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 if (start)
557 timeri->ticks = timeri->cticks = ticks;
558 else if (!timeri->cticks)
559 timeri->cticks = 1;
560 timeri->pticks = 0;
561
562 list_move_tail(&timeri->active_list, &timer->active_list_head);
563 if (timer->running) {
564 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
565 goto __start_now;
566 timer->flags |= SNDRV_TIMER_FLG_RESCHED;
567 timeri->flags |= SNDRV_TIMER_IFLG_START;
568 result = 1; /* delayed start */
569 } else {
570 if (start)
571 timer->sticks = ticks;
572 timer->hw.start(timer);
573 __start_now:
574 timer->running++;
575 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
576 result = 0;
577 }
578 snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
579 SNDRV_TIMER_EVENT_CONTINUE);
580 unlock:
581 spin_unlock_irqrestore(&timer->lock, flags);
582 return result;
583 }
584
585 /* start/continue a slave timer */
snd_timer_start_slave(struct snd_timer_instance * timeri,bool start)586 static int snd_timer_start_slave(struct snd_timer_instance *timeri,
587 bool start)
588 {
589 unsigned long flags;
590 int err;
591
592 spin_lock_irqsave(&slave_active_lock, flags);
593 if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
594 err = -EINVAL;
595 goto unlock;
596 }
597 if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
598 err = -EBUSY;
599 goto unlock;
600 }
601 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
602 if (timeri->master && timeri->timer) {
603 spin_lock(&timeri->timer->lock);
604 list_add_tail(&timeri->active_list,
605 &timeri->master->slave_active_head);
606 snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
607 SNDRV_TIMER_EVENT_CONTINUE);
608 spin_unlock(&timeri->timer->lock);
609 }
610 err = 1; /* delayed start */
611 unlock:
612 spin_unlock_irqrestore(&slave_active_lock, flags);
613 return err;
614 }
615
616 /* stop/pause a master timer */
snd_timer_stop1(struct snd_timer_instance * timeri,bool stop)617 static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
618 {
619 struct snd_timer *timer;
620 int result = 0;
621 unsigned long flags;
622
623 timer = timeri->timer;
624 if (!timer)
625 return -EINVAL;
626 spin_lock_irqsave(&timer->lock, flags);
627 list_del_init(&timeri->ack_list);
628 list_del_init(&timeri->active_list);
629 if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
630 SNDRV_TIMER_IFLG_START))) {
631 result = -EBUSY;
632 goto unlock;
633 }
634 if (timer->card && timer->card->shutdown)
635 goto unlock;
636 if (stop) {
637 timeri->cticks = timeri->ticks;
638 timeri->pticks = 0;
639 }
640 if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
641 !(--timer->running)) {
642 timer->hw.stop(timer);
643 if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
644 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
645 snd_timer_reschedule(timer, 0);
646 if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
647 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
648 timer->hw.start(timer);
649 }
650 }
651 }
652 timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
653 if (stop)
654 timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
655 else
656 timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
657 snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
658 SNDRV_TIMER_EVENT_PAUSE);
659 unlock:
660 spin_unlock_irqrestore(&timer->lock, flags);
661 return result;
662 }
663
664 /* stop/pause a slave timer */
snd_timer_stop_slave(struct snd_timer_instance * timeri,bool stop)665 static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
666 {
667 unsigned long flags;
668 bool running;
669
670 spin_lock_irqsave(&slave_active_lock, flags);
671 running = timeri->flags & SNDRV_TIMER_IFLG_RUNNING;
672 timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
673 if (timeri->timer) {
674 spin_lock(&timeri->timer->lock);
675 list_del_init(&timeri->ack_list);
676 list_del_init(&timeri->active_list);
677 if (running)
678 snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
679 SNDRV_TIMER_EVENT_PAUSE);
680 spin_unlock(&timeri->timer->lock);
681 }
682 spin_unlock_irqrestore(&slave_active_lock, flags);
683 return running ? 0 : -EBUSY;
684 }
685
686 /*
687 * start the timer instance
688 */
snd_timer_start(struct snd_timer_instance * timeri,unsigned int ticks)689 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
690 {
691 if (timeri == NULL || ticks < 1)
692 return -EINVAL;
693 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
694 return snd_timer_start_slave(timeri, true);
695 else
696 return snd_timer_start1(timeri, true, ticks);
697 }
698 EXPORT_SYMBOL(snd_timer_start);
699
700 /*
701 * stop the timer instance.
702 *
703 * do not call this from the timer callback!
704 */
snd_timer_stop(struct snd_timer_instance * timeri)705 int snd_timer_stop(struct snd_timer_instance *timeri)
706 {
707 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
708 return snd_timer_stop_slave(timeri, true);
709 else
710 return snd_timer_stop1(timeri, true);
711 }
712 EXPORT_SYMBOL(snd_timer_stop);
713
714 /*
715 * start again.. the tick is kept.
716 */
snd_timer_continue(struct snd_timer_instance * timeri)717 int snd_timer_continue(struct snd_timer_instance *timeri)
718 {
719 /* timer can continue only after pause */
720 if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
721 return -EINVAL;
722
723 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
724 return snd_timer_start_slave(timeri, false);
725 else
726 return snd_timer_start1(timeri, false, 0);
727 }
728 EXPORT_SYMBOL(snd_timer_continue);
729
730 /*
731 * pause.. remember the ticks left
732 */
snd_timer_pause(struct snd_timer_instance * timeri)733 int snd_timer_pause(struct snd_timer_instance * timeri)
734 {
735 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
736 return snd_timer_stop_slave(timeri, false);
737 else
738 return snd_timer_stop1(timeri, false);
739 }
740 EXPORT_SYMBOL(snd_timer_pause);
741
742 /*
743 * reschedule the timer
744 *
745 * start pending instances and check the scheduling ticks.
746 * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
747 */
snd_timer_reschedule(struct snd_timer * timer,unsigned long ticks_left)748 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
749 {
750 struct snd_timer_instance *ti;
751 unsigned long ticks = ~0UL;
752
753 list_for_each_entry(ti, &timer->active_list_head, active_list) {
754 if (ti->flags & SNDRV_TIMER_IFLG_START) {
755 ti->flags &= ~SNDRV_TIMER_IFLG_START;
756 ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
757 timer->running++;
758 }
759 if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
760 if (ticks > ti->cticks)
761 ticks = ti->cticks;
762 }
763 }
764 if (ticks == ~0UL) {
765 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
766 return;
767 }
768 if (ticks > timer->hw.ticks)
769 ticks = timer->hw.ticks;
770 if (ticks_left != ticks)
771 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
772 timer->sticks = ticks;
773 }
774
775 /* call callbacks in timer ack list */
snd_timer_process_callbacks(struct snd_timer * timer,struct list_head * head)776 static void snd_timer_process_callbacks(struct snd_timer *timer,
777 struct list_head *head)
778 {
779 struct snd_timer_instance *ti;
780 unsigned long resolution, ticks;
781
782 while (!list_empty(head)) {
783 ti = list_first_entry(head, struct snd_timer_instance,
784 ack_list);
785
786 /* remove from ack_list and make empty */
787 list_del_init(&ti->ack_list);
788
789 if (!(ti->flags & SNDRV_TIMER_IFLG_DEAD)) {
790 ticks = ti->pticks;
791 ti->pticks = 0;
792 resolution = ti->resolution;
793 ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
794 spin_unlock(&timer->lock);
795 if (ti->callback)
796 ti->callback(ti, resolution, ticks);
797 spin_lock(&timer->lock);
798 ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
799 }
800 }
801 }
802
803 /* clear pending instances from ack list */
snd_timer_clear_callbacks(struct snd_timer * timer,struct list_head * head)804 static void snd_timer_clear_callbacks(struct snd_timer *timer,
805 struct list_head *head)
806 {
807 unsigned long flags;
808
809 spin_lock_irqsave(&timer->lock, flags);
810 while (!list_empty(head))
811 list_del_init(head->next);
812 spin_unlock_irqrestore(&timer->lock, flags);
813 }
814
815 /*
816 * timer work
817 *
818 */
snd_timer_work(struct work_struct * work)819 static void snd_timer_work(struct work_struct *work)
820 {
821 struct snd_timer *timer = container_of(work, struct snd_timer, task_work);
822 unsigned long flags;
823
824 if (timer->card && timer->card->shutdown) {
825 snd_timer_clear_callbacks(timer, &timer->sack_list_head);
826 return;
827 }
828
829 spin_lock_irqsave(&timer->lock, flags);
830 snd_timer_process_callbacks(timer, &timer->sack_list_head);
831 spin_unlock_irqrestore(&timer->lock, flags);
832 }
833
834 /*
835 * timer interrupt
836 *
837 * ticks_left is usually equal to timer->sticks.
838 *
839 */
snd_timer_interrupt(struct snd_timer * timer,unsigned long ticks_left)840 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
841 {
842 struct snd_timer_instance *ti, *ts, *tmp;
843 unsigned long resolution;
844 struct list_head *ack_list_head;
845 unsigned long flags;
846 bool use_work = false;
847
848 if (timer == NULL)
849 return;
850
851 if (timer->card && timer->card->shutdown) {
852 snd_timer_clear_callbacks(timer, &timer->ack_list_head);
853 return;
854 }
855
856 spin_lock_irqsave(&timer->lock, flags);
857
858 /* remember the current resolution */
859 resolution = snd_timer_hw_resolution(timer);
860
861 /* loop for all active instances
862 * Here we cannot use list_for_each_entry because the active_list of a
863 * processed instance is relinked to done_list_head before the callback
864 * is called.
865 */
866 list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
867 active_list) {
868 if (ti->flags & SNDRV_TIMER_IFLG_DEAD)
869 continue;
870 if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
871 continue;
872 ti->pticks += ticks_left;
873 ti->resolution = resolution;
874 if (ti->cticks < ticks_left)
875 ti->cticks = 0;
876 else
877 ti->cticks -= ticks_left;
878 if (ti->cticks) /* not expired */
879 continue;
880 if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
881 ti->cticks = ti->ticks;
882 } else {
883 ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
884 --timer->running;
885 list_del_init(&ti->active_list);
886 }
887 if ((timer->hw.flags & SNDRV_TIMER_HW_WORK) ||
888 (ti->flags & SNDRV_TIMER_IFLG_FAST))
889 ack_list_head = &timer->ack_list_head;
890 else
891 ack_list_head = &timer->sack_list_head;
892 if (list_empty(&ti->ack_list))
893 list_add_tail(&ti->ack_list, ack_list_head);
894 list_for_each_entry(ts, &ti->slave_active_head, active_list) {
895 ts->pticks = ti->pticks;
896 ts->resolution = resolution;
897 if (list_empty(&ts->ack_list))
898 list_add_tail(&ts->ack_list, ack_list_head);
899 }
900 }
901 if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
902 snd_timer_reschedule(timer, timer->sticks);
903 if (timer->running) {
904 if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
905 timer->hw.stop(timer);
906 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
907 }
908 if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
909 (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
910 /* restart timer */
911 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
912 timer->hw.start(timer);
913 }
914 } else {
915 timer->hw.stop(timer);
916 }
917
918 /* now process all fast callbacks */
919 snd_timer_process_callbacks(timer, &timer->ack_list_head);
920
921 /* do we have any slow callbacks? */
922 use_work = !list_empty(&timer->sack_list_head);
923 spin_unlock_irqrestore(&timer->lock, flags);
924
925 if (use_work)
926 queue_work(system_highpri_wq, &timer->task_work);
927 }
928 EXPORT_SYMBOL(snd_timer_interrupt);
929
930 /*
931
932 */
933
snd_timer_new(struct snd_card * card,char * id,struct snd_timer_id * tid,struct snd_timer ** rtimer)934 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
935 struct snd_timer **rtimer)
936 {
937 struct snd_timer *timer;
938 int err;
939 static const struct snd_device_ops ops = {
940 .dev_free = snd_timer_dev_free,
941 .dev_register = snd_timer_dev_register,
942 .dev_disconnect = snd_timer_dev_disconnect,
943 };
944
945 if (snd_BUG_ON(!tid))
946 return -EINVAL;
947 if (tid->dev_class == SNDRV_TIMER_CLASS_CARD ||
948 tid->dev_class == SNDRV_TIMER_CLASS_PCM) {
949 if (WARN_ON(!card))
950 return -EINVAL;
951 }
952 if (rtimer)
953 *rtimer = NULL;
954 timer = kzalloc(sizeof(*timer), GFP_KERNEL);
955 if (!timer)
956 return -ENOMEM;
957 timer->tmr_class = tid->dev_class;
958 timer->card = card;
959 timer->tmr_device = tid->device;
960 timer->tmr_subdevice = tid->subdevice;
961 if (id)
962 strlcpy(timer->id, id, sizeof(timer->id));
963 timer->sticks = 1;
964 INIT_LIST_HEAD(&timer->device_list);
965 INIT_LIST_HEAD(&timer->open_list_head);
966 INIT_LIST_HEAD(&timer->active_list_head);
967 INIT_LIST_HEAD(&timer->ack_list_head);
968 INIT_LIST_HEAD(&timer->sack_list_head);
969 spin_lock_init(&timer->lock);
970 INIT_WORK(&timer->task_work, snd_timer_work);
971 timer->max_instances = 1000; /* default limit per timer */
972 if (card != NULL) {
973 timer->module = card->module;
974 err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
975 if (err < 0) {
976 snd_timer_free(timer);
977 return err;
978 }
979 }
980 if (rtimer)
981 *rtimer = timer;
982 return 0;
983 }
984 EXPORT_SYMBOL(snd_timer_new);
985
snd_timer_free(struct snd_timer * timer)986 static int snd_timer_free(struct snd_timer *timer)
987 {
988 if (!timer)
989 return 0;
990
991 mutex_lock(®ister_mutex);
992 if (! list_empty(&timer->open_list_head)) {
993 struct list_head *p, *n;
994 struct snd_timer_instance *ti;
995 pr_warn("ALSA: timer %p is busy?\n", timer);
996 list_for_each_safe(p, n, &timer->open_list_head) {
997 list_del_init(p);
998 ti = list_entry(p, struct snd_timer_instance, open_list);
999 ti->timer = NULL;
1000 }
1001 }
1002 list_del(&timer->device_list);
1003 mutex_unlock(®ister_mutex);
1004
1005 if (timer->private_free)
1006 timer->private_free(timer);
1007 kfree(timer);
1008 return 0;
1009 }
1010
snd_timer_dev_free(struct snd_device * device)1011 static int snd_timer_dev_free(struct snd_device *device)
1012 {
1013 struct snd_timer *timer = device->device_data;
1014 return snd_timer_free(timer);
1015 }
1016
snd_timer_dev_register(struct snd_device * dev)1017 static int snd_timer_dev_register(struct snd_device *dev)
1018 {
1019 struct snd_timer *timer = dev->device_data;
1020 struct snd_timer *timer1;
1021
1022 if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
1023 return -ENXIO;
1024 if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
1025 !timer->hw.resolution && timer->hw.c_resolution == NULL)
1026 return -EINVAL;
1027
1028 mutex_lock(®ister_mutex);
1029 list_for_each_entry(timer1, &snd_timer_list, device_list) {
1030 if (timer1->tmr_class > timer->tmr_class)
1031 break;
1032 if (timer1->tmr_class < timer->tmr_class)
1033 continue;
1034 if (timer1->card && timer->card) {
1035 if (timer1->card->number > timer->card->number)
1036 break;
1037 if (timer1->card->number < timer->card->number)
1038 continue;
1039 }
1040 if (timer1->tmr_device > timer->tmr_device)
1041 break;
1042 if (timer1->tmr_device < timer->tmr_device)
1043 continue;
1044 if (timer1->tmr_subdevice > timer->tmr_subdevice)
1045 break;
1046 if (timer1->tmr_subdevice < timer->tmr_subdevice)
1047 continue;
1048 /* conflicts.. */
1049 mutex_unlock(®ister_mutex);
1050 return -EBUSY;
1051 }
1052 list_add_tail(&timer->device_list, &timer1->device_list);
1053 mutex_unlock(®ister_mutex);
1054 return 0;
1055 }
1056
snd_timer_dev_disconnect(struct snd_device * device)1057 static int snd_timer_dev_disconnect(struct snd_device *device)
1058 {
1059 struct snd_timer *timer = device->device_data;
1060 struct snd_timer_instance *ti;
1061
1062 mutex_lock(®ister_mutex);
1063 list_del_init(&timer->device_list);
1064 /* wake up pending sleepers */
1065 list_for_each_entry(ti, &timer->open_list_head, open_list) {
1066 if (ti->disconnect)
1067 ti->disconnect(ti);
1068 }
1069 mutex_unlock(®ister_mutex);
1070 return 0;
1071 }
1072
snd_timer_notify(struct snd_timer * timer,int event,struct timespec64 * tstamp)1073 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp)
1074 {
1075 unsigned long flags;
1076 unsigned long resolution = 0;
1077 struct snd_timer_instance *ti, *ts;
1078
1079 if (timer->card && timer->card->shutdown)
1080 return;
1081 if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
1082 return;
1083 if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
1084 event > SNDRV_TIMER_EVENT_MRESUME))
1085 return;
1086 spin_lock_irqsave(&timer->lock, flags);
1087 if (event == SNDRV_TIMER_EVENT_MSTART ||
1088 event == SNDRV_TIMER_EVENT_MCONTINUE ||
1089 event == SNDRV_TIMER_EVENT_MRESUME)
1090 resolution = snd_timer_hw_resolution(timer);
1091 list_for_each_entry(ti, &timer->active_list_head, active_list) {
1092 if (ti->ccallback)
1093 ti->ccallback(ti, event, tstamp, resolution);
1094 list_for_each_entry(ts, &ti->slave_active_head, active_list)
1095 if (ts->ccallback)
1096 ts->ccallback(ts, event, tstamp, resolution);
1097 }
1098 spin_unlock_irqrestore(&timer->lock, flags);
1099 }
1100 EXPORT_SYMBOL(snd_timer_notify);
1101
1102 /*
1103 * exported functions for global timers
1104 */
snd_timer_global_new(char * id,int device,struct snd_timer ** rtimer)1105 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
1106 {
1107 struct snd_timer_id tid;
1108
1109 tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
1110 tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1111 tid.card = -1;
1112 tid.device = device;
1113 tid.subdevice = 0;
1114 return snd_timer_new(NULL, id, &tid, rtimer);
1115 }
1116 EXPORT_SYMBOL(snd_timer_global_new);
1117
snd_timer_global_free(struct snd_timer * timer)1118 int snd_timer_global_free(struct snd_timer *timer)
1119 {
1120 return snd_timer_free(timer);
1121 }
1122 EXPORT_SYMBOL(snd_timer_global_free);
1123
snd_timer_global_register(struct snd_timer * timer)1124 int snd_timer_global_register(struct snd_timer *timer)
1125 {
1126 struct snd_device dev;
1127
1128 memset(&dev, 0, sizeof(dev));
1129 dev.device_data = timer;
1130 return snd_timer_dev_register(&dev);
1131 }
1132 EXPORT_SYMBOL(snd_timer_global_register);
1133
1134 /*
1135 * System timer
1136 */
1137
1138 struct snd_timer_system_private {
1139 struct timer_list tlist;
1140 struct snd_timer *snd_timer;
1141 unsigned long last_expires;
1142 unsigned long last_jiffies;
1143 unsigned long correction;
1144 };
1145
snd_timer_s_function(struct timer_list * t)1146 static void snd_timer_s_function(struct timer_list *t)
1147 {
1148 struct snd_timer_system_private *priv = from_timer(priv, t,
1149 tlist);
1150 struct snd_timer *timer = priv->snd_timer;
1151 unsigned long jiff = jiffies;
1152 if (time_after(jiff, priv->last_expires))
1153 priv->correction += (long)jiff - (long)priv->last_expires;
1154 snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
1155 }
1156
snd_timer_s_start(struct snd_timer * timer)1157 static int snd_timer_s_start(struct snd_timer * timer)
1158 {
1159 struct snd_timer_system_private *priv;
1160 unsigned long njiff;
1161
1162 priv = (struct snd_timer_system_private *) timer->private_data;
1163 njiff = (priv->last_jiffies = jiffies);
1164 if (priv->correction > timer->sticks - 1) {
1165 priv->correction -= timer->sticks - 1;
1166 njiff++;
1167 } else {
1168 njiff += timer->sticks - priv->correction;
1169 priv->correction = 0;
1170 }
1171 priv->last_expires = njiff;
1172 mod_timer(&priv->tlist, njiff);
1173 return 0;
1174 }
1175
snd_timer_s_stop(struct snd_timer * timer)1176 static int snd_timer_s_stop(struct snd_timer * timer)
1177 {
1178 struct snd_timer_system_private *priv;
1179 unsigned long jiff;
1180
1181 priv = (struct snd_timer_system_private *) timer->private_data;
1182 del_timer(&priv->tlist);
1183 jiff = jiffies;
1184 if (time_before(jiff, priv->last_expires))
1185 timer->sticks = priv->last_expires - jiff;
1186 else
1187 timer->sticks = 1;
1188 priv->correction = 0;
1189 return 0;
1190 }
1191
snd_timer_s_close(struct snd_timer * timer)1192 static int snd_timer_s_close(struct snd_timer *timer)
1193 {
1194 struct snd_timer_system_private *priv;
1195
1196 priv = (struct snd_timer_system_private *)timer->private_data;
1197 del_timer_sync(&priv->tlist);
1198 return 0;
1199 }
1200
1201 static const struct snd_timer_hardware snd_timer_system =
1202 {
1203 .flags = SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_WORK,
1204 .resolution = 1000000000L / HZ,
1205 .ticks = 10000000L,
1206 .close = snd_timer_s_close,
1207 .start = snd_timer_s_start,
1208 .stop = snd_timer_s_stop
1209 };
1210
snd_timer_free_system(struct snd_timer * timer)1211 static void snd_timer_free_system(struct snd_timer *timer)
1212 {
1213 kfree(timer->private_data);
1214 }
1215
snd_timer_register_system(void)1216 static int snd_timer_register_system(void)
1217 {
1218 struct snd_timer *timer;
1219 struct snd_timer_system_private *priv;
1220 int err;
1221
1222 err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1223 if (err < 0)
1224 return err;
1225 strcpy(timer->name, "system timer");
1226 timer->hw = snd_timer_system;
1227 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1228 if (priv == NULL) {
1229 snd_timer_free(timer);
1230 return -ENOMEM;
1231 }
1232 priv->snd_timer = timer;
1233 timer_setup(&priv->tlist, snd_timer_s_function, 0);
1234 timer->private_data = priv;
1235 timer->private_free = snd_timer_free_system;
1236 return snd_timer_global_register(timer);
1237 }
1238
1239 #ifdef CONFIG_SND_PROC_FS
1240 /*
1241 * Info interface
1242 */
1243
snd_timer_proc_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)1244 static void snd_timer_proc_read(struct snd_info_entry *entry,
1245 struct snd_info_buffer *buffer)
1246 {
1247 struct snd_timer *timer;
1248 struct snd_timer_instance *ti;
1249
1250 mutex_lock(®ister_mutex);
1251 list_for_each_entry(timer, &snd_timer_list, device_list) {
1252 if (timer->card && timer->card->shutdown)
1253 continue;
1254 switch (timer->tmr_class) {
1255 case SNDRV_TIMER_CLASS_GLOBAL:
1256 snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1257 break;
1258 case SNDRV_TIMER_CLASS_CARD:
1259 snd_iprintf(buffer, "C%i-%i: ",
1260 timer->card->number, timer->tmr_device);
1261 break;
1262 case SNDRV_TIMER_CLASS_PCM:
1263 snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1264 timer->tmr_device, timer->tmr_subdevice);
1265 break;
1266 default:
1267 snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1268 timer->card ? timer->card->number : -1,
1269 timer->tmr_device, timer->tmr_subdevice);
1270 }
1271 snd_iprintf(buffer, "%s :", timer->name);
1272 if (timer->hw.resolution)
1273 snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1274 timer->hw.resolution / 1000,
1275 timer->hw.resolution % 1000,
1276 timer->hw.ticks);
1277 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1278 snd_iprintf(buffer, " SLAVE");
1279 snd_iprintf(buffer, "\n");
1280 list_for_each_entry(ti, &timer->open_list_head, open_list)
1281 snd_iprintf(buffer, " Client %s : %s\n",
1282 ti->owner ? ti->owner : "unknown",
1283 (ti->flags & (SNDRV_TIMER_IFLG_START |
1284 SNDRV_TIMER_IFLG_RUNNING))
1285 ? "running" : "stopped");
1286 }
1287 mutex_unlock(®ister_mutex);
1288 }
1289
1290 static struct snd_info_entry *snd_timer_proc_entry;
1291
snd_timer_proc_init(void)1292 static void __init snd_timer_proc_init(void)
1293 {
1294 struct snd_info_entry *entry;
1295
1296 entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1297 if (entry != NULL) {
1298 entry->c.text.read = snd_timer_proc_read;
1299 if (snd_info_register(entry) < 0) {
1300 snd_info_free_entry(entry);
1301 entry = NULL;
1302 }
1303 }
1304 snd_timer_proc_entry = entry;
1305 }
1306
snd_timer_proc_done(void)1307 static void __exit snd_timer_proc_done(void)
1308 {
1309 snd_info_free_entry(snd_timer_proc_entry);
1310 }
1311 #else /* !CONFIG_SND_PROC_FS */
1312 #define snd_timer_proc_init()
1313 #define snd_timer_proc_done()
1314 #endif
1315
1316 /*
1317 * USER SPACE interface
1318 */
1319
snd_timer_user_interrupt(struct snd_timer_instance * timeri,unsigned long resolution,unsigned long ticks)1320 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1321 unsigned long resolution,
1322 unsigned long ticks)
1323 {
1324 struct snd_timer_user *tu = timeri->callback_data;
1325 struct snd_timer_read *r;
1326 int prev;
1327
1328 spin_lock(&tu->qlock);
1329 if (tu->qused > 0) {
1330 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1331 r = &tu->queue[prev];
1332 if (r->resolution == resolution) {
1333 r->ticks += ticks;
1334 goto __wake;
1335 }
1336 }
1337 if (tu->qused >= tu->queue_size) {
1338 tu->overrun++;
1339 } else {
1340 r = &tu->queue[tu->qtail++];
1341 tu->qtail %= tu->queue_size;
1342 r->resolution = resolution;
1343 r->ticks = ticks;
1344 tu->qused++;
1345 }
1346 __wake:
1347 spin_unlock(&tu->qlock);
1348 snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1349 wake_up(&tu->qchange_sleep);
1350 }
1351
snd_timer_user_append_to_tqueue(struct snd_timer_user * tu,struct snd_timer_tread64 * tread)1352 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1353 struct snd_timer_tread64 *tread)
1354 {
1355 if (tu->qused >= tu->queue_size) {
1356 tu->overrun++;
1357 } else {
1358 memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1359 tu->qtail %= tu->queue_size;
1360 tu->qused++;
1361 }
1362 }
1363
snd_timer_user_ccallback(struct snd_timer_instance * timeri,int event,struct timespec64 * tstamp,unsigned long resolution)1364 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1365 int event,
1366 struct timespec64 *tstamp,
1367 unsigned long resolution)
1368 {
1369 struct snd_timer_user *tu = timeri->callback_data;
1370 struct snd_timer_tread64 r1;
1371 unsigned long flags;
1372
1373 if (event >= SNDRV_TIMER_EVENT_START &&
1374 event <= SNDRV_TIMER_EVENT_PAUSE)
1375 tu->tstamp = *tstamp;
1376 if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1377 return;
1378 memset(&r1, 0, sizeof(r1));
1379 r1.event = event;
1380 r1.tstamp_sec = tstamp->tv_sec;
1381 r1.tstamp_nsec = tstamp->tv_nsec;
1382 r1.val = resolution;
1383 spin_lock_irqsave(&tu->qlock, flags);
1384 snd_timer_user_append_to_tqueue(tu, &r1);
1385 spin_unlock_irqrestore(&tu->qlock, flags);
1386 snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1387 wake_up(&tu->qchange_sleep);
1388 }
1389
snd_timer_user_disconnect(struct snd_timer_instance * timeri)1390 static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1391 {
1392 struct snd_timer_user *tu = timeri->callback_data;
1393
1394 tu->disconnected = true;
1395 wake_up(&tu->qchange_sleep);
1396 }
1397
snd_timer_user_tinterrupt(struct snd_timer_instance * timeri,unsigned long resolution,unsigned long ticks)1398 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1399 unsigned long resolution,
1400 unsigned long ticks)
1401 {
1402 struct snd_timer_user *tu = timeri->callback_data;
1403 struct snd_timer_tread64 *r, r1;
1404 struct timespec64 tstamp;
1405 int prev, append = 0;
1406
1407 memset(&r1, 0, sizeof(r1));
1408 memset(&tstamp, 0, sizeof(tstamp));
1409 spin_lock(&tu->qlock);
1410 if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1411 (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1412 spin_unlock(&tu->qlock);
1413 return;
1414 }
1415 if (tu->last_resolution != resolution || ticks > 0) {
1416 if (timer_tstamp_monotonic)
1417 ktime_get_ts64(&tstamp);
1418 else
1419 ktime_get_real_ts64(&tstamp);
1420 }
1421 if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1422 tu->last_resolution != resolution) {
1423 r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1424 r1.tstamp_sec = tstamp.tv_sec;
1425 r1.tstamp_nsec = tstamp.tv_nsec;
1426 r1.val = resolution;
1427 snd_timer_user_append_to_tqueue(tu, &r1);
1428 tu->last_resolution = resolution;
1429 append++;
1430 }
1431 if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1432 goto __wake;
1433 if (ticks == 0)
1434 goto __wake;
1435 if (tu->qused > 0) {
1436 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1437 r = &tu->tqueue[prev];
1438 if (r->event == SNDRV_TIMER_EVENT_TICK) {
1439 r->tstamp_sec = tstamp.tv_sec;
1440 r->tstamp_nsec = tstamp.tv_nsec;
1441 r->val += ticks;
1442 append++;
1443 goto __wake;
1444 }
1445 }
1446 r1.event = SNDRV_TIMER_EVENT_TICK;
1447 r1.tstamp_sec = tstamp.tv_sec;
1448 r1.tstamp_nsec = tstamp.tv_nsec;
1449 r1.val = ticks;
1450 snd_timer_user_append_to_tqueue(tu, &r1);
1451 append++;
1452 __wake:
1453 spin_unlock(&tu->qlock);
1454 if (append == 0)
1455 return;
1456 snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1457 wake_up(&tu->qchange_sleep);
1458 }
1459
realloc_user_queue(struct snd_timer_user * tu,int size)1460 static int realloc_user_queue(struct snd_timer_user *tu, int size)
1461 {
1462 struct snd_timer_read *queue = NULL;
1463 struct snd_timer_tread64 *tqueue = NULL;
1464
1465 if (tu->tread) {
1466 tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
1467 if (!tqueue)
1468 return -ENOMEM;
1469 } else {
1470 queue = kcalloc(size, sizeof(*queue), GFP_KERNEL);
1471 if (!queue)
1472 return -ENOMEM;
1473 }
1474
1475 spin_lock_irq(&tu->qlock);
1476 kfree(tu->queue);
1477 kfree(tu->tqueue);
1478 tu->queue_size = size;
1479 tu->queue = queue;
1480 tu->tqueue = tqueue;
1481 tu->qhead = tu->qtail = tu->qused = 0;
1482 spin_unlock_irq(&tu->qlock);
1483
1484 return 0;
1485 }
1486
snd_timer_user_open(struct inode * inode,struct file * file)1487 static int snd_timer_user_open(struct inode *inode, struct file *file)
1488 {
1489 struct snd_timer_user *tu;
1490 int err;
1491
1492 err = stream_open(inode, file);
1493 if (err < 0)
1494 return err;
1495
1496 tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1497 if (tu == NULL)
1498 return -ENOMEM;
1499 spin_lock_init(&tu->qlock);
1500 init_waitqueue_head(&tu->qchange_sleep);
1501 mutex_init(&tu->ioctl_lock);
1502 tu->ticks = 1;
1503 if (realloc_user_queue(tu, 128) < 0) {
1504 kfree(tu);
1505 return -ENOMEM;
1506 }
1507 file->private_data = tu;
1508 return 0;
1509 }
1510
snd_timer_user_release(struct inode * inode,struct file * file)1511 static int snd_timer_user_release(struct inode *inode, struct file *file)
1512 {
1513 struct snd_timer_user *tu;
1514
1515 if (file->private_data) {
1516 tu = file->private_data;
1517 file->private_data = NULL;
1518 mutex_lock(&tu->ioctl_lock);
1519 if (tu->timeri) {
1520 snd_timer_close(tu->timeri);
1521 snd_timer_instance_free(tu->timeri);
1522 }
1523 mutex_unlock(&tu->ioctl_lock);
1524 snd_fasync_free(tu->fasync);
1525 kfree(tu->queue);
1526 kfree(tu->tqueue);
1527 kfree(tu);
1528 }
1529 return 0;
1530 }
1531
snd_timer_user_zero_id(struct snd_timer_id * id)1532 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1533 {
1534 id->dev_class = SNDRV_TIMER_CLASS_NONE;
1535 id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1536 id->card = -1;
1537 id->device = -1;
1538 id->subdevice = -1;
1539 }
1540
snd_timer_user_copy_id(struct snd_timer_id * id,struct snd_timer * timer)1541 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1542 {
1543 id->dev_class = timer->tmr_class;
1544 id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1545 id->card = timer->card ? timer->card->number : -1;
1546 id->device = timer->tmr_device;
1547 id->subdevice = timer->tmr_subdevice;
1548 }
1549
snd_timer_user_next_device(struct snd_timer_id __user * _tid)1550 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1551 {
1552 struct snd_timer_id id;
1553 struct snd_timer *timer;
1554 struct list_head *p;
1555
1556 if (copy_from_user(&id, _tid, sizeof(id)))
1557 return -EFAULT;
1558 mutex_lock(®ister_mutex);
1559 if (id.dev_class < 0) { /* first item */
1560 if (list_empty(&snd_timer_list))
1561 snd_timer_user_zero_id(&id);
1562 else {
1563 timer = list_entry(snd_timer_list.next,
1564 struct snd_timer, device_list);
1565 snd_timer_user_copy_id(&id, timer);
1566 }
1567 } else {
1568 switch (id.dev_class) {
1569 case SNDRV_TIMER_CLASS_GLOBAL:
1570 id.device = id.device < 0 ? 0 : id.device + 1;
1571 list_for_each(p, &snd_timer_list) {
1572 timer = list_entry(p, struct snd_timer, device_list);
1573 if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1574 snd_timer_user_copy_id(&id, timer);
1575 break;
1576 }
1577 if (timer->tmr_device >= id.device) {
1578 snd_timer_user_copy_id(&id, timer);
1579 break;
1580 }
1581 }
1582 if (p == &snd_timer_list)
1583 snd_timer_user_zero_id(&id);
1584 break;
1585 case SNDRV_TIMER_CLASS_CARD:
1586 case SNDRV_TIMER_CLASS_PCM:
1587 if (id.card < 0) {
1588 id.card = 0;
1589 } else {
1590 if (id.device < 0) {
1591 id.device = 0;
1592 } else {
1593 if (id.subdevice < 0)
1594 id.subdevice = 0;
1595 else if (id.subdevice < INT_MAX)
1596 id.subdevice++;
1597 }
1598 }
1599 list_for_each(p, &snd_timer_list) {
1600 timer = list_entry(p, struct snd_timer, device_list);
1601 if (timer->tmr_class > id.dev_class) {
1602 snd_timer_user_copy_id(&id, timer);
1603 break;
1604 }
1605 if (timer->tmr_class < id.dev_class)
1606 continue;
1607 if (timer->card->number > id.card) {
1608 snd_timer_user_copy_id(&id, timer);
1609 break;
1610 }
1611 if (timer->card->number < id.card)
1612 continue;
1613 if (timer->tmr_device > id.device) {
1614 snd_timer_user_copy_id(&id, timer);
1615 break;
1616 }
1617 if (timer->tmr_device < id.device)
1618 continue;
1619 if (timer->tmr_subdevice > id.subdevice) {
1620 snd_timer_user_copy_id(&id, timer);
1621 break;
1622 }
1623 if (timer->tmr_subdevice < id.subdevice)
1624 continue;
1625 snd_timer_user_copy_id(&id, timer);
1626 break;
1627 }
1628 if (p == &snd_timer_list)
1629 snd_timer_user_zero_id(&id);
1630 break;
1631 default:
1632 snd_timer_user_zero_id(&id);
1633 }
1634 }
1635 mutex_unlock(®ister_mutex);
1636 if (copy_to_user(_tid, &id, sizeof(*_tid)))
1637 return -EFAULT;
1638 return 0;
1639 }
1640
snd_timer_user_ginfo(struct file * file,struct snd_timer_ginfo __user * _ginfo)1641 static int snd_timer_user_ginfo(struct file *file,
1642 struct snd_timer_ginfo __user *_ginfo)
1643 {
1644 struct snd_timer_ginfo *ginfo;
1645 struct snd_timer_id tid;
1646 struct snd_timer *t;
1647 struct list_head *p;
1648 int err = 0;
1649
1650 ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1651 if (IS_ERR(ginfo))
1652 return PTR_ERR(ginfo);
1653
1654 tid = ginfo->tid;
1655 memset(ginfo, 0, sizeof(*ginfo));
1656 ginfo->tid = tid;
1657 mutex_lock(®ister_mutex);
1658 t = snd_timer_find(&tid);
1659 if (t != NULL) {
1660 ginfo->card = t->card ? t->card->number : -1;
1661 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1662 ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1663 strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1664 strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1665 ginfo->resolution = t->hw.resolution;
1666 if (t->hw.resolution_min > 0) {
1667 ginfo->resolution_min = t->hw.resolution_min;
1668 ginfo->resolution_max = t->hw.resolution_max;
1669 }
1670 list_for_each(p, &t->open_list_head) {
1671 ginfo->clients++;
1672 }
1673 } else {
1674 err = -ENODEV;
1675 }
1676 mutex_unlock(®ister_mutex);
1677 if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1678 err = -EFAULT;
1679 kfree(ginfo);
1680 return err;
1681 }
1682
timer_set_gparams(struct snd_timer_gparams * gparams)1683 static int timer_set_gparams(struct snd_timer_gparams *gparams)
1684 {
1685 struct snd_timer *t;
1686 int err;
1687
1688 mutex_lock(®ister_mutex);
1689 t = snd_timer_find(&gparams->tid);
1690 if (!t) {
1691 err = -ENODEV;
1692 goto _error;
1693 }
1694 if (!list_empty(&t->open_list_head)) {
1695 err = -EBUSY;
1696 goto _error;
1697 }
1698 if (!t->hw.set_period) {
1699 err = -ENOSYS;
1700 goto _error;
1701 }
1702 err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
1703 _error:
1704 mutex_unlock(®ister_mutex);
1705 return err;
1706 }
1707
snd_timer_user_gparams(struct file * file,struct snd_timer_gparams __user * _gparams)1708 static int snd_timer_user_gparams(struct file *file,
1709 struct snd_timer_gparams __user *_gparams)
1710 {
1711 struct snd_timer_gparams gparams;
1712
1713 if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1714 return -EFAULT;
1715 return timer_set_gparams(&gparams);
1716 }
1717
snd_timer_user_gstatus(struct file * file,struct snd_timer_gstatus __user * _gstatus)1718 static int snd_timer_user_gstatus(struct file *file,
1719 struct snd_timer_gstatus __user *_gstatus)
1720 {
1721 struct snd_timer_gstatus gstatus;
1722 struct snd_timer_id tid;
1723 struct snd_timer *t;
1724 int err = 0;
1725
1726 if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1727 return -EFAULT;
1728 tid = gstatus.tid;
1729 memset(&gstatus, 0, sizeof(gstatus));
1730 gstatus.tid = tid;
1731 mutex_lock(®ister_mutex);
1732 t = snd_timer_find(&tid);
1733 if (t != NULL) {
1734 spin_lock_irq(&t->lock);
1735 gstatus.resolution = snd_timer_hw_resolution(t);
1736 if (t->hw.precise_resolution) {
1737 t->hw.precise_resolution(t, &gstatus.resolution_num,
1738 &gstatus.resolution_den);
1739 } else {
1740 gstatus.resolution_num = gstatus.resolution;
1741 gstatus.resolution_den = 1000000000uL;
1742 }
1743 spin_unlock_irq(&t->lock);
1744 } else {
1745 err = -ENODEV;
1746 }
1747 mutex_unlock(®ister_mutex);
1748 if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1749 err = -EFAULT;
1750 return err;
1751 }
1752
snd_timer_user_tselect(struct file * file,struct snd_timer_select __user * _tselect)1753 static int snd_timer_user_tselect(struct file *file,
1754 struct snd_timer_select __user *_tselect)
1755 {
1756 struct snd_timer_user *tu;
1757 struct snd_timer_select tselect;
1758 char str[32];
1759 int err = 0;
1760
1761 tu = file->private_data;
1762 if (tu->timeri) {
1763 snd_timer_close(tu->timeri);
1764 snd_timer_instance_free(tu->timeri);
1765 tu->timeri = NULL;
1766 }
1767 if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1768 err = -EFAULT;
1769 goto __err;
1770 }
1771 sprintf(str, "application %i", current->pid);
1772 if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1773 tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1774 tu->timeri = snd_timer_instance_new(str);
1775 if (!tu->timeri) {
1776 err = -ENOMEM;
1777 goto __err;
1778 }
1779
1780 tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1781 tu->timeri->callback = tu->tread
1782 ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1783 tu->timeri->ccallback = snd_timer_user_ccallback;
1784 tu->timeri->callback_data = (void *)tu;
1785 tu->timeri->disconnect = snd_timer_user_disconnect;
1786
1787 err = snd_timer_open(tu->timeri, &tselect.id, current->pid);
1788 if (err < 0) {
1789 snd_timer_instance_free(tu->timeri);
1790 tu->timeri = NULL;
1791 }
1792
1793 __err:
1794 return err;
1795 }
1796
snd_timer_user_info(struct file * file,struct snd_timer_info __user * _info)1797 static int snd_timer_user_info(struct file *file,
1798 struct snd_timer_info __user *_info)
1799 {
1800 struct snd_timer_user *tu;
1801 struct snd_timer_info *info;
1802 struct snd_timer *t;
1803 int err = 0;
1804
1805 tu = file->private_data;
1806 if (!tu->timeri)
1807 return -EBADFD;
1808 t = tu->timeri->timer;
1809 if (!t)
1810 return -EBADFD;
1811
1812 info = kzalloc(sizeof(*info), GFP_KERNEL);
1813 if (! info)
1814 return -ENOMEM;
1815 info->card = t->card ? t->card->number : -1;
1816 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1817 info->flags |= SNDRV_TIMER_FLG_SLAVE;
1818 strlcpy(info->id, t->id, sizeof(info->id));
1819 strlcpy(info->name, t->name, sizeof(info->name));
1820 info->resolution = t->hw.resolution;
1821 if (copy_to_user(_info, info, sizeof(*_info)))
1822 err = -EFAULT;
1823 kfree(info);
1824 return err;
1825 }
1826
snd_timer_user_params(struct file * file,struct snd_timer_params __user * _params)1827 static int snd_timer_user_params(struct file *file,
1828 struct snd_timer_params __user *_params)
1829 {
1830 struct snd_timer_user *tu;
1831 struct snd_timer_params params;
1832 struct snd_timer *t;
1833 int err;
1834
1835 tu = file->private_data;
1836 if (!tu->timeri)
1837 return -EBADFD;
1838 t = tu->timeri->timer;
1839 if (!t)
1840 return -EBADFD;
1841 if (copy_from_user(¶ms, _params, sizeof(params)))
1842 return -EFAULT;
1843 if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
1844 u64 resolution;
1845
1846 if (params.ticks < 1) {
1847 err = -EINVAL;
1848 goto _end;
1849 }
1850
1851 /* Don't allow resolution less than 1ms */
1852 resolution = snd_timer_resolution(tu->timeri);
1853 resolution *= params.ticks;
1854 if (resolution < 1000000) {
1855 err = -EINVAL;
1856 goto _end;
1857 }
1858 }
1859 if (params.queue_size > 0 &&
1860 (params.queue_size < 32 || params.queue_size > 1024)) {
1861 err = -EINVAL;
1862 goto _end;
1863 }
1864 if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1865 (1<<SNDRV_TIMER_EVENT_TICK)|
1866 (1<<SNDRV_TIMER_EVENT_START)|
1867 (1<<SNDRV_TIMER_EVENT_STOP)|
1868 (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1869 (1<<SNDRV_TIMER_EVENT_PAUSE)|
1870 (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1871 (1<<SNDRV_TIMER_EVENT_RESUME)|
1872 (1<<SNDRV_TIMER_EVENT_MSTART)|
1873 (1<<SNDRV_TIMER_EVENT_MSTOP)|
1874 (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1875 (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1876 (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1877 (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1878 err = -EINVAL;
1879 goto _end;
1880 }
1881 snd_timer_stop(tu->timeri);
1882 spin_lock_irq(&t->lock);
1883 tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1884 SNDRV_TIMER_IFLG_EXCLUSIVE|
1885 SNDRV_TIMER_IFLG_EARLY_EVENT);
1886 if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1887 tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1888 if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1889 tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1890 if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1891 tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1892 spin_unlock_irq(&t->lock);
1893 if (params.queue_size > 0 &&
1894 (unsigned int)tu->queue_size != params.queue_size) {
1895 err = realloc_user_queue(tu, params.queue_size);
1896 if (err < 0)
1897 goto _end;
1898 }
1899 spin_lock_irq(&tu->qlock);
1900 tu->qhead = tu->qtail = tu->qused = 0;
1901 if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1902 if (tu->tread) {
1903 struct snd_timer_tread64 tread;
1904 memset(&tread, 0, sizeof(tread));
1905 tread.event = SNDRV_TIMER_EVENT_EARLY;
1906 tread.tstamp_sec = 0;
1907 tread.tstamp_nsec = 0;
1908 tread.val = 0;
1909 snd_timer_user_append_to_tqueue(tu, &tread);
1910 } else {
1911 struct snd_timer_read *r = &tu->queue[0];
1912 r->resolution = 0;
1913 r->ticks = 0;
1914 tu->qused++;
1915 tu->qtail++;
1916 }
1917 }
1918 tu->filter = params.filter;
1919 tu->ticks = params.ticks;
1920 spin_unlock_irq(&tu->qlock);
1921 err = 0;
1922 _end:
1923 if (copy_to_user(_params, ¶ms, sizeof(params)))
1924 return -EFAULT;
1925 return err;
1926 }
1927
snd_timer_user_status32(struct file * file,struct snd_timer_status32 __user * _status)1928 static int snd_timer_user_status32(struct file *file,
1929 struct snd_timer_status32 __user *_status)
1930 {
1931 struct snd_timer_user *tu;
1932 struct snd_timer_status32 status;
1933
1934 tu = file->private_data;
1935 if (!tu->timeri)
1936 return -EBADFD;
1937 memset(&status, 0, sizeof(status));
1938 status.tstamp_sec = tu->tstamp.tv_sec;
1939 status.tstamp_nsec = tu->tstamp.tv_nsec;
1940 status.resolution = snd_timer_resolution(tu->timeri);
1941 status.lost = tu->timeri->lost;
1942 status.overrun = tu->overrun;
1943 spin_lock_irq(&tu->qlock);
1944 status.queue = tu->qused;
1945 spin_unlock_irq(&tu->qlock);
1946 if (copy_to_user(_status, &status, sizeof(status)))
1947 return -EFAULT;
1948 return 0;
1949 }
1950
snd_timer_user_status64(struct file * file,struct snd_timer_status64 __user * _status)1951 static int snd_timer_user_status64(struct file *file,
1952 struct snd_timer_status64 __user *_status)
1953 {
1954 struct snd_timer_user *tu;
1955 struct snd_timer_status64 status;
1956
1957 tu = file->private_data;
1958 if (!tu->timeri)
1959 return -EBADFD;
1960 memset(&status, 0, sizeof(status));
1961 status.tstamp_sec = tu->tstamp.tv_sec;
1962 status.tstamp_nsec = tu->tstamp.tv_nsec;
1963 status.resolution = snd_timer_resolution(tu->timeri);
1964 status.lost = tu->timeri->lost;
1965 status.overrun = tu->overrun;
1966 spin_lock_irq(&tu->qlock);
1967 status.queue = tu->qused;
1968 spin_unlock_irq(&tu->qlock);
1969 if (copy_to_user(_status, &status, sizeof(status)))
1970 return -EFAULT;
1971 return 0;
1972 }
1973
snd_timer_user_start(struct file * file)1974 static int snd_timer_user_start(struct file *file)
1975 {
1976 int err;
1977 struct snd_timer_user *tu;
1978
1979 tu = file->private_data;
1980 if (!tu->timeri)
1981 return -EBADFD;
1982 snd_timer_stop(tu->timeri);
1983 tu->timeri->lost = 0;
1984 tu->last_resolution = 0;
1985 err = snd_timer_start(tu->timeri, tu->ticks);
1986 if (err < 0)
1987 return err;
1988 return 0;
1989 }
1990
snd_timer_user_stop(struct file * file)1991 static int snd_timer_user_stop(struct file *file)
1992 {
1993 int err;
1994 struct snd_timer_user *tu;
1995
1996 tu = file->private_data;
1997 if (!tu->timeri)
1998 return -EBADFD;
1999 err = snd_timer_stop(tu->timeri);
2000 if (err < 0)
2001 return err;
2002 return 0;
2003 }
2004
snd_timer_user_continue(struct file * file)2005 static int snd_timer_user_continue(struct file *file)
2006 {
2007 int err;
2008 struct snd_timer_user *tu;
2009
2010 tu = file->private_data;
2011 if (!tu->timeri)
2012 return -EBADFD;
2013 /* start timer instead of continue if it's not used before */
2014 if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
2015 return snd_timer_user_start(file);
2016 tu->timeri->lost = 0;
2017 err = snd_timer_continue(tu->timeri);
2018 if (err < 0)
2019 return err;
2020 return 0;
2021 }
2022
snd_timer_user_pause(struct file * file)2023 static int snd_timer_user_pause(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 err = snd_timer_pause(tu->timeri);
2032 if (err < 0)
2033 return err;
2034 return 0;
2035 }
2036
snd_timer_user_tread(void __user * argp,struct snd_timer_user * tu,unsigned int cmd,bool compat)2037 static int snd_timer_user_tread(void __user *argp, struct snd_timer_user *tu,
2038 unsigned int cmd, bool compat)
2039 {
2040 int __user *p = argp;
2041 int xarg, old_tread;
2042
2043 if (tu->timeri) /* too late */
2044 return -EBUSY;
2045 if (get_user(xarg, p))
2046 return -EFAULT;
2047
2048 old_tread = tu->tread;
2049
2050 if (!xarg)
2051 tu->tread = TREAD_FORMAT_NONE;
2052 else if (cmd == SNDRV_TIMER_IOCTL_TREAD64 ||
2053 (IS_ENABLED(CONFIG_64BIT) && !compat))
2054 tu->tread = TREAD_FORMAT_TIME64;
2055 else
2056 tu->tread = TREAD_FORMAT_TIME32;
2057
2058 if (tu->tread != old_tread &&
2059 realloc_user_queue(tu, tu->queue_size) < 0) {
2060 tu->tread = old_tread;
2061 return -ENOMEM;
2062 }
2063
2064 return 0;
2065 }
2066
2067 enum {
2068 SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
2069 SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
2070 SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
2071 SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
2072 };
2073
__snd_timer_user_ioctl(struct file * file,unsigned int cmd,unsigned long arg,bool compat)2074 static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2075 unsigned long arg, bool compat)
2076 {
2077 struct snd_timer_user *tu;
2078 void __user *argp = (void __user *)arg;
2079 int __user *p = argp;
2080
2081 tu = file->private_data;
2082 switch (cmd) {
2083 case SNDRV_TIMER_IOCTL_PVERSION:
2084 return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
2085 case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
2086 return snd_timer_user_next_device(argp);
2087 case SNDRV_TIMER_IOCTL_TREAD_OLD:
2088 case SNDRV_TIMER_IOCTL_TREAD64:
2089 return snd_timer_user_tread(argp, tu, cmd, compat);
2090 case SNDRV_TIMER_IOCTL_GINFO:
2091 return snd_timer_user_ginfo(file, argp);
2092 case SNDRV_TIMER_IOCTL_GPARAMS:
2093 return snd_timer_user_gparams(file, argp);
2094 case SNDRV_TIMER_IOCTL_GSTATUS:
2095 return snd_timer_user_gstatus(file, argp);
2096 case SNDRV_TIMER_IOCTL_SELECT:
2097 return snd_timer_user_tselect(file, argp);
2098 case SNDRV_TIMER_IOCTL_INFO:
2099 return snd_timer_user_info(file, argp);
2100 case SNDRV_TIMER_IOCTL_PARAMS:
2101 return snd_timer_user_params(file, argp);
2102 case SNDRV_TIMER_IOCTL_STATUS32:
2103 return snd_timer_user_status32(file, argp);
2104 case SNDRV_TIMER_IOCTL_STATUS64:
2105 return snd_timer_user_status64(file, argp);
2106 case SNDRV_TIMER_IOCTL_START:
2107 case SNDRV_TIMER_IOCTL_START_OLD:
2108 return snd_timer_user_start(file);
2109 case SNDRV_TIMER_IOCTL_STOP:
2110 case SNDRV_TIMER_IOCTL_STOP_OLD:
2111 return snd_timer_user_stop(file);
2112 case SNDRV_TIMER_IOCTL_CONTINUE:
2113 case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
2114 return snd_timer_user_continue(file);
2115 case SNDRV_TIMER_IOCTL_PAUSE:
2116 case SNDRV_TIMER_IOCTL_PAUSE_OLD:
2117 return snd_timer_user_pause(file);
2118 }
2119 return -ENOTTY;
2120 }
2121
snd_timer_user_ioctl(struct file * file,unsigned int cmd,unsigned long arg)2122 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2123 unsigned long arg)
2124 {
2125 struct snd_timer_user *tu = file->private_data;
2126 long ret;
2127
2128 mutex_lock(&tu->ioctl_lock);
2129 ret = __snd_timer_user_ioctl(file, cmd, arg, false);
2130 mutex_unlock(&tu->ioctl_lock);
2131 return ret;
2132 }
2133
snd_timer_user_fasync(int fd,struct file * file,int on)2134 static int snd_timer_user_fasync(int fd, struct file * file, int on)
2135 {
2136 struct snd_timer_user *tu;
2137
2138 tu = file->private_data;
2139 return snd_fasync_helper(fd, file, on, &tu->fasync);
2140 }
2141
snd_timer_user_read(struct file * file,char __user * buffer,size_t count,loff_t * offset)2142 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
2143 size_t count, loff_t *offset)
2144 {
2145 struct snd_timer_tread64 *tread;
2146 struct snd_timer_tread32 tread32;
2147 struct snd_timer_user *tu;
2148 long result = 0, unit;
2149 int qhead;
2150 int err = 0;
2151
2152 tu = file->private_data;
2153 switch (tu->tread) {
2154 case TREAD_FORMAT_TIME64:
2155 unit = sizeof(struct snd_timer_tread64);
2156 break;
2157 case TREAD_FORMAT_TIME32:
2158 unit = sizeof(struct snd_timer_tread32);
2159 break;
2160 case TREAD_FORMAT_NONE:
2161 unit = sizeof(struct snd_timer_read);
2162 break;
2163 default:
2164 WARN_ONCE(1, "Corrupt snd_timer_user\n");
2165 return -ENOTSUPP;
2166 }
2167
2168 mutex_lock(&tu->ioctl_lock);
2169 spin_lock_irq(&tu->qlock);
2170 while ((long)count - result >= unit) {
2171 while (!tu->qused) {
2172 wait_queue_entry_t wait;
2173
2174 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
2175 err = -EAGAIN;
2176 goto _error;
2177 }
2178
2179 set_current_state(TASK_INTERRUPTIBLE);
2180 init_waitqueue_entry(&wait, current);
2181 add_wait_queue(&tu->qchange_sleep, &wait);
2182
2183 spin_unlock_irq(&tu->qlock);
2184 mutex_unlock(&tu->ioctl_lock);
2185 schedule();
2186 mutex_lock(&tu->ioctl_lock);
2187 spin_lock_irq(&tu->qlock);
2188
2189 remove_wait_queue(&tu->qchange_sleep, &wait);
2190
2191 if (tu->disconnected) {
2192 err = -ENODEV;
2193 goto _error;
2194 }
2195 if (signal_pending(current)) {
2196 err = -ERESTARTSYS;
2197 goto _error;
2198 }
2199 }
2200
2201 qhead = tu->qhead++;
2202 tu->qhead %= tu->queue_size;
2203 tu->qused--;
2204 spin_unlock_irq(&tu->qlock);
2205
2206 tread = &tu->tqueue[qhead];
2207
2208 switch (tu->tread) {
2209 case TREAD_FORMAT_TIME64:
2210 if (copy_to_user(buffer, tread,
2211 sizeof(struct snd_timer_tread64)))
2212 err = -EFAULT;
2213 break;
2214 case TREAD_FORMAT_TIME32:
2215 memset(&tread32, 0, sizeof(tread32));
2216 tread32 = (struct snd_timer_tread32) {
2217 .event = tread->event,
2218 .tstamp_sec = tread->tstamp_sec,
2219 .tstamp_nsec = tread->tstamp_nsec,
2220 .val = tread->val,
2221 };
2222
2223 if (copy_to_user(buffer, &tread32, sizeof(tread32)))
2224 err = -EFAULT;
2225 break;
2226 case TREAD_FORMAT_NONE:
2227 if (copy_to_user(buffer, &tu->queue[qhead],
2228 sizeof(struct snd_timer_read)))
2229 err = -EFAULT;
2230 break;
2231 default:
2232 err = -ENOTSUPP;
2233 break;
2234 }
2235
2236 spin_lock_irq(&tu->qlock);
2237 if (err < 0)
2238 goto _error;
2239 result += unit;
2240 buffer += unit;
2241 }
2242 _error:
2243 spin_unlock_irq(&tu->qlock);
2244 mutex_unlock(&tu->ioctl_lock);
2245 return result > 0 ? result : err;
2246 }
2247
snd_timer_user_poll(struct file * file,poll_table * wait)2248 static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
2249 {
2250 __poll_t mask;
2251 struct snd_timer_user *tu;
2252
2253 tu = file->private_data;
2254
2255 poll_wait(file, &tu->qchange_sleep, wait);
2256
2257 mask = 0;
2258 spin_lock_irq(&tu->qlock);
2259 if (tu->qused)
2260 mask |= EPOLLIN | EPOLLRDNORM;
2261 if (tu->disconnected)
2262 mask |= EPOLLERR;
2263 spin_unlock_irq(&tu->qlock);
2264
2265 return mask;
2266 }
2267
2268 #ifdef CONFIG_COMPAT
2269 #include "timer_compat.c"
2270 #else
2271 #define snd_timer_user_ioctl_compat NULL
2272 #endif
2273
2274 static const struct file_operations snd_timer_f_ops =
2275 {
2276 .owner = THIS_MODULE,
2277 .read = snd_timer_user_read,
2278 .open = snd_timer_user_open,
2279 .release = snd_timer_user_release,
2280 .llseek = no_llseek,
2281 .poll = snd_timer_user_poll,
2282 .unlocked_ioctl = snd_timer_user_ioctl,
2283 .compat_ioctl = snd_timer_user_ioctl_compat,
2284 .fasync = snd_timer_user_fasync,
2285 };
2286
2287 /* unregister the system timer */
snd_timer_free_all(void)2288 static void snd_timer_free_all(void)
2289 {
2290 struct snd_timer *timer, *n;
2291
2292 list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2293 snd_timer_free(timer);
2294 }
2295
2296 static struct device timer_dev;
2297
2298 /*
2299 * ENTRY functions
2300 */
2301
alsa_timer_init(void)2302 static int __init alsa_timer_init(void)
2303 {
2304 int err;
2305
2306 snd_device_initialize(&timer_dev, NULL);
2307 dev_set_name(&timer_dev, "timer");
2308
2309 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2310 snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2311 "system timer");
2312 #endif
2313
2314 err = snd_timer_register_system();
2315 if (err < 0) {
2316 pr_err("ALSA: unable to register system timer (%i)\n", err);
2317 goto put_timer;
2318 }
2319
2320 err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
2321 &snd_timer_f_ops, NULL, &timer_dev);
2322 if (err < 0) {
2323 pr_err("ALSA: unable to register timer device (%i)\n", err);
2324 snd_timer_free_all();
2325 goto put_timer;
2326 }
2327
2328 snd_timer_proc_init();
2329 return 0;
2330
2331 put_timer:
2332 put_device(&timer_dev);
2333 return err;
2334 }
2335
alsa_timer_exit(void)2336 static void __exit alsa_timer_exit(void)
2337 {
2338 snd_unregister_device(&timer_dev);
2339 snd_timer_free_all();
2340 put_device(&timer_dev);
2341 snd_timer_proc_done();
2342 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2343 snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2344 #endif
2345 }
2346
2347 module_init(alsa_timer_init)
2348 module_exit(alsa_timer_exit)
2349