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> |
f5f4eda4 NM |
44 | #include <linux/debugfs.h> |
45 | #include <linux/seq_file.h> | |
d82b3518 MG |
46 | |
47 | #include <linux/uaccess.h> | |
6e5fdeed | 48 | #include <linux/export.h> |
247e9ee0 | 49 | #include <trace/events/power.h> |
d82b3518 MG |
50 | |
51 | /* | |
cc749986 | 52 | * locking rule: all changes to constraints or notifiers lists |
d82b3518 MG |
53 | * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock |
54 | * held, taken with _irqsave. One lock to rule them all | |
55 | */ | |
d82b3518 | 56 | struct pm_qos_object { |
4e1779ba | 57 | struct pm_qos_constraints *constraints; |
d82b3518 MG |
58 | struct miscdevice pm_qos_power_miscdev; |
59 | char *name; | |
d82b3518 MG |
60 | }; |
61 | ||
5f279845 JB |
62 | static DEFINE_SPINLOCK(pm_qos_lock); |
63 | ||
d82b3518 | 64 | static struct pm_qos_object null_pm_qos; |
4e1779ba | 65 | |
d82b3518 | 66 | static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); |
4e1779ba JP |
67 | static struct pm_qos_constraints cpu_dma_constraints = { |
68 | .list = PLIST_HEAD_INIT(cpu_dma_constraints.list), | |
333c5ae9 TC |
69 | .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, |
70 | .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, | |
327adaed | 71 | .no_constraint_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, |
5f279845 | 72 | .type = PM_QOS_MIN, |
4e1779ba JP |
73 | .notifiers = &cpu_dma_lat_notifier, |
74 | }; | |
75 | static struct pm_qos_object cpu_dma_pm_qos = { | |
76 | .constraints = &cpu_dma_constraints, | |
a6f05b97 | 77 | .name = "cpu_dma_latency", |
d82b3518 MG |
78 | }; |
79 | ||
80 | static BLOCKING_NOTIFIER_HEAD(network_lat_notifier); | |
4e1779ba JP |
81 | static struct pm_qos_constraints network_lat_constraints = { |
82 | .list = PLIST_HEAD_INIT(network_lat_constraints.list), | |
333c5ae9 TC |
83 | .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, |
84 | .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, | |
327adaed | 85 | .no_constraint_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, |
4e1779ba JP |
86 | .type = PM_QOS_MIN, |
87 | .notifiers = &network_lat_notifier, | |
88 | }; | |
89 | static struct pm_qos_object network_lat_pm_qos = { | |
90 | .constraints = &network_lat_constraints, | |
91 | .name = "network_latency", | |
d82b3518 MG |
92 | }; |
93 | ||
94 | ||
95 | static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier); | |
4e1779ba JP |
96 | static struct pm_qos_constraints network_tput_constraints = { |
97 | .list = PLIST_HEAD_INIT(network_tput_constraints.list), | |
333c5ae9 TC |
98 | .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, |
99 | .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, | |
327adaed | 100 | .no_constraint_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, |
5f279845 | 101 | .type = PM_QOS_MAX, |
4e1779ba JP |
102 | .notifiers = &network_throughput_notifier, |
103 | }; | |
104 | static struct pm_qos_object network_throughput_pm_qos = { | |
105 | .constraints = &network_tput_constraints, | |
106 | .name = "network_throughput", | |
d82b3518 MG |
107 | }; |
108 | ||
109 | ||
7990da71 TV |
110 | static BLOCKING_NOTIFIER_HEAD(memory_bandwidth_notifier); |
111 | static struct pm_qos_constraints memory_bw_constraints = { | |
112 | .list = PLIST_HEAD_INIT(memory_bw_constraints.list), | |
113 | .target_value = PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE, | |
114 | .default_value = PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE, | |
115 | .no_constraint_value = PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE, | |
116 | .type = PM_QOS_SUM, | |
117 | .notifiers = &memory_bandwidth_notifier, | |
118 | }; | |
119 | static struct pm_qos_object memory_bandwidth_pm_qos = { | |
120 | .constraints = &memory_bw_constraints, | |
121 | .name = "memory_bandwidth", | |
122 | }; | |
123 | ||
124 | ||
d82b3518 MG |
125 | static struct pm_qos_object *pm_qos_array[] = { |
126 | &null_pm_qos, | |
127 | &cpu_dma_pm_qos, | |
128 | &network_lat_pm_qos, | |
7990da71 TV |
129 | &network_throughput_pm_qos, |
130 | &memory_bandwidth_pm_qos, | |
d82b3518 MG |
131 | }; |
132 | ||
d82b3518 MG |
133 | static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, |
134 | size_t count, loff_t *f_pos); | |
f9b9e806 TR |
135 | static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, |
136 | size_t count, loff_t *f_pos); | |
d82b3518 MG |
137 | static int pm_qos_power_open(struct inode *inode, struct file *filp); |
138 | static int pm_qos_power_release(struct inode *inode, struct file *filp); | |
139 | ||
140 | static const struct file_operations pm_qos_power_fops = { | |
141 | .write = pm_qos_power_write, | |
f9b9e806 | 142 | .read = pm_qos_power_read, |
d82b3518 MG |
143 | .open = pm_qos_power_open, |
144 | .release = pm_qos_power_release, | |
6038f373 | 145 | .llseek = noop_llseek, |
d82b3518 MG |
146 | }; |
147 | ||
5f279845 | 148 | /* unlocked internal variant */ |
abe98ec2 | 149 | static inline int pm_qos_get_value(struct pm_qos_constraints *c) |
d82b3518 | 150 | { |
7990da71 TV |
151 | struct plist_node *node; |
152 | int total_value = 0; | |
153 | ||
abe98ec2 | 154 | if (plist_head_empty(&c->list)) |
327adaed | 155 | return c->no_constraint_value; |
d82b3518 | 156 | |
abe98ec2 | 157 | switch (c->type) { |
5f279845 | 158 | case PM_QOS_MIN: |
abe98ec2 | 159 | return plist_first(&c->list)->prio; |
d82b3518 | 160 | |
5f279845 | 161 | case PM_QOS_MAX: |
abe98ec2 | 162 | return plist_last(&c->list)->prio; |
d82b3518 | 163 | |
7990da71 TV |
164 | case PM_QOS_SUM: |
165 | plist_for_each(node, &c->list) | |
166 | total_value += node->prio; | |
167 | ||
168 | return total_value; | |
169 | ||
5f279845 JB |
170 | default: |
171 | /* runtime check for not using enum */ | |
172 | BUG(); | |
c6a57bff | 173 | return PM_QOS_DEFAULT_VALUE; |
5f279845 JB |
174 | } |
175 | } | |
176 | ||
b66213cd | 177 | s32 pm_qos_read_value(struct pm_qos_constraints *c) |
333c5ae9 | 178 | { |
abe98ec2 | 179 | return c->target_value; |
333c5ae9 TC |
180 | } |
181 | ||
abe98ec2 | 182 | static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) |
333c5ae9 | 183 | { |
abe98ec2 | 184 | c->target_value = value; |
333c5ae9 TC |
185 | } |
186 | ||
f5f4eda4 NM |
187 | static inline int pm_qos_get_value(struct pm_qos_constraints *c); |
188 | static int pm_qos_dbg_show_requests(struct seq_file *s, void *unused) | |
189 | { | |
190 | struct pm_qos_object *qos = (struct pm_qos_object *)s->private; | |
191 | struct pm_qos_constraints *c; | |
192 | struct pm_qos_request *req; | |
193 | char *type; | |
194 | unsigned long flags; | |
195 | int tot_reqs = 0; | |
196 | int active_reqs = 0; | |
197 | ||
198 | if (IS_ERR_OR_NULL(qos)) { | |
199 | pr_err("%s: bad qos param!\n", __func__); | |
200 | return -EINVAL; | |
201 | } | |
202 | c = qos->constraints; | |
203 | if (IS_ERR_OR_NULL(c)) { | |
204 | pr_err("%s: Bad constraints on qos?\n", __func__); | |
205 | return -EINVAL; | |
206 | } | |
207 | ||
208 | /* Lock to ensure we have a snapshot */ | |
209 | spin_lock_irqsave(&pm_qos_lock, flags); | |
210 | if (plist_head_empty(&c->list)) { | |
211 | seq_puts(s, "Empty!\n"); | |
212 | goto out; | |
213 | } | |
214 | ||
215 | switch (c->type) { | |
216 | case PM_QOS_MIN: | |
217 | type = "Minimum"; | |
218 | break; | |
219 | case PM_QOS_MAX: | |
220 | type = "Maximum"; | |
221 | break; | |
222 | case PM_QOS_SUM: | |
223 | type = "Sum"; | |
224 | break; | |
225 | default: | |
226 | type = "Unknown"; | |
227 | } | |
228 | ||
229 | plist_for_each_entry(req, &c->list, node) { | |
230 | char *state = "Default"; | |
231 | ||
232 | if ((req->node).prio != c->default_value) { | |
233 | active_reqs++; | |
234 | state = "Active"; | |
235 | } | |
236 | tot_reqs++; | |
237 | seq_printf(s, "%d: %d: %s\n", tot_reqs, | |
238 | (req->node).prio, state); | |
239 | } | |
240 | ||
241 | seq_printf(s, "Type=%s, Value=%d, Requests: active=%d / total=%d\n", | |
242 | type, pm_qos_get_value(c), active_reqs, tot_reqs); | |
243 | ||
244 | out: | |
245 | spin_unlock_irqrestore(&pm_qos_lock, flags); | |
246 | return 0; | |
247 | } | |
248 | ||
249 | static int pm_qos_dbg_open(struct inode *inode, struct file *file) | |
250 | { | |
251 | return single_open(file, pm_qos_dbg_show_requests, | |
252 | inode->i_private); | |
253 | } | |
254 | ||
255 | static const struct file_operations pm_qos_debug_fops = { | |
256 | .open = pm_qos_dbg_open, | |
257 | .read = seq_read, | |
258 | .llseek = seq_lseek, | |
259 | .release = single_release, | |
260 | }; | |
261 | ||
abe98ec2 JP |
262 | /** |
263 | * pm_qos_update_target - manages the constraints list and calls the notifiers | |
264 | * if needed | |
265 | * @c: constraints data struct | |
266 | * @node: request to add to the list, to update or to remove | |
267 | * @action: action to take on the constraints list | |
268 | * @value: value of the request to add or update | |
269 | * | |
270 | * This function returns 1 if the aggregated constraint value has changed, 0 | |
271 | * otherwise. | |
272 | */ | |
273 | int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, | |
274 | enum pm_qos_req_action action, int value) | |
d82b3518 | 275 | { |
d82b3518 | 276 | unsigned long flags; |
abe98ec2 | 277 | int prev_value, curr_value, new_value; |
2d984ad1 | 278 | int ret; |
d82b3518 MG |
279 | |
280 | spin_lock_irqsave(&pm_qos_lock, flags); | |
abe98ec2 JP |
281 | prev_value = pm_qos_get_value(c); |
282 | if (value == PM_QOS_DEFAULT_VALUE) | |
283 | new_value = c->default_value; | |
284 | else | |
285 | new_value = value; | |
286 | ||
287 | switch (action) { | |
288 | case PM_QOS_REMOVE_REQ: | |
289 | plist_del(node, &c->list); | |
290 | break; | |
291 | case PM_QOS_UPDATE_REQ: | |
5f279845 JB |
292 | /* |
293 | * to change the list, we atomically remove, reinit | |
294 | * with new value and add, then see if the extremal | |
295 | * changed | |
296 | */ | |
abe98ec2 | 297 | plist_del(node, &c->list); |
fe43e2ce | 298 | /* fall through */ |
abe98ec2 JP |
299 | case PM_QOS_ADD_REQ: |
300 | plist_node_init(node, new_value); | |
301 | plist_add(node, &c->list); | |
302 | break; | |
303 | default: | |
304 | /* no action */ | |
305 | ; | |
d82b3518 | 306 | } |
abe98ec2 JP |
307 | |
308 | curr_value = pm_qos_get_value(c); | |
309 | pm_qos_set_value(c, curr_value); | |
310 | ||
d82b3518 MG |
311 | spin_unlock_irqrestore(&pm_qos_lock, flags); |
312 | ||
247e9ee0 | 313 | trace_pm_qos_update_target(action, prev_value, curr_value); |
abe98ec2 | 314 | if (prev_value != curr_value) { |
2d984ad1 RW |
315 | ret = 1; |
316 | if (c->notifiers) | |
317 | blocking_notifier_call_chain(c->notifiers, | |
318 | (unsigned long)curr_value, | |
319 | NULL); | |
abe98ec2 | 320 | } else { |
2d984ad1 | 321 | ret = 0; |
abe98ec2 | 322 | } |
2d984ad1 | 323 | return ret; |
d82b3518 MG |
324 | } |
325 | ||
5efbe427 RW |
326 | /** |
327 | * pm_qos_flags_remove_req - Remove device PM QoS flags request. | |
328 | * @pqf: Device PM QoS flags set to remove the request from. | |
329 | * @req: Request to remove from the set. | |
330 | */ | |
331 | static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf, | |
332 | struct pm_qos_flags_request *req) | |
333 | { | |
334 | s32 val = 0; | |
335 | ||
336 | list_del(&req->node); | |
337 | list_for_each_entry(req, &pqf->list, node) | |
338 | val |= req->flags; | |
339 | ||
340 | pqf->effective_flags = val; | |
341 | } | |
342 | ||
343 | /** | |
344 | * pm_qos_update_flags - Update a set of PM QoS flags. | |
345 | * @pqf: Set of flags to update. | |
346 | * @req: Request to add to the set, to modify, or to remove from the set. | |
347 | * @action: Action to take on the set. | |
348 | * @val: Value of the request to add or modify. | |
349 | * | |
350 | * Update the given set of PM QoS flags and call notifiers if the aggregate | |
351 | * value has changed. Returns 1 if the aggregate constraint value has changed, | |
352 | * 0 otherwise. | |
353 | */ | |
354 | bool pm_qos_update_flags(struct pm_qos_flags *pqf, | |
355 | struct pm_qos_flags_request *req, | |
356 | enum pm_qos_req_action action, s32 val) | |
357 | { | |
358 | unsigned long irqflags; | |
359 | s32 prev_value, curr_value; | |
360 | ||
361 | spin_lock_irqsave(&pm_qos_lock, irqflags); | |
362 | ||
363 | prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; | |
364 | ||
365 | switch (action) { | |
366 | case PM_QOS_REMOVE_REQ: | |
367 | pm_qos_flags_remove_req(pqf, req); | |
368 | break; | |
369 | case PM_QOS_UPDATE_REQ: | |
370 | pm_qos_flags_remove_req(pqf, req); | |
fe43e2ce | 371 | /* fall through */ |
5efbe427 RW |
372 | case PM_QOS_ADD_REQ: |
373 | req->flags = val; | |
374 | INIT_LIST_HEAD(&req->node); | |
375 | list_add_tail(&req->node, &pqf->list); | |
376 | pqf->effective_flags |= val; | |
377 | break; | |
378 | default: | |
379 | /* no action */ | |
380 | ; | |
381 | } | |
382 | ||
383 | curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; | |
384 | ||
385 | spin_unlock_irqrestore(&pm_qos_lock, irqflags); | |
386 | ||
247e9ee0 | 387 | trace_pm_qos_update_flags(action, prev_value, curr_value); |
5efbe427 RW |
388 | return prev_value != curr_value; |
389 | } | |
390 | ||
d82b3518 | 391 | /** |
ed77134b | 392 | * pm_qos_request - returns current system wide qos expectation |
d82b3518 MG |
393 | * @pm_qos_class: identification of which qos value is requested |
394 | * | |
333c5ae9 | 395 | * This function returns the current target value. |
d82b3518 | 396 | */ |
ed77134b | 397 | int pm_qos_request(int pm_qos_class) |
d82b3518 | 398 | { |
abe98ec2 | 399 | return pm_qos_read_value(pm_qos_array[pm_qos_class]->constraints); |
d82b3518 | 400 | } |
ed77134b | 401 | EXPORT_SYMBOL_GPL(pm_qos_request); |
d82b3518 | 402 | |
cc749986 | 403 | int pm_qos_request_active(struct pm_qos_request *req) |
82f68251 JB |
404 | { |
405 | return req->pm_qos_class != 0; | |
406 | } | |
407 | EXPORT_SYMBOL_GPL(pm_qos_request_active); | |
408 | ||
40fea92f SB |
409 | static void __pm_qos_update_request(struct pm_qos_request *req, |
410 | s32 new_value) | |
411 | { | |
412 | trace_pm_qos_update_request(req->pm_qos_class, new_value); | |
413 | ||
414 | if (new_value != req->node.prio) | |
415 | pm_qos_update_target( | |
416 | pm_qos_array[req->pm_qos_class]->constraints, | |
417 | &req->node, PM_QOS_UPDATE_REQ, new_value); | |
418 | } | |
419 | ||
c4772d19 MH |
420 | /** |
421 | * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout | |
422 | * @work: work struct for the delayed work (timeout) | |
423 | * | |
424 | * This cancels the timeout request by falling back to the default at timeout. | |
425 | */ | |
426 | static void pm_qos_work_fn(struct work_struct *work) | |
427 | { | |
428 | struct pm_qos_request *req = container_of(to_delayed_work(work), | |
429 | struct pm_qos_request, | |
430 | work); | |
431 | ||
40fea92f | 432 | __pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE); |
c4772d19 MH |
433 | } |
434 | ||
d82b3518 | 435 | /** |
ed77134b | 436 | * pm_qos_add_request - inserts new qos request into the list |
cc749986 | 437 | * @req: pointer to a preallocated handle |
25cc69ec | 438 | * @pm_qos_class: identifies which list of qos request to use |
d82b3518 MG |
439 | * @value: defines the qos request |
440 | * | |
441 | * This function inserts a new entry in the pm_qos_class list of requested qos | |
bf1db69f | 442 | * performance characteristics. It recomputes the aggregate QoS expectations |
cc749986 | 443 | * for the pm_qos_class of parameters and initializes the pm_qos_request |
25cc69ec SK |
444 | * handle. Caller needs to save this handle for later use in updates and |
445 | * removal. | |
d82b3518 | 446 | */ |
25cc69ec | 447 | |
cc749986 | 448 | void pm_qos_add_request(struct pm_qos_request *req, |
82f68251 | 449 | int pm_qos_class, s32 value) |
d82b3518 | 450 | { |
abe98ec2 JP |
451 | if (!req) /*guard against callers passing in null */ |
452 | return; | |
d82b3518 | 453 | |
cc749986 | 454 | if (pm_qos_request_active(req)) { |
82f68251 JB |
455 | WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); |
456 | return; | |
457 | } | |
cc749986 | 458 | req->pm_qos_class = pm_qos_class; |
c4772d19 | 459 | INIT_DELAYED_WORK(&req->work, pm_qos_work_fn); |
ae8822b8 | 460 | trace_pm_qos_add_request(pm_qos_class, value); |
abe98ec2 JP |
461 | pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, |
462 | &req->node, PM_QOS_ADD_REQ, value); | |
d82b3518 | 463 | } |
ed77134b | 464 | EXPORT_SYMBOL_GPL(pm_qos_add_request); |
d82b3518 MG |
465 | |
466 | /** | |
ed77134b | 467 | * pm_qos_update_request - modifies an existing qos request |
cc749986 | 468 | * @req : handle to list element holding a pm_qos request to use |
d82b3518 MG |
469 | * @value: defines the qos request |
470 | * | |
ed77134b | 471 | * Updates an existing qos request for the pm_qos_class of parameters along |
d82b3518 MG |
472 | * with updating the target pm_qos_class value. |
473 | * | |
ed77134b | 474 | * Attempts are made to make this code callable on hot code paths. |
d82b3518 | 475 | */ |
cc749986 | 476 | void pm_qos_update_request(struct pm_qos_request *req, |
5f279845 | 477 | s32 new_value) |
d82b3518 | 478 | { |
cc749986 | 479 | if (!req) /*guard against callers passing in null */ |
5f279845 JB |
480 | return; |
481 | ||
cc749986 | 482 | if (!pm_qos_request_active(req)) { |
82f68251 JB |
483 | WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n"); |
484 | return; | |
485 | } | |
486 | ||
a81f80f3 | 487 | cancel_delayed_work_sync(&req->work); |
40fea92f | 488 | __pm_qos_update_request(req, new_value); |
d82b3518 | 489 | } |
ed77134b | 490 | EXPORT_SYMBOL_GPL(pm_qos_update_request); |
d82b3518 | 491 | |
c4772d19 MH |
492 | /** |
493 | * pm_qos_update_request_timeout - modifies an existing qos request temporarily. | |
494 | * @req : handle to list element holding a pm_qos request to use | |
495 | * @new_value: defines the temporal qos request | |
496 | * @timeout_us: the effective duration of this qos request in usecs. | |
497 | * | |
498 | * After timeout_us, this qos request is cancelled automatically. | |
499 | */ | |
500 | void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, | |
501 | unsigned long timeout_us) | |
502 | { | |
503 | if (!req) | |
504 | return; | |
505 | if (WARN(!pm_qos_request_active(req), | |
506 | "%s called for unknown object.", __func__)) | |
507 | return; | |
508 | ||
ed1ac6e9 | 509 | cancel_delayed_work_sync(&req->work); |
c4772d19 | 510 | |
ae8822b8 S |
511 | trace_pm_qos_update_request_timeout(req->pm_qos_class, |
512 | new_value, timeout_us); | |
c4772d19 MH |
513 | if (new_value != req->node.prio) |
514 | pm_qos_update_target( | |
515 | pm_qos_array[req->pm_qos_class]->constraints, | |
516 | &req->node, PM_QOS_UPDATE_REQ, new_value); | |
517 | ||
518 | schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us)); | |
519 | } | |
520 | ||
d82b3518 | 521 | /** |
ed77134b | 522 | * pm_qos_remove_request - modifies an existing qos request |
cc749986 | 523 | * @req: handle to request list element |
d82b3518 | 524 | * |
cc749986 | 525 | * Will remove pm qos request from the list of constraints and |
ed77134b MG |
526 | * recompute the current target value for the pm_qos_class. Call this |
527 | * on slow code paths. | |
d82b3518 | 528 | */ |
cc749986 | 529 | void pm_qos_remove_request(struct pm_qos_request *req) |
d82b3518 | 530 | { |
abe98ec2 | 531 | if (!req) /*guard against callers passing in null */ |
ed77134b MG |
532 | return; |
533 | /* silent return to keep pcm code cleaner */ | |
d82b3518 | 534 | |
cc749986 | 535 | if (!pm_qos_request_active(req)) { |
82f68251 JB |
536 | WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n"); |
537 | return; | |
538 | } | |
539 | ||
ed1ac6e9 | 540 | cancel_delayed_work_sync(&req->work); |
c4772d19 | 541 | |
ae8822b8 | 542 | trace_pm_qos_remove_request(req->pm_qos_class, PM_QOS_DEFAULT_VALUE); |
abe98ec2 JP |
543 | pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, |
544 | &req->node, PM_QOS_REMOVE_REQ, | |
545 | PM_QOS_DEFAULT_VALUE); | |
cc749986 | 546 | memset(req, 0, sizeof(*req)); |
d82b3518 | 547 | } |
ed77134b | 548 | EXPORT_SYMBOL_GPL(pm_qos_remove_request); |
d82b3518 MG |
549 | |
550 | /** | |
551 | * pm_qos_add_notifier - sets notification entry for changes to target value | |
552 | * @pm_qos_class: identifies which qos target changes should be notified. | |
553 | * @notifier: notifier block managed by caller. | |
554 | * | |
555 | * will register the notifier into a notification chain that gets called | |
bf1db69f | 556 | * upon changes to the pm_qos_class target value. |
d82b3518 | 557 | */ |
ed77134b | 558 | int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) |
d82b3518 MG |
559 | { |
560 | int retval; | |
561 | ||
562 | retval = blocking_notifier_chain_register( | |
4e1779ba JP |
563 | pm_qos_array[pm_qos_class]->constraints->notifiers, |
564 | notifier); | |
d82b3518 MG |
565 | |
566 | return retval; | |
567 | } | |
568 | EXPORT_SYMBOL_GPL(pm_qos_add_notifier); | |
569 | ||
570 | /** | |
571 | * pm_qos_remove_notifier - deletes notification entry from chain. | |
572 | * @pm_qos_class: identifies which qos target changes are notified. | |
573 | * @notifier: notifier block to be removed. | |
574 | * | |
575 | * will remove the notifier from the notification chain that gets called | |
bf1db69f | 576 | * upon changes to the pm_qos_class target value. |
d82b3518 MG |
577 | */ |
578 | int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) | |
579 | { | |
580 | int retval; | |
581 | ||
582 | retval = blocking_notifier_chain_unregister( | |
4e1779ba JP |
583 | pm_qos_array[pm_qos_class]->constraints->notifiers, |
584 | notifier); | |
d82b3518 MG |
585 | |
586 | return retval; | |
587 | } | |
588 | EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); | |
589 | ||
4a31a334 | 590 | /* User space interface to PM QoS classes via misc devices */ |
f5f4eda4 | 591 | static int register_pm_qos_misc(struct pm_qos_object *qos, struct dentry *d) |
4a31a334 JP |
592 | { |
593 | qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR; | |
594 | qos->pm_qos_power_miscdev.name = qos->name; | |
595 | qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops; | |
596 | ||
f5f4eda4 NM |
597 | if (d) { |
598 | (void)debugfs_create_file(qos->name, S_IRUGO, d, | |
599 | (void *)qos, &pm_qos_debug_fops); | |
600 | } | |
601 | ||
4a31a334 JP |
602 | return misc_register(&qos->pm_qos_power_miscdev); |
603 | } | |
604 | ||
605 | static int find_pm_qos_object_by_minor(int minor) | |
606 | { | |
607 | int pm_qos_class; | |
608 | ||
d24c2a4f | 609 | for (pm_qos_class = PM_QOS_CPU_DMA_LATENCY; |
4a31a334 JP |
610 | pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) { |
611 | if (minor == | |
612 | pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor) | |
613 | return pm_qos_class; | |
614 | } | |
615 | return -1; | |
616 | } | |
617 | ||
d82b3518 MG |
618 | static int pm_qos_power_open(struct inode *inode, struct file *filp) |
619 | { | |
d82b3518 MG |
620 | long pm_qos_class; |
621 | ||
622 | pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); | |
d24c2a4f | 623 | if (pm_qos_class >= PM_QOS_CPU_DMA_LATENCY) { |
cc749986 | 624 | struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL); |
82f68251 JB |
625 | if (!req) |
626 | return -ENOMEM; | |
627 | ||
628 | pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE); | |
629 | filp->private_data = req; | |
ed77134b | 630 | |
6513fd69 | 631 | return 0; |
d82b3518 | 632 | } |
d82b3518 MG |
633 | return -EPERM; |
634 | } | |
635 | ||
636 | static int pm_qos_power_release(struct inode *inode, struct file *filp) | |
637 | { | |
cc749986 | 638 | struct pm_qos_request *req; |
d82b3518 | 639 | |
82f68251 | 640 | req = filp->private_data; |
ed77134b | 641 | pm_qos_remove_request(req); |
82f68251 | 642 | kfree(req); |
d82b3518 MG |
643 | |
644 | return 0; | |
645 | } | |
646 | ||
ed77134b | 647 | |
f9b9e806 TR |
648 | static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, |
649 | size_t count, loff_t *f_pos) | |
650 | { | |
651 | s32 value; | |
652 | unsigned long flags; | |
cc749986 | 653 | struct pm_qos_request *req = filp->private_data; |
f9b9e806 | 654 | |
cc749986 | 655 | if (!req) |
f9b9e806 | 656 | return -EINVAL; |
cc749986 | 657 | if (!pm_qos_request_active(req)) |
f9b9e806 TR |
658 | return -EINVAL; |
659 | ||
f9b9e806 | 660 | spin_lock_irqsave(&pm_qos_lock, flags); |
abe98ec2 | 661 | value = pm_qos_get_value(pm_qos_array[req->pm_qos_class]->constraints); |
f9b9e806 TR |
662 | spin_unlock_irqrestore(&pm_qos_lock, flags); |
663 | ||
664 | return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32)); | |
665 | } | |
666 | ||
d82b3518 MG |
667 | static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, |
668 | size_t count, loff_t *f_pos) | |
669 | { | |
670 | s32 value; | |
cc749986 | 671 | struct pm_qos_request *req; |
ed77134b MG |
672 | |
673 | if (count == sizeof(s32)) { | |
674 | if (copy_from_user(&value, buf, sizeof(s32))) | |
675 | return -EFAULT; | |
d4f7ecf7 | 676 | } else { |
0775a60a RW |
677 | int ret; |
678 | ||
d4f7ecf7 AS |
679 | ret = kstrtos32_from_user(buf, count, 16, &value); |
680 | if (ret) | |
681 | return ret; | |
0775a60a | 682 | } |
d82b3518 | 683 | |
cc749986 JP |
684 | req = filp->private_data; |
685 | pm_qos_update_request(req, value); | |
ed77134b MG |
686 | |
687 | return count; | |
d82b3518 MG |
688 | } |
689 | ||
690 | ||
691 | static int __init pm_qos_power_init(void) | |
692 | { | |
693 | int ret = 0; | |
d031e1de | 694 | int i; |
f5f4eda4 | 695 | struct dentry *d; |
d82b3518 | 696 | |
d031e1de AF |
697 | BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES); |
698 | ||
f5f4eda4 NM |
699 | d = debugfs_create_dir("pm_qos", NULL); |
700 | if (IS_ERR_OR_NULL(d)) | |
701 | d = NULL; | |
702 | ||
d24c2a4f | 703 | for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) { |
f5f4eda4 | 704 | ret = register_pm_qos_misc(pm_qos_array[i], d); |
d031e1de | 705 | if (ret < 0) { |
64ec72a1 JP |
706 | pr_err("%s: %s setup failed\n", |
707 | __func__, pm_qos_array[i]->name); | |
d031e1de AF |
708 | return ret; |
709 | } | |
d82b3518 | 710 | } |
d82b3518 MG |
711 | |
712 | return ret; | |
713 | } | |
714 | ||
715 | late_initcall(pm_qos_power_init); |