Commit | Line | Data |
---|---|---|
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) { | |
504d5874 JK |
149 | printk_deferred(KERN_WARNING |
150 | "CE: Reprogramming failure. Giving up\n"); | |
d1748302 MS |
151 | dev->next_event.tv64 = KTIME_MAX; |
152 | return -ETIME; | |
153 | } | |
154 | ||
155 | if (dev->min_delta_ns < 5000) | |
156 | dev->min_delta_ns = 5000; | |
157 | else | |
158 | dev->min_delta_ns += dev->min_delta_ns >> 1; | |
159 | ||
160 | if (dev->min_delta_ns > MIN_DELTA_LIMIT) | |
161 | dev->min_delta_ns = MIN_DELTA_LIMIT; | |
162 | ||
504d5874 JK |
163 | printk_deferred(KERN_WARNING |
164 | "CE: %s increased min_delta_ns to %llu nsec\n", | |
165 | dev->name ? dev->name : "?", | |
166 | (unsigned long long) dev->min_delta_ns); | |
d1748302 MS |
167 | return 0; |
168 | } | |
169 | ||
170 | /** | |
171 | * clockevents_program_min_delta - Set clock event device to the minimum delay. | |
172 | * @dev: device to program | |
173 | * | |
174 | * Returns 0 on success, -ETIME when the retry loop failed. | |
175 | */ | |
176 | static int clockevents_program_min_delta(struct clock_event_device *dev) | |
177 | { | |
178 | unsigned long long clc; | |
179 | int64_t delta; | |
180 | int i; | |
181 | ||
182 | for (i = 0;;) { | |
183 | delta = dev->min_delta_ns; | |
184 | dev->next_event = ktime_add_ns(ktime_get(), delta); | |
185 | ||
186 | if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN) | |
187 | return 0; | |
188 | ||
189 | dev->retries++; | |
190 | clc = ((unsigned long long) delta * dev->mult) >> dev->shift; | |
191 | if (dev->set_next_event((unsigned long) clc, dev) == 0) | |
192 | return 0; | |
193 | ||
194 | if (++i > 2) { | |
195 | /* | |
196 | * We tried 3 times to program the device with the | |
197 | * given min_delta_ns. Try to increase the minimum | |
198 | * delta, if that fails as well get out of here. | |
199 | */ | |
200 | if (clockevents_increase_min_delta(dev)) | |
201 | return -ETIME; | |
202 | i = 0; | |
203 | } | |
204 | } | |
205 | } | |
206 | ||
207 | #else /* CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST */ | |
208 | ||
209 | /** | |
210 | * clockevents_program_min_delta - Set clock event device to the minimum delay. | |
211 | * @dev: device to program | |
212 | * | |
213 | * Returns 0 on success, -ETIME when the retry loop failed. | |
214 | */ | |
215 | static int clockevents_program_min_delta(struct clock_event_device *dev) | |
216 | { | |
217 | unsigned long long clc; | |
218 | int64_t delta; | |
219 | ||
220 | delta = dev->min_delta_ns; | |
221 | dev->next_event = ktime_add_ns(ktime_get(), delta); | |
222 | ||
223 | if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN) | |
224 | return 0; | |
225 | ||
226 | dev->retries++; | |
227 | clc = ((unsigned long long) delta * dev->mult) >> dev->shift; | |
228 | return dev->set_next_event((unsigned long) clc, dev); | |
229 | } | |
230 | ||
231 | #endif /* CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST */ | |
232 | ||
d316c57f TG |
233 | /** |
234 | * clockevents_program_event - Reprogram the clock event device. | |
d1748302 | 235 | * @dev: device to program |
d316c57f | 236 | * @expires: absolute expiry time (monotonic clock) |
d1748302 | 237 | * @force: program minimum delay if expires can not be set |
d316c57f TG |
238 | * |
239 | * Returns 0 on success, -ETIME when the event is in the past. | |
240 | */ | |
241 | int clockevents_program_event(struct clock_event_device *dev, ktime_t expires, | |
d1748302 | 242 | bool force) |
d316c57f TG |
243 | { |
244 | unsigned long long clc; | |
245 | int64_t delta; | |
d1748302 | 246 | int rc; |
d316c57f | 247 | |
167b1de3 TG |
248 | if (unlikely(expires.tv64 < 0)) { |
249 | WARN_ON_ONCE(1); | |
250 | return -ETIME; | |
251 | } | |
252 | ||
d316c57f TG |
253 | dev->next_event = expires; |
254 | ||
255 | if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN) | |
256 | return 0; | |
257 | ||
65516f8a MS |
258 | /* Shortcut for clockevent devices that can deal with ktime. */ |
259 | if (dev->features & CLOCK_EVT_FEAT_KTIME) | |
260 | return dev->set_next_ktime(expires, dev); | |
261 | ||
d1748302 MS |
262 | delta = ktime_to_ns(ktime_sub(expires, ktime_get())); |
263 | if (delta <= 0) | |
264 | return force ? clockevents_program_min_delta(dev) : -ETIME; | |
d316c57f | 265 | |
d1748302 MS |
266 | delta = min(delta, (int64_t) dev->max_delta_ns); |
267 | delta = max(delta, (int64_t) dev->min_delta_ns); | |
d316c57f | 268 | |
d1748302 MS |
269 | clc = ((unsigned long long) delta * dev->mult) >> dev->shift; |
270 | rc = dev->set_next_event((unsigned long) clc, dev); | |
271 | ||
272 | return (rc && force) ? clockevents_program_min_delta(dev) : rc; | |
d316c57f TG |
273 | } |
274 | ||
d316c57f | 275 | /* |
3eb05676 | 276 | * Called after a notify add to make devices available which were |
d316c57f TG |
277 | * released from the notifier call. |
278 | */ | |
279 | static void clockevents_notify_released(void) | |
280 | { | |
281 | struct clock_event_device *dev; | |
282 | ||
283 | while (!list_empty(&clockevents_released)) { | |
284 | dev = list_entry(clockevents_released.next, | |
285 | struct clock_event_device, list); | |
286 | list_del(&dev->list); | |
287 | list_add(&dev->list, &clockevent_devices); | |
7172a286 | 288 | tick_check_new_device(dev); |
d316c57f TG |
289 | } |
290 | } | |
291 | ||
03e13cf5 TG |
292 | /* |
293 | * Try to install a replacement clock event device | |
294 | */ | |
295 | static int clockevents_replace(struct clock_event_device *ced) | |
296 | { | |
297 | struct clock_event_device *dev, *newdev = NULL; | |
298 | ||
299 | list_for_each_entry(dev, &clockevent_devices, list) { | |
300 | if (dev == ced || dev->mode != CLOCK_EVT_MODE_UNUSED) | |
301 | continue; | |
302 | ||
303 | if (!tick_check_replacement(newdev, dev)) | |
304 | continue; | |
305 | ||
306 | if (!try_module_get(dev->owner)) | |
307 | continue; | |
308 | ||
309 | if (newdev) | |
310 | module_put(newdev->owner); | |
311 | newdev = dev; | |
312 | } | |
313 | if (newdev) { | |
314 | tick_install_replacement(newdev); | |
315 | list_del_init(&ced->list); | |
316 | } | |
317 | return newdev ? 0 : -EBUSY; | |
318 | } | |
319 | ||
320 | /* | |
321 | * Called with clockevents_mutex and clockevents_lock held | |
322 | */ | |
323 | static int __clockevents_try_unbind(struct clock_event_device *ced, int cpu) | |
324 | { | |
325 | /* Fast track. Device is unused */ | |
326 | if (ced->mode == CLOCK_EVT_MODE_UNUSED) { | |
327 | list_del_init(&ced->list); | |
328 | return 0; | |
329 | } | |
330 | ||
331 | return ced == per_cpu(tick_cpu_device, cpu).evtdev ? -EAGAIN : -EBUSY; | |
332 | } | |
333 | ||
334 | /* | |
335 | * SMP function call to unbind a device | |
336 | */ | |
337 | static void __clockevents_unbind(void *arg) | |
338 | { | |
339 | struct ce_unbind *cu = arg; | |
340 | int res; | |
341 | ||
342 | raw_spin_lock(&clockevents_lock); | |
343 | res = __clockevents_try_unbind(cu->ce, smp_processor_id()); | |
344 | if (res == -EAGAIN) | |
345 | res = clockevents_replace(cu->ce); | |
346 | cu->res = res; | |
347 | raw_spin_unlock(&clockevents_lock); | |
348 | } | |
349 | ||
350 | /* | |
351 | * Issues smp function call to unbind a per cpu device. Called with | |
352 | * clockevents_mutex held. | |
353 | */ | |
354 | static int clockevents_unbind(struct clock_event_device *ced, int cpu) | |
355 | { | |
356 | struct ce_unbind cu = { .ce = ced, .res = -ENODEV }; | |
357 | ||
358 | smp_call_function_single(cpu, __clockevents_unbind, &cu, 1); | |
359 | return cu.res; | |
360 | } | |
361 | ||
362 | /* | |
363 | * Unbind a clockevents device. | |
364 | */ | |
365 | int clockevents_unbind_device(struct clock_event_device *ced, int cpu) | |
366 | { | |
367 | int ret; | |
368 | ||
369 | mutex_lock(&clockevents_mutex); | |
370 | ret = clockevents_unbind(ced, cpu); | |
371 | mutex_unlock(&clockevents_mutex); | |
372 | return ret; | |
373 | } | |
374 | EXPORT_SYMBOL_GPL(clockevents_unbind); | |
375 | ||
d316c57f TG |
376 | /** |
377 | * clockevents_register_device - register a clock event device | |
378 | * @dev: device to register | |
379 | */ | |
380 | void clockevents_register_device(struct clock_event_device *dev) | |
381 | { | |
f833bab8 SS |
382 | unsigned long flags; |
383 | ||
d316c57f | 384 | BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); |
1b054b67 TG |
385 | if (!dev->cpumask) { |
386 | WARN_ON(num_possible_cpus() > 1); | |
387 | dev->cpumask = cpumask_of(smp_processor_id()); | |
388 | } | |
320ab2b0 | 389 | |
b5f91da0 | 390 | raw_spin_lock_irqsave(&clockevents_lock, flags); |
d316c57f TG |
391 | |
392 | list_add(&dev->list, &clockevent_devices); | |
7172a286 | 393 | tick_check_new_device(dev); |
d316c57f TG |
394 | clockevents_notify_released(); |
395 | ||
b5f91da0 | 396 | raw_spin_unlock_irqrestore(&clockevents_lock, flags); |
d316c57f | 397 | } |
c81fc2c3 | 398 | EXPORT_SYMBOL_GPL(clockevents_register_device); |
d316c57f | 399 | |
e5400321 | 400 | void clockevents_config(struct clock_event_device *dev, u32 freq) |
57f0fcbe | 401 | { |
c0e299b1 | 402 | u64 sec; |
57f0fcbe TG |
403 | |
404 | if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT)) | |
405 | return; | |
406 | ||
407 | /* | |
408 | * Calculate the maximum number of seconds we can sleep. Limit | |
409 | * to 10 minutes for hardware which can program more than | |
410 | * 32bit ticks so we still get reasonable conversion values. | |
411 | */ | |
412 | sec = dev->max_delta_ticks; | |
413 | do_div(sec, freq); | |
414 | if (!sec) | |
415 | sec = 1; | |
416 | else if (sec > 600 && dev->max_delta_ticks > UINT_MAX) | |
417 | sec = 600; | |
418 | ||
419 | clockevents_calc_mult_shift(dev, freq, sec); | |
97b94106 TG |
420 | dev->min_delta_ns = cev_delta2ns(dev->min_delta_ticks, dev, false); |
421 | dev->max_delta_ns = cev_delta2ns(dev->max_delta_ticks, dev, true); | |
57f0fcbe TG |
422 | } |
423 | ||
424 | /** | |
425 | * clockevents_config_and_register - Configure and register a clock event device | |
426 | * @dev: device to register | |
427 | * @freq: The clock frequency | |
428 | * @min_delta: The minimum clock ticks to program in oneshot mode | |
429 | * @max_delta: The maximum clock ticks to program in oneshot mode | |
430 | * | |
431 | * min/max_delta can be 0 for devices which do not support oneshot mode. | |
432 | */ | |
433 | void clockevents_config_and_register(struct clock_event_device *dev, | |
434 | u32 freq, unsigned long min_delta, | |
435 | unsigned long max_delta) | |
436 | { | |
437 | dev->min_delta_ticks = min_delta; | |
438 | dev->max_delta_ticks = max_delta; | |
439 | clockevents_config(dev, freq); | |
440 | clockevents_register_device(dev); | |
441 | } | |
c35ef95c | 442 | EXPORT_SYMBOL_GPL(clockevents_config_and_register); |
57f0fcbe | 443 | |
627ee794 TG |
444 | int __clockevents_update_freq(struct clock_event_device *dev, u32 freq) |
445 | { | |
446 | clockevents_config(dev, freq); | |
447 | ||
fe79a9ba SB |
448 | if (dev->mode == CLOCK_EVT_MODE_ONESHOT) |
449 | return clockevents_program_event(dev, dev->next_event, false); | |
450 | ||
451 | if (dev->mode == CLOCK_EVT_MODE_PERIODIC) | |
452 | dev->set_mode(CLOCK_EVT_MODE_PERIODIC, dev); | |
627ee794 | 453 | |
fe79a9ba | 454 | return 0; |
627ee794 TG |
455 | } |
456 | ||
80b816b7 TG |
457 | /** |
458 | * clockevents_update_freq - Update frequency and reprogram a clock event device. | |
459 | * @dev: device to modify | |
460 | * @freq: new device frequency | |
461 | * | |
462 | * Reconfigure and reprogram a clock event device in oneshot | |
463 | * mode. Must be called on the cpu for which the device delivers per | |
627ee794 TG |
464 | * cpu timer events. If called for the broadcast device the core takes |
465 | * care of serialization. | |
466 | * | |
467 | * Returns 0 on success, -ETIME when the event is in the past. | |
80b816b7 TG |
468 | */ |
469 | int clockevents_update_freq(struct clock_event_device *dev, u32 freq) | |
470 | { | |
627ee794 TG |
471 | unsigned long flags; |
472 | int ret; | |
80b816b7 | 473 | |
627ee794 TG |
474 | local_irq_save(flags); |
475 | ret = tick_broadcast_update_freq(dev, freq); | |
476 | if (ret == -ENODEV) | |
477 | ret = __clockevents_update_freq(dev, freq); | |
478 | local_irq_restore(flags); | |
479 | return ret; | |
80b816b7 TG |
480 | } |
481 | ||
d316c57f TG |
482 | /* |
483 | * Noop handler when we shut down an event device | |
484 | */ | |
7c1e7689 | 485 | void clockevents_handle_noop(struct clock_event_device *dev) |
d316c57f TG |
486 | { |
487 | } | |
488 | ||
489 | /** | |
490 | * clockevents_exchange_device - release and request clock devices | |
491 | * @old: device to release (can be NULL) | |
492 | * @new: device to request (can be NULL) | |
493 | * | |
494 | * Called from the notifier chain. clockevents_lock is held already | |
495 | */ | |
496 | void clockevents_exchange_device(struct clock_event_device *old, | |
497 | struct clock_event_device *new) | |
498 | { | |
499 | unsigned long flags; | |
500 | ||
501 | local_irq_save(flags); | |
502 | /* | |
503 | * Caller releases a clock event device. We queue it into the | |
504 | * released list and do a notify add later. | |
505 | */ | |
506 | if (old) { | |
ccf33d68 | 507 | module_put(old->owner); |
d316c57f TG |
508 | clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED); |
509 | list_del(&old->list); | |
510 | list_add(&old->list, &clockevents_released); | |
511 | } | |
512 | ||
513 | if (new) { | |
514 | BUG_ON(new->mode != CLOCK_EVT_MODE_UNUSED); | |
2344abbc | 515 | clockevents_shutdown(new); |
d316c57f TG |
516 | } |
517 | local_irq_restore(flags); | |
518 | } | |
519 | ||
adc78e6b RW |
520 | /** |
521 | * clockevents_suspend - suspend clock devices | |
522 | */ | |
523 | void clockevents_suspend(void) | |
524 | { | |
525 | struct clock_event_device *dev; | |
526 | ||
527 | list_for_each_entry_reverse(dev, &clockevent_devices, list) | |
528 | if (dev->suspend) | |
529 | dev->suspend(dev); | |
530 | } | |
531 | ||
532 | /** | |
533 | * clockevents_resume - resume clock devices | |
534 | */ | |
535 | void clockevents_resume(void) | |
536 | { | |
537 | struct clock_event_device *dev; | |
538 | ||
539 | list_for_each_entry(dev, &clockevent_devices, list) | |
540 | if (dev->resume) | |
541 | dev->resume(dev); | |
542 | } | |
543 | ||
de68d9b1 | 544 | #ifdef CONFIG_GENERIC_CLOCKEVENTS |
d316c57f TG |
545 | /** |
546 | * clockevents_notify - notification about relevant events | |
da7e6f45 | 547 | * Returns 0 on success, any other value on error |
d316c57f | 548 | */ |
da7e6f45 | 549 | int clockevents_notify(unsigned long reason, void *arg) |
d316c57f | 550 | { |
bb6eddf7 | 551 | struct clock_event_device *dev, *tmp; |
f833bab8 | 552 | unsigned long flags; |
da7e6f45 | 553 | int cpu, ret = 0; |
0b858e6f | 554 | |
b5f91da0 | 555 | raw_spin_lock_irqsave(&clockevents_lock, flags); |
d316c57f TG |
556 | |
557 | switch (reason) { | |
8c53daf6 TG |
558 | case CLOCK_EVT_NOTIFY_BROADCAST_ON: |
559 | case CLOCK_EVT_NOTIFY_BROADCAST_OFF: | |
560 | case CLOCK_EVT_NOTIFY_BROADCAST_FORCE: | |
561 | tick_broadcast_on_off(reason, arg); | |
562 | break; | |
563 | ||
564 | case CLOCK_EVT_NOTIFY_BROADCAST_ENTER: | |
565 | case CLOCK_EVT_NOTIFY_BROADCAST_EXIT: | |
da7e6f45 | 566 | ret = tick_broadcast_oneshot_control(reason); |
8c53daf6 TG |
567 | break; |
568 | ||
569 | case CLOCK_EVT_NOTIFY_CPU_DYING: | |
570 | tick_handover_do_timer(arg); | |
571 | break; | |
572 | ||
573 | case CLOCK_EVT_NOTIFY_SUSPEND: | |
574 | tick_suspend(); | |
575 | tick_suspend_broadcast(); | |
576 | break; | |
577 | ||
578 | case CLOCK_EVT_NOTIFY_RESUME: | |
579 | tick_resume(); | |
580 | break; | |
581 | ||
d316c57f | 582 | case CLOCK_EVT_NOTIFY_CPU_DEAD: |
8c53daf6 TG |
583 | tick_shutdown_broadcast_oneshot(arg); |
584 | tick_shutdown_broadcast(arg); | |
585 | tick_shutdown(arg); | |
d316c57f TG |
586 | /* |
587 | * Unregister the clock event devices which were | |
588 | * released from the users in the notify chain. | |
589 | */ | |
bb6eddf7 TG |
590 | list_for_each_entry_safe(dev, tmp, &clockevents_released, list) |
591 | list_del(&dev->list); | |
592 | /* | |
593 | * Now check whether the CPU has left unused per cpu devices | |
594 | */ | |
595 | cpu = *((int *)arg); | |
596 | list_for_each_entry_safe(dev, tmp, &clockevent_devices, list) { | |
597 | if (cpumask_test_cpu(cpu, dev->cpumask) && | |
ea9d8e3f XF |
598 | cpumask_weight(dev->cpumask) == 1 && |
599 | !tick_is_broadcast_device(dev)) { | |
bb6eddf7 TG |
600 | BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); |
601 | list_del(&dev->list); | |
602 | } | |
603 | } | |
d316c57f TG |
604 | break; |
605 | default: | |
606 | break; | |
607 | } | |
b5f91da0 | 608 | raw_spin_unlock_irqrestore(&clockevents_lock, flags); |
da7e6f45 | 609 | return ret; |
d316c57f TG |
610 | } |
611 | EXPORT_SYMBOL_GPL(clockevents_notify); | |
501f8670 TG |
612 | |
613 | #ifdef CONFIG_SYSFS | |
614 | struct bus_type clockevents_subsys = { | |
615 | .name = "clockevents", | |
616 | .dev_name = "clockevent", | |
617 | }; | |
618 | ||
619 | static DEFINE_PER_CPU(struct device, tick_percpu_dev); | |
620 | static struct tick_device *tick_get_tick_dev(struct device *dev); | |
621 | ||
622 | static ssize_t sysfs_show_current_tick_dev(struct device *dev, | |
623 | struct device_attribute *attr, | |
624 | char *buf) | |
625 | { | |
626 | struct tick_device *td; | |
627 | ssize_t count = 0; | |
628 | ||
629 | raw_spin_lock_irq(&clockevents_lock); | |
630 | td = tick_get_tick_dev(dev); | |
631 | if (td && td->evtdev) | |
632 | count = snprintf(buf, PAGE_SIZE, "%s\n", td->evtdev->name); | |
633 | raw_spin_unlock_irq(&clockevents_lock); | |
634 | return count; | |
635 | } | |
636 | static DEVICE_ATTR(current_device, 0444, sysfs_show_current_tick_dev, NULL); | |
637 | ||
03e13cf5 TG |
638 | /* We don't support the abomination of removable broadcast devices */ |
639 | static ssize_t sysfs_unbind_tick_dev(struct device *dev, | |
640 | struct device_attribute *attr, | |
641 | const char *buf, size_t count) | |
642 | { | |
643 | char name[CS_NAME_LEN]; | |
891292a7 | 644 | ssize_t ret = sysfs_get_uname(buf, name, count); |
03e13cf5 TG |
645 | struct clock_event_device *ce; |
646 | ||
647 | if (ret < 0) | |
648 | return ret; | |
649 | ||
650 | ret = -ENODEV; | |
651 | mutex_lock(&clockevents_mutex); | |
652 | raw_spin_lock_irq(&clockevents_lock); | |
653 | list_for_each_entry(ce, &clockevent_devices, list) { | |
654 | if (!strcmp(ce->name, name)) { | |
655 | ret = __clockevents_try_unbind(ce, dev->id); | |
656 | break; | |
657 | } | |
658 | } | |
659 | raw_spin_unlock_irq(&clockevents_lock); | |
660 | /* | |
661 | * We hold clockevents_mutex, so ce can't go away | |
662 | */ | |
663 | if (ret == -EAGAIN) | |
664 | ret = clockevents_unbind(ce, dev->id); | |
665 | mutex_unlock(&clockevents_mutex); | |
666 | return ret ? ret : count; | |
667 | } | |
668 | static DEVICE_ATTR(unbind_device, 0200, NULL, sysfs_unbind_tick_dev); | |
669 | ||
501f8670 TG |
670 | #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST |
671 | static struct device tick_bc_dev = { | |
672 | .init_name = "broadcast", | |
673 | .id = 0, | |
674 | .bus = &clockevents_subsys, | |
675 | }; | |
676 | ||
677 | static struct tick_device *tick_get_tick_dev(struct device *dev) | |
678 | { | |
679 | return dev == &tick_bc_dev ? tick_get_broadcast_device() : | |
680 | &per_cpu(tick_cpu_device, dev->id); | |
681 | } | |
682 | ||
683 | static __init int tick_broadcast_init_sysfs(void) | |
684 | { | |
685 | int err = device_register(&tick_bc_dev); | |
686 | ||
687 | if (!err) | |
688 | err = device_create_file(&tick_bc_dev, &dev_attr_current_device); | |
689 | return err; | |
690 | } | |
691 | #else | |
692 | static struct tick_device *tick_get_tick_dev(struct device *dev) | |
693 | { | |
694 | return &per_cpu(tick_cpu_device, dev->id); | |
695 | } | |
696 | static inline int tick_broadcast_init_sysfs(void) { return 0; } | |
de68d9b1 | 697 | #endif |
501f8670 TG |
698 | |
699 | static int __init tick_init_sysfs(void) | |
700 | { | |
701 | int cpu; | |
702 | ||
703 | for_each_possible_cpu(cpu) { | |
704 | struct device *dev = &per_cpu(tick_percpu_dev, cpu); | |
705 | int err; | |
706 | ||
707 | dev->id = cpu; | |
708 | dev->bus = &clockevents_subsys; | |
709 | err = device_register(dev); | |
710 | if (!err) | |
711 | err = device_create_file(dev, &dev_attr_current_device); | |
03e13cf5 TG |
712 | if (!err) |
713 | err = device_create_file(dev, &dev_attr_unbind_device); | |
501f8670 TG |
714 | if (err) |
715 | return err; | |
716 | } | |
717 | return tick_broadcast_init_sysfs(); | |
718 | } | |
719 | ||
720 | static int __init clockevents_init_sysfs(void) | |
721 | { | |
722 | int err = subsys_system_register(&clockevents_subsys, NULL); | |
723 | ||
724 | if (!err) | |
725 | err = tick_init_sysfs(); | |
726 | return err; | |
727 | } | |
728 | device_initcall(clockevents_init_sysfs); | |
729 | #endif /* SYSFS */ | |
730 | ||
731 | #endif /* GENERIC_CLOCK_EVENTS */ |