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); |
e93e59ce | 176 | u64 time_start, time_end; |
554c06ba DL |
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); |
e93e59ce | 198 | time_start = local_clock(); |
554c06ba | 199 | |
63caae84 | 200 | stop_critical_timings(); |
554c06ba | 201 | entered_state = target_state->enter(dev, drv, index); |
63caae84 | 202 | start_critical_timings(); |
554c06ba | 203 | |
e93e59ce | 204 | time_end = local_clock(); |
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 | ||
e7387da5 | 217 | if (!cpuidle_state_is_coupled(drv, index)) |
0b89e9aa | 218 | local_irq_enable(); |
554c06ba | 219 | |
e93e59ce DL |
220 | /* |
221 | * local_clock() returns the time in nanosecond, let's shift | |
222 | * by 10 (divide by 1024) to have microsecond based time. | |
223 | */ | |
224 | diff = (time_end - time_start) >> 10; | |
554c06ba DL |
225 | if (diff > INT_MAX) |
226 | diff = INT_MAX; | |
227 | ||
228 | dev->last_residency = (int) diff; | |
56cfbf74 CC |
229 | |
230 | if (entered_state >= 0) { | |
231 | /* Update cpuidle counters */ | |
232 | /* This can be moved to within driver enter routine | |
233 | * but that results in multiple copies of same code. | |
234 | */ | |
a474a515 | 235 | dev->states_usage[entered_state].time += dev->last_residency; |
56cfbf74 CC |
236 | dev->states_usage[entered_state].usage++; |
237 | } else { | |
238 | dev->last_residency = 0; | |
239 | } | |
240 | ||
241 | return entered_state; | |
242 | } | |
243 | ||
4f86d3a8 | 244 | /** |
907e30f1 DL |
245 | * cpuidle_select - ask the cpuidle framework to choose an idle state |
246 | * | |
247 | * @drv: the cpuidle driver | |
248 | * @dev: the cpuidle device | |
4f86d3a8 | 249 | * |
51164251 | 250 | * Returns the index of the idle state. The return value must not be negative. |
4f86d3a8 | 251 | */ |
907e30f1 | 252 | int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
4f86d3a8 | 253 | { |
907e30f1 DL |
254 | return cpuidle_curr_governor->select(drv, dev); |
255 | } | |
ba8f20c2 | 256 | |
907e30f1 DL |
257 | /** |
258 | * cpuidle_enter - enter into the specified idle state | |
259 | * | |
260 | * @drv: the cpuidle driver tied with the cpu | |
261 | * @dev: the cpuidle device | |
262 | * @index: the index in the idle state table | |
263 | * | |
264 | * Returns the index in the idle state, < 0 in case of error. | |
265 | * The error code depends on the backend driver | |
266 | */ | |
267 | int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, | |
268 | int index) | |
269 | { | |
4c1ed5a6 | 270 | if (cpuidle_state_is_coupled(drv, index)) |
907e30f1 DL |
271 | return cpuidle_enter_state_coupled(dev, drv, index); |
272 | return cpuidle_enter_state(dev, drv, index); | |
273 | } | |
b60e6a0e | 274 | |
907e30f1 DL |
275 | /** |
276 | * cpuidle_reflect - tell the underlying governor what was the state | |
277 | * we were in | |
278 | * | |
279 | * @dev : the cpuidle device | |
280 | * @index: the index in the idle state table | |
281 | * | |
282 | */ | |
283 | void cpuidle_reflect(struct cpuidle_device *dev, int index) | |
284 | { | |
a802ea96 | 285 | if (cpuidle_curr_governor->reflect && index >= 0) |
907e30f1 | 286 | cpuidle_curr_governor->reflect(dev, index); |
4f86d3a8 LB |
287 | } |
288 | ||
289 | /** | |
290 | * cpuidle_install_idle_handler - installs the cpuidle idle loop handler | |
291 | */ | |
292 | void cpuidle_install_idle_handler(void) | |
293 | { | |
a0bfa137 | 294 | if (enabled_devices) { |
4f86d3a8 LB |
295 | /* Make sure all changes finished before we switch to new idle */ |
296 | smp_wmb(); | |
a0bfa137 | 297 | initialized = 1; |
4f86d3a8 LB |
298 | } |
299 | } | |
300 | ||
301 | /** | |
302 | * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler | |
303 | */ | |
304 | void cpuidle_uninstall_idle_handler(void) | |
305 | { | |
a0bfa137 LB |
306 | if (enabled_devices) { |
307 | initialized = 0; | |
2ed903c5 | 308 | wake_up_all_idle_cpus(); |
4f86d3a8 | 309 | } |
442bf3aa DL |
310 | |
311 | /* | |
312 | * Make sure external observers (such as the scheduler) | |
313 | * are done looking at pointed idle states. | |
314 | */ | |
315 | synchronize_rcu(); | |
4f86d3a8 LB |
316 | } |
317 | ||
318 | /** | |
319 | * cpuidle_pause_and_lock - temporarily disables CPUIDLE | |
320 | */ | |
321 | void cpuidle_pause_and_lock(void) | |
322 | { | |
323 | mutex_lock(&cpuidle_lock); | |
324 | cpuidle_uninstall_idle_handler(); | |
325 | } | |
326 | ||
327 | EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock); | |
328 | ||
329 | /** | |
330 | * cpuidle_resume_and_unlock - resumes CPUIDLE operation | |
331 | */ | |
332 | void cpuidle_resume_and_unlock(void) | |
333 | { | |
334 | cpuidle_install_idle_handler(); | |
335 | mutex_unlock(&cpuidle_lock); | |
336 | } | |
337 | ||
338 | EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); | |
339 | ||
8651f97b PM |
340 | /* Currently used in suspend/resume path to suspend cpuidle */ |
341 | void cpuidle_pause(void) | |
342 | { | |
343 | mutex_lock(&cpuidle_lock); | |
344 | cpuidle_uninstall_idle_handler(); | |
345 | mutex_unlock(&cpuidle_lock); | |
346 | } | |
347 | ||
348 | /* Currently used in suspend/resume path to resume cpuidle */ | |
349 | void cpuidle_resume(void) | |
350 | { | |
351 | mutex_lock(&cpuidle_lock); | |
352 | cpuidle_install_idle_handler(); | |
353 | mutex_unlock(&cpuidle_lock); | |
354 | } | |
355 | ||
4f86d3a8 LB |
356 | /** |
357 | * cpuidle_enable_device - enables 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 | int cpuidle_enable_device(struct cpuidle_device *dev) | |
364 | { | |
5df0aa73 | 365 | int ret; |
bf4d1b5d | 366 | struct cpuidle_driver *drv; |
4f86d3a8 | 367 | |
1b0a0e9a SB |
368 | if (!dev) |
369 | return -EINVAL; | |
370 | ||
4f86d3a8 LB |
371 | if (dev->enabled) |
372 | return 0; | |
bf4d1b5d DL |
373 | |
374 | drv = cpuidle_get_cpu_driver(dev); | |
375 | ||
e1689795 | 376 | if (!drv || !cpuidle_curr_governor) |
4f86d3a8 | 377 | return -EIO; |
bf4d1b5d | 378 | |
10b9d3f8 DL |
379 | if (!dev->registered) |
380 | return -EINVAL; | |
381 | ||
bf4d1b5d DL |
382 | ret = cpuidle_add_device_sysfs(dev); |
383 | if (ret) | |
4f86d3a8 LB |
384 | return ret; |
385 | ||
386 | if (cpuidle_curr_governor->enable && | |
e1689795 | 387 | (ret = cpuidle_curr_governor->enable(drv, dev))) |
4f86d3a8 LB |
388 | goto fail_sysfs; |
389 | ||
4f86d3a8 LB |
390 | smp_wmb(); |
391 | ||
392 | dev->enabled = 1; | |
393 | ||
394 | enabled_devices++; | |
395 | return 0; | |
396 | ||
397 | fail_sysfs: | |
bf4d1b5d | 398 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
399 | |
400 | return ret; | |
401 | } | |
402 | ||
403 | EXPORT_SYMBOL_GPL(cpuidle_enable_device); | |
404 | ||
405 | /** | |
406 | * cpuidle_disable_device - disables idle PM for a CPU | |
407 | * @dev: the CPU | |
408 | * | |
409 | * This function must be called between cpuidle_pause_and_lock and | |
410 | * cpuidle_resume_and_unlock when used externally. | |
411 | */ | |
412 | void cpuidle_disable_device(struct cpuidle_device *dev) | |
413 | { | |
bf4d1b5d DL |
414 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
415 | ||
cf31cd1a | 416 | if (!dev || !dev->enabled) |
4f86d3a8 | 417 | return; |
bf4d1b5d DL |
418 | |
419 | if (!drv || !cpuidle_curr_governor) | |
4f86d3a8 LB |
420 | return; |
421 | ||
422 | dev->enabled = 0; | |
423 | ||
424 | if (cpuidle_curr_governor->disable) | |
bf4d1b5d | 425 | cpuidle_curr_governor->disable(drv, dev); |
4f86d3a8 | 426 | |
bf4d1b5d | 427 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
428 | enabled_devices--; |
429 | } | |
430 | ||
431 | EXPORT_SYMBOL_GPL(cpuidle_disable_device); | |
432 | ||
f6bb51a5 DL |
433 | static void __cpuidle_unregister_device(struct cpuidle_device *dev) |
434 | { | |
435 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); | |
436 | ||
437 | list_del(&dev->device_list); | |
438 | per_cpu(cpuidle_devices, dev->cpu) = NULL; | |
439 | module_put(drv->owner); | |
c998c078 DG |
440 | |
441 | dev->registered = 0; | |
f6bb51a5 DL |
442 | } |
443 | ||
267d4bf8 | 444 | static void __cpuidle_device_init(struct cpuidle_device *dev) |
5df0aa73 DL |
445 | { |
446 | memset(dev->states_usage, 0, sizeof(dev->states_usage)); | |
447 | dev->last_residency = 0; | |
5df0aa73 DL |
448 | } |
449 | ||
4f86d3a8 | 450 | /** |
dcb84f33 VP |
451 | * __cpuidle_register_device - internal register function called before register |
452 | * and enable routines | |
4f86d3a8 | 453 | * @dev: the cpu |
dcb84f33 VP |
454 | * |
455 | * cpuidle_lock mutex must be held before this is called | |
4f86d3a8 | 456 | */ |
dcb84f33 | 457 | static int __cpuidle_register_device(struct cpuidle_device *dev) |
4f86d3a8 LB |
458 | { |
459 | int ret; | |
bf4d1b5d | 460 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
4f86d3a8 | 461 | |
bf4d1b5d | 462 | if (!try_module_get(drv->owner)) |
4f86d3a8 LB |
463 | return -EINVAL; |
464 | ||
4f86d3a8 LB |
465 | per_cpu(cpuidle_devices, dev->cpu) = dev; |
466 | list_add(&dev->device_list, &cpuidle_detected_devices); | |
4f86d3a8 | 467 | |
4126c019 | 468 | ret = cpuidle_coupled_register_device(dev); |
47182668 | 469 | if (ret) |
f6bb51a5 | 470 | __cpuidle_unregister_device(dev); |
47182668 VK |
471 | else |
472 | dev->registered = 1; | |
4f86d3a8 | 473 | |
47182668 | 474 | return ret; |
dcb84f33 VP |
475 | } |
476 | ||
477 | /** | |
478 | * cpuidle_register_device - registers a CPU's idle PM feature | |
479 | * @dev: the cpu | |
480 | */ | |
481 | int cpuidle_register_device(struct cpuidle_device *dev) | |
482 | { | |
c878a52d | 483 | int ret = -EBUSY; |
dcb84f33 | 484 | |
1b0a0e9a SB |
485 | if (!dev) |
486 | return -EINVAL; | |
487 | ||
dcb84f33 VP |
488 | mutex_lock(&cpuidle_lock); |
489 | ||
c878a52d DL |
490 | if (dev->registered) |
491 | goto out_unlock; | |
492 | ||
267d4bf8 | 493 | __cpuidle_device_init(dev); |
5df0aa73 | 494 | |
f6bb51a5 DL |
495 | ret = __cpuidle_register_device(dev); |
496 | if (ret) | |
497 | goto out_unlock; | |
498 | ||
499 | ret = cpuidle_add_sysfs(dev); | |
500 | if (ret) | |
501 | goto out_unregister; | |
dcb84f33 | 502 | |
10b9d3f8 | 503 | ret = cpuidle_enable_device(dev); |
f6bb51a5 DL |
504 | if (ret) |
505 | goto out_sysfs; | |
10b9d3f8 | 506 | |
4f86d3a8 LB |
507 | cpuidle_install_idle_handler(); |
508 | ||
f6bb51a5 | 509 | out_unlock: |
4f86d3a8 LB |
510 | mutex_unlock(&cpuidle_lock); |
511 | ||
f6bb51a5 DL |
512 | return ret; |
513 | ||
514 | out_sysfs: | |
515 | cpuidle_remove_sysfs(dev); | |
516 | out_unregister: | |
517 | __cpuidle_unregister_device(dev); | |
518 | goto out_unlock; | |
4f86d3a8 LB |
519 | } |
520 | ||
521 | EXPORT_SYMBOL_GPL(cpuidle_register_device); | |
522 | ||
523 | /** | |
524 | * cpuidle_unregister_device - unregisters a CPU's idle PM feature | |
525 | * @dev: the cpu | |
526 | */ | |
527 | void cpuidle_unregister_device(struct cpuidle_device *dev) | |
528 | { | |
813e8e3d | 529 | if (!dev || dev->registered == 0) |
dcb84f33 VP |
530 | return; |
531 | ||
4f86d3a8 LB |
532 | cpuidle_pause_and_lock(); |
533 | ||
534 | cpuidle_disable_device(dev); | |
535 | ||
1aef40e2 | 536 | cpuidle_remove_sysfs(dev); |
f6bb51a5 DL |
537 | |
538 | __cpuidle_unregister_device(dev); | |
4f86d3a8 | 539 | |
4126c019 CC |
540 | cpuidle_coupled_unregister_device(dev); |
541 | ||
4f86d3a8 | 542 | cpuidle_resume_and_unlock(); |
4f86d3a8 LB |
543 | } |
544 | ||
545 | EXPORT_SYMBOL_GPL(cpuidle_unregister_device); | |
546 | ||
1c192d04 | 547 | /** |
4c637b21 DL |
548 | * cpuidle_unregister: unregister a driver and the devices. This function |
549 | * can be used only if the driver has been previously registered through | |
550 | * the cpuidle_register function. | |
551 | * | |
552 | * @drv: a valid pointer to a struct cpuidle_driver | |
553 | */ | |
554 | void cpuidle_unregister(struct cpuidle_driver *drv) | |
555 | { | |
556 | int cpu; | |
557 | struct cpuidle_device *device; | |
558 | ||
82467a5a | 559 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
560 | device = &per_cpu(cpuidle_dev, cpu); |
561 | cpuidle_unregister_device(device); | |
562 | } | |
563 | ||
564 | cpuidle_unregister_driver(drv); | |
565 | } | |
566 | EXPORT_SYMBOL_GPL(cpuidle_unregister); | |
567 | ||
568 | /** | |
569 | * cpuidle_register: registers the driver and the cpu devices with the | |
570 | * coupled_cpus passed as parameter. This function is used for all common | |
571 | * initialization pattern there are in the arch specific drivers. The | |
572 | * devices is globally defined in this file. | |
573 | * | |
574 | * @drv : a valid pointer to a struct cpuidle_driver | |
575 | * @coupled_cpus: a cpumask for the coupled states | |
576 | * | |
577 | * Returns 0 on success, < 0 otherwise | |
578 | */ | |
579 | int cpuidle_register(struct cpuidle_driver *drv, | |
580 | const struct cpumask *const coupled_cpus) | |
581 | { | |
582 | int ret, cpu; | |
583 | struct cpuidle_device *device; | |
584 | ||
585 | ret = cpuidle_register_driver(drv); | |
586 | if (ret) { | |
587 | pr_err("failed to register cpuidle driver\n"); | |
588 | return ret; | |
589 | } | |
590 | ||
82467a5a | 591 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
592 | device = &per_cpu(cpuidle_dev, cpu); |
593 | device->cpu = cpu; | |
594 | ||
595 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED | |
596 | /* | |
caf4a36e | 597 | * On multiplatform for ARM, the coupled idle states could be |
4c637b21 DL |
598 | * enabled in the kernel even if the cpuidle driver does not |
599 | * use it. Note, coupled_cpus is a struct copy. | |
600 | */ | |
601 | if (coupled_cpus) | |
602 | device->coupled_cpus = *coupled_cpus; | |
603 | #endif | |
604 | ret = cpuidle_register_device(device); | |
605 | if (!ret) | |
606 | continue; | |
607 | ||
608 | pr_err("Failed to register cpuidle device for cpu%d\n", cpu); | |
609 | ||
610 | cpuidle_unregister(drv); | |
611 | break; | |
612 | } | |
613 | ||
614 | return ret; | |
615 | } | |
616 | EXPORT_SYMBOL_GPL(cpuidle_register); | |
617 | ||
4f86d3a8 LB |
618 | #ifdef CONFIG_SMP |
619 | ||
4f86d3a8 LB |
620 | /* |
621 | * This function gets called when a part of the kernel has a new latency | |
622 | * requirement. This means we need to get all processors out of their C-state, | |
623 | * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that | |
624 | * wakes them all right up. | |
625 | */ | |
626 | static int cpuidle_latency_notify(struct notifier_block *b, | |
627 | unsigned long l, void *v) | |
628 | { | |
2ed903c5 | 629 | wake_up_all_idle_cpus(); |
4f86d3a8 LB |
630 | return NOTIFY_OK; |
631 | } | |
632 | ||
633 | static struct notifier_block cpuidle_latency_notifier = { | |
634 | .notifier_call = cpuidle_latency_notify, | |
635 | }; | |
636 | ||
d82b3518 MG |
637 | static inline void latency_notifier_init(struct notifier_block *n) |
638 | { | |
639 | pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n); | |
640 | } | |
4f86d3a8 LB |
641 | |
642 | #else /* CONFIG_SMP */ | |
643 | ||
644 | #define latency_notifier_init(x) do { } while (0) | |
645 | ||
646 | #endif /* CONFIG_SMP */ | |
647 | ||
648 | /** | |
649 | * cpuidle_init - core initializer | |
650 | */ | |
651 | static int __init cpuidle_init(void) | |
652 | { | |
653 | int ret; | |
654 | ||
62027aea LB |
655 | if (cpuidle_disabled()) |
656 | return -ENODEV; | |
657 | ||
8a25a2fd | 658 | ret = cpuidle_add_interface(cpu_subsys.dev_root); |
4f86d3a8 LB |
659 | if (ret) |
660 | return ret; | |
661 | ||
662 | latency_notifier_init(&cpuidle_latency_notifier); | |
663 | ||
664 | return 0; | |
665 | } | |
666 | ||
62027aea | 667 | module_param(off, int, 0444); |
4f86d3a8 | 668 | core_initcall(cpuidle_init); |