Commit | Line | Data |
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d316c57f TG |
1 | /* |
2 | * linux/kernel/time/clockevents.c | |
3 | * | |
4 | * This file contains functions which manage clock event devices. | |
5 | * | |
6 | * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de> | |
7 | * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar | |
8 | * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner | |
9 | * | |
10 | * This code is licenced under the GPL version 2. For details see | |
11 | * kernel-base/COPYING. | |
12 | */ | |
13 | ||
14 | #include <linux/clockchips.h> | |
15 | #include <linux/hrtimer.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/module.h> | |
d316c57f | 18 | #include <linux/smp.h> |
501f8670 | 19 | #include <linux/device.h> |
d316c57f | 20 | |
8e1a928a HS |
21 | #include "tick-internal.h" |
22 | ||
d316c57f TG |
23 | /* The registered clock event devices */ |
24 | static LIST_HEAD(clockevent_devices); | |
25 | static LIST_HEAD(clockevents_released); | |
d316c57f | 26 | /* Protection for the above */ |
b5f91da0 | 27 | static DEFINE_RAW_SPINLOCK(clockevents_lock); |
03e13cf5 TG |
28 | /* Protection for unbind operations */ |
29 | static DEFINE_MUTEX(clockevents_mutex); | |
30 | ||
31 | struct ce_unbind { | |
32 | struct clock_event_device *ce; | |
33 | int res; | |
34 | }; | |
d316c57f | 35 | |
97b94106 TG |
36 | static u64 cev_delta2ns(unsigned long latch, struct clock_event_device *evt, |
37 | bool ismax) | |
d316c57f | 38 | { |
97813f2f | 39 | u64 clc = (u64) latch << evt->shift; |
97b94106 | 40 | u64 rnd; |
d316c57f | 41 | |
45fe4fe1 IM |
42 | if (unlikely(!evt->mult)) { |
43 | evt->mult = 1; | |
44 | WARN_ON(1); | |
45 | } | |
97b94106 TG |
46 | rnd = (u64) evt->mult - 1; |
47 | ||
48 | /* | |
49 | * Upper bound sanity check. If the backwards conversion is | |
50 | * not equal latch, we know that the above shift overflowed. | |
51 | */ | |
52 | if ((clc >> evt->shift) != (u64)latch) | |
53 | clc = ~0ULL; | |
54 | ||
55 | /* | |
56 | * Scaled math oddities: | |
57 | * | |
58 | * For mult <= (1 << shift) we can safely add mult - 1 to | |
59 | * prevent integer rounding loss. So the backwards conversion | |
60 | * from nsec to device ticks will be correct. | |
61 | * | |
62 | * For mult > (1 << shift), i.e. device frequency is > 1GHz we | |
63 | * need to be careful. Adding mult - 1 will result in a value | |
64 | * which when converted back to device ticks can be larger | |
65 | * than latch by up to (mult - 1) >> shift. For the min_delta | |
66 | * calculation we still want to apply this in order to stay | |
67 | * above the minimum device ticks limit. For the upper limit | |
68 | * we would end up with a latch value larger than the upper | |
69 | * limit of the device, so we omit the add to stay below the | |
70 | * device upper boundary. | |
71 | * | |
72 | * Also omit the add if it would overflow the u64 boundary. | |
73 | */ | |
74 | if ((~0ULL - clc > rnd) && | |
75 | (!ismax || evt->mult <= (1U << evt->shift))) | |
76 | clc += rnd; | |
45fe4fe1 | 77 | |
d316c57f | 78 | do_div(clc, evt->mult); |
d316c57f | 79 | |
97b94106 TG |
80 | /* Deltas less than 1usec are pointless noise */ |
81 | return clc > 1000 ? clc : 1000; | |
82 | } | |
83 | ||
84 | /** | |
85 | * clockevents_delta2ns - Convert a latch value (device ticks) to nanoseconds | |
86 | * @latch: value to convert | |
87 | * @evt: pointer to clock event device descriptor | |
88 | * | |
89 | * Math helper, returns latch value converted to nanoseconds (bound checked) | |
90 | */ | |
91 | u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt) | |
92 | { | |
93 | return cev_delta2ns(latch, evt, false); | |
d316c57f | 94 | } |
c81fc2c3 | 95 | EXPORT_SYMBOL_GPL(clockevent_delta2ns); |
d316c57f TG |
96 | |
97 | /** | |
98 | * clockevents_set_mode - set the operating mode of a clock event device | |
99 | * @dev: device to modify | |
100 | * @mode: new mode | |
101 | * | |
102 | * Must be called with interrupts disabled ! | |
103 | */ | |
104 | void clockevents_set_mode(struct clock_event_device *dev, | |
105 | enum clock_event_mode mode) | |
106 | { | |
107 | if (dev->mode != mode) { | |
108 | dev->set_mode(mode, dev); | |
109 | dev->mode = mode; | |
2d68259d MD |
110 | |
111 | /* | |
112 | * A nsec2cyc multiplicator of 0 is invalid and we'd crash | |
113 | * on it, so fix it up and emit a warning: | |
114 | */ | |
115 | if (mode == CLOCK_EVT_MODE_ONESHOT) { | |
116 | if (unlikely(!dev->mult)) { | |
117 | dev->mult = 1; | |
118 | WARN_ON(1); | |
119 | } | |
120 | } | |
d316c57f TG |
121 | } |
122 | } | |
123 | ||
2344abbc TG |
124 | /** |
125 | * clockevents_shutdown - shutdown the device and clear next_event | |
126 | * @dev: device to shutdown | |
127 | */ | |
128 | void clockevents_shutdown(struct clock_event_device *dev) | |
129 | { | |
130 | clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN); | |
131 | dev->next_event.tv64 = KTIME_MAX; | |
132 | } | |
133 | ||
d1748302 MS |
134 | #ifdef CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST |
135 | ||
136 | /* Limit min_delta to a jiffie */ | |
137 | #define MIN_DELTA_LIMIT (NSEC_PER_SEC / HZ) | |
138 | ||
139 | /** | |
140 | * clockevents_increase_min_delta - raise minimum delta of a clock event device | |
141 | * @dev: device to increase the minimum delta | |
142 | * | |
143 | * Returns 0 on success, -ETIME when the minimum delta reached the limit. | |
144 | */ | |
145 | static int clockevents_increase_min_delta(struct clock_event_device *dev) | |
146 | { | |
147 | /* Nothing to do if we already reached the limit */ | |
148 | if (dev->min_delta_ns >= MIN_DELTA_LIMIT) { | |
149 | printk(KERN_WARNING "CE: Reprogramming failure. Giving up\n"); | |
150 | dev->next_event.tv64 = KTIME_MAX; | |
151 | return -ETIME; | |
152 | } | |
153 | ||
154 | if (dev->min_delta_ns < 5000) | |
155 | dev->min_delta_ns = 5000; | |
156 | else | |
157 | dev->min_delta_ns += dev->min_delta_ns >> 1; | |
158 | ||
159 | if (dev->min_delta_ns > MIN_DELTA_LIMIT) | |
160 | dev->min_delta_ns = MIN_DELTA_LIMIT; | |
161 | ||
162 | printk(KERN_WARNING "CE: %s increased min_delta_ns to %llu nsec\n", | |
163 | dev->name ? dev->name : "?", | |
164 | (unsigned long long) dev->min_delta_ns); | |
165 | return 0; | |
166 | } | |
167 | ||
168 | /** | |
169 | * clockevents_program_min_delta - Set clock event device to the minimum delay. | |
170 | * @dev: device to program | |
171 | * | |
172 | * Returns 0 on success, -ETIME when the retry loop failed. | |
173 | */ | |
174 | static int clockevents_program_min_delta(struct clock_event_device *dev) | |
175 | { | |
176 | unsigned long long clc; | |
177 | int64_t delta; | |
178 | int i; | |
179 | ||
180 | for (i = 0;;) { | |
181 | delta = dev->min_delta_ns; | |
182 | dev->next_event = ktime_add_ns(ktime_get(), delta); | |
183 | ||
184 | if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN) | |
185 | return 0; | |
186 | ||
187 | dev->retries++; | |
188 | clc = ((unsigned long long) delta * dev->mult) >> dev->shift; | |
189 | if (dev->set_next_event((unsigned long) clc, dev) == 0) | |
190 | return 0; | |
191 | ||
192 | if (++i > 2) { | |
193 | /* | |
194 | * We tried 3 times to program the device with the | |
195 | * given min_delta_ns. Try to increase the minimum | |
196 | * delta, if that fails as well get out of here. | |
197 | */ | |
198 | if (clockevents_increase_min_delta(dev)) | |
199 | return -ETIME; | |
200 | i = 0; | |
201 | } | |
202 | } | |
203 | } | |
204 | ||
205 | #else /* CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST */ | |
206 | ||
207 | /** | |
208 | * clockevents_program_min_delta - Set clock event device to the minimum delay. | |
209 | * @dev: device to program | |
210 | * | |
211 | * Returns 0 on success, -ETIME when the retry loop failed. | |
212 | */ | |
213 | static int clockevents_program_min_delta(struct clock_event_device *dev) | |
214 | { | |
215 | unsigned long long clc; | |
216 | int64_t delta; | |
217 | ||
218 | delta = dev->min_delta_ns; | |
219 | dev->next_event = ktime_add_ns(ktime_get(), delta); | |
220 | ||
221 | if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN) | |
222 | return 0; | |
223 | ||
224 | dev->retries++; | |
225 | clc = ((unsigned long long) delta * dev->mult) >> dev->shift; | |
226 | return dev->set_next_event((unsigned long) clc, dev); | |
227 | } | |
228 | ||
229 | #endif /* CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST */ | |
230 | ||
d316c57f TG |
231 | /** |
232 | * clockevents_program_event - Reprogram the clock event device. | |
d1748302 | 233 | * @dev: device to program |
d316c57f | 234 | * @expires: absolute expiry time (monotonic clock) |
d1748302 | 235 | * @force: program minimum delay if expires can not be set |
d316c57f TG |
236 | * |
237 | * Returns 0 on success, -ETIME when the event is in the past. | |
238 | */ | |
239 | int clockevents_program_event(struct clock_event_device *dev, ktime_t expires, | |
d1748302 | 240 | bool force) |
d316c57f TG |
241 | { |
242 | unsigned long long clc; | |
243 | int64_t delta; | |
d1748302 | 244 | int rc; |
d316c57f | 245 | |
167b1de3 TG |
246 | if (unlikely(expires.tv64 < 0)) { |
247 | WARN_ON_ONCE(1); | |
248 | return -ETIME; | |
249 | } | |
250 | ||
d316c57f TG |
251 | dev->next_event = expires; |
252 | ||
253 | if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN) | |
254 | return 0; | |
255 | ||
65516f8a MS |
256 | /* Shortcut for clockevent devices that can deal with ktime. */ |
257 | if (dev->features & CLOCK_EVT_FEAT_KTIME) | |
258 | return dev->set_next_ktime(expires, dev); | |
259 | ||
d1748302 MS |
260 | delta = ktime_to_ns(ktime_sub(expires, ktime_get())); |
261 | if (delta <= 0) | |
262 | return force ? clockevents_program_min_delta(dev) : -ETIME; | |
d316c57f | 263 | |
d1748302 MS |
264 | delta = min(delta, (int64_t) dev->max_delta_ns); |
265 | delta = max(delta, (int64_t) dev->min_delta_ns); | |
d316c57f | 266 | |
d1748302 MS |
267 | clc = ((unsigned long long) delta * dev->mult) >> dev->shift; |
268 | rc = dev->set_next_event((unsigned long) clc, dev); | |
269 | ||
270 | return (rc && force) ? clockevents_program_min_delta(dev) : rc; | |
d316c57f TG |
271 | } |
272 | ||
d316c57f | 273 | /* |
3eb05676 | 274 | * Called after a notify add to make devices available which were |
d316c57f TG |
275 | * released from the notifier call. |
276 | */ | |
277 | static void clockevents_notify_released(void) | |
278 | { | |
279 | struct clock_event_device *dev; | |
280 | ||
281 | while (!list_empty(&clockevents_released)) { | |
282 | dev = list_entry(clockevents_released.next, | |
283 | struct clock_event_device, list); | |
284 | list_del(&dev->list); | |
285 | list_add(&dev->list, &clockevent_devices); | |
7172a286 | 286 | tick_check_new_device(dev); |
d316c57f TG |
287 | } |
288 | } | |
289 | ||
03e13cf5 TG |
290 | /* |
291 | * Try to install a replacement clock event device | |
292 | */ | |
293 | static int clockevents_replace(struct clock_event_device *ced) | |
294 | { | |
295 | struct clock_event_device *dev, *newdev = NULL; | |
296 | ||
297 | list_for_each_entry(dev, &clockevent_devices, list) { | |
298 | if (dev == ced || dev->mode != CLOCK_EVT_MODE_UNUSED) | |
299 | continue; | |
300 | ||
301 | if (!tick_check_replacement(newdev, dev)) | |
302 | continue; | |
303 | ||
304 | if (!try_module_get(dev->owner)) | |
305 | continue; | |
306 | ||
307 | if (newdev) | |
308 | module_put(newdev->owner); | |
309 | newdev = dev; | |
310 | } | |
311 | if (newdev) { | |
312 | tick_install_replacement(newdev); | |
313 | list_del_init(&ced->list); | |
314 | } | |
315 | return newdev ? 0 : -EBUSY; | |
316 | } | |
317 | ||
318 | /* | |
319 | * Called with clockevents_mutex and clockevents_lock held | |
320 | */ | |
321 | static int __clockevents_try_unbind(struct clock_event_device *ced, int cpu) | |
322 | { | |
323 | /* Fast track. Device is unused */ | |
324 | if (ced->mode == CLOCK_EVT_MODE_UNUSED) { | |
325 | list_del_init(&ced->list); | |
326 | return 0; | |
327 | } | |
328 | ||
329 | return ced == per_cpu(tick_cpu_device, cpu).evtdev ? -EAGAIN : -EBUSY; | |
330 | } | |
331 | ||
332 | /* | |
333 | * SMP function call to unbind a device | |
334 | */ | |
335 | static void __clockevents_unbind(void *arg) | |
336 | { | |
337 | struct ce_unbind *cu = arg; | |
338 | int res; | |
339 | ||
340 | raw_spin_lock(&clockevents_lock); | |
341 | res = __clockevents_try_unbind(cu->ce, smp_processor_id()); | |
342 | if (res == -EAGAIN) | |
343 | res = clockevents_replace(cu->ce); | |
344 | cu->res = res; | |
345 | raw_spin_unlock(&clockevents_lock); | |
346 | } | |
347 | ||
348 | /* | |
349 | * Issues smp function call to unbind a per cpu device. Called with | |
350 | * clockevents_mutex held. | |
351 | */ | |
352 | static int clockevents_unbind(struct clock_event_device *ced, int cpu) | |
353 | { | |
354 | struct ce_unbind cu = { .ce = ced, .res = -ENODEV }; | |
355 | ||
356 | smp_call_function_single(cpu, __clockevents_unbind, &cu, 1); | |
357 | return cu.res; | |
358 | } | |
359 | ||
360 | /* | |
361 | * Unbind a clockevents device. | |
362 | */ | |
363 | int clockevents_unbind_device(struct clock_event_device *ced, int cpu) | |
364 | { | |
365 | int ret; | |
366 | ||
367 | mutex_lock(&clockevents_mutex); | |
368 | ret = clockevents_unbind(ced, cpu); | |
369 | mutex_unlock(&clockevents_mutex); | |
370 | return ret; | |
371 | } | |
372 | EXPORT_SYMBOL_GPL(clockevents_unbind); | |
373 | ||
d316c57f TG |
374 | /** |
375 | * clockevents_register_device - register a clock event device | |
376 | * @dev: device to register | |
377 | */ | |
378 | void clockevents_register_device(struct clock_event_device *dev) | |
379 | { | |
f833bab8 SS |
380 | unsigned long flags; |
381 | ||
d316c57f | 382 | BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); |
1b054b67 TG |
383 | if (!dev->cpumask) { |
384 | WARN_ON(num_possible_cpus() > 1); | |
385 | dev->cpumask = cpumask_of(smp_processor_id()); | |
386 | } | |
320ab2b0 | 387 | |
b5f91da0 | 388 | raw_spin_lock_irqsave(&clockevents_lock, flags); |
d316c57f TG |
389 | |
390 | list_add(&dev->list, &clockevent_devices); | |
7172a286 | 391 | tick_check_new_device(dev); |
d316c57f TG |
392 | clockevents_notify_released(); |
393 | ||
b5f91da0 | 394 | raw_spin_unlock_irqrestore(&clockevents_lock, flags); |
d316c57f | 395 | } |
c81fc2c3 | 396 | EXPORT_SYMBOL_GPL(clockevents_register_device); |
d316c57f | 397 | |
e5400321 | 398 | void clockevents_config(struct clock_event_device *dev, u32 freq) |
57f0fcbe | 399 | { |
c0e299b1 | 400 | u64 sec; |
57f0fcbe TG |
401 | |
402 | if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT)) | |
403 | return; | |
404 | ||
405 | /* | |
406 | * Calculate the maximum number of seconds we can sleep. Limit | |
407 | * to 10 minutes for hardware which can program more than | |
408 | * 32bit ticks so we still get reasonable conversion values. | |
409 | */ | |
410 | sec = dev->max_delta_ticks; | |
411 | do_div(sec, freq); | |
412 | if (!sec) | |
413 | sec = 1; | |
414 | else if (sec > 600 && dev->max_delta_ticks > UINT_MAX) | |
415 | sec = 600; | |
416 | ||
417 | clockevents_calc_mult_shift(dev, freq, sec); | |
97b94106 TG |
418 | dev->min_delta_ns = cev_delta2ns(dev->min_delta_ticks, dev, false); |
419 | dev->max_delta_ns = cev_delta2ns(dev->max_delta_ticks, dev, true); | |
57f0fcbe TG |
420 | } |
421 | ||
422 | /** | |
423 | * clockevents_config_and_register - Configure and register a clock event device | |
424 | * @dev: device to register | |
425 | * @freq: The clock frequency | |
426 | * @min_delta: The minimum clock ticks to program in oneshot mode | |
427 | * @max_delta: The maximum clock ticks to program in oneshot mode | |
428 | * | |
429 | * min/max_delta can be 0 for devices which do not support oneshot mode. | |
430 | */ | |
431 | void clockevents_config_and_register(struct clock_event_device *dev, | |
432 | u32 freq, unsigned long min_delta, | |
433 | unsigned long max_delta) | |
434 | { | |
435 | dev->min_delta_ticks = min_delta; | |
436 | dev->max_delta_ticks = max_delta; | |
437 | clockevents_config(dev, freq); | |
438 | clockevents_register_device(dev); | |
439 | } | |
c35ef95c | 440 | EXPORT_SYMBOL_GPL(clockevents_config_and_register); |
57f0fcbe | 441 | |
627ee794 TG |
442 | int __clockevents_update_freq(struct clock_event_device *dev, u32 freq) |
443 | { | |
444 | clockevents_config(dev, freq); | |
445 | ||
fe79a9ba SB |
446 | if (dev->mode == CLOCK_EVT_MODE_ONESHOT) |
447 | return clockevents_program_event(dev, dev->next_event, false); | |
448 | ||
449 | if (dev->mode == CLOCK_EVT_MODE_PERIODIC) | |
450 | dev->set_mode(CLOCK_EVT_MODE_PERIODIC, dev); | |
627ee794 | 451 | |
fe79a9ba | 452 | return 0; |
627ee794 TG |
453 | } |
454 | ||
80b816b7 TG |
455 | /** |
456 | * clockevents_update_freq - Update frequency and reprogram a clock event device. | |
457 | * @dev: device to modify | |
458 | * @freq: new device frequency | |
459 | * | |
460 | * Reconfigure and reprogram a clock event device in oneshot | |
461 | * mode. Must be called on the cpu for which the device delivers per | |
627ee794 TG |
462 | * cpu timer events. If called for the broadcast device the core takes |
463 | * care of serialization. | |
464 | * | |
465 | * Returns 0 on success, -ETIME when the event is in the past. | |
80b816b7 TG |
466 | */ |
467 | int clockevents_update_freq(struct clock_event_device *dev, u32 freq) | |
468 | { | |
627ee794 TG |
469 | unsigned long flags; |
470 | int ret; | |
80b816b7 | 471 | |
627ee794 TG |
472 | local_irq_save(flags); |
473 | ret = tick_broadcast_update_freq(dev, freq); | |
474 | if (ret == -ENODEV) | |
475 | ret = __clockevents_update_freq(dev, freq); | |
476 | local_irq_restore(flags); | |
477 | return ret; | |
80b816b7 TG |
478 | } |
479 | ||
d316c57f TG |
480 | /* |
481 | * Noop handler when we shut down an event device | |
482 | */ | |
7c1e7689 | 483 | void clockevents_handle_noop(struct clock_event_device *dev) |
d316c57f TG |
484 | { |
485 | } | |
486 | ||
487 | /** | |
488 | * clockevents_exchange_device - release and request clock devices | |
489 | * @old: device to release (can be NULL) | |
490 | * @new: device to request (can be NULL) | |
491 | * | |
492 | * Called from the notifier chain. clockevents_lock is held already | |
493 | */ | |
494 | void clockevents_exchange_device(struct clock_event_device *old, | |
495 | struct clock_event_device *new) | |
496 | { | |
497 | unsigned long flags; | |
498 | ||
499 | local_irq_save(flags); | |
500 | /* | |
501 | * Caller releases a clock event device. We queue it into the | |
502 | * released list and do a notify add later. | |
503 | */ | |
504 | if (old) { | |
ccf33d68 | 505 | module_put(old->owner); |
d316c57f TG |
506 | clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED); |
507 | list_del(&old->list); | |
508 | list_add(&old->list, &clockevents_released); | |
509 | } | |
510 | ||
511 | if (new) { | |
512 | BUG_ON(new->mode != CLOCK_EVT_MODE_UNUSED); | |
2344abbc | 513 | clockevents_shutdown(new); |
d316c57f TG |
514 | } |
515 | local_irq_restore(flags); | |
516 | } | |
517 | ||
adc78e6b RW |
518 | /** |
519 | * clockevents_suspend - suspend clock devices | |
520 | */ | |
521 | void clockevents_suspend(void) | |
522 | { | |
523 | struct clock_event_device *dev; | |
524 | ||
525 | list_for_each_entry_reverse(dev, &clockevent_devices, list) | |
526 | if (dev->suspend) | |
527 | dev->suspend(dev); | |
528 | } | |
529 | ||
530 | /** | |
531 | * clockevents_resume - resume clock devices | |
532 | */ | |
533 | void clockevents_resume(void) | |
534 | { | |
535 | struct clock_event_device *dev; | |
536 | ||
537 | list_for_each_entry(dev, &clockevent_devices, list) | |
538 | if (dev->resume) | |
539 | dev->resume(dev); | |
540 | } | |
541 | ||
de68d9b1 | 542 | #ifdef CONFIG_GENERIC_CLOCKEVENTS |
d316c57f TG |
543 | /** |
544 | * clockevents_notify - notification about relevant events | |
da7e6f45 | 545 | * Returns 0 on success, any other value on error |
d316c57f | 546 | */ |
da7e6f45 | 547 | int clockevents_notify(unsigned long reason, void *arg) |
d316c57f | 548 | { |
bb6eddf7 | 549 | struct clock_event_device *dev, *tmp; |
f833bab8 | 550 | unsigned long flags; |
da7e6f45 | 551 | int cpu, ret = 0; |
0b858e6f | 552 | |
b5f91da0 | 553 | raw_spin_lock_irqsave(&clockevents_lock, flags); |
d316c57f TG |
554 | |
555 | switch (reason) { | |
8c53daf6 TG |
556 | case CLOCK_EVT_NOTIFY_BROADCAST_ON: |
557 | case CLOCK_EVT_NOTIFY_BROADCAST_OFF: | |
558 | case CLOCK_EVT_NOTIFY_BROADCAST_FORCE: | |
559 | tick_broadcast_on_off(reason, arg); | |
560 | break; | |
561 | ||
562 | case CLOCK_EVT_NOTIFY_BROADCAST_ENTER: | |
563 | case CLOCK_EVT_NOTIFY_BROADCAST_EXIT: | |
da7e6f45 | 564 | ret = tick_broadcast_oneshot_control(reason); |
8c53daf6 TG |
565 | break; |
566 | ||
567 | case CLOCK_EVT_NOTIFY_CPU_DYING: | |
568 | tick_handover_do_timer(arg); | |
569 | break; | |
570 | ||
571 | case CLOCK_EVT_NOTIFY_SUSPEND: | |
572 | tick_suspend(); | |
573 | tick_suspend_broadcast(); | |
574 | break; | |
575 | ||
576 | case CLOCK_EVT_NOTIFY_RESUME: | |
577 | tick_resume(); | |
578 | break; | |
579 | ||
d316c57f | 580 | case CLOCK_EVT_NOTIFY_CPU_DEAD: |
8c53daf6 TG |
581 | tick_shutdown_broadcast_oneshot(arg); |
582 | tick_shutdown_broadcast(arg); | |
583 | tick_shutdown(arg); | |
d316c57f TG |
584 | /* |
585 | * Unregister the clock event devices which were | |
586 | * released from the users in the notify chain. | |
587 | */ | |
bb6eddf7 TG |
588 | list_for_each_entry_safe(dev, tmp, &clockevents_released, list) |
589 | list_del(&dev->list); | |
590 | /* | |
591 | * Now check whether the CPU has left unused per cpu devices | |
592 | */ | |
593 | cpu = *((int *)arg); | |
594 | list_for_each_entry_safe(dev, tmp, &clockevent_devices, list) { | |
595 | if (cpumask_test_cpu(cpu, dev->cpumask) && | |
ea9d8e3f XF |
596 | cpumask_weight(dev->cpumask) == 1 && |
597 | !tick_is_broadcast_device(dev)) { | |
bb6eddf7 TG |
598 | BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); |
599 | list_del(&dev->list); | |
600 | } | |
601 | } | |
d316c57f TG |
602 | break; |
603 | default: | |
604 | break; | |
605 | } | |
b5f91da0 | 606 | raw_spin_unlock_irqrestore(&clockevents_lock, flags); |
da7e6f45 | 607 | return ret; |
d316c57f TG |
608 | } |
609 | EXPORT_SYMBOL_GPL(clockevents_notify); | |
501f8670 TG |
610 | |
611 | #ifdef CONFIG_SYSFS | |
612 | struct bus_type clockevents_subsys = { | |
613 | .name = "clockevents", | |
614 | .dev_name = "clockevent", | |
615 | }; | |
616 | ||
617 | static DEFINE_PER_CPU(struct device, tick_percpu_dev); | |
618 | static struct tick_device *tick_get_tick_dev(struct device *dev); | |
619 | ||
620 | static ssize_t sysfs_show_current_tick_dev(struct device *dev, | |
621 | struct device_attribute *attr, | |
622 | char *buf) | |
623 | { | |
624 | struct tick_device *td; | |
625 | ssize_t count = 0; | |
626 | ||
627 | raw_spin_lock_irq(&clockevents_lock); | |
628 | td = tick_get_tick_dev(dev); | |
629 | if (td && td->evtdev) | |
630 | count = snprintf(buf, PAGE_SIZE, "%s\n", td->evtdev->name); | |
631 | raw_spin_unlock_irq(&clockevents_lock); | |
632 | return count; | |
633 | } | |
634 | static DEVICE_ATTR(current_device, 0444, sysfs_show_current_tick_dev, NULL); | |
635 | ||
03e13cf5 TG |
636 | /* We don't support the abomination of removable broadcast devices */ |
637 | static ssize_t sysfs_unbind_tick_dev(struct device *dev, | |
638 | struct device_attribute *attr, | |
639 | const char *buf, size_t count) | |
640 | { | |
641 | char name[CS_NAME_LEN]; | |
891292a7 | 642 | ssize_t ret = sysfs_get_uname(buf, name, count); |
03e13cf5 TG |
643 | struct clock_event_device *ce; |
644 | ||
645 | if (ret < 0) | |
646 | return ret; | |
647 | ||
648 | ret = -ENODEV; | |
649 | mutex_lock(&clockevents_mutex); | |
650 | raw_spin_lock_irq(&clockevents_lock); | |
651 | list_for_each_entry(ce, &clockevent_devices, list) { | |
652 | if (!strcmp(ce->name, name)) { | |
653 | ret = __clockevents_try_unbind(ce, dev->id); | |
654 | break; | |
655 | } | |
656 | } | |
657 | raw_spin_unlock_irq(&clockevents_lock); | |
658 | /* | |
659 | * We hold clockevents_mutex, so ce can't go away | |
660 | */ | |
661 | if (ret == -EAGAIN) | |
662 | ret = clockevents_unbind(ce, dev->id); | |
663 | mutex_unlock(&clockevents_mutex); | |
664 | return ret ? ret : count; | |
665 | } | |
666 | static DEVICE_ATTR(unbind_device, 0200, NULL, sysfs_unbind_tick_dev); | |
667 | ||
501f8670 TG |
668 | #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST |
669 | static struct device tick_bc_dev = { | |
670 | .init_name = "broadcast", | |
671 | .id = 0, | |
672 | .bus = &clockevents_subsys, | |
673 | }; | |
674 | ||
675 | static struct tick_device *tick_get_tick_dev(struct device *dev) | |
676 | { | |
677 | return dev == &tick_bc_dev ? tick_get_broadcast_device() : | |
678 | &per_cpu(tick_cpu_device, dev->id); | |
679 | } | |
680 | ||
681 | static __init int tick_broadcast_init_sysfs(void) | |
682 | { | |
683 | int err = device_register(&tick_bc_dev); | |
684 | ||
685 | if (!err) | |
686 | err = device_create_file(&tick_bc_dev, &dev_attr_current_device); | |
687 | return err; | |
688 | } | |
689 | #else | |
690 | static struct tick_device *tick_get_tick_dev(struct device *dev) | |
691 | { | |
692 | return &per_cpu(tick_cpu_device, dev->id); | |
693 | } | |
694 | static inline int tick_broadcast_init_sysfs(void) { return 0; } | |
de68d9b1 | 695 | #endif |
501f8670 TG |
696 | |
697 | static int __init tick_init_sysfs(void) | |
698 | { | |
699 | int cpu; | |
700 | ||
701 | for_each_possible_cpu(cpu) { | |
702 | struct device *dev = &per_cpu(tick_percpu_dev, cpu); | |
703 | int err; | |
704 | ||
705 | dev->id = cpu; | |
706 | dev->bus = &clockevents_subsys; | |
707 | err = device_register(dev); | |
708 | if (!err) | |
709 | err = device_create_file(dev, &dev_attr_current_device); | |
03e13cf5 TG |
710 | if (!err) |
711 | err = device_create_file(dev, &dev_attr_unbind_device); | |
501f8670 TG |
712 | if (err) |
713 | return err; | |
714 | } | |
715 | return tick_broadcast_init_sysfs(); | |
716 | } | |
717 | ||
718 | static int __init clockevents_init_sysfs(void) | |
719 | { | |
720 | int err = subsys_system_register(&clockevents_subsys, NULL); | |
721 | ||
722 | if (!err) | |
723 | err = tick_init_sysfs(); | |
724 | return err; | |
725 | } | |
726 | device_initcall(clockevents_init_sysfs); | |
727 | #endif /* SYSFS */ | |
728 | ||
729 | #endif /* GENERIC_CLOCK_EVENTS */ |