &null_pm_qos, | |
110 | &cpu_dma_pm_qos, | |
111 | &network_lat_pm_qos, | |
112 | &network_throughput_pm_qos | |
113 | }; | |
114 | ||
d82b3518 MG |
115 | static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, |
116 | size_t count, loff_t *f_pos); | |
f9b9e806 TR |
117 | static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, |
118 | size_t count, loff_t *f_pos); | |
d82b3518 MG |
119 | static int pm_qos_power_open(struct inode *inode, struct file *filp); |
120 | static int pm_qos_power_release(struct inode *inode, struct file *filp); | |
121 | ||
122 | static const struct file_operations pm_qos_power_fops = { | |
123 | .write = pm_qos_power_write, | |
f9b9e806 | 124 | .read = pm_qos_power_read, |
d82b3518 MG |
125 | .open = pm_qos_power_open, |
126 | .release = pm_qos_power_release, | |
6038f373 | 127 | .llseek = noop_llseek, |
d82b3518 MG |
128 | }; |
129 | ||
5f279845 | 130 | /* unlocked internal variant */ |
abe98ec2 | 131 | static inline int pm_qos_get_value(struct pm_qos_constraints *c) |
d82b3518 | 132 | { |
abe98ec2 | 133 | if (plist_head_empty(&c->list)) |
327adaed | 134 | return c->no_constraint_value; |
d82b3518 | 135 | |
abe98ec2 | 136 | switch (c->type) { |
5f279845 | 137 | case PM_QOS_MIN: |
abe98ec2 | 138 | return plist_first(&c->list)->prio; |
d82b3518 | 139 | |
5f279845 | 140 | case PM_QOS_MAX: |
abe98ec2 | 141 | return plist_last(&c->list)->prio; |
d82b3518 | 142 | |
5f279845 JB |
143 | default: |
144 | /* runtime check for not using enum */ | |
145 | BUG(); | |
c6a57bff | 146 | return PM_QOS_DEFAULT_VALUE; |
5f279845 JB |
147 | } |
148 | } | |
149 | ||
b66213cd | 150 | s32 pm_qos_read_value(struct pm_qos_constraints *c) |
333c5ae9 | 151 | { |
abe98ec2 | 152 | return c->target_value; |
333c5ae9 TC |
153 | } |
154 | ||
abe98ec2 | 155 | static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) |
333c5ae9 | 156 | { |
abe98ec2 | 157 | c->target_value = value; |
333c5ae9 TC |
158 | } |
159 | ||
abe98ec2 JP |
160 | /** |
161 | * pm_qos_update_target - manages the constraints list and calls the notifiers | |
162 | * if needed | |
163 | * @c: constraints data struct | |
164 | * @node: request to add to the list, to update or to remove | |
165 | * @action: action to take on the constraints list | |
166 | * @value: value of the request to add or update | |
167 | * | |
168 | * This function returns 1 if the aggregated constraint value has changed, 0 | |
169 | * otherwise. | |
170 | */ | |
171 | int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, | |
172 | enum pm_qos_req_action action, int value) | |
d82b3518 | 173 | { |
d82b3518 | 174 | unsigned long flags; |
abe98ec2 | 175 | int prev_value, curr_value, new_value; |
2d984ad1 | 176 | int ret; |
d82b3518 MG |
177 | |
178 | spin_lock_irqsave(&pm_qos_lock, flags); | |
abe98ec2 JP |
179 | prev_value = pm_qos_get_value(c); |
180 | if (value == PM_QOS_DEFAULT_VALUE) | |
181 | new_value = c->default_value; | |
182 | else | |
183 | new_value = value; | |
184 | ||
185 | switch (action) { | |
186 | case PM_QOS_REMOVE_REQ: | |
187 | plist_del(node, &c->list); | |
188 | break; | |
189 | case PM_QOS_UPDATE_REQ: | |
5f279845 JB |
190 | /* |
191 | * to change the list, we atomically remove, reinit | |
192 | * with new value and add, then see if the extremal | |
193 | * changed | |
194 | */ | |
abe98ec2 JP |
195 | plist_del(node, &c->list); |
196 | case PM_QOS_ADD_REQ: | |
197 | plist_node_init(node, new_value); | |
198 | plist_add(node, &c->list); | |
199 | break; | |
200 | default: | |
201 | /* no action */ | |
202 | ; | |
d82b3518 | 203 | } |
abe98ec2 JP |
204 | |
205 | curr_value = pm_qos_get_value(c); | |
206 | pm_qos_set_value(c, curr_value); | |
207 | ||
d82b3518 MG |
208 | spin_unlock_irqrestore(&pm_qos_lock, flags); |
209 | ||
247e9ee0 | 210 | trace_pm_qos_update_target(action, prev_value, curr_value); |
abe98ec2 | 211 | if (prev_value != curr_value) { |
2d984ad1 RW |
212 | ret = 1; |
213 | if (c->notifiers) | |
214 | blocking_notifier_call_chain(c->notifiers, | |
215 | (unsigned long)curr_value, | |
216 | NULL); | |
abe98ec2 | 217 | } else { |
2d984ad1 | 218 | ret = 0; |
abe98ec2 | 219 | } |
2d984ad1 | 220 | return ret; |
d82b3518 MG |
221 | } |
222 | ||
5efbe427 RW |
223 | /** |
224 | * pm_qos_flags_remove_req - Remove device PM QoS flags request. | |
225 | * @pqf: Device PM QoS flags set to remove the request from. | |
226 | * @req: Request to remove from the set. | |
227 | */ | |
228 | static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf, | |
229 | struct pm_qos_flags_request *req) | |
230 | { | |
231 | s32 val = 0; | |
232 | ||
233 | list_del(&req->node); | |
234 | list_for_each_entry(req, &pqf->list, node) | |
235 | val |= req->flags; | |
236 | ||
237 | pqf->effective_flags = val; | |
238 | } | |
239 | ||
240 | /** | |
241 | * pm_qos_update_flags - Update a set of PM QoS flags. | |
242 | * @pqf: Set of flags to update. | |
243 | * @req: Request to add to the set, to modify, or to remove from the set. | |
244 | * @action: Action to take on the set. | |
245 | * @val: Value of the request to add or modify. | |
246 | * | |
247 | * Update the given set of PM QoS flags and call notifiers if the aggregate | |
248 | * value has changed. Returns 1 if the aggregate constraint value has changed, | |
249 | * 0 otherwise. | |
250 | */ | |
251 | bool pm_qos_update_flags(struct pm_qos_flags *pqf, | |
252 | struct pm_qos_flags_request *req, | |
253 | enum pm_qos_req_action action, s32 val) | |
254 | { | |
255 | unsigned long irqflags; | |
256 | s32 prev_value, curr_value; | |
257 | ||
258 | spin_lock_irqsave(&pm_qos_lock, irqflags); | |
259 | ||
260 | prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; | |
261 | ||
262 | switch (action) { | |
263 | case PM_QOS_REMOVE_REQ: | |
264 | pm_qos_flags_remove_req(pqf, req); | |
265 | break; | |
266 | case PM_QOS_UPDATE_REQ: | |
267 | pm_qos_flags_remove_req(pqf, req); | |
268 | case PM_QOS_ADD_REQ: | |
269 | req->flags = val; | |
270 | INIT_LIST_HEAD(&req->node); | |
271 | list_add_tail(&req->node, &pqf->list); | |
272 | pqf->effective_flags |= val; | |
273 | break; | |
274 | default: | |
275 | /* no action */ | |
276 | ; | |
277 | } | |
278 | ||
279 | curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; | |
280 | ||
281 | spin_unlock_irqrestore(&pm_qos_lock, irqflags); | |
282 | ||
247e9ee0 | 283 | trace_pm_qos_update_flags(action, prev_value, curr_value); |
5efbe427 RW |
284 | return prev_value != curr_value; |
285 | } | |
286 | ||
d82b3518 | 287 | /** |
ed77134b | 288 | * pm_qos_request - returns current system wide qos expectation |
d82b3518 MG |
289 | * @pm_qos_class: identification of which qos value is requested |
290 | * | |
333c5ae9 | 291 | * This function returns the current target value. |
d82b3518 | 292 | */ |
ed77134b | 293 | int pm_qos_request(int pm_qos_class) |
d82b3518 | 294 | { |
abe98ec2 | 295 | return pm_qos_read_value(pm_qos_array[pm_qos_class]->constraints); |
d82b3518 | 296 | } |
ed77134b | 297 | EXPORT_SYMBOL_GPL(pm_qos_request); |
d82b3518 | 298 | |
cc749986 | 299 | int pm_qos_request_active(struct pm_qos_request *req) |
82f68251 JB |
300 | { |
301 | return req->pm_qos_class != 0; | |
302 | } | |
303 | EXPORT_SYMBOL_GPL(pm_qos_request_active); | |
304 | ||
40fea92f SB |
305 | static void __pm_qos_update_request(struct pm_qos_request *req, |
306 | s32 new_value) | |
307 | { | |
308 | trace_pm_qos_update_request(req->pm_qos_class, new_value); | |
309 | ||
310 | if (new_value != req->node.prio) | |
311 | pm_qos_update_target( | |
312 | pm_qos_array[req->pm_qos_class]->constraints, | |
313 | &req->node, PM_QOS_UPDATE_REQ, new_value); | |
314 | } | |
315 | ||
c4772d19 MH |
316 | /** |
317 | * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout | |
318 | * @work: work struct for the delayed work (timeout) | |
319 | * | |
320 | * This cancels the timeout request by falling back to the default at timeout. | |
321 | */ | |
322 | static void pm_qos_work_fn(struct work_struct *work) | |
323 | { | |
324 | struct pm_qos_request *req = container_of(to_delayed_work(work), | |
325 | struct pm_qos_request, | |
326 | work); | |
327 | ||
40fea92f | 328 | __pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE); |
c4772d19 MH |
329 | } |
330 | ||
d82b3518 | 331 | /** |
ed77134b | 332 | * pm_qos_add_request - inserts new qos request into the list |
cc749986 | 333 | * @req: pointer to a preallocated handle |
25cc69ec | 334 | * @pm_qos_class: identifies which list of qos request to use |
d82b3518 MG |
335 | * @value: defines the qos request |
336 | * | |
337 | * This function inserts a new entry in the pm_qos_class list of requested qos | |
bf1db69f | 338 | * performance characteristics. It recomputes the aggregate QoS expectations |
cc749986 | 339 | * for the pm_qos_class of parameters and initializes the pm_qos_request |
25cc69ec SK |
340 | * handle. Caller needs to save this handle for later use in updates and |
341 | * removal. | |
d82b3518 | 342 | */ |
25cc69ec | 343 | |
cc749986 | 344 | void pm_qos_add_request(struct pm_qos_request *req, |
82f68251 | 345 | int pm_qos_class, s32 value) |
d82b3518 | 346 | { |
abe98ec2 JP |
347 | if (!req) /*guard against callers passing in null */ |
348 | return; | |
d82b3518 | 349 | |
cc749986 | 350 | if (pm_qos_request_active(req)) { |
82f68251 JB |
351 | WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); |
352 | return; | |
353 | } | |
cc749986 | 354 | req->pm_qos_class = pm_qos_class; |
c4772d19 | 355 | INIT_DELAYED_WORK(&req->work, pm_qos_work_fn); |
ae8822b8 | 356 | trace_pm_qos_add_request(pm_qos_class, value); |
abe98ec2 JP |
357 | pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, |
358 | &req->node, PM_QOS_ADD_REQ, value); | |
d82b3518 | 359 | } |
ed77134b | 360 | EXPORT_SYMBOL_GPL(pm_qos_add_request); |
d82b3518 MG |
361 | |
362 | /** | |
ed77134b | 363 | * pm_qos_update_request - modifies an existing qos request |
cc749986 | 364 | * @req : handle to list element holding a pm_qos request to use |
d82b3518 MG |
365 | * @value: defines the qos request |
366 | * | |
ed77134b | 367 | * Updates an existing qos request for the pm_qos_class of parameters along |
d82b3518 MG |
368 | * with updating the target pm_qos_class value. |
369 | * | |
ed77134b | 370 | * Attempts are made to make this code callable on hot code paths. |
d82b3518 | 371 | */ |
cc749986 | 372 | void pm_qos_update_request(struct pm_qos_request *req, |
5f279845 | 373 | s32 new_value) |
d82b3518 | 374 | { |
cc749986 | 375 | if (!req) /*guard against callers passing in null */ |
5f279845 JB |
376 | return; |
377 | ||
cc749986 | 378 | if (!pm_qos_request_active(req)) { |
82f68251 JB |
379 | WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n"); |
380 | return; | |
381 | } | |
382 | ||
ed1ac6e9 | 383 | cancel_delayed_work_sync(&req->work); |
40fea92f | 384 | __pm_qos_update_request(req, new_value); |
d82b3518 | 385 | } |
ed77134b | 386 | EXPORT_SYMBOL_GPL(pm_qos_update_request); |
d82b3518 | 387 | |
c4772d19 MH |
388 | /** |
389 | * pm_qos_update_request_timeout - modifies an existing qos request temporarily. | |
390 | * @req : handle to list element holding a pm_qos request to use | |
391 | * @new_value: defines the temporal qos request | |
392 | * @timeout_us: the effective duration of this qos request in usecs. | |
393 | * | |
394 | * After timeout_us, this qos request is cancelled automatically. | |
395 | */ | |
396 | void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, | |
397 | unsigned long timeout_us) | |
398 | { | |
399 | if (!req) | |
400 | return; | |
401 | if (WARN(!pm_qos_request_active(req), | |
402 | "%s called for unknown object.", __func__)) | |
403 | return; | |
404 | ||
ed1ac6e9 | 405 | cancel_delayed_work_sync(&req->work); |
c4772d19 | 406 | |
ae8822b8 S |
407 | trace_pm_qos_update_request_timeout(req->pm_qos_class, |
408 | new_value, timeout_us); | |
c4772d19 MH |
409 | if (new_value != req->node.prio) |
410 | pm_qos_update_target( | |
411 | pm_qos_array[req->pm_qos_class]->constraints, | |
412 | &req->node, PM_QOS_UPDATE_REQ, new_value); | |
413 | ||
414 | schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us)); | |
415 | } | |
416 | ||
d82b3518 | 417 | /** |
ed77134b | 418 | * pm_qos_remove_request - modifies an existing qos request |
cc749986 | 419 | * @req: handle to request list element |
d82b3518 | 420 | * |
cc749986 | 421 | * Will remove pm qos request from the list of constraints and |
ed77134b MG |
422 | * recompute the current target value for the pm_qos_class. Call this |
423 | * on slow code paths. | |
d82b3518 | 424 | */ |
cc749986 | 425 | void pm_qos_remove_request(struct pm_qos_request *req) |
d82b3518 | 426 | { |
abe98ec2 | 427 | if (!req) /*guard against callers passing in null */ |
ed77134b MG |
428 | return; |
429 | /* silent return to keep pcm code cleaner */ | |
d82b3518 | 430 | |
cc749986 | 431 | if (!pm_qos_request_active(req)) { |
82f68251 JB |
432 | WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n"); |
433 | return; | |
434 | } | |
435 | ||
ed1ac6e9 | 436 | cancel_delayed_work_sync(&req->work); |
c4772d19 | 437 | |
ae8822b8 | 438 | trace_pm_qos_remove_request(req->pm_qos_class, PM_QOS_DEFAULT_VALUE); |
abe98ec2 JP |
439 | pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, |
440 | &req->node, PM_QOS_REMOVE_REQ, | |
441 | PM_QOS_DEFAULT_VALUE); | |
cc749986 | 442 | memset(req, 0, sizeof(*req)); |
d82b3518 | 443 | } |
ed77134b | 444 | EXPORT_SYMBOL_GPL(pm_qos_remove_request); |
d82b3518 MG |
445 | |
446 | /** | |
447 | * pm_qos_add_notifier - sets notification entry for changes to target value | |
448 | * @pm_qos_class: identifies which qos target changes should be notified. | |
449 | * @notifier: notifier block managed by caller. | |
450 | * | |
451 | * will register the notifier into a notification chain that gets called | |
bf1db69f | 452 | * upon changes to the pm_qos_class target value. |
d82b3518 | 453 | */ |
ed77134b | 454 | int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) |
d82b3518 MG |
455 | { |
456 | int retval; | |
457 | ||
458 | retval = blocking_notifier_chain_register( | |
4e1779ba JP |
459 | pm_qos_array[pm_qos_class]->constraints->notifiers, |
460 | notifier); | |
d82b3518 MG |
461 | |
462 | return retval; | |
463 | } | |
464 | EXPORT_SYMBOL_GPL(pm_qos_add_notifier); | |
465 | ||
466 | /** | |
467 | * pm_qos_remove_notifier - deletes notification entry from chain. | |
468 | * @pm_qos_class: identifies which qos target changes are notified. | |
469 | * @notifier: notifier block to be removed. | |
470 | * | |
471 | * will remove the notifier from the notification chain that gets called | |
bf1db69f | 472 | * upon changes to the pm_qos_class target value. |
d82b3518 MG |
473 | */ |
474 | int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) | |
475 | { | |
476 | int retval; | |
477 | ||
478 | retval = blocking_notifier_chain_unregister( | |
4e1779ba JP |
479 | pm_qos_array[pm_qos_class]->constraints->notifiers, |
480 | notifier); | |
d82b3518 MG |
481 | |
482 | return retval; | |
483 | } | |
484 | EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); | |
485 | ||
4a31a334 JP |
486 | /* User space interface to PM QoS classes via misc devices */ |
487 | static int register_pm_qos_misc(struct pm_qos_object *qos) | |
488 | { | |
489 | qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR; | |
490 | qos->pm_qos_power_miscdev.name = qos->name; | |
491 | qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops; | |
492 | ||
493 | return misc_register(&qos->pm_qos_power_miscdev); | |
494 | } | |
495 | ||
496 | static int find_pm_qos_object_by_minor(int minor) | |
497 | { | |
498 | int pm_qos_class; | |
499 | ||
d24c2a4f | 500 | for (pm_qos_class = PM_QOS_CPU_DMA_LATENCY; |
4a31a334 JP |
501 | pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) { |
502 | if (minor == | |
503 | pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor) | |
504 | return pm_qos_class; | |
505 | } | |
506 | return -1; | |
507 | } | |
508 | ||
d82b3518 MG |
509 | static int pm_qos_power_open(struct inode *inode, struct file *filp) |
510 | { | |
d82b3518 MG |
511 | long pm_qos_class; |
512 | ||
513 | pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); | |
d24c2a4f | 514 | if (pm_qos_class >= PM_QOS_CPU_DMA_LATENCY) { |
cc749986 | 515 | struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL); |
82f68251 JB |
516 | if (!req) |
517 | return -ENOMEM; | |
518 | ||
519 | pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE); | |
520 | filp->private_data = req; | |
ed77134b | 521 | |
6513fd69 | 522 | return 0; |
d82b3518 | 523 | } |
d82b3518 MG |
524 | return -EPERM; |
525 | } | |
526 | ||
527 | static int pm_qos_power_release(struct inode *inode, struct file *filp) | |
528 | { | |
cc749986 | 529 | struct pm_qos_request *req; |
d82b3518 | 530 | |
82f68251 | 531 | req = filp->private_data; |
ed77134b | 532 | pm_qos_remove_request(req); |
82f68251 | 533 | kfree(req); |
d82b3518 MG |
534 | |
535 | return 0; | |
536 | } | |
537 | ||
ed77134b | 538 | |
f9b9e806 TR |
539 | static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, |
540 | size_t count, loff_t *f_pos) | |
541 | { | |
542 | s32 value; | |
543 | unsigned long flags; | |
cc749986 | 544 | struct pm_qos_request *req = filp->private_data; |
f9b9e806 | 545 | |
cc749986 | 546 | if (!req) |
f9b9e806 | 547 | return -EINVAL; |
cc749986 | 548 | if (!pm_qos_request_active(req)) |
f9b9e806 TR |
549 | return -EINVAL; |
550 | ||
f9b9e806 | 551 | spin_lock_irqsave(&pm_qos_lock, flags); |
abe98ec2 | 552 | value = pm_qos_get_value(pm_qos_array[req->pm_qos_class]->constraints); |
f9b9e806 TR |
553 | spin_unlock_irqrestore(&pm_qos_lock, flags); |
554 | ||
555 | return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32)); | |
556 | } | |
557 | ||
d82b3518 MG |
558 | static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, |
559 | size_t count, loff_t *f_pos) | |
560 | { | |
561 | s32 value; | |
cc749986 | 562 | struct pm_qos_request *req; |
ed77134b MG |
563 | |
564 | if (count == sizeof(s32)) { | |
565 | if (copy_from_user(&value, buf, sizeof(s32))) | |
566 | return -EFAULT; | |
d4f7ecf7 | 567 | } else { |
0775a60a RW |
568 | int ret; |
569 | ||
d4f7ecf7 AS |
570 | ret = kstrtos32_from_user(buf, count, 16, &value); |
571 | if (ret) | |
572 | return ret; | |
0775a60a | 573 | } |
d82b3518 | 574 | |
cc749986 JP |
575 | req = filp->private_data; |
576 | pm_qos_update_request(req, value); | |
ed77134b MG |
577 | |
578 | return count; | |
d82b3518 MG |
579 | } |
580 | ||
581 | ||
582 | static int __init pm_qos_power_init(void) | |
583 | { | |
584 | int ret = 0; | |
d031e1de | 585 | int i; |
d82b3518 | 586 | |
d031e1de AF |
587 | BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES); |
588 | ||
d24c2a4f | 589 | for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) { |
d031e1de AF |
590 | ret = register_pm_qos_misc(pm_qos_array[i]); |
591 | if (ret < 0) { | |
592 | printk(KERN_ERR "pm_qos_param: %s setup failed\n", | |
593 | pm_qos_array[i]->name); | |
594 | return ret; | |
595 | } | |
d82b3518 | 596 | } |
d82b3518 MG |
597 | |
598 | return ret; | |
599 | } | |
600 | ||
601 | late_initcall(pm_qos_power_init); |