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 | ||
6ab4b199 | 11 | #include "linux/percpu-defs.h" |
b60e6a0e | 12 | #include <linux/clockchips.h> |
4f86d3a8 LB |
13 | #include <linux/kernel.h> |
14 | #include <linux/mutex.h> | |
15 | #include <linux/sched.h> | |
e6017571 | 16 | #include <linux/sched/clock.h> |
4f86d3a8 | 17 | #include <linux/notifier.h> |
e8db0be1 | 18 | #include <linux/pm_qos.h> |
4f86d3a8 LB |
19 | #include <linux/cpu.h> |
20 | #include <linux/cpuidle.h> | |
9a0b8415 | 21 | #include <linux/ktime.h> |
2e94d1f7 | 22 | #include <linux/hrtimer.h> |
884b17e1 | 23 | #include <linux/module.h> |
38106313 | 24 | #include <linux/suspend.h> |
124cf911 | 25 | #include <linux/tick.h> |
bf9282dc | 26 | #include <linux/mmu_context.h> |
e67198cc | 27 | #include <linux/context_tracking.h> |
288f023e | 28 | #include <trace/events/power.h> |
4f86d3a8 LB |
29 | |
30 | #include "cpuidle.h" | |
31 | ||
32 | DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices); | |
4c637b21 | 33 | DEFINE_PER_CPU(struct cpuidle_device, cpuidle_dev); |
4f86d3a8 LB |
34 | |
35 | DEFINE_MUTEX(cpuidle_lock); | |
36 | LIST_HEAD(cpuidle_detected_devices); | |
4f86d3a8 LB |
37 | |
38 | static int enabled_devices; | |
62027aea | 39 | static int off __read_mostly; |
a0bfa137 | 40 | static int initialized __read_mostly; |
62027aea LB |
41 | |
42 | int cpuidle_disabled(void) | |
43 | { | |
44 | return off; | |
45 | } | |
d91ee586 LB |
46 | void disable_cpuidle(void) |
47 | { | |
48 | off = 1; | |
49 | } | |
4f86d3a8 | 50 | |
ef2b22ac RW |
51 | bool cpuidle_not_available(struct cpuidle_driver *drv, |
52 | struct cpuidle_device *dev) | |
31a34090 RW |
53 | { |
54 | return off || !initialized || !drv || !dev || !dev->enabled; | |
55 | } | |
56 | ||
1a022e3f BO |
57 | /** |
58 | * cpuidle_play_dead - cpu off-lining | |
59 | * | |
ee01e663 | 60 | * Returns in case of an error or no driver |
1a022e3f BO |
61 | */ |
62 | int cpuidle_play_dead(void) | |
63 | { | |
64 | struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); | |
bf4d1b5d | 65 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
8aef33a7 | 66 | int i; |
1a022e3f | 67 | |
ee01e663 TK |
68 | if (!drv) |
69 | return -ENODEV; | |
70 | ||
1a022e3f | 71 | /* Find lowest-power state that supports long-term idle */ |
7d51d979 | 72 | for (i = drv->state_count - 1; i >= 0; i--) |
8aef33a7 DL |
73 | if (drv->states[i].enter_dead) |
74 | return drv->states[i].enter_dead(dev, i); | |
1a022e3f BO |
75 | |
76 | return -ENODEV; | |
77 | } | |
78 | ||
ef2b22ac | 79 | static int find_deepest_state(struct cpuidle_driver *drv, |
0d94039f | 80 | struct cpuidle_device *dev, |
c1d51f68 | 81 | u64 max_latency_ns, |
0d94039f | 82 | unsigned int forbidden_flags, |
28ba086e | 83 | bool s2idle) |
a6220fc1 | 84 | { |
c1d51f68 | 85 | u64 latency_req = 0; |
51164251 | 86 | int i, ret = 0; |
a6220fc1 | 87 | |
51164251 | 88 | for (i = 1; i < drv->state_count; i++) { |
a6220fc1 | 89 | struct cpuidle_state *s = &drv->states[i]; |
a6220fc1 | 90 | |
99e98d3f | 91 | if (dev->states_usage[i].disable || |
c1d51f68 RW |
92 | s->exit_latency_ns <= latency_req || |
93 | s->exit_latency_ns > max_latency_ns || | |
99e98d3f RW |
94 | (s->flags & forbidden_flags) || |
95 | (s2idle && !s->enter_s2idle)) | |
a6220fc1 RW |
96 | continue; |
97 | ||
c1d51f68 | 98 | latency_req = s->exit_latency_ns; |
a6220fc1 RW |
99 | ret = i; |
100 | } | |
101 | return ret; | |
102 | } | |
103 | ||
0e7414b7 | 104 | /** |
c55b51a0 DL |
105 | * cpuidle_use_deepest_state - Set/unset governor override mode. |
106 | * @latency_limit_ns: Idle state exit latency limit (or no override if 0). | |
0e7414b7 | 107 | * |
c55b51a0 DL |
108 | * If @latency_limit_ns is nonzero, set the current CPU to use the deepest idle |
109 | * state with exit latency within @latency_limit_ns (override governors going | |
110 | * forward), or do not override governors if it is zero. | |
0e7414b7 | 111 | */ |
c55b51a0 | 112 | void cpuidle_use_deepest_state(u64 latency_limit_ns) |
bb8313b6 JP |
113 | { |
114 | struct cpuidle_device *dev; | |
115 | ||
116 | preempt_disable(); | |
117 | dev = cpuidle_get_device(); | |
41dc750e | 118 | if (dev) |
c55b51a0 | 119 | dev->forced_idle_latency_limit_ns = latency_limit_ns; |
bb8313b6 JP |
120 | preempt_enable(); |
121 | } | |
122 | ||
ef2b22ac RW |
123 | /** |
124 | * cpuidle_find_deepest_state - Find the deepest available idle state. | |
125 | * @drv: cpuidle driver for the given CPU. | |
126 | * @dev: cpuidle device for the given CPU. | |
cefb9409 BG |
127 | * @latency_limit_ns: Idle state exit latency limit |
128 | * | |
129 | * Return: the index of the deepest available idle state. | |
ef2b22ac RW |
130 | */ |
131 | int cpuidle_find_deepest_state(struct cpuidle_driver *drv, | |
5aa9ba63 DL |
132 | struct cpuidle_device *dev, |
133 | u64 latency_limit_ns) | |
ef2b22ac | 134 | { |
5aa9ba63 | 135 | return find_deepest_state(drv, dev, latency_limit_ns, 0, false); |
ef2b22ac RW |
136 | } |
137 | ||
bb8313b6 | 138 | #ifdef CONFIG_SUSPEND |
28ba086e | 139 | static void enter_s2idle_proper(struct cpuidle_driver *drv, |
124cf911 RW |
140 | struct cpuidle_device *dev, int index) |
141 | { | |
64bdff69 | 142 | ktime_t time_start, time_end; |
8747f202 | 143 | struct cpuidle_state *target_state = &drv->states[index]; |
64bdff69 RW |
144 | |
145 | time_start = ns_to_ktime(local_clock()); | |
146 | ||
1098582a | 147 | tick_freeze(); |
124cf911 RW |
148 | /* |
149 | * The state used here cannot be a "coupled" one, because the "coupled" | |
150 | * cpuidle mechanism enables interrupts and doing that with timekeeping | |
151 | * suspended is generally unsafe. | |
152 | */ | |
63caae84 | 153 | stop_critical_timings(); |
8747f202 | 154 | if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) |
e67198cc | 155 | ct_idle_enter(); |
8747f202 | 156 | target_state->enter_s2idle(dev, drv, index); |
49d9c593 PZ |
157 | if (WARN_ON_ONCE(!irqs_disabled())) |
158 | local_irq_disable(); | |
8747f202 | 159 | if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) |
e67198cc | 160 | ct_idle_exit(); |
1098582a | 161 | tick_unfreeze(); |
63caae84 | 162 | start_critical_timings(); |
64bdff69 RW |
163 | |
164 | time_end = ns_to_ktime(local_clock()); | |
165 | ||
166 | dev->states_usage[index].s2idle_time += ktime_us_delta(time_end, time_start); | |
167 | dev->states_usage[index].s2idle_usage++; | |
124cf911 RW |
168 | } |
169 | ||
38106313 | 170 | /** |
28ba086e | 171 | * cpuidle_enter_s2idle - Enter an idle state suitable for suspend-to-idle. |
ef2b22ac RW |
172 | * @drv: cpuidle driver for the given CPU. |
173 | * @dev: cpuidle device for the given CPU. | |
38106313 | 174 | * |
28ba086e | 175 | * If there are states with the ->enter_s2idle callback, find the deepest of |
ef2b22ac | 176 | * them and enter it with frozen tick. |
38106313 | 177 | */ |
28ba086e | 178 | int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
38106313 | 179 | { |
38106313 RW |
180 | int index; |
181 | ||
124cf911 | 182 | /* |
28ba086e | 183 | * Find the deepest state with ->enter_s2idle present, which guarantees |
124cf911 RW |
184 | * that interrupts won't be enabled when it exits and allows the tick to |
185 | * be frozen safely. | |
186 | */ | |
c1d51f68 | 187 | index = find_deepest_state(drv, dev, U64_MAX, 0, true); |
10e8b11e | 188 | if (index > 0) { |
28ba086e | 189 | enter_s2idle_proper(drv, dev, index); |
10e8b11e RW |
190 | local_irq_enable(); |
191 | } | |
ef2b22ac | 192 | return index; |
38106313 | 193 | } |
87e9b9f1 | 194 | #endif /* CONFIG_SUSPEND */ |
38106313 | 195 | |
56cfbf74 CC |
196 | /** |
197 | * cpuidle_enter_state - enter the state and update stats | |
198 | * @dev: cpuidle device for this cpu | |
199 | * @drv: cpuidle driver for this cpu | |
7312280b | 200 | * @index: index into the states table in @drv of the state to enter |
56cfbf74 CC |
201 | */ |
202 | int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, | |
554c06ba | 203 | int index) |
56cfbf74 CC |
204 | { |
205 | int entered_state; | |
206 | ||
554c06ba | 207 | struct cpuidle_state *target_state = &drv->states[index]; |
df8d9eea | 208 | bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP); |
dbd1b8ea | 209 | ktime_t time_start, time_end; |
554c06ba | 210 | |
df8d9eea RW |
211 | /* |
212 | * Tell the time framework to switch to a broadcast timer because our | |
213 | * local timer will be shut down. If a local timer is used from another | |
214 | * CPU as a broadcast timer, this call may fail if it is not available. | |
215 | */ | |
827a5aef | 216 | if (broadcast && tick_broadcast_enter()) { |
c1d51f68 | 217 | index = find_deepest_state(drv, dev, target_state->exit_latency_ns, |
0d94039f RW |
218 | CPUIDLE_FLAG_TIMER_STOP, false); |
219 | if (index < 0) { | |
220 | default_idle_call(); | |
221 | return -EBUSY; | |
222 | } | |
223 | target_state = &drv->states[index]; | |
f187851b | 224 | broadcast = false; |
827a5aef | 225 | } |
df8d9eea | 226 | |
bf9282dc PZ |
227 | if (target_state->flags & CPUIDLE_FLAG_TLB_FLUSHED) |
228 | leave_mm(dev->cpu); | |
229 | ||
faad3849 RW |
230 | /* Take note of the planned idle state. */ |
231 | sched_idle_set_state(target_state); | |
232 | ||
1098582a | 233 | trace_cpu_idle(index, dev->cpu); |
dbd1b8ea | 234 | time_start = ns_to_ktime(local_clock()); |
554c06ba | 235 | |
63caae84 | 236 | stop_critical_timings(); |
8747f202 | 237 | if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) |
e67198cc | 238 | ct_idle_enter(); |
554c06ba | 239 | entered_state = target_state->enter(dev, drv, index); |
8747f202 | 240 | if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) |
e67198cc | 241 | ct_idle_exit(); |
63caae84 | 242 | start_critical_timings(); |
554c06ba | 243 | |
f9fccdb9 | 244 | sched_clock_idle_wakeup_event(); |
dbd1b8ea | 245 | time_end = ns_to_ktime(local_clock()); |
1098582a | 246 | trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu); |
554c06ba | 247 | |
faad3849 RW |
248 | /* The cpu is no longer idle or about to enter idle. */ |
249 | sched_idle_set_state(NULL); | |
250 | ||
df8d9eea RW |
251 | if (broadcast) { |
252 | if (WARN_ON_ONCE(!irqs_disabled())) | |
253 | local_irq_disable(); | |
254 | ||
255 | tick_broadcast_exit(); | |
256 | } | |
257 | ||
e7387da5 | 258 | if (!cpuidle_state_is_coupled(drv, index)) |
0b89e9aa | 259 | local_irq_enable(); |
554c06ba | 260 | |
56cfbf74 | 261 | if (entered_state >= 0) { |
c1d51f68 | 262 | s64 diff, delay = drv->states[entered_state].exit_latency_ns; |
04dab58a RW |
263 | int i; |
264 | ||
7037b43e FL |
265 | /* |
266 | * Update cpuidle counters | |
267 | * This can be moved to within driver enter routine, | |
56cfbf74 CC |
268 | * but that results in multiple copies of same code. |
269 | */ | |
c1d51f68 | 270 | diff = ktime_sub(time_end, time_start); |
7037b43e | 271 | |
c1d51f68 RW |
272 | dev->last_residency_ns = diff; |
273 | dev->states_usage[entered_state].time_ns += diff; | |
56cfbf74 | 274 | dev->states_usage[entered_state].usage++; |
04dab58a | 275 | |
c1d51f68 | 276 | if (diff < drv->states[entered_state].target_residency_ns) { |
04dab58a | 277 | for (i = entered_state - 1; i >= 0; i--) { |
99e98d3f | 278 | if (dev->states_usage[i].disable) |
04dab58a RW |
279 | continue; |
280 | ||
281 | /* Shallower states are enabled, so update. */ | |
282 | dev->states_usage[entered_state].above++; | |
6ab4b199 | 283 | trace_cpu_idle_miss(dev->cpu, entered_state, false); |
04dab58a RW |
284 | break; |
285 | } | |
286 | } else if (diff > delay) { | |
287 | for (i = entered_state + 1; i < drv->state_count; i++) { | |
99e98d3f | 288 | if (dev->states_usage[i].disable) |
04dab58a RW |
289 | continue; |
290 | ||
291 | /* | |
292 | * Update if a deeper state would have been a | |
293 | * better match for the observed idle duration. | |
294 | */ | |
6ab4b199 | 295 | if (diff - delay >= drv->states[i].target_residency_ns) { |
04dab58a | 296 | dev->states_usage[entered_state].below++; |
6ab4b199 KP |
297 | trace_cpu_idle_miss(dev->cpu, entered_state, true); |
298 | } | |
04dab58a RW |
299 | |
300 | break; | |
301 | } | |
302 | } | |
56cfbf74 | 303 | } else { |
c1d51f68 | 304 | dev->last_residency_ns = 0; |
f49735f4 | 305 | dev->states_usage[index].rejected++; |
56cfbf74 CC |
306 | } |
307 | ||
308 | return entered_state; | |
309 | } | |
310 | ||
4f86d3a8 | 311 | /** |
907e30f1 DL |
312 | * cpuidle_select - ask the cpuidle framework to choose an idle state |
313 | * | |
314 | * @drv: the cpuidle driver | |
315 | * @dev: the cpuidle device | |
45f1ff59 | 316 | * @stop_tick: indication on whether or not to stop the tick |
4f86d3a8 | 317 | * |
51164251 | 318 | * Returns the index of the idle state. The return value must not be negative. |
45f1ff59 RW |
319 | * |
320 | * The memory location pointed to by @stop_tick is expected to be written the | |
321 | * 'false' boolean value if the scheduler tick should not be stopped before | |
322 | * entering the returned state. | |
4f86d3a8 | 323 | */ |
45f1ff59 RW |
324 | int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, |
325 | bool *stop_tick) | |
4f86d3a8 | 326 | { |
45f1ff59 | 327 | return cpuidle_curr_governor->select(drv, dev, stop_tick); |
907e30f1 | 328 | } |
ba8f20c2 | 329 | |
907e30f1 DL |
330 | /** |
331 | * cpuidle_enter - enter into the specified idle state | |
332 | * | |
333 | * @drv: the cpuidle driver tied with the cpu | |
334 | * @dev: the cpuidle device | |
335 | * @index: the index in the idle state table | |
336 | * | |
337 | * Returns the index in the idle state, < 0 in case of error. | |
338 | * The error code depends on the backend driver | |
339 | */ | |
340 | int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, | |
341 | int index) | |
342 | { | |
6f9b83ac UH |
343 | int ret = 0; |
344 | ||
345 | /* | |
346 | * Store the next hrtimer, which becomes either next tick or the next | |
347 | * timer event, whatever expires first. Additionally, to make this data | |
348 | * useful for consumers outside cpuidle, we rely on that the governor's | |
349 | * ->select() callback have decided, whether to stop the tick or not. | |
350 | */ | |
351 | WRITE_ONCE(dev->next_hrtimer, tick_nohz_get_next_hrtimer()); | |
352 | ||
4c1ed5a6 | 353 | if (cpuidle_state_is_coupled(drv, index)) |
6f9b83ac UH |
354 | ret = cpuidle_enter_state_coupled(dev, drv, index); |
355 | else | |
356 | ret = cpuidle_enter_state(dev, drv, index); | |
357 | ||
358 | WRITE_ONCE(dev->next_hrtimer, 0); | |
359 | return ret; | |
907e30f1 | 360 | } |
b60e6a0e | 361 | |
907e30f1 DL |
362 | /** |
363 | * cpuidle_reflect - tell the underlying governor what was the state | |
364 | * we were in | |
365 | * | |
366 | * @dev : the cpuidle device | |
367 | * @index: the index in the idle state table | |
368 | * | |
369 | */ | |
370 | void cpuidle_reflect(struct cpuidle_device *dev, int index) | |
371 | { | |
a802ea96 | 372 | if (cpuidle_curr_governor->reflect && index >= 0) |
907e30f1 | 373 | cpuidle_curr_governor->reflect(dev, index); |
4f86d3a8 LB |
374 | } |
375 | ||
7a25759e MG |
376 | /* |
377 | * Min polling interval of 10usec is a guess. It is assuming that | |
378 | * for most users, the time for a single ping-pong workload like | |
379 | * perf bench pipe would generally complete within 10usec but | |
380 | * this is hardware dependant. Actual time can be estimated with | |
381 | * | |
382 | * perf bench sched pipe -l 10000 | |
383 | * | |
384 | * Run multiple times to avoid cpufreq effects. | |
385 | */ | |
386 | #define CPUIDLE_POLL_MIN 10000 | |
387 | #define CPUIDLE_POLL_MAX (TICK_NSEC / 16) | |
388 | ||
259231a0 MT |
389 | /** |
390 | * cpuidle_poll_time - return amount of time to poll for, | |
391 | * governors can override dev->poll_limit_ns if necessary | |
392 | * | |
393 | * @drv: the cpuidle driver tied with the cpu | |
394 | * @dev: the cpuidle device | |
395 | * | |
396 | */ | |
397 | u64 cpuidle_poll_time(struct cpuidle_driver *drv, | |
398 | struct cpuidle_device *dev) | |
399 | { | |
400 | int i; | |
401 | u64 limit_ns; | |
402 | ||
7a25759e MG |
403 | BUILD_BUG_ON(CPUIDLE_POLL_MIN > CPUIDLE_POLL_MAX); |
404 | ||
259231a0 MT |
405 | if (dev->poll_limit_ns) |
406 | return dev->poll_limit_ns; | |
407 | ||
7a25759e | 408 | limit_ns = CPUIDLE_POLL_MAX; |
259231a0 | 409 | for (i = 1; i < drv->state_count; i++) { |
7a25759e MG |
410 | u64 state_limit; |
411 | ||
99e98d3f | 412 | if (dev->states_usage[i].disable) |
259231a0 MT |
413 | continue; |
414 | ||
7a25759e MG |
415 | state_limit = drv->states[i].target_residency_ns; |
416 | if (state_limit < CPUIDLE_POLL_MIN) | |
417 | continue; | |
418 | ||
419 | limit_ns = min_t(u64, state_limit, CPUIDLE_POLL_MAX); | |
36fcb429 | 420 | break; |
259231a0 MT |
421 | } |
422 | ||
423 | dev->poll_limit_ns = limit_ns; | |
424 | ||
425 | return dev->poll_limit_ns; | |
426 | } | |
427 | ||
4f86d3a8 LB |
428 | /** |
429 | * cpuidle_install_idle_handler - installs the cpuidle idle loop handler | |
430 | */ | |
431 | void cpuidle_install_idle_handler(void) | |
432 | { | |
a0bfa137 | 433 | if (enabled_devices) { |
4f86d3a8 LB |
434 | /* Make sure all changes finished before we switch to new idle */ |
435 | smp_wmb(); | |
a0bfa137 | 436 | initialized = 1; |
4f86d3a8 LB |
437 | } |
438 | } | |
439 | ||
440 | /** | |
441 | * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler | |
442 | */ | |
443 | void cpuidle_uninstall_idle_handler(void) | |
444 | { | |
a0bfa137 LB |
445 | if (enabled_devices) { |
446 | initialized = 0; | |
2ed903c5 | 447 | wake_up_all_idle_cpus(); |
4f86d3a8 | 448 | } |
442bf3aa DL |
449 | |
450 | /* | |
451 | * Make sure external observers (such as the scheduler) | |
452 | * are done looking at pointed idle states. | |
453 | */ | |
454 | synchronize_rcu(); | |
4f86d3a8 LB |
455 | } |
456 | ||
457 | /** | |
458 | * cpuidle_pause_and_lock - temporarily disables CPUIDLE | |
459 | */ | |
460 | void cpuidle_pause_and_lock(void) | |
461 | { | |
462 | mutex_lock(&cpuidle_lock); | |
463 | cpuidle_uninstall_idle_handler(); | |
464 | } | |
465 | ||
466 | EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock); | |
467 | ||
468 | /** | |
469 | * cpuidle_resume_and_unlock - resumes CPUIDLE operation | |
470 | */ | |
471 | void cpuidle_resume_and_unlock(void) | |
472 | { | |
473 | cpuidle_install_idle_handler(); | |
474 | mutex_unlock(&cpuidle_lock); | |
475 | } | |
476 | ||
477 | EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); | |
478 | ||
8651f97b PM |
479 | /* Currently used in suspend/resume path to suspend cpuidle */ |
480 | void cpuidle_pause(void) | |
481 | { | |
482 | mutex_lock(&cpuidle_lock); | |
483 | cpuidle_uninstall_idle_handler(); | |
484 | mutex_unlock(&cpuidle_lock); | |
485 | } | |
486 | ||
487 | /* Currently used in suspend/resume path to resume cpuidle */ | |
488 | void cpuidle_resume(void) | |
489 | { | |
490 | mutex_lock(&cpuidle_lock); | |
491 | cpuidle_install_idle_handler(); | |
492 | mutex_unlock(&cpuidle_lock); | |
493 | } | |
494 | ||
4f86d3a8 LB |
495 | /** |
496 | * cpuidle_enable_device - enables idle PM for a CPU | |
497 | * @dev: the CPU | |
498 | * | |
499 | * This function must be called between cpuidle_pause_and_lock and | |
500 | * cpuidle_resume_and_unlock when used externally. | |
501 | */ | |
502 | int cpuidle_enable_device(struct cpuidle_device *dev) | |
503 | { | |
5df0aa73 | 504 | int ret; |
bf4d1b5d | 505 | struct cpuidle_driver *drv; |
4f86d3a8 | 506 | |
1b0a0e9a SB |
507 | if (!dev) |
508 | return -EINVAL; | |
509 | ||
4f86d3a8 LB |
510 | if (dev->enabled) |
511 | return 0; | |
bf4d1b5d | 512 | |
e7b06a09 GJ |
513 | if (!cpuidle_curr_governor) |
514 | return -EIO; | |
515 | ||
bf4d1b5d DL |
516 | drv = cpuidle_get_cpu_driver(dev); |
517 | ||
e7b06a09 | 518 | if (!drv) |
4f86d3a8 | 519 | return -EIO; |
bf4d1b5d | 520 | |
10b9d3f8 DL |
521 | if (!dev->registered) |
522 | return -EINVAL; | |
523 | ||
bf4d1b5d DL |
524 | ret = cpuidle_add_device_sysfs(dev); |
525 | if (ret) | |
4f86d3a8 LB |
526 | return ret; |
527 | ||
3fc74bd8 GJ |
528 | if (cpuidle_curr_governor->enable) { |
529 | ret = cpuidle_curr_governor->enable(drv, dev); | |
530 | if (ret) | |
531 | goto fail_sysfs; | |
532 | } | |
4f86d3a8 | 533 | |
4f86d3a8 LB |
534 | smp_wmb(); |
535 | ||
536 | dev->enabled = 1; | |
537 | ||
538 | enabled_devices++; | |
539 | return 0; | |
540 | ||
541 | fail_sysfs: | |
bf4d1b5d | 542 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
543 | |
544 | return ret; | |
545 | } | |
546 | ||
547 | EXPORT_SYMBOL_GPL(cpuidle_enable_device); | |
548 | ||
549 | /** | |
550 | * cpuidle_disable_device - disables idle PM for a CPU | |
551 | * @dev: the CPU | |
552 | * | |
553 | * This function must be called between cpuidle_pause_and_lock and | |
554 | * cpuidle_resume_and_unlock when used externally. | |
555 | */ | |
556 | void cpuidle_disable_device(struct cpuidle_device *dev) | |
557 | { | |
bf4d1b5d DL |
558 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
559 | ||
cf31cd1a | 560 | if (!dev || !dev->enabled) |
4f86d3a8 | 561 | return; |
bf4d1b5d DL |
562 | |
563 | if (!drv || !cpuidle_curr_governor) | |
4f86d3a8 LB |
564 | return; |
565 | ||
566 | dev->enabled = 0; | |
567 | ||
568 | if (cpuidle_curr_governor->disable) | |
bf4d1b5d | 569 | cpuidle_curr_governor->disable(drv, dev); |
4f86d3a8 | 570 | |
bf4d1b5d | 571 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
572 | enabled_devices--; |
573 | } | |
574 | ||
575 | EXPORT_SYMBOL_GPL(cpuidle_disable_device); | |
576 | ||
f6bb51a5 DL |
577 | static void __cpuidle_unregister_device(struct cpuidle_device *dev) |
578 | { | |
579 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); | |
580 | ||
581 | list_del(&dev->device_list); | |
582 | per_cpu(cpuidle_devices, dev->cpu) = NULL; | |
583 | module_put(drv->owner); | |
c998c078 DG |
584 | |
585 | dev->registered = 0; | |
f6bb51a5 DL |
586 | } |
587 | ||
267d4bf8 | 588 | static void __cpuidle_device_init(struct cpuidle_device *dev) |
5df0aa73 DL |
589 | { |
590 | memset(dev->states_usage, 0, sizeof(dev->states_usage)); | |
c1d51f68 | 591 | dev->last_residency_ns = 0; |
6f9b83ac | 592 | dev->next_hrtimer = 0; |
5df0aa73 DL |
593 | } |
594 | ||
4f86d3a8 | 595 | /** |
dcb84f33 VP |
596 | * __cpuidle_register_device - internal register function called before register |
597 | * and enable routines | |
4f86d3a8 | 598 | * @dev: the cpu |
dcb84f33 VP |
599 | * |
600 | * cpuidle_lock mutex must be held before this is called | |
4f86d3a8 | 601 | */ |
dcb84f33 | 602 | static int __cpuidle_register_device(struct cpuidle_device *dev) |
4f86d3a8 | 603 | { |
bf4d1b5d | 604 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
99e98d3f | 605 | int i, ret; |
4f86d3a8 | 606 | |
bf4d1b5d | 607 | if (!try_module_get(drv->owner)) |
4f86d3a8 LB |
608 | return -EINVAL; |
609 | ||
75a80267 | 610 | for (i = 0; i < drv->state_count; i++) { |
ba1e78a1 | 611 | if (drv->states[i].flags & CPUIDLE_FLAG_UNUSABLE) |
99e98d3f RW |
612 | dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_DRIVER; |
613 | ||
75a80267 RW |
614 | if (drv->states[i].flags & CPUIDLE_FLAG_OFF) |
615 | dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_USER; | |
616 | } | |
617 | ||
4f86d3a8 LB |
618 | per_cpu(cpuidle_devices, dev->cpu) = dev; |
619 | list_add(&dev->device_list, &cpuidle_detected_devices); | |
4f86d3a8 | 620 | |
4126c019 | 621 | ret = cpuidle_coupled_register_device(dev); |
47182668 | 622 | if (ret) |
f6bb51a5 | 623 | __cpuidle_unregister_device(dev); |
47182668 VK |
624 | else |
625 | dev->registered = 1; | |
4f86d3a8 | 626 | |
47182668 | 627 | return ret; |
dcb84f33 VP |
628 | } |
629 | ||
630 | /** | |
631 | * cpuidle_register_device - registers a CPU's idle PM feature | |
632 | * @dev: the cpu | |
633 | */ | |
634 | int cpuidle_register_device(struct cpuidle_device *dev) | |
635 | { | |
c878a52d | 636 | int ret = -EBUSY; |
dcb84f33 | 637 | |
1b0a0e9a SB |
638 | if (!dev) |
639 | return -EINVAL; | |
640 | ||
dcb84f33 VP |
641 | mutex_lock(&cpuidle_lock); |
642 | ||
c878a52d DL |
643 | if (dev->registered) |
644 | goto out_unlock; | |
645 | ||
267d4bf8 | 646 | __cpuidle_device_init(dev); |
5df0aa73 | 647 | |
f6bb51a5 DL |
648 | ret = __cpuidle_register_device(dev); |
649 | if (ret) | |
650 | goto out_unlock; | |
651 | ||
652 | ret = cpuidle_add_sysfs(dev); | |
653 | if (ret) | |
654 | goto out_unregister; | |
dcb84f33 | 655 | |
10b9d3f8 | 656 | ret = cpuidle_enable_device(dev); |
f6bb51a5 DL |
657 | if (ret) |
658 | goto out_sysfs; | |
10b9d3f8 | 659 | |
4f86d3a8 LB |
660 | cpuidle_install_idle_handler(); |
661 | ||
f6bb51a5 | 662 | out_unlock: |
4f86d3a8 LB |
663 | mutex_unlock(&cpuidle_lock); |
664 | ||
f6bb51a5 DL |
665 | return ret; |
666 | ||
667 | out_sysfs: | |
668 | cpuidle_remove_sysfs(dev); | |
669 | out_unregister: | |
670 | __cpuidle_unregister_device(dev); | |
671 | goto out_unlock; | |
4f86d3a8 LB |
672 | } |
673 | ||
674 | EXPORT_SYMBOL_GPL(cpuidle_register_device); | |
675 | ||
676 | /** | |
677 | * cpuidle_unregister_device - unregisters a CPU's idle PM feature | |
678 | * @dev: the cpu | |
679 | */ | |
680 | void cpuidle_unregister_device(struct cpuidle_device *dev) | |
681 | { | |
813e8e3d | 682 | if (!dev || dev->registered == 0) |
dcb84f33 VP |
683 | return; |
684 | ||
4f86d3a8 LB |
685 | cpuidle_pause_and_lock(); |
686 | ||
687 | cpuidle_disable_device(dev); | |
688 | ||
1aef40e2 | 689 | cpuidle_remove_sysfs(dev); |
f6bb51a5 DL |
690 | |
691 | __cpuidle_unregister_device(dev); | |
4f86d3a8 | 692 | |
4126c019 CC |
693 | cpuidle_coupled_unregister_device(dev); |
694 | ||
4f86d3a8 | 695 | cpuidle_resume_and_unlock(); |
4f86d3a8 LB |
696 | } |
697 | ||
698 | EXPORT_SYMBOL_GPL(cpuidle_unregister_device); | |
699 | ||
1c192d04 | 700 | /** |
4c637b21 DL |
701 | * cpuidle_unregister: unregister a driver and the devices. This function |
702 | * can be used only if the driver has been previously registered through | |
703 | * the cpuidle_register function. | |
704 | * | |
705 | * @drv: a valid pointer to a struct cpuidle_driver | |
706 | */ | |
707 | void cpuidle_unregister(struct cpuidle_driver *drv) | |
708 | { | |
709 | int cpu; | |
710 | struct cpuidle_device *device; | |
711 | ||
82467a5a | 712 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
713 | device = &per_cpu(cpuidle_dev, cpu); |
714 | cpuidle_unregister_device(device); | |
715 | } | |
716 | ||
717 | cpuidle_unregister_driver(drv); | |
718 | } | |
719 | EXPORT_SYMBOL_GPL(cpuidle_unregister); | |
720 | ||
721 | /** | |
722 | * cpuidle_register: registers the driver and the cpu devices with the | |
723 | * coupled_cpus passed as parameter. This function is used for all common | |
724 | * initialization pattern there are in the arch specific drivers. The | |
725 | * devices is globally defined in this file. | |
726 | * | |
727 | * @drv : a valid pointer to a struct cpuidle_driver | |
728 | * @coupled_cpus: a cpumask for the coupled states | |
729 | * | |
730 | * Returns 0 on success, < 0 otherwise | |
731 | */ | |
732 | int cpuidle_register(struct cpuidle_driver *drv, | |
733 | const struct cpumask *const coupled_cpus) | |
734 | { | |
735 | int ret, cpu; | |
736 | struct cpuidle_device *device; | |
737 | ||
738 | ret = cpuidle_register_driver(drv); | |
739 | if (ret) { | |
740 | pr_err("failed to register cpuidle driver\n"); | |
741 | return ret; | |
742 | } | |
743 | ||
82467a5a | 744 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
745 | device = &per_cpu(cpuidle_dev, cpu); |
746 | device->cpu = cpu; | |
747 | ||
748 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED | |
749 | /* | |
caf4a36e | 750 | * On multiplatform for ARM, the coupled idle states could be |
4c637b21 DL |
751 | * enabled in the kernel even if the cpuidle driver does not |
752 | * use it. Note, coupled_cpus is a struct copy. | |
753 | */ | |
754 | if (coupled_cpus) | |
755 | device->coupled_cpus = *coupled_cpus; | |
756 | #endif | |
757 | ret = cpuidle_register_device(device); | |
758 | if (!ret) | |
759 | continue; | |
760 | ||
761 | pr_err("Failed to register cpuidle device for cpu%d\n", cpu); | |
762 | ||
763 | cpuidle_unregister(drv); | |
764 | break; | |
765 | } | |
766 | ||
767 | return ret; | |
768 | } | |
769 | EXPORT_SYMBOL_GPL(cpuidle_register); | |
770 | ||
4f86d3a8 LB |
771 | /** |
772 | * cpuidle_init - core initializer | |
773 | */ | |
774 | static int __init cpuidle_init(void) | |
775 | { | |
62027aea LB |
776 | if (cpuidle_disabled()) |
777 | return -ENODEV; | |
778 | ||
3a4a0042 | 779 | return cpuidle_add_interface(cpu_subsys.dev_root); |
4f86d3a8 LB |
780 | } |
781 | ||
62027aea | 782 | module_param(off, int, 0444); |
61cb5758 | 783 | module_param_string(governor, param_governor, CPUIDLE_NAME_LEN, 0444); |
4f86d3a8 | 784 | core_initcall(cpuidle_init); |