Commit | Line | Data |
---|---|---|
4f86d3a8 LB |
1 | /* |
2 | * cpuidle.c - core cpuidle infrastructure | |
3 | * | |
4 | * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | |
5 | * Shaohua Li <shaohua.li@intel.com> | |
6 | * Adam Belay <abelay@novell.com> | |
7 | * | |
8 | * This code is licenced under the GPL. | |
9 | */ | |
10 | ||
b60e6a0e | 11 | #include <linux/clockchips.h> |
4f86d3a8 LB |
12 | #include <linux/kernel.h> |
13 | #include <linux/mutex.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/notifier.h> | |
e8db0be1 | 16 | #include <linux/pm_qos.h> |
4f86d3a8 LB |
17 | #include <linux/cpu.h> |
18 | #include <linux/cpuidle.h> | |
9a0b8415 | 19 | #include <linux/ktime.h> |
2e94d1f7 | 20 | #include <linux/hrtimer.h> |
884b17e1 | 21 | #include <linux/module.h> |
38106313 | 22 | #include <linux/suspend.h> |
124cf911 | 23 | #include <linux/tick.h> |
288f023e | 24 | #include <trace/events/power.h> |
4f86d3a8 LB |
25 | |
26 | #include "cpuidle.h" | |
27 | ||
28 | DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices); | |
4c637b21 | 29 | DEFINE_PER_CPU(struct cpuidle_device, cpuidle_dev); |
4f86d3a8 LB |
30 | |
31 | DEFINE_MUTEX(cpuidle_lock); | |
32 | LIST_HEAD(cpuidle_detected_devices); | |
4f86d3a8 LB |
33 | |
34 | static int enabled_devices; | |
62027aea | 35 | static int off __read_mostly; |
a0bfa137 | 36 | static int initialized __read_mostly; |
62027aea LB |
37 | |
38 | int cpuidle_disabled(void) | |
39 | { | |
40 | return off; | |
41 | } | |
d91ee586 LB |
42 | void disable_cpuidle(void) |
43 | { | |
44 | off = 1; | |
45 | } | |
4f86d3a8 | 46 | |
ef2b22ac RW |
47 | bool cpuidle_not_available(struct cpuidle_driver *drv, |
48 | struct cpuidle_device *dev) | |
31a34090 RW |
49 | { |
50 | return off || !initialized || !drv || !dev || !dev->enabled; | |
51 | } | |
52 | ||
1a022e3f BO |
53 | /** |
54 | * cpuidle_play_dead - cpu off-lining | |
55 | * | |
ee01e663 | 56 | * Returns in case of an error or no driver |
1a022e3f BO |
57 | */ |
58 | int cpuidle_play_dead(void) | |
59 | { | |
60 | struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); | |
bf4d1b5d | 61 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
8aef33a7 | 62 | int i; |
1a022e3f | 63 | |
ee01e663 TK |
64 | if (!drv) |
65 | return -ENODEV; | |
66 | ||
1a022e3f | 67 | /* Find lowest-power state that supports long-term idle */ |
8aef33a7 DL |
68 | for (i = drv->state_count - 1; i >= CPUIDLE_DRIVER_STATE_START; i--) |
69 | if (drv->states[i].enter_dead) | |
70 | return drv->states[i].enter_dead(dev, i); | |
1a022e3f BO |
71 | |
72 | return -ENODEV; | |
73 | } | |
74 | ||
ef2b22ac RW |
75 | static int find_deepest_state(struct cpuidle_driver *drv, |
76 | struct cpuidle_device *dev, bool freeze) | |
a6220fc1 RW |
77 | { |
78 | unsigned int latency_req = 0; | |
124cf911 | 79 | int i, ret = freeze ? -1 : CPUIDLE_DRIVER_STATE_START - 1; |
a6220fc1 RW |
80 | |
81 | for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) { | |
82 | struct cpuidle_state *s = &drv->states[i]; | |
83 | struct cpuidle_state_usage *su = &dev->states_usage[i]; | |
84 | ||
124cf911 RW |
85 | if (s->disabled || su->disable || s->exit_latency <= latency_req |
86 | || (freeze && !s->enter_freeze)) | |
a6220fc1 RW |
87 | continue; |
88 | ||
89 | latency_req = s->exit_latency; | |
90 | ret = i; | |
91 | } | |
92 | return ret; | |
93 | } | |
94 | ||
ef2b22ac RW |
95 | /** |
96 | * cpuidle_find_deepest_state - Find the deepest available idle state. | |
97 | * @drv: cpuidle driver for the given CPU. | |
98 | * @dev: cpuidle device for the given CPU. | |
99 | */ | |
100 | int cpuidle_find_deepest_state(struct cpuidle_driver *drv, | |
101 | struct cpuidle_device *dev) | |
102 | { | |
103 | return find_deepest_state(drv, dev, false); | |
104 | } | |
105 | ||
124cf911 RW |
106 | static void enter_freeze_proper(struct cpuidle_driver *drv, |
107 | struct cpuidle_device *dev, int index) | |
108 | { | |
109 | tick_freeze(); | |
110 | /* | |
111 | * The state used here cannot be a "coupled" one, because the "coupled" | |
112 | * cpuidle mechanism enables interrupts and doing that with timekeeping | |
113 | * suspended is generally unsafe. | |
114 | */ | |
115 | drv->states[index].enter_freeze(dev, drv, index); | |
116 | WARN_ON(!irqs_disabled()); | |
117 | /* | |
118 | * timekeeping_resume() that will be called by tick_unfreeze() for the | |
119 | * last CPU executing it calls functions containing RCU read-side | |
120 | * critical sections, so tell RCU about that. | |
121 | */ | |
122 | RCU_NONIDLE(tick_unfreeze()); | |
123 | } | |
124 | ||
38106313 RW |
125 | /** |
126 | * cpuidle_enter_freeze - Enter an idle state suitable for suspend-to-idle. | |
ef2b22ac RW |
127 | * @drv: cpuidle driver for the given CPU. |
128 | * @dev: cpuidle device for the given CPU. | |
38106313 | 129 | * |
124cf911 | 130 | * If there are states with the ->enter_freeze callback, find the deepest of |
ef2b22ac | 131 | * them and enter it with frozen tick. |
38106313 | 132 | */ |
ef2b22ac | 133 | int cpuidle_enter_freeze(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
38106313 | 134 | { |
38106313 RW |
135 | int index; |
136 | ||
124cf911 RW |
137 | /* |
138 | * Find the deepest state with ->enter_freeze present, which guarantees | |
139 | * that interrupts won't be enabled when it exits and allows the tick to | |
140 | * be frozen safely. | |
141 | */ | |
ef2b22ac RW |
142 | index = find_deepest_state(drv, dev, true); |
143 | if (index >= 0) | |
124cf911 | 144 | enter_freeze_proper(drv, dev, index); |
124cf911 | 145 | |
ef2b22ac | 146 | return index; |
38106313 RW |
147 | } |
148 | ||
56cfbf74 CC |
149 | /** |
150 | * cpuidle_enter_state - enter the state and update stats | |
151 | * @dev: cpuidle device for this cpu | |
152 | * @drv: cpuidle driver for this cpu | |
153 | * @next_state: index into drv->states of the state to enter | |
154 | */ | |
155 | int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, | |
554c06ba | 156 | int index) |
56cfbf74 CC |
157 | { |
158 | int entered_state; | |
159 | ||
554c06ba DL |
160 | struct cpuidle_state *target_state = &drv->states[index]; |
161 | ktime_t time_start, time_end; | |
162 | s64 diff; | |
163 | ||
30fe6884 | 164 | trace_cpu_idle_rcuidle(index, dev->cpu); |
554c06ba DL |
165 | time_start = ktime_get(); |
166 | ||
167 | entered_state = target_state->enter(dev, drv, index); | |
168 | ||
169 | time_end = ktime_get(); | |
30fe6884 | 170 | trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); |
554c06ba | 171 | |
0b89e9aa PB |
172 | if (!cpuidle_state_is_coupled(dev, drv, entered_state)) |
173 | local_irq_enable(); | |
554c06ba DL |
174 | |
175 | diff = ktime_to_us(ktime_sub(time_end, time_start)); | |
176 | if (diff > INT_MAX) | |
177 | diff = INT_MAX; | |
178 | ||
179 | dev->last_residency = (int) diff; | |
56cfbf74 CC |
180 | |
181 | if (entered_state >= 0) { | |
182 | /* Update cpuidle counters */ | |
183 | /* This can be moved to within driver enter routine | |
184 | * but that results in multiple copies of same code. | |
185 | */ | |
a474a515 | 186 | dev->states_usage[entered_state].time += dev->last_residency; |
56cfbf74 CC |
187 | dev->states_usage[entered_state].usage++; |
188 | } else { | |
189 | dev->last_residency = 0; | |
190 | } | |
191 | ||
192 | return entered_state; | |
193 | } | |
194 | ||
4f86d3a8 | 195 | /** |
907e30f1 DL |
196 | * cpuidle_select - ask the cpuidle framework to choose an idle state |
197 | * | |
198 | * @drv: the cpuidle driver | |
199 | * @dev: the cpuidle device | |
4f86d3a8 | 200 | * |
907e30f1 | 201 | * Returns the index of the idle state. |
4f86d3a8 | 202 | */ |
907e30f1 | 203 | int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
4f86d3a8 | 204 | { |
907e30f1 DL |
205 | return cpuidle_curr_governor->select(drv, dev); |
206 | } | |
ba8f20c2 | 207 | |
907e30f1 DL |
208 | /** |
209 | * cpuidle_enter - enter into the specified idle state | |
210 | * | |
211 | * @drv: the cpuidle driver tied with the cpu | |
212 | * @dev: the cpuidle device | |
213 | * @index: the index in the idle state table | |
214 | * | |
215 | * Returns the index in the idle state, < 0 in case of error. | |
216 | * The error code depends on the backend driver | |
217 | */ | |
218 | int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, | |
219 | int index) | |
220 | { | |
221 | if (cpuidle_state_is_coupled(dev, drv, index)) | |
222 | return cpuidle_enter_state_coupled(dev, drv, index); | |
223 | return cpuidle_enter_state(dev, drv, index); | |
224 | } | |
b60e6a0e | 225 | |
907e30f1 DL |
226 | /** |
227 | * cpuidle_reflect - tell the underlying governor what was the state | |
228 | * we were in | |
229 | * | |
230 | * @dev : the cpuidle device | |
231 | * @index: the index in the idle state table | |
232 | * | |
233 | */ | |
234 | void cpuidle_reflect(struct cpuidle_device *dev, int index) | |
235 | { | |
38106313 | 236 | if (cpuidle_curr_governor->reflect) |
907e30f1 | 237 | cpuidle_curr_governor->reflect(dev, index); |
4f86d3a8 LB |
238 | } |
239 | ||
240 | /** | |
241 | * cpuidle_install_idle_handler - installs the cpuidle idle loop handler | |
242 | */ | |
243 | void cpuidle_install_idle_handler(void) | |
244 | { | |
a0bfa137 | 245 | if (enabled_devices) { |
4f86d3a8 LB |
246 | /* Make sure all changes finished before we switch to new idle */ |
247 | smp_wmb(); | |
a0bfa137 | 248 | initialized = 1; |
4f86d3a8 LB |
249 | } |
250 | } | |
251 | ||
252 | /** | |
253 | * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler | |
254 | */ | |
255 | void cpuidle_uninstall_idle_handler(void) | |
256 | { | |
a0bfa137 LB |
257 | if (enabled_devices) { |
258 | initialized = 0; | |
2ed903c5 | 259 | wake_up_all_idle_cpus(); |
4f86d3a8 | 260 | } |
442bf3aa DL |
261 | |
262 | /* | |
263 | * Make sure external observers (such as the scheduler) | |
264 | * are done looking at pointed idle states. | |
265 | */ | |
266 | synchronize_rcu(); | |
4f86d3a8 LB |
267 | } |
268 | ||
269 | /** | |
270 | * cpuidle_pause_and_lock - temporarily disables CPUIDLE | |
271 | */ | |
272 | void cpuidle_pause_and_lock(void) | |
273 | { | |
274 | mutex_lock(&cpuidle_lock); | |
275 | cpuidle_uninstall_idle_handler(); | |
276 | } | |
277 | ||
278 | EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock); | |
279 | ||
280 | /** | |
281 | * cpuidle_resume_and_unlock - resumes CPUIDLE operation | |
282 | */ | |
283 | void cpuidle_resume_and_unlock(void) | |
284 | { | |
285 | cpuidle_install_idle_handler(); | |
286 | mutex_unlock(&cpuidle_lock); | |
287 | } | |
288 | ||
289 | EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); | |
290 | ||
8651f97b PM |
291 | /* Currently used in suspend/resume path to suspend cpuidle */ |
292 | void cpuidle_pause(void) | |
293 | { | |
294 | mutex_lock(&cpuidle_lock); | |
295 | cpuidle_uninstall_idle_handler(); | |
296 | mutex_unlock(&cpuidle_lock); | |
297 | } | |
298 | ||
299 | /* Currently used in suspend/resume path to resume cpuidle */ | |
300 | void cpuidle_resume(void) | |
301 | { | |
302 | mutex_lock(&cpuidle_lock); | |
303 | cpuidle_install_idle_handler(); | |
304 | mutex_unlock(&cpuidle_lock); | |
305 | } | |
306 | ||
4f86d3a8 LB |
307 | /** |
308 | * cpuidle_enable_device - enables idle PM for a CPU | |
309 | * @dev: the CPU | |
310 | * | |
311 | * This function must be called between cpuidle_pause_and_lock and | |
312 | * cpuidle_resume_and_unlock when used externally. | |
313 | */ | |
314 | int cpuidle_enable_device(struct cpuidle_device *dev) | |
315 | { | |
5df0aa73 | 316 | int ret; |
bf4d1b5d | 317 | struct cpuidle_driver *drv; |
4f86d3a8 | 318 | |
1b0a0e9a SB |
319 | if (!dev) |
320 | return -EINVAL; | |
321 | ||
4f86d3a8 LB |
322 | if (dev->enabled) |
323 | return 0; | |
bf4d1b5d DL |
324 | |
325 | drv = cpuidle_get_cpu_driver(dev); | |
326 | ||
e1689795 | 327 | if (!drv || !cpuidle_curr_governor) |
4f86d3a8 | 328 | return -EIO; |
bf4d1b5d | 329 | |
10b9d3f8 DL |
330 | if (!dev->registered) |
331 | return -EINVAL; | |
332 | ||
bf4d1b5d DL |
333 | ret = cpuidle_add_device_sysfs(dev); |
334 | if (ret) | |
4f86d3a8 LB |
335 | return ret; |
336 | ||
337 | if (cpuidle_curr_governor->enable && | |
e1689795 | 338 | (ret = cpuidle_curr_governor->enable(drv, dev))) |
4f86d3a8 LB |
339 | goto fail_sysfs; |
340 | ||
4f86d3a8 LB |
341 | smp_wmb(); |
342 | ||
343 | dev->enabled = 1; | |
344 | ||
345 | enabled_devices++; | |
346 | return 0; | |
347 | ||
348 | fail_sysfs: | |
bf4d1b5d | 349 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
350 | |
351 | return ret; | |
352 | } | |
353 | ||
354 | EXPORT_SYMBOL_GPL(cpuidle_enable_device); | |
355 | ||
356 | /** | |
357 | * cpuidle_disable_device - disables idle PM for a CPU | |
358 | * @dev: the CPU | |
359 | * | |
360 | * This function must be called between cpuidle_pause_and_lock and | |
361 | * cpuidle_resume_and_unlock when used externally. | |
362 | */ | |
363 | void cpuidle_disable_device(struct cpuidle_device *dev) | |
364 | { | |
bf4d1b5d DL |
365 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
366 | ||
cf31cd1a | 367 | if (!dev || !dev->enabled) |
4f86d3a8 | 368 | return; |
bf4d1b5d DL |
369 | |
370 | if (!drv || !cpuidle_curr_governor) | |
4f86d3a8 LB |
371 | return; |
372 | ||
373 | dev->enabled = 0; | |
374 | ||
375 | if (cpuidle_curr_governor->disable) | |
bf4d1b5d | 376 | cpuidle_curr_governor->disable(drv, dev); |
4f86d3a8 | 377 | |
bf4d1b5d | 378 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
379 | enabled_devices--; |
380 | } | |
381 | ||
382 | EXPORT_SYMBOL_GPL(cpuidle_disable_device); | |
383 | ||
f6bb51a5 DL |
384 | static void __cpuidle_unregister_device(struct cpuidle_device *dev) |
385 | { | |
386 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); | |
387 | ||
388 | list_del(&dev->device_list); | |
389 | per_cpu(cpuidle_devices, dev->cpu) = NULL; | |
390 | module_put(drv->owner); | |
391 | } | |
392 | ||
267d4bf8 | 393 | static void __cpuidle_device_init(struct cpuidle_device *dev) |
5df0aa73 DL |
394 | { |
395 | memset(dev->states_usage, 0, sizeof(dev->states_usage)); | |
396 | dev->last_residency = 0; | |
5df0aa73 DL |
397 | } |
398 | ||
4f86d3a8 | 399 | /** |
dcb84f33 VP |
400 | * __cpuidle_register_device - internal register function called before register |
401 | * and enable routines | |
4f86d3a8 | 402 | * @dev: the cpu |
dcb84f33 VP |
403 | * |
404 | * cpuidle_lock mutex must be held before this is called | |
4f86d3a8 | 405 | */ |
dcb84f33 | 406 | static int __cpuidle_register_device(struct cpuidle_device *dev) |
4f86d3a8 LB |
407 | { |
408 | int ret; | |
bf4d1b5d | 409 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
4f86d3a8 | 410 | |
bf4d1b5d | 411 | if (!try_module_get(drv->owner)) |
4f86d3a8 LB |
412 | return -EINVAL; |
413 | ||
4f86d3a8 LB |
414 | per_cpu(cpuidle_devices, dev->cpu) = dev; |
415 | list_add(&dev->device_list, &cpuidle_detected_devices); | |
4f86d3a8 | 416 | |
4126c019 | 417 | ret = cpuidle_coupled_register_device(dev); |
47182668 | 418 | if (ret) |
f6bb51a5 | 419 | __cpuidle_unregister_device(dev); |
47182668 VK |
420 | else |
421 | dev->registered = 1; | |
4f86d3a8 | 422 | |
47182668 | 423 | return ret; |
dcb84f33 VP |
424 | } |
425 | ||
426 | /** | |
427 | * cpuidle_register_device - registers a CPU's idle PM feature | |
428 | * @dev: the cpu | |
429 | */ | |
430 | int cpuidle_register_device(struct cpuidle_device *dev) | |
431 | { | |
c878a52d | 432 | int ret = -EBUSY; |
dcb84f33 | 433 | |
1b0a0e9a SB |
434 | if (!dev) |
435 | return -EINVAL; | |
436 | ||
dcb84f33 VP |
437 | mutex_lock(&cpuidle_lock); |
438 | ||
c878a52d DL |
439 | if (dev->registered) |
440 | goto out_unlock; | |
441 | ||
267d4bf8 | 442 | __cpuidle_device_init(dev); |
5df0aa73 | 443 | |
f6bb51a5 DL |
444 | ret = __cpuidle_register_device(dev); |
445 | if (ret) | |
446 | goto out_unlock; | |
447 | ||
448 | ret = cpuidle_add_sysfs(dev); | |
449 | if (ret) | |
450 | goto out_unregister; | |
dcb84f33 | 451 | |
10b9d3f8 | 452 | ret = cpuidle_enable_device(dev); |
f6bb51a5 DL |
453 | if (ret) |
454 | goto out_sysfs; | |
10b9d3f8 | 455 | |
4f86d3a8 LB |
456 | cpuidle_install_idle_handler(); |
457 | ||
f6bb51a5 | 458 | out_unlock: |
4f86d3a8 LB |
459 | mutex_unlock(&cpuidle_lock); |
460 | ||
f6bb51a5 DL |
461 | return ret; |
462 | ||
463 | out_sysfs: | |
464 | cpuidle_remove_sysfs(dev); | |
465 | out_unregister: | |
466 | __cpuidle_unregister_device(dev); | |
467 | goto out_unlock; | |
4f86d3a8 LB |
468 | } |
469 | ||
470 | EXPORT_SYMBOL_GPL(cpuidle_register_device); | |
471 | ||
472 | /** | |
473 | * cpuidle_unregister_device - unregisters a CPU's idle PM feature | |
474 | * @dev: the cpu | |
475 | */ | |
476 | void cpuidle_unregister_device(struct cpuidle_device *dev) | |
477 | { | |
813e8e3d | 478 | if (!dev || dev->registered == 0) |
dcb84f33 VP |
479 | return; |
480 | ||
4f86d3a8 LB |
481 | cpuidle_pause_and_lock(); |
482 | ||
483 | cpuidle_disable_device(dev); | |
484 | ||
1aef40e2 | 485 | cpuidle_remove_sysfs(dev); |
f6bb51a5 DL |
486 | |
487 | __cpuidle_unregister_device(dev); | |
4f86d3a8 | 488 | |
4126c019 CC |
489 | cpuidle_coupled_unregister_device(dev); |
490 | ||
4f86d3a8 | 491 | cpuidle_resume_and_unlock(); |
4f86d3a8 LB |
492 | } |
493 | ||
494 | EXPORT_SYMBOL_GPL(cpuidle_unregister_device); | |
495 | ||
1c192d04 | 496 | /** |
4c637b21 DL |
497 | * cpuidle_unregister: unregister a driver and the devices. This function |
498 | * can be used only if the driver has been previously registered through | |
499 | * the cpuidle_register function. | |
500 | * | |
501 | * @drv: a valid pointer to a struct cpuidle_driver | |
502 | */ | |
503 | void cpuidle_unregister(struct cpuidle_driver *drv) | |
504 | { | |
505 | int cpu; | |
506 | struct cpuidle_device *device; | |
507 | ||
82467a5a | 508 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
509 | device = &per_cpu(cpuidle_dev, cpu); |
510 | cpuidle_unregister_device(device); | |
511 | } | |
512 | ||
513 | cpuidle_unregister_driver(drv); | |
514 | } | |
515 | EXPORT_SYMBOL_GPL(cpuidle_unregister); | |
516 | ||
517 | /** | |
518 | * cpuidle_register: registers the driver and the cpu devices with the | |
519 | * coupled_cpus passed as parameter. This function is used for all common | |
520 | * initialization pattern there are in the arch specific drivers. The | |
521 | * devices is globally defined in this file. | |
522 | * | |
523 | * @drv : a valid pointer to a struct cpuidle_driver | |
524 | * @coupled_cpus: a cpumask for the coupled states | |
525 | * | |
526 | * Returns 0 on success, < 0 otherwise | |
527 | */ | |
528 | int cpuidle_register(struct cpuidle_driver *drv, | |
529 | const struct cpumask *const coupled_cpus) | |
530 | { | |
531 | int ret, cpu; | |
532 | struct cpuidle_device *device; | |
533 | ||
534 | ret = cpuidle_register_driver(drv); | |
535 | if (ret) { | |
536 | pr_err("failed to register cpuidle driver\n"); | |
537 | return ret; | |
538 | } | |
539 | ||
82467a5a | 540 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
541 | device = &per_cpu(cpuidle_dev, cpu); |
542 | device->cpu = cpu; | |
543 | ||
544 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED | |
545 | /* | |
caf4a36e | 546 | * On multiplatform for ARM, the coupled idle states could be |
4c637b21 DL |
547 | * enabled in the kernel even if the cpuidle driver does not |
548 | * use it. Note, coupled_cpus is a struct copy. | |
549 | */ | |
550 | if (coupled_cpus) | |
551 | device->coupled_cpus = *coupled_cpus; | |
552 | #endif | |
553 | ret = cpuidle_register_device(device); | |
554 | if (!ret) | |
555 | continue; | |
556 | ||
557 | pr_err("Failed to register cpuidle device for cpu%d\n", cpu); | |
558 | ||
559 | cpuidle_unregister(drv); | |
560 | break; | |
561 | } | |
562 | ||
563 | return ret; | |
564 | } | |
565 | EXPORT_SYMBOL_GPL(cpuidle_register); | |
566 | ||
4f86d3a8 LB |
567 | #ifdef CONFIG_SMP |
568 | ||
4f86d3a8 LB |
569 | /* |
570 | * This function gets called when a part of the kernel has a new latency | |
571 | * requirement. This means we need to get all processors out of their C-state, | |
572 | * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that | |
573 | * wakes them all right up. | |
574 | */ | |
575 | static int cpuidle_latency_notify(struct notifier_block *b, | |
576 | unsigned long l, void *v) | |
577 | { | |
2ed903c5 | 578 | wake_up_all_idle_cpus(); |
4f86d3a8 LB |
579 | return NOTIFY_OK; |
580 | } | |
581 | ||
582 | static struct notifier_block cpuidle_latency_notifier = { | |
583 | .notifier_call = cpuidle_latency_notify, | |
584 | }; | |
585 | ||
d82b3518 MG |
586 | static inline void latency_notifier_init(struct notifier_block *n) |
587 | { | |
588 | pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n); | |
589 | } | |
4f86d3a8 LB |
590 | |
591 | #else /* CONFIG_SMP */ | |
592 | ||
593 | #define latency_notifier_init(x) do { } while (0) | |
594 | ||
595 | #endif /* CONFIG_SMP */ | |
596 | ||
597 | /** | |
598 | * cpuidle_init - core initializer | |
599 | */ | |
600 | static int __init cpuidle_init(void) | |
601 | { | |
602 | int ret; | |
603 | ||
62027aea LB |
604 | if (cpuidle_disabled()) |
605 | return -ENODEV; | |
606 | ||
8a25a2fd | 607 | ret = cpuidle_add_interface(cpu_subsys.dev_root); |
4f86d3a8 LB |
608 | if (ret) |
609 | return ret; | |
610 | ||
611 | latency_notifier_init(&cpuidle_latency_notifier); | |
612 | ||
613 | return 0; | |
614 | } | |
615 | ||
62027aea | 616 | module_param(off, int, 0444); |
4f86d3a8 | 617 | core_initcall(cpuidle_init); |