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> | |
15 | #include <linux/notifier.h> | |
e8db0be1 | 16 | #include <linux/pm_qos.h> |
4f86d3a8 LB |
17 | #include <linux/cpu.h> |
18 | #include <linux/cpuidle.h> | |
9a0b8415 | 19 | #include <linux/ktime.h> |
2e94d1f7 | 20 | #include <linux/hrtimer.h> |
884b17e1 | 21 | #include <linux/module.h> |
288f023e | 22 | #include <trace/events/power.h> |
4f86d3a8 LB |
23 | |
24 | #include "cpuidle.h" | |
25 | ||
26 | DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices); | |
4c637b21 | 27 | DEFINE_PER_CPU(struct cpuidle_device, cpuidle_dev); |
4f86d3a8 LB |
28 | |
29 | DEFINE_MUTEX(cpuidle_lock); | |
30 | LIST_HEAD(cpuidle_detected_devices); | |
4f86d3a8 LB |
31 | |
32 | static int enabled_devices; | |
62027aea | 33 | static int off __read_mostly; |
a0bfa137 | 34 | static int initialized __read_mostly; |
62027aea LB |
35 | |
36 | int cpuidle_disabled(void) | |
37 | { | |
38 | return off; | |
39 | } | |
d91ee586 LB |
40 | void disable_cpuidle(void) |
41 | { | |
42 | off = 1; | |
43 | } | |
4f86d3a8 | 44 | |
1a022e3f BO |
45 | /** |
46 | * cpuidle_play_dead - cpu off-lining | |
47 | * | |
ee01e663 | 48 | * Returns in case of an error or no driver |
1a022e3f BO |
49 | */ |
50 | int cpuidle_play_dead(void) | |
51 | { | |
52 | struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); | |
bf4d1b5d | 53 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
8aef33a7 | 54 | int i; |
1a022e3f | 55 | |
ee01e663 TK |
56 | if (!drv) |
57 | return -ENODEV; | |
58 | ||
1a022e3f | 59 | /* Find lowest-power state that supports long-term idle */ |
8aef33a7 DL |
60 | for (i = drv->state_count - 1; i >= CPUIDLE_DRIVER_STATE_START; i--) |
61 | if (drv->states[i].enter_dead) | |
62 | return drv->states[i].enter_dead(dev, i); | |
1a022e3f BO |
63 | |
64 | return -ENODEV; | |
65 | } | |
66 | ||
56cfbf74 CC |
67 | /** |
68 | * cpuidle_enter_state - enter the state and update stats | |
69 | * @dev: cpuidle device for this cpu | |
70 | * @drv: cpuidle driver for this cpu | |
71 | * @next_state: index into drv->states of the state to enter | |
72 | */ | |
73 | int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, | |
554c06ba | 74 | int index) |
56cfbf74 CC |
75 | { |
76 | int entered_state; | |
77 | ||
554c06ba DL |
78 | struct cpuidle_state *target_state = &drv->states[index]; |
79 | ktime_t time_start, time_end; | |
80 | s64 diff; | |
81 | ||
82 | time_start = ktime_get(); | |
83 | ||
84 | entered_state = target_state->enter(dev, drv, index); | |
85 | ||
86 | time_end = ktime_get(); | |
87 | ||
88 | local_irq_enable(); | |
89 | ||
90 | diff = ktime_to_us(ktime_sub(time_end, time_start)); | |
91 | if (diff > INT_MAX) | |
92 | diff = INT_MAX; | |
93 | ||
94 | dev->last_residency = (int) diff; | |
56cfbf74 CC |
95 | |
96 | if (entered_state >= 0) { | |
97 | /* Update cpuidle counters */ | |
98 | /* This can be moved to within driver enter routine | |
99 | * but that results in multiple copies of same code. | |
100 | */ | |
a474a515 | 101 | dev->states_usage[entered_state].time += dev->last_residency; |
56cfbf74 CC |
102 | dev->states_usage[entered_state].usage++; |
103 | } else { | |
104 | dev->last_residency = 0; | |
105 | } | |
106 | ||
107 | return entered_state; | |
108 | } | |
109 | ||
4f86d3a8 LB |
110 | /** |
111 | * cpuidle_idle_call - the main idle loop | |
112 | * | |
113 | * NOTE: no locks or semaphores should be used here | |
a0bfa137 | 114 | * return non-zero on failure |
4f86d3a8 | 115 | */ |
a0bfa137 | 116 | int cpuidle_idle_call(void) |
4f86d3a8 | 117 | { |
4a6f4fe8 | 118 | struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); |
bf4d1b5d | 119 | struct cpuidle_driver *drv; |
e978aa7d | 120 | int next_state, entered_state; |
fb11c9c6 | 121 | bool broadcast; |
4f86d3a8 | 122 | |
9b29a86f | 123 | if (off || !initialized) |
a0bfa137 LB |
124 | return -ENODEV; |
125 | ||
4f86d3a8 | 126 | /* check if the device is ready */ |
a0bfa137 LB |
127 | if (!dev || !dev->enabled) |
128 | return -EBUSY; | |
4f86d3a8 | 129 | |
bf4d1b5d DL |
130 | drv = cpuidle_get_cpu_driver(dev); |
131 | ||
4f86d3a8 | 132 | /* ask the governor for the next state */ |
46bcfad7 | 133 | next_state = cpuidle_curr_governor->select(drv, dev); |
246eb7f0 | 134 | if (need_resched()) { |
d73d68dc YS |
135 | dev->last_residency = 0; |
136 | /* give the governor an opportunity to reflect on the outcome */ | |
137 | if (cpuidle_curr_governor->reflect) | |
138 | cpuidle_curr_governor->reflect(dev, next_state); | |
246eb7f0 | 139 | local_irq_enable(); |
a0bfa137 | 140 | return 0; |
246eb7f0 KH |
141 | } |
142 | ||
76027ea8 | 143 | trace_cpu_idle_rcuidle(next_state, dev->cpu); |
f77cfe4e | 144 | |
fb11c9c6 VK |
145 | broadcast = !!(drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP); |
146 | ||
147 | if (broadcast) | |
6d281e97 | 148 | clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu); |
b60e6a0e | 149 | |
4126c019 CC |
150 | if (cpuidle_state_is_coupled(dev, drv, next_state)) |
151 | entered_state = cpuidle_enter_state_coupled(dev, drv, | |
152 | next_state); | |
153 | else | |
154 | entered_state = cpuidle_enter_state(dev, drv, next_state); | |
f77cfe4e | 155 | |
fb11c9c6 | 156 | if (broadcast) |
6d281e97 | 157 | clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu); |
b60e6a0e | 158 | |
76027ea8 | 159 | trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); |
f77cfe4e | 160 | |
4f86d3a8 LB |
161 | /* give the governor an opportunity to reflect on the outcome */ |
162 | if (cpuidle_curr_governor->reflect) | |
e978aa7d | 163 | cpuidle_curr_governor->reflect(dev, entered_state); |
a0bfa137 LB |
164 | |
165 | return 0; | |
4f86d3a8 LB |
166 | } |
167 | ||
168 | /** | |
169 | * cpuidle_install_idle_handler - installs the cpuidle idle loop handler | |
170 | */ | |
171 | void cpuidle_install_idle_handler(void) | |
172 | { | |
a0bfa137 | 173 | if (enabled_devices) { |
4f86d3a8 LB |
174 | /* Make sure all changes finished before we switch to new idle */ |
175 | smp_wmb(); | |
a0bfa137 | 176 | initialized = 1; |
4f86d3a8 LB |
177 | } |
178 | } | |
179 | ||
180 | /** | |
181 | * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler | |
182 | */ | |
183 | void cpuidle_uninstall_idle_handler(void) | |
184 | { | |
a0bfa137 LB |
185 | if (enabled_devices) { |
186 | initialized = 0; | |
4a162513 | 187 | kick_all_cpus_sync(); |
4f86d3a8 LB |
188 | } |
189 | } | |
190 | ||
191 | /** | |
192 | * cpuidle_pause_and_lock - temporarily disables CPUIDLE | |
193 | */ | |
194 | void cpuidle_pause_and_lock(void) | |
195 | { | |
196 | mutex_lock(&cpuidle_lock); | |
197 | cpuidle_uninstall_idle_handler(); | |
198 | } | |
199 | ||
200 | EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock); | |
201 | ||
202 | /** | |
203 | * cpuidle_resume_and_unlock - resumes CPUIDLE operation | |
204 | */ | |
205 | void cpuidle_resume_and_unlock(void) | |
206 | { | |
207 | cpuidle_install_idle_handler(); | |
208 | mutex_unlock(&cpuidle_lock); | |
209 | } | |
210 | ||
211 | EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); | |
212 | ||
8651f97b PM |
213 | /* Currently used in suspend/resume path to suspend cpuidle */ |
214 | void cpuidle_pause(void) | |
215 | { | |
216 | mutex_lock(&cpuidle_lock); | |
217 | cpuidle_uninstall_idle_handler(); | |
218 | mutex_unlock(&cpuidle_lock); | |
219 | } | |
220 | ||
221 | /* Currently used in suspend/resume path to resume cpuidle */ | |
222 | void cpuidle_resume(void) | |
223 | { | |
224 | mutex_lock(&cpuidle_lock); | |
225 | cpuidle_install_idle_handler(); | |
226 | mutex_unlock(&cpuidle_lock); | |
227 | } | |
228 | ||
4f86d3a8 LB |
229 | /** |
230 | * cpuidle_enable_device - enables idle PM for a CPU | |
231 | * @dev: the CPU | |
232 | * | |
233 | * This function must be called between cpuidle_pause_and_lock and | |
234 | * cpuidle_resume_and_unlock when used externally. | |
235 | */ | |
236 | int cpuidle_enable_device(struct cpuidle_device *dev) | |
237 | { | |
5df0aa73 | 238 | int ret; |
bf4d1b5d | 239 | struct cpuidle_driver *drv; |
4f86d3a8 | 240 | |
1b0a0e9a SB |
241 | if (!dev) |
242 | return -EINVAL; | |
243 | ||
4f86d3a8 LB |
244 | if (dev->enabled) |
245 | return 0; | |
bf4d1b5d DL |
246 | |
247 | drv = cpuidle_get_cpu_driver(dev); | |
248 | ||
e1689795 | 249 | if (!drv || !cpuidle_curr_governor) |
4f86d3a8 | 250 | return -EIO; |
bf4d1b5d | 251 | |
10b9d3f8 DL |
252 | if (!dev->registered) |
253 | return -EINVAL; | |
254 | ||
4f86d3a8 | 255 | if (!dev->state_count) |
fc850f39 | 256 | dev->state_count = drv->state_count; |
4f86d3a8 | 257 | |
bf4d1b5d DL |
258 | ret = cpuidle_add_device_sysfs(dev); |
259 | if (ret) | |
4f86d3a8 LB |
260 | return ret; |
261 | ||
262 | if (cpuidle_curr_governor->enable && | |
e1689795 | 263 | (ret = cpuidle_curr_governor->enable(drv, dev))) |
4f86d3a8 LB |
264 | goto fail_sysfs; |
265 | ||
4f86d3a8 LB |
266 | smp_wmb(); |
267 | ||
268 | dev->enabled = 1; | |
269 | ||
270 | enabled_devices++; | |
271 | return 0; | |
272 | ||
273 | fail_sysfs: | |
bf4d1b5d | 274 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
275 | |
276 | return ret; | |
277 | } | |
278 | ||
279 | EXPORT_SYMBOL_GPL(cpuidle_enable_device); | |
280 | ||
281 | /** | |
282 | * cpuidle_disable_device - disables idle PM for a CPU | |
283 | * @dev: the CPU | |
284 | * | |
285 | * This function must be called between cpuidle_pause_and_lock and | |
286 | * cpuidle_resume_and_unlock when used externally. | |
287 | */ | |
288 | void cpuidle_disable_device(struct cpuidle_device *dev) | |
289 | { | |
bf4d1b5d DL |
290 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
291 | ||
cf31cd1a | 292 | if (!dev || !dev->enabled) |
4f86d3a8 | 293 | return; |
bf4d1b5d DL |
294 | |
295 | if (!drv || !cpuidle_curr_governor) | |
4f86d3a8 LB |
296 | return; |
297 | ||
298 | dev->enabled = 0; | |
299 | ||
300 | if (cpuidle_curr_governor->disable) | |
bf4d1b5d | 301 | cpuidle_curr_governor->disable(drv, dev); |
4f86d3a8 | 302 | |
bf4d1b5d | 303 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
304 | enabled_devices--; |
305 | } | |
306 | ||
307 | EXPORT_SYMBOL_GPL(cpuidle_disable_device); | |
308 | ||
f6bb51a5 DL |
309 | static void __cpuidle_unregister_device(struct cpuidle_device *dev) |
310 | { | |
311 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); | |
312 | ||
313 | list_del(&dev->device_list); | |
314 | per_cpu(cpuidle_devices, dev->cpu) = NULL; | |
315 | module_put(drv->owner); | |
316 | } | |
317 | ||
267d4bf8 | 318 | static void __cpuidle_device_init(struct cpuidle_device *dev) |
5df0aa73 DL |
319 | { |
320 | memset(dev->states_usage, 0, sizeof(dev->states_usage)); | |
321 | dev->last_residency = 0; | |
5df0aa73 DL |
322 | } |
323 | ||
4f86d3a8 | 324 | /** |
dcb84f33 VP |
325 | * __cpuidle_register_device - internal register function called before register |
326 | * and enable routines | |
4f86d3a8 | 327 | * @dev: the cpu |
dcb84f33 VP |
328 | * |
329 | * cpuidle_lock mutex must be held before this is called | |
4f86d3a8 | 330 | */ |
dcb84f33 | 331 | static int __cpuidle_register_device(struct cpuidle_device *dev) |
4f86d3a8 LB |
332 | { |
333 | int ret; | |
bf4d1b5d | 334 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
4f86d3a8 | 335 | |
bf4d1b5d | 336 | if (!try_module_get(drv->owner)) |
4f86d3a8 LB |
337 | return -EINVAL; |
338 | ||
4f86d3a8 LB |
339 | per_cpu(cpuidle_devices, dev->cpu) = dev; |
340 | list_add(&dev->device_list, &cpuidle_detected_devices); | |
4f86d3a8 | 341 | |
4126c019 | 342 | ret = cpuidle_coupled_register_device(dev); |
47182668 | 343 | if (ret) |
f6bb51a5 | 344 | __cpuidle_unregister_device(dev); |
47182668 VK |
345 | else |
346 | dev->registered = 1; | |
4f86d3a8 | 347 | |
47182668 | 348 | return ret; |
dcb84f33 VP |
349 | } |
350 | ||
351 | /** | |
352 | * cpuidle_register_device - registers a CPU's idle PM feature | |
353 | * @dev: the cpu | |
354 | */ | |
355 | int cpuidle_register_device(struct cpuidle_device *dev) | |
356 | { | |
c878a52d | 357 | int ret = -EBUSY; |
dcb84f33 | 358 | |
1b0a0e9a SB |
359 | if (!dev) |
360 | return -EINVAL; | |
361 | ||
dcb84f33 VP |
362 | mutex_lock(&cpuidle_lock); |
363 | ||
c878a52d DL |
364 | if (dev->registered) |
365 | goto out_unlock; | |
366 | ||
267d4bf8 | 367 | __cpuidle_device_init(dev); |
5df0aa73 | 368 | |
f6bb51a5 DL |
369 | ret = __cpuidle_register_device(dev); |
370 | if (ret) | |
371 | goto out_unlock; | |
372 | ||
373 | ret = cpuidle_add_sysfs(dev); | |
374 | if (ret) | |
375 | goto out_unregister; | |
dcb84f33 | 376 | |
10b9d3f8 | 377 | ret = cpuidle_enable_device(dev); |
f6bb51a5 DL |
378 | if (ret) |
379 | goto out_sysfs; | |
10b9d3f8 | 380 | |
4f86d3a8 LB |
381 | cpuidle_install_idle_handler(); |
382 | ||
f6bb51a5 | 383 | out_unlock: |
4f86d3a8 LB |
384 | mutex_unlock(&cpuidle_lock); |
385 | ||
f6bb51a5 DL |
386 | return ret; |
387 | ||
388 | out_sysfs: | |
389 | cpuidle_remove_sysfs(dev); | |
390 | out_unregister: | |
391 | __cpuidle_unregister_device(dev); | |
392 | goto out_unlock; | |
4f86d3a8 LB |
393 | } |
394 | ||
395 | EXPORT_SYMBOL_GPL(cpuidle_register_device); | |
396 | ||
397 | /** | |
398 | * cpuidle_unregister_device - unregisters a CPU's idle PM feature | |
399 | * @dev: the cpu | |
400 | */ | |
401 | void cpuidle_unregister_device(struct cpuidle_device *dev) | |
402 | { | |
dcb84f33 VP |
403 | if (dev->registered == 0) |
404 | return; | |
405 | ||
4f86d3a8 LB |
406 | cpuidle_pause_and_lock(); |
407 | ||
408 | cpuidle_disable_device(dev); | |
409 | ||
1aef40e2 | 410 | cpuidle_remove_sysfs(dev); |
f6bb51a5 DL |
411 | |
412 | __cpuidle_unregister_device(dev); | |
4f86d3a8 | 413 | |
4126c019 CC |
414 | cpuidle_coupled_unregister_device(dev); |
415 | ||
4f86d3a8 | 416 | cpuidle_resume_and_unlock(); |
4f86d3a8 LB |
417 | } |
418 | ||
419 | EXPORT_SYMBOL_GPL(cpuidle_unregister_device); | |
420 | ||
1c192d04 | 421 | /** |
4c637b21 DL |
422 | * cpuidle_unregister: unregister a driver and the devices. This function |
423 | * can be used only if the driver has been previously registered through | |
424 | * the cpuidle_register function. | |
425 | * | |
426 | * @drv: a valid pointer to a struct cpuidle_driver | |
427 | */ | |
428 | void cpuidle_unregister(struct cpuidle_driver *drv) | |
429 | { | |
430 | int cpu; | |
431 | struct cpuidle_device *device; | |
432 | ||
82467a5a | 433 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
434 | device = &per_cpu(cpuidle_dev, cpu); |
435 | cpuidle_unregister_device(device); | |
436 | } | |
437 | ||
438 | cpuidle_unregister_driver(drv); | |
439 | } | |
440 | EXPORT_SYMBOL_GPL(cpuidle_unregister); | |
441 | ||
442 | /** | |
443 | * cpuidle_register: registers the driver and the cpu devices with the | |
444 | * coupled_cpus passed as parameter. This function is used for all common | |
445 | * initialization pattern there are in the arch specific drivers. The | |
446 | * devices is globally defined in this file. | |
447 | * | |
448 | * @drv : a valid pointer to a struct cpuidle_driver | |
449 | * @coupled_cpus: a cpumask for the coupled states | |
450 | * | |
451 | * Returns 0 on success, < 0 otherwise | |
452 | */ | |
453 | int cpuidle_register(struct cpuidle_driver *drv, | |
454 | const struct cpumask *const coupled_cpus) | |
455 | { | |
456 | int ret, cpu; | |
457 | struct cpuidle_device *device; | |
458 | ||
459 | ret = cpuidle_register_driver(drv); | |
460 | if (ret) { | |
461 | pr_err("failed to register cpuidle driver\n"); | |
462 | return ret; | |
463 | } | |
464 | ||
82467a5a | 465 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
466 | device = &per_cpu(cpuidle_dev, cpu); |
467 | device->cpu = cpu; | |
468 | ||
469 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED | |
470 | /* | |
caf4a36e | 471 | * On multiplatform for ARM, the coupled idle states could be |
4c637b21 DL |
472 | * enabled in the kernel even if the cpuidle driver does not |
473 | * use it. Note, coupled_cpus is a struct copy. | |
474 | */ | |
475 | if (coupled_cpus) | |
476 | device->coupled_cpus = *coupled_cpus; | |
477 | #endif | |
478 | ret = cpuidle_register_device(device); | |
479 | if (!ret) | |
480 | continue; | |
481 | ||
482 | pr_err("Failed to register cpuidle device for cpu%d\n", cpu); | |
483 | ||
484 | cpuidle_unregister(drv); | |
485 | break; | |
486 | } | |
487 | ||
488 | return ret; | |
489 | } | |
490 | EXPORT_SYMBOL_GPL(cpuidle_register); | |
491 | ||
4f86d3a8 LB |
492 | #ifdef CONFIG_SMP |
493 | ||
494 | static void smp_callback(void *v) | |
495 | { | |
496 | /* we already woke the CPU up, nothing more to do */ | |
497 | } | |
498 | ||
499 | /* | |
500 | * This function gets called when a part of the kernel has a new latency | |
501 | * requirement. This means we need to get all processors out of their C-state, | |
502 | * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that | |
503 | * wakes them all right up. | |
504 | */ | |
505 | static int cpuidle_latency_notify(struct notifier_block *b, | |
506 | unsigned long l, void *v) | |
507 | { | |
8691e5a8 | 508 | smp_call_function(smp_callback, NULL, 1); |
4f86d3a8 LB |
509 | return NOTIFY_OK; |
510 | } | |
511 | ||
512 | static struct notifier_block cpuidle_latency_notifier = { | |
513 | .notifier_call = cpuidle_latency_notify, | |
514 | }; | |
515 | ||
d82b3518 MG |
516 | static inline void latency_notifier_init(struct notifier_block *n) |
517 | { | |
518 | pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n); | |
519 | } | |
4f86d3a8 LB |
520 | |
521 | #else /* CONFIG_SMP */ | |
522 | ||
523 | #define latency_notifier_init(x) do { } while (0) | |
524 | ||
525 | #endif /* CONFIG_SMP */ | |
526 | ||
527 | /** | |
528 | * cpuidle_init - core initializer | |
529 | */ | |
530 | static int __init cpuidle_init(void) | |
531 | { | |
532 | int ret; | |
533 | ||
62027aea LB |
534 | if (cpuidle_disabled()) |
535 | return -ENODEV; | |
536 | ||
8a25a2fd | 537 | ret = cpuidle_add_interface(cpu_subsys.dev_root); |
4f86d3a8 LB |
538 | if (ret) |
539 | return ret; | |
540 | ||
541 | latency_notifier_init(&cpuidle_latency_notifier); | |
542 | ||
543 | return 0; | |
544 | } | |
545 | ||
62027aea | 546 | module_param(off, int, 0444); |
4f86d3a8 | 547 | core_initcall(cpuidle_init); |