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