1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Timers abstract layer
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7 #include <linux/delay.h>
8 #include <linux/init.h>
9 #include <linux/slab.h>
10 #include <linux/time.h>
11 #include <linux/mutex.h>
12 #include <linux/device.h>
13 #include <linux/module.h>
14 #include <linux/string.h>
15 #include <linux/sched/signal.h>
16 #include <sound/core.h>
17 #include <sound/timer.h>
18 #include <sound/control.h>
19 #include <sound/info.h>
20 #include <sound/minors.h>
21 #include <sound/initval.h>
22 #include <linux/kmod.h>
23
24 /* internal flags */
25 #define SNDRV_TIMER_IFLG_PAUSED 0x00010000
26 #define SNDRV_TIMER_IFLG_DEAD 0x00020000
27
28 #if IS_ENABLED(CONFIG_SND_HRTIMER)
29 #define DEFAULT_TIMER_LIMIT 4
30 #else
31 #define DEFAULT_TIMER_LIMIT 1
32 #endif
33
34 static int timer_limit = DEFAULT_TIMER_LIMIT;
35 static int timer_tstamp_monotonic = 1;
36 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
37 MODULE_DESCRIPTION("ALSA timer interface");
38 MODULE_LICENSE("GPL");
39 module_param(timer_limit, int, 0444);
40 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
41 module_param(timer_tstamp_monotonic, int, 0444);
42 MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
43
44 MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
45 MODULE_ALIAS("devname:snd/timer");
46
47 enum timer_tread_format {
48 TREAD_FORMAT_NONE = 0,
49 TREAD_FORMAT_TIME64,
50 TREAD_FORMAT_TIME32,
51 };
52
53 struct snd_timer_tread32 {
54 int event;
55 s32 tstamp_sec;
56 s32 tstamp_nsec;
57 unsigned int val;
58 };
59
60 struct snd_timer_tread64 {
61 int event;
62 u8 pad1[4];
63 s64 tstamp_sec;
64 s64 tstamp_nsec;
65 unsigned int val;
66 u8 pad2[4];
67 };
68
69 struct snd_timer_user {
70 struct snd_timer_instance *timeri;
71 int tread; /* enhanced read with timestamps and events */
72 unsigned long ticks;
73 unsigned long overrun;
74 int qhead;
75 int qtail;
76 int qused;
77 int queue_size;
78 bool disconnected;
79 struct snd_timer_read *queue;
80 struct snd_timer_tread64 *tqueue;
81 spinlock_t qlock;
82 unsigned long last_resolution;
83 unsigned int filter;
84 struct timespec64 tstamp; /* trigger tstamp */
85 wait_queue_head_t qchange_sleep;
86 struct snd_fasync *fasync;
87 struct mutex ioctl_lock;
88 };
89
90 struct snd_timer_status32 {
91 s32 tstamp_sec; /* Timestamp - last update */
92 s32 tstamp_nsec;
93 unsigned int resolution; /* current period resolution in ns */
94 unsigned int lost; /* counter of master tick lost */
95 unsigned int overrun; /* count of read queue overruns */
96 unsigned int queue; /* used queue size */
97 unsigned char reserved[64]; /* reserved */
98 };
99
100 #define SNDRV_TIMER_IOCTL_STATUS32 _IOR('T', 0x14, struct snd_timer_status32)
101
102 struct snd_timer_status64 {
103 s64 tstamp_sec; /* Timestamp - last update */
104 s64 tstamp_nsec;
105 unsigned int resolution; /* current period resolution in ns */
106 unsigned int lost; /* counter of master tick lost */
107 unsigned int overrun; /* count of read queue overruns */
108 unsigned int queue; /* used queue size */
109 unsigned char reserved[64]; /* reserved */
110 };
111
112 #define SNDRV_TIMER_IOCTL_STATUS64 _IOR('T', 0x14, struct snd_timer_status64)
113
114 /* list of timers */
115 static LIST_HEAD(snd_timer_list);
116
117 /* list of slave instances */
118 static LIST_HEAD(snd_timer_slave_list);
119
120 /* lock for slave active lists */
121 static DEFINE_SPINLOCK(slave_active_lock);
122
123 #define MAX_SLAVE_INSTANCES 1000
124 static int num_slaves;
125
126 static DEFINE_MUTEX(register_mutex);
127
128 static int snd_timer_free(struct snd_timer *timer);
129 static int snd_timer_dev_free(struct snd_device *device);
130 static int snd_timer_dev_register(struct snd_device *device);
131 static int snd_timer_dev_disconnect(struct snd_device *device);
132
133 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
134
135 /*
136 * create a timer instance with the given owner string.
137 */
snd_timer_instance_new(const char * owner)138 struct snd_timer_instance *snd_timer_instance_new(const char *owner)
139 {
140 struct snd_timer_instance *timeri;
141
142 timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
143 if (timeri == NULL)
144 return NULL;
145 timeri->owner = kstrdup(owner, GFP_KERNEL);
146 if (! timeri->owner) {
147 kfree(timeri);
148 return NULL;
149 }
150 INIT_LIST_HEAD(&timeri->open_list);
151 INIT_LIST_HEAD(&timeri->active_list);
152 INIT_LIST_HEAD(&timeri->ack_list);
153 INIT_LIST_HEAD(&timeri->slave_list_head);
154 INIT_LIST_HEAD(&timeri->slave_active_head);
155
156 return timeri;
157 }
158 EXPORT_SYMBOL(snd_timer_instance_new);
159
snd_timer_instance_free(struct snd_timer_instance * timeri)160 void snd_timer_instance_free(struct snd_timer_instance *timeri)
161 {
162 if (timeri) {
163 if (timeri->private_free)
164 timeri->private_free(timeri);
165 kfree(timeri->owner);
166 kfree(timeri);
167 }
168 }
169 EXPORT_SYMBOL(snd_timer_instance_free);
170
171 /*
172 * find a timer instance from the given timer id
173 */
snd_timer_find(struct snd_timer_id * tid)174 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
175 {
176 struct snd_timer *timer;
177
178 list_for_each_entry(timer, &snd_timer_list, device_list) {
179 if (timer->tmr_class != tid->dev_class)
180 continue;
181 if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
182 timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
183 (timer->card == NULL ||
184 timer->card->number != tid->card))
185 continue;
186 if (timer->tmr_device != tid->device)
187 continue;
188 if (timer->tmr_subdevice != tid->subdevice)
189 continue;
190 return timer;
191 }
192 return NULL;
193 }
194
195 #ifdef CONFIG_MODULES
196
snd_timer_request(struct snd_timer_id * tid)197 static void snd_timer_request(struct snd_timer_id *tid)
198 {
199 switch (tid->dev_class) {
200 case SNDRV_TIMER_CLASS_GLOBAL:
201 if (tid->device < timer_limit)
202 request_module("snd-timer-%i", tid->device);
203 break;
204 case SNDRV_TIMER_CLASS_CARD:
205 case SNDRV_TIMER_CLASS_PCM:
206 if (tid->card < snd_ecards_limit)
207 request_module("snd-card-%i", tid->card);
208 break;
209 default:
210 break;
211 }
212 }
213
214 #endif
215
216 /* move the slave if it belongs to the master; return 1 if match */
check_matching_master_slave(struct snd_timer_instance * master,struct snd_timer_instance * slave)217 static int check_matching_master_slave(struct snd_timer_instance *master,
218 struct snd_timer_instance *slave)
219 {
220 if (slave->slave_class != master->slave_class ||
221 slave->slave_id != master->slave_id)
222 return 0;
223 if (master->timer->num_instances >= master->timer->max_instances)
224 return -EBUSY;
225 list_move_tail(&slave->open_list, &master->slave_list_head);
226 master->timer->num_instances++;
227 spin_lock_irq(&slave_active_lock);
228 spin_lock(&master->timer->lock);
229 slave->master = master;
230 slave->timer = master->timer;
231 if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
232 list_add_tail(&slave->active_list, &master->slave_active_head);
233 spin_unlock(&master->timer->lock);
234 spin_unlock_irq(&slave_active_lock);
235 return 1;
236 }
237
238 /*
239 * look for a master instance matching with the slave id of the given slave.
240 * when found, relink the open_link of the slave.
241 *
242 * call this with register_mutex down.
243 */
snd_timer_check_slave(struct snd_timer_instance * slave)244 static int snd_timer_check_slave(struct snd_timer_instance *slave)
245 {
246 struct snd_timer *timer;
247 struct snd_timer_instance *master;
248 int err = 0;
249
250 /* FIXME: it's really dumb to look up all entries.. */
251 list_for_each_entry(timer, &snd_timer_list, device_list) {
252 list_for_each_entry(master, &timer->open_list_head, open_list) {
253 err = check_matching_master_slave(master, slave);
254 if (err != 0) /* match found or error */
255 goto out;
256 }
257 }
258 out:
259 return err < 0 ? err : 0;
260 }
261
262 /*
263 * look for slave instances matching with the slave id of the given master.
264 * when found, relink the open_link of slaves.
265 *
266 * call this with register_mutex down.
267 */
snd_timer_check_master(struct snd_timer_instance * master)268 static int snd_timer_check_master(struct snd_timer_instance *master)
269 {
270 struct snd_timer_instance *slave, *tmp;
271 int err = 0;
272
273 /* check all pending slaves */
274 list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
275 err = check_matching_master_slave(master, slave);
276 if (err < 0)
277 break;
278 }
279 return err < 0 ? err : 0;
280 }
281
282 static void snd_timer_close_locked(struct snd_timer_instance *timeri,
283 struct device **card_devp_to_put);
284
285 /*
286 * open a timer instance
287 * when opening a master, the slave id must be here given.
288 */
snd_timer_open(struct snd_timer_instance * timeri,struct snd_timer_id * tid,unsigned int slave_id)289 int snd_timer_open(struct snd_timer_instance *timeri,
290 struct snd_timer_id *tid,
291 unsigned int slave_id)
292 {
293 struct snd_timer *timer;
294 struct device *card_dev_to_put = NULL;
295 int err;
296
297 mutex_lock(®ister_mutex);
298 if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
299 /* open a slave instance */
300 if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
301 tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
302 pr_debug("ALSA: timer: invalid slave class %i\n",
303 tid->dev_sclass);
304 err = -EINVAL;
305 goto unlock;
306 }
307 if (num_slaves >= MAX_SLAVE_INSTANCES) {
308 err = -EBUSY;
309 goto unlock;
310 }
311 timeri->slave_class = tid->dev_sclass;
312 timeri->slave_id = tid->device;
313 timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
314 list_add_tail(&timeri->open_list, &snd_timer_slave_list);
315 num_slaves++;
316 err = snd_timer_check_slave(timeri);
317 goto list_added;
318 }
319
320 /* open a master instance */
321 timer = snd_timer_find(tid);
322 #ifdef CONFIG_MODULES
323 if (!timer) {
324 mutex_unlock(®ister_mutex);
325 snd_timer_request(tid);
326 mutex_lock(®ister_mutex);
327 timer = snd_timer_find(tid);
328 }
329 #endif
330 if (!timer) {
331 err = -ENODEV;
332 goto unlock;
333 }
334 if (!list_empty(&timer->open_list_head)) {
335 struct snd_timer_instance *t =
336 list_entry(timer->open_list_head.next,
337 struct snd_timer_instance, open_list);
338 if (t->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
339 err = -EBUSY;
340 goto unlock;
341 }
342 }
343 if (timer->num_instances >= timer->max_instances) {
344 err = -EBUSY;
345 goto unlock;
346 }
347 if (!try_module_get(timer->module)) {
348 err = -EBUSY;
349 goto unlock;
350 }
351 /* take a card refcount for safe disconnection */
352 if (timer->card) {
353 get_device(&timer->card->card_dev);
354 card_dev_to_put = &timer->card->card_dev;
355 }
356
357 if (list_empty(&timer->open_list_head) && timer->hw.open) {
358 err = timer->hw.open(timer);
359 if (err) {
360 module_put(timer->module);
361 goto unlock;
362 }
363 }
364
365 timeri->timer = timer;
366 timeri->slave_class = tid->dev_sclass;
367 timeri->slave_id = slave_id;
368
369 list_add_tail(&timeri->open_list, &timer->open_list_head);
370 timer->num_instances++;
371 err = snd_timer_check_master(timeri);
372 list_added:
373 if (err < 0)
374 snd_timer_close_locked(timeri, &card_dev_to_put);
375
376 unlock:
377 mutex_unlock(®ister_mutex);
378 /* put_device() is called after unlock for avoiding deadlock */
379 if (err < 0 && card_dev_to_put)
380 put_device(card_dev_to_put);
381 return err;
382 }
383 EXPORT_SYMBOL(snd_timer_open);
384
385 /*
386 * close a timer instance
387 * call this with register_mutex down.
388 */
snd_timer_close_locked(struct snd_timer_instance * timeri,struct device ** card_devp_to_put)389 static void snd_timer_close_locked(struct snd_timer_instance *timeri,
390 struct device **card_devp_to_put)
391 {
392 struct snd_timer *timer = timeri->timer;
393 struct snd_timer_instance *slave, *tmp;
394
395 if (timer) {
396 spin_lock_irq(&timer->lock);
397 timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
398 spin_unlock_irq(&timer->lock);
399 }
400
401 if (!list_empty(&timeri->open_list)) {
402 list_del_init(&timeri->open_list);
403 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
404 num_slaves--;
405 }
406
407 /* force to stop the timer */
408 snd_timer_stop(timeri);
409
410 if (timer) {
411 timer->num_instances--;
412 /* wait, until the active callback is finished */
413 spin_lock_irq(&timer->lock);
414 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
415 spin_unlock_irq(&timer->lock);
416 udelay(10);
417 spin_lock_irq(&timer->lock);
418 }
419 spin_unlock_irq(&timer->lock);
420
421 /* remove slave links */
422 spin_lock_irq(&slave_active_lock);
423 spin_lock(&timer->lock);
424 timeri->timer = NULL;
425 list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
426 open_list) {
427 list_move_tail(&slave->open_list, &snd_timer_slave_list);
428 timer->num_instances--;
429 slave->master = NULL;
430 slave->timer = NULL;
431 list_del_init(&slave->ack_list);
432 list_del_init(&slave->active_list);
433 }
434 spin_unlock(&timer->lock);
435 spin_unlock_irq(&slave_active_lock);
436
437 /* slave doesn't need to release timer resources below */
438 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
439 timer = NULL;
440 }
441
442 if (timer) {
443 if (list_empty(&timer->open_list_head) && timer->hw.close)
444 timer->hw.close(timer);
445 /* release a card refcount for safe disconnection */
446 if (timer->card)
447 *card_devp_to_put = &timer->card->card_dev;
448 module_put(timer->module);
449 }
450 }
451
452 /*
453 * close a timer instance
454 */
snd_timer_close(struct snd_timer_instance * timeri)455 void snd_timer_close(struct snd_timer_instance *timeri)
456 {
457 struct device *card_dev_to_put = NULL;
458
459 if (snd_BUG_ON(!timeri))
460 return;
461
462 mutex_lock(®ister_mutex);
463 snd_timer_close_locked(timeri, &card_dev_to_put);
464 mutex_unlock(®ister_mutex);
465 /* put_device() is called after unlock for avoiding deadlock */
466 if (card_dev_to_put)
467 put_device(card_dev_to_put);
468 }
469 EXPORT_SYMBOL(snd_timer_close);
470
snd_timer_hw_resolution(struct snd_timer * timer)471 static unsigned long snd_timer_hw_resolution(struct snd_timer *timer)
472 {
473 if (timer->hw.c_resolution)
474 return timer->hw.c_resolution(timer);
475 else
476 return timer->hw.resolution;
477 }
478
snd_timer_resolution(struct snd_timer_instance * timeri)479 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
480 {
481 struct snd_timer * timer;
482 unsigned long ret = 0;
483 unsigned long flags;
484
485 if (timeri == NULL)
486 return 0;
487 timer = timeri->timer;
488 if (timer) {
489 spin_lock_irqsave(&timer->lock, flags);
490 ret = snd_timer_hw_resolution(timer);
491 spin_unlock_irqrestore(&timer->lock, flags);
492 }
493 return ret;
494 }
495 EXPORT_SYMBOL(snd_timer_resolution);
496
snd_timer_notify1(struct snd_timer_instance * ti,int event)497 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
498 {
499 struct snd_timer *timer = ti->timer;
500 unsigned long resolution = 0;
501 struct snd_timer_instance *ts;
502 struct timespec64 tstamp;
503
504 if (timer_tstamp_monotonic)
505 ktime_get_ts64(&tstamp);
506 else
507 ktime_get_real_ts64(&tstamp);
508 if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
509 event > SNDRV_TIMER_EVENT_PAUSE))
510 return;
511 if (timer &&
512 (event == SNDRV_TIMER_EVENT_START ||
513 event == SNDRV_TIMER_EVENT_CONTINUE))
514 resolution = snd_timer_hw_resolution(timer);
515 if (ti->ccallback)
516 ti->ccallback(ti, event, &tstamp, resolution);
517 if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
518 return;
519 if (timer == NULL)
520 return;
521 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
522 return;
523 event += 10; /* convert to SNDRV_TIMER_EVENT_MXXX */
524 list_for_each_entry(ts, &ti->slave_active_head, active_list)
525 if (ts->ccallback)
526 ts->ccallback(ts, event, &tstamp, resolution);
527 }
528
529 /* start/continue a master timer */
snd_timer_start1(struct snd_timer_instance * timeri,bool start,unsigned long ticks)530 static int snd_timer_start1(struct snd_timer_instance *timeri,
531 bool start, unsigned long ticks)
532 {
533 struct snd_timer *timer;
534 int result;
535 unsigned long flags;
536
537 timer = timeri->timer;
538 if (!timer)
539 return -EINVAL;
540
541 spin_lock_irqsave(&timer->lock, flags);
542 if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
543 result = -EINVAL;
544 goto unlock;
545 }
546 if (timer->card && timer->card->shutdown) {
547 result = -ENODEV;
548 goto unlock;
549 }
550 if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
551 SNDRV_TIMER_IFLG_START)) {
552 result = -EBUSY;
553 goto unlock;
554 }
555
556 /* check the actual time for the start tick;
557 * bail out as error if it's way too low (< 100us)
558 */
559 if (start) {
560 if ((u64)snd_timer_hw_resolution(timer) * ticks < 100000) {
561 result = -EINVAL;
562 goto unlock;
563 }
564 }
565
566 if (start)
567 timeri->ticks = timeri->cticks = ticks;
568 else if (!timeri->cticks)
569 timeri->cticks = 1;
570 timeri->pticks = 0;
571
572 list_move_tail(&timeri->active_list, &timer->active_list_head);
573 if (timer->running) {
574 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
575 goto __start_now;
576 timer->flags |= SNDRV_TIMER_FLG_RESCHED;
577 timeri->flags |= SNDRV_TIMER_IFLG_START;
578 result = 1; /* delayed start */
579 } else {
580 if (start)
581 timer->sticks = ticks;
582 timer->hw.start(timer);
583 __start_now:
584 timer->running++;
585 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
586 result = 0;
587 }
588 snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
589 SNDRV_TIMER_EVENT_CONTINUE);
590 unlock:
591 spin_unlock_irqrestore(&timer->lock, flags);
592 return result;
593 }
594
595 /* start/continue a slave timer */
snd_timer_start_slave(struct snd_timer_instance * timeri,bool start)596 static int snd_timer_start_slave(struct snd_timer_instance *timeri,
597 bool start)
598 {
599 unsigned long flags;
600 int err;
601
602 spin_lock_irqsave(&slave_active_lock, flags);
603 if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
604 err = -EINVAL;
605 goto unlock;
606 }
607 if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
608 err = -EBUSY;
609 goto unlock;
610 }
611 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
612 if (timeri->master && timeri->timer) {
613 spin_lock(&timeri->timer->lock);
614 list_add_tail(&timeri->active_list,
615 &timeri->master->slave_active_head);
616 snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
617 SNDRV_TIMER_EVENT_CONTINUE);
618 spin_unlock(&timeri->timer->lock);
619 }
620 err = 1; /* delayed start */
621 unlock:
622 spin_unlock_irqrestore(&slave_active_lock, flags);
623 return err;
624 }
625
626 /* stop/pause a master timer */
snd_timer_stop1(struct snd_timer_instance * timeri,bool stop)627 static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
628 {
629 struct snd_timer *timer;
630 int result = 0;
631 unsigned long flags;
632
633 timer = timeri->timer;
634 if (!timer)
635 return -EINVAL;
636 spin_lock_irqsave(&timer->lock, flags);
637 list_del_init(&timeri->ack_list);
638 list_del_init(&timeri->active_list);
639 if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
640 SNDRV_TIMER_IFLG_START))) {
641 result = -EBUSY;
642 goto unlock;
643 }
644 if (timer->card && timer->card->shutdown)
645 goto unlock;
646 if (stop) {
647 timeri->cticks = timeri->ticks;
648 timeri->pticks = 0;
649 }
650 if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
651 !(--timer->running)) {
652 timer->hw.stop(timer);
653 if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
654 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
655 snd_timer_reschedule(timer, 0);
656 if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
657 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
658 timer->hw.start(timer);
659 }
660 }
661 }
662 timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
663 if (stop)
664 timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
665 else
666 timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
667 snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
668 SNDRV_TIMER_EVENT_PAUSE);
669 unlock:
670 spin_unlock_irqrestore(&timer->lock, flags);
671 return result;
672 }
673
674 /* stop/pause a slave timer */
snd_timer_stop_slave(struct snd_timer_instance * timeri,bool stop)675 static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
676 {
677 unsigned long flags;
678 bool running;
679
680 spin_lock_irqsave(&slave_active_lock, flags);
681 running = timeri->flags & SNDRV_TIMER_IFLG_RUNNING;
682 timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
683 if (timeri->timer) {
684 spin_lock(&timeri->timer->lock);
685 list_del_init(&timeri->ack_list);
686 list_del_init(&timeri->active_list);
687 if (running)
688 snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
689 SNDRV_TIMER_EVENT_PAUSE);
690 spin_unlock(&timeri->timer->lock);
691 }
692 spin_unlock_irqrestore(&slave_active_lock, flags);
693 return running ? 0 : -EBUSY;
694 }
695
696 /*
697 * start the timer instance
698 */
snd_timer_start(struct snd_timer_instance * timeri,unsigned int ticks)699 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
700 {
701 if (timeri == NULL || ticks < 1)
702 return -EINVAL;
703 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
704 return snd_timer_start_slave(timeri, true);
705 else
706 return snd_timer_start1(timeri, true, ticks);
707 }
708 EXPORT_SYMBOL(snd_timer_start);
709
710 /*
711 * stop the timer instance.
712 *
713 * do not call this from the timer callback!
714 */
snd_timer_stop(struct snd_timer_instance * timeri)715 int snd_timer_stop(struct snd_timer_instance *timeri)
716 {
717 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
718 return snd_timer_stop_slave(timeri, true);
719 else
720 return snd_timer_stop1(timeri, true);
721 }
722 EXPORT_SYMBOL(snd_timer_stop);
723
724 /*
725 * start again.. the tick is kept.
726 */
snd_timer_continue(struct snd_timer_instance * timeri)727 int snd_timer_continue(struct snd_timer_instance *timeri)
728 {
729 /* timer can continue only after pause */
730 if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
731 return -EINVAL;
732
733 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
734 return snd_timer_start_slave(timeri, false);
735 else
736 return snd_timer_start1(timeri, false, 0);
737 }
738 EXPORT_SYMBOL(snd_timer_continue);
739
740 /*
741 * pause.. remember the ticks left
742 */
snd_timer_pause(struct snd_timer_instance * timeri)743 int snd_timer_pause(struct snd_timer_instance * timeri)
744 {
745 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
746 return snd_timer_stop_slave(timeri, false);
747 else
748 return snd_timer_stop1(timeri, false);
749 }
750 EXPORT_SYMBOL(snd_timer_pause);
751
752 /*
753 * reschedule the timer
754 *
755 * start pending instances and check the scheduling ticks.
756 * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
757 */
snd_timer_reschedule(struct snd_timer * timer,unsigned long ticks_left)758 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
759 {
760 struct snd_timer_instance *ti;
761 unsigned long ticks = ~0UL;
762
763 list_for_each_entry(ti, &timer->active_list_head, active_list) {
764 if (ti->flags & SNDRV_TIMER_IFLG_START) {
765 ti->flags &= ~SNDRV_TIMER_IFLG_START;
766 ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
767 timer->running++;
768 }
769 if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
770 if (ticks > ti->cticks)
771 ticks = ti->cticks;
772 }
773 }
774 if (ticks == ~0UL) {
775 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
776 return;
777 }
778 if (ticks > timer->hw.ticks)
779 ticks = timer->hw.ticks;
780 if (ticks_left != ticks)
781 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
782 timer->sticks = ticks;
783 }
784
785 /* call callbacks in timer ack list */
snd_timer_process_callbacks(struct snd_timer * timer,struct list_head * head)786 static void snd_timer_process_callbacks(struct snd_timer *timer,
787 struct list_head *head)
788 {
789 struct snd_timer_instance *ti;
790 unsigned long resolution, ticks;
791
792 while (!list_empty(head)) {
793 ti = list_first_entry(head, struct snd_timer_instance,
794 ack_list);
795
796 /* remove from ack_list and make empty */
797 list_del_init(&ti->ack_list);
798
799 if (!(ti->flags & SNDRV_TIMER_IFLG_DEAD)) {
800 ticks = ti->pticks;
801 ti->pticks = 0;
802 resolution = ti->resolution;
803 ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
804 spin_unlock(&timer->lock);
805 if (ti->callback)
806 ti->callback(ti, resolution, ticks);
807 spin_lock(&timer->lock);
808 ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
809 }
810 }
811 }
812
813 /* clear pending instances from ack list */
snd_timer_clear_callbacks(struct snd_timer * timer,struct list_head * head)814 static void snd_timer_clear_callbacks(struct snd_timer *timer,
815 struct list_head *head)
816 {
817 unsigned long flags;
818
819 spin_lock_irqsave(&timer->lock, flags);
820 while (!list_empty(head))
821 list_del_init(head->next);
822 spin_unlock_irqrestore(&timer->lock, flags);
823 }
824
825 /*
826 * timer work
827 *
828 */
snd_timer_work(struct work_struct * work)829 static void snd_timer_work(struct work_struct *work)
830 {
831 struct snd_timer *timer = container_of(work, struct snd_timer, task_work);
832 unsigned long flags;
833
834 if (timer->card && timer->card->shutdown) {
835 snd_timer_clear_callbacks(timer, &timer->sack_list_head);
836 return;
837 }
838
839 spin_lock_irqsave(&timer->lock, flags);
840 snd_timer_process_callbacks(timer, &timer->sack_list_head);
841 spin_unlock_irqrestore(&timer->lock, flags);
842 }
843
844 /*
845 * timer interrupt
846 *
847 * ticks_left is usually equal to timer->sticks.
848 *
849 */
snd_timer_interrupt(struct snd_timer * timer,unsigned long ticks_left)850 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
851 {
852 struct snd_timer_instance *ti, *ts, *tmp;
853 unsigned long resolution;
854 struct list_head *ack_list_head;
855 unsigned long flags;
856 bool use_work = false;
857
858 if (timer == NULL)
859 return;
860
861 if (timer->card && timer->card->shutdown) {
862 snd_timer_clear_callbacks(timer, &timer->ack_list_head);
863 return;
864 }
865
866 spin_lock_irqsave(&timer->lock, flags);
867
868 /* remember the current resolution */
869 resolution = snd_timer_hw_resolution(timer);
870
871 /* loop for all active instances
872 * Here we cannot use list_for_each_entry because the active_list of a
873 * processed instance is relinked to done_list_head before the callback
874 * is called.
875 */
876 list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
877 active_list) {
878 if (ti->flags & SNDRV_TIMER_IFLG_DEAD)
879 continue;
880 if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
881 continue;
882 ti->pticks += ticks_left;
883 ti->resolution = resolution;
884 if (ti->cticks < ticks_left)
885 ti->cticks = 0;
886 else
887 ti->cticks -= ticks_left;
888 if (ti->cticks) /* not expired */
889 continue;
890 if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
891 ti->cticks = ti->ticks;
892 } else {
893 ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
894 --timer->running;
895 list_del_init(&ti->active_list);
896 }
897 if ((timer->hw.flags & SNDRV_TIMER_HW_WORK) ||
898 (ti->flags & SNDRV_TIMER_IFLG_FAST))
899 ack_list_head = &timer->ack_list_head;
900 else
901 ack_list_head = &timer->sack_list_head;
902 if (list_empty(&ti->ack_list))
903 list_add_tail(&ti->ack_list, ack_list_head);
904 list_for_each_entry(ts, &ti->slave_active_head, active_list) {
905 ts->pticks = ti->pticks;
906 ts->resolution = resolution;
907 if (list_empty(&ts->ack_list))
908 list_add_tail(&ts->ack_list, ack_list_head);
909 }
910 }
911 if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
912 snd_timer_reschedule(timer, timer->sticks);
913 if (timer->running) {
914 if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
915 timer->hw.stop(timer);
916 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
917 }
918 if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
919 (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
920 /* restart timer */
921 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
922 timer->hw.start(timer);
923 }
924 } else {
925 timer->hw.stop(timer);
926 }
927
928 /* now process all fast callbacks */
929 snd_timer_process_callbacks(timer, &timer->ack_list_head);
930
931 /* do we have any slow callbacks? */
932 use_work = !list_empty(&timer->sack_list_head);
933 spin_unlock_irqrestore(&timer->lock, flags);
934
935 if (use_work)
936 queue_work(system_highpri_wq, &timer->task_work);
937 }
938 EXPORT_SYMBOL(snd_timer_interrupt);
939
940 /*
941
942 */
943
snd_timer_new(struct snd_card * card,char * id,struct snd_timer_id * tid,struct snd_timer ** rtimer)944 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
945 struct snd_timer **rtimer)
946 {
947 struct snd_timer *timer;
948 int err;
949 static const struct snd_device_ops ops = {
950 .dev_free = snd_timer_dev_free,
951 .dev_register = snd_timer_dev_register,
952 .dev_disconnect = snd_timer_dev_disconnect,
953 };
954
955 if (snd_BUG_ON(!tid))
956 return -EINVAL;
957 if (tid->dev_class == SNDRV_TIMER_CLASS_CARD ||
958 tid->dev_class == SNDRV_TIMER_CLASS_PCM) {
959 if (WARN_ON(!card))
960 return -EINVAL;
961 }
962 if (rtimer)
963 *rtimer = NULL;
964 timer = kzalloc(sizeof(*timer), GFP_KERNEL);
965 if (!timer)
966 return -ENOMEM;
967 timer->tmr_class = tid->dev_class;
968 timer->card = card;
969 timer->tmr_device = tid->device;
970 timer->tmr_subdevice = tid->subdevice;
971 if (id)
972 strscpy(timer->id, id, sizeof(timer->id));
973 timer->sticks = 1;
974 INIT_LIST_HEAD(&timer->device_list);
975 INIT_LIST_HEAD(&timer->open_list_head);
976 INIT_LIST_HEAD(&timer->active_list_head);
977 INIT_LIST_HEAD(&timer->ack_list_head);
978 INIT_LIST_HEAD(&timer->sack_list_head);
979 spin_lock_init(&timer->lock);
980 INIT_WORK(&timer->task_work, snd_timer_work);
981 timer->max_instances = 1000; /* default limit per timer */
982 if (card != NULL) {
983 timer->module = card->module;
984 err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
985 if (err < 0) {
986 snd_timer_free(timer);
987 return err;
988 }
989 }
990 if (rtimer)
991 *rtimer = timer;
992 return 0;
993 }
994 EXPORT_SYMBOL(snd_timer_new);
995
snd_timer_free(struct snd_timer * timer)996 static int snd_timer_free(struct snd_timer *timer)
997 {
998 if (!timer)
999 return 0;
1000
1001 mutex_lock(®ister_mutex);
1002 if (! list_empty(&timer->open_list_head)) {
1003 struct list_head *p, *n;
1004 struct snd_timer_instance *ti;
1005 pr_warn("ALSA: timer %p is busy?\n", timer);
1006 list_for_each_safe(p, n, &timer->open_list_head) {
1007 list_del_init(p);
1008 ti = list_entry(p, struct snd_timer_instance, open_list);
1009 ti->timer = NULL;
1010 }
1011 }
1012 list_del(&timer->device_list);
1013 mutex_unlock(®ister_mutex);
1014
1015 if (timer->private_free)
1016 timer->private_free(timer);
1017 kfree(timer);
1018 return 0;
1019 }
1020
snd_timer_dev_free(struct snd_device * device)1021 static int snd_timer_dev_free(struct snd_device *device)
1022 {
1023 struct snd_timer *timer = device->device_data;
1024 return snd_timer_free(timer);
1025 }
1026
snd_timer_dev_register(struct snd_device * dev)1027 static int snd_timer_dev_register(struct snd_device *dev)
1028 {
1029 struct snd_timer *timer = dev->device_data;
1030 struct snd_timer *timer1;
1031
1032 if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
1033 return -ENXIO;
1034 if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
1035 !timer->hw.resolution && timer->hw.c_resolution == NULL)
1036 return -EINVAL;
1037
1038 mutex_lock(®ister_mutex);
1039 list_for_each_entry(timer1, &snd_timer_list, device_list) {
1040 if (timer1->tmr_class > timer->tmr_class)
1041 break;
1042 if (timer1->tmr_class < timer->tmr_class)
1043 continue;
1044 if (timer1->card && timer->card) {
1045 if (timer1->card->number > timer->card->number)
1046 break;
1047 if (timer1->card->number < timer->card->number)
1048 continue;
1049 }
1050 if (timer1->tmr_device > timer->tmr_device)
1051 break;
1052 if (timer1->tmr_device < timer->tmr_device)
1053 continue;
1054 if (timer1->tmr_subdevice > timer->tmr_subdevice)
1055 break;
1056 if (timer1->tmr_subdevice < timer->tmr_subdevice)
1057 continue;
1058 /* conflicts.. */
1059 mutex_unlock(®ister_mutex);
1060 return -EBUSY;
1061 }
1062 list_add_tail(&timer->device_list, &timer1->device_list);
1063 mutex_unlock(®ister_mutex);
1064 return 0;
1065 }
1066
snd_timer_dev_disconnect(struct snd_device * device)1067 static int snd_timer_dev_disconnect(struct snd_device *device)
1068 {
1069 struct snd_timer *timer = device->device_data;
1070 struct snd_timer_instance *ti;
1071
1072 mutex_lock(®ister_mutex);
1073 list_del_init(&timer->device_list);
1074 /* wake up pending sleepers */
1075 list_for_each_entry(ti, &timer->open_list_head, open_list) {
1076 if (ti->disconnect)
1077 ti->disconnect(ti);
1078 }
1079 mutex_unlock(®ister_mutex);
1080 return 0;
1081 }
1082
snd_timer_notify(struct snd_timer * timer,int event,struct timespec64 * tstamp)1083 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp)
1084 {
1085 unsigned long flags;
1086 unsigned long resolution = 0;
1087 struct snd_timer_instance *ti, *ts;
1088
1089 if (timer->card && timer->card->shutdown)
1090 return;
1091 if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
1092 return;
1093 if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
1094 event > SNDRV_TIMER_EVENT_MRESUME))
1095 return;
1096 spin_lock_irqsave(&timer->lock, flags);
1097 if (event == SNDRV_TIMER_EVENT_MSTART ||
1098 event == SNDRV_TIMER_EVENT_MCONTINUE ||
1099 event == SNDRV_TIMER_EVENT_MRESUME)
1100 resolution = snd_timer_hw_resolution(timer);
1101 list_for_each_entry(ti, &timer->active_list_head, active_list) {
1102 if (ti->ccallback)
1103 ti->ccallback(ti, event, tstamp, resolution);
1104 list_for_each_entry(ts, &ti->slave_active_head, active_list)
1105 if (ts->ccallback)
1106 ts->ccallback(ts, event, tstamp, resolution);
1107 }
1108 spin_unlock_irqrestore(&timer->lock, flags);
1109 }
1110 EXPORT_SYMBOL(snd_timer_notify);
1111
1112 /*
1113 * exported functions for global timers
1114 */
snd_timer_global_new(char * id,int device,struct snd_timer ** rtimer)1115 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
1116 {
1117 struct snd_timer_id tid;
1118
1119 tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
1120 tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1121 tid.card = -1;
1122 tid.device = device;
1123 tid.subdevice = 0;
1124 return snd_timer_new(NULL, id, &tid, rtimer);
1125 }
1126 EXPORT_SYMBOL(snd_timer_global_new);
1127
snd_timer_global_free(struct snd_timer * timer)1128 int snd_timer_global_free(struct snd_timer *timer)
1129 {
1130 return snd_timer_free(timer);
1131 }
1132 EXPORT_SYMBOL(snd_timer_global_free);
1133
snd_timer_global_register(struct snd_timer * timer)1134 int snd_timer_global_register(struct snd_timer *timer)
1135 {
1136 struct snd_device dev;
1137
1138 memset(&dev, 0, sizeof(dev));
1139 dev.device_data = timer;
1140 return snd_timer_dev_register(&dev);
1141 }
1142 EXPORT_SYMBOL(snd_timer_global_register);
1143
1144 /*
1145 * System timer
1146 */
1147
1148 struct snd_timer_system_private {
1149 struct timer_list tlist;
1150 struct snd_timer *snd_timer;
1151 unsigned long last_expires;
1152 unsigned long last_jiffies;
1153 unsigned long correction;
1154 };
1155
snd_timer_s_function(struct timer_list * t)1156 static void snd_timer_s_function(struct timer_list *t)
1157 {
1158 struct snd_timer_system_private *priv = from_timer(priv, t,
1159 tlist);
1160 struct snd_timer *timer = priv->snd_timer;
1161 unsigned long jiff = jiffies;
1162 if (time_after(jiff, priv->last_expires))
1163 priv->correction += (long)jiff - (long)priv->last_expires;
1164 snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
1165 }
1166
snd_timer_s_start(struct snd_timer * timer)1167 static int snd_timer_s_start(struct snd_timer * timer)
1168 {
1169 struct snd_timer_system_private *priv;
1170 unsigned long njiff;
1171
1172 priv = (struct snd_timer_system_private *) timer->private_data;
1173 njiff = (priv->last_jiffies = jiffies);
1174 if (priv->correction > timer->sticks - 1) {
1175 priv->correction -= timer->sticks - 1;
1176 njiff++;
1177 } else {
1178 njiff += timer->sticks - priv->correction;
1179 priv->correction = 0;
1180 }
1181 priv->last_expires = njiff;
1182 mod_timer(&priv->tlist, njiff);
1183 return 0;
1184 }
1185
snd_timer_s_stop(struct snd_timer * timer)1186 static int snd_timer_s_stop(struct snd_timer * timer)
1187 {
1188 struct snd_timer_system_private *priv;
1189 unsigned long jiff;
1190
1191 priv = (struct snd_timer_system_private *) timer->private_data;
1192 del_timer(&priv->tlist);
1193 jiff = jiffies;
1194 if (time_before(jiff, priv->last_expires))
1195 timer->sticks = priv->last_expires - jiff;
1196 else
1197 timer->sticks = 1;
1198 priv->correction = 0;
1199 return 0;
1200 }
1201
snd_timer_s_close(struct snd_timer * timer)1202 static int snd_timer_s_close(struct snd_timer *timer)
1203 {
1204 struct snd_timer_system_private *priv;
1205
1206 priv = (struct snd_timer_system_private *)timer->private_data;
1207 del_timer_sync(&priv->tlist);
1208 return 0;
1209 }
1210
1211 static const struct snd_timer_hardware snd_timer_system =
1212 {
1213 .flags = SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_WORK,
1214 .resolution = 1000000000L / HZ,
1215 .ticks = 10000000L,
1216 .close = snd_timer_s_close,
1217 .start = snd_timer_s_start,
1218 .stop = snd_timer_s_stop
1219 };
1220
snd_timer_free_system(struct snd_timer * timer)1221 static void snd_timer_free_system(struct snd_timer *timer)
1222 {
1223 kfree(timer->private_data);
1224 }
1225
snd_timer_register_system(void)1226 static int snd_timer_register_system(void)
1227 {
1228 struct snd_timer *timer;
1229 struct snd_timer_system_private *priv;
1230 int err;
1231
1232 err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1233 if (err < 0)
1234 return err;
1235 strcpy(timer->name, "system timer");
1236 timer->hw = snd_timer_system;
1237 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1238 if (priv == NULL) {
1239 snd_timer_free(timer);
1240 return -ENOMEM;
1241 }
1242 priv->snd_timer = timer;
1243 timer_setup(&priv->tlist, snd_timer_s_function, 0);
1244 timer->private_data = priv;
1245 timer->private_free = snd_timer_free_system;
1246 return snd_timer_global_register(timer);
1247 }
1248
1249 #ifdef CONFIG_SND_PROC_FS
1250 /*
1251 * Info interface
1252 */
1253
snd_timer_proc_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)1254 static void snd_timer_proc_read(struct snd_info_entry *entry,
1255 struct snd_info_buffer *buffer)
1256 {
1257 struct snd_timer *timer;
1258 struct snd_timer_instance *ti;
1259 unsigned long resolution;
1260
1261 mutex_lock(®ister_mutex);
1262 list_for_each_entry(timer, &snd_timer_list, device_list) {
1263 if (timer->card && timer->card->shutdown)
1264 continue;
1265 switch (timer->tmr_class) {
1266 case SNDRV_TIMER_CLASS_GLOBAL:
1267 snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1268 break;
1269 case SNDRV_TIMER_CLASS_CARD:
1270 snd_iprintf(buffer, "C%i-%i: ",
1271 timer->card->number, timer->tmr_device);
1272 break;
1273 case SNDRV_TIMER_CLASS_PCM:
1274 snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1275 timer->tmr_device, timer->tmr_subdevice);
1276 break;
1277 default:
1278 snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1279 timer->card ? timer->card->number : -1,
1280 timer->tmr_device, timer->tmr_subdevice);
1281 }
1282 snd_iprintf(buffer, "%s :", timer->name);
1283 spin_lock_irq(&timer->lock);
1284 resolution = snd_timer_hw_resolution(timer);
1285 spin_unlock_irq(&timer->lock);
1286 if (resolution)
1287 snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1288 resolution / 1000,
1289 resolution % 1000,
1290 timer->hw.ticks);
1291 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1292 snd_iprintf(buffer, " SLAVE");
1293 snd_iprintf(buffer, "\n");
1294 list_for_each_entry(ti, &timer->open_list_head, open_list)
1295 snd_iprintf(buffer, " Client %s : %s\n",
1296 ti->owner ? ti->owner : "unknown",
1297 (ti->flags & (SNDRV_TIMER_IFLG_START |
1298 SNDRV_TIMER_IFLG_RUNNING))
1299 ? "running" : "stopped");
1300 }
1301 mutex_unlock(®ister_mutex);
1302 }
1303
1304 static struct snd_info_entry *snd_timer_proc_entry;
1305
snd_timer_proc_init(void)1306 static void __init snd_timer_proc_init(void)
1307 {
1308 struct snd_info_entry *entry;
1309
1310 entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1311 if (entry != NULL) {
1312 entry->c.text.read = snd_timer_proc_read;
1313 if (snd_info_register(entry) < 0) {
1314 snd_info_free_entry(entry);
1315 entry = NULL;
1316 }
1317 }
1318 snd_timer_proc_entry = entry;
1319 }
1320
snd_timer_proc_done(void)1321 static void __exit snd_timer_proc_done(void)
1322 {
1323 snd_info_free_entry(snd_timer_proc_entry);
1324 }
1325 #else /* !CONFIG_SND_PROC_FS */
1326 #define snd_timer_proc_init()
1327 #define snd_timer_proc_done()
1328 #endif
1329
1330 /*
1331 * USER SPACE interface
1332 */
1333
snd_timer_user_interrupt(struct snd_timer_instance * timeri,unsigned long resolution,unsigned long ticks)1334 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1335 unsigned long resolution,
1336 unsigned long ticks)
1337 {
1338 struct snd_timer_user *tu = timeri->callback_data;
1339 struct snd_timer_read *r;
1340 int prev;
1341
1342 spin_lock(&tu->qlock);
1343 if (tu->qused > 0) {
1344 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1345 r = &tu->queue[prev];
1346 if (r->resolution == resolution) {
1347 r->ticks += ticks;
1348 goto __wake;
1349 }
1350 }
1351 if (tu->qused >= tu->queue_size) {
1352 tu->overrun++;
1353 } else {
1354 r = &tu->queue[tu->qtail++];
1355 tu->qtail %= tu->queue_size;
1356 r->resolution = resolution;
1357 r->ticks = ticks;
1358 tu->qused++;
1359 }
1360 __wake:
1361 spin_unlock(&tu->qlock);
1362 snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1363 wake_up(&tu->qchange_sleep);
1364 }
1365
snd_timer_user_append_to_tqueue(struct snd_timer_user * tu,struct snd_timer_tread64 * tread)1366 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1367 struct snd_timer_tread64 *tread)
1368 {
1369 if (tu->qused >= tu->queue_size) {
1370 tu->overrun++;
1371 } else {
1372 memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1373 tu->qtail %= tu->queue_size;
1374 tu->qused++;
1375 }
1376 }
1377
snd_timer_user_ccallback(struct snd_timer_instance * timeri,int event,struct timespec64 * tstamp,unsigned long resolution)1378 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1379 int event,
1380 struct timespec64 *tstamp,
1381 unsigned long resolution)
1382 {
1383 struct snd_timer_user *tu = timeri->callback_data;
1384 struct snd_timer_tread64 r1;
1385 unsigned long flags;
1386
1387 if (event >= SNDRV_TIMER_EVENT_START &&
1388 event <= SNDRV_TIMER_EVENT_PAUSE)
1389 tu->tstamp = *tstamp;
1390 if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1391 return;
1392 memset(&r1, 0, sizeof(r1));
1393 r1.event = event;
1394 r1.tstamp_sec = tstamp->tv_sec;
1395 r1.tstamp_nsec = tstamp->tv_nsec;
1396 r1.val = resolution;
1397 spin_lock_irqsave(&tu->qlock, flags);
1398 snd_timer_user_append_to_tqueue(tu, &r1);
1399 spin_unlock_irqrestore(&tu->qlock, flags);
1400 snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1401 wake_up(&tu->qchange_sleep);
1402 }
1403
snd_timer_user_disconnect(struct snd_timer_instance * timeri)1404 static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1405 {
1406 struct snd_timer_user *tu = timeri->callback_data;
1407
1408 tu->disconnected = true;
1409 wake_up(&tu->qchange_sleep);
1410 }
1411
snd_timer_user_tinterrupt(struct snd_timer_instance * timeri,unsigned long resolution,unsigned long ticks)1412 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1413 unsigned long resolution,
1414 unsigned long ticks)
1415 {
1416 struct snd_timer_user *tu = timeri->callback_data;
1417 struct snd_timer_tread64 *r, r1;
1418 struct timespec64 tstamp;
1419 int prev, append = 0;
1420
1421 memset(&r1, 0, sizeof(r1));
1422 memset(&tstamp, 0, sizeof(tstamp));
1423 spin_lock(&tu->qlock);
1424 if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1425 (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1426 spin_unlock(&tu->qlock);
1427 return;
1428 }
1429 if (tu->last_resolution != resolution || ticks > 0) {
1430 if (timer_tstamp_monotonic)
1431 ktime_get_ts64(&tstamp);
1432 else
1433 ktime_get_real_ts64(&tstamp);
1434 }
1435 if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1436 tu->last_resolution != resolution) {
1437 r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1438 r1.tstamp_sec = tstamp.tv_sec;
1439 r1.tstamp_nsec = tstamp.tv_nsec;
1440 r1.val = resolution;
1441 snd_timer_user_append_to_tqueue(tu, &r1);
1442 tu->last_resolution = resolution;
1443 append++;
1444 }
1445 if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1446 goto __wake;
1447 if (ticks == 0)
1448 goto __wake;
1449 if (tu->qused > 0) {
1450 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1451 r = &tu->tqueue[prev];
1452 if (r->event == SNDRV_TIMER_EVENT_TICK) {
1453 r->tstamp_sec = tstamp.tv_sec;
1454 r->tstamp_nsec = tstamp.tv_nsec;
1455 r->val += ticks;
1456 append++;
1457 goto __wake;
1458 }
1459 }
1460 r1.event = SNDRV_TIMER_EVENT_TICK;
1461 r1.tstamp_sec = tstamp.tv_sec;
1462 r1.tstamp_nsec = tstamp.tv_nsec;
1463 r1.val = ticks;
1464 snd_timer_user_append_to_tqueue(tu, &r1);
1465 append++;
1466 __wake:
1467 spin_unlock(&tu->qlock);
1468 if (append == 0)
1469 return;
1470 snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1471 wake_up(&tu->qchange_sleep);
1472 }
1473
realloc_user_queue(struct snd_timer_user * tu,int size)1474 static int realloc_user_queue(struct snd_timer_user *tu, int size)
1475 {
1476 struct snd_timer_read *queue = NULL;
1477 struct snd_timer_tread64 *tqueue = NULL;
1478
1479 if (tu->tread) {
1480 tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
1481 if (!tqueue)
1482 return -ENOMEM;
1483 } else {
1484 queue = kcalloc(size, sizeof(*queue), GFP_KERNEL);
1485 if (!queue)
1486 return -ENOMEM;
1487 }
1488
1489 spin_lock_irq(&tu->qlock);
1490 kfree(tu->queue);
1491 kfree(tu->tqueue);
1492 tu->queue_size = size;
1493 tu->queue = queue;
1494 tu->tqueue = tqueue;
1495 tu->qhead = tu->qtail = tu->qused = 0;
1496 spin_unlock_irq(&tu->qlock);
1497
1498 return 0;
1499 }
1500
snd_timer_user_open(struct inode * inode,struct file * file)1501 static int snd_timer_user_open(struct inode *inode, struct file *file)
1502 {
1503 struct snd_timer_user *tu;
1504 int err;
1505
1506 err = stream_open(inode, file);
1507 if (err < 0)
1508 return err;
1509
1510 tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1511 if (tu == NULL)
1512 return -ENOMEM;
1513 spin_lock_init(&tu->qlock);
1514 init_waitqueue_head(&tu->qchange_sleep);
1515 mutex_init(&tu->ioctl_lock);
1516 tu->ticks = 1;
1517 if (realloc_user_queue(tu, 128) < 0) {
1518 kfree(tu);
1519 return -ENOMEM;
1520 }
1521 file->private_data = tu;
1522 return 0;
1523 }
1524
snd_timer_user_release(struct inode * inode,struct file * file)1525 static int snd_timer_user_release(struct inode *inode, struct file *file)
1526 {
1527 struct snd_timer_user *tu;
1528
1529 if (file->private_data) {
1530 tu = file->private_data;
1531 file->private_data = NULL;
1532 mutex_lock(&tu->ioctl_lock);
1533 if (tu->timeri) {
1534 snd_timer_close(tu->timeri);
1535 snd_timer_instance_free(tu->timeri);
1536 }
1537 mutex_unlock(&tu->ioctl_lock);
1538 snd_fasync_free(tu->fasync);
1539 kfree(tu->queue);
1540 kfree(tu->tqueue);
1541 kfree(tu);
1542 }
1543 return 0;
1544 }
1545
snd_timer_user_zero_id(struct snd_timer_id * id)1546 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1547 {
1548 id->dev_class = SNDRV_TIMER_CLASS_NONE;
1549 id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1550 id->card = -1;
1551 id->device = -1;
1552 id->subdevice = -1;
1553 }
1554
snd_timer_user_copy_id(struct snd_timer_id * id,struct snd_timer * timer)1555 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1556 {
1557 id->dev_class = timer->tmr_class;
1558 id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1559 id->card = timer->card ? timer->card->number : -1;
1560 id->device = timer->tmr_device;
1561 id->subdevice = timer->tmr_subdevice;
1562 }
1563
snd_timer_user_next_device(struct snd_timer_id __user * _tid)1564 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1565 {
1566 struct snd_timer_id id;
1567 struct snd_timer *timer;
1568 struct list_head *p;
1569
1570 if (copy_from_user(&id, _tid, sizeof(id)))
1571 return -EFAULT;
1572 mutex_lock(®ister_mutex);
1573 if (id.dev_class < 0) { /* first item */
1574 if (list_empty(&snd_timer_list))
1575 snd_timer_user_zero_id(&id);
1576 else {
1577 timer = list_entry(snd_timer_list.next,
1578 struct snd_timer, device_list);
1579 snd_timer_user_copy_id(&id, timer);
1580 }
1581 } else {
1582 switch (id.dev_class) {
1583 case SNDRV_TIMER_CLASS_GLOBAL:
1584 id.device = id.device < 0 ? 0 : id.device + 1;
1585 list_for_each(p, &snd_timer_list) {
1586 timer = list_entry(p, struct snd_timer, device_list);
1587 if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1588 snd_timer_user_copy_id(&id, timer);
1589 break;
1590 }
1591 if (timer->tmr_device >= id.device) {
1592 snd_timer_user_copy_id(&id, timer);
1593 break;
1594 }
1595 }
1596 if (p == &snd_timer_list)
1597 snd_timer_user_zero_id(&id);
1598 break;
1599 case SNDRV_TIMER_CLASS_CARD:
1600 case SNDRV_TIMER_CLASS_PCM:
1601 if (id.card < 0) {
1602 id.card = 0;
1603 } else {
1604 if (id.device < 0) {
1605 id.device = 0;
1606 } else {
1607 if (id.subdevice < 0)
1608 id.subdevice = 0;
1609 else if (id.subdevice < INT_MAX)
1610 id.subdevice++;
1611 }
1612 }
1613 list_for_each(p, &snd_timer_list) {
1614 timer = list_entry(p, struct snd_timer, device_list);
1615 if (timer->tmr_class > id.dev_class) {
1616 snd_timer_user_copy_id(&id, timer);
1617 break;
1618 }
1619 if (timer->tmr_class < id.dev_class)
1620 continue;
1621 if (timer->card->number > id.card) {
1622 snd_timer_user_copy_id(&id, timer);
1623 break;
1624 }
1625 if (timer->card->number < id.card)
1626 continue;
1627 if (timer->tmr_device > id.device) {
1628 snd_timer_user_copy_id(&id, timer);
1629 break;
1630 }
1631 if (timer->tmr_device < id.device)
1632 continue;
1633 if (timer->tmr_subdevice > id.subdevice) {
1634 snd_timer_user_copy_id(&id, timer);
1635 break;
1636 }
1637 if (timer->tmr_subdevice < id.subdevice)
1638 continue;
1639 snd_timer_user_copy_id(&id, timer);
1640 break;
1641 }
1642 if (p == &snd_timer_list)
1643 snd_timer_user_zero_id(&id);
1644 break;
1645 default:
1646 snd_timer_user_zero_id(&id);
1647 }
1648 }
1649 mutex_unlock(®ister_mutex);
1650 if (copy_to_user(_tid, &id, sizeof(*_tid)))
1651 return -EFAULT;
1652 return 0;
1653 }
1654
snd_timer_user_ginfo(struct file * file,struct snd_timer_ginfo __user * _ginfo)1655 static int snd_timer_user_ginfo(struct file *file,
1656 struct snd_timer_ginfo __user *_ginfo)
1657 {
1658 struct snd_timer_ginfo *ginfo;
1659 struct snd_timer_id tid;
1660 struct snd_timer *t;
1661 struct list_head *p;
1662 int err = 0;
1663
1664 ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1665 if (IS_ERR(ginfo))
1666 return PTR_ERR(ginfo);
1667
1668 tid = ginfo->tid;
1669 memset(ginfo, 0, sizeof(*ginfo));
1670 ginfo->tid = tid;
1671 mutex_lock(®ister_mutex);
1672 t = snd_timer_find(&tid);
1673 if (t != NULL) {
1674 ginfo->card = t->card ? t->card->number : -1;
1675 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1676 ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1677 strscpy(ginfo->id, t->id, sizeof(ginfo->id));
1678 strscpy(ginfo->name, t->name, sizeof(ginfo->name));
1679 spin_lock_irq(&t->lock);
1680 ginfo->resolution = snd_timer_hw_resolution(t);
1681 spin_unlock_irq(&t->lock);
1682 if (t->hw.resolution_min > 0) {
1683 ginfo->resolution_min = t->hw.resolution_min;
1684 ginfo->resolution_max = t->hw.resolution_max;
1685 }
1686 list_for_each(p, &t->open_list_head) {
1687 ginfo->clients++;
1688 }
1689 } else {
1690 err = -ENODEV;
1691 }
1692 mutex_unlock(®ister_mutex);
1693 if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1694 err = -EFAULT;
1695 kfree(ginfo);
1696 return err;
1697 }
1698
timer_set_gparams(struct snd_timer_gparams * gparams)1699 static int timer_set_gparams(struct snd_timer_gparams *gparams)
1700 {
1701 struct snd_timer *t;
1702 int err;
1703
1704 mutex_lock(®ister_mutex);
1705 t = snd_timer_find(&gparams->tid);
1706 if (!t) {
1707 err = -ENODEV;
1708 goto _error;
1709 }
1710 if (!list_empty(&t->open_list_head)) {
1711 err = -EBUSY;
1712 goto _error;
1713 }
1714 if (!t->hw.set_period) {
1715 err = -ENOSYS;
1716 goto _error;
1717 }
1718 err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
1719 _error:
1720 mutex_unlock(®ister_mutex);
1721 return err;
1722 }
1723
snd_timer_user_gparams(struct file * file,struct snd_timer_gparams __user * _gparams)1724 static int snd_timer_user_gparams(struct file *file,
1725 struct snd_timer_gparams __user *_gparams)
1726 {
1727 struct snd_timer_gparams gparams;
1728
1729 if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1730 return -EFAULT;
1731 return timer_set_gparams(&gparams);
1732 }
1733
snd_timer_user_gstatus(struct file * file,struct snd_timer_gstatus __user * _gstatus)1734 static int snd_timer_user_gstatus(struct file *file,
1735 struct snd_timer_gstatus __user *_gstatus)
1736 {
1737 struct snd_timer_gstatus gstatus;
1738 struct snd_timer_id tid;
1739 struct snd_timer *t;
1740 int err = 0;
1741
1742 if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1743 return -EFAULT;
1744 tid = gstatus.tid;
1745 memset(&gstatus, 0, sizeof(gstatus));
1746 gstatus.tid = tid;
1747 mutex_lock(®ister_mutex);
1748 t = snd_timer_find(&tid);
1749 if (t != NULL) {
1750 spin_lock_irq(&t->lock);
1751 gstatus.resolution = snd_timer_hw_resolution(t);
1752 if (t->hw.precise_resolution) {
1753 t->hw.precise_resolution(t, &gstatus.resolution_num,
1754 &gstatus.resolution_den);
1755 } else {
1756 gstatus.resolution_num = gstatus.resolution;
1757 gstatus.resolution_den = 1000000000uL;
1758 }
1759 spin_unlock_irq(&t->lock);
1760 } else {
1761 err = -ENODEV;
1762 }
1763 mutex_unlock(®ister_mutex);
1764 if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1765 err = -EFAULT;
1766 return err;
1767 }
1768
snd_timer_user_tselect(struct file * file,struct snd_timer_select __user * _tselect)1769 static int snd_timer_user_tselect(struct file *file,
1770 struct snd_timer_select __user *_tselect)
1771 {
1772 struct snd_timer_user *tu;
1773 struct snd_timer_select tselect;
1774 char str[32];
1775 int err = 0;
1776
1777 tu = file->private_data;
1778 if (tu->timeri) {
1779 snd_timer_close(tu->timeri);
1780 snd_timer_instance_free(tu->timeri);
1781 tu->timeri = NULL;
1782 }
1783 if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1784 err = -EFAULT;
1785 goto __err;
1786 }
1787 sprintf(str, "application %i", current->pid);
1788 if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1789 tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1790 tu->timeri = snd_timer_instance_new(str);
1791 if (!tu->timeri) {
1792 err = -ENOMEM;
1793 goto __err;
1794 }
1795
1796 tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1797 tu->timeri->callback = tu->tread
1798 ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1799 tu->timeri->ccallback = snd_timer_user_ccallback;
1800 tu->timeri->callback_data = (void *)tu;
1801 tu->timeri->disconnect = snd_timer_user_disconnect;
1802
1803 err = snd_timer_open(tu->timeri, &tselect.id, current->pid);
1804 if (err < 0) {
1805 snd_timer_instance_free(tu->timeri);
1806 tu->timeri = NULL;
1807 }
1808
1809 __err:
1810 return err;
1811 }
1812
snd_timer_user_info(struct file * file,struct snd_timer_info __user * _info)1813 static int snd_timer_user_info(struct file *file,
1814 struct snd_timer_info __user *_info)
1815 {
1816 struct snd_timer_user *tu;
1817 struct snd_timer_info *info;
1818 struct snd_timer *t;
1819 int err = 0;
1820
1821 tu = file->private_data;
1822 if (!tu->timeri)
1823 return -EBADFD;
1824 t = tu->timeri->timer;
1825 if (!t)
1826 return -EBADFD;
1827
1828 info = kzalloc(sizeof(*info), GFP_KERNEL);
1829 if (! info)
1830 return -ENOMEM;
1831 info->card = t->card ? t->card->number : -1;
1832 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1833 info->flags |= SNDRV_TIMER_FLG_SLAVE;
1834 strscpy(info->id, t->id, sizeof(info->id));
1835 strscpy(info->name, t->name, sizeof(info->name));
1836 spin_lock_irq(&t->lock);
1837 info->resolution = snd_timer_hw_resolution(t);
1838 spin_unlock_irq(&t->lock);
1839 if (copy_to_user(_info, info, sizeof(*_info)))
1840 err = -EFAULT;
1841 kfree(info);
1842 return err;
1843 }
1844
snd_timer_user_params(struct file * file,struct snd_timer_params __user * _params)1845 static int snd_timer_user_params(struct file *file,
1846 struct snd_timer_params __user *_params)
1847 {
1848 struct snd_timer_user *tu;
1849 struct snd_timer_params params;
1850 struct snd_timer *t;
1851 int err;
1852
1853 tu = file->private_data;
1854 if (!tu->timeri)
1855 return -EBADFD;
1856 t = tu->timeri->timer;
1857 if (!t)
1858 return -EBADFD;
1859 if (copy_from_user(¶ms, _params, sizeof(params)))
1860 return -EFAULT;
1861 if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
1862 u64 resolution;
1863
1864 if (params.ticks < 1) {
1865 err = -EINVAL;
1866 goto _end;
1867 }
1868
1869 /* Don't allow resolution less than 1ms */
1870 resolution = snd_timer_resolution(tu->timeri);
1871 resolution *= params.ticks;
1872 if (resolution < 1000000) {
1873 err = -EINVAL;
1874 goto _end;
1875 }
1876 }
1877 if (params.queue_size > 0 &&
1878 (params.queue_size < 32 || params.queue_size > 1024)) {
1879 err = -EINVAL;
1880 goto _end;
1881 }
1882 if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1883 (1<<SNDRV_TIMER_EVENT_TICK)|
1884 (1<<SNDRV_TIMER_EVENT_START)|
1885 (1<<SNDRV_TIMER_EVENT_STOP)|
1886 (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1887 (1<<SNDRV_TIMER_EVENT_PAUSE)|
1888 (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1889 (1<<SNDRV_TIMER_EVENT_RESUME)|
1890 (1<<SNDRV_TIMER_EVENT_MSTART)|
1891 (1<<SNDRV_TIMER_EVENT_MSTOP)|
1892 (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1893 (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1894 (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1895 (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1896 err = -EINVAL;
1897 goto _end;
1898 }
1899 snd_timer_stop(tu->timeri);
1900 spin_lock_irq(&t->lock);
1901 tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1902 SNDRV_TIMER_IFLG_EXCLUSIVE|
1903 SNDRV_TIMER_IFLG_EARLY_EVENT);
1904 if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1905 tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1906 if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1907 tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1908 if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1909 tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1910 spin_unlock_irq(&t->lock);
1911 if (params.queue_size > 0 &&
1912 (unsigned int)tu->queue_size != params.queue_size) {
1913 err = realloc_user_queue(tu, params.queue_size);
1914 if (err < 0)
1915 goto _end;
1916 }
1917 spin_lock_irq(&tu->qlock);
1918 tu->qhead = tu->qtail = tu->qused = 0;
1919 if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1920 if (tu->tread) {
1921 struct snd_timer_tread64 tread;
1922 memset(&tread, 0, sizeof(tread));
1923 tread.event = SNDRV_TIMER_EVENT_EARLY;
1924 tread.tstamp_sec = 0;
1925 tread.tstamp_nsec = 0;
1926 tread.val = 0;
1927 snd_timer_user_append_to_tqueue(tu, &tread);
1928 } else {
1929 struct snd_timer_read *r = &tu->queue[0];
1930 r->resolution = 0;
1931 r->ticks = 0;
1932 tu->qused++;
1933 tu->qtail++;
1934 }
1935 }
1936 tu->filter = params.filter;
1937 tu->ticks = params.ticks;
1938 spin_unlock_irq(&tu->qlock);
1939 err = 0;
1940 _end:
1941 if (copy_to_user(_params, ¶ms, sizeof(params)))
1942 return -EFAULT;
1943 return err;
1944 }
1945
snd_timer_user_status32(struct file * file,struct snd_timer_status32 __user * _status)1946 static int snd_timer_user_status32(struct file *file,
1947 struct snd_timer_status32 __user *_status)
1948 {
1949 struct snd_timer_user *tu;
1950 struct snd_timer_status32 status;
1951
1952 tu = file->private_data;
1953 if (!tu->timeri)
1954 return -EBADFD;
1955 memset(&status, 0, sizeof(status));
1956 status.tstamp_sec = tu->tstamp.tv_sec;
1957 status.tstamp_nsec = tu->tstamp.tv_nsec;
1958 status.resolution = snd_timer_resolution(tu->timeri);
1959 status.lost = tu->timeri->lost;
1960 status.overrun = tu->overrun;
1961 spin_lock_irq(&tu->qlock);
1962 status.queue = tu->qused;
1963 spin_unlock_irq(&tu->qlock);
1964 if (copy_to_user(_status, &status, sizeof(status)))
1965 return -EFAULT;
1966 return 0;
1967 }
1968
snd_timer_user_status64(struct file * file,struct snd_timer_status64 __user * _status)1969 static int snd_timer_user_status64(struct file *file,
1970 struct snd_timer_status64 __user *_status)
1971 {
1972 struct snd_timer_user *tu;
1973 struct snd_timer_status64 status;
1974
1975 tu = file->private_data;
1976 if (!tu->timeri)
1977 return -EBADFD;
1978 memset(&status, 0, sizeof(status));
1979 status.tstamp_sec = tu->tstamp.tv_sec;
1980 status.tstamp_nsec = tu->tstamp.tv_nsec;
1981 status.resolution = snd_timer_resolution(tu->timeri);
1982 status.lost = tu->timeri->lost;
1983 status.overrun = tu->overrun;
1984 spin_lock_irq(&tu->qlock);
1985 status.queue = tu->qused;
1986 spin_unlock_irq(&tu->qlock);
1987 if (copy_to_user(_status, &status, sizeof(status)))
1988 return -EFAULT;
1989 return 0;
1990 }
1991
snd_timer_user_start(struct file * file)1992 static int snd_timer_user_start(struct file *file)
1993 {
1994 int err;
1995 struct snd_timer_user *tu;
1996
1997 tu = file->private_data;
1998 if (!tu->timeri)
1999 return -EBADFD;
2000 snd_timer_stop(tu->timeri);
2001 tu->timeri->lost = 0;
2002 tu->last_resolution = 0;
2003 err = snd_timer_start(tu->timeri, tu->ticks);
2004 if (err < 0)
2005 return err;
2006 return 0;
2007 }
2008
snd_timer_user_stop(struct file * file)2009 static int snd_timer_user_stop(struct file *file)
2010 {
2011 int err;
2012 struct snd_timer_user *tu;
2013
2014 tu = file->private_data;
2015 if (!tu->timeri)
2016 return -EBADFD;
2017 err = snd_timer_stop(tu->timeri);
2018 if (err < 0)
2019 return err;
2020 return 0;
2021 }
2022
snd_timer_user_continue(struct file * file)2023 static int snd_timer_user_continue(struct file *file)
2024 {
2025 int err;
2026 struct snd_timer_user *tu;
2027
2028 tu = file->private_data;
2029 if (!tu->timeri)
2030 return -EBADFD;
2031 /* start timer instead of continue if it's not used before */
2032 if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
2033 return snd_timer_user_start(file);
2034 tu->timeri->lost = 0;
2035 err = snd_timer_continue(tu->timeri);
2036 if (err < 0)
2037 return err;
2038 return 0;
2039 }
2040
snd_timer_user_pause(struct file * file)2041 static int snd_timer_user_pause(struct file *file)
2042 {
2043 int err;
2044 struct snd_timer_user *tu;
2045
2046 tu = file->private_data;
2047 if (!tu->timeri)
2048 return -EBADFD;
2049 err = snd_timer_pause(tu->timeri);
2050 if (err < 0)
2051 return err;
2052 return 0;
2053 }
2054
snd_timer_user_tread(void __user * argp,struct snd_timer_user * tu,unsigned int cmd,bool compat)2055 static int snd_timer_user_tread(void __user *argp, struct snd_timer_user *tu,
2056 unsigned int cmd, bool compat)
2057 {
2058 int __user *p = argp;
2059 int xarg, old_tread;
2060
2061 if (tu->timeri) /* too late */
2062 return -EBUSY;
2063 if (get_user(xarg, p))
2064 return -EFAULT;
2065
2066 old_tread = tu->tread;
2067
2068 if (!xarg)
2069 tu->tread = TREAD_FORMAT_NONE;
2070 else if (cmd == SNDRV_TIMER_IOCTL_TREAD64 ||
2071 (IS_ENABLED(CONFIG_64BIT) && !compat))
2072 tu->tread = TREAD_FORMAT_TIME64;
2073 else
2074 tu->tread = TREAD_FORMAT_TIME32;
2075
2076 if (tu->tread != old_tread &&
2077 realloc_user_queue(tu, tu->queue_size) < 0) {
2078 tu->tread = old_tread;
2079 return -ENOMEM;
2080 }
2081
2082 return 0;
2083 }
2084
2085 enum {
2086 SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
2087 SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
2088 SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
2089 SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
2090 };
2091
__snd_timer_user_ioctl(struct file * file,unsigned int cmd,unsigned long arg,bool compat)2092 static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2093 unsigned long arg, bool compat)
2094 {
2095 struct snd_timer_user *tu;
2096 void __user *argp = (void __user *)arg;
2097 int __user *p = argp;
2098
2099 tu = file->private_data;
2100 switch (cmd) {
2101 case SNDRV_TIMER_IOCTL_PVERSION:
2102 return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
2103 case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
2104 return snd_timer_user_next_device(argp);
2105 case SNDRV_TIMER_IOCTL_TREAD_OLD:
2106 case SNDRV_TIMER_IOCTL_TREAD64:
2107 return snd_timer_user_tread(argp, tu, cmd, compat);
2108 case SNDRV_TIMER_IOCTL_GINFO:
2109 return snd_timer_user_ginfo(file, argp);
2110 case SNDRV_TIMER_IOCTL_GPARAMS:
2111 return snd_timer_user_gparams(file, argp);
2112 case SNDRV_TIMER_IOCTL_GSTATUS:
2113 return snd_timer_user_gstatus(file, argp);
2114 case SNDRV_TIMER_IOCTL_SELECT:
2115 return snd_timer_user_tselect(file, argp);
2116 case SNDRV_TIMER_IOCTL_INFO:
2117 return snd_timer_user_info(file, argp);
2118 case SNDRV_TIMER_IOCTL_PARAMS:
2119 return snd_timer_user_params(file, argp);
2120 case SNDRV_TIMER_IOCTL_STATUS32:
2121 return snd_timer_user_status32(file, argp);
2122 case SNDRV_TIMER_IOCTL_STATUS64:
2123 return snd_timer_user_status64(file, argp);
2124 case SNDRV_TIMER_IOCTL_START:
2125 case SNDRV_TIMER_IOCTL_START_OLD:
2126 return snd_timer_user_start(file);
2127 case SNDRV_TIMER_IOCTL_STOP:
2128 case SNDRV_TIMER_IOCTL_STOP_OLD:
2129 return snd_timer_user_stop(file);
2130 case SNDRV_TIMER_IOCTL_CONTINUE:
2131 case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
2132 return snd_timer_user_continue(file);
2133 case SNDRV_TIMER_IOCTL_PAUSE:
2134 case SNDRV_TIMER_IOCTL_PAUSE_OLD:
2135 return snd_timer_user_pause(file);
2136 }
2137 return -ENOTTY;
2138 }
2139
snd_timer_user_ioctl(struct file * file,unsigned int cmd,unsigned long arg)2140 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2141 unsigned long arg)
2142 {
2143 struct snd_timer_user *tu = file->private_data;
2144 long ret;
2145
2146 mutex_lock(&tu->ioctl_lock);
2147 ret = __snd_timer_user_ioctl(file, cmd, arg, false);
2148 mutex_unlock(&tu->ioctl_lock);
2149 return ret;
2150 }
2151
snd_timer_user_fasync(int fd,struct file * file,int on)2152 static int snd_timer_user_fasync(int fd, struct file * file, int on)
2153 {
2154 struct snd_timer_user *tu;
2155
2156 tu = file->private_data;
2157 return snd_fasync_helper(fd, file, on, &tu->fasync);
2158 }
2159
snd_timer_user_read(struct file * file,char __user * buffer,size_t count,loff_t * offset)2160 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
2161 size_t count, loff_t *offset)
2162 {
2163 struct snd_timer_tread64 *tread;
2164 struct snd_timer_tread32 tread32;
2165 struct snd_timer_user *tu;
2166 long result = 0, unit;
2167 int qhead;
2168 int err = 0;
2169
2170 tu = file->private_data;
2171 switch (tu->tread) {
2172 case TREAD_FORMAT_TIME64:
2173 unit = sizeof(struct snd_timer_tread64);
2174 break;
2175 case TREAD_FORMAT_TIME32:
2176 unit = sizeof(struct snd_timer_tread32);
2177 break;
2178 case TREAD_FORMAT_NONE:
2179 unit = sizeof(struct snd_timer_read);
2180 break;
2181 default:
2182 WARN_ONCE(1, "Corrupt snd_timer_user\n");
2183 return -ENOTSUPP;
2184 }
2185
2186 mutex_lock(&tu->ioctl_lock);
2187 spin_lock_irq(&tu->qlock);
2188 while ((long)count - result >= unit) {
2189 while (!tu->qused) {
2190 wait_queue_entry_t wait;
2191
2192 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
2193 err = -EAGAIN;
2194 goto _error;
2195 }
2196
2197 set_current_state(TASK_INTERRUPTIBLE);
2198 init_waitqueue_entry(&wait, current);
2199 add_wait_queue(&tu->qchange_sleep, &wait);
2200
2201 spin_unlock_irq(&tu->qlock);
2202 mutex_unlock(&tu->ioctl_lock);
2203 schedule();
2204 mutex_lock(&tu->ioctl_lock);
2205 spin_lock_irq(&tu->qlock);
2206
2207 remove_wait_queue(&tu->qchange_sleep, &wait);
2208
2209 if (tu->disconnected) {
2210 err = -ENODEV;
2211 goto _error;
2212 }
2213 if (signal_pending(current)) {
2214 err = -ERESTARTSYS;
2215 goto _error;
2216 }
2217 }
2218
2219 qhead = tu->qhead++;
2220 tu->qhead %= tu->queue_size;
2221 tu->qused--;
2222 spin_unlock_irq(&tu->qlock);
2223
2224 tread = &tu->tqueue[qhead];
2225
2226 switch (tu->tread) {
2227 case TREAD_FORMAT_TIME64:
2228 if (copy_to_user(buffer, tread,
2229 sizeof(struct snd_timer_tread64)))
2230 err = -EFAULT;
2231 break;
2232 case TREAD_FORMAT_TIME32:
2233 memset(&tread32, 0, sizeof(tread32));
2234 tread32 = (struct snd_timer_tread32) {
2235 .event = tread->event,
2236 .tstamp_sec = tread->tstamp_sec,
2237 .tstamp_nsec = tread->tstamp_nsec,
2238 .val = tread->val,
2239 };
2240
2241 if (copy_to_user(buffer, &tread32, sizeof(tread32)))
2242 err = -EFAULT;
2243 break;
2244 case TREAD_FORMAT_NONE:
2245 if (copy_to_user(buffer, &tu->queue[qhead],
2246 sizeof(struct snd_timer_read)))
2247 err = -EFAULT;
2248 break;
2249 default:
2250 err = -ENOTSUPP;
2251 break;
2252 }
2253
2254 spin_lock_irq(&tu->qlock);
2255 if (err < 0)
2256 goto _error;
2257 result += unit;
2258 buffer += unit;
2259 }
2260 _error:
2261 spin_unlock_irq(&tu->qlock);
2262 mutex_unlock(&tu->ioctl_lock);
2263 return result > 0 ? result : err;
2264 }
2265
snd_timer_user_poll(struct file * file,poll_table * wait)2266 static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
2267 {
2268 __poll_t mask;
2269 struct snd_timer_user *tu;
2270
2271 tu = file->private_data;
2272
2273 poll_wait(file, &tu->qchange_sleep, wait);
2274
2275 mask = 0;
2276 spin_lock_irq(&tu->qlock);
2277 if (tu->qused)
2278 mask |= EPOLLIN | EPOLLRDNORM;
2279 if (tu->disconnected)
2280 mask |= EPOLLERR;
2281 spin_unlock_irq(&tu->qlock);
2282
2283 return mask;
2284 }
2285
2286 #ifdef CONFIG_COMPAT
2287 #include "timer_compat.c"
2288 #else
2289 #define snd_timer_user_ioctl_compat NULL
2290 #endif
2291
2292 static const struct file_operations snd_timer_f_ops =
2293 {
2294 .owner = THIS_MODULE,
2295 .read = snd_timer_user_read,
2296 .open = snd_timer_user_open,
2297 .release = snd_timer_user_release,
2298 .llseek = no_llseek,
2299 .poll = snd_timer_user_poll,
2300 .unlocked_ioctl = snd_timer_user_ioctl,
2301 .compat_ioctl = snd_timer_user_ioctl_compat,
2302 .fasync = snd_timer_user_fasync,
2303 };
2304
2305 /* unregister the system timer */
snd_timer_free_all(void)2306 static void snd_timer_free_all(void)
2307 {
2308 struct snd_timer *timer, *n;
2309
2310 list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2311 snd_timer_free(timer);
2312 }
2313
2314 static struct device *timer_dev;
2315
2316 /*
2317 * ENTRY functions
2318 */
2319
alsa_timer_init(void)2320 static int __init alsa_timer_init(void)
2321 {
2322 int err;
2323
2324 err = snd_device_alloc(&timer_dev, NULL);
2325 if (err < 0)
2326 return err;
2327 dev_set_name(timer_dev, "timer");
2328
2329 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2330 snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2331 "system timer");
2332 #endif
2333
2334 err = snd_timer_register_system();
2335 if (err < 0) {
2336 pr_err("ALSA: unable to register system timer (%i)\n", err);
2337 goto put_timer;
2338 }
2339
2340 err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
2341 &snd_timer_f_ops, NULL, timer_dev);
2342 if (err < 0) {
2343 pr_err("ALSA: unable to register timer device (%i)\n", err);
2344 snd_timer_free_all();
2345 goto put_timer;
2346 }
2347
2348 snd_timer_proc_init();
2349 return 0;
2350
2351 put_timer:
2352 put_device(timer_dev);
2353 return err;
2354 }
2355
alsa_timer_exit(void)2356 static void __exit alsa_timer_exit(void)
2357 {
2358 snd_unregister_device(timer_dev);
2359 snd_timer_free_all();
2360 put_device(timer_dev);
2361 snd_timer_proc_done();
2362 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2363 snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2364 #endif
2365 }
2366
2367 module_init(alsa_timer_init)
2368 module_exit(alsa_timer_exit)
2369