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