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> |
d82b3518 MG |
47 | |
48 | /* | |
cc749986 | 49 | * locking rule: all changes to constraints or notifiers lists |
d82b3518 MG |
50 | * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock |
51 | * held, taken with _irqsave. One lock to rule them all | |
52 | */ | |
d82b3518 | 53 | struct pm_qos_object { |
4e1779ba | 54 | struct pm_qos_constraints *constraints; |
d82b3518 MG |
55 | struct miscdevice pm_qos_power_miscdev; |
56 | char *name; | |
d82b3518 MG |
57 | }; |
58 | ||
5f279845 JB |
59 | static DEFINE_SPINLOCK(pm_qos_lock); |
60 | ||
d82b3518 | 61 | static struct pm_qos_object null_pm_qos; |
4e1779ba | 62 | |
d82b3518 | 63 | static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); |
4e1779ba JP |
64 | static struct pm_qos_constraints cpu_dma_constraints = { |
65 | .list = PLIST_HEAD_INIT(cpu_dma_constraints.list), | |
333c5ae9 TC |
66 | .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, |
67 | .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, | |
5f279845 | 68 | .type = PM_QOS_MIN, |
4e1779ba JP |
69 | .notifiers = &cpu_dma_lat_notifier, |
70 | }; | |
71 | static struct pm_qos_object cpu_dma_pm_qos = { | |
72 | .constraints = &cpu_dma_constraints, | |
a6f05b97 | 73 | .name = "cpu_dma_latency", |
d82b3518 MG |
74 | }; |
75 | ||
76 | static BLOCKING_NOTIFIER_HEAD(network_lat_notifier); | |
4e1779ba JP |
77 | static struct pm_qos_constraints network_lat_constraints = { |
78 | .list = PLIST_HEAD_INIT(network_lat_constraints.list), | |
333c5ae9 TC |
79 | .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, |
80 | .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, | |
4e1779ba JP |
81 | .type = PM_QOS_MIN, |
82 | .notifiers = &network_lat_notifier, | |
83 | }; | |
84 | static struct pm_qos_object network_lat_pm_qos = { | |
85 | .constraints = &network_lat_constraints, | |
86 | .name = "network_latency", | |
d82b3518 MG |
87 | }; |
88 | ||
89 | ||
90 | static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier); | |
4e1779ba JP |
91 | static struct pm_qos_constraints network_tput_constraints = { |
92 | .list = PLIST_HEAD_INIT(network_tput_constraints.list), | |
333c5ae9 TC |
93 | .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, |
94 | .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, | |
5f279845 | 95 | .type = PM_QOS_MAX, |
4e1779ba JP |
96 | .notifiers = &network_throughput_notifier, |
97 | }; | |
98 | static struct pm_qos_object network_throughput_pm_qos = { | |
99 | .constraints = &network_tput_constraints, | |
100 | .name = "network_throughput", | |
d82b3518 MG |
101 | }; |
102 | ||
103 | ||
104 | static struct pm_qos_object *pm_qos_array[] = { | |
105 | &null_pm_qos, | |
106 | &cpu_dma_pm_qos, | |
107 | &network_lat_pm_qos, | |
108 | &network_throughput_pm_qos | |
109 | }; | |
110 | ||
d82b3518 MG |
111 | static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, |
112 | size_t count, loff_t *f_pos); | |
f9b9e806 TR |
113 | static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, |
114 | size_t count, loff_t *f_pos); | |
d82b3518 MG |
115 | static int pm_qos_power_open(struct inode *inode, struct file *filp); |
116 | static int pm_qos_power_release(struct inode *inode, struct file *filp); | |
117 | ||
118 | static const struct file_operations pm_qos_power_fops = { | |
119 | .write = pm_qos_power_write, | |
f9b9e806 | 120 | .read = pm_qos_power_read, |
d82b3518 MG |
121 | .open = pm_qos_power_open, |
122 | .release = pm_qos_power_release, | |
6038f373 | 123 | .llseek = noop_llseek, |
d82b3518 MG |
124 | }; |
125 | ||
5f279845 | 126 | /* unlocked internal variant */ |
abe98ec2 | 127 | static inline int pm_qos_get_value(struct pm_qos_constraints *c) |
d82b3518 | 128 | { |
abe98ec2 JP |
129 | if (plist_head_empty(&c->list)) |
130 | return c->default_value; | |
d82b3518 | 131 | |
abe98ec2 | 132 | switch (c->type) { |
5f279845 | 133 | case PM_QOS_MIN: |
abe98ec2 | 134 | return plist_first(&c->list)->prio; |
d82b3518 | 135 | |
5f279845 | 136 | case PM_QOS_MAX: |
abe98ec2 | 137 | return plist_last(&c->list)->prio; |
d82b3518 | 138 | |
5f279845 JB |
139 | default: |
140 | /* runtime check for not using enum */ | |
141 | BUG(); | |
c6a57bff | 142 | return PM_QOS_DEFAULT_VALUE; |
5f279845 JB |
143 | } |
144 | } | |
145 | ||
b66213cd | 146 | s32 pm_qos_read_value(struct pm_qos_constraints *c) |
333c5ae9 | 147 | { |
abe98ec2 | 148 | return c->target_value; |
333c5ae9 TC |
149 | } |
150 | ||
abe98ec2 | 151 | static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) |
333c5ae9 | 152 | { |
abe98ec2 | 153 | c->target_value = value; |
333c5ae9 TC |
154 | } |
155 | ||
abe98ec2 JP |
156 | /** |
157 | * pm_qos_update_target - manages the constraints list and calls the notifiers | |
158 | * if needed | |
159 | * @c: constraints data struct | |
160 | * @node: request to add to the list, to update or to remove | |
161 | * @action: action to take on the constraints list | |
162 | * @value: value of the request to add or update | |
163 | * | |
164 | * This function returns 1 if the aggregated constraint value has changed, 0 | |
165 | * otherwise. | |
166 | */ | |
167 | int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, | |
168 | enum pm_qos_req_action action, int value) | |
d82b3518 | 169 | { |
d82b3518 | 170 | unsigned long flags; |
abe98ec2 | 171 | int prev_value, curr_value, new_value; |
d82b3518 MG |
172 | |
173 | spin_lock_irqsave(&pm_qos_lock, flags); | |
abe98ec2 JP |
174 | prev_value = pm_qos_get_value(c); |
175 | if (value == PM_QOS_DEFAULT_VALUE) | |
176 | new_value = c->default_value; | |
177 | else | |
178 | new_value = value; | |
179 | ||
180 | switch (action) { | |
181 | case PM_QOS_REMOVE_REQ: | |
182 | plist_del(node, &c->list); | |
183 | break; | |
184 | case PM_QOS_UPDATE_REQ: | |
5f279845 JB |
185 | /* |
186 | * to change the list, we atomically remove, reinit | |
187 | * with new value and add, then see if the extremal | |
188 | * changed | |
189 | */ | |
abe98ec2 JP |
190 | plist_del(node, &c->list); |
191 | case PM_QOS_ADD_REQ: | |
192 | plist_node_init(node, new_value); | |
193 | plist_add(node, &c->list); | |
194 | break; | |
195 | default: | |
196 | /* no action */ | |
197 | ; | |
d82b3518 | 198 | } |
abe98ec2 JP |
199 | |
200 | curr_value = pm_qos_get_value(c); | |
201 | pm_qos_set_value(c, curr_value); | |
202 | ||
d82b3518 MG |
203 | spin_unlock_irqrestore(&pm_qos_lock, flags); |
204 | ||
abe98ec2 JP |
205 | if (prev_value != curr_value) { |
206 | blocking_notifier_call_chain(c->notifiers, | |
5f279845 JB |
207 | (unsigned long)curr_value, |
208 | NULL); | |
abe98ec2 JP |
209 | return 1; |
210 | } else { | |
211 | return 0; | |
212 | } | |
d82b3518 MG |
213 | } |
214 | ||
5efbe427 RW |
215 | /** |
216 | * pm_qos_flags_remove_req - Remove device PM QoS flags request. | |
217 | * @pqf: Device PM QoS flags set to remove the request from. | |
218 | * @req: Request to remove from the set. | |
219 | */ | |
220 | static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf, | |
221 | struct pm_qos_flags_request *req) | |
222 | { | |
223 | s32 val = 0; | |
224 | ||
225 | list_del(&req->node); | |
226 | list_for_each_entry(req, &pqf->list, node) | |
227 | val |= req->flags; | |
228 | ||
229 | pqf->effective_flags = val; | |
230 | } | |
231 | ||
232 | /** | |
233 | * pm_qos_update_flags - Update a set of PM QoS flags. | |
234 | * @pqf: Set of flags to update. | |
235 | * @req: Request to add to the set, to modify, or to remove from the set. | |
236 | * @action: Action to take on the set. | |
237 | * @val: Value of the request to add or modify. | |
238 | * | |
239 | * Update the given set of PM QoS flags and call notifiers if the aggregate | |
240 | * value has changed. Returns 1 if the aggregate constraint value has changed, | |
241 | * 0 otherwise. | |
242 | */ | |
243 | bool pm_qos_update_flags(struct pm_qos_flags *pqf, | |
244 | struct pm_qos_flags_request *req, | |
245 | enum pm_qos_req_action action, s32 val) | |
246 | { | |
247 | unsigned long irqflags; | |
248 | s32 prev_value, curr_value; | |
249 | ||
250 | spin_lock_irqsave(&pm_qos_lock, irqflags); | |
251 | ||
252 | prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; | |
253 | ||
254 | switch (action) { | |
255 | case PM_QOS_REMOVE_REQ: | |
256 | pm_qos_flags_remove_req(pqf, req); | |
257 | break; | |
258 | case PM_QOS_UPDATE_REQ: | |
259 | pm_qos_flags_remove_req(pqf, req); | |
260 | case PM_QOS_ADD_REQ: | |
261 | req->flags = val; | |
262 | INIT_LIST_HEAD(&req->node); | |
263 | list_add_tail(&req->node, &pqf->list); | |
264 | pqf->effective_flags |= val; | |
265 | break; | |
266 | default: | |
267 | /* no action */ | |
268 | ; | |
269 | } | |
270 | ||
271 | curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; | |
272 | ||
273 | spin_unlock_irqrestore(&pm_qos_lock, irqflags); | |
274 | ||
275 | return prev_value != curr_value; | |
276 | } | |
277 | ||
d82b3518 | 278 | /** |
ed77134b | 279 | * pm_qos_request - returns current system wide qos expectation |
d82b3518 MG |
280 | * @pm_qos_class: identification of which qos value is requested |
281 | * | |
333c5ae9 | 282 | * This function returns the current target value. |
d82b3518 | 283 | */ |
ed77134b | 284 | int pm_qos_request(int pm_qos_class) |
d82b3518 | 285 | { |
abe98ec2 | 286 | return pm_qos_read_value(pm_qos_array[pm_qos_class]->constraints); |
d82b3518 | 287 | } |
ed77134b | 288 | EXPORT_SYMBOL_GPL(pm_qos_request); |
d82b3518 | 289 | |
cc749986 | 290 | int pm_qos_request_active(struct pm_qos_request *req) |
82f68251 JB |
291 | { |
292 | return req->pm_qos_class != 0; | |
293 | } | |
294 | EXPORT_SYMBOL_GPL(pm_qos_request_active); | |
295 | ||
c4772d19 MH |
296 | /** |
297 | * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout | |
298 | * @work: work struct for the delayed work (timeout) | |
299 | * | |
300 | * This cancels the timeout request by falling back to the default at timeout. | |
301 | */ | |
302 | static void pm_qos_work_fn(struct work_struct *work) | |
303 | { | |
304 | struct pm_qos_request *req = container_of(to_delayed_work(work), | |
305 | struct pm_qos_request, | |
306 | work); | |
307 | ||
308 | pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE); | |
309 | } | |
310 | ||
d82b3518 | 311 | /** |
ed77134b | 312 | * pm_qos_add_request - inserts new qos request into the list |
cc749986 | 313 | * @req: pointer to a preallocated handle |
25cc69ec | 314 | * @pm_qos_class: identifies which list of qos request to use |
d82b3518 MG |
315 | * @value: defines the qos request |
316 | * | |
317 | * This function inserts a new entry in the pm_qos_class list of requested qos | |
bf1db69f | 318 | * performance characteristics. It recomputes the aggregate QoS expectations |
cc749986 | 319 | * for the pm_qos_class of parameters and initializes the pm_qos_request |
25cc69ec SK |
320 | * handle. Caller needs to save this handle for later use in updates and |
321 | * removal. | |
d82b3518 | 322 | */ |
25cc69ec | 323 | |
cc749986 | 324 | void pm_qos_add_request(struct pm_qos_request *req, |
82f68251 | 325 | int pm_qos_class, s32 value) |
d82b3518 | 326 | { |
abe98ec2 JP |
327 | if (!req) /*guard against callers passing in null */ |
328 | return; | |
d82b3518 | 329 | |
cc749986 | 330 | if (pm_qos_request_active(req)) { |
82f68251 JB |
331 | WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); |
332 | return; | |
333 | } | |
cc749986 | 334 | req->pm_qos_class = pm_qos_class; |
c4772d19 | 335 | INIT_DELAYED_WORK(&req->work, pm_qos_work_fn); |
abe98ec2 JP |
336 | pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, |
337 | &req->node, PM_QOS_ADD_REQ, value); | |
d82b3518 | 338 | } |
ed77134b | 339 | EXPORT_SYMBOL_GPL(pm_qos_add_request); |
d82b3518 MG |
340 | |
341 | /** | |
ed77134b | 342 | * pm_qos_update_request - modifies an existing qos request |
cc749986 | 343 | * @req : handle to list element holding a pm_qos request to use |
d82b3518 MG |
344 | * @value: defines the qos request |
345 | * | |
ed77134b | 346 | * Updates an existing qos request for the pm_qos_class of parameters along |
d82b3518 MG |
347 | * with updating the target pm_qos_class value. |
348 | * | |
ed77134b | 349 | * Attempts are made to make this code callable on hot code paths. |
d82b3518 | 350 | */ |
cc749986 | 351 | void pm_qos_update_request(struct pm_qos_request *req, |
5f279845 | 352 | s32 new_value) |
d82b3518 | 353 | { |
cc749986 | 354 | if (!req) /*guard against callers passing in null */ |
5f279845 JB |
355 | return; |
356 | ||
cc749986 | 357 | if (!pm_qos_request_active(req)) { |
82f68251 JB |
358 | WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n"); |
359 | return; | |
360 | } | |
361 | ||
c4772d19 MH |
362 | if (delayed_work_pending(&req->work)) |
363 | cancel_delayed_work_sync(&req->work); | |
364 | ||
abe98ec2 JP |
365 | if (new_value != req->node.prio) |
366 | pm_qos_update_target( | |
367 | pm_qos_array[req->pm_qos_class]->constraints, | |
368 | &req->node, PM_QOS_UPDATE_REQ, new_value); | |
d82b3518 | 369 | } |
ed77134b | 370 | EXPORT_SYMBOL_GPL(pm_qos_update_request); |
d82b3518 | 371 | |
c4772d19 MH |
372 | /** |
373 | * pm_qos_update_request_timeout - modifies an existing qos request temporarily. | |
374 | * @req : handle to list element holding a pm_qos request to use | |
375 | * @new_value: defines the temporal qos request | |
376 | * @timeout_us: the effective duration of this qos request in usecs. | |
377 | * | |
378 | * After timeout_us, this qos request is cancelled automatically. | |
379 | */ | |
380 | void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, | |
381 | unsigned long timeout_us) | |
382 | { | |
383 | if (!req) | |
384 | return; | |
385 | if (WARN(!pm_qos_request_active(req), | |
386 | "%s called for unknown object.", __func__)) | |
387 | return; | |
388 | ||
389 | if (delayed_work_pending(&req->work)) | |
390 | cancel_delayed_work_sync(&req->work); | |
391 | ||
392 | if (new_value != req->node.prio) | |
393 | pm_qos_update_target( | |
394 | pm_qos_array[req->pm_qos_class]->constraints, | |
395 | &req->node, PM_QOS_UPDATE_REQ, new_value); | |
396 | ||
397 | schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us)); | |
398 | } | |
399 | ||
d82b3518 | 400 | /** |
ed77134b | 401 | * pm_qos_remove_request - modifies an existing qos request |
cc749986 | 402 | * @req: handle to request list element |
d82b3518 | 403 | * |
cc749986 | 404 | * Will remove pm qos request from the list of constraints and |
ed77134b MG |
405 | * recompute the current target value for the pm_qos_class. Call this |
406 | * on slow code paths. | |
d82b3518 | 407 | */ |
cc749986 | 408 | void pm_qos_remove_request(struct pm_qos_request *req) |
d82b3518 | 409 | { |
abe98ec2 | 410 | if (!req) /*guard against callers passing in null */ |
ed77134b MG |
411 | return; |
412 | /* silent return to keep pcm code cleaner */ | |
d82b3518 | 413 | |
cc749986 | 414 | if (!pm_qos_request_active(req)) { |
82f68251 JB |
415 | WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n"); |
416 | return; | |
417 | } | |
418 | ||
c4772d19 MH |
419 | if (delayed_work_pending(&req->work)) |
420 | cancel_delayed_work_sync(&req->work); | |
421 | ||
abe98ec2 JP |
422 | pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, |
423 | &req->node, PM_QOS_REMOVE_REQ, | |
424 | PM_QOS_DEFAULT_VALUE); | |
cc749986 | 425 | memset(req, 0, sizeof(*req)); |
d82b3518 | 426 | } |
ed77134b | 427 | EXPORT_SYMBOL_GPL(pm_qos_remove_request); |
d82b3518 MG |
428 | |
429 | /** | |
430 | * pm_qos_add_notifier - sets notification entry for changes to target value | |
431 | * @pm_qos_class: identifies which qos target changes should be notified. | |
432 | * @notifier: notifier block managed by caller. | |
433 | * | |
434 | * will register the notifier into a notification chain that gets called | |
bf1db69f | 435 | * upon changes to the pm_qos_class target value. |
d82b3518 | 436 | */ |
ed77134b | 437 | int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) |
d82b3518 MG |
438 | { |
439 | int retval; | |
440 | ||
441 | retval = blocking_notifier_chain_register( | |
4e1779ba JP |
442 | pm_qos_array[pm_qos_class]->constraints->notifiers, |
443 | notifier); | |
d82b3518 MG |
444 | |
445 | return retval; | |
446 | } | |
447 | EXPORT_SYMBOL_GPL(pm_qos_add_notifier); | |
448 | ||
449 | /** | |
450 | * pm_qos_remove_notifier - deletes notification entry from chain. | |
451 | * @pm_qos_class: identifies which qos target changes are notified. | |
452 | * @notifier: notifier block to be removed. | |
453 | * | |
454 | * will remove the notifier from the notification chain that gets called | |
bf1db69f | 455 | * upon changes to the pm_qos_class target value. |
d82b3518 MG |
456 | */ |
457 | int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) | |
458 | { | |
459 | int retval; | |
460 | ||
461 | retval = blocking_notifier_chain_unregister( | |
4e1779ba JP |
462 | pm_qos_array[pm_qos_class]->constraints->notifiers, |
463 | notifier); | |
d82b3518 MG |
464 | |
465 | return retval; | |
466 | } | |
467 | EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); | |
468 | ||
4a31a334 JP |
469 | /* User space interface to PM QoS classes via misc devices */ |
470 | static int register_pm_qos_misc(struct pm_qos_object *qos) | |
471 | { | |
472 | qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR; | |
473 | qos->pm_qos_power_miscdev.name = qos->name; | |
474 | qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops; | |
475 | ||
476 | return misc_register(&qos->pm_qos_power_miscdev); | |
477 | } | |
478 | ||
479 | static int find_pm_qos_object_by_minor(int minor) | |
480 | { | |
481 | int pm_qos_class; | |
482 | ||
483 | for (pm_qos_class = 0; | |
484 | pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) { | |
485 | if (minor == | |
486 | pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor) | |
487 | return pm_qos_class; | |
488 | } | |
489 | return -1; | |
490 | } | |
491 | ||
d82b3518 MG |
492 | static int pm_qos_power_open(struct inode *inode, struct file *filp) |
493 | { | |
d82b3518 MG |
494 | long pm_qos_class; |
495 | ||
496 | pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); | |
497 | if (pm_qos_class >= 0) { | |
cc749986 | 498 | struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL); |
82f68251 JB |
499 | if (!req) |
500 | return -ENOMEM; | |
501 | ||
502 | pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE); | |
503 | filp->private_data = req; | |
ed77134b | 504 | |
6513fd69 | 505 | return 0; |
d82b3518 | 506 | } |
d82b3518 MG |
507 | return -EPERM; |
508 | } | |
509 | ||
510 | static int pm_qos_power_release(struct inode *inode, struct file *filp) | |
511 | { | |
cc749986 | 512 | struct pm_qos_request *req; |
d82b3518 | 513 | |
82f68251 | 514 | req = filp->private_data; |
ed77134b | 515 | pm_qos_remove_request(req); |
82f68251 | 516 | kfree(req); |
d82b3518 MG |
517 | |
518 | return 0; | |
519 | } | |
520 | ||
ed77134b | 521 | |
f9b9e806 TR |
522 | static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, |
523 | size_t count, loff_t *f_pos) | |
524 | { | |
525 | s32 value; | |
526 | unsigned long flags; | |
cc749986 | 527 | struct pm_qos_request *req = filp->private_data; |
f9b9e806 | 528 | |
cc749986 | 529 | if (!req) |
f9b9e806 | 530 | return -EINVAL; |
cc749986 | 531 | if (!pm_qos_request_active(req)) |
f9b9e806 TR |
532 | return -EINVAL; |
533 | ||
f9b9e806 | 534 | spin_lock_irqsave(&pm_qos_lock, flags); |
abe98ec2 | 535 | value = pm_qos_get_value(pm_qos_array[req->pm_qos_class]->constraints); |
f9b9e806 TR |
536 | spin_unlock_irqrestore(&pm_qos_lock, flags); |
537 | ||
538 | return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32)); | |
539 | } | |
540 | ||
d82b3518 MG |
541 | static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, |
542 | size_t count, loff_t *f_pos) | |
543 | { | |
544 | s32 value; | |
cc749986 | 545 | struct pm_qos_request *req; |
ed77134b MG |
546 | |
547 | if (count == sizeof(s32)) { | |
548 | if (copy_from_user(&value, buf, sizeof(s32))) | |
549 | return -EFAULT; | |
0775a60a RW |
550 | } else if (count <= 11) { /* ASCII perhaps? */ |
551 | char ascii_value[11]; | |
552 | unsigned long int ulval; | |
553 | int ret; | |
554 | ||
555 | if (copy_from_user(ascii_value, buf, count)) | |
ed77134b | 556 | return -EFAULT; |
0775a60a RW |
557 | |
558 | if (count > 10) { | |
559 | if (ascii_value[10] == '\n') | |
560 | ascii_value[10] = '\0'; | |
561 | else | |
562 | return -EINVAL; | |
563 | } else { | |
564 | ascii_value[count] = '\0'; | |
565 | } | |
883ee4f7 | 566 | ret = kstrtoul(ascii_value, 16, &ulval); |
0775a60a RW |
567 | if (ret) { |
568 | pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret); | |
ed77134b | 569 | return -EINVAL; |
0775a60a RW |
570 | } |
571 | value = (s32)lower_32_bits(ulval); | |
572 | } else { | |
d82b3518 | 573 | return -EINVAL; |
0775a60a | 574 | } |
d82b3518 | 575 | |
cc749986 JP |
576 | req = filp->private_data; |
577 | pm_qos_update_request(req, value); | |
ed77134b MG |
578 | |
579 | return count; | |
d82b3518 MG |
580 | } |
581 | ||
582 | ||
583 | static int __init pm_qos_power_init(void) | |
584 | { | |
585 | int ret = 0; | |
d031e1de | 586 | int i; |
d82b3518 | 587 | |
d031e1de AF |
588 | BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES); |
589 | ||
590 | for (i = 1; i < PM_QOS_NUM_CLASSES; i++) { | |
591 | ret = register_pm_qos_misc(pm_qos_array[i]); | |
592 | if (ret < 0) { | |
593 | printk(KERN_ERR "pm_qos_param: %s setup failed\n", | |
594 | pm_qos_array[i]->name); | |
595 | return ret; | |
596 | } | |
d82b3518 | 597 | } |
d82b3518 MG |
598 | |
599 | return ret; | |
600 | } | |
601 | ||
602 | late_initcall(pm_qos_power_init); |