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 */ |
7d51d979 | 68 | for (i = drv->state_count - 1; i >= 0; i--) |
8aef33a7 DL |
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 | 75 | static int find_deepest_state(struct cpuidle_driver *drv, |
0d94039f RW |
76 | struct cpuidle_device *dev, |
77 | unsigned int max_latency, | |
78 | unsigned int forbidden_flags, | |
79 | bool freeze) | |
a6220fc1 RW |
80 | { |
81 | unsigned int latency_req = 0; | |
51164251 | 82 | int i, ret = 0; |
a6220fc1 | 83 | |
51164251 | 84 | for (i = 1; i < drv->state_count; i++) { |
a6220fc1 RW |
85 | struct cpuidle_state *s = &drv->states[i]; |
86 | struct cpuidle_state_usage *su = &dev->states_usage[i]; | |
87 | ||
124cf911 | 88 | if (s->disabled || su->disable || s->exit_latency <= latency_req |
0d94039f RW |
89 | || s->exit_latency > max_latency |
90 | || (s->flags & forbidden_flags) | |
124cf911 | 91 | || (freeze && !s->enter_freeze)) |
a6220fc1 RW |
92 | continue; |
93 | ||
94 | latency_req = s->exit_latency; | |
95 | ret = i; | |
96 | } | |
97 | return ret; | |
98 | } | |
99 | ||
87e9b9f1 | 100 | #ifdef CONFIG_SUSPEND |
ef2b22ac RW |
101 | /** |
102 | * cpuidle_find_deepest_state - Find the deepest available idle state. | |
103 | * @drv: cpuidle driver for the given CPU. | |
104 | * @dev: cpuidle device for the given CPU. | |
105 | */ | |
106 | int cpuidle_find_deepest_state(struct cpuidle_driver *drv, | |
107 | struct cpuidle_device *dev) | |
108 | { | |
0d94039f | 109 | return find_deepest_state(drv, dev, UINT_MAX, 0, false); |
ef2b22ac RW |
110 | } |
111 | ||
124cf911 RW |
112 | static void enter_freeze_proper(struct cpuidle_driver *drv, |
113 | struct cpuidle_device *dev, int index) | |
114 | { | |
ae0afb4f RW |
115 | /* |
116 | * trace_suspend_resume() called by tick_freeze() for the last CPU | |
117 | * executing it contains RCU usage regarded as invalid in the idle | |
118 | * context, so tell RCU about that. | |
119 | */ | |
120 | RCU_NONIDLE(tick_freeze()); | |
124cf911 RW |
121 | /* |
122 | * The state used here cannot be a "coupled" one, because the "coupled" | |
123 | * cpuidle mechanism enables interrupts and doing that with timekeeping | |
124 | * suspended is generally unsafe. | |
125 | */ | |
63caae84 | 126 | stop_critical_timings(); |
124cf911 RW |
127 | drv->states[index].enter_freeze(dev, drv, index); |
128 | WARN_ON(!irqs_disabled()); | |
129 | /* | |
130 | * timekeeping_resume() that will be called by tick_unfreeze() for the | |
ae0afb4f | 131 | * first CPU executing it calls functions containing RCU read-side |
124cf911 RW |
132 | * critical sections, so tell RCU about that. |
133 | */ | |
134 | RCU_NONIDLE(tick_unfreeze()); | |
63caae84 | 135 | start_critical_timings(); |
124cf911 RW |
136 | } |
137 | ||
38106313 RW |
138 | /** |
139 | * cpuidle_enter_freeze - Enter an idle state suitable for suspend-to-idle. | |
ef2b22ac RW |
140 | * @drv: cpuidle driver for the given CPU. |
141 | * @dev: cpuidle device for the given CPU. | |
38106313 | 142 | * |
124cf911 | 143 | * If there are states with the ->enter_freeze callback, find the deepest of |
ef2b22ac | 144 | * them and enter it with frozen tick. |
38106313 | 145 | */ |
ef2b22ac | 146 | int cpuidle_enter_freeze(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
38106313 | 147 | { |
38106313 RW |
148 | int index; |
149 | ||
124cf911 RW |
150 | /* |
151 | * Find the deepest state with ->enter_freeze present, which guarantees | |
152 | * that interrupts won't be enabled when it exits and allows the tick to | |
153 | * be frozen safely. | |
154 | */ | |
0d94039f | 155 | index = find_deepest_state(drv, dev, UINT_MAX, 0, true); |
6f16886b | 156 | if (index > 0) |
124cf911 | 157 | enter_freeze_proper(drv, dev, index); |
124cf911 | 158 | |
ef2b22ac | 159 | return index; |
38106313 | 160 | } |
87e9b9f1 | 161 | #endif /* CONFIG_SUSPEND */ |
38106313 | 162 | |
56cfbf74 CC |
163 | /** |
164 | * cpuidle_enter_state - enter the state and update stats | |
165 | * @dev: cpuidle device for this cpu | |
166 | * @drv: cpuidle driver for this cpu | |
7312280b | 167 | * @index: index into the states table in @drv of the state to enter |
56cfbf74 CC |
168 | */ |
169 | int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, | |
554c06ba | 170 | int index) |
56cfbf74 CC |
171 | { |
172 | int entered_state; | |
173 | ||
554c06ba | 174 | struct cpuidle_state *target_state = &drv->states[index]; |
df8d9eea | 175 | bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP); |
554c06ba DL |
176 | ktime_t time_start, time_end; |
177 | s64 diff; | |
178 | ||
df8d9eea RW |
179 | /* |
180 | * Tell the time framework to switch to a broadcast timer because our | |
181 | * local timer will be shut down. If a local timer is used from another | |
182 | * CPU as a broadcast timer, this call may fail if it is not available. | |
183 | */ | |
827a5aef | 184 | if (broadcast && tick_broadcast_enter()) { |
0d94039f RW |
185 | index = find_deepest_state(drv, dev, target_state->exit_latency, |
186 | CPUIDLE_FLAG_TIMER_STOP, false); | |
187 | if (index < 0) { | |
188 | default_idle_call(); | |
189 | return -EBUSY; | |
190 | } | |
191 | target_state = &drv->states[index]; | |
827a5aef | 192 | } |
df8d9eea | 193 | |
faad3849 RW |
194 | /* Take note of the planned idle state. */ |
195 | sched_idle_set_state(target_state); | |
196 | ||
30fe6884 | 197 | trace_cpu_idle_rcuidle(index, dev->cpu); |
554c06ba DL |
198 | time_start = ktime_get(); |
199 | ||
63caae84 | 200 | stop_critical_timings(); |
554c06ba | 201 | entered_state = target_state->enter(dev, drv, index); |
63caae84 | 202 | start_critical_timings(); |
554c06ba DL |
203 | |
204 | time_end = ktime_get(); | |
30fe6884 | 205 | trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); |
554c06ba | 206 | |
faad3849 RW |
207 | /* The cpu is no longer idle or about to enter idle. */ |
208 | sched_idle_set_state(NULL); | |
209 | ||
df8d9eea RW |
210 | if (broadcast) { |
211 | if (WARN_ON_ONCE(!irqs_disabled())) | |
212 | local_irq_disable(); | |
213 | ||
214 | tick_broadcast_exit(); | |
215 | } | |
216 | ||
4c1ed5a6 | 217 | if (!cpuidle_state_is_coupled(drv, entered_state)) |
0b89e9aa | 218 | local_irq_enable(); |
554c06ba DL |
219 | |
220 | diff = ktime_to_us(ktime_sub(time_end, time_start)); | |
221 | if (diff > INT_MAX) | |
222 | diff = INT_MAX; | |
223 | ||
224 | dev->last_residency = (int) diff; | |
56cfbf74 CC |
225 | |
226 | if (entered_state >= 0) { | |
227 | /* Update cpuidle counters */ | |
228 | /* This can be moved to within driver enter routine | |
229 | * but that results in multiple copies of same code. | |
230 | */ | |
a474a515 | 231 | dev->states_usage[entered_state].time += dev->last_residency; |
56cfbf74 CC |
232 | dev->states_usage[entered_state].usage++; |
233 | } else { | |
234 | dev->last_residency = 0; | |
235 | } | |
236 | ||
237 | return entered_state; | |
238 | } | |
239 | ||
4f86d3a8 | 240 | /** |
907e30f1 DL |
241 | * cpuidle_select - ask the cpuidle framework to choose an idle state |
242 | * | |
243 | * @drv: the cpuidle driver | |
244 | * @dev: the cpuidle device | |
4f86d3a8 | 245 | * |
51164251 | 246 | * Returns the index of the idle state. The return value must not be negative. |
4f86d3a8 | 247 | */ |
907e30f1 | 248 | int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
4f86d3a8 | 249 | { |
907e30f1 DL |
250 | return cpuidle_curr_governor->select(drv, dev); |
251 | } | |
ba8f20c2 | 252 | |
907e30f1 DL |
253 | /** |
254 | * cpuidle_enter - enter into the specified idle state | |
255 | * | |
256 | * @drv: the cpuidle driver tied with the cpu | |
257 | * @dev: the cpuidle device | |
258 | * @index: the index in the idle state table | |
259 | * | |
260 | * Returns the index in the idle state, < 0 in case of error. | |
261 | * The error code depends on the backend driver | |
262 | */ | |
263 | int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, | |
264 | int index) | |
265 | { | |
4c1ed5a6 | 266 | if (cpuidle_state_is_coupled(drv, index)) |
907e30f1 DL |
267 | return cpuidle_enter_state_coupled(dev, drv, index); |
268 | return cpuidle_enter_state(dev, drv, index); | |
269 | } | |
b60e6a0e | 270 | |
907e30f1 DL |
271 | /** |
272 | * cpuidle_reflect - tell the underlying governor what was the state | |
273 | * we were in | |
274 | * | |
275 | * @dev : the cpuidle device | |
276 | * @index: the index in the idle state table | |
277 | * | |
278 | */ | |
279 | void cpuidle_reflect(struct cpuidle_device *dev, int index) | |
280 | { | |
a802ea96 | 281 | if (cpuidle_curr_governor->reflect && index >= 0) |
907e30f1 | 282 | cpuidle_curr_governor->reflect(dev, index); |
4f86d3a8 LB |
283 | } |
284 | ||
285 | /** | |
286 | * cpuidle_install_idle_handler - installs the cpuidle idle loop handler | |
287 | */ | |
288 | void cpuidle_install_idle_handler(void) | |
289 | { | |
a0bfa137 | 290 | if (enabled_devices) { |
4f86d3a8 LB |
291 | /* Make sure all changes finished before we switch to new idle */ |
292 | smp_wmb(); | |
a0bfa137 | 293 | initialized = 1; |
4f86d3a8 LB |
294 | } |
295 | } | |
296 | ||
297 | /** | |
298 | * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler | |
299 | */ | |
300 | void cpuidle_uninstall_idle_handler(void) | |
301 | { | |
a0bfa137 LB |
302 | if (enabled_devices) { |
303 | initialized = 0; | |
2ed903c5 | 304 | wake_up_all_idle_cpus(); |
4f86d3a8 | 305 | } |
442bf3aa DL |
306 | |
307 | /* | |
308 | * Make sure external observers (such as the scheduler) | |
309 | * are done looking at pointed idle states. | |
310 | */ | |
311 | synchronize_rcu(); | |
4f86d3a8 LB |
312 | } |
313 | ||
314 | /** | |
315 | * cpuidle_pause_and_lock - temporarily disables CPUIDLE | |
316 | */ | |
317 | void cpuidle_pause_and_lock(void) | |
318 | { | |
319 | mutex_lock(&cpuidle_lock); | |
320 | cpuidle_uninstall_idle_handler(); | |
321 | } | |
322 | ||
323 | EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock); | |
324 | ||
325 | /** | |
326 | * cpuidle_resume_and_unlock - resumes CPUIDLE operation | |
327 | */ | |
328 | void cpuidle_resume_and_unlock(void) | |
329 | { | |
330 | cpuidle_install_idle_handler(); | |
331 | mutex_unlock(&cpuidle_lock); | |
332 | } | |
333 | ||
334 | EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); | |
335 | ||
8651f97b PM |
336 | /* Currently used in suspend/resume path to suspend cpuidle */ |
337 | void cpuidle_pause(void) | |
338 | { | |
339 | mutex_lock(&cpuidle_lock); | |
340 | cpuidle_uninstall_idle_handler(); | |
341 | mutex_unlock(&cpuidle_lock); | |
342 | } | |
343 | ||
344 | /* Currently used in suspend/resume path to resume cpuidle */ | |
345 | void cpuidle_resume(void) | |
346 | { | |
347 | mutex_lock(&cpuidle_lock); | |
348 | cpuidle_install_idle_handler(); | |
349 | mutex_unlock(&cpuidle_lock); | |
350 | } | |
351 | ||
4f86d3a8 LB |
352 | /** |
353 | * cpuidle_enable_device - enables idle PM for a CPU | |
354 | * @dev: the CPU | |
355 | * | |
356 | * This function must be called between cpuidle_pause_and_lock and | |
357 | * cpuidle_resume_and_unlock when used externally. | |
358 | */ | |
359 | int cpuidle_enable_device(struct cpuidle_device *dev) | |
360 | { | |
5df0aa73 | 361 | int ret; |
bf4d1b5d | 362 | struct cpuidle_driver *drv; |
4f86d3a8 | 363 | |
1b0a0e9a SB |
364 | if (!dev) |
365 | return -EINVAL; | |
366 | ||
4f86d3a8 LB |
367 | if (dev->enabled) |
368 | return 0; | |
bf4d1b5d DL |
369 | |
370 | drv = cpuidle_get_cpu_driver(dev); | |
371 | ||
e1689795 | 372 | if (!drv || !cpuidle_curr_governor) |
4f86d3a8 | 373 | return -EIO; |
bf4d1b5d | 374 | |
10b9d3f8 DL |
375 | if (!dev->registered) |
376 | return -EINVAL; | |
377 | ||
bf4d1b5d DL |
378 | ret = cpuidle_add_device_sysfs(dev); |
379 | if (ret) | |
4f86d3a8 LB |
380 | return ret; |
381 | ||
382 | if (cpuidle_curr_governor->enable && | |
e1689795 | 383 | (ret = cpuidle_curr_governor->enable(drv, dev))) |
4f86d3a8 LB |
384 | goto fail_sysfs; |
385 | ||
4f86d3a8 LB |
386 | smp_wmb(); |
387 | ||
388 | dev->enabled = 1; | |
389 | ||
390 | enabled_devices++; | |
391 | return 0; | |
392 | ||
393 | fail_sysfs: | |
bf4d1b5d | 394 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
395 | |
396 | return ret; | |
397 | } | |
398 | ||
399 | EXPORT_SYMBOL_GPL(cpuidle_enable_device); | |
400 | ||
401 | /** | |
402 | * cpuidle_disable_device - disables idle PM for a CPU | |
403 | * @dev: the CPU | |
404 | * | |
405 | * This function must be called between cpuidle_pause_and_lock and | |
406 | * cpuidle_resume_and_unlock when used externally. | |
407 | */ | |
408 | void cpuidle_disable_device(struct cpuidle_device *dev) | |
409 | { | |
bf4d1b5d DL |
410 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
411 | ||
cf31cd1a | 412 | if (!dev || !dev->enabled) |
4f86d3a8 | 413 | return; |
bf4d1b5d DL |
414 | |
415 | if (!drv || !cpuidle_curr_governor) | |
4f86d3a8 LB |
416 | return; |
417 | ||
418 | dev->enabled = 0; | |
419 | ||
420 | if (cpuidle_curr_governor->disable) | |
bf4d1b5d | 421 | cpuidle_curr_governor->disable(drv, dev); |
4f86d3a8 | 422 | |
bf4d1b5d | 423 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
424 | enabled_devices--; |
425 | } | |
426 | ||
427 | EXPORT_SYMBOL_GPL(cpuidle_disable_device); | |
428 | ||
f6bb51a5 DL |
429 | static void __cpuidle_unregister_device(struct cpuidle_device *dev) |
430 | { | |
431 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); | |
432 | ||
433 | list_del(&dev->device_list); | |
434 | per_cpu(cpuidle_devices, dev->cpu) = NULL; | |
435 | module_put(drv->owner); | |
436 | } | |
437 | ||
267d4bf8 | 438 | static void __cpuidle_device_init(struct cpuidle_device *dev) |
5df0aa73 DL |
439 | { |
440 | memset(dev->states_usage, 0, sizeof(dev->states_usage)); | |
441 | dev->last_residency = 0; | |
5df0aa73 DL |
442 | } |
443 | ||
4f86d3a8 | 444 | /** |
dcb84f33 VP |
445 | * __cpuidle_register_device - internal register function called before register |
446 | * and enable routines | |
4f86d3a8 | 447 | * @dev: the cpu |
dcb84f33 VP |
448 | * |
449 | * cpuidle_lock mutex must be held before this is called | |
4f86d3a8 | 450 | */ |
dcb84f33 | 451 | static int __cpuidle_register_device(struct cpuidle_device *dev) |
4f86d3a8 LB |
452 | { |
453 | int ret; | |
bf4d1b5d | 454 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
4f86d3a8 | 455 | |
bf4d1b5d | 456 | if (!try_module_get(drv->owner)) |
4f86d3a8 LB |
457 | return -EINVAL; |
458 | ||
4f86d3a8 LB |
459 | per_cpu(cpuidle_devices, dev->cpu) = dev; |
460 | list_add(&dev->device_list, &cpuidle_detected_devices); | |
4f86d3a8 | 461 | |
4126c019 | 462 | ret = cpuidle_coupled_register_device(dev); |
47182668 | 463 | if (ret) |
f6bb51a5 | 464 | __cpuidle_unregister_device(dev); |
47182668 VK |
465 | else |
466 | dev->registered = 1; | |
4f86d3a8 | 467 | |
47182668 | 468 | return ret; |
dcb84f33 VP |
469 | } |
470 | ||
471 | /** | |
472 | * cpuidle_register_device - registers a CPU's idle PM feature | |
473 | * @dev: the cpu | |
474 | */ | |
475 | int cpuidle_register_device(struct cpuidle_device *dev) | |
476 | { | |
c878a52d | 477 | int ret = -EBUSY; |
dcb84f33 | 478 | |
1b0a0e9a SB |
479 | if (!dev) |
480 | return -EINVAL; | |
481 | ||
dcb84f33 VP |
482 | mutex_lock(&cpuidle_lock); |
483 | ||
c878a52d DL |
484 | if (dev->registered) |
485 | goto out_unlock; | |
486 | ||
267d4bf8 | 487 | __cpuidle_device_init(dev); |
5df0aa73 | 488 | |
f6bb51a5 DL |
489 | ret = __cpuidle_register_device(dev); |
490 | if (ret) | |
491 | goto out_unlock; | |
492 | ||
493 | ret = cpuidle_add_sysfs(dev); | |
494 | if (ret) | |
495 | goto out_unregister; | |
dcb84f33 | 496 | |
10b9d3f8 | 497 | ret = cpuidle_enable_device(dev); |
f6bb51a5 DL |
498 | if (ret) |
499 | goto out_sysfs; | |
10b9d3f8 | 500 | |
4f86d3a8 LB |
501 | cpuidle_install_idle_handler(); |
502 | ||
f6bb51a5 | 503 | out_unlock: |
4f86d3a8 LB |
504 | mutex_unlock(&cpuidle_lock); |
505 | ||
f6bb51a5 DL |
506 | return ret; |
507 | ||
508 | out_sysfs: | |
509 | cpuidle_remove_sysfs(dev); | |
510 | out_unregister: | |
511 | __cpuidle_unregister_device(dev); | |
512 | goto out_unlock; | |
4f86d3a8 LB |
513 | } |
514 | ||
515 | EXPORT_SYMBOL_GPL(cpuidle_register_device); | |
516 | ||
517 | /** | |
518 | * cpuidle_unregister_device - unregisters a CPU's idle PM feature | |
519 | * @dev: the cpu | |
520 | */ | |
521 | void cpuidle_unregister_device(struct cpuidle_device *dev) | |
522 | { | |
813e8e3d | 523 | if (!dev || dev->registered == 0) |
dcb84f33 VP |
524 | return; |
525 | ||
4f86d3a8 LB |
526 | cpuidle_pause_and_lock(); |
527 | ||
528 | cpuidle_disable_device(dev); | |
529 | ||
1aef40e2 | 530 | cpuidle_remove_sysfs(dev); |
f6bb51a5 DL |
531 | |
532 | __cpuidle_unregister_device(dev); | |
4f86d3a8 | 533 | |
4126c019 CC |
534 | cpuidle_coupled_unregister_device(dev); |
535 | ||
4f86d3a8 | 536 | cpuidle_resume_and_unlock(); |
4f86d3a8 LB |
537 | } |
538 | ||
539 | EXPORT_SYMBOL_GPL(cpuidle_unregister_device); | |
540 | ||
1c192d04 | 541 | /** |
4c637b21 DL |
542 | * cpuidle_unregister: unregister a driver and the devices. This function |
543 | * can be used only if the driver has been previously registered through | |
544 | * the cpuidle_register function. | |
545 | * | |
546 | * @drv: a valid pointer to a struct cpuidle_driver | |
547 | */ | |
548 | void cpuidle_unregister(struct cpuidle_driver *drv) | |
549 | { | |
550 | int cpu; | |
551 | struct cpuidle_device *device; | |
552 | ||
82467a5a | 553 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
554 | device = &per_cpu(cpuidle_dev, cpu); |
555 | cpuidle_unregister_device(device); | |
556 | } | |
557 | ||
558 | cpuidle_unregister_driver(drv); | |
559 | } | |
560 | EXPORT_SYMBOL_GPL(cpuidle_unregister); | |
561 | ||
562 | /** | |
563 | * cpuidle_register: registers the driver and the cpu devices with the | |
564 | * coupled_cpus passed as parameter. This function is used for all common | |
565 | * initialization pattern there are in the arch specific drivers. The | |
566 | * devices is globally defined in this file. | |
567 | * | |
568 | * @drv : a valid pointer to a struct cpuidle_driver | |
569 | * @coupled_cpus: a cpumask for the coupled states | |
570 | * | |
571 | * Returns 0 on success, < 0 otherwise | |
572 | */ | |
573 | int cpuidle_register(struct cpuidle_driver *drv, | |
574 | const struct cpumask *const coupled_cpus) | |
575 | { | |
576 | int ret, cpu; | |
577 | struct cpuidle_device *device; | |
578 | ||
579 | ret = cpuidle_register_driver(drv); | |
580 | if (ret) { | |
581 | pr_err("failed to register cpuidle driver\n"); | |
582 | return ret; | |
583 | } | |
584 | ||
82467a5a | 585 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
586 | device = &per_cpu(cpuidle_dev, cpu); |
587 | device->cpu = cpu; | |
588 | ||
589 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED | |
590 | /* | |
caf4a36e | 591 | * On multiplatform for ARM, the coupled idle states could be |
4c637b21 DL |
592 | * enabled in the kernel even if the cpuidle driver does not |
593 | * use it. Note, coupled_cpus is a struct copy. | |
594 | */ | |
595 | if (coupled_cpus) | |
596 | device->coupled_cpus = *coupled_cpus; | |
597 | #endif | |
598 | ret = cpuidle_register_device(device); | |
599 | if (!ret) | |
600 | continue; | |
601 | ||
602 | pr_err("Failed to register cpuidle device for cpu%d\n", cpu); | |
603 | ||
604 | cpuidle_unregister(drv); | |
605 | break; | |
606 | } | |
607 | ||
608 | return ret; | |
609 | } | |
610 | EXPORT_SYMBOL_GPL(cpuidle_register); | |
611 | ||
4f86d3a8 LB |
612 | #ifdef CONFIG_SMP |
613 | ||
4f86d3a8 LB |
614 | /* |
615 | * This function gets called when a part of the kernel has a new latency | |
616 | * requirement. This means we need to get all processors out of their C-state, | |
617 | * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that | |
618 | * wakes them all right up. | |
619 | */ | |
620 | static int cpuidle_latency_notify(struct notifier_block *b, | |
621 | unsigned long l, void *v) | |
622 | { | |
2ed903c5 | 623 | wake_up_all_idle_cpus(); |
4f86d3a8 LB |
624 | return NOTIFY_OK; |
625 | } | |
626 | ||
627 | static struct notifier_block cpuidle_latency_notifier = { | |
628 | .notifier_call = cpuidle_latency_notify, | |
629 | }; | |
630 | ||
d82b3518 MG |
631 | static inline void latency_notifier_init(struct notifier_block *n) |
632 | { | |
633 | pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n); | |
634 | } | |
4f86d3a8 LB |
635 | |
636 | #else /* CONFIG_SMP */ | |
637 | ||
638 | #define latency_notifier_init(x) do { } while (0) | |
639 | ||
640 | #endif /* CONFIG_SMP */ | |
641 | ||
642 | /** | |
643 | * cpuidle_init - core initializer | |
644 | */ | |
645 | static int __init cpuidle_init(void) | |
646 | { | |
647 | int ret; | |
648 | ||
62027aea LB |
649 | if (cpuidle_disabled()) |
650 | return -ENODEV; | |
651 | ||
8a25a2fd | 652 | ret = cpuidle_add_interface(cpu_subsys.dev_root); |
4f86d3a8 LB |
653 | if (ret) |
654 | return ret; | |
655 | ||
656 | latency_notifier_init(&cpuidle_latency_notifier); | |
657 | ||
658 | return 0; | |
659 | } | |
660 | ||
62027aea | 661 | module_param(off, int, 0444); |
4f86d3a8 | 662 | core_initcall(cpuidle_init); |