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> |
bf9282dc | 25 | #include <linux/mmu_context.h> |
288f023e | 26 | #include <trace/events/power.h> |
4f86d3a8 LB |
27 | |
28 | #include "cpuidle.h" | |
29 | ||
30 | DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices); | |
4c637b21 | 31 | DEFINE_PER_CPU(struct cpuidle_device, cpuidle_dev); |
4f86d3a8 LB |
32 | |
33 | DEFINE_MUTEX(cpuidle_lock); | |
34 | LIST_HEAD(cpuidle_detected_devices); | |
4f86d3a8 LB |
35 | |
36 | static int enabled_devices; | |
62027aea | 37 | static int off __read_mostly; |
a0bfa137 | 38 | static int initialized __read_mostly; |
62027aea LB |
39 | |
40 | int cpuidle_disabled(void) | |
41 | { | |
42 | return off; | |
43 | } | |
d91ee586 LB |
44 | void disable_cpuidle(void) |
45 | { | |
46 | off = 1; | |
47 | } | |
4f86d3a8 | 48 | |
ef2b22ac RW |
49 | bool cpuidle_not_available(struct cpuidle_driver *drv, |
50 | struct cpuidle_device *dev) | |
31a34090 RW |
51 | { |
52 | return off || !initialized || !drv || !dev || !dev->enabled; | |
53 | } | |
54 | ||
1a022e3f BO |
55 | /** |
56 | * cpuidle_play_dead - cpu off-lining | |
57 | * | |
ee01e663 | 58 | * Returns in case of an error or no driver |
1a022e3f BO |
59 | */ |
60 | int cpuidle_play_dead(void) | |
61 | { | |
62 | struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); | |
bf4d1b5d | 63 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
8aef33a7 | 64 | int i; |
1a022e3f | 65 | |
ee01e663 TK |
66 | if (!drv) |
67 | return -ENODEV; | |
68 | ||
1a022e3f | 69 | /* Find lowest-power state that supports long-term idle */ |
7d51d979 | 70 | for (i = drv->state_count - 1; i >= 0; i--) |
8aef33a7 DL |
71 | if (drv->states[i].enter_dead) |
72 | return drv->states[i].enter_dead(dev, i); | |
1a022e3f BO |
73 | |
74 | return -ENODEV; | |
75 | } | |
76 | ||
ef2b22ac | 77 | static int find_deepest_state(struct cpuidle_driver *drv, |
0d94039f | 78 | struct cpuidle_device *dev, |
c1d51f68 | 79 | u64 max_latency_ns, |
0d94039f | 80 | unsigned int forbidden_flags, |
28ba086e | 81 | bool s2idle) |
a6220fc1 | 82 | { |
c1d51f68 | 83 | u64 latency_req = 0; |
51164251 | 84 | int i, ret = 0; |
a6220fc1 | 85 | |
51164251 | 86 | for (i = 1; i < drv->state_count; i++) { |
a6220fc1 | 87 | struct cpuidle_state *s = &drv->states[i]; |
a6220fc1 | 88 | |
99e98d3f | 89 | if (dev->states_usage[i].disable || |
c1d51f68 RW |
90 | s->exit_latency_ns <= latency_req || |
91 | s->exit_latency_ns > max_latency_ns || | |
99e98d3f RW |
92 | (s->flags & forbidden_flags) || |
93 | (s2idle && !s->enter_s2idle)) | |
a6220fc1 RW |
94 | continue; |
95 | ||
c1d51f68 | 96 | latency_req = s->exit_latency_ns; |
a6220fc1 RW |
97 | ret = i; |
98 | } | |
99 | return ret; | |
100 | } | |
101 | ||
0e7414b7 | 102 | /** |
c55b51a0 DL |
103 | * cpuidle_use_deepest_state - Set/unset governor override mode. |
104 | * @latency_limit_ns: Idle state exit latency limit (or no override if 0). | |
0e7414b7 | 105 | * |
c55b51a0 DL |
106 | * If @latency_limit_ns is nonzero, set the current CPU to use the deepest idle |
107 | * state with exit latency within @latency_limit_ns (override governors going | |
108 | * forward), or do not override governors if it is zero. | |
0e7414b7 | 109 | */ |
c55b51a0 | 110 | void cpuidle_use_deepest_state(u64 latency_limit_ns) |
bb8313b6 JP |
111 | { |
112 | struct cpuidle_device *dev; | |
113 | ||
114 | preempt_disable(); | |
115 | dev = cpuidle_get_device(); | |
41dc750e | 116 | if (dev) |
c55b51a0 | 117 | dev->forced_idle_latency_limit_ns = latency_limit_ns; |
bb8313b6 JP |
118 | preempt_enable(); |
119 | } | |
120 | ||
ef2b22ac RW |
121 | /** |
122 | * cpuidle_find_deepest_state - Find the deepest available idle state. | |
123 | * @drv: cpuidle driver for the given CPU. | |
124 | * @dev: cpuidle device for the given CPU. | |
cefb9409 BG |
125 | * @latency_limit_ns: Idle state exit latency limit |
126 | * | |
127 | * Return: the index of the deepest available idle state. | |
ef2b22ac RW |
128 | */ |
129 | int cpuidle_find_deepest_state(struct cpuidle_driver *drv, | |
5aa9ba63 DL |
130 | struct cpuidle_device *dev, |
131 | u64 latency_limit_ns) | |
ef2b22ac | 132 | { |
5aa9ba63 | 133 | return find_deepest_state(drv, dev, latency_limit_ns, 0, false); |
ef2b22ac RW |
134 | } |
135 | ||
bb8313b6 | 136 | #ifdef CONFIG_SUSPEND |
28ba086e | 137 | static void enter_s2idle_proper(struct cpuidle_driver *drv, |
124cf911 RW |
138 | struct cpuidle_device *dev, int index) |
139 | { | |
64bdff69 | 140 | ktime_t time_start, time_end; |
8747f202 | 141 | struct cpuidle_state *target_state = &drv->states[index]; |
64bdff69 RW |
142 | |
143 | time_start = ns_to_ktime(local_clock()); | |
144 | ||
1098582a | 145 | 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(); |
8747f202 PZ |
152 | if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) |
153 | rcu_idle_enter(); | |
154 | target_state->enter_s2idle(dev, drv, index); | |
49d9c593 PZ |
155 | if (WARN_ON_ONCE(!irqs_disabled())) |
156 | local_irq_disable(); | |
8747f202 PZ |
157 | if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) |
158 | rcu_idle_exit(); | |
1098582a | 159 | 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); |
10e8b11e | 186 | if (index > 0) { |
28ba086e | 187 | enter_s2idle_proper(drv, dev, index); |
10e8b11e RW |
188 | local_irq_enable(); |
189 | } | |
ef2b22ac | 190 | return index; |
38106313 | 191 | } |
87e9b9f1 | 192 | #endif /* CONFIG_SUSPEND */ |
38106313 | 193 | |
56cfbf74 CC |
194 | /** |
195 | * cpuidle_enter_state - enter the state and update stats | |
196 | * @dev: cpuidle device for this cpu | |
197 | * @drv: cpuidle driver for this cpu | |
7312280b | 198 | * @index: index into the states table in @drv of the state to enter |
56cfbf74 CC |
199 | */ |
200 | int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, | |
554c06ba | 201 | int index) |
56cfbf74 CC |
202 | { |
203 | int entered_state; | |
204 | ||
554c06ba | 205 | struct cpuidle_state *target_state = &drv->states[index]; |
df8d9eea | 206 | bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP); |
dbd1b8ea | 207 | ktime_t time_start, time_end; |
554c06ba | 208 | |
df8d9eea RW |
209 | /* |
210 | * Tell the time framework to switch to a broadcast timer because our | |
211 | * local timer will be shut down. If a local timer is used from another | |
212 | * CPU as a broadcast timer, this call may fail if it is not available. | |
213 | */ | |
827a5aef | 214 | if (broadcast && tick_broadcast_enter()) { |
c1d51f68 | 215 | index = find_deepest_state(drv, dev, target_state->exit_latency_ns, |
0d94039f RW |
216 | CPUIDLE_FLAG_TIMER_STOP, false); |
217 | if (index < 0) { | |
218 | default_idle_call(); | |
219 | return -EBUSY; | |
220 | } | |
221 | target_state = &drv->states[index]; | |
f187851b | 222 | broadcast = false; |
827a5aef | 223 | } |
df8d9eea | 224 | |
bf9282dc PZ |
225 | if (target_state->flags & CPUIDLE_FLAG_TLB_FLUSHED) |
226 | leave_mm(dev->cpu); | |
227 | ||
faad3849 RW |
228 | /* Take note of the planned idle state. */ |
229 | sched_idle_set_state(target_state); | |
230 | ||
1098582a | 231 | trace_cpu_idle(index, dev->cpu); |
dbd1b8ea | 232 | time_start = ns_to_ktime(local_clock()); |
554c06ba | 233 | |
63caae84 | 234 | stop_critical_timings(); |
8747f202 PZ |
235 | if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) |
236 | rcu_idle_enter(); | |
554c06ba | 237 | entered_state = target_state->enter(dev, drv, index); |
8747f202 PZ |
238 | if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) |
239 | rcu_idle_exit(); | |
63caae84 | 240 | start_critical_timings(); |
554c06ba | 241 | |
f9fccdb9 | 242 | sched_clock_idle_wakeup_event(); |
dbd1b8ea | 243 | time_end = ns_to_ktime(local_clock()); |
1098582a | 244 | trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu); |
554c06ba | 245 | |
faad3849 RW |
246 | /* The cpu is no longer idle or about to enter idle. */ |
247 | sched_idle_set_state(NULL); | |
248 | ||
df8d9eea RW |
249 | if (broadcast) { |
250 | if (WARN_ON_ONCE(!irqs_disabled())) | |
251 | local_irq_disable(); | |
252 | ||
253 | tick_broadcast_exit(); | |
254 | } | |
255 | ||
e7387da5 | 256 | if (!cpuidle_state_is_coupled(drv, index)) |
0b89e9aa | 257 | local_irq_enable(); |
554c06ba | 258 | |
56cfbf74 | 259 | if (entered_state >= 0) { |
c1d51f68 | 260 | s64 diff, delay = drv->states[entered_state].exit_latency_ns; |
04dab58a RW |
261 | int i; |
262 | ||
7037b43e FL |
263 | /* |
264 | * Update cpuidle counters | |
265 | * This can be moved to within driver enter routine, | |
56cfbf74 CC |
266 | * but that results in multiple copies of same code. |
267 | */ | |
c1d51f68 | 268 | diff = ktime_sub(time_end, time_start); |
7037b43e | 269 | |
c1d51f68 RW |
270 | dev->last_residency_ns = diff; |
271 | dev->states_usage[entered_state].time_ns += diff; | |
56cfbf74 | 272 | dev->states_usage[entered_state].usage++; |
04dab58a | 273 | |
c1d51f68 | 274 | if (diff < drv->states[entered_state].target_residency_ns) { |
04dab58a | 275 | for (i = entered_state - 1; i >= 0; i--) { |
99e98d3f | 276 | if (dev->states_usage[i].disable) |
04dab58a RW |
277 | continue; |
278 | ||
279 | /* Shallower states are enabled, so update. */ | |
280 | dev->states_usage[entered_state].above++; | |
281 | break; | |
282 | } | |
283 | } else if (diff > delay) { | |
284 | for (i = entered_state + 1; i < drv->state_count; i++) { | |
99e98d3f | 285 | if (dev->states_usage[i].disable) |
04dab58a RW |
286 | continue; |
287 | ||
288 | /* | |
289 | * Update if a deeper state would have been a | |
290 | * better match for the observed idle duration. | |
291 | */ | |
c1d51f68 | 292 | if (diff - delay >= drv->states[i].target_residency_ns) |
04dab58a RW |
293 | dev->states_usage[entered_state].below++; |
294 | ||
295 | break; | |
296 | } | |
297 | } | |
56cfbf74 | 298 | } else { |
c1d51f68 | 299 | dev->last_residency_ns = 0; |
f49735f4 | 300 | dev->states_usage[index].rejected++; |
56cfbf74 CC |
301 | } |
302 | ||
303 | return entered_state; | |
304 | } | |
305 | ||
4f86d3a8 | 306 | /** |
907e30f1 DL |
307 | * cpuidle_select - ask the cpuidle framework to choose an idle state |
308 | * | |
309 | * @drv: the cpuidle driver | |
310 | * @dev: the cpuidle device | |
45f1ff59 | 311 | * @stop_tick: indication on whether or not to stop the tick |
4f86d3a8 | 312 | * |
51164251 | 313 | * Returns the index of the idle state. The return value must not be negative. |
45f1ff59 RW |
314 | * |
315 | * The memory location pointed to by @stop_tick is expected to be written the | |
316 | * 'false' boolean value if the scheduler tick should not be stopped before | |
317 | * entering the returned state. | |
4f86d3a8 | 318 | */ |
45f1ff59 RW |
319 | int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, |
320 | bool *stop_tick) | |
4f86d3a8 | 321 | { |
45f1ff59 | 322 | return cpuidle_curr_governor->select(drv, dev, stop_tick); |
907e30f1 | 323 | } |
ba8f20c2 | 324 | |
907e30f1 DL |
325 | /** |
326 | * cpuidle_enter - enter into the specified idle state | |
327 | * | |
328 | * @drv: the cpuidle driver tied with the cpu | |
329 | * @dev: the cpuidle device | |
330 | * @index: the index in the idle state table | |
331 | * | |
332 | * Returns the index in the idle state, < 0 in case of error. | |
333 | * The error code depends on the backend driver | |
334 | */ | |
335 | int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, | |
336 | int index) | |
337 | { | |
6f9b83ac UH |
338 | int ret = 0; |
339 | ||
340 | /* | |
341 | * Store the next hrtimer, which becomes either next tick or the next | |
342 | * timer event, whatever expires first. Additionally, to make this data | |
343 | * useful for consumers outside cpuidle, we rely on that the governor's | |
344 | * ->select() callback have decided, whether to stop the tick or not. | |
345 | */ | |
346 | WRITE_ONCE(dev->next_hrtimer, tick_nohz_get_next_hrtimer()); | |
347 | ||
4c1ed5a6 | 348 | if (cpuidle_state_is_coupled(drv, index)) |
6f9b83ac UH |
349 | ret = cpuidle_enter_state_coupled(dev, drv, index); |
350 | else | |
351 | ret = cpuidle_enter_state(dev, drv, index); | |
352 | ||
353 | WRITE_ONCE(dev->next_hrtimer, 0); | |
354 | return ret; | |
907e30f1 | 355 | } |
b60e6a0e | 356 | |
907e30f1 DL |
357 | /** |
358 | * cpuidle_reflect - tell the underlying governor what was the state | |
359 | * we were in | |
360 | * | |
361 | * @dev : the cpuidle device | |
362 | * @index: the index in the idle state table | |
363 | * | |
364 | */ | |
365 | void cpuidle_reflect(struct cpuidle_device *dev, int index) | |
366 | { | |
a802ea96 | 367 | if (cpuidle_curr_governor->reflect && index >= 0) |
907e30f1 | 368 | cpuidle_curr_governor->reflect(dev, index); |
4f86d3a8 LB |
369 | } |
370 | ||
259231a0 MT |
371 | /** |
372 | * cpuidle_poll_time - return amount of time to poll for, | |
373 | * governors can override dev->poll_limit_ns if necessary | |
374 | * | |
375 | * @drv: the cpuidle driver tied with the cpu | |
376 | * @dev: the cpuidle device | |
377 | * | |
378 | */ | |
379 | u64 cpuidle_poll_time(struct cpuidle_driver *drv, | |
380 | struct cpuidle_device *dev) | |
381 | { | |
382 | int i; | |
383 | u64 limit_ns; | |
384 | ||
385 | if (dev->poll_limit_ns) | |
386 | return dev->poll_limit_ns; | |
387 | ||
388 | limit_ns = TICK_NSEC; | |
389 | for (i = 1; i < drv->state_count; i++) { | |
99e98d3f | 390 | if (dev->states_usage[i].disable) |
259231a0 MT |
391 | continue; |
392 | ||
d4d81401 | 393 | limit_ns = drv->states[i].target_residency_ns; |
36fcb429 | 394 | break; |
259231a0 MT |
395 | } |
396 | ||
397 | dev->poll_limit_ns = limit_ns; | |
398 | ||
399 | return dev->poll_limit_ns; | |
400 | } | |
401 | ||
4f86d3a8 LB |
402 | /** |
403 | * cpuidle_install_idle_handler - installs the cpuidle idle loop handler | |
404 | */ | |
405 | void cpuidle_install_idle_handler(void) | |
406 | { | |
a0bfa137 | 407 | if (enabled_devices) { |
4f86d3a8 LB |
408 | /* Make sure all changes finished before we switch to new idle */ |
409 | smp_wmb(); | |
a0bfa137 | 410 | initialized = 1; |
4f86d3a8 LB |
411 | } |
412 | } | |
413 | ||
414 | /** | |
415 | * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler | |
416 | */ | |
417 | void cpuidle_uninstall_idle_handler(void) | |
418 | { | |
a0bfa137 LB |
419 | if (enabled_devices) { |
420 | initialized = 0; | |
2ed903c5 | 421 | wake_up_all_idle_cpus(); |
4f86d3a8 | 422 | } |
442bf3aa DL |
423 | |
424 | /* | |
425 | * Make sure external observers (such as the scheduler) | |
426 | * are done looking at pointed idle states. | |
427 | */ | |
428 | synchronize_rcu(); | |
4f86d3a8 LB |
429 | } |
430 | ||
431 | /** | |
432 | * cpuidle_pause_and_lock - temporarily disables CPUIDLE | |
433 | */ | |
434 | void cpuidle_pause_and_lock(void) | |
435 | { | |
436 | mutex_lock(&cpuidle_lock); | |
437 | cpuidle_uninstall_idle_handler(); | |
438 | } | |
439 | ||
440 | EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock); | |
441 | ||
442 | /** | |
443 | * cpuidle_resume_and_unlock - resumes CPUIDLE operation | |
444 | */ | |
445 | void cpuidle_resume_and_unlock(void) | |
446 | { | |
447 | cpuidle_install_idle_handler(); | |
448 | mutex_unlock(&cpuidle_lock); | |
449 | } | |
450 | ||
451 | EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); | |
452 | ||
8651f97b PM |
453 | /* Currently used in suspend/resume path to suspend cpuidle */ |
454 | void cpuidle_pause(void) | |
455 | { | |
456 | mutex_lock(&cpuidle_lock); | |
457 | cpuidle_uninstall_idle_handler(); | |
458 | mutex_unlock(&cpuidle_lock); | |
459 | } | |
460 | ||
461 | /* Currently used in suspend/resume path to resume cpuidle */ | |
462 | void cpuidle_resume(void) | |
463 | { | |
464 | mutex_lock(&cpuidle_lock); | |
465 | cpuidle_install_idle_handler(); | |
466 | mutex_unlock(&cpuidle_lock); | |
467 | } | |
468 | ||
4f86d3a8 LB |
469 | /** |
470 | * cpuidle_enable_device - enables idle PM for a CPU | |
471 | * @dev: the CPU | |
472 | * | |
473 | * This function must be called between cpuidle_pause_and_lock and | |
474 | * cpuidle_resume_and_unlock when used externally. | |
475 | */ | |
476 | int cpuidle_enable_device(struct cpuidle_device *dev) | |
477 | { | |
5df0aa73 | 478 | int ret; |
bf4d1b5d | 479 | struct cpuidle_driver *drv; |
4f86d3a8 | 480 | |
1b0a0e9a SB |
481 | if (!dev) |
482 | return -EINVAL; | |
483 | ||
4f86d3a8 LB |
484 | if (dev->enabled) |
485 | return 0; | |
bf4d1b5d | 486 | |
e7b06a09 GJ |
487 | if (!cpuidle_curr_governor) |
488 | return -EIO; | |
489 | ||
bf4d1b5d DL |
490 | drv = cpuidle_get_cpu_driver(dev); |
491 | ||
e7b06a09 | 492 | if (!drv) |
4f86d3a8 | 493 | return -EIO; |
bf4d1b5d | 494 | |
10b9d3f8 DL |
495 | if (!dev->registered) |
496 | return -EINVAL; | |
497 | ||
bf4d1b5d DL |
498 | ret = cpuidle_add_device_sysfs(dev); |
499 | if (ret) | |
4f86d3a8 LB |
500 | return ret; |
501 | ||
3fc74bd8 GJ |
502 | if (cpuidle_curr_governor->enable) { |
503 | ret = cpuidle_curr_governor->enable(drv, dev); | |
504 | if (ret) | |
505 | goto fail_sysfs; | |
506 | } | |
4f86d3a8 | 507 | |
4f86d3a8 LB |
508 | smp_wmb(); |
509 | ||
510 | dev->enabled = 1; | |
511 | ||
512 | enabled_devices++; | |
513 | return 0; | |
514 | ||
515 | fail_sysfs: | |
bf4d1b5d | 516 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
517 | |
518 | return ret; | |
519 | } | |
520 | ||
521 | EXPORT_SYMBOL_GPL(cpuidle_enable_device); | |
522 | ||
523 | /** | |
524 | * cpuidle_disable_device - disables idle PM for a CPU | |
525 | * @dev: the CPU | |
526 | * | |
527 | * This function must be called between cpuidle_pause_and_lock and | |
528 | * cpuidle_resume_and_unlock when used externally. | |
529 | */ | |
530 | void cpuidle_disable_device(struct cpuidle_device *dev) | |
531 | { | |
bf4d1b5d DL |
532 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
533 | ||
cf31cd1a | 534 | if (!dev || !dev->enabled) |
4f86d3a8 | 535 | return; |
bf4d1b5d DL |
536 | |
537 | if (!drv || !cpuidle_curr_governor) | |
4f86d3a8 LB |
538 | return; |
539 | ||
540 | dev->enabled = 0; | |
541 | ||
542 | if (cpuidle_curr_governor->disable) | |
bf4d1b5d | 543 | cpuidle_curr_governor->disable(drv, dev); |
4f86d3a8 | 544 | |
bf4d1b5d | 545 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
546 | enabled_devices--; |
547 | } | |
548 | ||
549 | EXPORT_SYMBOL_GPL(cpuidle_disable_device); | |
550 | ||
f6bb51a5 DL |
551 | static void __cpuidle_unregister_device(struct cpuidle_device *dev) |
552 | { | |
553 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); | |
554 | ||
555 | list_del(&dev->device_list); | |
556 | per_cpu(cpuidle_devices, dev->cpu) = NULL; | |
557 | module_put(drv->owner); | |
c998c078 DG |
558 | |
559 | dev->registered = 0; | |
f6bb51a5 DL |
560 | } |
561 | ||
267d4bf8 | 562 | static void __cpuidle_device_init(struct cpuidle_device *dev) |
5df0aa73 DL |
563 | { |
564 | memset(dev->states_usage, 0, sizeof(dev->states_usage)); | |
c1d51f68 | 565 | dev->last_residency_ns = 0; |
6f9b83ac | 566 | dev->next_hrtimer = 0; |
5df0aa73 DL |
567 | } |
568 | ||
4f86d3a8 | 569 | /** |
dcb84f33 VP |
570 | * __cpuidle_register_device - internal register function called before register |
571 | * and enable routines | |
4f86d3a8 | 572 | * @dev: the cpu |
dcb84f33 VP |
573 | * |
574 | * cpuidle_lock mutex must be held before this is called | |
4f86d3a8 | 575 | */ |
dcb84f33 | 576 | static int __cpuidle_register_device(struct cpuidle_device *dev) |
4f86d3a8 | 577 | { |
bf4d1b5d | 578 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
99e98d3f | 579 | int i, ret; |
4f86d3a8 | 580 | |
bf4d1b5d | 581 | if (!try_module_get(drv->owner)) |
4f86d3a8 LB |
582 | return -EINVAL; |
583 | ||
75a80267 | 584 | for (i = 0; i < drv->state_count; i++) { |
ba1e78a1 | 585 | if (drv->states[i].flags & CPUIDLE_FLAG_UNUSABLE) |
99e98d3f RW |
586 | dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_DRIVER; |
587 | ||
75a80267 RW |
588 | if (drv->states[i].flags & CPUIDLE_FLAG_OFF) |
589 | dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_USER; | |
590 | } | |
591 | ||
4f86d3a8 LB |
592 | per_cpu(cpuidle_devices, dev->cpu) = dev; |
593 | list_add(&dev->device_list, &cpuidle_detected_devices); | |
4f86d3a8 | 594 | |
4126c019 | 595 | ret = cpuidle_coupled_register_device(dev); |
47182668 | 596 | if (ret) |
f6bb51a5 | 597 | __cpuidle_unregister_device(dev); |
47182668 VK |
598 | else |
599 | dev->registered = 1; | |
4f86d3a8 | 600 | |
47182668 | 601 | return ret; |
dcb84f33 VP |
602 | } |
603 | ||
604 | /** | |
605 | * cpuidle_register_device - registers a CPU's idle PM feature | |
606 | * @dev: the cpu | |
607 | */ | |
608 | int cpuidle_register_device(struct cpuidle_device *dev) | |
609 | { | |
c878a52d | 610 | int ret = -EBUSY; |
dcb84f33 | 611 | |
1b0a0e9a SB |
612 | if (!dev) |
613 | return -EINVAL; | |
614 | ||
dcb84f33 VP |
615 | mutex_lock(&cpuidle_lock); |
616 | ||
c878a52d DL |
617 | if (dev->registered) |
618 | goto out_unlock; | |
619 | ||
267d4bf8 | 620 | __cpuidle_device_init(dev); |
5df0aa73 | 621 | |
f6bb51a5 DL |
622 | ret = __cpuidle_register_device(dev); |
623 | if (ret) | |
624 | goto out_unlock; | |
625 | ||
626 | ret = cpuidle_add_sysfs(dev); | |
627 | if (ret) | |
628 | goto out_unregister; | |
dcb84f33 | 629 | |
10b9d3f8 | 630 | ret = cpuidle_enable_device(dev); |
f6bb51a5 DL |
631 | if (ret) |
632 | goto out_sysfs; | |
10b9d3f8 | 633 | |
4f86d3a8 LB |
634 | cpuidle_install_idle_handler(); |
635 | ||
f6bb51a5 | 636 | out_unlock: |
4f86d3a8 LB |
637 | mutex_unlock(&cpuidle_lock); |
638 | ||
f6bb51a5 DL |
639 | return ret; |
640 | ||
641 | out_sysfs: | |
642 | cpuidle_remove_sysfs(dev); | |
643 | out_unregister: | |
644 | __cpuidle_unregister_device(dev); | |
645 | goto out_unlock; | |
4f86d3a8 LB |
646 | } |
647 | ||
648 | EXPORT_SYMBOL_GPL(cpuidle_register_device); | |
649 | ||
650 | /** | |
651 | * cpuidle_unregister_device - unregisters a CPU's idle PM feature | |
652 | * @dev: the cpu | |
653 | */ | |
654 | void cpuidle_unregister_device(struct cpuidle_device *dev) | |
655 | { | |
813e8e3d | 656 | if (!dev || dev->registered == 0) |
dcb84f33 VP |
657 | return; |
658 | ||
4f86d3a8 LB |
659 | cpuidle_pause_and_lock(); |
660 | ||
661 | cpuidle_disable_device(dev); | |
662 | ||
1aef40e2 | 663 | cpuidle_remove_sysfs(dev); |
f6bb51a5 DL |
664 | |
665 | __cpuidle_unregister_device(dev); | |
4f86d3a8 | 666 | |
4126c019 CC |
667 | cpuidle_coupled_unregister_device(dev); |
668 | ||
4f86d3a8 | 669 | cpuidle_resume_and_unlock(); |
4f86d3a8 LB |
670 | } |
671 | ||
672 | EXPORT_SYMBOL_GPL(cpuidle_unregister_device); | |
673 | ||
1c192d04 | 674 | /** |
4c637b21 DL |
675 | * cpuidle_unregister: unregister a driver and the devices. This function |
676 | * can be used only if the driver has been previously registered through | |
677 | * the cpuidle_register function. | |
678 | * | |
679 | * @drv: a valid pointer to a struct cpuidle_driver | |
680 | */ | |
681 | void cpuidle_unregister(struct cpuidle_driver *drv) | |
682 | { | |
683 | int cpu; | |
684 | struct cpuidle_device *device; | |
685 | ||
82467a5a | 686 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
687 | device = &per_cpu(cpuidle_dev, cpu); |
688 | cpuidle_unregister_device(device); | |
689 | } | |
690 | ||
691 | cpuidle_unregister_driver(drv); | |
692 | } | |
693 | EXPORT_SYMBOL_GPL(cpuidle_unregister); | |
694 | ||
695 | /** | |
696 | * cpuidle_register: registers the driver and the cpu devices with the | |
697 | * coupled_cpus passed as parameter. This function is used for all common | |
698 | * initialization pattern there are in the arch specific drivers. The | |
699 | * devices is globally defined in this file. | |
700 | * | |
701 | * @drv : a valid pointer to a struct cpuidle_driver | |
702 | * @coupled_cpus: a cpumask for the coupled states | |
703 | * | |
704 | * Returns 0 on success, < 0 otherwise | |
705 | */ | |
706 | int cpuidle_register(struct cpuidle_driver *drv, | |
707 | const struct cpumask *const coupled_cpus) | |
708 | { | |
709 | int ret, cpu; | |
710 | struct cpuidle_device *device; | |
711 | ||
712 | ret = cpuidle_register_driver(drv); | |
713 | if (ret) { | |
714 | pr_err("failed to register cpuidle driver\n"); | |
715 | return ret; | |
716 | } | |
717 | ||
82467a5a | 718 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
719 | device = &per_cpu(cpuidle_dev, cpu); |
720 | device->cpu = cpu; | |
721 | ||
722 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED | |
723 | /* | |
caf4a36e | 724 | * On multiplatform for ARM, the coupled idle states could be |
4c637b21 DL |
725 | * enabled in the kernel even if the cpuidle driver does not |
726 | * use it. Note, coupled_cpus is a struct copy. | |
727 | */ | |
728 | if (coupled_cpus) | |
729 | device->coupled_cpus = *coupled_cpus; | |
730 | #endif | |
731 | ret = cpuidle_register_device(device); | |
732 | if (!ret) | |
733 | continue; | |
734 | ||
735 | pr_err("Failed to register cpuidle device for cpu%d\n", cpu); | |
736 | ||
737 | cpuidle_unregister(drv); | |
738 | break; | |
739 | } | |
740 | ||
741 | return ret; | |
742 | } | |
743 | EXPORT_SYMBOL_GPL(cpuidle_register); | |
744 | ||
4f86d3a8 LB |
745 | /** |
746 | * cpuidle_init - core initializer | |
747 | */ | |
748 | static int __init cpuidle_init(void) | |
749 | { | |
62027aea LB |
750 | if (cpuidle_disabled()) |
751 | return -ENODEV; | |
752 | ||
3a4a0042 | 753 | return cpuidle_add_interface(cpu_subsys.dev_root); |
4f86d3a8 LB |
754 | } |
755 | ||
62027aea | 756 | module_param(off, int, 0444); |
61cb5758 | 757 | module_param_string(governor, param_governor, CPUIDLE_NAME_LEN, 0444); |
4f86d3a8 | 758 | core_initcall(cpuidle_init); |