]>
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> | |
e6017571 | 15 | #include <linux/sched/clock.h> |
4f86d3a8 | 16 | #include <linux/notifier.h> |
e8db0be1 | 17 | #include <linux/pm_qos.h> |
4f86d3a8 LB |
18 | #include <linux/cpu.h> |
19 | #include <linux/cpuidle.h> | |
9a0b8415 | 20 | #include <linux/ktime.h> |
2e94d1f7 | 21 | #include <linux/hrtimer.h> |
884b17e1 | 22 | #include <linux/module.h> |
38106313 | 23 | #include <linux/suspend.h> |
124cf911 | 24 | #include <linux/tick.h> |
288f023e | 25 | #include <trace/events/power.h> |
4f86d3a8 LB |
26 | |
27 | #include "cpuidle.h" | |
28 | ||
29 | DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices); | |
4c637b21 | 30 | DEFINE_PER_CPU(struct cpuidle_device, cpuidle_dev); |
4f86d3a8 LB |
31 | |
32 | DEFINE_MUTEX(cpuidle_lock); | |
33 | LIST_HEAD(cpuidle_detected_devices); | |
4f86d3a8 LB |
34 | |
35 | static int enabled_devices; | |
62027aea | 36 | static int off __read_mostly; |
a0bfa137 | 37 | static int initialized __read_mostly; |
62027aea LB |
38 | |
39 | int cpuidle_disabled(void) | |
40 | { | |
41 | return off; | |
42 | } | |
d91ee586 LB |
43 | void disable_cpuidle(void) |
44 | { | |
45 | off = 1; | |
46 | } | |
4f86d3a8 | 47 | |
ef2b22ac RW |
48 | bool cpuidle_not_available(struct cpuidle_driver *drv, |
49 | struct cpuidle_device *dev) | |
31a34090 RW |
50 | { |
51 | return off || !initialized || !drv || !dev || !dev->enabled; | |
52 | } | |
53 | ||
1a022e3f BO |
54 | /** |
55 | * cpuidle_play_dead - cpu off-lining | |
56 | * | |
ee01e663 | 57 | * Returns in case of an error or no driver |
1a022e3f BO |
58 | */ |
59 | int cpuidle_play_dead(void) | |
60 | { | |
61 | struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); | |
bf4d1b5d | 62 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
8aef33a7 | 63 | int i; |
1a022e3f | 64 | |
ee01e663 TK |
65 | if (!drv) |
66 | return -ENODEV; | |
67 | ||
1a022e3f | 68 | /* Find lowest-power state that supports long-term idle */ |
7d51d979 | 69 | for (i = drv->state_count - 1; i >= 0; i--) |
8aef33a7 DL |
70 | if (drv->states[i].enter_dead) |
71 | return drv->states[i].enter_dead(dev, i); | |
1a022e3f BO |
72 | |
73 | return -ENODEV; | |
74 | } | |
75 | ||
ef2b22ac | 76 | static int find_deepest_state(struct cpuidle_driver *drv, |
0d94039f | 77 | struct cpuidle_device *dev, |
c1d51f68 | 78 | u64 max_latency_ns, |
0d94039f | 79 | unsigned int forbidden_flags, |
28ba086e | 80 | bool s2idle) |
a6220fc1 | 81 | { |
c1d51f68 | 82 | u64 latency_req = 0; |
51164251 | 83 | int i, ret = 0; |
a6220fc1 | 84 | |
51164251 | 85 | for (i = 1; i < drv->state_count; i++) { |
a6220fc1 | 86 | struct cpuidle_state *s = &drv->states[i]; |
a6220fc1 | 87 | |
99e98d3f | 88 | if (dev->states_usage[i].disable || |
c1d51f68 RW |
89 | s->exit_latency_ns <= latency_req || |
90 | s->exit_latency_ns > max_latency_ns || | |
99e98d3f RW |
91 | (s->flags & forbidden_flags) || |
92 | (s2idle && !s->enter_s2idle)) | |
a6220fc1 RW |
93 | continue; |
94 | ||
c1d51f68 | 95 | latency_req = s->exit_latency_ns; |
a6220fc1 RW |
96 | ret = i; |
97 | } | |
98 | return ret; | |
99 | } | |
100 | ||
0e7414b7 | 101 | /** |
c55b51a0 DL |
102 | * cpuidle_use_deepest_state - Set/unset governor override mode. |
103 | * @latency_limit_ns: Idle state exit latency limit (or no override if 0). | |
0e7414b7 | 104 | * |
c55b51a0 DL |
105 | * If @latency_limit_ns is nonzero, set the current CPU to use the deepest idle |
106 | * state with exit latency within @latency_limit_ns (override governors going | |
107 | * forward), or do not override governors if it is zero. | |
0e7414b7 | 108 | */ |
c55b51a0 | 109 | void cpuidle_use_deepest_state(u64 latency_limit_ns) |
bb8313b6 JP |
110 | { |
111 | struct cpuidle_device *dev; | |
112 | ||
113 | preempt_disable(); | |
114 | dev = cpuidle_get_device(); | |
41dc750e | 115 | if (dev) |
c55b51a0 | 116 | dev->forced_idle_latency_limit_ns = latency_limit_ns; |
bb8313b6 JP |
117 | preempt_enable(); |
118 | } | |
119 | ||
ef2b22ac RW |
120 | /** |
121 | * cpuidle_find_deepest_state - Find the deepest available idle state. | |
122 | * @drv: cpuidle driver for the given CPU. | |
123 | * @dev: cpuidle device for the given CPU. | |
124 | */ | |
125 | int cpuidle_find_deepest_state(struct cpuidle_driver *drv, | |
5aa9ba63 DL |
126 | struct cpuidle_device *dev, |
127 | u64 latency_limit_ns) | |
ef2b22ac | 128 | { |
5aa9ba63 | 129 | return find_deepest_state(drv, dev, latency_limit_ns, 0, false); |
ef2b22ac RW |
130 | } |
131 | ||
bb8313b6 | 132 | #ifdef CONFIG_SUSPEND |
28ba086e | 133 | static void enter_s2idle_proper(struct cpuidle_driver *drv, |
124cf911 RW |
134 | struct cpuidle_device *dev, int index) |
135 | { | |
64bdff69 RW |
136 | ktime_t time_start, time_end; |
137 | ||
138 | time_start = ns_to_ktime(local_clock()); | |
139 | ||
ae0afb4f RW |
140 | /* |
141 | * trace_suspend_resume() called by tick_freeze() for the last CPU | |
142 | * executing it contains RCU usage regarded as invalid in the idle | |
143 | * context, so tell RCU about that. | |
144 | */ | |
145 | RCU_NONIDLE(tick_freeze()); | |
124cf911 RW |
146 | /* |
147 | * The state used here cannot be a "coupled" one, because the "coupled" | |
148 | * cpuidle mechanism enables interrupts and doing that with timekeeping | |
149 | * suspended is generally unsafe. | |
150 | */ | |
63caae84 | 151 | stop_critical_timings(); |
28ba086e | 152 | drv->states[index].enter_s2idle(dev, drv, index); |
124cf911 RW |
153 | WARN_ON(!irqs_disabled()); |
154 | /* | |
155 | * timekeeping_resume() that will be called by tick_unfreeze() for the | |
ae0afb4f | 156 | * first CPU executing it calls functions containing RCU read-side |
124cf911 RW |
157 | * critical sections, so tell RCU about that. |
158 | */ | |
159 | RCU_NONIDLE(tick_unfreeze()); | |
63caae84 | 160 | start_critical_timings(); |
64bdff69 RW |
161 | |
162 | time_end = ns_to_ktime(local_clock()); | |
163 | ||
164 | dev->states_usage[index].s2idle_time += ktime_us_delta(time_end, time_start); | |
165 | dev->states_usage[index].s2idle_usage++; | |
124cf911 RW |
166 | } |
167 | ||
38106313 | 168 | /** |
28ba086e | 169 | * cpuidle_enter_s2idle - Enter an idle state suitable for suspend-to-idle. |
ef2b22ac RW |
170 | * @drv: cpuidle driver for the given CPU. |
171 | * @dev: cpuidle device for the given CPU. | |
38106313 | 172 | * |
28ba086e | 173 | * If there are states with the ->enter_s2idle callback, find the deepest of |
ef2b22ac | 174 | * them and enter it with frozen tick. |
38106313 | 175 | */ |
28ba086e | 176 | int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
38106313 | 177 | { |
38106313 RW |
178 | int index; |
179 | ||
124cf911 | 180 | /* |
28ba086e | 181 | * Find the deepest state with ->enter_s2idle present, which guarantees |
124cf911 RW |
182 | * that interrupts won't be enabled when it exits and allows the tick to |
183 | * be frozen safely. | |
184 | */ | |
c1d51f68 | 185 | index = find_deepest_state(drv, dev, U64_MAX, 0, true); |
6f16886b | 186 | if (index > 0) |
28ba086e | 187 | enter_s2idle_proper(drv, dev, index); |
124cf911 | 188 | |
ef2b22ac | 189 | return index; |
38106313 | 190 | } |
87e9b9f1 | 191 | #endif /* CONFIG_SUSPEND */ |
38106313 | 192 | |
56cfbf74 CC |
193 | /** |
194 | * cpuidle_enter_state - enter the state and update stats | |
195 | * @dev: cpuidle device for this cpu | |
196 | * @drv: cpuidle driver for this cpu | |
7312280b | 197 | * @index: index into the states table in @drv of the state to enter |
56cfbf74 CC |
198 | */ |
199 | int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, | |
554c06ba | 200 | int index) |
56cfbf74 CC |
201 | { |
202 | int entered_state; | |
203 | ||
554c06ba | 204 | struct cpuidle_state *target_state = &drv->states[index]; |
df8d9eea | 205 | bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP); |
dbd1b8ea | 206 | ktime_t time_start, time_end; |
554c06ba | 207 | |
df8d9eea RW |
208 | /* |
209 | * Tell the time framework to switch to a broadcast timer because our | |
210 | * local timer will be shut down. If a local timer is used from another | |
211 | * CPU as a broadcast timer, this call may fail if it is not available. | |
212 | */ | |
827a5aef | 213 | if (broadcast && tick_broadcast_enter()) { |
c1d51f68 | 214 | index = find_deepest_state(drv, dev, target_state->exit_latency_ns, |
0d94039f RW |
215 | CPUIDLE_FLAG_TIMER_STOP, false); |
216 | if (index < 0) { | |
217 | default_idle_call(); | |
218 | return -EBUSY; | |
219 | } | |
220 | target_state = &drv->states[index]; | |
f187851b | 221 | broadcast = false; |
827a5aef | 222 | } |
df8d9eea | 223 | |
faad3849 RW |
224 | /* Take note of the planned idle state. */ |
225 | sched_idle_set_state(target_state); | |
226 | ||
30fe6884 | 227 | trace_cpu_idle_rcuidle(index, dev->cpu); |
dbd1b8ea | 228 | time_start = ns_to_ktime(local_clock()); |
554c06ba | 229 | |
63caae84 | 230 | stop_critical_timings(); |
554c06ba | 231 | entered_state = target_state->enter(dev, drv, index); |
63caae84 | 232 | start_critical_timings(); |
554c06ba | 233 | |
f9fccdb9 | 234 | sched_clock_idle_wakeup_event(); |
dbd1b8ea | 235 | time_end = ns_to_ktime(local_clock()); |
30fe6884 | 236 | trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); |
554c06ba | 237 | |
faad3849 RW |
238 | /* The cpu is no longer idle or about to enter idle. */ |
239 | sched_idle_set_state(NULL); | |
240 | ||
df8d9eea RW |
241 | if (broadcast) { |
242 | if (WARN_ON_ONCE(!irqs_disabled())) | |
243 | local_irq_disable(); | |
244 | ||
245 | tick_broadcast_exit(); | |
246 | } | |
247 | ||
e7387da5 | 248 | if (!cpuidle_state_is_coupled(drv, index)) |
0b89e9aa | 249 | local_irq_enable(); |
554c06ba | 250 | |
56cfbf74 | 251 | if (entered_state >= 0) { |
c1d51f68 | 252 | s64 diff, delay = drv->states[entered_state].exit_latency_ns; |
04dab58a RW |
253 | int i; |
254 | ||
7037b43e FL |
255 | /* |
256 | * Update cpuidle counters | |
257 | * This can be moved to within driver enter routine, | |
56cfbf74 CC |
258 | * but that results in multiple copies of same code. |
259 | */ | |
c1d51f68 | 260 | diff = ktime_sub(time_end, time_start); |
7037b43e | 261 | |
c1d51f68 RW |
262 | dev->last_residency_ns = diff; |
263 | dev->states_usage[entered_state].time_ns += diff; | |
56cfbf74 | 264 | dev->states_usage[entered_state].usage++; |
04dab58a | 265 | |
c1d51f68 | 266 | if (diff < drv->states[entered_state].target_residency_ns) { |
04dab58a | 267 | for (i = entered_state - 1; i >= 0; i--) { |
99e98d3f | 268 | if (dev->states_usage[i].disable) |
04dab58a RW |
269 | continue; |
270 | ||
271 | /* Shallower states are enabled, so update. */ | |
272 | dev->states_usage[entered_state].above++; | |
273 | break; | |
274 | } | |
275 | } else if (diff > delay) { | |
276 | for (i = entered_state + 1; i < drv->state_count; i++) { | |
99e98d3f | 277 | if (dev->states_usage[i].disable) |
04dab58a RW |
278 | continue; |
279 | ||
280 | /* | |
281 | * Update if a deeper state would have been a | |
282 | * better match for the observed idle duration. | |
283 | */ | |
c1d51f68 | 284 | if (diff - delay >= drv->states[i].target_residency_ns) |
04dab58a RW |
285 | dev->states_usage[entered_state].below++; |
286 | ||
287 | break; | |
288 | } | |
289 | } | |
56cfbf74 | 290 | } else { |
c1d51f68 | 291 | dev->last_residency_ns = 0; |
56cfbf74 CC |
292 | } |
293 | ||
294 | return entered_state; | |
295 | } | |
296 | ||
4f86d3a8 | 297 | /** |
907e30f1 DL |
298 | * cpuidle_select - ask the cpuidle framework to choose an idle state |
299 | * | |
300 | * @drv: the cpuidle driver | |
301 | * @dev: the cpuidle device | |
45f1ff59 | 302 | * @stop_tick: indication on whether or not to stop the tick |
4f86d3a8 | 303 | * |
51164251 | 304 | * Returns the index of the idle state. The return value must not be negative. |
45f1ff59 RW |
305 | * |
306 | * The memory location pointed to by @stop_tick is expected to be written the | |
307 | * 'false' boolean value if the scheduler tick should not be stopped before | |
308 | * entering the returned state. | |
4f86d3a8 | 309 | */ |
45f1ff59 RW |
310 | int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, |
311 | bool *stop_tick) | |
4f86d3a8 | 312 | { |
45f1ff59 | 313 | return cpuidle_curr_governor->select(drv, dev, stop_tick); |
907e30f1 | 314 | } |
ba8f20c2 | 315 | |
907e30f1 DL |
316 | /** |
317 | * cpuidle_enter - enter into the specified idle state | |
318 | * | |
319 | * @drv: the cpuidle driver tied with the cpu | |
320 | * @dev: the cpuidle device | |
321 | * @index: the index in the idle state table | |
322 | * | |
323 | * Returns the index in the idle state, < 0 in case of error. | |
324 | * The error code depends on the backend driver | |
325 | */ | |
326 | int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, | |
327 | int index) | |
328 | { | |
6f9b83ac UH |
329 | int ret = 0; |
330 | ||
331 | /* | |
332 | * Store the next hrtimer, which becomes either next tick or the next | |
333 | * timer event, whatever expires first. Additionally, to make this data | |
334 | * useful for consumers outside cpuidle, we rely on that the governor's | |
335 | * ->select() callback have decided, whether to stop the tick or not. | |
336 | */ | |
337 | WRITE_ONCE(dev->next_hrtimer, tick_nohz_get_next_hrtimer()); | |
338 | ||
4c1ed5a6 | 339 | if (cpuidle_state_is_coupled(drv, index)) |
6f9b83ac UH |
340 | ret = cpuidle_enter_state_coupled(dev, drv, index); |
341 | else | |
342 | ret = cpuidle_enter_state(dev, drv, index); | |
343 | ||
344 | WRITE_ONCE(dev->next_hrtimer, 0); | |
345 | return ret; | |
907e30f1 | 346 | } |
b60e6a0e | 347 | |
907e30f1 DL |
348 | /** |
349 | * cpuidle_reflect - tell the underlying governor what was the state | |
350 | * we were in | |
351 | * | |
352 | * @dev : the cpuidle device | |
353 | * @index: the index in the idle state table | |
354 | * | |
355 | */ | |
356 | void cpuidle_reflect(struct cpuidle_device *dev, int index) | |
357 | { | |
a802ea96 | 358 | if (cpuidle_curr_governor->reflect && index >= 0) |
907e30f1 | 359 | cpuidle_curr_governor->reflect(dev, index); |
4f86d3a8 LB |
360 | } |
361 | ||
259231a0 MT |
362 | /** |
363 | * cpuidle_poll_time - return amount of time to poll for, | |
364 | * governors can override dev->poll_limit_ns if necessary | |
365 | * | |
366 | * @drv: the cpuidle driver tied with the cpu | |
367 | * @dev: the cpuidle device | |
368 | * | |
369 | */ | |
370 | u64 cpuidle_poll_time(struct cpuidle_driver *drv, | |
371 | struct cpuidle_device *dev) | |
372 | { | |
373 | int i; | |
374 | u64 limit_ns; | |
375 | ||
376 | if (dev->poll_limit_ns) | |
377 | return dev->poll_limit_ns; | |
378 | ||
379 | limit_ns = TICK_NSEC; | |
380 | for (i = 1; i < drv->state_count; i++) { | |
99e98d3f | 381 | if (dev->states_usage[i].disable) |
259231a0 MT |
382 | continue; |
383 | ||
c1d51f68 | 384 | limit_ns = (u64)drv->states[i].target_residency_ns; |
259231a0 MT |
385 | } |
386 | ||
387 | dev->poll_limit_ns = limit_ns; | |
388 | ||
389 | return dev->poll_limit_ns; | |
390 | } | |
391 | ||
4f86d3a8 LB |
392 | /** |
393 | * cpuidle_install_idle_handler - installs the cpuidle idle loop handler | |
394 | */ | |
395 | void cpuidle_install_idle_handler(void) | |
396 | { | |
a0bfa137 | 397 | if (enabled_devices) { |
4f86d3a8 LB |
398 | /* Make sure all changes finished before we switch to new idle */ |
399 | smp_wmb(); | |
a0bfa137 | 400 | initialized = 1; |
4f86d3a8 LB |
401 | } |
402 | } | |
403 | ||
404 | /** | |
405 | * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler | |
406 | */ | |
407 | void cpuidle_uninstall_idle_handler(void) | |
408 | { | |
a0bfa137 LB |
409 | if (enabled_devices) { |
410 | initialized = 0; | |
2ed903c5 | 411 | wake_up_all_idle_cpus(); |
4f86d3a8 | 412 | } |
442bf3aa DL |
413 | |
414 | /* | |
415 | * Make sure external observers (such as the scheduler) | |
416 | * are done looking at pointed idle states. | |
417 | */ | |
418 | synchronize_rcu(); | |
4f86d3a8 LB |
419 | } |
420 | ||
421 | /** | |
422 | * cpuidle_pause_and_lock - temporarily disables CPUIDLE | |
423 | */ | |
424 | void cpuidle_pause_and_lock(void) | |
425 | { | |
426 | mutex_lock(&cpuidle_lock); | |
427 | cpuidle_uninstall_idle_handler(); | |
428 | } | |
429 | ||
430 | EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock); | |
431 | ||
432 | /** | |
433 | * cpuidle_resume_and_unlock - resumes CPUIDLE operation | |
434 | */ | |
435 | void cpuidle_resume_and_unlock(void) | |
436 | { | |
437 | cpuidle_install_idle_handler(); | |
438 | mutex_unlock(&cpuidle_lock); | |
439 | } | |
440 | ||
441 | EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); | |
442 | ||
8651f97b PM |
443 | /* Currently used in suspend/resume path to suspend cpuidle */ |
444 | void cpuidle_pause(void) | |
445 | { | |
446 | mutex_lock(&cpuidle_lock); | |
447 | cpuidle_uninstall_idle_handler(); | |
448 | mutex_unlock(&cpuidle_lock); | |
449 | } | |
450 | ||
451 | /* Currently used in suspend/resume path to resume cpuidle */ | |
452 | void cpuidle_resume(void) | |
453 | { | |
454 | mutex_lock(&cpuidle_lock); | |
455 | cpuidle_install_idle_handler(); | |
456 | mutex_unlock(&cpuidle_lock); | |
457 | } | |
458 | ||
4f86d3a8 LB |
459 | /** |
460 | * cpuidle_enable_device - enables idle PM for a CPU | |
461 | * @dev: the CPU | |
462 | * | |
463 | * This function must be called between cpuidle_pause_and_lock and | |
464 | * cpuidle_resume_and_unlock when used externally. | |
465 | */ | |
466 | int cpuidle_enable_device(struct cpuidle_device *dev) | |
467 | { | |
5df0aa73 | 468 | int ret; |
bf4d1b5d | 469 | struct cpuidle_driver *drv; |
4f86d3a8 | 470 | |
1b0a0e9a SB |
471 | if (!dev) |
472 | return -EINVAL; | |
473 | ||
4f86d3a8 LB |
474 | if (dev->enabled) |
475 | return 0; | |
bf4d1b5d | 476 | |
e7b06a09 GJ |
477 | if (!cpuidle_curr_governor) |
478 | return -EIO; | |
479 | ||
bf4d1b5d DL |
480 | drv = cpuidle_get_cpu_driver(dev); |
481 | ||
e7b06a09 | 482 | if (!drv) |
4f86d3a8 | 483 | return -EIO; |
bf4d1b5d | 484 | |
10b9d3f8 DL |
485 | if (!dev->registered) |
486 | return -EINVAL; | |
487 | ||
bf4d1b5d DL |
488 | ret = cpuidle_add_device_sysfs(dev); |
489 | if (ret) | |
4f86d3a8 LB |
490 | return ret; |
491 | ||
3fc74bd8 GJ |
492 | if (cpuidle_curr_governor->enable) { |
493 | ret = cpuidle_curr_governor->enable(drv, dev); | |
494 | if (ret) | |
495 | goto fail_sysfs; | |
496 | } | |
4f86d3a8 | 497 | |
4f86d3a8 LB |
498 | smp_wmb(); |
499 | ||
500 | dev->enabled = 1; | |
501 | ||
502 | enabled_devices++; | |
503 | return 0; | |
504 | ||
505 | fail_sysfs: | |
bf4d1b5d | 506 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
507 | |
508 | return ret; | |
509 | } | |
510 | ||
511 | EXPORT_SYMBOL_GPL(cpuidle_enable_device); | |
512 | ||
513 | /** | |
514 | * cpuidle_disable_device - disables idle PM for a CPU | |
515 | * @dev: the CPU | |
516 | * | |
517 | * This function must be called between cpuidle_pause_and_lock and | |
518 | * cpuidle_resume_and_unlock when used externally. | |
519 | */ | |
520 | void cpuidle_disable_device(struct cpuidle_device *dev) | |
521 | { | |
bf4d1b5d DL |
522 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
523 | ||
cf31cd1a | 524 | if (!dev || !dev->enabled) |
4f86d3a8 | 525 | return; |
bf4d1b5d DL |
526 | |
527 | if (!drv || !cpuidle_curr_governor) | |
4f86d3a8 LB |
528 | return; |
529 | ||
530 | dev->enabled = 0; | |
531 | ||
532 | if (cpuidle_curr_governor->disable) | |
bf4d1b5d | 533 | cpuidle_curr_governor->disable(drv, dev); |
4f86d3a8 | 534 | |
bf4d1b5d | 535 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
536 | enabled_devices--; |
537 | } | |
538 | ||
539 | EXPORT_SYMBOL_GPL(cpuidle_disable_device); | |
540 | ||
f6bb51a5 DL |
541 | static void __cpuidle_unregister_device(struct cpuidle_device *dev) |
542 | { | |
543 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); | |
544 | ||
545 | list_del(&dev->device_list); | |
546 | per_cpu(cpuidle_devices, dev->cpu) = NULL; | |
547 | module_put(drv->owner); | |
c998c078 DG |
548 | |
549 | dev->registered = 0; | |
f6bb51a5 DL |
550 | } |
551 | ||
267d4bf8 | 552 | static void __cpuidle_device_init(struct cpuidle_device *dev) |
5df0aa73 DL |
553 | { |
554 | memset(dev->states_usage, 0, sizeof(dev->states_usage)); | |
c1d51f68 | 555 | dev->last_residency_ns = 0; |
6f9b83ac | 556 | dev->next_hrtimer = 0; |
5df0aa73 DL |
557 | } |
558 | ||
4f86d3a8 | 559 | /** |
dcb84f33 VP |
560 | * __cpuidle_register_device - internal register function called before register |
561 | * and enable routines | |
4f86d3a8 | 562 | * @dev: the cpu |
dcb84f33 VP |
563 | * |
564 | * cpuidle_lock mutex must be held before this is called | |
4f86d3a8 | 565 | */ |
dcb84f33 | 566 | static int __cpuidle_register_device(struct cpuidle_device *dev) |
4f86d3a8 | 567 | { |
bf4d1b5d | 568 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
99e98d3f | 569 | int i, ret; |
4f86d3a8 | 570 | |
bf4d1b5d | 571 | if (!try_module_get(drv->owner)) |
4f86d3a8 LB |
572 | return -EINVAL; |
573 | ||
99e98d3f RW |
574 | for (i = 0; i < drv->state_count; i++) |
575 | if (drv->states[i].disabled) | |
576 | dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_DRIVER; | |
577 | ||
4f86d3a8 LB |
578 | per_cpu(cpuidle_devices, dev->cpu) = dev; |
579 | list_add(&dev->device_list, &cpuidle_detected_devices); | |
4f86d3a8 | 580 | |
4126c019 | 581 | ret = cpuidle_coupled_register_device(dev); |
47182668 | 582 | if (ret) |
f6bb51a5 | 583 | __cpuidle_unregister_device(dev); |
47182668 VK |
584 | else |
585 | dev->registered = 1; | |
4f86d3a8 | 586 | |
47182668 | 587 | return ret; |
dcb84f33 VP |
588 | } |
589 | ||
590 | /** | |
591 | * cpuidle_register_device - registers a CPU's idle PM feature | |
592 | * @dev: the cpu | |
593 | */ | |
594 | int cpuidle_register_device(struct cpuidle_device *dev) | |
595 | { | |
c878a52d | 596 | int ret = -EBUSY; |
dcb84f33 | 597 | |
1b0a0e9a SB |
598 | if (!dev) |
599 | return -EINVAL; | |
600 | ||
dcb84f33 VP |
601 | mutex_lock(&cpuidle_lock); |
602 | ||
c878a52d DL |
603 | if (dev->registered) |
604 | goto out_unlock; | |
605 | ||
267d4bf8 | 606 | __cpuidle_device_init(dev); |
5df0aa73 | 607 | |
f6bb51a5 DL |
608 | ret = __cpuidle_register_device(dev); |
609 | if (ret) | |
610 | goto out_unlock; | |
611 | ||
612 | ret = cpuidle_add_sysfs(dev); | |
613 | if (ret) | |
614 | goto out_unregister; | |
dcb84f33 | 615 | |
10b9d3f8 | 616 | ret = cpuidle_enable_device(dev); |
f6bb51a5 DL |
617 | if (ret) |
618 | goto out_sysfs; | |
10b9d3f8 | 619 | |
4f86d3a8 LB |
620 | cpuidle_install_idle_handler(); |
621 | ||
f6bb51a5 | 622 | out_unlock: |
4f86d3a8 LB |
623 | mutex_unlock(&cpuidle_lock); |
624 | ||
f6bb51a5 DL |
625 | return ret; |
626 | ||
627 | out_sysfs: | |
628 | cpuidle_remove_sysfs(dev); | |
629 | out_unregister: | |
630 | __cpuidle_unregister_device(dev); | |
631 | goto out_unlock; | |
4f86d3a8 LB |
632 | } |
633 | ||
634 | EXPORT_SYMBOL_GPL(cpuidle_register_device); | |
635 | ||
636 | /** | |
637 | * cpuidle_unregister_device - unregisters a CPU's idle PM feature | |
638 | * @dev: the cpu | |
639 | */ | |
640 | void cpuidle_unregister_device(struct cpuidle_device *dev) | |
641 | { | |
813e8e3d | 642 | if (!dev || dev->registered == 0) |
dcb84f33 VP |
643 | return; |
644 | ||
4f86d3a8 LB |
645 | cpuidle_pause_and_lock(); |
646 | ||
647 | cpuidle_disable_device(dev); | |
648 | ||
1aef40e2 | 649 | cpuidle_remove_sysfs(dev); |
f6bb51a5 DL |
650 | |
651 | __cpuidle_unregister_device(dev); | |
4f86d3a8 | 652 | |
4126c019 CC |
653 | cpuidle_coupled_unregister_device(dev); |
654 | ||
4f86d3a8 | 655 | cpuidle_resume_and_unlock(); |
4f86d3a8 LB |
656 | } |
657 | ||
658 | EXPORT_SYMBOL_GPL(cpuidle_unregister_device); | |
659 | ||
1c192d04 | 660 | /** |
4c637b21 DL |
661 | * cpuidle_unregister: unregister a driver and the devices. This function |
662 | * can be used only if the driver has been previously registered through | |
663 | * the cpuidle_register function. | |
664 | * | |
665 | * @drv: a valid pointer to a struct cpuidle_driver | |
666 | */ | |
667 | void cpuidle_unregister(struct cpuidle_driver *drv) | |
668 | { | |
669 | int cpu; | |
670 | struct cpuidle_device *device; | |
671 | ||
82467a5a | 672 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
673 | device = &per_cpu(cpuidle_dev, cpu); |
674 | cpuidle_unregister_device(device); | |
675 | } | |
676 | ||
677 | cpuidle_unregister_driver(drv); | |
678 | } | |
679 | EXPORT_SYMBOL_GPL(cpuidle_unregister); | |
680 | ||
681 | /** | |
682 | * cpuidle_register: registers the driver and the cpu devices with the | |
683 | * coupled_cpus passed as parameter. This function is used for all common | |
684 | * initialization pattern there are in the arch specific drivers. The | |
685 | * devices is globally defined in this file. | |
686 | * | |
687 | * @drv : a valid pointer to a struct cpuidle_driver | |
688 | * @coupled_cpus: a cpumask for the coupled states | |
689 | * | |
690 | * Returns 0 on success, < 0 otherwise | |
691 | */ | |
692 | int cpuidle_register(struct cpuidle_driver *drv, | |
693 | const struct cpumask *const coupled_cpus) | |
694 | { | |
695 | int ret, cpu; | |
696 | struct cpuidle_device *device; | |
697 | ||
698 | ret = cpuidle_register_driver(drv); | |
699 | if (ret) { | |
700 | pr_err("failed to register cpuidle driver\n"); | |
701 | return ret; | |
702 | } | |
703 | ||
82467a5a | 704 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
705 | device = &per_cpu(cpuidle_dev, cpu); |
706 | device->cpu = cpu; | |
707 | ||
708 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED | |
709 | /* | |
caf4a36e | 710 | * On multiplatform for ARM, the coupled idle states could be |
4c637b21 DL |
711 | * enabled in the kernel even if the cpuidle driver does not |
712 | * use it. Note, coupled_cpus is a struct copy. | |
713 | */ | |
714 | if (coupled_cpus) | |
715 | device->coupled_cpus = *coupled_cpus; | |
716 | #endif | |
717 | ret = cpuidle_register_device(device); | |
718 | if (!ret) | |
719 | continue; | |
720 | ||
721 | pr_err("Failed to register cpuidle device for cpu%d\n", cpu); | |
722 | ||
723 | cpuidle_unregister(drv); | |
724 | break; | |
725 | } | |
726 | ||
727 | return ret; | |
728 | } | |
729 | EXPORT_SYMBOL_GPL(cpuidle_register); | |
730 | ||
4f86d3a8 LB |
731 | #ifdef CONFIG_SMP |
732 | ||
4f86d3a8 LB |
733 | /* |
734 | * This function gets called when a part of the kernel has a new latency | |
735 | * requirement. This means we need to get all processors out of their C-state, | |
736 | * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that | |
737 | * wakes them all right up. | |
738 | */ | |
739 | static int cpuidle_latency_notify(struct notifier_block *b, | |
740 | unsigned long l, void *v) | |
741 | { | |
2ed903c5 | 742 | wake_up_all_idle_cpus(); |
4f86d3a8 LB |
743 | return NOTIFY_OK; |
744 | } | |
745 | ||
746 | static struct notifier_block cpuidle_latency_notifier = { | |
747 | .notifier_call = cpuidle_latency_notify, | |
748 | }; | |
749 | ||
d82b3518 MG |
750 | static inline void latency_notifier_init(struct notifier_block *n) |
751 | { | |
752 | pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n); | |
753 | } | |
4f86d3a8 LB |
754 | |
755 | #else /* CONFIG_SMP */ | |
756 | ||
757 | #define latency_notifier_init(x) do { } while (0) | |
758 | ||
759 | #endif /* CONFIG_SMP */ | |
760 | ||
761 | /** | |
762 | * cpuidle_init - core initializer | |
763 | */ | |
764 | static int __init cpuidle_init(void) | |
765 | { | |
766 | int ret; | |
767 | ||
62027aea LB |
768 | if (cpuidle_disabled()) |
769 | return -ENODEV; | |
770 | ||
8a25a2fd | 771 | ret = cpuidle_add_interface(cpu_subsys.dev_root); |
4f86d3a8 LB |
772 | if (ret) |
773 | return ret; | |
774 | ||
775 | latency_notifier_init(&cpuidle_latency_notifier); | |
776 | ||
777 | return 0; | |
778 | } | |
779 | ||
62027aea | 780 | module_param(off, int, 0444); |
61cb5758 | 781 | module_param_string(governor, param_governor, CPUIDLE_NAME_LEN, 0444); |
4f86d3a8 | 782 | core_initcall(cpuidle_init); |