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Commit | Line | Data |
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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 RW |
77 | struct cpuidle_device *dev, |
78 | unsigned int max_latency, | |
79 | unsigned int forbidden_flags, | |
28ba086e | 80 | bool s2idle) |
a6220fc1 RW |
81 | { |
82 | unsigned int latency_req = 0; | |
51164251 | 83 | int i, ret = 0; |
a6220fc1 | 84 | |
51164251 | 85 | for (i = 1; i < drv->state_count; i++) { |
a6220fc1 RW |
86 | struct cpuidle_state *s = &drv->states[i]; |
87 | struct cpuidle_state_usage *su = &dev->states_usage[i]; | |
88 | ||
124cf911 | 89 | if (s->disabled || su->disable || s->exit_latency <= latency_req |
0d94039f RW |
90 | || s->exit_latency > max_latency |
91 | || (s->flags & forbidden_flags) | |
28ba086e | 92 | || (s2idle && !s->enter_s2idle)) |
a6220fc1 RW |
93 | continue; |
94 | ||
95 | latency_req = s->exit_latency; | |
96 | ret = i; | |
97 | } | |
98 | return ret; | |
99 | } | |
100 | ||
0e7414b7 RW |
101 | /** |
102 | * cpuidle_use_deepest_state - Set/clear governor override flag. | |
103 | * @enable: New value of the flag. | |
104 | * | |
105 | * Set/unset the current CPU to use the deepest idle state (override governors | |
106 | * going forward if set). | |
107 | */ | |
bb8313b6 JP |
108 | void cpuidle_use_deepest_state(bool enable) |
109 | { | |
110 | struct cpuidle_device *dev; | |
111 | ||
112 | preempt_disable(); | |
113 | dev = cpuidle_get_device(); | |
41dc750e LF |
114 | if (dev) |
115 | dev->use_deepest_state = enable; | |
bb8313b6 JP |
116 | preempt_enable(); |
117 | } | |
118 | ||
ef2b22ac RW |
119 | /** |
120 | * cpuidle_find_deepest_state - Find the deepest available idle state. | |
121 | * @drv: cpuidle driver for the given CPU. | |
122 | * @dev: cpuidle device for the given CPU. | |
123 | */ | |
124 | int cpuidle_find_deepest_state(struct cpuidle_driver *drv, | |
125 | struct cpuidle_device *dev) | |
126 | { | |
0d94039f | 127 | return find_deepest_state(drv, dev, UINT_MAX, 0, false); |
ef2b22ac RW |
128 | } |
129 | ||
bb8313b6 | 130 | #ifdef CONFIG_SUSPEND |
28ba086e | 131 | static void enter_s2idle_proper(struct cpuidle_driver *drv, |
124cf911 RW |
132 | struct cpuidle_device *dev, int index) |
133 | { | |
64bdff69 RW |
134 | ktime_t time_start, time_end; |
135 | ||
136 | time_start = ns_to_ktime(local_clock()); | |
137 | ||
ae0afb4f RW |
138 | /* |
139 | * trace_suspend_resume() called by tick_freeze() for the last CPU | |
140 | * executing it contains RCU usage regarded as invalid in the idle | |
141 | * context, so tell RCU about that. | |
142 | */ | |
143 | RCU_NONIDLE(tick_freeze()); | |
124cf911 RW |
144 | /* |
145 | * The state used here cannot be a "coupled" one, because the "coupled" | |
146 | * cpuidle mechanism enables interrupts and doing that with timekeeping | |
147 | * suspended is generally unsafe. | |
148 | */ | |
63caae84 | 149 | stop_critical_timings(); |
28ba086e | 150 | drv->states[index].enter_s2idle(dev, drv, index); |
124cf911 RW |
151 | WARN_ON(!irqs_disabled()); |
152 | /* | |
153 | * timekeeping_resume() that will be called by tick_unfreeze() for the | |
ae0afb4f | 154 | * first CPU executing it calls functions containing RCU read-side |
124cf911 RW |
155 | * critical sections, so tell RCU about that. |
156 | */ | |
157 | RCU_NONIDLE(tick_unfreeze()); | |
63caae84 | 158 | start_critical_timings(); |
64bdff69 RW |
159 | |
160 | time_end = ns_to_ktime(local_clock()); | |
161 | ||
162 | dev->states_usage[index].s2idle_time += ktime_us_delta(time_end, time_start); | |
163 | dev->states_usage[index].s2idle_usage++; | |
124cf911 RW |
164 | } |
165 | ||
38106313 | 166 | /** |
28ba086e | 167 | * cpuidle_enter_s2idle - Enter an idle state suitable for suspend-to-idle. |
ef2b22ac RW |
168 | * @drv: cpuidle driver for the given CPU. |
169 | * @dev: cpuidle device for the given CPU. | |
38106313 | 170 | * |
28ba086e | 171 | * If there are states with the ->enter_s2idle callback, find the deepest of |
ef2b22ac | 172 | * them and enter it with frozen tick. |
38106313 | 173 | */ |
28ba086e | 174 | int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
38106313 | 175 | { |
38106313 RW |
176 | int index; |
177 | ||
124cf911 | 178 | /* |
28ba086e | 179 | * Find the deepest state with ->enter_s2idle present, which guarantees |
124cf911 RW |
180 | * that interrupts won't be enabled when it exits and allows the tick to |
181 | * be frozen safely. | |
182 | */ | |
0d94039f | 183 | index = find_deepest_state(drv, dev, UINT_MAX, 0, true); |
6f16886b | 184 | if (index > 0) |
28ba086e | 185 | enter_s2idle_proper(drv, dev, index); |
124cf911 | 186 | |
ef2b22ac | 187 | return index; |
38106313 | 188 | } |
87e9b9f1 | 189 | #endif /* CONFIG_SUSPEND */ |
38106313 | 190 | |
56cfbf74 CC |
191 | /** |
192 | * cpuidle_enter_state - enter the state and update stats | |
193 | * @dev: cpuidle device for this cpu | |
194 | * @drv: cpuidle driver for this cpu | |
7312280b | 195 | * @index: index into the states table in @drv of the state to enter |
56cfbf74 CC |
196 | */ |
197 | int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, | |
554c06ba | 198 | int index) |
56cfbf74 CC |
199 | { |
200 | int entered_state; | |
201 | ||
554c06ba | 202 | struct cpuidle_state *target_state = &drv->states[index]; |
df8d9eea | 203 | bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP); |
dbd1b8ea | 204 | ktime_t time_start, time_end; |
554c06ba | 205 | |
df8d9eea RW |
206 | /* |
207 | * Tell the time framework to switch to a broadcast timer because our | |
208 | * local timer will be shut down. If a local timer is used from another | |
209 | * CPU as a broadcast timer, this call may fail if it is not available. | |
210 | */ | |
827a5aef | 211 | if (broadcast && tick_broadcast_enter()) { |
0d94039f RW |
212 | index = find_deepest_state(drv, dev, target_state->exit_latency, |
213 | CPUIDLE_FLAG_TIMER_STOP, false); | |
214 | if (index < 0) { | |
215 | default_idle_call(); | |
216 | return -EBUSY; | |
217 | } | |
218 | target_state = &drv->states[index]; | |
f187851b | 219 | broadcast = false; |
827a5aef | 220 | } |
df8d9eea | 221 | |
faad3849 RW |
222 | /* Take note of the planned idle state. */ |
223 | sched_idle_set_state(target_state); | |
224 | ||
30fe6884 | 225 | trace_cpu_idle_rcuidle(index, dev->cpu); |
dbd1b8ea | 226 | time_start = ns_to_ktime(local_clock()); |
554c06ba | 227 | |
63caae84 | 228 | stop_critical_timings(); |
554c06ba | 229 | entered_state = target_state->enter(dev, drv, index); |
63caae84 | 230 | start_critical_timings(); |
554c06ba | 231 | |
f9fccdb9 | 232 | sched_clock_idle_wakeup_event(); |
dbd1b8ea | 233 | time_end = ns_to_ktime(local_clock()); |
30fe6884 | 234 | trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); |
554c06ba | 235 | |
faad3849 RW |
236 | /* The cpu is no longer idle or about to enter idle. */ |
237 | sched_idle_set_state(NULL); | |
238 | ||
df8d9eea RW |
239 | if (broadcast) { |
240 | if (WARN_ON_ONCE(!irqs_disabled())) | |
241 | local_irq_disable(); | |
242 | ||
243 | tick_broadcast_exit(); | |
244 | } | |
245 | ||
e7387da5 | 246 | if (!cpuidle_state_is_coupled(drv, index)) |
0b89e9aa | 247 | local_irq_enable(); |
554c06ba | 248 | |
56cfbf74 | 249 | if (entered_state >= 0) { |
04dab58a RW |
250 | s64 diff, delay = drv->states[entered_state].exit_latency; |
251 | int i; | |
252 | ||
7037b43e FL |
253 | /* |
254 | * Update cpuidle counters | |
255 | * This can be moved to within driver enter routine, | |
56cfbf74 CC |
256 | * but that results in multiple copies of same code. |
257 | */ | |
7037b43e FL |
258 | diff = ktime_us_delta(time_end, time_start); |
259 | if (diff > INT_MAX) | |
260 | diff = INT_MAX; | |
261 | ||
262 | dev->last_residency = (int)diff; | |
a474a515 | 263 | dev->states_usage[entered_state].time += dev->last_residency; |
56cfbf74 | 264 | dev->states_usage[entered_state].usage++; |
04dab58a RW |
265 | |
266 | if (diff < drv->states[entered_state].target_residency) { | |
267 | for (i = entered_state - 1; i >= 0; i--) { | |
268 | if (drv->states[i].disabled || | |
269 | dev->states_usage[i].disable) | |
270 | continue; | |
271 | ||
272 | /* Shallower states are enabled, so update. */ | |
273 | dev->states_usage[entered_state].above++; | |
274 | break; | |
275 | } | |
276 | } else if (diff > delay) { | |
277 | for (i = entered_state + 1; i < drv->state_count; i++) { | |
278 | if (drv->states[i].disabled || | |
279 | dev->states_usage[i].disable) | |
280 | continue; | |
281 | ||
282 | /* | |
283 | * Update if a deeper state would have been a | |
284 | * better match for the observed idle duration. | |
285 | */ | |
286 | if (diff - delay >= drv->states[i].target_residency) | |
287 | dev->states_usage[entered_state].below++; | |
288 | ||
289 | break; | |
290 | } | |
291 | } | |
56cfbf74 CC |
292 | } else { |
293 | dev->last_residency = 0; | |
294 | } | |
295 | ||
296 | return entered_state; | |
297 | } | |
298 | ||
4f86d3a8 | 299 | /** |
907e30f1 DL |
300 | * cpuidle_select - ask the cpuidle framework to choose an idle state |
301 | * | |
302 | * @drv: the cpuidle driver | |
303 | * @dev: the cpuidle device | |
45f1ff59 | 304 | * @stop_tick: indication on whether or not to stop the tick |
4f86d3a8 | 305 | * |
51164251 | 306 | * Returns the index of the idle state. The return value must not be negative. |
45f1ff59 RW |
307 | * |
308 | * The memory location pointed to by @stop_tick is expected to be written the | |
309 | * 'false' boolean value if the scheduler tick should not be stopped before | |
310 | * entering the returned state. | |
4f86d3a8 | 311 | */ |
45f1ff59 RW |
312 | int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, |
313 | bool *stop_tick) | |
4f86d3a8 | 314 | { |
45f1ff59 | 315 | return cpuidle_curr_governor->select(drv, dev, stop_tick); |
907e30f1 | 316 | } |
ba8f20c2 | 317 | |
907e30f1 DL |
318 | /** |
319 | * cpuidle_enter - enter into the specified idle state | |
320 | * | |
321 | * @drv: the cpuidle driver tied with the cpu | |
322 | * @dev: the cpuidle device | |
323 | * @index: the index in the idle state table | |
324 | * | |
325 | * Returns the index in the idle state, < 0 in case of error. | |
326 | * The error code depends on the backend driver | |
327 | */ | |
328 | int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, | |
329 | int index) | |
330 | { | |
4c1ed5a6 | 331 | if (cpuidle_state_is_coupled(drv, index)) |
907e30f1 DL |
332 | return cpuidle_enter_state_coupled(dev, drv, index); |
333 | return cpuidle_enter_state(dev, drv, index); | |
334 | } | |
b60e6a0e | 335 | |
907e30f1 DL |
336 | /** |
337 | * cpuidle_reflect - tell the underlying governor what was the state | |
338 | * we were in | |
339 | * | |
340 | * @dev : the cpuidle device | |
341 | * @index: the index in the idle state table | |
342 | * | |
343 | */ | |
344 | void cpuidle_reflect(struct cpuidle_device *dev, int index) | |
345 | { | |
a802ea96 | 346 | if (cpuidle_curr_governor->reflect && index >= 0) |
907e30f1 | 347 | cpuidle_curr_governor->reflect(dev, index); |
4f86d3a8 LB |
348 | } |
349 | ||
350 | /** | |
351 | * cpuidle_install_idle_handler - installs the cpuidle idle loop handler | |
352 | */ | |
353 | void cpuidle_install_idle_handler(void) | |
354 | { | |
a0bfa137 | 355 | if (enabled_devices) { |
4f86d3a8 LB |
356 | /* Make sure all changes finished before we switch to new idle */ |
357 | smp_wmb(); | |
a0bfa137 | 358 | initialized = 1; |
4f86d3a8 LB |
359 | } |
360 | } | |
361 | ||
362 | /** | |
363 | * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler | |
364 | */ | |
365 | void cpuidle_uninstall_idle_handler(void) | |
366 | { | |
a0bfa137 LB |
367 | if (enabled_devices) { |
368 | initialized = 0; | |
2ed903c5 | 369 | wake_up_all_idle_cpus(); |
4f86d3a8 | 370 | } |
442bf3aa DL |
371 | |
372 | /* | |
373 | * Make sure external observers (such as the scheduler) | |
374 | * are done looking at pointed idle states. | |
375 | */ | |
376 | synchronize_rcu(); | |
4f86d3a8 LB |
377 | } |
378 | ||
379 | /** | |
380 | * cpuidle_pause_and_lock - temporarily disables CPUIDLE | |
381 | */ | |
382 | void cpuidle_pause_and_lock(void) | |
383 | { | |
384 | mutex_lock(&cpuidle_lock); | |
385 | cpuidle_uninstall_idle_handler(); | |
386 | } | |
387 | ||
388 | EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock); | |
389 | ||
390 | /** | |
391 | * cpuidle_resume_and_unlock - resumes CPUIDLE operation | |
392 | */ | |
393 | void cpuidle_resume_and_unlock(void) | |
394 | { | |
395 | cpuidle_install_idle_handler(); | |
396 | mutex_unlock(&cpuidle_lock); | |
397 | } | |
398 | ||
399 | EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); | |
400 | ||
8651f97b PM |
401 | /* Currently used in suspend/resume path to suspend cpuidle */ |
402 | void cpuidle_pause(void) | |
403 | { | |
404 | mutex_lock(&cpuidle_lock); | |
405 | cpuidle_uninstall_idle_handler(); | |
406 | mutex_unlock(&cpuidle_lock); | |
407 | } | |
408 | ||
409 | /* Currently used in suspend/resume path to resume cpuidle */ | |
410 | void cpuidle_resume(void) | |
411 | { | |
412 | mutex_lock(&cpuidle_lock); | |
413 | cpuidle_install_idle_handler(); | |
414 | mutex_unlock(&cpuidle_lock); | |
415 | } | |
416 | ||
4f86d3a8 LB |
417 | /** |
418 | * cpuidle_enable_device - enables idle PM for a CPU | |
419 | * @dev: the CPU | |
420 | * | |
421 | * This function must be called between cpuidle_pause_and_lock and | |
422 | * cpuidle_resume_and_unlock when used externally. | |
423 | */ | |
424 | int cpuidle_enable_device(struct cpuidle_device *dev) | |
425 | { | |
5df0aa73 | 426 | int ret; |
bf4d1b5d | 427 | struct cpuidle_driver *drv; |
4f86d3a8 | 428 | |
1b0a0e9a SB |
429 | if (!dev) |
430 | return -EINVAL; | |
431 | ||
4f86d3a8 LB |
432 | if (dev->enabled) |
433 | return 0; | |
bf4d1b5d | 434 | |
e7b06a09 GJ |
435 | if (!cpuidle_curr_governor) |
436 | return -EIO; | |
437 | ||
bf4d1b5d DL |
438 | drv = cpuidle_get_cpu_driver(dev); |
439 | ||
e7b06a09 | 440 | if (!drv) |
4f86d3a8 | 441 | return -EIO; |
bf4d1b5d | 442 | |
10b9d3f8 DL |
443 | if (!dev->registered) |
444 | return -EINVAL; | |
445 | ||
bf4d1b5d DL |
446 | ret = cpuidle_add_device_sysfs(dev); |
447 | if (ret) | |
4f86d3a8 LB |
448 | return ret; |
449 | ||
3fc74bd8 GJ |
450 | if (cpuidle_curr_governor->enable) { |
451 | ret = cpuidle_curr_governor->enable(drv, dev); | |
452 | if (ret) | |
453 | goto fail_sysfs; | |
454 | } | |
4f86d3a8 | 455 | |
4f86d3a8 LB |
456 | smp_wmb(); |
457 | ||
458 | dev->enabled = 1; | |
459 | ||
460 | enabled_devices++; | |
461 | return 0; | |
462 | ||
463 | fail_sysfs: | |
bf4d1b5d | 464 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
465 | |
466 | return ret; | |
467 | } | |
468 | ||
469 | EXPORT_SYMBOL_GPL(cpuidle_enable_device); | |
470 | ||
471 | /** | |
472 | * cpuidle_disable_device - disables idle PM for a CPU | |
473 | * @dev: the CPU | |
474 | * | |
475 | * This function must be called between cpuidle_pause_and_lock and | |
476 | * cpuidle_resume_and_unlock when used externally. | |
477 | */ | |
478 | void cpuidle_disable_device(struct cpuidle_device *dev) | |
479 | { | |
bf4d1b5d DL |
480 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
481 | ||
cf31cd1a | 482 | if (!dev || !dev->enabled) |
4f86d3a8 | 483 | return; |
bf4d1b5d DL |
484 | |
485 | if (!drv || !cpuidle_curr_governor) | |
4f86d3a8 LB |
486 | return; |
487 | ||
488 | dev->enabled = 0; | |
489 | ||
490 | if (cpuidle_curr_governor->disable) | |
bf4d1b5d | 491 | cpuidle_curr_governor->disable(drv, dev); |
4f86d3a8 | 492 | |
bf4d1b5d | 493 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
494 | enabled_devices--; |
495 | } | |
496 | ||
497 | EXPORT_SYMBOL_GPL(cpuidle_disable_device); | |
498 | ||
f6bb51a5 DL |
499 | static void __cpuidle_unregister_device(struct cpuidle_device *dev) |
500 | { | |
501 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); | |
502 | ||
503 | list_del(&dev->device_list); | |
504 | per_cpu(cpuidle_devices, dev->cpu) = NULL; | |
505 | module_put(drv->owner); | |
c998c078 DG |
506 | |
507 | dev->registered = 0; | |
f6bb51a5 DL |
508 | } |
509 | ||
267d4bf8 | 510 | static void __cpuidle_device_init(struct cpuidle_device *dev) |
5df0aa73 DL |
511 | { |
512 | memset(dev->states_usage, 0, sizeof(dev->states_usage)); | |
513 | dev->last_residency = 0; | |
5df0aa73 DL |
514 | } |
515 | ||
4f86d3a8 | 516 | /** |
dcb84f33 VP |
517 | * __cpuidle_register_device - internal register function called before register |
518 | * and enable routines | |
4f86d3a8 | 519 | * @dev: the cpu |
dcb84f33 VP |
520 | * |
521 | * cpuidle_lock mutex must be held before this is called | |
4f86d3a8 | 522 | */ |
dcb84f33 | 523 | static int __cpuidle_register_device(struct cpuidle_device *dev) |
4f86d3a8 LB |
524 | { |
525 | int ret; | |
bf4d1b5d | 526 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
4f86d3a8 | 527 | |
bf4d1b5d | 528 | if (!try_module_get(drv->owner)) |
4f86d3a8 LB |
529 | return -EINVAL; |
530 | ||
4f86d3a8 LB |
531 | per_cpu(cpuidle_devices, dev->cpu) = dev; |
532 | list_add(&dev->device_list, &cpuidle_detected_devices); | |
4f86d3a8 | 533 | |
4126c019 | 534 | ret = cpuidle_coupled_register_device(dev); |
47182668 | 535 | if (ret) |
f6bb51a5 | 536 | __cpuidle_unregister_device(dev); |
47182668 VK |
537 | else |
538 | dev->registered = 1; | |
4f86d3a8 | 539 | |
47182668 | 540 | return ret; |
dcb84f33 VP |
541 | } |
542 | ||
543 | /** | |
544 | * cpuidle_register_device - registers a CPU's idle PM feature | |
545 | * @dev: the cpu | |
546 | */ | |
547 | int cpuidle_register_device(struct cpuidle_device *dev) | |
548 | { | |
c878a52d | 549 | int ret = -EBUSY; |
dcb84f33 | 550 | |
1b0a0e9a SB |
551 | if (!dev) |
552 | return -EINVAL; | |
553 | ||
dcb84f33 VP |
554 | mutex_lock(&cpuidle_lock); |
555 | ||
c878a52d DL |
556 | if (dev->registered) |
557 | goto out_unlock; | |
558 | ||
267d4bf8 | 559 | __cpuidle_device_init(dev); |
5df0aa73 | 560 | |
f6bb51a5 DL |
561 | ret = __cpuidle_register_device(dev); |
562 | if (ret) | |
563 | goto out_unlock; | |
564 | ||
565 | ret = cpuidle_add_sysfs(dev); | |
566 | if (ret) | |
567 | goto out_unregister; | |
dcb84f33 | 568 | |
10b9d3f8 | 569 | ret = cpuidle_enable_device(dev); |
f6bb51a5 DL |
570 | if (ret) |
571 | goto out_sysfs; | |
10b9d3f8 | 572 | |
4f86d3a8 LB |
573 | cpuidle_install_idle_handler(); |
574 | ||
f6bb51a5 | 575 | out_unlock: |
4f86d3a8 LB |
576 | mutex_unlock(&cpuidle_lock); |
577 | ||
f6bb51a5 DL |
578 | return ret; |
579 | ||
580 | out_sysfs: | |
581 | cpuidle_remove_sysfs(dev); | |
582 | out_unregister: | |
583 | __cpuidle_unregister_device(dev); | |
584 | goto out_unlock; | |
4f86d3a8 LB |
585 | } |
586 | ||
587 | EXPORT_SYMBOL_GPL(cpuidle_register_device); | |
588 | ||
589 | /** | |
590 | * cpuidle_unregister_device - unregisters a CPU's idle PM feature | |
591 | * @dev: the cpu | |
592 | */ | |
593 | void cpuidle_unregister_device(struct cpuidle_device *dev) | |
594 | { | |
813e8e3d | 595 | if (!dev || dev->registered == 0) |
dcb84f33 VP |
596 | return; |
597 | ||
4f86d3a8 LB |
598 | cpuidle_pause_and_lock(); |
599 | ||
600 | cpuidle_disable_device(dev); | |
601 | ||
1aef40e2 | 602 | cpuidle_remove_sysfs(dev); |
f6bb51a5 DL |
603 | |
604 | __cpuidle_unregister_device(dev); | |
4f86d3a8 | 605 | |
4126c019 CC |
606 | cpuidle_coupled_unregister_device(dev); |
607 | ||
4f86d3a8 | 608 | cpuidle_resume_and_unlock(); |
4f86d3a8 LB |
609 | } |
610 | ||
611 | EXPORT_SYMBOL_GPL(cpuidle_unregister_device); | |
612 | ||
1c192d04 | 613 | /** |
4c637b21 DL |
614 | * cpuidle_unregister: unregister a driver and the devices. This function |
615 | * can be used only if the driver has been previously registered through | |
616 | * the cpuidle_register function. | |
617 | * | |
618 | * @drv: a valid pointer to a struct cpuidle_driver | |
619 | */ | |
620 | void cpuidle_unregister(struct cpuidle_driver *drv) | |
621 | { | |
622 | int cpu; | |
623 | struct cpuidle_device *device; | |
624 | ||
82467a5a | 625 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
626 | device = &per_cpu(cpuidle_dev, cpu); |
627 | cpuidle_unregister_device(device); | |
628 | } | |
629 | ||
630 | cpuidle_unregister_driver(drv); | |
631 | } | |
632 | EXPORT_SYMBOL_GPL(cpuidle_unregister); | |
633 | ||
634 | /** | |
635 | * cpuidle_register: registers the driver and the cpu devices with the | |
636 | * coupled_cpus passed as parameter. This function is used for all common | |
637 | * initialization pattern there are in the arch specific drivers. The | |
638 | * devices is globally defined in this file. | |
639 | * | |
640 | * @drv : a valid pointer to a struct cpuidle_driver | |
641 | * @coupled_cpus: a cpumask for the coupled states | |
642 | * | |
643 | * Returns 0 on success, < 0 otherwise | |
644 | */ | |
645 | int cpuidle_register(struct cpuidle_driver *drv, | |
646 | const struct cpumask *const coupled_cpus) | |
647 | { | |
648 | int ret, cpu; | |
649 | struct cpuidle_device *device; | |
650 | ||
651 | ret = cpuidle_register_driver(drv); | |
652 | if (ret) { | |
653 | pr_err("failed to register cpuidle driver\n"); | |
654 | return ret; | |
655 | } | |
656 | ||
82467a5a | 657 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
658 | device = &per_cpu(cpuidle_dev, cpu); |
659 | device->cpu = cpu; | |
660 | ||
661 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED | |
662 | /* | |
caf4a36e | 663 | * On multiplatform for ARM, the coupled idle states could be |
4c637b21 DL |
664 | * enabled in the kernel even if the cpuidle driver does not |
665 | * use it. Note, coupled_cpus is a struct copy. | |
666 | */ | |
667 | if (coupled_cpus) | |
668 | device->coupled_cpus = *coupled_cpus; | |
669 | #endif | |
670 | ret = cpuidle_register_device(device); | |
671 | if (!ret) | |
672 | continue; | |
673 | ||
674 | pr_err("Failed to register cpuidle device for cpu%d\n", cpu); | |
675 | ||
676 | cpuidle_unregister(drv); | |
677 | break; | |
678 | } | |
679 | ||
680 | return ret; | |
681 | } | |
682 | EXPORT_SYMBOL_GPL(cpuidle_register); | |
683 | ||
4f86d3a8 LB |
684 | #ifdef CONFIG_SMP |
685 | ||
4f86d3a8 LB |
686 | /* |
687 | * This function gets called when a part of the kernel has a new latency | |
688 | * requirement. This means we need to get all processors out of their C-state, | |
689 | * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that | |
690 | * wakes them all right up. | |
691 | */ | |
692 | static int cpuidle_latency_notify(struct notifier_block *b, | |
693 | unsigned long l, void *v) | |
694 | { | |
2ed903c5 | 695 | wake_up_all_idle_cpus(); |
4f86d3a8 LB |
696 | return NOTIFY_OK; |
697 | } | |
698 | ||
699 | static struct notifier_block cpuidle_latency_notifier = { | |
700 | .notifier_call = cpuidle_latency_notify, | |
701 | }; | |
702 | ||
d82b3518 MG |
703 | static inline void latency_notifier_init(struct notifier_block *n) |
704 | { | |
705 | pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n); | |
706 | } | |
4f86d3a8 LB |
707 | |
708 | #else /* CONFIG_SMP */ | |
709 | ||
710 | #define latency_notifier_init(x) do { } while (0) | |
711 | ||
712 | #endif /* CONFIG_SMP */ | |
713 | ||
714 | /** | |
715 | * cpuidle_init - core initializer | |
716 | */ | |
717 | static int __init cpuidle_init(void) | |
718 | { | |
719 | int ret; | |
720 | ||
62027aea LB |
721 | if (cpuidle_disabled()) |
722 | return -ENODEV; | |
723 | ||
8a25a2fd | 724 | ret = cpuidle_add_interface(cpu_subsys.dev_root); |
4f86d3a8 LB |
725 | if (ret) |
726 | return ret; | |
727 | ||
728 | latency_notifier_init(&cpuidle_latency_notifier); | |
729 | ||
730 | return 0; | |
731 | } | |
732 | ||
62027aea | 733 | module_param(off, int, 0444); |
61cb5758 | 734 | module_param_string(governor, param_governor, CPUIDLE_NAME_LEN, 0444); |
4f86d3a8 | 735 | core_initcall(cpuidle_init); |