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 | ||
0e7414b7 RW |
100 | /** |
101 | * cpuidle_use_deepest_state - Set/clear governor override flag. | |
102 | * @enable: New value of the flag. | |
103 | * | |
104 | * Set/unset the current CPU to use the deepest idle state (override governors | |
105 | * going forward if set). | |
106 | */ | |
bb8313b6 JP |
107 | void cpuidle_use_deepest_state(bool enable) |
108 | { | |
109 | struct cpuidle_device *dev; | |
110 | ||
111 | preempt_disable(); | |
112 | dev = cpuidle_get_device(); | |
113 | dev->use_deepest_state = enable; | |
114 | preempt_enable(); | |
115 | } | |
116 | ||
ef2b22ac RW |
117 | /** |
118 | * cpuidle_find_deepest_state - Find the deepest available idle state. | |
119 | * @drv: cpuidle driver for the given CPU. | |
120 | * @dev: cpuidle device for the given CPU. | |
121 | */ | |
122 | int cpuidle_find_deepest_state(struct cpuidle_driver *drv, | |
123 | struct cpuidle_device *dev) | |
124 | { | |
0d94039f | 125 | return find_deepest_state(drv, dev, UINT_MAX, 0, false); |
ef2b22ac RW |
126 | } |
127 | ||
bb8313b6 | 128 | #ifdef CONFIG_SUSPEND |
124cf911 RW |
129 | static void enter_freeze_proper(struct cpuidle_driver *drv, |
130 | struct cpuidle_device *dev, int index) | |
131 | { | |
ae0afb4f RW |
132 | /* |
133 | * trace_suspend_resume() called by tick_freeze() for the last CPU | |
134 | * executing it contains RCU usage regarded as invalid in the idle | |
135 | * context, so tell RCU about that. | |
136 | */ | |
137 | RCU_NONIDLE(tick_freeze()); | |
124cf911 RW |
138 | /* |
139 | * The state used here cannot be a "coupled" one, because the "coupled" | |
140 | * cpuidle mechanism enables interrupts and doing that with timekeeping | |
141 | * suspended is generally unsafe. | |
142 | */ | |
63caae84 | 143 | stop_critical_timings(); |
124cf911 RW |
144 | drv->states[index].enter_freeze(dev, drv, index); |
145 | WARN_ON(!irqs_disabled()); | |
146 | /* | |
147 | * timekeeping_resume() that will be called by tick_unfreeze() for the | |
ae0afb4f | 148 | * first CPU executing it calls functions containing RCU read-side |
124cf911 RW |
149 | * critical sections, so tell RCU about that. |
150 | */ | |
151 | RCU_NONIDLE(tick_unfreeze()); | |
63caae84 | 152 | start_critical_timings(); |
124cf911 RW |
153 | } |
154 | ||
38106313 RW |
155 | /** |
156 | * cpuidle_enter_freeze - Enter an idle state suitable for suspend-to-idle. | |
ef2b22ac RW |
157 | * @drv: cpuidle driver for the given CPU. |
158 | * @dev: cpuidle device for the given CPU. | |
38106313 | 159 | * |
124cf911 | 160 | * If there are states with the ->enter_freeze callback, find the deepest of |
ef2b22ac | 161 | * them and enter it with frozen tick. |
38106313 | 162 | */ |
ef2b22ac | 163 | int cpuidle_enter_freeze(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
38106313 | 164 | { |
38106313 RW |
165 | int index; |
166 | ||
124cf911 RW |
167 | /* |
168 | * Find the deepest state with ->enter_freeze present, which guarantees | |
169 | * that interrupts won't be enabled when it exits and allows the tick to | |
170 | * be frozen safely. | |
171 | */ | |
0d94039f | 172 | index = find_deepest_state(drv, dev, UINT_MAX, 0, true); |
6f16886b | 173 | if (index > 0) |
124cf911 | 174 | enter_freeze_proper(drv, dev, index); |
124cf911 | 175 | |
ef2b22ac | 176 | return index; |
38106313 | 177 | } |
87e9b9f1 | 178 | #endif /* CONFIG_SUSPEND */ |
38106313 | 179 | |
56cfbf74 CC |
180 | /** |
181 | * cpuidle_enter_state - enter the state and update stats | |
182 | * @dev: cpuidle device for this cpu | |
183 | * @drv: cpuidle driver for this cpu | |
7312280b | 184 | * @index: index into the states table in @drv of the state to enter |
56cfbf74 CC |
185 | */ |
186 | int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, | |
554c06ba | 187 | int index) |
56cfbf74 CC |
188 | { |
189 | int entered_state; | |
190 | ||
554c06ba | 191 | struct cpuidle_state *target_state = &drv->states[index]; |
df8d9eea | 192 | bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP); |
dbd1b8ea | 193 | ktime_t time_start, time_end; |
554c06ba DL |
194 | s64 diff; |
195 | ||
df8d9eea RW |
196 | /* |
197 | * Tell the time framework to switch to a broadcast timer because our | |
198 | * local timer will be shut down. If a local timer is used from another | |
199 | * CPU as a broadcast timer, this call may fail if it is not available. | |
200 | */ | |
827a5aef | 201 | if (broadcast && tick_broadcast_enter()) { |
0d94039f RW |
202 | index = find_deepest_state(drv, dev, target_state->exit_latency, |
203 | CPUIDLE_FLAG_TIMER_STOP, false); | |
204 | if (index < 0) { | |
205 | default_idle_call(); | |
206 | return -EBUSY; | |
207 | } | |
208 | target_state = &drv->states[index]; | |
827a5aef | 209 | } |
df8d9eea | 210 | |
faad3849 RW |
211 | /* Take note of the planned idle state. */ |
212 | sched_idle_set_state(target_state); | |
213 | ||
30fe6884 | 214 | trace_cpu_idle_rcuidle(index, dev->cpu); |
dbd1b8ea | 215 | time_start = ns_to_ktime(local_clock()); |
554c06ba | 216 | |
63caae84 | 217 | stop_critical_timings(); |
554c06ba | 218 | entered_state = target_state->enter(dev, drv, index); |
63caae84 | 219 | start_critical_timings(); |
554c06ba | 220 | |
dbd1b8ea | 221 | time_end = ns_to_ktime(local_clock()); |
30fe6884 | 222 | trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); |
554c06ba | 223 | |
faad3849 RW |
224 | /* The cpu is no longer idle or about to enter idle. */ |
225 | sched_idle_set_state(NULL); | |
226 | ||
df8d9eea RW |
227 | if (broadcast) { |
228 | if (WARN_ON_ONCE(!irqs_disabled())) | |
229 | local_irq_disable(); | |
230 | ||
231 | tick_broadcast_exit(); | |
232 | } | |
233 | ||
e7387da5 | 234 | if (!cpuidle_state_is_coupled(drv, index)) |
0b89e9aa | 235 | local_irq_enable(); |
554c06ba | 236 | |
dbd1b8ea | 237 | diff = ktime_us_delta(time_end, time_start); |
554c06ba DL |
238 | if (diff > INT_MAX) |
239 | diff = INT_MAX; | |
240 | ||
241 | dev->last_residency = (int) diff; | |
56cfbf74 CC |
242 | |
243 | if (entered_state >= 0) { | |
244 | /* Update cpuidle counters */ | |
245 | /* This can be moved to within driver enter routine | |
246 | * but that results in multiple copies of same code. | |
247 | */ | |
a474a515 | 248 | dev->states_usage[entered_state].time += dev->last_residency; |
56cfbf74 CC |
249 | dev->states_usage[entered_state].usage++; |
250 | } else { | |
251 | dev->last_residency = 0; | |
252 | } | |
253 | ||
254 | return entered_state; | |
255 | } | |
256 | ||
4f86d3a8 | 257 | /** |
907e30f1 DL |
258 | * cpuidle_select - ask the cpuidle framework to choose an idle state |
259 | * | |
260 | * @drv: the cpuidle driver | |
261 | * @dev: the cpuidle device | |
4f86d3a8 | 262 | * |
51164251 | 263 | * Returns the index of the idle state. The return value must not be negative. |
4f86d3a8 | 264 | */ |
907e30f1 | 265 | int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
4f86d3a8 | 266 | { |
907e30f1 DL |
267 | return cpuidle_curr_governor->select(drv, dev); |
268 | } | |
ba8f20c2 | 269 | |
907e30f1 DL |
270 | /** |
271 | * cpuidle_enter - enter into the specified idle state | |
272 | * | |
273 | * @drv: the cpuidle driver tied with the cpu | |
274 | * @dev: the cpuidle device | |
275 | * @index: the index in the idle state table | |
276 | * | |
277 | * Returns the index in the idle state, < 0 in case of error. | |
278 | * The error code depends on the backend driver | |
279 | */ | |
280 | int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, | |
281 | int index) | |
282 | { | |
4c1ed5a6 | 283 | if (cpuidle_state_is_coupled(drv, index)) |
907e30f1 DL |
284 | return cpuidle_enter_state_coupled(dev, drv, index); |
285 | return cpuidle_enter_state(dev, drv, index); | |
286 | } | |
b60e6a0e | 287 | |
907e30f1 DL |
288 | /** |
289 | * cpuidle_reflect - tell the underlying governor what was the state | |
290 | * we were in | |
291 | * | |
292 | * @dev : the cpuidle device | |
293 | * @index: the index in the idle state table | |
294 | * | |
295 | */ | |
296 | void cpuidle_reflect(struct cpuidle_device *dev, int index) | |
297 | { | |
a802ea96 | 298 | if (cpuidle_curr_governor->reflect && index >= 0) |
907e30f1 | 299 | cpuidle_curr_governor->reflect(dev, index); |
4f86d3a8 LB |
300 | } |
301 | ||
302 | /** | |
303 | * cpuidle_install_idle_handler - installs the cpuidle idle loop handler | |
304 | */ | |
305 | void cpuidle_install_idle_handler(void) | |
306 | { | |
a0bfa137 | 307 | if (enabled_devices) { |
4f86d3a8 LB |
308 | /* Make sure all changes finished before we switch to new idle */ |
309 | smp_wmb(); | |
a0bfa137 | 310 | initialized = 1; |
4f86d3a8 LB |
311 | } |
312 | } | |
313 | ||
314 | /** | |
315 | * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler | |
316 | */ | |
317 | void cpuidle_uninstall_idle_handler(void) | |
318 | { | |
a0bfa137 LB |
319 | if (enabled_devices) { |
320 | initialized = 0; | |
2ed903c5 | 321 | wake_up_all_idle_cpus(); |
4f86d3a8 | 322 | } |
442bf3aa DL |
323 | |
324 | /* | |
325 | * Make sure external observers (such as the scheduler) | |
326 | * are done looking at pointed idle states. | |
327 | */ | |
328 | synchronize_rcu(); | |
4f86d3a8 LB |
329 | } |
330 | ||
331 | /** | |
332 | * cpuidle_pause_and_lock - temporarily disables CPUIDLE | |
333 | */ | |
334 | void cpuidle_pause_and_lock(void) | |
335 | { | |
336 | mutex_lock(&cpuidle_lock); | |
337 | cpuidle_uninstall_idle_handler(); | |
338 | } | |
339 | ||
340 | EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock); | |
341 | ||
342 | /** | |
343 | * cpuidle_resume_and_unlock - resumes CPUIDLE operation | |
344 | */ | |
345 | void cpuidle_resume_and_unlock(void) | |
346 | { | |
347 | cpuidle_install_idle_handler(); | |
348 | mutex_unlock(&cpuidle_lock); | |
349 | } | |
350 | ||
351 | EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); | |
352 | ||
8651f97b PM |
353 | /* Currently used in suspend/resume path to suspend cpuidle */ |
354 | void cpuidle_pause(void) | |
355 | { | |
356 | mutex_lock(&cpuidle_lock); | |
357 | cpuidle_uninstall_idle_handler(); | |
358 | mutex_unlock(&cpuidle_lock); | |
359 | } | |
360 | ||
361 | /* Currently used in suspend/resume path to resume cpuidle */ | |
362 | void cpuidle_resume(void) | |
363 | { | |
364 | mutex_lock(&cpuidle_lock); | |
365 | cpuidle_install_idle_handler(); | |
366 | mutex_unlock(&cpuidle_lock); | |
367 | } | |
368 | ||
4f86d3a8 LB |
369 | /** |
370 | * cpuidle_enable_device - enables idle PM for a CPU | |
371 | * @dev: the CPU | |
372 | * | |
373 | * This function must be called between cpuidle_pause_and_lock and | |
374 | * cpuidle_resume_and_unlock when used externally. | |
375 | */ | |
376 | int cpuidle_enable_device(struct cpuidle_device *dev) | |
377 | { | |
5df0aa73 | 378 | int ret; |
bf4d1b5d | 379 | struct cpuidle_driver *drv; |
4f86d3a8 | 380 | |
1b0a0e9a SB |
381 | if (!dev) |
382 | return -EINVAL; | |
383 | ||
4f86d3a8 LB |
384 | if (dev->enabled) |
385 | return 0; | |
bf4d1b5d DL |
386 | |
387 | drv = cpuidle_get_cpu_driver(dev); | |
388 | ||
e1689795 | 389 | if (!drv || !cpuidle_curr_governor) |
4f86d3a8 | 390 | return -EIO; |
bf4d1b5d | 391 | |
10b9d3f8 DL |
392 | if (!dev->registered) |
393 | return -EINVAL; | |
394 | ||
bf4d1b5d DL |
395 | ret = cpuidle_add_device_sysfs(dev); |
396 | if (ret) | |
4f86d3a8 LB |
397 | return ret; |
398 | ||
399 | if (cpuidle_curr_governor->enable && | |
e1689795 | 400 | (ret = cpuidle_curr_governor->enable(drv, dev))) |
4f86d3a8 LB |
401 | goto fail_sysfs; |
402 | ||
4f86d3a8 LB |
403 | smp_wmb(); |
404 | ||
405 | dev->enabled = 1; | |
406 | ||
407 | enabled_devices++; | |
408 | return 0; | |
409 | ||
410 | fail_sysfs: | |
bf4d1b5d | 411 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
412 | |
413 | return ret; | |
414 | } | |
415 | ||
416 | EXPORT_SYMBOL_GPL(cpuidle_enable_device); | |
417 | ||
418 | /** | |
419 | * cpuidle_disable_device - disables idle PM for a CPU | |
420 | * @dev: the CPU | |
421 | * | |
422 | * This function must be called between cpuidle_pause_and_lock and | |
423 | * cpuidle_resume_and_unlock when used externally. | |
424 | */ | |
425 | void cpuidle_disable_device(struct cpuidle_device *dev) | |
426 | { | |
bf4d1b5d DL |
427 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
428 | ||
cf31cd1a | 429 | if (!dev || !dev->enabled) |
4f86d3a8 | 430 | return; |
bf4d1b5d DL |
431 | |
432 | if (!drv || !cpuidle_curr_governor) | |
4f86d3a8 LB |
433 | return; |
434 | ||
435 | dev->enabled = 0; | |
436 | ||
437 | if (cpuidle_curr_governor->disable) | |
bf4d1b5d | 438 | cpuidle_curr_governor->disable(drv, dev); |
4f86d3a8 | 439 | |
bf4d1b5d | 440 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
441 | enabled_devices--; |
442 | } | |
443 | ||
444 | EXPORT_SYMBOL_GPL(cpuidle_disable_device); | |
445 | ||
f6bb51a5 DL |
446 | static void __cpuidle_unregister_device(struct cpuidle_device *dev) |
447 | { | |
448 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); | |
449 | ||
450 | list_del(&dev->device_list); | |
451 | per_cpu(cpuidle_devices, dev->cpu) = NULL; | |
452 | module_put(drv->owner); | |
c998c078 DG |
453 | |
454 | dev->registered = 0; | |
f6bb51a5 DL |
455 | } |
456 | ||
267d4bf8 | 457 | static void __cpuidle_device_init(struct cpuidle_device *dev) |
5df0aa73 DL |
458 | { |
459 | memset(dev->states_usage, 0, sizeof(dev->states_usage)); | |
460 | dev->last_residency = 0; | |
5df0aa73 DL |
461 | } |
462 | ||
4f86d3a8 | 463 | /** |
dcb84f33 VP |
464 | * __cpuidle_register_device - internal register function called before register |
465 | * and enable routines | |
4f86d3a8 | 466 | * @dev: the cpu |
dcb84f33 VP |
467 | * |
468 | * cpuidle_lock mutex must be held before this is called | |
4f86d3a8 | 469 | */ |
dcb84f33 | 470 | static int __cpuidle_register_device(struct cpuidle_device *dev) |
4f86d3a8 LB |
471 | { |
472 | int ret; | |
bf4d1b5d | 473 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
4f86d3a8 | 474 | |
bf4d1b5d | 475 | if (!try_module_get(drv->owner)) |
4f86d3a8 LB |
476 | return -EINVAL; |
477 | ||
4f86d3a8 LB |
478 | per_cpu(cpuidle_devices, dev->cpu) = dev; |
479 | list_add(&dev->device_list, &cpuidle_detected_devices); | |
4f86d3a8 | 480 | |
4126c019 | 481 | ret = cpuidle_coupled_register_device(dev); |
47182668 | 482 | if (ret) |
f6bb51a5 | 483 | __cpuidle_unregister_device(dev); |
47182668 VK |
484 | else |
485 | dev->registered = 1; | |
4f86d3a8 | 486 | |
47182668 | 487 | return ret; |
dcb84f33 VP |
488 | } |
489 | ||
490 | /** | |
491 | * cpuidle_register_device - registers a CPU's idle PM feature | |
492 | * @dev: the cpu | |
493 | */ | |
494 | int cpuidle_register_device(struct cpuidle_device *dev) | |
495 | { | |
c878a52d | 496 | int ret = -EBUSY; |
dcb84f33 | 497 | |
1b0a0e9a SB |
498 | if (!dev) |
499 | return -EINVAL; | |
500 | ||
dcb84f33 VP |
501 | mutex_lock(&cpuidle_lock); |
502 | ||
c878a52d DL |
503 | if (dev->registered) |
504 | goto out_unlock; | |
505 | ||
267d4bf8 | 506 | __cpuidle_device_init(dev); |
5df0aa73 | 507 | |
f6bb51a5 DL |
508 | ret = __cpuidle_register_device(dev); |
509 | if (ret) | |
510 | goto out_unlock; | |
511 | ||
512 | ret = cpuidle_add_sysfs(dev); | |
513 | if (ret) | |
514 | goto out_unregister; | |
dcb84f33 | 515 | |
10b9d3f8 | 516 | ret = cpuidle_enable_device(dev); |
f6bb51a5 DL |
517 | if (ret) |
518 | goto out_sysfs; | |
10b9d3f8 | 519 | |
4f86d3a8 LB |
520 | cpuidle_install_idle_handler(); |
521 | ||
f6bb51a5 | 522 | out_unlock: |
4f86d3a8 LB |
523 | mutex_unlock(&cpuidle_lock); |
524 | ||
f6bb51a5 DL |
525 | return ret; |
526 | ||
527 | out_sysfs: | |
528 | cpuidle_remove_sysfs(dev); | |
529 | out_unregister: | |
530 | __cpuidle_unregister_device(dev); | |
531 | goto out_unlock; | |
4f86d3a8 LB |
532 | } |
533 | ||
534 | EXPORT_SYMBOL_GPL(cpuidle_register_device); | |
535 | ||
536 | /** | |
537 | * cpuidle_unregister_device - unregisters a CPU's idle PM feature | |
538 | * @dev: the cpu | |
539 | */ | |
540 | void cpuidle_unregister_device(struct cpuidle_device *dev) | |
541 | { | |
813e8e3d | 542 | if (!dev || dev->registered == 0) |
dcb84f33 VP |
543 | return; |
544 | ||
4f86d3a8 LB |
545 | cpuidle_pause_and_lock(); |
546 | ||
547 | cpuidle_disable_device(dev); | |
548 | ||
1aef40e2 | 549 | cpuidle_remove_sysfs(dev); |
f6bb51a5 DL |
550 | |
551 | __cpuidle_unregister_device(dev); | |
4f86d3a8 | 552 | |
4126c019 CC |
553 | cpuidle_coupled_unregister_device(dev); |
554 | ||
4f86d3a8 | 555 | cpuidle_resume_and_unlock(); |
4f86d3a8 LB |
556 | } |
557 | ||
558 | EXPORT_SYMBOL_GPL(cpuidle_unregister_device); | |
559 | ||
1c192d04 | 560 | /** |
4c637b21 DL |
561 | * cpuidle_unregister: unregister a driver and the devices. This function |
562 | * can be used only if the driver has been previously registered through | |
563 | * the cpuidle_register function. | |
564 | * | |
565 | * @drv: a valid pointer to a struct cpuidle_driver | |
566 | */ | |
567 | void cpuidle_unregister(struct cpuidle_driver *drv) | |
568 | { | |
569 | int cpu; | |
570 | struct cpuidle_device *device; | |
571 | ||
82467a5a | 572 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
573 | device = &per_cpu(cpuidle_dev, cpu); |
574 | cpuidle_unregister_device(device); | |
575 | } | |
576 | ||
577 | cpuidle_unregister_driver(drv); | |
578 | } | |
579 | EXPORT_SYMBOL_GPL(cpuidle_unregister); | |
580 | ||
581 | /** | |
582 | * cpuidle_register: registers the driver and the cpu devices with the | |
583 | * coupled_cpus passed as parameter. This function is used for all common | |
584 | * initialization pattern there are in the arch specific drivers. The | |
585 | * devices is globally defined in this file. | |
586 | * | |
587 | * @drv : a valid pointer to a struct cpuidle_driver | |
588 | * @coupled_cpus: a cpumask for the coupled states | |
589 | * | |
590 | * Returns 0 on success, < 0 otherwise | |
591 | */ | |
592 | int cpuidle_register(struct cpuidle_driver *drv, | |
593 | const struct cpumask *const coupled_cpus) | |
594 | { | |
595 | int ret, cpu; | |
596 | struct cpuidle_device *device; | |
597 | ||
598 | ret = cpuidle_register_driver(drv); | |
599 | if (ret) { | |
600 | pr_err("failed to register cpuidle driver\n"); | |
601 | return ret; | |
602 | } | |
603 | ||
82467a5a | 604 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
605 | device = &per_cpu(cpuidle_dev, cpu); |
606 | device->cpu = cpu; | |
607 | ||
608 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED | |
609 | /* | |
caf4a36e | 610 | * On multiplatform for ARM, the coupled idle states could be |
4c637b21 DL |
611 | * enabled in the kernel even if the cpuidle driver does not |
612 | * use it. Note, coupled_cpus is a struct copy. | |
613 | */ | |
614 | if (coupled_cpus) | |
615 | device->coupled_cpus = *coupled_cpus; | |
616 | #endif | |
617 | ret = cpuidle_register_device(device); | |
618 | if (!ret) | |
619 | continue; | |
620 | ||
621 | pr_err("Failed to register cpuidle device for cpu%d\n", cpu); | |
622 | ||
623 | cpuidle_unregister(drv); | |
624 | break; | |
625 | } | |
626 | ||
627 | return ret; | |
628 | } | |
629 | EXPORT_SYMBOL_GPL(cpuidle_register); | |
630 | ||
4f86d3a8 LB |
631 | #ifdef CONFIG_SMP |
632 | ||
4f86d3a8 LB |
633 | /* |
634 | * This function gets called when a part of the kernel has a new latency | |
635 | * requirement. This means we need to get all processors out of their C-state, | |
636 | * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that | |
637 | * wakes them all right up. | |
638 | */ | |
639 | static int cpuidle_latency_notify(struct notifier_block *b, | |
640 | unsigned long l, void *v) | |
641 | { | |
2ed903c5 | 642 | wake_up_all_idle_cpus(); |
4f86d3a8 LB |
643 | return NOTIFY_OK; |
644 | } | |
645 | ||
646 | static struct notifier_block cpuidle_latency_notifier = { | |
647 | .notifier_call = cpuidle_latency_notify, | |
648 | }; | |
649 | ||
d82b3518 MG |
650 | static inline void latency_notifier_init(struct notifier_block *n) |
651 | { | |
652 | pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n); | |
653 | } | |
4f86d3a8 LB |
654 | |
655 | #else /* CONFIG_SMP */ | |
656 | ||
657 | #define latency_notifier_init(x) do { } while (0) | |
658 | ||
659 | #endif /* CONFIG_SMP */ | |
660 | ||
661 | /** | |
662 | * cpuidle_init - core initializer | |
663 | */ | |
664 | static int __init cpuidle_init(void) | |
665 | { | |
666 | int ret; | |
667 | ||
62027aea LB |
668 | if (cpuidle_disabled()) |
669 | return -ENODEV; | |
670 | ||
8a25a2fd | 671 | ret = cpuidle_add_interface(cpu_subsys.dev_root); |
4f86d3a8 LB |
672 | if (ret) |
673 | return ret; | |
674 | ||
675 | latency_notifier_init(&cpuidle_latency_notifier); | |
676 | ||
677 | return 0; | |
678 | } | |
679 | ||
62027aea | 680 | module_param(off, int, 0444); |
4f86d3a8 | 681 | core_initcall(cpuidle_init); |