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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
d82b3518 MG |
2 | /* |
3 | * This module exposes the interface to kernel space for specifying | |
4 | * QoS dependencies. It provides infrastructure for registration of: | |
5 | * | |
ed77134b | 6 | * Dependents on a QoS value : register requests |
d82b3518 MG |
7 | * Watchers of QoS value : get notified when target QoS value changes |
8 | * | |
9 | * This QoS design is best effort based. Dependents register their QoS needs. | |
10 | * Watchers register to keep track of the current QoS needs of the system. | |
11 | * | |
12 | * There are 3 basic classes of QoS parameter: latency, timeout, throughput | |
13 | * each have defined units: | |
14 | * latency: usec | |
15 | * timeout: usec <-- currently not used. | |
16 | * throughput: kbs (kilo byte / sec) | |
17 | * | |
ed77134b | 18 | * There are lists of pm_qos_objects each one wrapping requests, notifiers |
d82b3518 | 19 | * |
ed77134b | 20 | * User mode requests on a QOS parameter register themselves to the |
d82b3518 MG |
21 | * subsystem by opening the device node /dev/... and writing there request to |
22 | * the node. As long as the process holds a file handle open to the node the | |
23 | * client continues to be accounted for. Upon file release the usermode | |
ed77134b MG |
24 | * request is removed and a new qos target is computed. This way when the |
25 | * request that the application has is cleaned up when closes the file | |
d82b3518 MG |
26 | * pointer or exits the pm_qos_object will get an opportunity to clean up. |
27 | * | |
bf1db69f | 28 | * Mark Gross <mgross@linux.intel.com> |
d82b3518 MG |
29 | */ |
30 | ||
ed77134b MG |
31 | /*#define DEBUG*/ |
32 | ||
e8db0be1 | 33 | #include <linux/pm_qos.h> |
d82b3518 MG |
34 | #include <linux/sched.h> |
35 | #include <linux/spinlock.h> | |
36 | #include <linux/slab.h> | |
37 | #include <linux/time.h> | |
38 | #include <linux/fs.h> | |
39 | #include <linux/device.h> | |
40 | #include <linux/miscdevice.h> | |
41 | #include <linux/string.h> | |
42 | #include <linux/platform_device.h> | |
43 | #include <linux/init.h> | |
0775a60a | 44 | #include <linux/kernel.h> |
f5f4eda4 NM |
45 | #include <linux/debugfs.h> |
46 | #include <linux/seq_file.h> | |
d82b3518 MG |
47 | |
48 | #include <linux/uaccess.h> | |
6e5fdeed | 49 | #include <linux/export.h> |
247e9ee0 | 50 | #include <trace/events/power.h> |
d82b3518 MG |
51 | |
52 | /* | |
cc749986 | 53 | * locking rule: all changes to constraints or notifiers lists |
d82b3518 MG |
54 | * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock |
55 | * held, taken with _irqsave. One lock to rule them all | |
56 | */ | |
d82b3518 | 57 | struct pm_qos_object { |
4e1779ba | 58 | struct pm_qos_constraints *constraints; |
d82b3518 MG |
59 | struct miscdevice pm_qos_power_miscdev; |
60 | char *name; | |
d82b3518 MG |
61 | }; |
62 | ||
5f279845 JB |
63 | static DEFINE_SPINLOCK(pm_qos_lock); |
64 | ||
d82b3518 | 65 | static struct pm_qos_object null_pm_qos; |
4e1779ba | 66 | |
d82b3518 | 67 | static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); |
4e1779ba JP |
68 | static struct pm_qos_constraints cpu_dma_constraints = { |
69 | .list = PLIST_HEAD_INIT(cpu_dma_constraints.list), | |
333c5ae9 TC |
70 | .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, |
71 | .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, | |
327adaed | 72 | .no_constraint_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, |
5f279845 | 73 | .type = PM_QOS_MIN, |
4e1779ba JP |
74 | .notifiers = &cpu_dma_lat_notifier, |
75 | }; | |
76 | static struct pm_qos_object cpu_dma_pm_qos = { | |
77 | .constraints = &cpu_dma_constraints, | |
a6f05b97 | 78 | .name = "cpu_dma_latency", |
d82b3518 MG |
79 | }; |
80 | ||
81 | static BLOCKING_NOTIFIER_HEAD(network_lat_notifier); | |
4e1779ba JP |
82 | static struct pm_qos_constraints network_lat_constraints = { |
83 | .list = PLIST_HEAD_INIT(network_lat_constraints.list), | |
333c5ae9 TC |
84 | .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, |
85 | .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, | |
327adaed | 86 | .no_constraint_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, |
4e1779ba JP |
87 | .type = PM_QOS_MIN, |
88 | .notifiers = &network_lat_notifier, | |
89 | }; | |
90 | static struct pm_qos_object network_lat_pm_qos = { | |
91 | .constraints = &network_lat_constraints, | |
92 | .name = "network_latency", | |
d82b3518 MG |
93 | }; |
94 | ||
95 | ||
96 | static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier); | |
4e1779ba JP |
97 | static struct pm_qos_constraints network_tput_constraints = { |
98 | .list = PLIST_HEAD_INIT(network_tput_constraints.list), | |
333c5ae9 TC |
99 | .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, |
100 | .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, | |
327adaed | 101 | .no_constraint_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, |
5f279845 | 102 | .type = PM_QOS_MAX, |
4e1779ba JP |
103 | .notifiers = &network_throughput_notifier, |
104 | }; | |
105 | static struct pm_qos_object network_throughput_pm_qos = { | |
106 | .constraints = &network_tput_constraints, | |
107 | .name = "network_throughput", | |
d82b3518 MG |
108 | }; |
109 | ||
110 | ||
7990da71 TV |
111 | static BLOCKING_NOTIFIER_HEAD(memory_bandwidth_notifier); |
112 | static struct pm_qos_constraints memory_bw_constraints = { | |
113 | .list = PLIST_HEAD_INIT(memory_bw_constraints.list), | |
114 | .target_value = PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE, | |
115 | .default_value = PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE, | |
116 | .no_constraint_value = PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE, | |
117 | .type = PM_QOS_SUM, | |
118 | .notifiers = &memory_bandwidth_notifier, | |
119 | }; | |
120 | static struct pm_qos_object memory_bandwidth_pm_qos = { | |
121 | .constraints = &memory_bw_constraints, | |
122 | .name = "memory_bandwidth", | |
123 | }; | |
124 | ||
125 | ||
d82b3518 MG |
126 | static struct pm_qos_object *pm_qos_array[] = { |
127 | &null_pm_qos, | |
128 | &cpu_dma_pm_qos, | |
129 | &network_lat_pm_qos, | |
7990da71 TV |
130 | &network_throughput_pm_qos, |
131 | &memory_bandwidth_pm_qos, | |
d82b3518 MG |
132 | }; |
133 | ||
d82b3518 MG |
134 | static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, |
135 | size_t count, loff_t *f_pos); | |
f9b9e806 TR |
136 | static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, |
137 | size_t count, loff_t *f_pos); | |
d82b3518 MG |
138 | static int pm_qos_power_open(struct inode *inode, struct file *filp); |
139 | static int pm_qos_power_release(struct inode *inode, struct file *filp); | |
140 | ||
141 | static const struct file_operations pm_qos_power_fops = { | |
142 | .write = pm_qos_power_write, | |
f9b9e806 | 143 | .read = pm_qos_power_read, |
d82b3518 MG |
144 | .open = pm_qos_power_open, |
145 | .release = pm_qos_power_release, | |
6038f373 | 146 | .llseek = noop_llseek, |
d82b3518 MG |
147 | }; |
148 | ||
5f279845 | 149 | /* unlocked internal variant */ |
abe98ec2 | 150 | static inline int pm_qos_get_value(struct pm_qos_constraints *c) |
d82b3518 | 151 | { |
7990da71 TV |
152 | struct plist_node *node; |
153 | int total_value = 0; | |
154 | ||
abe98ec2 | 155 | if (plist_head_empty(&c->list)) |
327adaed | 156 | return c->no_constraint_value; |
d82b3518 | 157 | |
abe98ec2 | 158 | switch (c->type) { |
5f279845 | 159 | case PM_QOS_MIN: |
abe98ec2 | 160 | return plist_first(&c->list)->prio; |
d82b3518 | 161 | |
5f279845 | 162 | case PM_QOS_MAX: |
abe98ec2 | 163 | return plist_last(&c->list)->prio; |
d82b3518 | 164 | |
7990da71 TV |
165 | case PM_QOS_SUM: |
166 | plist_for_each(node, &c->list) | |
167 | total_value += node->prio; | |
168 | ||
169 | return total_value; | |
170 | ||
5f279845 JB |
171 | default: |
172 | /* runtime check for not using enum */ | |
173 | BUG(); | |
c6a57bff | 174 | return PM_QOS_DEFAULT_VALUE; |
5f279845 JB |
175 | } |
176 | } | |
177 | ||
b66213cd | 178 | s32 pm_qos_read_value(struct pm_qos_constraints *c) |
333c5ae9 | 179 | { |
abe98ec2 | 180 | return c->target_value; |
333c5ae9 TC |
181 | } |
182 | ||
abe98ec2 | 183 | static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) |
333c5ae9 | 184 | { |
abe98ec2 | 185 | c->target_value = value; |
333c5ae9 TC |
186 | } |
187 | ||
96c69352 | 188 | static int pm_qos_debug_show(struct seq_file *s, void *unused) |
f5f4eda4 NM |
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 | ||
96c69352 | 249 | DEFINE_SHOW_ATTRIBUTE(pm_qos_debug); |
f5f4eda4 | 250 | |
abe98ec2 JP |
251 | /** |
252 | * pm_qos_update_target - manages the constraints list and calls the notifiers | |
253 | * if needed | |
254 | * @c: constraints data struct | |
255 | * @node: request to add to the list, to update or to remove | |
256 | * @action: action to take on the constraints list | |
257 | * @value: value of the request to add or update | |
258 | * | |
259 | * This function returns 1 if the aggregated constraint value has changed, 0 | |
260 | * otherwise. | |
261 | */ | |
262 | int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, | |
263 | enum pm_qos_req_action action, int value) | |
d82b3518 | 264 | { |
d82b3518 | 265 | unsigned long flags; |
abe98ec2 | 266 | int prev_value, curr_value, new_value; |
2d984ad1 | 267 | int ret; |
d82b3518 MG |
268 | |
269 | spin_lock_irqsave(&pm_qos_lock, flags); | |
abe98ec2 JP |
270 | prev_value = pm_qos_get_value(c); |
271 | if (value == PM_QOS_DEFAULT_VALUE) | |
272 | new_value = c->default_value; | |
273 | else | |
274 | new_value = value; | |
275 | ||
276 | switch (action) { | |
277 | case PM_QOS_REMOVE_REQ: | |
278 | plist_del(node, &c->list); | |
279 | break; | |
280 | case PM_QOS_UPDATE_REQ: | |
5f279845 JB |
281 | /* |
282 | * to change the list, we atomically remove, reinit | |
283 | * with new value and add, then see if the extremal | |
284 | * changed | |
285 | */ | |
abe98ec2 | 286 | plist_del(node, &c->list); |
fe43e2ce | 287 | /* fall through */ |
abe98ec2 JP |
288 | case PM_QOS_ADD_REQ: |
289 | plist_node_init(node, new_value); | |
290 | plist_add(node, &c->list); | |
291 | break; | |
292 | default: | |
293 | /* no action */ | |
294 | ; | |
d82b3518 | 295 | } |
abe98ec2 JP |
296 | |
297 | curr_value = pm_qos_get_value(c); | |
298 | pm_qos_set_value(c, curr_value); | |
299 | ||
d82b3518 MG |
300 | spin_unlock_irqrestore(&pm_qos_lock, flags); |
301 | ||
247e9ee0 | 302 | trace_pm_qos_update_target(action, prev_value, curr_value); |
abe98ec2 | 303 | if (prev_value != curr_value) { |
2d984ad1 RW |
304 | ret = 1; |
305 | if (c->notifiers) | |
306 | blocking_notifier_call_chain(c->notifiers, | |
307 | (unsigned long)curr_value, | |
308 | NULL); | |
abe98ec2 | 309 | } else { |
2d984ad1 | 310 | ret = 0; |
abe98ec2 | 311 | } |
2d984ad1 | 312 | return ret; |
d82b3518 MG |
313 | } |
314 | ||
5efbe427 RW |
315 | /** |
316 | * pm_qos_flags_remove_req - Remove device PM QoS flags request. | |
317 | * @pqf: Device PM QoS flags set to remove the request from. | |
318 | * @req: Request to remove from the set. | |
319 | */ | |
320 | static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf, | |
321 | struct pm_qos_flags_request *req) | |
322 | { | |
323 | s32 val = 0; | |
324 | ||
325 | list_del(&req->node); | |
326 | list_for_each_entry(req, &pqf->list, node) | |
327 | val |= req->flags; | |
328 | ||
329 | pqf->effective_flags = val; | |
330 | } | |
331 | ||
332 | /** | |
333 | * pm_qos_update_flags - Update a set of PM QoS flags. | |
334 | * @pqf: Set of flags to update. | |
335 | * @req: Request to add to the set, to modify, or to remove from the set. | |
336 | * @action: Action to take on the set. | |
337 | * @val: Value of the request to add or modify. | |
338 | * | |
339 | * Update the given set of PM QoS flags and call notifiers if the aggregate | |
340 | * value has changed. Returns 1 if the aggregate constraint value has changed, | |
341 | * 0 otherwise. | |
342 | */ | |
343 | bool pm_qos_update_flags(struct pm_qos_flags *pqf, | |
344 | struct pm_qos_flags_request *req, | |
345 | enum pm_qos_req_action action, s32 val) | |
346 | { | |
347 | unsigned long irqflags; | |
348 | s32 prev_value, curr_value; | |
349 | ||
350 | spin_lock_irqsave(&pm_qos_lock, irqflags); | |
351 | ||
352 | prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; | |
353 | ||
354 | switch (action) { | |
355 | case PM_QOS_REMOVE_REQ: | |
356 | pm_qos_flags_remove_req(pqf, req); | |
357 | break; | |
358 | case PM_QOS_UPDATE_REQ: | |
359 | pm_qos_flags_remove_req(pqf, req); | |
fe43e2ce | 360 | /* fall through */ |
5efbe427 RW |
361 | case PM_QOS_ADD_REQ: |
362 | req->flags = val; | |
363 | INIT_LIST_HEAD(&req->node); | |
364 | list_add_tail(&req->node, &pqf->list); | |
365 | pqf->effective_flags |= val; | |
366 | break; | |
367 | default: | |
368 | /* no action */ | |
369 | ; | |
370 | } | |
371 | ||
372 | curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; | |
373 | ||
374 | spin_unlock_irqrestore(&pm_qos_lock, irqflags); | |
375 | ||
247e9ee0 | 376 | trace_pm_qos_update_flags(action, prev_value, curr_value); |
5efbe427 RW |
377 | return prev_value != curr_value; |
378 | } | |
379 | ||
d82b3518 | 380 | /** |
ed77134b | 381 | * pm_qos_request - returns current system wide qos expectation |
d82b3518 MG |
382 | * @pm_qos_class: identification of which qos value is requested |
383 | * | |
333c5ae9 | 384 | * This function returns the current target value. |
d82b3518 | 385 | */ |
ed77134b | 386 | int pm_qos_request(int pm_qos_class) |
d82b3518 | 387 | { |
abe98ec2 | 388 | return pm_qos_read_value(pm_qos_array[pm_qos_class]->constraints); |
d82b3518 | 389 | } |
ed77134b | 390 | EXPORT_SYMBOL_GPL(pm_qos_request); |
d82b3518 | 391 | |
cc749986 | 392 | int pm_qos_request_active(struct pm_qos_request *req) |
82f68251 JB |
393 | { |
394 | return req->pm_qos_class != 0; | |
395 | } | |
396 | EXPORT_SYMBOL_GPL(pm_qos_request_active); | |
397 | ||
40fea92f SB |
398 | static void __pm_qos_update_request(struct pm_qos_request *req, |
399 | s32 new_value) | |
400 | { | |
401 | trace_pm_qos_update_request(req->pm_qos_class, new_value); | |
402 | ||
403 | if (new_value != req->node.prio) | |
404 | pm_qos_update_target( | |
405 | pm_qos_array[req->pm_qos_class]->constraints, | |
406 | &req->node, PM_QOS_UPDATE_REQ, new_value); | |
407 | } | |
408 | ||
c4772d19 MH |
409 | /** |
410 | * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout | |
411 | * @work: work struct for the delayed work (timeout) | |
412 | * | |
413 | * This cancels the timeout request by falling back to the default at timeout. | |
414 | */ | |
415 | static void pm_qos_work_fn(struct work_struct *work) | |
416 | { | |
417 | struct pm_qos_request *req = container_of(to_delayed_work(work), | |
418 | struct pm_qos_request, | |
419 | work); | |
420 | ||
40fea92f | 421 | __pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE); |
c4772d19 MH |
422 | } |
423 | ||
d82b3518 | 424 | /** |
ed77134b | 425 | * pm_qos_add_request - inserts new qos request into the list |
cc749986 | 426 | * @req: pointer to a preallocated handle |
25cc69ec | 427 | * @pm_qos_class: identifies which list of qos request to use |
d82b3518 MG |
428 | * @value: defines the qos request |
429 | * | |
430 | * This function inserts a new entry in the pm_qos_class list of requested qos | |
bf1db69f | 431 | * performance characteristics. It recomputes the aggregate QoS expectations |
cc749986 | 432 | * for the pm_qos_class of parameters and initializes the pm_qos_request |
25cc69ec SK |
433 | * handle. Caller needs to save this handle for later use in updates and |
434 | * removal. | |
d82b3518 | 435 | */ |
25cc69ec | 436 | |
cc749986 | 437 | void pm_qos_add_request(struct pm_qos_request *req, |
82f68251 | 438 | int pm_qos_class, s32 value) |
d82b3518 | 439 | { |
abe98ec2 JP |
440 | if (!req) /*guard against callers passing in null */ |
441 | return; | |
d82b3518 | 442 | |
cc749986 | 443 | if (pm_qos_request_active(req)) { |
82f68251 JB |
444 | WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); |
445 | return; | |
446 | } | |
cc749986 | 447 | req->pm_qos_class = pm_qos_class; |
c4772d19 | 448 | INIT_DELAYED_WORK(&req->work, pm_qos_work_fn); |
ae8822b8 | 449 | trace_pm_qos_add_request(pm_qos_class, value); |
abe98ec2 JP |
450 | pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, |
451 | &req->node, PM_QOS_ADD_REQ, value); | |
d82b3518 | 452 | } |
ed77134b | 453 | EXPORT_SYMBOL_GPL(pm_qos_add_request); |
d82b3518 MG |
454 | |
455 | /** | |
ed77134b | 456 | * pm_qos_update_request - modifies an existing qos request |
cc749986 | 457 | * @req : handle to list element holding a pm_qos request to use |
d82b3518 MG |
458 | * @value: defines the qos request |
459 | * | |
ed77134b | 460 | * Updates an existing qos request for the pm_qos_class of parameters along |
d82b3518 MG |
461 | * with updating the target pm_qos_class value. |
462 | * | |
ed77134b | 463 | * Attempts are made to make this code callable on hot code paths. |
d82b3518 | 464 | */ |
cc749986 | 465 | void pm_qos_update_request(struct pm_qos_request *req, |
5f279845 | 466 | s32 new_value) |
d82b3518 | 467 | { |
cc749986 | 468 | if (!req) /*guard against callers passing in null */ |
5f279845 JB |
469 | return; |
470 | ||
cc749986 | 471 | if (!pm_qos_request_active(req)) { |
82f68251 JB |
472 | WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n"); |
473 | return; | |
474 | } | |
475 | ||
a81f80f3 | 476 | cancel_delayed_work_sync(&req->work); |
40fea92f | 477 | __pm_qos_update_request(req, new_value); |
d82b3518 | 478 | } |
ed77134b | 479 | EXPORT_SYMBOL_GPL(pm_qos_update_request); |
d82b3518 | 480 | |
c4772d19 MH |
481 | /** |
482 | * pm_qos_update_request_timeout - modifies an existing qos request temporarily. | |
483 | * @req : handle to list element holding a pm_qos request to use | |
484 | * @new_value: defines the temporal qos request | |
485 | * @timeout_us: the effective duration of this qos request in usecs. | |
486 | * | |
487 | * After timeout_us, this qos request is cancelled automatically. | |
488 | */ | |
489 | void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, | |
490 | unsigned long timeout_us) | |
491 | { | |
492 | if (!req) | |
493 | return; | |
494 | if (WARN(!pm_qos_request_active(req), | |
495 | "%s called for unknown object.", __func__)) | |
496 | return; | |
497 | ||
ed1ac6e9 | 498 | cancel_delayed_work_sync(&req->work); |
c4772d19 | 499 | |
ae8822b8 S |
500 | trace_pm_qos_update_request_timeout(req->pm_qos_class, |
501 | new_value, timeout_us); | |
c4772d19 MH |
502 | if (new_value != req->node.prio) |
503 | pm_qos_update_target( | |
504 | pm_qos_array[req->pm_qos_class]->constraints, | |
505 | &req->node, PM_QOS_UPDATE_REQ, new_value); | |
506 | ||
507 | schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us)); | |
508 | } | |
509 | ||
d82b3518 | 510 | /** |
ed77134b | 511 | * pm_qos_remove_request - modifies an existing qos request |
cc749986 | 512 | * @req: handle to request list element |
d82b3518 | 513 | * |
cc749986 | 514 | * Will remove pm qos request from the list of constraints and |
ed77134b MG |
515 | * recompute the current target value for the pm_qos_class. Call this |
516 | * on slow code paths. | |
d82b3518 | 517 | */ |
cc749986 | 518 | void pm_qos_remove_request(struct pm_qos_request *req) |
d82b3518 | 519 | { |
abe98ec2 | 520 | if (!req) /*guard against callers passing in null */ |
ed77134b MG |
521 | return; |
522 | /* silent return to keep pcm code cleaner */ | |
d82b3518 | 523 | |
cc749986 | 524 | if (!pm_qos_request_active(req)) { |
82f68251 JB |
525 | WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n"); |
526 | return; | |
527 | } | |
528 | ||
ed1ac6e9 | 529 | cancel_delayed_work_sync(&req->work); |
c4772d19 | 530 | |
ae8822b8 | 531 | trace_pm_qos_remove_request(req->pm_qos_class, PM_QOS_DEFAULT_VALUE); |
abe98ec2 JP |
532 | pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, |
533 | &req->node, PM_QOS_REMOVE_REQ, | |
534 | PM_QOS_DEFAULT_VALUE); | |
cc749986 | 535 | memset(req, 0, sizeof(*req)); |
d82b3518 | 536 | } |
ed77134b | 537 | EXPORT_SYMBOL_GPL(pm_qos_remove_request); |
d82b3518 MG |
538 | |
539 | /** | |
540 | * pm_qos_add_notifier - sets notification entry for changes to target value | |
541 | * @pm_qos_class: identifies which qos target changes should be notified. | |
542 | * @notifier: notifier block managed by caller. | |
543 | * | |
544 | * will register the notifier into a notification chain that gets called | |
bf1db69f | 545 | * upon changes to the pm_qos_class target value. |
d82b3518 | 546 | */ |
ed77134b | 547 | int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) |
d82b3518 MG |
548 | { |
549 | int retval; | |
550 | ||
551 | retval = blocking_notifier_chain_register( | |
4e1779ba JP |
552 | pm_qos_array[pm_qos_class]->constraints->notifiers, |
553 | notifier); | |
d82b3518 MG |
554 | |
555 | return retval; | |
556 | } | |
557 | EXPORT_SYMBOL_GPL(pm_qos_add_notifier); | |
558 | ||
559 | /** | |
560 | * pm_qos_remove_notifier - deletes notification entry from chain. | |
561 | * @pm_qos_class: identifies which qos target changes are notified. | |
562 | * @notifier: notifier block to be removed. | |
563 | * | |
564 | * will remove the notifier from the notification chain that gets called | |
bf1db69f | 565 | * upon changes to the pm_qos_class target value. |
d82b3518 MG |
566 | */ |
567 | int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) | |
568 | { | |
569 | int retval; | |
570 | ||
571 | retval = blocking_notifier_chain_unregister( | |
4e1779ba JP |
572 | pm_qos_array[pm_qos_class]->constraints->notifiers, |
573 | notifier); | |
d82b3518 MG |
574 | |
575 | return retval; | |
576 | } | |
577 | EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); | |
578 | ||
4a31a334 | 579 | /* User space interface to PM QoS classes via misc devices */ |
f5f4eda4 | 580 | static int register_pm_qos_misc(struct pm_qos_object *qos, struct dentry *d) |
4a31a334 JP |
581 | { |
582 | qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR; | |
583 | qos->pm_qos_power_miscdev.name = qos->name; | |
584 | qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops; | |
585 | ||
659dc456 GKH |
586 | debugfs_create_file(qos->name, S_IRUGO, d, (void *)qos, |
587 | &pm_qos_debug_fops); | |
f5f4eda4 | 588 | |
4a31a334 JP |
589 | return misc_register(&qos->pm_qos_power_miscdev); |
590 | } | |
591 | ||
592 | static int find_pm_qos_object_by_minor(int minor) | |
593 | { | |
594 | int pm_qos_class; | |
595 | ||
d24c2a4f | 596 | for (pm_qos_class = PM_QOS_CPU_DMA_LATENCY; |
4a31a334 JP |
597 | pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) { |
598 | if (minor == | |
599 | pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor) | |
600 | return pm_qos_class; | |
601 | } | |
602 | return -1; | |
603 | } | |
604 | ||
d82b3518 MG |
605 | static int pm_qos_power_open(struct inode *inode, struct file *filp) |
606 | { | |
d82b3518 MG |
607 | long pm_qos_class; |
608 | ||
609 | pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); | |
d24c2a4f | 610 | if (pm_qos_class >= PM_QOS_CPU_DMA_LATENCY) { |
cc749986 | 611 | struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL); |
82f68251 JB |
612 | if (!req) |
613 | return -ENOMEM; | |
614 | ||
615 | pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE); | |
616 | filp->private_data = req; | |
ed77134b | 617 | |
6513fd69 | 618 | return 0; |
d82b3518 | 619 | } |
d82b3518 MG |
620 | return -EPERM; |
621 | } | |
622 | ||
623 | static int pm_qos_power_release(struct inode *inode, struct file *filp) | |
624 | { | |
cc749986 | 625 | struct pm_qos_request *req; |
d82b3518 | 626 | |
82f68251 | 627 | req = filp->private_data; |
ed77134b | 628 | pm_qos_remove_request(req); |
82f68251 | 629 | kfree(req); |
d82b3518 MG |
630 | |
631 | return 0; | |
632 | } | |
633 | ||
ed77134b | 634 | |
f9b9e806 TR |
635 | static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, |
636 | size_t count, loff_t *f_pos) | |
637 | { | |
638 | s32 value; | |
639 | unsigned long flags; | |
cc749986 | 640 | struct pm_qos_request *req = filp->private_data; |
f9b9e806 | 641 | |
cc749986 | 642 | if (!req) |
f9b9e806 | 643 | return -EINVAL; |
cc749986 | 644 | if (!pm_qos_request_active(req)) |
f9b9e806 TR |
645 | return -EINVAL; |
646 | ||
f9b9e806 | 647 | spin_lock_irqsave(&pm_qos_lock, flags); |
abe98ec2 | 648 | value = pm_qos_get_value(pm_qos_array[req->pm_qos_class]->constraints); |
f9b9e806 TR |
649 | spin_unlock_irqrestore(&pm_qos_lock, flags); |
650 | ||
651 | return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32)); | |
652 | } | |
653 | ||
d82b3518 MG |
654 | static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, |
655 | size_t count, loff_t *f_pos) | |
656 | { | |
657 | s32 value; | |
cc749986 | 658 | struct pm_qos_request *req; |
ed77134b MG |
659 | |
660 | if (count == sizeof(s32)) { | |
661 | if (copy_from_user(&value, buf, sizeof(s32))) | |
662 | return -EFAULT; | |
d4f7ecf7 | 663 | } else { |
0775a60a RW |
664 | int ret; |
665 | ||
d4f7ecf7 AS |
666 | ret = kstrtos32_from_user(buf, count, 16, &value); |
667 | if (ret) | |
668 | return ret; | |
0775a60a | 669 | } |
d82b3518 | 670 | |
cc749986 JP |
671 | req = filp->private_data; |
672 | pm_qos_update_request(req, value); | |
ed77134b MG |
673 | |
674 | return count; | |
d82b3518 MG |
675 | } |
676 | ||
677 | ||
678 | static int __init pm_qos_power_init(void) | |
679 | { | |
680 | int ret = 0; | |
d031e1de | 681 | int i; |
f5f4eda4 | 682 | struct dentry *d; |
d82b3518 | 683 | |
d031e1de AF |
684 | BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES); |
685 | ||
f5f4eda4 | 686 | d = debugfs_create_dir("pm_qos", NULL); |
f5f4eda4 | 687 | |
d24c2a4f | 688 | for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) { |
f5f4eda4 | 689 | ret = register_pm_qos_misc(pm_qos_array[i], d); |
d031e1de | 690 | if (ret < 0) { |
64ec72a1 JP |
691 | pr_err("%s: %s setup failed\n", |
692 | __func__, pm_qos_array[i]->name); | |
d031e1de AF |
693 | return ret; |
694 | } | |
d82b3518 | 695 | } |
d82b3518 MG |
696 | |
697 | return ret; | |
698 | } | |
699 | ||
700 | late_initcall(pm_qos_power_init); |