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> |
a01353cf | 17 | #include <linux/sched/idle.h> |
4f86d3a8 | 18 | #include <linux/notifier.h> |
e8db0be1 | 19 | #include <linux/pm_qos.h> |
4f86d3a8 LB |
20 | #include <linux/cpu.h> |
21 | #include <linux/cpuidle.h> | |
9a0b8415 | 22 | #include <linux/ktime.h> |
2e94d1f7 | 23 | #include <linux/hrtimer.h> |
884b17e1 | 24 | #include <linux/module.h> |
38106313 | 25 | #include <linux/suspend.h> |
124cf911 | 26 | #include <linux/tick.h> |
bf9282dc | 27 | #include <linux/mmu_context.h> |
e67198cc | 28 | #include <linux/context_tracking.h> |
288f023e | 29 | #include <trace/events/power.h> |
4f86d3a8 LB |
30 | |
31 | #include "cpuidle.h" | |
32 | ||
33 | DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices); | |
4c637b21 | 34 | DEFINE_PER_CPU(struct cpuidle_device, cpuidle_dev); |
4f86d3a8 LB |
35 | |
36 | DEFINE_MUTEX(cpuidle_lock); | |
37 | LIST_HEAD(cpuidle_detected_devices); | |
4f86d3a8 LB |
38 | |
39 | static int enabled_devices; | |
62027aea | 40 | static int off __read_mostly; |
a0bfa137 | 41 | static int initialized __read_mostly; |
62027aea LB |
42 | |
43 | int cpuidle_disabled(void) | |
44 | { | |
45 | return off; | |
46 | } | |
d91ee586 LB |
47 | void disable_cpuidle(void) |
48 | { | |
49 | off = 1; | |
50 | } | |
4f86d3a8 | 51 | |
ef2b22ac RW |
52 | bool cpuidle_not_available(struct cpuidle_driver *drv, |
53 | struct cpuidle_device *dev) | |
31a34090 RW |
54 | { |
55 | return off || !initialized || !drv || !dev || !dev->enabled; | |
56 | } | |
57 | ||
1a022e3f BO |
58 | /** |
59 | * cpuidle_play_dead - cpu off-lining | |
60 | * | |
ee01e663 | 61 | * Returns in case of an error or no driver |
1a022e3f BO |
62 | */ |
63 | int cpuidle_play_dead(void) | |
64 | { | |
65 | struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); | |
bf4d1b5d | 66 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
8aef33a7 | 67 | int i; |
1a022e3f | 68 | |
ee01e663 TK |
69 | if (!drv) |
70 | return -ENODEV; | |
71 | ||
1a022e3f | 72 | /* Find lowest-power state that supports long-term idle */ |
7d51d979 | 73 | for (i = drv->state_count - 1; i >= 0; i--) |
8aef33a7 DL |
74 | if (drv->states[i].enter_dead) |
75 | return drv->states[i].enter_dead(dev, i); | |
1a022e3f BO |
76 | |
77 | return -ENODEV; | |
78 | } | |
79 | ||
ef2b22ac | 80 | static int find_deepest_state(struct cpuidle_driver *drv, |
0d94039f | 81 | struct cpuidle_device *dev, |
c1d51f68 | 82 | u64 max_latency_ns, |
0d94039f | 83 | unsigned int forbidden_flags, |
28ba086e | 84 | bool s2idle) |
a6220fc1 | 85 | { |
c1d51f68 | 86 | u64 latency_req = 0; |
51164251 | 87 | int i, ret = 0; |
a6220fc1 | 88 | |
51164251 | 89 | for (i = 1; i < drv->state_count; i++) { |
a6220fc1 | 90 | struct cpuidle_state *s = &drv->states[i]; |
a6220fc1 | 91 | |
99e98d3f | 92 | if (dev->states_usage[i].disable || |
c1d51f68 RW |
93 | s->exit_latency_ns <= latency_req || |
94 | s->exit_latency_ns > max_latency_ns || | |
99e98d3f RW |
95 | (s->flags & forbidden_flags) || |
96 | (s2idle && !s->enter_s2idle)) | |
a6220fc1 RW |
97 | continue; |
98 | ||
c1d51f68 | 99 | latency_req = s->exit_latency_ns; |
a6220fc1 RW |
100 | ret = i; |
101 | } | |
102 | return ret; | |
103 | } | |
104 | ||
0e7414b7 | 105 | /** |
c55b51a0 DL |
106 | * cpuidle_use_deepest_state - Set/unset governor override mode. |
107 | * @latency_limit_ns: Idle state exit latency limit (or no override if 0). | |
0e7414b7 | 108 | * |
c55b51a0 DL |
109 | * If @latency_limit_ns is nonzero, set the current CPU to use the deepest idle |
110 | * state with exit latency within @latency_limit_ns (override governors going | |
111 | * forward), or do not override governors if it is zero. | |
0e7414b7 | 112 | */ |
c55b51a0 | 113 | void cpuidle_use_deepest_state(u64 latency_limit_ns) |
bb8313b6 JP |
114 | { |
115 | struct cpuidle_device *dev; | |
116 | ||
117 | preempt_disable(); | |
118 | dev = cpuidle_get_device(); | |
41dc750e | 119 | if (dev) |
c55b51a0 | 120 | dev->forced_idle_latency_limit_ns = latency_limit_ns; |
bb8313b6 JP |
121 | preempt_enable(); |
122 | } | |
123 | ||
ef2b22ac RW |
124 | /** |
125 | * cpuidle_find_deepest_state - Find the deepest available idle state. | |
126 | * @drv: cpuidle driver for the given CPU. | |
127 | * @dev: cpuidle device for the given CPU. | |
cefb9409 BG |
128 | * @latency_limit_ns: Idle state exit latency limit |
129 | * | |
130 | * Return: the index of the deepest available idle state. | |
ef2b22ac RW |
131 | */ |
132 | int cpuidle_find_deepest_state(struct cpuidle_driver *drv, | |
5aa9ba63 DL |
133 | struct cpuidle_device *dev, |
134 | u64 latency_limit_ns) | |
ef2b22ac | 135 | { |
5aa9ba63 | 136 | return find_deepest_state(drv, dev, latency_limit_ns, 0, false); |
ef2b22ac RW |
137 | } |
138 | ||
bb8313b6 | 139 | #ifdef CONFIG_SUSPEND |
17cc2b55 PZ |
140 | static noinstr void enter_s2idle_proper(struct cpuidle_driver *drv, |
141 | struct cpuidle_device *dev, int index) | |
124cf911 | 142 | { |
8747f202 | 143 | struct cpuidle_state *target_state = &drv->states[index]; |
17cc2b55 PZ |
144 | ktime_t time_start, time_end; |
145 | ||
146 | instrumentation_begin(); | |
64bdff69 | 147 | |
e6a15fa9 | 148 | time_start = ns_to_ktime(local_clock_noinstr()); |
64bdff69 | 149 | |
1098582a | 150 | tick_freeze(); |
124cf911 RW |
151 | /* |
152 | * The state used here cannot be a "coupled" one, because the "coupled" | |
153 | * cpuidle mechanism enables interrupts and doing that with timekeeping | |
154 | * suspended is generally unsafe. | |
155 | */ | |
63caae84 | 156 | stop_critical_timings(); |
17cc2b55 | 157 | if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) { |
a01353cf | 158 | ct_cpuidle_enter(); |
17cc2b55 PZ |
159 | /* Annotate away the indirect call */ |
160 | instrumentation_begin(); | |
161 | } | |
8747f202 | 162 | target_state->enter_s2idle(dev, drv, index); |
49d9c593 | 163 | if (WARN_ON_ONCE(!irqs_disabled())) |
a01353cf | 164 | raw_local_irq_disable(); |
17cc2b55 PZ |
165 | if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) { |
166 | instrumentation_end(); | |
a01353cf | 167 | ct_cpuidle_exit(); |
17cc2b55 | 168 | } |
1098582a | 169 | tick_unfreeze(); |
63caae84 | 170 | start_critical_timings(); |
64bdff69 | 171 | |
e6a15fa9 | 172 | time_end = ns_to_ktime(local_clock_noinstr()); |
64bdff69 RW |
173 | |
174 | dev->states_usage[index].s2idle_time += ktime_us_delta(time_end, time_start); | |
175 | dev->states_usage[index].s2idle_usage++; | |
17cc2b55 | 176 | instrumentation_end(); |
124cf911 RW |
177 | } |
178 | ||
38106313 | 179 | /** |
28ba086e | 180 | * cpuidle_enter_s2idle - Enter an idle state suitable for suspend-to-idle. |
ef2b22ac RW |
181 | * @drv: cpuidle driver for the given CPU. |
182 | * @dev: cpuidle device for the given CPU. | |
38106313 | 183 | * |
28ba086e | 184 | * If there are states with the ->enter_s2idle callback, find the deepest of |
ef2b22ac | 185 | * them and enter it with frozen tick. |
38106313 | 186 | */ |
28ba086e | 187 | int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
38106313 | 188 | { |
38106313 RW |
189 | int index; |
190 | ||
124cf911 | 191 | /* |
28ba086e | 192 | * Find the deepest state with ->enter_s2idle present, which guarantees |
124cf911 RW |
193 | * that interrupts won't be enabled when it exits and allows the tick to |
194 | * be frozen safely. | |
195 | */ | |
c1d51f68 | 196 | index = find_deepest_state(drv, dev, U64_MAX, 0, true); |
10e8b11e | 197 | if (index > 0) { |
28ba086e | 198 | enter_s2idle_proper(drv, dev, index); |
10e8b11e RW |
199 | local_irq_enable(); |
200 | } | |
ef2b22ac | 201 | return index; |
38106313 | 202 | } |
87e9b9f1 | 203 | #endif /* CONFIG_SUSPEND */ |
38106313 | 204 | |
56cfbf74 CC |
205 | /** |
206 | * cpuidle_enter_state - enter the state and update stats | |
207 | * @dev: cpuidle device for this cpu | |
208 | * @drv: cpuidle driver for this cpu | |
7312280b | 209 | * @index: index into the states table in @drv of the state to enter |
56cfbf74 | 210 | */ |
17cc2b55 PZ |
211 | noinstr int cpuidle_enter_state(struct cpuidle_device *dev, |
212 | struct cpuidle_driver *drv, | |
213 | int index) | |
56cfbf74 CC |
214 | { |
215 | int entered_state; | |
216 | ||
554c06ba | 217 | struct cpuidle_state *target_state = &drv->states[index]; |
df8d9eea | 218 | bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP); |
dbd1b8ea | 219 | ktime_t time_start, time_end; |
554c06ba | 220 | |
17cc2b55 PZ |
221 | instrumentation_begin(); |
222 | ||
df8d9eea RW |
223 | /* |
224 | * Tell the time framework to switch to a broadcast timer because our | |
225 | * local timer will be shut down. If a local timer is used from another | |
226 | * CPU as a broadcast timer, this call may fail if it is not available. | |
227 | */ | |
827a5aef | 228 | if (broadcast && tick_broadcast_enter()) { |
c1d51f68 | 229 | index = find_deepest_state(drv, dev, target_state->exit_latency_ns, |
0d94039f RW |
230 | CPUIDLE_FLAG_TIMER_STOP, false); |
231 | if (index < 0) { | |
232 | default_idle_call(); | |
233 | return -EBUSY; | |
234 | } | |
235 | target_state = &drv->states[index]; | |
f187851b | 236 | broadcast = false; |
827a5aef | 237 | } |
df8d9eea | 238 | |
bf9282dc | 239 | if (target_state->flags & CPUIDLE_FLAG_TLB_FLUSHED) |
7dbbc8f5 | 240 | leave_mm(); |
bf9282dc | 241 | |
faad3849 RW |
242 | /* Take note of the planned idle state. */ |
243 | sched_idle_set_state(target_state); | |
244 | ||
1098582a | 245 | trace_cpu_idle(index, dev->cpu); |
e6a15fa9 | 246 | time_start = ns_to_ktime(local_clock_noinstr()); |
554c06ba | 247 | |
63caae84 | 248 | stop_critical_timings(); |
17cc2b55 | 249 | if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) { |
a01353cf | 250 | ct_cpuidle_enter(); |
17cc2b55 PZ |
251 | /* Annotate away the indirect call */ |
252 | instrumentation_begin(); | |
253 | } | |
bb7b1125 | 254 | |
0e985e9d PZ |
255 | /* |
256 | * NOTE!! | |
257 | * | |
258 | * For cpuidle_state::enter() methods that do *NOT* set | |
259 | * CPUIDLE_FLAG_RCU_IDLE RCU will be disabled here and these functions | |
260 | * must be marked either noinstr or __cpuidle. | |
261 | * | |
262 | * For cpuidle_state::enter() methods that *DO* set | |
263 | * CPUIDLE_FLAG_RCU_IDLE this isn't required, but they must mark the | |
264 | * function calling ct_cpuidle_enter() as noinstr/__cpuidle and all | |
265 | * functions called within the RCU-idle region. | |
266 | */ | |
554c06ba | 267 | entered_state = target_state->enter(dev, drv, index); |
17cc2b55 | 268 | |
bb7b1125 PZ |
269 | if (WARN_ONCE(!irqs_disabled(), "%ps leaked IRQ state", target_state->enter)) |
270 | raw_local_irq_disable(); | |
271 | ||
17cc2b55 PZ |
272 | if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) { |
273 | instrumentation_end(); | |
a01353cf | 274 | ct_cpuidle_exit(); |
17cc2b55 | 275 | } |
63caae84 | 276 | start_critical_timings(); |
554c06ba | 277 | |
f9fccdb9 | 278 | sched_clock_idle_wakeup_event(); |
e6a15fa9 | 279 | time_end = ns_to_ktime(local_clock_noinstr()); |
1098582a | 280 | trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu); |
554c06ba | 281 | |
faad3849 RW |
282 | /* The cpu is no longer idle or about to enter idle. */ |
283 | sched_idle_set_state(NULL); | |
284 | ||
bb7b1125 | 285 | if (broadcast) |
df8d9eea | 286 | tick_broadcast_exit(); |
df8d9eea | 287 | |
e7387da5 | 288 | if (!cpuidle_state_is_coupled(drv, index)) |
0b89e9aa | 289 | local_irq_enable(); |
554c06ba | 290 | |
56cfbf74 | 291 | if (entered_state >= 0) { |
c1d51f68 | 292 | s64 diff, delay = drv->states[entered_state].exit_latency_ns; |
04dab58a RW |
293 | int i; |
294 | ||
7037b43e FL |
295 | /* |
296 | * Update cpuidle counters | |
297 | * This can be moved to within driver enter routine, | |
56cfbf74 CC |
298 | * but that results in multiple copies of same code. |
299 | */ | |
c1d51f68 | 300 | diff = ktime_sub(time_end, time_start); |
7037b43e | 301 | |
c1d51f68 RW |
302 | dev->last_residency_ns = diff; |
303 | dev->states_usage[entered_state].time_ns += diff; | |
56cfbf74 | 304 | dev->states_usage[entered_state].usage++; |
04dab58a | 305 | |
c1d51f68 | 306 | if (diff < drv->states[entered_state].target_residency_ns) { |
04dab58a | 307 | for (i = entered_state - 1; i >= 0; i--) { |
99e98d3f | 308 | if (dev->states_usage[i].disable) |
04dab58a RW |
309 | continue; |
310 | ||
311 | /* Shallower states are enabled, so update. */ | |
312 | dev->states_usage[entered_state].above++; | |
6ab4b199 | 313 | trace_cpu_idle_miss(dev->cpu, entered_state, false); |
04dab58a RW |
314 | break; |
315 | } | |
316 | } else if (diff > delay) { | |
317 | for (i = entered_state + 1; i < drv->state_count; i++) { | |
99e98d3f | 318 | if (dev->states_usage[i].disable) |
04dab58a RW |
319 | continue; |
320 | ||
321 | /* | |
322 | * Update if a deeper state would have been a | |
323 | * better match for the observed idle duration. | |
324 | */ | |
6ab4b199 | 325 | if (diff - delay >= drv->states[i].target_residency_ns) { |
04dab58a | 326 | dev->states_usage[entered_state].below++; |
6ab4b199 KP |
327 | trace_cpu_idle_miss(dev->cpu, entered_state, true); |
328 | } | |
04dab58a RW |
329 | |
330 | break; | |
331 | } | |
332 | } | |
56cfbf74 | 333 | } else { |
c1d51f68 | 334 | dev->last_residency_ns = 0; |
f49735f4 | 335 | dev->states_usage[index].rejected++; |
56cfbf74 CC |
336 | } |
337 | ||
17cc2b55 PZ |
338 | instrumentation_end(); |
339 | ||
56cfbf74 CC |
340 | return entered_state; |
341 | } | |
342 | ||
4f86d3a8 | 343 | /** |
907e30f1 DL |
344 | * cpuidle_select - ask the cpuidle framework to choose an idle state |
345 | * | |
346 | * @drv: the cpuidle driver | |
347 | * @dev: the cpuidle device | |
45f1ff59 | 348 | * @stop_tick: indication on whether or not to stop the tick |
4f86d3a8 | 349 | * |
51164251 | 350 | * Returns the index of the idle state. The return value must not be negative. |
45f1ff59 RW |
351 | * |
352 | * The memory location pointed to by @stop_tick is expected to be written the | |
353 | * 'false' boolean value if the scheduler tick should not be stopped before | |
354 | * entering the returned state. | |
4f86d3a8 | 355 | */ |
45f1ff59 RW |
356 | int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, |
357 | bool *stop_tick) | |
4f86d3a8 | 358 | { |
45f1ff59 | 359 | return cpuidle_curr_governor->select(drv, dev, stop_tick); |
907e30f1 | 360 | } |
ba8f20c2 | 361 | |
907e30f1 DL |
362 | /** |
363 | * cpuidle_enter - enter into the specified idle state | |
364 | * | |
365 | * @drv: the cpuidle driver tied with the cpu | |
366 | * @dev: the cpuidle device | |
367 | * @index: the index in the idle state table | |
368 | * | |
369 | * Returns the index in the idle state, < 0 in case of error. | |
370 | * The error code depends on the backend driver | |
371 | */ | |
372 | int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, | |
373 | int index) | |
374 | { | |
6f9b83ac UH |
375 | int ret = 0; |
376 | ||
377 | /* | |
378 | * Store the next hrtimer, which becomes either next tick or the next | |
379 | * timer event, whatever expires first. Additionally, to make this data | |
380 | * useful for consumers outside cpuidle, we rely on that the governor's | |
381 | * ->select() callback have decided, whether to stop the tick or not. | |
382 | */ | |
383 | WRITE_ONCE(dev->next_hrtimer, tick_nohz_get_next_hrtimer()); | |
384 | ||
4c1ed5a6 | 385 | if (cpuidle_state_is_coupled(drv, index)) |
6f9b83ac UH |
386 | ret = cpuidle_enter_state_coupled(dev, drv, index); |
387 | else | |
388 | ret = cpuidle_enter_state(dev, drv, index); | |
389 | ||
390 | WRITE_ONCE(dev->next_hrtimer, 0); | |
391 | return ret; | |
907e30f1 | 392 | } |
b60e6a0e | 393 | |
907e30f1 DL |
394 | /** |
395 | * cpuidle_reflect - tell the underlying governor what was the state | |
396 | * we were in | |
397 | * | |
398 | * @dev : the cpuidle device | |
399 | * @index: the index in the idle state table | |
400 | * | |
401 | */ | |
402 | void cpuidle_reflect(struct cpuidle_device *dev, int index) | |
403 | { | |
a802ea96 | 404 | if (cpuidle_curr_governor->reflect && index >= 0) |
907e30f1 | 405 | cpuidle_curr_governor->reflect(dev, index); |
4f86d3a8 LB |
406 | } |
407 | ||
7a25759e MG |
408 | /* |
409 | * Min polling interval of 10usec is a guess. It is assuming that | |
410 | * for most users, the time for a single ping-pong workload like | |
411 | * perf bench pipe would generally complete within 10usec but | |
412 | * this is hardware dependant. Actual time can be estimated with | |
413 | * | |
414 | * perf bench sched pipe -l 10000 | |
415 | * | |
416 | * Run multiple times to avoid cpufreq effects. | |
417 | */ | |
418 | #define CPUIDLE_POLL_MIN 10000 | |
419 | #define CPUIDLE_POLL_MAX (TICK_NSEC / 16) | |
420 | ||
259231a0 MT |
421 | /** |
422 | * cpuidle_poll_time - return amount of time to poll for, | |
423 | * governors can override dev->poll_limit_ns if necessary | |
424 | * | |
425 | * @drv: the cpuidle driver tied with the cpu | |
426 | * @dev: the cpuidle device | |
427 | * | |
428 | */ | |
4d627628 | 429 | __cpuidle u64 cpuidle_poll_time(struct cpuidle_driver *drv, |
259231a0 MT |
430 | struct cpuidle_device *dev) |
431 | { | |
432 | int i; | |
433 | u64 limit_ns; | |
434 | ||
7a25759e MG |
435 | BUILD_BUG_ON(CPUIDLE_POLL_MIN > CPUIDLE_POLL_MAX); |
436 | ||
259231a0 MT |
437 | if (dev->poll_limit_ns) |
438 | return dev->poll_limit_ns; | |
439 | ||
7a25759e | 440 | limit_ns = CPUIDLE_POLL_MAX; |
259231a0 | 441 | for (i = 1; i < drv->state_count; i++) { |
7a25759e MG |
442 | u64 state_limit; |
443 | ||
99e98d3f | 444 | if (dev->states_usage[i].disable) |
259231a0 MT |
445 | continue; |
446 | ||
7a25759e MG |
447 | state_limit = drv->states[i].target_residency_ns; |
448 | if (state_limit < CPUIDLE_POLL_MIN) | |
449 | continue; | |
450 | ||
451 | limit_ns = min_t(u64, state_limit, CPUIDLE_POLL_MAX); | |
36fcb429 | 452 | break; |
259231a0 MT |
453 | } |
454 | ||
455 | dev->poll_limit_ns = limit_ns; | |
456 | ||
457 | return dev->poll_limit_ns; | |
458 | } | |
459 | ||
4f86d3a8 LB |
460 | /** |
461 | * cpuidle_install_idle_handler - installs the cpuidle idle loop handler | |
462 | */ | |
463 | void cpuidle_install_idle_handler(void) | |
464 | { | |
a0bfa137 | 465 | if (enabled_devices) { |
4f86d3a8 LB |
466 | /* Make sure all changes finished before we switch to new idle */ |
467 | smp_wmb(); | |
a0bfa137 | 468 | initialized = 1; |
4f86d3a8 LB |
469 | } |
470 | } | |
471 | ||
472 | /** | |
473 | * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler | |
474 | */ | |
475 | void cpuidle_uninstall_idle_handler(void) | |
476 | { | |
a0bfa137 LB |
477 | if (enabled_devices) { |
478 | initialized = 0; | |
2ed903c5 | 479 | wake_up_all_idle_cpus(); |
4f86d3a8 | 480 | } |
442bf3aa DL |
481 | |
482 | /* | |
483 | * Make sure external observers (such as the scheduler) | |
484 | * are done looking at pointed idle states. | |
485 | */ | |
486 | synchronize_rcu(); | |
4f86d3a8 LB |
487 | } |
488 | ||
489 | /** | |
490 | * cpuidle_pause_and_lock - temporarily disables CPUIDLE | |
491 | */ | |
492 | void cpuidle_pause_and_lock(void) | |
493 | { | |
494 | mutex_lock(&cpuidle_lock); | |
495 | cpuidle_uninstall_idle_handler(); | |
496 | } | |
497 | ||
498 | EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock); | |
499 | ||
500 | /** | |
501 | * cpuidle_resume_and_unlock - resumes CPUIDLE operation | |
502 | */ | |
503 | void cpuidle_resume_and_unlock(void) | |
504 | { | |
505 | cpuidle_install_idle_handler(); | |
506 | mutex_unlock(&cpuidle_lock); | |
507 | } | |
508 | ||
509 | EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); | |
510 | ||
8651f97b PM |
511 | /* Currently used in suspend/resume path to suspend cpuidle */ |
512 | void cpuidle_pause(void) | |
513 | { | |
514 | mutex_lock(&cpuidle_lock); | |
515 | cpuidle_uninstall_idle_handler(); | |
516 | mutex_unlock(&cpuidle_lock); | |
517 | } | |
518 | ||
519 | /* Currently used in suspend/resume path to resume cpuidle */ | |
520 | void cpuidle_resume(void) | |
521 | { | |
522 | mutex_lock(&cpuidle_lock); | |
523 | cpuidle_install_idle_handler(); | |
524 | mutex_unlock(&cpuidle_lock); | |
525 | } | |
526 | ||
4f86d3a8 LB |
527 | /** |
528 | * cpuidle_enable_device - enables idle PM for a CPU | |
529 | * @dev: the CPU | |
530 | * | |
531 | * This function must be called between cpuidle_pause_and_lock and | |
532 | * cpuidle_resume_and_unlock when used externally. | |
533 | */ | |
534 | int cpuidle_enable_device(struct cpuidle_device *dev) | |
535 | { | |
5df0aa73 | 536 | int ret; |
bf4d1b5d | 537 | struct cpuidle_driver *drv; |
4f86d3a8 | 538 | |
1b0a0e9a SB |
539 | if (!dev) |
540 | return -EINVAL; | |
541 | ||
4f86d3a8 LB |
542 | if (dev->enabled) |
543 | return 0; | |
bf4d1b5d | 544 | |
e7b06a09 GJ |
545 | if (!cpuidle_curr_governor) |
546 | return -EIO; | |
547 | ||
bf4d1b5d DL |
548 | drv = cpuidle_get_cpu_driver(dev); |
549 | ||
e7b06a09 | 550 | if (!drv) |
4f86d3a8 | 551 | return -EIO; |
bf4d1b5d | 552 | |
10b9d3f8 DL |
553 | if (!dev->registered) |
554 | return -EINVAL; | |
555 | ||
bf4d1b5d DL |
556 | ret = cpuidle_add_device_sysfs(dev); |
557 | if (ret) | |
4f86d3a8 LB |
558 | return ret; |
559 | ||
3fc74bd8 GJ |
560 | if (cpuidle_curr_governor->enable) { |
561 | ret = cpuidle_curr_governor->enable(drv, dev); | |
562 | if (ret) | |
563 | goto fail_sysfs; | |
564 | } | |
4f86d3a8 | 565 | |
4f86d3a8 LB |
566 | smp_wmb(); |
567 | ||
568 | dev->enabled = 1; | |
569 | ||
570 | enabled_devices++; | |
571 | return 0; | |
572 | ||
573 | fail_sysfs: | |
bf4d1b5d | 574 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
575 | |
576 | return ret; | |
577 | } | |
578 | ||
579 | EXPORT_SYMBOL_GPL(cpuidle_enable_device); | |
580 | ||
581 | /** | |
582 | * cpuidle_disable_device - disables idle PM for a CPU | |
583 | * @dev: the CPU | |
584 | * | |
585 | * This function must be called between cpuidle_pause_and_lock and | |
586 | * cpuidle_resume_and_unlock when used externally. | |
587 | */ | |
588 | void cpuidle_disable_device(struct cpuidle_device *dev) | |
589 | { | |
bf4d1b5d DL |
590 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
591 | ||
cf31cd1a | 592 | if (!dev || !dev->enabled) |
4f86d3a8 | 593 | return; |
bf4d1b5d DL |
594 | |
595 | if (!drv || !cpuidle_curr_governor) | |
4f86d3a8 LB |
596 | return; |
597 | ||
598 | dev->enabled = 0; | |
599 | ||
600 | if (cpuidle_curr_governor->disable) | |
bf4d1b5d | 601 | cpuidle_curr_governor->disable(drv, dev); |
4f86d3a8 | 602 | |
bf4d1b5d | 603 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
604 | enabled_devices--; |
605 | } | |
606 | ||
607 | EXPORT_SYMBOL_GPL(cpuidle_disable_device); | |
608 | ||
f6bb51a5 DL |
609 | static void __cpuidle_unregister_device(struct cpuidle_device *dev) |
610 | { | |
611 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); | |
612 | ||
613 | list_del(&dev->device_list); | |
614 | per_cpu(cpuidle_devices, dev->cpu) = NULL; | |
615 | module_put(drv->owner); | |
c998c078 DG |
616 | |
617 | dev->registered = 0; | |
f6bb51a5 DL |
618 | } |
619 | ||
267d4bf8 | 620 | static void __cpuidle_device_init(struct cpuidle_device *dev) |
5df0aa73 DL |
621 | { |
622 | memset(dev->states_usage, 0, sizeof(dev->states_usage)); | |
c1d51f68 | 623 | dev->last_residency_ns = 0; |
6f9b83ac | 624 | dev->next_hrtimer = 0; |
5df0aa73 DL |
625 | } |
626 | ||
4f86d3a8 | 627 | /** |
dcb84f33 VP |
628 | * __cpuidle_register_device - internal register function called before register |
629 | * and enable routines | |
4f86d3a8 | 630 | * @dev: the cpu |
dcb84f33 VP |
631 | * |
632 | * cpuidle_lock mutex must be held before this is called | |
4f86d3a8 | 633 | */ |
dcb84f33 | 634 | static int __cpuidle_register_device(struct cpuidle_device *dev) |
4f86d3a8 | 635 | { |
bf4d1b5d | 636 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
99e98d3f | 637 | int i, ret; |
4f86d3a8 | 638 | |
bf4d1b5d | 639 | if (!try_module_get(drv->owner)) |
4f86d3a8 LB |
640 | return -EINVAL; |
641 | ||
75a80267 | 642 | for (i = 0; i < drv->state_count; i++) { |
ba1e78a1 | 643 | if (drv->states[i].flags & CPUIDLE_FLAG_UNUSABLE) |
99e98d3f RW |
644 | dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_DRIVER; |
645 | ||
75a80267 RW |
646 | if (drv->states[i].flags & CPUIDLE_FLAG_OFF) |
647 | dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_USER; | |
648 | } | |
649 | ||
4f86d3a8 LB |
650 | per_cpu(cpuidle_devices, dev->cpu) = dev; |
651 | list_add(&dev->device_list, &cpuidle_detected_devices); | |
4f86d3a8 | 652 | |
4126c019 | 653 | ret = cpuidle_coupled_register_device(dev); |
47182668 | 654 | if (ret) |
f6bb51a5 | 655 | __cpuidle_unregister_device(dev); |
47182668 VK |
656 | else |
657 | dev->registered = 1; | |
4f86d3a8 | 658 | |
47182668 | 659 | return ret; |
dcb84f33 VP |
660 | } |
661 | ||
662 | /** | |
663 | * cpuidle_register_device - registers a CPU's idle PM feature | |
664 | * @dev: the cpu | |
665 | */ | |
666 | int cpuidle_register_device(struct cpuidle_device *dev) | |
667 | { | |
c878a52d | 668 | int ret = -EBUSY; |
dcb84f33 | 669 | |
1b0a0e9a SB |
670 | if (!dev) |
671 | return -EINVAL; | |
672 | ||
dcb84f33 VP |
673 | mutex_lock(&cpuidle_lock); |
674 | ||
c878a52d DL |
675 | if (dev->registered) |
676 | goto out_unlock; | |
677 | ||
267d4bf8 | 678 | __cpuidle_device_init(dev); |
5df0aa73 | 679 | |
f6bb51a5 DL |
680 | ret = __cpuidle_register_device(dev); |
681 | if (ret) | |
682 | goto out_unlock; | |
683 | ||
684 | ret = cpuidle_add_sysfs(dev); | |
685 | if (ret) | |
686 | goto out_unregister; | |
dcb84f33 | 687 | |
10b9d3f8 | 688 | ret = cpuidle_enable_device(dev); |
f6bb51a5 DL |
689 | if (ret) |
690 | goto out_sysfs; | |
10b9d3f8 | 691 | |
4f86d3a8 LB |
692 | cpuidle_install_idle_handler(); |
693 | ||
f6bb51a5 | 694 | out_unlock: |
4f86d3a8 LB |
695 | mutex_unlock(&cpuidle_lock); |
696 | ||
f6bb51a5 DL |
697 | return ret; |
698 | ||
699 | out_sysfs: | |
700 | cpuidle_remove_sysfs(dev); | |
701 | out_unregister: | |
702 | __cpuidle_unregister_device(dev); | |
703 | goto out_unlock; | |
4f86d3a8 LB |
704 | } |
705 | ||
706 | EXPORT_SYMBOL_GPL(cpuidle_register_device); | |
707 | ||
708 | /** | |
709 | * cpuidle_unregister_device - unregisters a CPU's idle PM feature | |
710 | * @dev: the cpu | |
711 | */ | |
712 | void cpuidle_unregister_device(struct cpuidle_device *dev) | |
713 | { | |
813e8e3d | 714 | if (!dev || dev->registered == 0) |
dcb84f33 VP |
715 | return; |
716 | ||
4f86d3a8 LB |
717 | cpuidle_pause_and_lock(); |
718 | ||
719 | cpuidle_disable_device(dev); | |
720 | ||
1aef40e2 | 721 | cpuidle_remove_sysfs(dev); |
f6bb51a5 DL |
722 | |
723 | __cpuidle_unregister_device(dev); | |
4f86d3a8 | 724 | |
4126c019 CC |
725 | cpuidle_coupled_unregister_device(dev); |
726 | ||
4f86d3a8 | 727 | cpuidle_resume_and_unlock(); |
4f86d3a8 LB |
728 | } |
729 | ||
730 | EXPORT_SYMBOL_GPL(cpuidle_unregister_device); | |
731 | ||
1c192d04 | 732 | /** |
4c637b21 DL |
733 | * cpuidle_unregister: unregister a driver and the devices. This function |
734 | * can be used only if the driver has been previously registered through | |
735 | * the cpuidle_register function. | |
736 | * | |
737 | * @drv: a valid pointer to a struct cpuidle_driver | |
738 | */ | |
739 | void cpuidle_unregister(struct cpuidle_driver *drv) | |
740 | { | |
741 | int cpu; | |
742 | struct cpuidle_device *device; | |
743 | ||
82467a5a | 744 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
745 | device = &per_cpu(cpuidle_dev, cpu); |
746 | cpuidle_unregister_device(device); | |
747 | } | |
748 | ||
749 | cpuidle_unregister_driver(drv); | |
750 | } | |
751 | EXPORT_SYMBOL_GPL(cpuidle_unregister); | |
752 | ||
753 | /** | |
754 | * cpuidle_register: registers the driver and the cpu devices with the | |
755 | * coupled_cpus passed as parameter. This function is used for all common | |
756 | * initialization pattern there are in the arch specific drivers. The | |
757 | * devices is globally defined in this file. | |
758 | * | |
759 | * @drv : a valid pointer to a struct cpuidle_driver | |
760 | * @coupled_cpus: a cpumask for the coupled states | |
761 | * | |
762 | * Returns 0 on success, < 0 otherwise | |
763 | */ | |
764 | int cpuidle_register(struct cpuidle_driver *drv, | |
765 | const struct cpumask *const coupled_cpus) | |
766 | { | |
767 | int ret, cpu; | |
768 | struct cpuidle_device *device; | |
769 | ||
770 | ret = cpuidle_register_driver(drv); | |
771 | if (ret) { | |
772 | pr_err("failed to register cpuidle driver\n"); | |
773 | return ret; | |
774 | } | |
775 | ||
82467a5a | 776 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
777 | device = &per_cpu(cpuidle_dev, cpu); |
778 | device->cpu = cpu; | |
779 | ||
780 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED | |
781 | /* | |
caf4a36e | 782 | * On multiplatform for ARM, the coupled idle states could be |
4c637b21 DL |
783 | * enabled in the kernel even if the cpuidle driver does not |
784 | * use it. Note, coupled_cpus is a struct copy. | |
785 | */ | |
786 | if (coupled_cpus) | |
787 | device->coupled_cpus = *coupled_cpus; | |
788 | #endif | |
789 | ret = cpuidle_register_device(device); | |
790 | if (!ret) | |
791 | continue; | |
792 | ||
793 | pr_err("Failed to register cpuidle device for cpu%d\n", cpu); | |
794 | ||
795 | cpuidle_unregister(drv); | |
796 | break; | |
797 | } | |
798 | ||
799 | return ret; | |
800 | } | |
801 | EXPORT_SYMBOL_GPL(cpuidle_register); | |
802 | ||
4f86d3a8 LB |
803 | /** |
804 | * cpuidle_init - core initializer | |
805 | */ | |
806 | static int __init cpuidle_init(void) | |
807 | { | |
62027aea LB |
808 | if (cpuidle_disabled()) |
809 | return -ENODEV; | |
810 | ||
bf6479db | 811 | return cpuidle_add_interface(); |
4f86d3a8 LB |
812 | } |
813 | ||
62027aea | 814 | module_param(off, int, 0444); |
61cb5758 | 815 | module_param_string(governor, param_governor, CPUIDLE_NAME_LEN, 0444); |
4f86d3a8 | 816 | core_initcall(cpuidle_init); |