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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 | ||
7990da71 TV |
108 | static BLOCKING_NOTIFIER_HEAD(memory_bandwidth_notifier); |
109 | static struct pm_qos_constraints memory_bw_constraints = { | |
110 | .list = PLIST_HEAD_INIT(memory_bw_constraints.list), | |
111 | .target_value = PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE, | |
112 | .default_value = PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE, | |
113 | .no_constraint_value = PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE, | |
114 | .type = PM_QOS_SUM, | |
115 | .notifiers = &memory_bandwidth_notifier, | |
116 | }; | |
117 | static struct pm_qos_object memory_bandwidth_pm_qos = { | |
118 | .constraints = &memory_bw_constraints, | |
119 | .name = "memory_bandwidth", | |
120 | }; | |
121 | ||
122 | ||
d82b3518 MG |
123 | static struct pm_qos_object *pm_qos_array[] = { |
124 | &null_pm_qos, | |
125 | &cpu_dma_pm_qos, | |
126 | &network_lat_pm_qos, | |
7990da71 TV |
127 | &network_throughput_pm_qos, |
128 | &memory_bandwidth_pm_qos, | |
d82b3518 MG |
129 | }; |
130 | ||
d82b3518 MG |
131 | static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, |
132 | size_t count, loff_t *f_pos); | |
f9b9e806 TR |
133 | static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, |
134 | size_t count, loff_t *f_pos); | |
d82b3518 MG |
135 | static int pm_qos_power_open(struct inode *inode, struct file *filp); |
136 | static int pm_qos_power_release(struct inode *inode, struct file *filp); | |
137 | ||
138 | static const struct file_operations pm_qos_power_fops = { | |
139 | .write = pm_qos_power_write, | |
f9b9e806 | 140 | .read = pm_qos_power_read, |
d82b3518 MG |
141 | .open = pm_qos_power_open, |
142 | .release = pm_qos_power_release, | |
6038f373 | 143 | .llseek = noop_llseek, |
d82b3518 MG |
144 | }; |
145 | ||
5f279845 | 146 | /* unlocked internal variant */ |
abe98ec2 | 147 | static inline int pm_qos_get_value(struct pm_qos_constraints *c) |
d82b3518 | 148 | { |
7990da71 TV |
149 | struct plist_node *node; |
150 | int total_value = 0; | |
151 | ||
abe98ec2 | 152 | if (plist_head_empty(&c->list)) |
327adaed | 153 | return c->no_constraint_value; |
d82b3518 | 154 | |
abe98ec2 | 155 | switch (c->type) { |
5f279845 | 156 | case PM_QOS_MIN: |
abe98ec2 | 157 | return plist_first(&c->list)->prio; |
d82b3518 | 158 | |
5f279845 | 159 | case PM_QOS_MAX: |
abe98ec2 | 160 | return plist_last(&c->list)->prio; |
d82b3518 | 161 | |
7990da71 TV |
162 | case PM_QOS_SUM: |
163 | plist_for_each(node, &c->list) | |
164 | total_value += node->prio; | |
165 | ||
166 | return total_value; | |
167 | ||
5f279845 JB |
168 | default: |
169 | /* runtime check for not using enum */ | |
170 | BUG(); | |
c6a57bff | 171 | return PM_QOS_DEFAULT_VALUE; |
5f279845 JB |
172 | } |
173 | } | |
174 | ||
b66213cd | 175 | s32 pm_qos_read_value(struct pm_qos_constraints *c) |
333c5ae9 | 176 | { |
abe98ec2 | 177 | return c->target_value; |
333c5ae9 TC |
178 | } |
179 | ||
abe98ec2 | 180 | static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) |
333c5ae9 | 181 | { |
abe98ec2 | 182 | c->target_value = value; |
333c5ae9 TC |
183 | } |
184 | ||
abe98ec2 JP |
185 | /** |
186 | * pm_qos_update_target - manages the constraints list and calls the notifiers | |
187 | * if needed | |
188 | * @c: constraints data struct | |
189 | * @node: request to add to the list, to update or to remove | |
190 | * @action: action to take on the constraints list | |
191 | * @value: value of the request to add or update | |
192 | * | |
193 | * This function returns 1 if the aggregated constraint value has changed, 0 | |
194 | * otherwise. | |
195 | */ | |
196 | int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, | |
197 | enum pm_qos_req_action action, int value) | |
d82b3518 | 198 | { |
d82b3518 | 199 | unsigned long flags; |
abe98ec2 | 200 | int prev_value, curr_value, new_value; |
2d984ad1 | 201 | int ret; |
d82b3518 MG |
202 | |
203 | spin_lock_irqsave(&pm_qos_lock, flags); | |
abe98ec2 JP |
204 | prev_value = pm_qos_get_value(c); |
205 | if (value == PM_QOS_DEFAULT_VALUE) | |
206 | new_value = c->default_value; | |
207 | else | |
208 | new_value = value; | |
209 | ||
210 | switch (action) { | |
211 | case PM_QOS_REMOVE_REQ: | |
212 | plist_del(node, &c->list); | |
213 | break; | |
214 | case PM_QOS_UPDATE_REQ: | |
5f279845 JB |
215 | /* |
216 | * to change the list, we atomically remove, reinit | |
217 | * with new value and add, then see if the extremal | |
218 | * changed | |
219 | */ | |
abe98ec2 JP |
220 | plist_del(node, &c->list); |
221 | case PM_QOS_ADD_REQ: | |
222 | plist_node_init(node, new_value); | |
223 | plist_add(node, &c->list); | |
224 | break; | |
225 | default: | |
226 | /* no action */ | |
227 | ; | |
d82b3518 | 228 | } |
abe98ec2 JP |
229 | |
230 | curr_value = pm_qos_get_value(c); | |
231 | pm_qos_set_value(c, curr_value); | |
232 | ||
d82b3518 MG |
233 | spin_unlock_irqrestore(&pm_qos_lock, flags); |
234 | ||
247e9ee0 | 235 | trace_pm_qos_update_target(action, prev_value, curr_value); |
abe98ec2 | 236 | if (prev_value != curr_value) { |
2d984ad1 RW |
237 | ret = 1; |
238 | if (c->notifiers) | |
239 | blocking_notifier_call_chain(c->notifiers, | |
240 | (unsigned long)curr_value, | |
241 | NULL); | |
abe98ec2 | 242 | } else { |
2d984ad1 | 243 | ret = 0; |
abe98ec2 | 244 | } |
2d984ad1 | 245 | return ret; |
d82b3518 MG |
246 | } |
247 | ||
5efbe427 RW |
248 | /** |
249 | * pm_qos_flags_remove_req - Remove device PM QoS flags request. | |
250 | * @pqf: Device PM QoS flags set to remove the request from. | |
251 | * @req: Request to remove from the set. | |
252 | */ | |
253 | static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf, | |
254 | struct pm_qos_flags_request *req) | |
255 | { | |
256 | s32 val = 0; | |
257 | ||
258 | list_del(&req->node); | |
259 | list_for_each_entry(req, &pqf->list, node) | |
260 | val |= req->flags; | |
261 | ||
262 | pqf->effective_flags = val; | |
263 | } | |
264 | ||
265 | /** | |
266 | * pm_qos_update_flags - Update a set of PM QoS flags. | |
267 | * @pqf: Set of flags to update. | |
268 | * @req: Request to add to the set, to modify, or to remove from the set. | |
269 | * @action: Action to take on the set. | |
270 | * @val: Value of the request to add or modify. | |
271 | * | |
272 | * Update the given set of PM QoS flags and call notifiers if the aggregate | |
273 | * value has changed. Returns 1 if the aggregate constraint value has changed, | |
274 | * 0 otherwise. | |
275 | */ | |
276 | bool pm_qos_update_flags(struct pm_qos_flags *pqf, | |
277 | struct pm_qos_flags_request *req, | |
278 | enum pm_qos_req_action action, s32 val) | |
279 | { | |
280 | unsigned long irqflags; | |
281 | s32 prev_value, curr_value; | |
282 | ||
283 | spin_lock_irqsave(&pm_qos_lock, irqflags); | |
284 | ||
285 | prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; | |
286 | ||
287 | switch (action) { | |
288 | case PM_QOS_REMOVE_REQ: | |
289 | pm_qos_flags_remove_req(pqf, req); | |
290 | break; | |
291 | case PM_QOS_UPDATE_REQ: | |
292 | pm_qos_flags_remove_req(pqf, req); | |
293 | case PM_QOS_ADD_REQ: | |
294 | req->flags = val; | |
295 | INIT_LIST_HEAD(&req->node); | |
296 | list_add_tail(&req->node, &pqf->list); | |
297 | pqf->effective_flags |= val; | |
298 | break; | |
299 | default: | |
300 | /* no action */ | |
301 | ; | |
302 | } | |
303 | ||
304 | curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; | |
305 | ||
306 | spin_unlock_irqrestore(&pm_qos_lock, irqflags); | |
307 | ||
247e9ee0 | 308 | trace_pm_qos_update_flags(action, prev_value, curr_value); |
5efbe427 RW |
309 | return prev_value != curr_value; |
310 | } | |
311 | ||
d82b3518 | 312 | /** |
ed77134b | 313 | * pm_qos_request - returns current system wide qos expectation |
d82b3518 MG |
314 | * @pm_qos_class: identification of which qos value is requested |
315 | * | |
333c5ae9 | 316 | * This function returns the current target value. |
d82b3518 | 317 | */ |
ed77134b | 318 | int pm_qos_request(int pm_qos_class) |
d82b3518 | 319 | { |
abe98ec2 | 320 | return pm_qos_read_value(pm_qos_array[pm_qos_class]->constraints); |
d82b3518 | 321 | } |
ed77134b | 322 | EXPORT_SYMBOL_GPL(pm_qos_request); |
d82b3518 | 323 | |
cc749986 | 324 | int pm_qos_request_active(struct pm_qos_request *req) |
82f68251 JB |
325 | { |
326 | return req->pm_qos_class != 0; | |
327 | } | |
328 | EXPORT_SYMBOL_GPL(pm_qos_request_active); | |
329 | ||
40fea92f SB |
330 | static void __pm_qos_update_request(struct pm_qos_request *req, |
331 | s32 new_value) | |
332 | { | |
333 | trace_pm_qos_update_request(req->pm_qos_class, new_value); | |
334 | ||
335 | if (new_value != req->node.prio) | |
336 | pm_qos_update_target( | |
337 | pm_qos_array[req->pm_qos_class]->constraints, | |
338 | &req->node, PM_QOS_UPDATE_REQ, new_value); | |
339 | } | |
340 | ||
c4772d19 MH |
341 | /** |
342 | * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout | |
343 | * @work: work struct for the delayed work (timeout) | |
344 | * | |
345 | * This cancels the timeout request by falling back to the default at timeout. | |
346 | */ | |
347 | static void pm_qos_work_fn(struct work_struct *work) | |
348 | { | |
349 | struct pm_qos_request *req = container_of(to_delayed_work(work), | |
350 | struct pm_qos_request, | |
351 | work); | |
352 | ||
40fea92f | 353 | __pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE); |
c4772d19 MH |
354 | } |
355 | ||
d82b3518 | 356 | /** |
ed77134b | 357 | * pm_qos_add_request - inserts new qos request into the list |
cc749986 | 358 | * @req: pointer to a preallocated handle |
25cc69ec | 359 | * @pm_qos_class: identifies which list of qos request to use |
d82b3518 MG |
360 | * @value: defines the qos request |
361 | * | |
362 | * This function inserts a new entry in the pm_qos_class list of requested qos | |
bf1db69f | 363 | * performance characteristics. It recomputes the aggregate QoS expectations |
cc749986 | 364 | * for the pm_qos_class of parameters and initializes the pm_qos_request |
25cc69ec SK |
365 | * handle. Caller needs to save this handle for later use in updates and |
366 | * removal. | |
d82b3518 | 367 | */ |
25cc69ec | 368 | |
cc749986 | 369 | void pm_qos_add_request(struct pm_qos_request *req, |
82f68251 | 370 | int pm_qos_class, s32 value) |
d82b3518 | 371 | { |
abe98ec2 JP |
372 | if (!req) /*guard against callers passing in null */ |
373 | return; | |
d82b3518 | 374 | |
cc749986 | 375 | if (pm_qos_request_active(req)) { |
82f68251 JB |
376 | WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); |
377 | return; | |
378 | } | |
cc749986 | 379 | req->pm_qos_class = pm_qos_class; |
c4772d19 | 380 | INIT_DELAYED_WORK(&req->work, pm_qos_work_fn); |
ae8822b8 | 381 | trace_pm_qos_add_request(pm_qos_class, value); |
abe98ec2 JP |
382 | pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, |
383 | &req->node, PM_QOS_ADD_REQ, value); | |
d82b3518 | 384 | } |
ed77134b | 385 | EXPORT_SYMBOL_GPL(pm_qos_add_request); |
d82b3518 MG |
386 | |
387 | /** | |
ed77134b | 388 | * pm_qos_update_request - modifies an existing qos request |
cc749986 | 389 | * @req : handle to list element holding a pm_qos request to use |
d82b3518 MG |
390 | * @value: defines the qos request |
391 | * | |
ed77134b | 392 | * Updates an existing qos request for the pm_qos_class of parameters along |
d82b3518 MG |
393 | * with updating the target pm_qos_class value. |
394 | * | |
ed77134b | 395 | * Attempts are made to make this code callable on hot code paths. |
d82b3518 | 396 | */ |
cc749986 | 397 | void pm_qos_update_request(struct pm_qos_request *req, |
5f279845 | 398 | s32 new_value) |
d82b3518 | 399 | { |
cc749986 | 400 | if (!req) /*guard against callers passing in null */ |
5f279845 JB |
401 | return; |
402 | ||
cc749986 | 403 | if (!pm_qos_request_active(req)) { |
82f68251 JB |
404 | WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n"); |
405 | return; | |
406 | } | |
407 | ||
ed1ac6e9 | 408 | cancel_delayed_work_sync(&req->work); |
40fea92f | 409 | __pm_qos_update_request(req, new_value); |
d82b3518 | 410 | } |
ed77134b | 411 | EXPORT_SYMBOL_GPL(pm_qos_update_request); |
d82b3518 | 412 | |
c4772d19 MH |
413 | /** |
414 | * pm_qos_update_request_timeout - modifies an existing qos request temporarily. | |
415 | * @req : handle to list element holding a pm_qos request to use | |
416 | * @new_value: defines the temporal qos request | |
417 | * @timeout_us: the effective duration of this qos request in usecs. | |
418 | * | |
419 | * After timeout_us, this qos request is cancelled automatically. | |
420 | */ | |
421 | void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, | |
422 | unsigned long timeout_us) | |
423 | { | |
424 | if (!req) | |
425 | return; | |
426 | if (WARN(!pm_qos_request_active(req), | |
427 | "%s called for unknown object.", __func__)) | |
428 | return; | |
429 | ||
ed1ac6e9 | 430 | cancel_delayed_work_sync(&req->work); |
c4772d19 | 431 | |
ae8822b8 S |
432 | trace_pm_qos_update_request_timeout(req->pm_qos_class, |
433 | new_value, timeout_us); | |
c4772d19 MH |
434 | if (new_value != req->node.prio) |
435 | pm_qos_update_target( | |
436 | pm_qos_array[req->pm_qos_class]->constraints, | |
437 | &req->node, PM_QOS_UPDATE_REQ, new_value); | |
438 | ||
439 | schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us)); | |
440 | } | |
441 | ||
d82b3518 | 442 | /** |
ed77134b | 443 | * pm_qos_remove_request - modifies an existing qos request |
cc749986 | 444 | * @req: handle to request list element |
d82b3518 | 445 | * |
cc749986 | 446 | * Will remove pm qos request from the list of constraints and |
ed77134b MG |
447 | * recompute the current target value for the pm_qos_class. Call this |
448 | * on slow code paths. | |
d82b3518 | 449 | */ |
cc749986 | 450 | void pm_qos_remove_request(struct pm_qos_request *req) |
d82b3518 | 451 | { |
abe98ec2 | 452 | if (!req) /*guard against callers passing in null */ |
ed77134b MG |
453 | return; |
454 | /* silent return to keep pcm code cleaner */ | |
d82b3518 | 455 | |
cc749986 | 456 | if (!pm_qos_request_active(req)) { |
82f68251 JB |
457 | WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n"); |
458 | return; | |
459 | } | |
460 | ||
ed1ac6e9 | 461 | cancel_delayed_work_sync(&req->work); |
c4772d19 | 462 | |
ae8822b8 | 463 | trace_pm_qos_remove_request(req->pm_qos_class, PM_QOS_DEFAULT_VALUE); |
abe98ec2 JP |
464 | pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, |
465 | &req->node, PM_QOS_REMOVE_REQ, | |
466 | PM_QOS_DEFAULT_VALUE); | |
cc749986 | 467 | memset(req, 0, sizeof(*req)); |
d82b3518 | 468 | } |
ed77134b | 469 | EXPORT_SYMBOL_GPL(pm_qos_remove_request); |
d82b3518 MG |
470 | |
471 | /** | |
472 | * pm_qos_add_notifier - sets notification entry for changes to target value | |
473 | * @pm_qos_class: identifies which qos target changes should be notified. | |
474 | * @notifier: notifier block managed by caller. | |
475 | * | |
476 | * will register the notifier into a notification chain that gets called | |
bf1db69f | 477 | * upon changes to the pm_qos_class target value. |
d82b3518 | 478 | */ |
ed77134b | 479 | int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) |
d82b3518 MG |
480 | { |
481 | int retval; | |
482 | ||
483 | retval = blocking_notifier_chain_register( | |
4e1779ba JP |
484 | pm_qos_array[pm_qos_class]->constraints->notifiers, |
485 | notifier); | |
d82b3518 MG |
486 | |
487 | return retval; | |
488 | } | |
489 | EXPORT_SYMBOL_GPL(pm_qos_add_notifier); | |
490 | ||
491 | /** | |
492 | * pm_qos_remove_notifier - deletes notification entry from chain. | |
493 | * @pm_qos_class: identifies which qos target changes are notified. | |
494 | * @notifier: notifier block to be removed. | |
495 | * | |
496 | * will remove the notifier from the notification chain that gets called | |
bf1db69f | 497 | * upon changes to the pm_qos_class target value. |
d82b3518 MG |
498 | */ |
499 | int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) | |
500 | { | |
501 | int retval; | |
502 | ||
503 | retval = blocking_notifier_chain_unregister( | |
4e1779ba JP |
504 | pm_qos_array[pm_qos_class]->constraints->notifiers, |
505 | notifier); | |
d82b3518 MG |
506 | |
507 | return retval; | |
508 | } | |
509 | EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); | |
510 | ||
4a31a334 JP |
511 | /* User space interface to PM QoS classes via misc devices */ |
512 | static int register_pm_qos_misc(struct pm_qos_object *qos) | |
513 | { | |
514 | qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR; | |
515 | qos->pm_qos_power_miscdev.name = qos->name; | |
516 | qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops; | |
517 | ||
518 | return misc_register(&qos->pm_qos_power_miscdev); | |
519 | } | |
520 | ||
521 | static int find_pm_qos_object_by_minor(int minor) | |
522 | { | |
523 | int pm_qos_class; | |
524 | ||
d24c2a4f | 525 | for (pm_qos_class = PM_QOS_CPU_DMA_LATENCY; |
4a31a334 JP |
526 | pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) { |
527 | if (minor == | |
528 | pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor) | |
529 | return pm_qos_class; | |
530 | } | |
531 | return -1; | |
532 | } | |
533 | ||
d82b3518 MG |
534 | static int pm_qos_power_open(struct inode *inode, struct file *filp) |
535 | { | |
d82b3518 MG |
536 | long pm_qos_class; |
537 | ||
538 | pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); | |
d24c2a4f | 539 | if (pm_qos_class >= PM_QOS_CPU_DMA_LATENCY) { |
cc749986 | 540 | struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL); |
82f68251 JB |
541 | if (!req) |
542 | return -ENOMEM; | |
543 | ||
544 | pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE); | |
545 | filp->private_data = req; | |
ed77134b | 546 | |
6513fd69 | 547 | return 0; |
d82b3518 | 548 | } |
d82b3518 MG |
549 | return -EPERM; |
550 | } | |
551 | ||
552 | static int pm_qos_power_release(struct inode *inode, struct file *filp) | |
553 | { | |
cc749986 | 554 | struct pm_qos_request *req; |
d82b3518 | 555 | |
82f68251 | 556 | req = filp->private_data; |
ed77134b | 557 | pm_qos_remove_request(req); |
82f68251 | 558 | kfree(req); |
d82b3518 MG |
559 | |
560 | return 0; | |
561 | } | |
562 | ||
ed77134b | 563 | |
f9b9e806 TR |
564 | static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, |
565 | size_t count, loff_t *f_pos) | |
566 | { | |
567 | s32 value; | |
568 | unsigned long flags; | |
cc749986 | 569 | struct pm_qos_request *req = filp->private_data; |
f9b9e806 | 570 | |
cc749986 | 571 | if (!req) |
f9b9e806 | 572 | return -EINVAL; |
cc749986 | 573 | if (!pm_qos_request_active(req)) |
f9b9e806 TR |
574 | return -EINVAL; |
575 | ||
f9b9e806 | 576 | spin_lock_irqsave(&pm_qos_lock, flags); |
abe98ec2 | 577 | value = pm_qos_get_value(pm_qos_array[req->pm_qos_class]->constraints); |
f9b9e806 TR |
578 | spin_unlock_irqrestore(&pm_qos_lock, flags); |
579 | ||
580 | return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32)); | |
581 | } | |
582 | ||
d82b3518 MG |
583 | static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, |
584 | size_t count, loff_t *f_pos) | |
585 | { | |
586 | s32 value; | |
cc749986 | 587 | struct pm_qos_request *req; |
ed77134b MG |
588 | |
589 | if (count == sizeof(s32)) { | |
590 | if (copy_from_user(&value, buf, sizeof(s32))) | |
591 | return -EFAULT; | |
d4f7ecf7 | 592 | } else { |
0775a60a RW |
593 | int ret; |
594 | ||
d4f7ecf7 AS |
595 | ret = kstrtos32_from_user(buf, count, 16, &value); |
596 | if (ret) | |
597 | return ret; | |
0775a60a | 598 | } |
d82b3518 | 599 | |
cc749986 JP |
600 | req = filp->private_data; |
601 | pm_qos_update_request(req, value); | |
ed77134b MG |
602 | |
603 | return count; | |
d82b3518 MG |
604 | } |
605 | ||
606 | ||
607 | static int __init pm_qos_power_init(void) | |
608 | { | |
609 | int ret = 0; | |
d031e1de | 610 | int i; |
d82b3518 | 611 | |
d031e1de AF |
612 | BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES); |
613 | ||
d24c2a4f | 614 | for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) { |
d031e1de AF |
615 | ret = register_pm_qos_misc(pm_qos_array[i]); |
616 | if (ret < 0) { | |
617 | printk(KERN_ERR "pm_qos_param: %s setup failed\n", | |
618 | pm_qos_array[i]->name); | |
619 | return ret; | |
620 | } | |
d82b3518 | 621 | } |
d82b3518 MG |
622 | |
623 | return ret; | |
624 | } | |
625 | ||
626 | late_initcall(pm_qos_power_init); |