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 | ||
907e30f1 DL |
67 | /** |
68 | * cpuidle_enabled - check if the cpuidle framework is ready | |
69 | * @dev: cpuidle device for this cpu | |
70 | * @drv: cpuidle driver for this cpu | |
71 | * | |
72 | * Return 0 on success, otherwise: | |
73 | * -NODEV : the cpuidle framework is not available | |
74 | * -EBUSY : the cpuidle framework is not initialized | |
75 | */ | |
76 | int cpuidle_enabled(struct cpuidle_driver *drv, struct cpuidle_device *dev) | |
77 | { | |
78 | if (off || !initialized) | |
79 | return -ENODEV; | |
80 | ||
81 | if (!drv || !dev || !dev->enabled) | |
82 | return -EBUSY; | |
83 | ||
84 | return 0; | |
85 | } | |
86 | ||
56cfbf74 CC |
87 | /** |
88 | * cpuidle_enter_state - enter the state and update stats | |
89 | * @dev: cpuidle device for this cpu | |
90 | * @drv: cpuidle driver for this cpu | |
91 | * @next_state: index into drv->states of the state to enter | |
92 | */ | |
93 | int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, | |
554c06ba | 94 | int index) |
56cfbf74 CC |
95 | { |
96 | int entered_state; | |
97 | ||
554c06ba DL |
98 | struct cpuidle_state *target_state = &drv->states[index]; |
99 | ktime_t time_start, time_end; | |
100 | s64 diff; | |
101 | ||
102 | time_start = ktime_get(); | |
103 | ||
104 | entered_state = target_state->enter(dev, drv, index); | |
105 | ||
106 | time_end = ktime_get(); | |
107 | ||
0b89e9aa PB |
108 | if (!cpuidle_state_is_coupled(dev, drv, entered_state)) |
109 | local_irq_enable(); | |
554c06ba DL |
110 | |
111 | diff = ktime_to_us(ktime_sub(time_end, time_start)); | |
112 | if (diff > INT_MAX) | |
113 | diff = INT_MAX; | |
114 | ||
115 | dev->last_residency = (int) diff; | |
56cfbf74 CC |
116 | |
117 | if (entered_state >= 0) { | |
118 | /* Update cpuidle counters */ | |
119 | /* This can be moved to within driver enter routine | |
120 | * but that results in multiple copies of same code. | |
121 | */ | |
a474a515 | 122 | dev->states_usage[entered_state].time += dev->last_residency; |
56cfbf74 CC |
123 | dev->states_usage[entered_state].usage++; |
124 | } else { | |
125 | dev->last_residency = 0; | |
126 | } | |
127 | ||
128 | return entered_state; | |
129 | } | |
130 | ||
4f86d3a8 | 131 | /** |
907e30f1 DL |
132 | * cpuidle_select - ask the cpuidle framework to choose an idle state |
133 | * | |
134 | * @drv: the cpuidle driver | |
135 | * @dev: the cpuidle device | |
4f86d3a8 | 136 | * |
907e30f1 | 137 | * Returns the index of the idle state. |
4f86d3a8 | 138 | */ |
907e30f1 | 139 | int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
4f86d3a8 | 140 | { |
907e30f1 DL |
141 | return cpuidle_curr_governor->select(drv, dev); |
142 | } | |
ba8f20c2 | 143 | |
907e30f1 DL |
144 | /** |
145 | * cpuidle_enter - enter into the specified idle state | |
146 | * | |
147 | * @drv: the cpuidle driver tied with the cpu | |
148 | * @dev: the cpuidle device | |
149 | * @index: the index in the idle state table | |
150 | * | |
151 | * Returns the index in the idle state, < 0 in case of error. | |
152 | * The error code depends on the backend driver | |
153 | */ | |
154 | int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, | |
155 | int index) | |
156 | { | |
157 | if (cpuidle_state_is_coupled(dev, drv, index)) | |
158 | return cpuidle_enter_state_coupled(dev, drv, index); | |
159 | return cpuidle_enter_state(dev, drv, index); | |
160 | } | |
b60e6a0e | 161 | |
907e30f1 DL |
162 | /** |
163 | * cpuidle_reflect - tell the underlying governor what was the state | |
164 | * we were in | |
165 | * | |
166 | * @dev : the cpuidle device | |
167 | * @index: the index in the idle state table | |
168 | * | |
169 | */ | |
170 | void cpuidle_reflect(struct cpuidle_device *dev, int index) | |
171 | { | |
4f86d3a8 | 172 | if (cpuidle_curr_governor->reflect) |
907e30f1 | 173 | cpuidle_curr_governor->reflect(dev, index); |
4f86d3a8 LB |
174 | } |
175 | ||
176 | /** | |
177 | * cpuidle_install_idle_handler - installs the cpuidle idle loop handler | |
178 | */ | |
179 | void cpuidle_install_idle_handler(void) | |
180 | { | |
a0bfa137 | 181 | if (enabled_devices) { |
4f86d3a8 LB |
182 | /* Make sure all changes finished before we switch to new idle */ |
183 | smp_wmb(); | |
a0bfa137 | 184 | initialized = 1; |
4f86d3a8 LB |
185 | } |
186 | } | |
187 | ||
188 | /** | |
189 | * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler | |
190 | */ | |
191 | void cpuidle_uninstall_idle_handler(void) | |
192 | { | |
a0bfa137 LB |
193 | if (enabled_devices) { |
194 | initialized = 0; | |
4a162513 | 195 | kick_all_cpus_sync(); |
4f86d3a8 LB |
196 | } |
197 | } | |
198 | ||
199 | /** | |
200 | * cpuidle_pause_and_lock - temporarily disables CPUIDLE | |
201 | */ | |
202 | void cpuidle_pause_and_lock(void) | |
203 | { | |
204 | mutex_lock(&cpuidle_lock); | |
205 | cpuidle_uninstall_idle_handler(); | |
206 | } | |
207 | ||
208 | EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock); | |
209 | ||
210 | /** | |
211 | * cpuidle_resume_and_unlock - resumes CPUIDLE operation | |
212 | */ | |
213 | void cpuidle_resume_and_unlock(void) | |
214 | { | |
215 | cpuidle_install_idle_handler(); | |
216 | mutex_unlock(&cpuidle_lock); | |
217 | } | |
218 | ||
219 | EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); | |
220 | ||
8651f97b PM |
221 | /* Currently used in suspend/resume path to suspend cpuidle */ |
222 | void cpuidle_pause(void) | |
223 | { | |
224 | mutex_lock(&cpuidle_lock); | |
225 | cpuidle_uninstall_idle_handler(); | |
226 | mutex_unlock(&cpuidle_lock); | |
227 | } | |
228 | ||
229 | /* Currently used in suspend/resume path to resume cpuidle */ | |
230 | void cpuidle_resume(void) | |
231 | { | |
232 | mutex_lock(&cpuidle_lock); | |
233 | cpuidle_install_idle_handler(); | |
234 | mutex_unlock(&cpuidle_lock); | |
235 | } | |
236 | ||
4f86d3a8 LB |
237 | /** |
238 | * cpuidle_enable_device - enables idle PM for a CPU | |
239 | * @dev: the CPU | |
240 | * | |
241 | * This function must be called between cpuidle_pause_and_lock and | |
242 | * cpuidle_resume_and_unlock when used externally. | |
243 | */ | |
244 | int cpuidle_enable_device(struct cpuidle_device *dev) | |
245 | { | |
5df0aa73 | 246 | int ret; |
bf4d1b5d | 247 | struct cpuidle_driver *drv; |
4f86d3a8 | 248 | |
1b0a0e9a SB |
249 | if (!dev) |
250 | return -EINVAL; | |
251 | ||
4f86d3a8 LB |
252 | if (dev->enabled) |
253 | return 0; | |
bf4d1b5d DL |
254 | |
255 | drv = cpuidle_get_cpu_driver(dev); | |
256 | ||
e1689795 | 257 | if (!drv || !cpuidle_curr_governor) |
4f86d3a8 | 258 | return -EIO; |
bf4d1b5d | 259 | |
10b9d3f8 DL |
260 | if (!dev->registered) |
261 | return -EINVAL; | |
262 | ||
4f86d3a8 | 263 | if (!dev->state_count) |
fc850f39 | 264 | dev->state_count = drv->state_count; |
4f86d3a8 | 265 | |
bf4d1b5d DL |
266 | ret = cpuidle_add_device_sysfs(dev); |
267 | if (ret) | |
4f86d3a8 LB |
268 | return ret; |
269 | ||
270 | if (cpuidle_curr_governor->enable && | |
e1689795 | 271 | (ret = cpuidle_curr_governor->enable(drv, dev))) |
4f86d3a8 LB |
272 | goto fail_sysfs; |
273 | ||
4f86d3a8 LB |
274 | smp_wmb(); |
275 | ||
276 | dev->enabled = 1; | |
277 | ||
278 | enabled_devices++; | |
279 | return 0; | |
280 | ||
281 | fail_sysfs: | |
bf4d1b5d | 282 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
283 | |
284 | return ret; | |
285 | } | |
286 | ||
287 | EXPORT_SYMBOL_GPL(cpuidle_enable_device); | |
288 | ||
289 | /** | |
290 | * cpuidle_disable_device - disables idle PM for a CPU | |
291 | * @dev: the CPU | |
292 | * | |
293 | * This function must be called between cpuidle_pause_and_lock and | |
294 | * cpuidle_resume_and_unlock when used externally. | |
295 | */ | |
296 | void cpuidle_disable_device(struct cpuidle_device *dev) | |
297 | { | |
bf4d1b5d DL |
298 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
299 | ||
cf31cd1a | 300 | if (!dev || !dev->enabled) |
4f86d3a8 | 301 | return; |
bf4d1b5d DL |
302 | |
303 | if (!drv || !cpuidle_curr_governor) | |
4f86d3a8 LB |
304 | return; |
305 | ||
306 | dev->enabled = 0; | |
307 | ||
308 | if (cpuidle_curr_governor->disable) | |
bf4d1b5d | 309 | cpuidle_curr_governor->disable(drv, dev); |
4f86d3a8 | 310 | |
bf4d1b5d | 311 | cpuidle_remove_device_sysfs(dev); |
4f86d3a8 LB |
312 | enabled_devices--; |
313 | } | |
314 | ||
315 | EXPORT_SYMBOL_GPL(cpuidle_disable_device); | |
316 | ||
f6bb51a5 DL |
317 | static void __cpuidle_unregister_device(struct cpuidle_device *dev) |
318 | { | |
319 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); | |
320 | ||
321 | list_del(&dev->device_list); | |
322 | per_cpu(cpuidle_devices, dev->cpu) = NULL; | |
323 | module_put(drv->owner); | |
324 | } | |
325 | ||
267d4bf8 | 326 | static void __cpuidle_device_init(struct cpuidle_device *dev) |
5df0aa73 DL |
327 | { |
328 | memset(dev->states_usage, 0, sizeof(dev->states_usage)); | |
329 | dev->last_residency = 0; | |
5df0aa73 DL |
330 | } |
331 | ||
4f86d3a8 | 332 | /** |
dcb84f33 VP |
333 | * __cpuidle_register_device - internal register function called before register |
334 | * and enable routines | |
4f86d3a8 | 335 | * @dev: the cpu |
dcb84f33 VP |
336 | * |
337 | * cpuidle_lock mutex must be held before this is called | |
4f86d3a8 | 338 | */ |
dcb84f33 | 339 | static int __cpuidle_register_device(struct cpuidle_device *dev) |
4f86d3a8 LB |
340 | { |
341 | int ret; | |
bf4d1b5d | 342 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
4f86d3a8 | 343 | |
bf4d1b5d | 344 | if (!try_module_get(drv->owner)) |
4f86d3a8 LB |
345 | return -EINVAL; |
346 | ||
4f86d3a8 LB |
347 | per_cpu(cpuidle_devices, dev->cpu) = dev; |
348 | list_add(&dev->device_list, &cpuidle_detected_devices); | |
4f86d3a8 | 349 | |
4126c019 | 350 | ret = cpuidle_coupled_register_device(dev); |
47182668 | 351 | if (ret) |
f6bb51a5 | 352 | __cpuidle_unregister_device(dev); |
47182668 VK |
353 | else |
354 | dev->registered = 1; | |
4f86d3a8 | 355 | |
47182668 | 356 | return ret; |
dcb84f33 VP |
357 | } |
358 | ||
359 | /** | |
360 | * cpuidle_register_device - registers a CPU's idle PM feature | |
361 | * @dev: the cpu | |
362 | */ | |
363 | int cpuidle_register_device(struct cpuidle_device *dev) | |
364 | { | |
c878a52d | 365 | int ret = -EBUSY; |
dcb84f33 | 366 | |
1b0a0e9a SB |
367 | if (!dev) |
368 | return -EINVAL; | |
369 | ||
dcb84f33 VP |
370 | mutex_lock(&cpuidle_lock); |
371 | ||
c878a52d DL |
372 | if (dev->registered) |
373 | goto out_unlock; | |
374 | ||
267d4bf8 | 375 | __cpuidle_device_init(dev); |
5df0aa73 | 376 | |
f6bb51a5 DL |
377 | ret = __cpuidle_register_device(dev); |
378 | if (ret) | |
379 | goto out_unlock; | |
380 | ||
381 | ret = cpuidle_add_sysfs(dev); | |
382 | if (ret) | |
383 | goto out_unregister; | |
dcb84f33 | 384 | |
10b9d3f8 | 385 | ret = cpuidle_enable_device(dev); |
f6bb51a5 DL |
386 | if (ret) |
387 | goto out_sysfs; | |
10b9d3f8 | 388 | |
4f86d3a8 LB |
389 | cpuidle_install_idle_handler(); |
390 | ||
f6bb51a5 | 391 | out_unlock: |
4f86d3a8 LB |
392 | mutex_unlock(&cpuidle_lock); |
393 | ||
f6bb51a5 DL |
394 | return ret; |
395 | ||
396 | out_sysfs: | |
397 | cpuidle_remove_sysfs(dev); | |
398 | out_unregister: | |
399 | __cpuidle_unregister_device(dev); | |
400 | goto out_unlock; | |
4f86d3a8 LB |
401 | } |
402 | ||
403 | EXPORT_SYMBOL_GPL(cpuidle_register_device); | |
404 | ||
405 | /** | |
406 | * cpuidle_unregister_device - unregisters a CPU's idle PM feature | |
407 | * @dev: the cpu | |
408 | */ | |
409 | void cpuidle_unregister_device(struct cpuidle_device *dev) | |
410 | { | |
813e8e3d | 411 | if (!dev || dev->registered == 0) |
dcb84f33 VP |
412 | return; |
413 | ||
4f86d3a8 LB |
414 | cpuidle_pause_and_lock(); |
415 | ||
416 | cpuidle_disable_device(dev); | |
417 | ||
1aef40e2 | 418 | cpuidle_remove_sysfs(dev); |
f6bb51a5 DL |
419 | |
420 | __cpuidle_unregister_device(dev); | |
4f86d3a8 | 421 | |
4126c019 CC |
422 | cpuidle_coupled_unregister_device(dev); |
423 | ||
4f86d3a8 | 424 | cpuidle_resume_and_unlock(); |
4f86d3a8 LB |
425 | } |
426 | ||
427 | EXPORT_SYMBOL_GPL(cpuidle_unregister_device); | |
428 | ||
1c192d04 | 429 | /** |
4c637b21 DL |
430 | * cpuidle_unregister: unregister a driver and the devices. This function |
431 | * can be used only if the driver has been previously registered through | |
432 | * the cpuidle_register function. | |
433 | * | |
434 | * @drv: a valid pointer to a struct cpuidle_driver | |
435 | */ | |
436 | void cpuidle_unregister(struct cpuidle_driver *drv) | |
437 | { | |
438 | int cpu; | |
439 | struct cpuidle_device *device; | |
440 | ||
82467a5a | 441 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
442 | device = &per_cpu(cpuidle_dev, cpu); |
443 | cpuidle_unregister_device(device); | |
444 | } | |
445 | ||
446 | cpuidle_unregister_driver(drv); | |
447 | } | |
448 | EXPORT_SYMBOL_GPL(cpuidle_unregister); | |
449 | ||
450 | /** | |
451 | * cpuidle_register: registers the driver and the cpu devices with the | |
452 | * coupled_cpus passed as parameter. This function is used for all common | |
453 | * initialization pattern there are in the arch specific drivers. The | |
454 | * devices is globally defined in this file. | |
455 | * | |
456 | * @drv : a valid pointer to a struct cpuidle_driver | |
457 | * @coupled_cpus: a cpumask for the coupled states | |
458 | * | |
459 | * Returns 0 on success, < 0 otherwise | |
460 | */ | |
461 | int cpuidle_register(struct cpuidle_driver *drv, | |
462 | const struct cpumask *const coupled_cpus) | |
463 | { | |
464 | int ret, cpu; | |
465 | struct cpuidle_device *device; | |
466 | ||
467 | ret = cpuidle_register_driver(drv); | |
468 | if (ret) { | |
469 | pr_err("failed to register cpuidle driver\n"); | |
470 | return ret; | |
471 | } | |
472 | ||
82467a5a | 473 | for_each_cpu(cpu, drv->cpumask) { |
4c637b21 DL |
474 | device = &per_cpu(cpuidle_dev, cpu); |
475 | device->cpu = cpu; | |
476 | ||
477 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED | |
478 | /* | |
caf4a36e | 479 | * On multiplatform for ARM, the coupled idle states could be |
4c637b21 DL |
480 | * enabled in the kernel even if the cpuidle driver does not |
481 | * use it. Note, coupled_cpus is a struct copy. | |
482 | */ | |
483 | if (coupled_cpus) | |
484 | device->coupled_cpus = *coupled_cpus; | |
485 | #endif | |
486 | ret = cpuidle_register_device(device); | |
487 | if (!ret) | |
488 | continue; | |
489 | ||
490 | pr_err("Failed to register cpuidle device for cpu%d\n", cpu); | |
491 | ||
492 | cpuidle_unregister(drv); | |
493 | break; | |
494 | } | |
495 | ||
496 | return ret; | |
497 | } | |
498 | EXPORT_SYMBOL_GPL(cpuidle_register); | |
499 | ||
4f86d3a8 LB |
500 | #ifdef CONFIG_SMP |
501 | ||
502 | static void smp_callback(void *v) | |
503 | { | |
504 | /* we already woke the CPU up, nothing more to do */ | |
505 | } | |
506 | ||
507 | /* | |
508 | * This function gets called when a part of the kernel has a new latency | |
509 | * requirement. This means we need to get all processors out of their C-state, | |
510 | * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that | |
511 | * wakes them all right up. | |
512 | */ | |
513 | static int cpuidle_latency_notify(struct notifier_block *b, | |
514 | unsigned long l, void *v) | |
515 | { | |
8691e5a8 | 516 | smp_call_function(smp_callback, NULL, 1); |
4f86d3a8 LB |
517 | return NOTIFY_OK; |
518 | } | |
519 | ||
520 | static struct notifier_block cpuidle_latency_notifier = { | |
521 | .notifier_call = cpuidle_latency_notify, | |
522 | }; | |
523 | ||
d82b3518 MG |
524 | static inline void latency_notifier_init(struct notifier_block *n) |
525 | { | |
526 | pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n); | |
527 | } | |
4f86d3a8 LB |
528 | |
529 | #else /* CONFIG_SMP */ | |
530 | ||
531 | #define latency_notifier_init(x) do { } while (0) | |
532 | ||
533 | #endif /* CONFIG_SMP */ | |
534 | ||
535 | /** | |
536 | * cpuidle_init - core initializer | |
537 | */ | |
538 | static int __init cpuidle_init(void) | |
539 | { | |
540 | int ret; | |
541 | ||
62027aea LB |
542 | if (cpuidle_disabled()) |
543 | return -ENODEV; | |
544 | ||
8a25a2fd | 545 | ret = cpuidle_add_interface(cpu_subsys.dev_root); |
4f86d3a8 LB |
546 | if (ret) |
547 | return ret; | |
548 | ||
549 | latency_notifier_init(&cpuidle_latency_notifier); | |
550 | ||
551 | return 0; | |
552 | } | |
553 | ||
62027aea | 554 | module_param(off, int, 0444); |
4f86d3a8 | 555 | core_initcall(cpuidle_init); |