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 <linux/anon_inodes.h>
17#include <linux/idr.h>
18#include <sound/core.h>
19#include <sound/timer.h>
20#include <sound/control.h>
21#include <sound/info.h>
22#include <sound/minors.h>
23#include <sound/initval.h>
24#include <linux/kmod.h>
25
26/* internal flags */
27#define SNDRV_TIMER_IFLG_PAUSED 0x00010000
28#define SNDRV_TIMER_IFLG_DEAD 0x00020000
29
30#if IS_ENABLED(CONFIG_SND_HRTIMER)
31#define DEFAULT_TIMER_LIMIT 4
32#else
33#define DEFAULT_TIMER_LIMIT 1
34#endif
35
36static int timer_limit = DEFAULT_TIMER_LIMIT;
37static int timer_tstamp_monotonic = 1;
38MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
39MODULE_DESCRIPTION("ALSA timer interface");
40MODULE_LICENSE("GPL");
41module_param(timer_limit, int, 0444);
42MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
43module_param(timer_tstamp_monotonic, int, 0444);
44MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
45
46MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
47MODULE_ALIAS("devname:snd/timer");
48
49enum timer_tread_format {
50 TREAD_FORMAT_NONE = 0,
51 TREAD_FORMAT_TIME64,
52 TREAD_FORMAT_TIME32,
53};
54
55struct snd_timer_tread32 {
56 int event;
57 s32 tstamp_sec;
58 s32 tstamp_nsec;
59 unsigned int val;
60};
61
62struct snd_timer_tread64 {
63 int event;
64 u8 pad1[4];
65 s64 tstamp_sec;
66 s64 tstamp_nsec;
67 unsigned int val;
68 u8 pad2[4];
69};
70
71struct snd_timer_user {
72 struct snd_timer_instance *timeri;
73 int tread; /* enhanced read with timestamps and events */
74 unsigned long ticks;
75 unsigned long overrun;
76 int qhead;
77 int qtail;
78 int qused;
79 int queue_size;
80 bool disconnected;
81 struct snd_timer_read *queue;
82 struct snd_timer_tread64 *tqueue;
83 spinlock_t qlock;
84 unsigned long last_resolution;
85 unsigned int filter;
86 struct timespec64 tstamp; /* trigger tstamp */
87 wait_queue_head_t qchange_sleep;
88 struct snd_fasync *fasync;
89 struct mutex ioctl_lock;
90};
91
92struct snd_timer_status32 {
93 s32 tstamp_sec; /* Timestamp - last update */
94 s32 tstamp_nsec;
95 unsigned int resolution; /* current period resolution in ns */
96 unsigned int lost; /* counter of master tick lost */
97 unsigned int overrun; /* count of read queue overruns */
98 unsigned int queue; /* used queue size */
99 unsigned char reserved[64]; /* reserved */
100};
101
102#define SNDRV_TIMER_IOCTL_STATUS32 _IOR('T', 0x14, struct snd_timer_status32)
103
104struct snd_timer_status64 {
105 s64 tstamp_sec; /* Timestamp - last update */
106 s64 tstamp_nsec;
107 unsigned int resolution; /* current period resolution in ns */
108 unsigned int lost; /* counter of master tick lost */
109 unsigned int overrun; /* count of read queue overruns */
110 unsigned int queue; /* used queue size */
111 unsigned char reserved[64]; /* reserved */
112};
113
114#ifdef CONFIG_SND_UTIMER
115#define SNDRV_UTIMERS_MAX_COUNT 128
116/* Internal data structure for keeping the state of the userspace-driven timer */
117struct snd_utimer {
118 char *name;
119 struct snd_timer *timer;
120 unsigned int id;
121};
122#endif
123
124#define SNDRV_TIMER_IOCTL_STATUS64 _IOR('T', 0x14, struct snd_timer_status64)
125
126/* list of timers */
127static LIST_HEAD(snd_timer_list);
128
129/* list of slave instances */
130static LIST_HEAD(snd_timer_slave_list);
131
132/* lock for slave active lists */
133static DEFINE_SPINLOCK(slave_active_lock);
134
135#define MAX_SLAVE_INSTANCES 1000
136static int num_slaves;
137
138static DEFINE_MUTEX(register_mutex);
139
140static int snd_timer_free(struct snd_timer *timer);
141static int snd_timer_dev_free(struct snd_device *device);
142static int snd_timer_dev_register(struct snd_device *device);
143static int snd_timer_dev_disconnect(struct snd_device *device);
144
145static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
146
147/*
148 * create a timer instance with the given owner string.
149 */
150struct snd_timer_instance *snd_timer_instance_new(const char *owner)
151{
152 struct snd_timer_instance *timeri;
153
154 timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
155 if (timeri == NULL)
156 return NULL;
157 timeri->owner = kstrdup(s: owner, GFP_KERNEL);
158 if (! timeri->owner) {
159 kfree(objp: timeri);
160 return NULL;
161 }
162 INIT_LIST_HEAD(list: &timeri->open_list);
163 INIT_LIST_HEAD(list: &timeri->active_list);
164 INIT_LIST_HEAD(list: &timeri->ack_list);
165 INIT_LIST_HEAD(list: &timeri->slave_list_head);
166 INIT_LIST_HEAD(list: &timeri->slave_active_head);
167
168 return timeri;
169}
170EXPORT_SYMBOL(snd_timer_instance_new);
171
172void snd_timer_instance_free(struct snd_timer_instance *timeri)
173{
174 if (timeri) {
175 if (timeri->private_free)
176 timeri->private_free(timeri);
177 kfree(objp: timeri->owner);
178 kfree(objp: timeri);
179 }
180}
181EXPORT_SYMBOL(snd_timer_instance_free);
182
183/*
184 * find a timer instance from the given timer id
185 */
186static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
187{
188 struct snd_timer *timer;
189
190 list_for_each_entry(timer, &snd_timer_list, device_list) {
191 if (timer->tmr_class != tid->dev_class)
192 continue;
193 if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
194 timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
195 (timer->card == NULL ||
196 timer->card->number != tid->card))
197 continue;
198 if (timer->tmr_device != tid->device)
199 continue;
200 if (timer->tmr_subdevice != tid->subdevice)
201 continue;
202 return timer;
203 }
204 return NULL;
205}
206
207#ifdef CONFIG_MODULES
208
209static void snd_timer_request(struct snd_timer_id *tid)
210{
211 switch (tid->dev_class) {
212 case SNDRV_TIMER_CLASS_GLOBAL:
213 if (tid->device < timer_limit)
214 request_module("snd-timer-%i", tid->device);
215 break;
216 case SNDRV_TIMER_CLASS_CARD:
217 case SNDRV_TIMER_CLASS_PCM:
218 if (tid->card < snd_ecards_limit)
219 request_module("snd-card-%i", tid->card);
220 break;
221 default:
222 break;
223 }
224}
225
226#endif
227
228/* move the slave if it belongs to the master; return 1 if match */
229static int check_matching_master_slave(struct snd_timer_instance *master,
230 struct snd_timer_instance *slave)
231{
232 if (slave->slave_class != master->slave_class ||
233 slave->slave_id != master->slave_id)
234 return 0;
235 if (master->timer->num_instances >= master->timer->max_instances)
236 return -EBUSY;
237 list_move_tail(list: &slave->open_list, head: &master->slave_list_head);
238 master->timer->num_instances++;
239 guard(spinlock_irq)(l: &slave_active_lock);
240 guard(spinlock)(l: &master->timer->lock);
241 slave->master = master;
242 slave->timer = master->timer;
243 if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
244 list_add_tail(new: &slave->active_list, head: &master->slave_active_head);
245 return 1;
246}
247
248/*
249 * look for a master instance matching with the slave id of the given slave.
250 * when found, relink the open_link of the slave.
251 *
252 * call this with register_mutex down.
253 */
254static int snd_timer_check_slave(struct snd_timer_instance *slave)
255{
256 struct snd_timer *timer;
257 struct snd_timer_instance *master;
258 int err = 0;
259
260 /* FIXME: it's really dumb to look up all entries.. */
261 list_for_each_entry(timer, &snd_timer_list, device_list) {
262 list_for_each_entry(master, &timer->open_list_head, open_list) {
263 err = check_matching_master_slave(master, slave);
264 if (err != 0) /* match found or error */
265 goto out;
266 }
267 }
268 out:
269 return err < 0 ? err : 0;
270}
271
272/*
273 * look for slave instances matching with the slave id of the given master.
274 * when found, relink the open_link of slaves.
275 *
276 * call this with register_mutex down.
277 */
278static int snd_timer_check_master(struct snd_timer_instance *master)
279{
280 struct snd_timer_instance *slave, *tmp;
281 int err = 0;
282
283 /* check all pending slaves */
284 list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
285 err = check_matching_master_slave(master, slave);
286 if (err < 0)
287 break;
288 }
289 return err < 0 ? err : 0;
290}
291
292static void snd_timer_close_locked(struct snd_timer_instance *timeri,
293 struct device **card_devp_to_put);
294
295/*
296 * open a timer instance
297 * when opening a master, the slave id must be here given.
298 */
299int snd_timer_open(struct snd_timer_instance *timeri,
300 struct snd_timer_id *tid,
301 unsigned int slave_id)
302{
303 struct snd_timer *timer;
304 struct device *card_dev_to_put = NULL;
305 int err;
306
307 mutex_lock(lock: &register_mutex);
308 if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
309 /* open a slave instance */
310 if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
311 tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
312 pr_debug("ALSA: timer: invalid slave class %i\n",
313 tid->dev_sclass);
314 err = -EINVAL;
315 goto unlock;
316 }
317 if (num_slaves >= MAX_SLAVE_INSTANCES) {
318 err = -EBUSY;
319 goto unlock;
320 }
321 timeri->slave_class = tid->dev_sclass;
322 timeri->slave_id = tid->device;
323 timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
324 list_add_tail(new: &timeri->open_list, head: &snd_timer_slave_list);
325 num_slaves++;
326 err = snd_timer_check_slave(slave: timeri);
327 goto list_added;
328 }
329
330 /* open a master instance */
331 timer = snd_timer_find(tid);
332#ifdef CONFIG_MODULES
333 if (!timer) {
334 mutex_unlock(lock: &register_mutex);
335 snd_timer_request(tid);
336 mutex_lock(lock: &register_mutex);
337 timer = snd_timer_find(tid);
338 }
339#endif
340 if (!timer) {
341 err = -ENODEV;
342 goto unlock;
343 }
344 if (!list_empty(head: &timer->open_list_head)) {
345 struct snd_timer_instance *t =
346 list_entry(timer->open_list_head.next,
347 struct snd_timer_instance, open_list);
348 if (t->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
349 err = -EBUSY;
350 goto unlock;
351 }
352 }
353 if (timer->num_instances >= timer->max_instances) {
354 err = -EBUSY;
355 goto unlock;
356 }
357 if (!try_module_get(module: timer->module)) {
358 err = -EBUSY;
359 goto unlock;
360 }
361 /* take a card refcount for safe disconnection */
362 if (timer->card) {
363 get_device(dev: &timer->card->card_dev);
364 card_dev_to_put = &timer->card->card_dev;
365 }
366
367 if (list_empty(head: &timer->open_list_head) && timer->hw.open) {
368 err = timer->hw.open(timer);
369 if (err) {
370 module_put(module: timer->module);
371 goto unlock;
372 }
373 }
374
375 timeri->timer = timer;
376 timeri->slave_class = tid->dev_sclass;
377 timeri->slave_id = slave_id;
378
379 list_add_tail(new: &timeri->open_list, head: &timer->open_list_head);
380 timer->num_instances++;
381 err = snd_timer_check_master(master: timeri);
382list_added:
383 if (err < 0)
384 snd_timer_close_locked(timeri, card_devp_to_put: &card_dev_to_put);
385
386 unlock:
387 mutex_unlock(lock: &register_mutex);
388 /* put_device() is called after unlock for avoiding deadlock */
389 if (err < 0 && card_dev_to_put)
390 put_device(dev: card_dev_to_put);
391 return err;
392}
393EXPORT_SYMBOL(snd_timer_open);
394
395/* remove slave links, called from snd_timer_close_locked() below */
396static void remove_slave_links(struct snd_timer_instance *timeri,
397 struct snd_timer *timer)
398{
399 struct snd_timer_instance *slave, *tmp;
400
401 guard(spinlock_irq)(l: &slave_active_lock);
402 guard(spinlock)(l: &timer->lock);
403 timeri->timer = NULL;
404 list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head, open_list) {
405 list_move_tail(list: &slave->open_list, head: &snd_timer_slave_list);
406 timer->num_instances--;
407 slave->master = NULL;
408 slave->timer = NULL;
409 list_del_init(entry: &slave->ack_list);
410 list_del_init(entry: &slave->active_list);
411 }
412}
413
414/*
415 * close a timer instance
416 * call this with register_mutex down.
417 */
418static void snd_timer_close_locked(struct snd_timer_instance *timeri,
419 struct device **card_devp_to_put)
420{
421 struct snd_timer *timer = timeri->timer;
422
423 if (timer) {
424 guard(spinlock_irq)(l: &timer->lock);
425 timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
426 }
427
428 if (!list_empty(head: &timeri->open_list)) {
429 list_del_init(entry: &timeri->open_list);
430 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
431 num_slaves--;
432 }
433
434 /* force to stop the timer */
435 snd_timer_stop(timeri);
436
437 if (timer) {
438 timer->num_instances--;
439 /* wait, until the active callback is finished */
440 spin_lock_irq(lock: &timer->lock);
441 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
442 spin_unlock_irq(lock: &timer->lock);
443 udelay(usec: 10);
444 spin_lock_irq(lock: &timer->lock);
445 }
446 spin_unlock_irq(lock: &timer->lock);
447
448 remove_slave_links(timeri, timer);
449
450 /* slave doesn't need to release timer resources below */
451 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
452 timer = NULL;
453 }
454
455 if (timer) {
456 if (list_empty(head: &timer->open_list_head) && timer->hw.close)
457 timer->hw.close(timer);
458 /* release a card refcount for safe disconnection */
459 if (timer->card)
460 *card_devp_to_put = &timer->card->card_dev;
461 module_put(module: timer->module);
462 }
463}
464
465/*
466 * close a timer instance
467 */
468void snd_timer_close(struct snd_timer_instance *timeri)
469{
470 struct device *card_dev_to_put = NULL;
471
472 if (snd_BUG_ON(!timeri))
473 return;
474
475 scoped_guard(mutex, &register_mutex)
476 snd_timer_close_locked(timeri, card_devp_to_put: &card_dev_to_put);
477 /* put_device() is called after unlock for avoiding deadlock */
478 if (card_dev_to_put)
479 put_device(dev: card_dev_to_put);
480}
481EXPORT_SYMBOL(snd_timer_close);
482
483static unsigned long snd_timer_hw_resolution(struct snd_timer *timer)
484{
485 if (timer->hw.c_resolution)
486 return timer->hw.c_resolution(timer);
487 else
488 return timer->hw.resolution;
489}
490
491unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
492{
493 struct snd_timer * timer;
494 unsigned long ret = 0;
495
496 if (timeri == NULL)
497 return 0;
498 timer = timeri->timer;
499 if (timer) {
500 guard(spinlock_irqsave)(l: &timer->lock);
501 ret = snd_timer_hw_resolution(timer);
502 }
503 return ret;
504}
505EXPORT_SYMBOL(snd_timer_resolution);
506
507static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
508{
509 struct snd_timer *timer = ti->timer;
510 unsigned long resolution = 0;
511 struct snd_timer_instance *ts;
512 struct timespec64 tstamp;
513
514 if (timer_tstamp_monotonic)
515 ktime_get_ts64(ts: &tstamp);
516 else
517 ktime_get_real_ts64(tv: &tstamp);
518 if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
519 event > SNDRV_TIMER_EVENT_PAUSE))
520 return;
521 if (timer &&
522 (event == SNDRV_TIMER_EVENT_START ||
523 event == SNDRV_TIMER_EVENT_CONTINUE))
524 resolution = snd_timer_hw_resolution(timer);
525 if (ti->ccallback)
526 ti->ccallback(ti, event, &tstamp, resolution);
527 if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
528 return;
529 if (timer == NULL)
530 return;
531 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
532 return;
533 event += 10; /* convert to SNDRV_TIMER_EVENT_MXXX */
534 list_for_each_entry(ts, &ti->slave_active_head, active_list)
535 if (ts->ccallback)
536 ts->ccallback(ts, event, &tstamp, resolution);
537}
538
539/* start/continue a master timer */
540static int snd_timer_start1(struct snd_timer_instance *timeri,
541 bool start, unsigned long ticks)
542{
543 struct snd_timer *timer;
544 int result;
545
546 timer = timeri->timer;
547 if (!timer)
548 return -EINVAL;
549
550 guard(spinlock_irqsave)(l: &timer->lock);
551 if (timeri->flags & SNDRV_TIMER_IFLG_DEAD)
552 return -EINVAL;
553 if (timer->card && timer->card->shutdown)
554 return -ENODEV;
555 if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
556 SNDRV_TIMER_IFLG_START))
557 return -EBUSY;
558
559 /* check the actual time for the start tick;
560 * bail out as error if it's way too low (< 100us)
561 */
562 if (start && !(timer->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
563 if ((u64)snd_timer_hw_resolution(timer) * ticks < 100000)
564 return -EINVAL;
565 }
566
567 if (start)
568 timeri->ticks = timeri->cticks = ticks;
569 else if (!timeri->cticks)
570 timeri->cticks = 1;
571 timeri->pticks = 0;
572
573 list_move_tail(list: &timeri->active_list, head: &timer->active_list_head);
574 if (timer->running) {
575 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
576 goto __start_now;
577 timer->flags |= SNDRV_TIMER_FLG_RESCHED;
578 timeri->flags |= SNDRV_TIMER_IFLG_START;
579 result = 1; /* delayed start */
580 } else {
581 if (start)
582 timer->sticks = ticks;
583 timer->hw.start(timer);
584 __start_now:
585 timer->running++;
586 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
587 result = 0;
588 }
589 snd_timer_notify1(ti: timeri, event: start ? SNDRV_TIMER_EVENT_START :
590 SNDRV_TIMER_EVENT_CONTINUE);
591 return result;
592}
593
594/* start/continue a slave timer */
595static int snd_timer_start_slave(struct snd_timer_instance *timeri,
596 bool start)
597{
598 guard(spinlock_irqsave)(l: &slave_active_lock);
599 if (timeri->flags & SNDRV_TIMER_IFLG_DEAD)
600 return -EINVAL;
601 if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING)
602 return -EBUSY;
603 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
604 if (timeri->master && timeri->timer) {
605 guard(spinlock)(l: &timeri->timer->lock);
606 list_add_tail(new: &timeri->active_list,
607 head: &timeri->master->slave_active_head);
608 snd_timer_notify1(ti: timeri, event: start ? SNDRV_TIMER_EVENT_START :
609 SNDRV_TIMER_EVENT_CONTINUE);
610 }
611 return 1; /* delayed start */
612}
613
614/* stop/pause a master timer */
615static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
616{
617 struct snd_timer *timer;
618
619 timer = timeri->timer;
620 if (!timer)
621 return -EINVAL;
622 guard(spinlock_irqsave)(l: &timer->lock);
623 list_del_init(entry: &timeri->ack_list);
624 list_del_init(entry: &timeri->active_list);
625 if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
626 SNDRV_TIMER_IFLG_START)))
627 return -EBUSY;
628 if (timer->card && timer->card->shutdown)
629 return 0;
630 if (stop) {
631 timeri->cticks = timeri->ticks;
632 timeri->pticks = 0;
633 }
634 if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
635 !(--timer->running)) {
636 timer->hw.stop(timer);
637 if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
638 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
639 snd_timer_reschedule(timer, ticks_left: 0);
640 if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
641 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
642 timer->hw.start(timer);
643 }
644 }
645 }
646 timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
647 if (stop)
648 timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
649 else
650 timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
651 snd_timer_notify1(ti: timeri, event: stop ? SNDRV_TIMER_EVENT_STOP :
652 SNDRV_TIMER_EVENT_PAUSE);
653 return 0;
654}
655
656/* stop/pause a slave timer */
657static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
658{
659 bool running;
660
661 guard(spinlock_irqsave)(l: &slave_active_lock);
662 running = timeri->flags & SNDRV_TIMER_IFLG_RUNNING;
663 timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
664 if (timeri->timer) {
665 guard(spinlock)(l: &timeri->timer->lock);
666 list_del_init(entry: &timeri->ack_list);
667 list_del_init(entry: &timeri->active_list);
668 if (running)
669 snd_timer_notify1(ti: timeri, event: stop ? SNDRV_TIMER_EVENT_STOP :
670 SNDRV_TIMER_EVENT_PAUSE);
671 }
672 return running ? 0 : -EBUSY;
673}
674
675/*
676 * start the timer instance
677 */
678int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
679{
680 if (timeri == NULL || ticks < 1)
681 return -EINVAL;
682 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
683 return snd_timer_start_slave(timeri, start: true);
684 else
685 return snd_timer_start1(timeri, start: true, ticks);
686}
687EXPORT_SYMBOL(snd_timer_start);
688
689/*
690 * stop the timer instance.
691 *
692 * do not call this from the timer callback!
693 */
694int snd_timer_stop(struct snd_timer_instance *timeri)
695{
696 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
697 return snd_timer_stop_slave(timeri, stop: true);
698 else
699 return snd_timer_stop1(timeri, stop: true);
700}
701EXPORT_SYMBOL(snd_timer_stop);
702
703/*
704 * start again.. the tick is kept.
705 */
706int snd_timer_continue(struct snd_timer_instance *timeri)
707{
708 /* timer can continue only after pause */
709 if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
710 return -EINVAL;
711
712 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
713 return snd_timer_start_slave(timeri, start: false);
714 else
715 return snd_timer_start1(timeri, start: false, ticks: 0);
716}
717EXPORT_SYMBOL(snd_timer_continue);
718
719/*
720 * pause.. remember the ticks left
721 */
722int snd_timer_pause(struct snd_timer_instance * timeri)
723{
724 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
725 return snd_timer_stop_slave(timeri, stop: false);
726 else
727 return snd_timer_stop1(timeri, stop: false);
728}
729EXPORT_SYMBOL(snd_timer_pause);
730
731/*
732 * reschedule the timer
733 *
734 * start pending instances and check the scheduling ticks.
735 * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
736 */
737static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
738{
739 struct snd_timer_instance *ti;
740 unsigned long ticks = ~0UL;
741
742 list_for_each_entry(ti, &timer->active_list_head, active_list) {
743 if (ti->flags & SNDRV_TIMER_IFLG_START) {
744 ti->flags &= ~SNDRV_TIMER_IFLG_START;
745 ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
746 timer->running++;
747 }
748 if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
749 if (ticks > ti->cticks)
750 ticks = ti->cticks;
751 }
752 }
753 if (ticks == ~0UL) {
754 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
755 return;
756 }
757 if (ticks > timer->hw.ticks)
758 ticks = timer->hw.ticks;
759 if (ticks_left != ticks)
760 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
761 timer->sticks = ticks;
762}
763
764/* call callbacks in timer ack list */
765static void snd_timer_process_callbacks(struct snd_timer *timer,
766 struct list_head *head)
767{
768 struct snd_timer_instance *ti;
769 unsigned long resolution, ticks;
770
771 while (!list_empty(head)) {
772 ti = list_first_entry(head, struct snd_timer_instance,
773 ack_list);
774
775 /* remove from ack_list and make empty */
776 list_del_init(entry: &ti->ack_list);
777
778 if (!(ti->flags & SNDRV_TIMER_IFLG_DEAD)) {
779 ticks = ti->pticks;
780 ti->pticks = 0;
781 resolution = ti->resolution;
782 ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
783 spin_unlock(lock: &timer->lock);
784 if (ti->callback)
785 ti->callback(ti, resolution, ticks);
786 spin_lock(lock: &timer->lock);
787 ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
788 }
789 }
790}
791
792/* clear pending instances from ack list */
793static void snd_timer_clear_callbacks(struct snd_timer *timer,
794 struct list_head *head)
795{
796 guard(spinlock_irqsave)(l: &timer->lock);
797 while (!list_empty(head))
798 list_del_init(entry: head->next);
799}
800
801/*
802 * timer work
803 *
804 */
805static void snd_timer_work(struct work_struct *work)
806{
807 struct snd_timer *timer = container_of(work, struct snd_timer, task_work);
808
809 if (timer->card && timer->card->shutdown) {
810 snd_timer_clear_callbacks(timer, head: &timer->sack_list_head);
811 return;
812 }
813
814 guard(spinlock_irqsave)(l: &timer->lock);
815 snd_timer_process_callbacks(timer, head: &timer->sack_list_head);
816}
817
818/*
819 * timer interrupt
820 *
821 * ticks_left is usually equal to timer->sticks.
822 *
823 */
824void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
825{
826 struct snd_timer_instance *ti, *ts, *tmp;
827 unsigned long resolution;
828 struct list_head *ack_list_head;
829
830 if (timer == NULL)
831 return;
832
833 if (timer->card && timer->card->shutdown) {
834 snd_timer_clear_callbacks(timer, head: &timer->ack_list_head);
835 return;
836 }
837
838 guard(spinlock_irqsave)(l: &timer->lock);
839
840 /* remember the current resolution */
841 resolution = snd_timer_hw_resolution(timer);
842
843 /* loop for all active instances
844 * Here we cannot use list_for_each_entry because the active_list of a
845 * processed instance is relinked to done_list_head before the callback
846 * is called.
847 */
848 list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
849 active_list) {
850 if (ti->flags & SNDRV_TIMER_IFLG_DEAD)
851 continue;
852 if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
853 continue;
854 ti->pticks += ticks_left;
855 ti->resolution = resolution;
856 if (ti->cticks < ticks_left)
857 ti->cticks = 0;
858 else
859 ti->cticks -= ticks_left;
860 if (ti->cticks) /* not expired */
861 continue;
862 if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
863 ti->cticks = ti->ticks;
864 } else {
865 ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
866 --timer->running;
867 list_del_init(entry: &ti->active_list);
868 }
869 if ((timer->hw.flags & SNDRV_TIMER_HW_WORK) ||
870 (ti->flags & SNDRV_TIMER_IFLG_FAST))
871 ack_list_head = &timer->ack_list_head;
872 else
873 ack_list_head = &timer->sack_list_head;
874 if (list_empty(head: &ti->ack_list))
875 list_add_tail(new: &ti->ack_list, head: ack_list_head);
876 list_for_each_entry(ts, &ti->slave_active_head, active_list) {
877 ts->pticks = ti->pticks;
878 ts->resolution = resolution;
879 if (list_empty(head: &ts->ack_list))
880 list_add_tail(new: &ts->ack_list, head: ack_list_head);
881 }
882 }
883 if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
884 snd_timer_reschedule(timer, ticks_left: timer->sticks);
885 if (timer->running) {
886 if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
887 timer->hw.stop(timer);
888 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
889 }
890 if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
891 (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
892 /* restart timer */
893 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
894 timer->hw.start(timer);
895 }
896 } else {
897 timer->hw.stop(timer);
898 }
899
900 /* now process all fast callbacks */
901 snd_timer_process_callbacks(timer, head: &timer->ack_list_head);
902
903 /* do we have any slow callbacks? */
904 if (!list_empty(head: &timer->sack_list_head))
905 queue_work(wq: system_highpri_wq, work: &timer->task_work);
906}
907EXPORT_SYMBOL(snd_timer_interrupt);
908
909/*
910
911 */
912
913int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
914 struct snd_timer **rtimer)
915{
916 struct snd_timer *timer;
917 int err;
918 static const struct snd_device_ops ops = {
919 .dev_free = snd_timer_dev_free,
920 .dev_register = snd_timer_dev_register,
921 .dev_disconnect = snd_timer_dev_disconnect,
922 };
923
924 if (snd_BUG_ON(!tid))
925 return -EINVAL;
926 if (tid->dev_class == SNDRV_TIMER_CLASS_CARD ||
927 tid->dev_class == SNDRV_TIMER_CLASS_PCM) {
928 if (WARN_ON(!card))
929 return -EINVAL;
930 }
931 if (rtimer)
932 *rtimer = NULL;
933 timer = kzalloc(sizeof(*timer), GFP_KERNEL);
934 if (!timer)
935 return -ENOMEM;
936 timer->tmr_class = tid->dev_class;
937 timer->card = card;
938 timer->tmr_device = tid->device;
939 timer->tmr_subdevice = tid->subdevice;
940 if (id)
941 strscpy(timer->id, id, sizeof(timer->id));
942 timer->sticks = 1;
943 INIT_LIST_HEAD(list: &timer->device_list);
944 INIT_LIST_HEAD(list: &timer->open_list_head);
945 INIT_LIST_HEAD(list: &timer->active_list_head);
946 INIT_LIST_HEAD(list: &timer->ack_list_head);
947 INIT_LIST_HEAD(list: &timer->sack_list_head);
948 spin_lock_init(&timer->lock);
949 INIT_WORK(&timer->task_work, snd_timer_work);
950 timer->max_instances = 1000; /* default limit per timer */
951 if (card != NULL) {
952 timer->module = card->module;
953 err = snd_device_new(card, type: SNDRV_DEV_TIMER, device_data: timer, ops: &ops);
954 if (err < 0) {
955 snd_timer_free(timer);
956 return err;
957 }
958 }
959 if (rtimer)
960 *rtimer = timer;
961 return 0;
962}
963EXPORT_SYMBOL(snd_timer_new);
964
965static int snd_timer_free(struct snd_timer *timer)
966{
967 if (!timer)
968 return 0;
969
970 guard(mutex)(T: &register_mutex);
971 if (! list_empty(head: &timer->open_list_head)) {
972 struct list_head *p, *n;
973 struct snd_timer_instance *ti;
974 pr_warn("ALSA: timer %p is busy?\n", timer);
975 list_for_each_safe(p, n, &timer->open_list_head) {
976 list_del_init(entry: p);
977 ti = list_entry(p, struct snd_timer_instance, open_list);
978 ti->timer = NULL;
979 }
980 }
981 list_del(entry: &timer->device_list);
982
983 if (timer->private_free)
984 timer->private_free(timer);
985 kfree(objp: timer);
986 return 0;
987}
988
989static int snd_timer_dev_free(struct snd_device *device)
990{
991 struct snd_timer *timer = device->device_data;
992 return snd_timer_free(timer);
993}
994
995static int snd_timer_dev_register(struct snd_device *dev)
996{
997 struct snd_timer *timer = dev->device_data;
998 struct snd_timer *timer1;
999
1000 if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
1001 return -ENXIO;
1002 if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
1003 !timer->hw.resolution && timer->hw.c_resolution == NULL)
1004 return -EINVAL;
1005
1006 guard(mutex)(T: &register_mutex);
1007 list_for_each_entry(timer1, &snd_timer_list, device_list) {
1008 if (timer1->tmr_class > timer->tmr_class)
1009 break;
1010 if (timer1->tmr_class < timer->tmr_class)
1011 continue;
1012 if (timer1->card && timer->card) {
1013 if (timer1->card->number > timer->card->number)
1014 break;
1015 if (timer1->card->number < timer->card->number)
1016 continue;
1017 }
1018 if (timer1->tmr_device > timer->tmr_device)
1019 break;
1020 if (timer1->tmr_device < timer->tmr_device)
1021 continue;
1022 if (timer1->tmr_subdevice > timer->tmr_subdevice)
1023 break;
1024 if (timer1->tmr_subdevice < timer->tmr_subdevice)
1025 continue;
1026 /* conflicts.. */
1027 return -EBUSY;
1028 }
1029 list_add_tail(new: &timer->device_list, head: &timer1->device_list);
1030 return 0;
1031}
1032
1033static int snd_timer_dev_disconnect(struct snd_device *device)
1034{
1035 struct snd_timer *timer = device->device_data;
1036 struct snd_timer_instance *ti;
1037
1038 guard(mutex)(T: &register_mutex);
1039 list_del_init(entry: &timer->device_list);
1040 /* wake up pending sleepers */
1041 list_for_each_entry(ti, &timer->open_list_head, open_list) {
1042 if (ti->disconnect)
1043 ti->disconnect(ti);
1044 }
1045 return 0;
1046}
1047
1048void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp)
1049{
1050 unsigned long resolution = 0;
1051 struct snd_timer_instance *ti, *ts;
1052
1053 if (timer->card && timer->card->shutdown)
1054 return;
1055 if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
1056 return;
1057 if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
1058 event > SNDRV_TIMER_EVENT_MRESUME))
1059 return;
1060 guard(spinlock_irqsave)(l: &timer->lock);
1061 if (event == SNDRV_TIMER_EVENT_MSTART ||
1062 event == SNDRV_TIMER_EVENT_MCONTINUE ||
1063 event == SNDRV_TIMER_EVENT_MRESUME)
1064 resolution = snd_timer_hw_resolution(timer);
1065 list_for_each_entry(ti, &timer->active_list_head, active_list) {
1066 if (ti->ccallback)
1067 ti->ccallback(ti, event, tstamp, resolution);
1068 list_for_each_entry(ts, &ti->slave_active_head, active_list)
1069 if (ts->ccallback)
1070 ts->ccallback(ts, event, tstamp, resolution);
1071 }
1072}
1073EXPORT_SYMBOL(snd_timer_notify);
1074
1075/*
1076 * exported functions for global timers
1077 */
1078int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
1079{
1080 struct snd_timer_id tid;
1081
1082 tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
1083 tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1084 tid.card = -1;
1085 tid.device = device;
1086 tid.subdevice = 0;
1087 return snd_timer_new(NULL, id, &tid, rtimer);
1088}
1089EXPORT_SYMBOL(snd_timer_global_new);
1090
1091int snd_timer_global_free(struct snd_timer *timer)
1092{
1093 return snd_timer_free(timer);
1094}
1095EXPORT_SYMBOL(snd_timer_global_free);
1096
1097int snd_timer_global_register(struct snd_timer *timer)
1098{
1099 struct snd_device dev;
1100
1101 memset(s: &dev, c: 0, n: sizeof(dev));
1102 dev.device_data = timer;
1103 return snd_timer_dev_register(dev: &dev);
1104}
1105EXPORT_SYMBOL(snd_timer_global_register);
1106
1107/*
1108 * System timer
1109 */
1110
1111struct snd_timer_system_private {
1112 struct timer_list tlist;
1113 struct snd_timer *snd_timer;
1114 unsigned long last_expires;
1115 unsigned long last_jiffies;
1116 unsigned long correction;
1117};
1118
1119static void snd_timer_s_function(struct timer_list *t)
1120{
1121 struct snd_timer_system_private *priv = timer_container_of(priv, t,
1122 tlist);
1123 struct snd_timer *timer = priv->snd_timer;
1124 unsigned long jiff = jiffies;
1125 if (time_after(jiff, priv->last_expires))
1126 priv->correction += (long)jiff - (long)priv->last_expires;
1127 snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
1128}
1129
1130static int snd_timer_s_start(struct snd_timer * timer)
1131{
1132 struct snd_timer_system_private *priv;
1133 unsigned long njiff;
1134
1135 priv = (struct snd_timer_system_private *) timer->private_data;
1136 njiff = (priv->last_jiffies = jiffies);
1137 if (priv->correction > timer->sticks - 1) {
1138 priv->correction -= timer->sticks - 1;
1139 njiff++;
1140 } else {
1141 njiff += timer->sticks - priv->correction;
1142 priv->correction = 0;
1143 }
1144 priv->last_expires = njiff;
1145 mod_timer(timer: &priv->tlist, expires: njiff);
1146 return 0;
1147}
1148
1149static int snd_timer_s_stop(struct snd_timer * timer)
1150{
1151 struct snd_timer_system_private *priv;
1152 unsigned long jiff;
1153
1154 priv = (struct snd_timer_system_private *) timer->private_data;
1155 timer_delete(timer: &priv->tlist);
1156 jiff = jiffies;
1157 if (time_before(jiff, priv->last_expires))
1158 timer->sticks = priv->last_expires - jiff;
1159 else
1160 timer->sticks = 1;
1161 priv->correction = 0;
1162 return 0;
1163}
1164
1165static int snd_timer_s_close(struct snd_timer *timer)
1166{
1167 struct snd_timer_system_private *priv;
1168
1169 priv = (struct snd_timer_system_private *)timer->private_data;
1170 timer_delete_sync(timer: &priv->tlist);
1171 return 0;
1172}
1173
1174static const struct snd_timer_hardware snd_timer_system =
1175{
1176 .flags = SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_WORK,
1177 .resolution = NSEC_PER_SEC / HZ,
1178 .ticks = 10000000L,
1179 .close = snd_timer_s_close,
1180 .start = snd_timer_s_start,
1181 .stop = snd_timer_s_stop
1182};
1183
1184static void snd_timer_free_system(struct snd_timer *timer)
1185{
1186 kfree(objp: timer->private_data);
1187}
1188
1189static int snd_timer_register_system(void)
1190{
1191 struct snd_timer *timer;
1192 struct snd_timer_system_private *priv;
1193 int err;
1194
1195 err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1196 if (err < 0)
1197 return err;
1198 strscpy(timer->name, "system timer");
1199 timer->hw = snd_timer_system;
1200 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1201 if (priv == NULL) {
1202 snd_timer_free(timer);
1203 return -ENOMEM;
1204 }
1205 priv->snd_timer = timer;
1206 timer_setup(&priv->tlist, snd_timer_s_function, 0);
1207 timer->private_data = priv;
1208 timer->private_free = snd_timer_free_system;
1209 return snd_timer_global_register(timer);
1210}
1211
1212#ifdef CONFIG_SND_PROC_FS
1213/*
1214 * Info interface
1215 */
1216
1217static void snd_timer_proc_read(struct snd_info_entry *entry,
1218 struct snd_info_buffer *buffer)
1219{
1220 struct snd_timer *timer;
1221 struct snd_timer_instance *ti;
1222 unsigned long resolution;
1223
1224 guard(mutex)(T: &register_mutex);
1225 list_for_each_entry(timer, &snd_timer_list, device_list) {
1226 if (timer->card && timer->card->shutdown)
1227 continue;
1228 switch (timer->tmr_class) {
1229 case SNDRV_TIMER_CLASS_GLOBAL:
1230 snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1231 break;
1232 case SNDRV_TIMER_CLASS_CARD:
1233 snd_iprintf(buffer, "C%i-%i: ",
1234 timer->card->number, timer->tmr_device);
1235 break;
1236 case SNDRV_TIMER_CLASS_PCM:
1237 snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1238 timer->tmr_device, timer->tmr_subdevice);
1239 break;
1240 default:
1241 snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1242 timer->card ? timer->card->number : -1,
1243 timer->tmr_device, timer->tmr_subdevice);
1244 }
1245 snd_iprintf(buffer, "%s :", timer->name);
1246 scoped_guard(spinlock_irq, &timer->lock)
1247 resolution = snd_timer_hw_resolution(timer);
1248 if (resolution)
1249 snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1250 resolution / 1000,
1251 resolution % 1000,
1252 timer->hw.ticks);
1253 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1254 snd_iprintf(buffer, " SLAVE");
1255 snd_iprintf(buffer, "\n");
1256 list_for_each_entry(ti, &timer->open_list_head, open_list)
1257 snd_iprintf(buffer, " Client %s : %s\n",
1258 ti->owner ? ti->owner : "unknown",
1259 (ti->flags & (SNDRV_TIMER_IFLG_START |
1260 SNDRV_TIMER_IFLG_RUNNING))
1261 ? "running" : "stopped");
1262 }
1263}
1264
1265static struct snd_info_entry *snd_timer_proc_entry;
1266
1267static void __init snd_timer_proc_init(void)
1268{
1269 struct snd_info_entry *entry;
1270
1271 entry = snd_info_create_module_entry(THIS_MODULE, name: "timers", NULL);
1272 if (entry != NULL) {
1273 entry->c.text.read = snd_timer_proc_read;
1274 if (snd_info_register(entry) < 0) {
1275 snd_info_free_entry(entry);
1276 entry = NULL;
1277 }
1278 }
1279 snd_timer_proc_entry = entry;
1280}
1281
1282static void __exit snd_timer_proc_done(void)
1283{
1284 snd_info_free_entry(entry: snd_timer_proc_entry);
1285}
1286#else /* !CONFIG_SND_PROC_FS */
1287#define snd_timer_proc_init()
1288#define snd_timer_proc_done()
1289#endif
1290
1291/*
1292 * USER SPACE interface
1293 */
1294
1295static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1296 unsigned long resolution,
1297 unsigned long ticks)
1298{
1299 struct snd_timer_user *tu = timeri->callback_data;
1300 struct snd_timer_read *r;
1301 int prev;
1302
1303 guard(spinlock)(l: &tu->qlock);
1304 if (tu->qused > 0) {
1305 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1306 r = &tu->queue[prev];
1307 if (r->resolution == resolution) {
1308 r->ticks += ticks;
1309 goto __wake;
1310 }
1311 }
1312 if (tu->qused >= tu->queue_size) {
1313 tu->overrun++;
1314 } else {
1315 r = &tu->queue[tu->qtail++];
1316 tu->qtail %= tu->queue_size;
1317 r->resolution = resolution;
1318 r->ticks = ticks;
1319 tu->qused++;
1320 }
1321 __wake:
1322 snd_kill_fasync(fasync: tu->fasync, SIGIO, POLL_IN);
1323 wake_up(&tu->qchange_sleep);
1324}
1325
1326static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1327 struct snd_timer_tread64 *tread)
1328{
1329 if (tu->qused >= tu->queue_size) {
1330 tu->overrun++;
1331 } else {
1332 memcpy(to: &tu->tqueue[tu->qtail++], from: tread, len: sizeof(*tread));
1333 tu->qtail %= tu->queue_size;
1334 tu->qused++;
1335 }
1336}
1337
1338static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1339 int event,
1340 struct timespec64 *tstamp,
1341 unsigned long resolution)
1342{
1343 struct snd_timer_user *tu = timeri->callback_data;
1344 struct snd_timer_tread64 r1;
1345
1346 if (event >= SNDRV_TIMER_EVENT_START &&
1347 event <= SNDRV_TIMER_EVENT_PAUSE)
1348 tu->tstamp = *tstamp;
1349 if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1350 return;
1351 memset(s: &r1, c: 0, n: sizeof(r1));
1352 r1.event = event;
1353 r1.tstamp_sec = tstamp->tv_sec;
1354 r1.tstamp_nsec = tstamp->tv_nsec;
1355 r1.val = resolution;
1356 scoped_guard(spinlock_irqsave, &tu->qlock)
1357 snd_timer_user_append_to_tqueue(tu, tread: &r1);
1358 snd_kill_fasync(fasync: tu->fasync, SIGIO, POLL_IN);
1359 wake_up(&tu->qchange_sleep);
1360}
1361
1362static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1363{
1364 struct snd_timer_user *tu = timeri->callback_data;
1365
1366 tu->disconnected = true;
1367 wake_up(&tu->qchange_sleep);
1368}
1369
1370static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1371 unsigned long resolution,
1372 unsigned long ticks)
1373{
1374 struct snd_timer_user *tu = timeri->callback_data;
1375 struct snd_timer_tread64 *r, r1;
1376 struct timespec64 tstamp;
1377 int prev, append = 0;
1378
1379 memset(s: &r1, c: 0, n: sizeof(r1));
1380 memset(s: &tstamp, c: 0, n: sizeof(tstamp));
1381 scoped_guard(spinlock, &tu->qlock) {
1382 if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1383 (1 << SNDRV_TIMER_EVENT_TICK))) == 0)
1384 return;
1385 if (tu->last_resolution != resolution || ticks > 0) {
1386 if (timer_tstamp_monotonic)
1387 ktime_get_ts64(ts: &tstamp);
1388 else
1389 ktime_get_real_ts64(tv: &tstamp);
1390 }
1391 if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1392 tu->last_resolution != resolution) {
1393 r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1394 r1.tstamp_sec = tstamp.tv_sec;
1395 r1.tstamp_nsec = tstamp.tv_nsec;
1396 r1.val = resolution;
1397 snd_timer_user_append_to_tqueue(tu, tread: &r1);
1398 tu->last_resolution = resolution;
1399 append++;
1400 }
1401 if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1402 break;
1403 if (ticks == 0)
1404 break;
1405 if (tu->qused > 0) {
1406 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1407 r = &tu->tqueue[prev];
1408 if (r->event == SNDRV_TIMER_EVENT_TICK) {
1409 r->tstamp_sec = tstamp.tv_sec;
1410 r->tstamp_nsec = tstamp.tv_nsec;
1411 r->val += ticks;
1412 append++;
1413 break;
1414 }
1415 }
1416 r1.event = SNDRV_TIMER_EVENT_TICK;
1417 r1.tstamp_sec = tstamp.tv_sec;
1418 r1.tstamp_nsec = tstamp.tv_nsec;
1419 r1.val = ticks;
1420 snd_timer_user_append_to_tqueue(tu, tread: &r1);
1421 append++;
1422 }
1423 if (append == 0)
1424 return;
1425 snd_kill_fasync(fasync: tu->fasync, SIGIO, POLL_IN);
1426 wake_up(&tu->qchange_sleep);
1427}
1428
1429static int realloc_user_queue(struct snd_timer_user *tu, int size)
1430{
1431 struct snd_timer_read *queue = NULL;
1432 struct snd_timer_tread64 *tqueue = NULL;
1433
1434 if (tu->tread) {
1435 tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
1436 if (!tqueue)
1437 return -ENOMEM;
1438 } else {
1439 queue = kcalloc(size, sizeof(*queue), GFP_KERNEL);
1440 if (!queue)
1441 return -ENOMEM;
1442 }
1443
1444 guard(spinlock_irq)(l: &tu->qlock);
1445 kfree(objp: tu->queue);
1446 kfree(objp: tu->tqueue);
1447 tu->queue_size = size;
1448 tu->queue = queue;
1449 tu->tqueue = tqueue;
1450 tu->qhead = tu->qtail = tu->qused = 0;
1451
1452 return 0;
1453}
1454
1455static int snd_timer_user_open(struct inode *inode, struct file *file)
1456{
1457 struct snd_timer_user *tu;
1458 int err;
1459
1460 err = stream_open(inode, filp: file);
1461 if (err < 0)
1462 return err;
1463
1464 tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1465 if (tu == NULL)
1466 return -ENOMEM;
1467 spin_lock_init(&tu->qlock);
1468 init_waitqueue_head(&tu->qchange_sleep);
1469 mutex_init(&tu->ioctl_lock);
1470 tu->ticks = 1;
1471 if (realloc_user_queue(tu, size: 128) < 0) {
1472 kfree(objp: tu);
1473 return -ENOMEM;
1474 }
1475 file->private_data = tu;
1476 return 0;
1477}
1478
1479static int snd_timer_user_release(struct inode *inode, struct file *file)
1480{
1481 struct snd_timer_user *tu;
1482
1483 if (file->private_data) {
1484 tu = file->private_data;
1485 file->private_data = NULL;
1486 scoped_guard(mutex, &tu->ioctl_lock) {
1487 if (tu->timeri) {
1488 snd_timer_close(tu->timeri);
1489 snd_timer_instance_free(tu->timeri);
1490 }
1491 }
1492 snd_fasync_free(fasync: tu->fasync);
1493 kfree(objp: tu->queue);
1494 kfree(objp: tu->tqueue);
1495 kfree(objp: tu);
1496 }
1497 return 0;
1498}
1499
1500static void snd_timer_user_zero_id(struct snd_timer_id *id)
1501{
1502 id->dev_class = SNDRV_TIMER_CLASS_NONE;
1503 id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1504 id->card = -1;
1505 id->device = -1;
1506 id->subdevice = -1;
1507}
1508
1509static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1510{
1511 id->dev_class = timer->tmr_class;
1512 id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1513 id->card = timer->card ? timer->card->number : -1;
1514 id->device = timer->tmr_device;
1515 id->subdevice = timer->tmr_subdevice;
1516}
1517
1518static void get_next_device(struct snd_timer_id *id)
1519{
1520 struct snd_timer *timer;
1521 struct list_head *p;
1522
1523 if (id->dev_class < 0) { /* first item */
1524 if (list_empty(head: &snd_timer_list))
1525 snd_timer_user_zero_id(id);
1526 else {
1527 timer = list_entry(snd_timer_list.next,
1528 struct snd_timer, device_list);
1529 snd_timer_user_copy_id(id, timer);
1530 }
1531 } else {
1532 switch (id->dev_class) {
1533 case SNDRV_TIMER_CLASS_GLOBAL:
1534 id->device = id->device < 0 ? 0 : id->device + 1;
1535 list_for_each(p, &snd_timer_list) {
1536 timer = list_entry(p, struct snd_timer, device_list);
1537 if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1538 snd_timer_user_copy_id(id, timer);
1539 break;
1540 }
1541 if (timer->tmr_device >= id->device) {
1542 snd_timer_user_copy_id(id, timer);
1543 break;
1544 }
1545 }
1546 if (p == &snd_timer_list)
1547 snd_timer_user_zero_id(id);
1548 break;
1549 case SNDRV_TIMER_CLASS_CARD:
1550 case SNDRV_TIMER_CLASS_PCM:
1551 if (id->card < 0) {
1552 id->card = 0;
1553 } else {
1554 if (id->device < 0) {
1555 id->device = 0;
1556 } else {
1557 if (id->subdevice < 0)
1558 id->subdevice = 0;
1559 else if (id->subdevice < INT_MAX)
1560 id->subdevice++;
1561 }
1562 }
1563 list_for_each(p, &snd_timer_list) {
1564 timer = list_entry(p, struct snd_timer, device_list);
1565 if (timer->tmr_class > id->dev_class) {
1566 snd_timer_user_copy_id(id, timer);
1567 break;
1568 }
1569 if (timer->tmr_class < id->dev_class)
1570 continue;
1571 if (timer->card->number > id->card) {
1572 snd_timer_user_copy_id(id, timer);
1573 break;
1574 }
1575 if (timer->card->number < id->card)
1576 continue;
1577 if (timer->tmr_device > id->device) {
1578 snd_timer_user_copy_id(id, timer);
1579 break;
1580 }
1581 if (timer->tmr_device < id->device)
1582 continue;
1583 if (timer->tmr_subdevice > id->subdevice) {
1584 snd_timer_user_copy_id(id, timer);
1585 break;
1586 }
1587 if (timer->tmr_subdevice < id->subdevice)
1588 continue;
1589 snd_timer_user_copy_id(id, timer);
1590 break;
1591 }
1592 if (p == &snd_timer_list)
1593 snd_timer_user_zero_id(id);
1594 break;
1595 default:
1596 snd_timer_user_zero_id(id);
1597 }
1598 }
1599}
1600
1601static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1602{
1603 struct snd_timer_id id;
1604
1605 if (copy_from_user(to: &id, from: _tid, n: sizeof(id)))
1606 return -EFAULT;
1607 scoped_guard(mutex, &register_mutex)
1608 get_next_device(id: &id);
1609 if (copy_to_user(to: _tid, from: &id, n: sizeof(*_tid)))
1610 return -EFAULT;
1611 return 0;
1612}
1613
1614static int snd_timer_user_ginfo(struct file *file,
1615 struct snd_timer_ginfo __user *_ginfo)
1616{
1617 struct snd_timer_ginfo *ginfo __free(kfree) = NULL;
1618 struct snd_timer_id tid;
1619 struct snd_timer *t;
1620 struct list_head *p;
1621
1622 ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1623 if (IS_ERR(ptr: ginfo))
1624 return PTR_ERR(ptr: ginfo);
1625
1626 tid = ginfo->tid;
1627 memset(s: ginfo, c: 0, n: sizeof(*ginfo));
1628 ginfo->tid = tid;
1629 scoped_guard(mutex, &register_mutex) {
1630 t = snd_timer_find(tid: &tid);
1631 if (!t)
1632 return -ENODEV;
1633 ginfo->card = t->card ? t->card->number : -1;
1634 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1635 ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1636 strscpy(ginfo->id, t->id, sizeof(ginfo->id));
1637 strscpy(ginfo->name, t->name, sizeof(ginfo->name));
1638 scoped_guard(spinlock_irq, &t->lock)
1639 ginfo->resolution = snd_timer_hw_resolution(timer: t);
1640 if (t->hw.resolution_min > 0) {
1641 ginfo->resolution_min = t->hw.resolution_min;
1642 ginfo->resolution_max = t->hw.resolution_max;
1643 }
1644 list_for_each(p, &t->open_list_head) {
1645 ginfo->clients++;
1646 }
1647 }
1648 if (copy_to_user(to: _ginfo, from: ginfo, n: sizeof(*ginfo)))
1649 return -EFAULT;
1650 return 0;
1651}
1652
1653static int timer_set_gparams(struct snd_timer_gparams *gparams)
1654{
1655 struct snd_timer *t;
1656
1657 guard(mutex)(T: &register_mutex);
1658 t = snd_timer_find(tid: &gparams->tid);
1659 if (!t)
1660 return -ENODEV;
1661 if (!list_empty(head: &t->open_list_head))
1662 return -EBUSY;
1663 if (!t->hw.set_period)
1664 return -ENOSYS;
1665 return t->hw.set_period(t, gparams->period_num, gparams->period_den);
1666}
1667
1668static int snd_timer_user_gparams(struct file *file,
1669 struct snd_timer_gparams __user *_gparams)
1670{
1671 struct snd_timer_gparams gparams;
1672
1673 if (copy_from_user(to: &gparams, from: _gparams, n: sizeof(gparams)))
1674 return -EFAULT;
1675 return timer_set_gparams(gparams: &gparams);
1676}
1677
1678static int snd_timer_user_gstatus(struct file *file,
1679 struct snd_timer_gstatus __user *_gstatus)
1680{
1681 struct snd_timer_gstatus gstatus;
1682 struct snd_timer_id tid;
1683 struct snd_timer *t;
1684
1685 if (copy_from_user(to: &gstatus, from: _gstatus, n: sizeof(gstatus)))
1686 return -EFAULT;
1687 tid = gstatus.tid;
1688 memset(s: &gstatus, c: 0, n: sizeof(gstatus));
1689 gstatus.tid = tid;
1690 scoped_guard(mutex, &register_mutex) {
1691 t = snd_timer_find(tid: &tid);
1692 if (t != NULL) {
1693 guard(spinlock_irq)(l: &t->lock);
1694 gstatus.resolution = snd_timer_hw_resolution(timer: t);
1695 if (t->hw.precise_resolution) {
1696 t->hw.precise_resolution(t, &gstatus.resolution_num,
1697 &gstatus.resolution_den);
1698 } else {
1699 gstatus.resolution_num = gstatus.resolution;
1700 gstatus.resolution_den = 1000000000uL;
1701 }
1702 } else {
1703 return -ENODEV;
1704 }
1705 }
1706 if (copy_to_user(to: _gstatus, from: &gstatus, n: sizeof(gstatus)))
1707 return -EFAULT;
1708 return 0;
1709}
1710
1711static int snd_timer_user_tselect(struct file *file,
1712 struct snd_timer_select __user *_tselect)
1713{
1714 struct snd_timer_user *tu;
1715 struct snd_timer_select tselect;
1716 char str[32];
1717 int err = 0;
1718
1719 tu = file->private_data;
1720 if (tu->timeri) {
1721 snd_timer_close(tu->timeri);
1722 snd_timer_instance_free(tu->timeri);
1723 tu->timeri = NULL;
1724 }
1725 if (copy_from_user(to: &tselect, from: _tselect, n: sizeof(tselect))) {
1726 err = -EFAULT;
1727 goto __err;
1728 }
1729 sprintf(buf: str, fmt: "application %i", current->pid);
1730 if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1731 tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1732 tu->timeri = snd_timer_instance_new(str);
1733 if (!tu->timeri) {
1734 err = -ENOMEM;
1735 goto __err;
1736 }
1737
1738 tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1739 tu->timeri->callback = tu->tread
1740 ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1741 tu->timeri->ccallback = snd_timer_user_ccallback;
1742 tu->timeri->callback_data = (void *)tu;
1743 tu->timeri->disconnect = snd_timer_user_disconnect;
1744
1745 err = snd_timer_open(tu->timeri, &tselect.id, current->pid);
1746 if (err < 0) {
1747 snd_timer_instance_free(tu->timeri);
1748 tu->timeri = NULL;
1749 }
1750
1751 __err:
1752 return err;
1753}
1754
1755static int snd_timer_user_info(struct file *file,
1756 struct snd_timer_info __user *_info)
1757{
1758 struct snd_timer_user *tu;
1759 struct snd_timer_info *info __free(kfree) = NULL;
1760 struct snd_timer *t;
1761
1762 tu = file->private_data;
1763 if (!tu->timeri)
1764 return -EBADFD;
1765 t = tu->timeri->timer;
1766 if (!t)
1767 return -EBADFD;
1768
1769 info = kzalloc(sizeof(*info), GFP_KERNEL);
1770 if (! info)
1771 return -ENOMEM;
1772 info->card = t->card ? t->card->number : -1;
1773 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1774 info->flags |= SNDRV_TIMER_FLG_SLAVE;
1775 strscpy(info->id, t->id, sizeof(info->id));
1776 strscpy(info->name, t->name, sizeof(info->name));
1777 scoped_guard(spinlock_irq, &t->lock)
1778 info->resolution = snd_timer_hw_resolution(timer: t);
1779 if (copy_to_user(to: _info, from: info, n: sizeof(*_info)))
1780 return -EFAULT;
1781 return 0;
1782}
1783
1784static int snd_timer_user_params(struct file *file,
1785 struct snd_timer_params __user *_params)
1786{
1787 struct snd_timer_user *tu;
1788 struct snd_timer_params params;
1789 struct snd_timer *t;
1790 int err;
1791
1792 tu = file->private_data;
1793 if (!tu->timeri)
1794 return -EBADFD;
1795 t = tu->timeri->timer;
1796 if (!t)
1797 return -EBADFD;
1798 if (copy_from_user(to: &params, from: _params, n: sizeof(params)))
1799 return -EFAULT;
1800 if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
1801 u64 resolution;
1802
1803 if (params.ticks < 1) {
1804 err = -EINVAL;
1805 goto _end;
1806 }
1807
1808 /* Don't allow resolution less than 1ms */
1809 resolution = snd_timer_resolution(tu->timeri);
1810 resolution *= params.ticks;
1811 if (resolution < 1000000) {
1812 err = -EINVAL;
1813 goto _end;
1814 }
1815 }
1816 if (params.queue_size > 0 &&
1817 (params.queue_size < 32 || params.queue_size > 1024)) {
1818 err = -EINVAL;
1819 goto _end;
1820 }
1821 if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1822 (1<<SNDRV_TIMER_EVENT_TICK)|
1823 (1<<SNDRV_TIMER_EVENT_START)|
1824 (1<<SNDRV_TIMER_EVENT_STOP)|
1825 (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1826 (1<<SNDRV_TIMER_EVENT_PAUSE)|
1827 (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1828 (1<<SNDRV_TIMER_EVENT_RESUME)|
1829 (1<<SNDRV_TIMER_EVENT_MSTART)|
1830 (1<<SNDRV_TIMER_EVENT_MSTOP)|
1831 (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1832 (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1833 (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1834 (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1835 err = -EINVAL;
1836 goto _end;
1837 }
1838 snd_timer_stop(tu->timeri);
1839 scoped_guard(spinlock_irq, &t->lock) {
1840 tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1841 SNDRV_TIMER_IFLG_EXCLUSIVE|
1842 SNDRV_TIMER_IFLG_EARLY_EVENT);
1843 if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1844 tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1845 if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1846 tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1847 if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1848 tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1849 }
1850 if (params.queue_size > 0 &&
1851 (unsigned int)tu->queue_size != params.queue_size) {
1852 err = realloc_user_queue(tu, size: params.queue_size);
1853 if (err < 0)
1854 goto _end;
1855 }
1856 scoped_guard(spinlock_irq, &tu->qlock) {
1857 tu->qhead = tu->qtail = tu->qused = 0;
1858 if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1859 if (tu->tread) {
1860 struct snd_timer_tread64 tread;
1861
1862 memset(s: &tread, c: 0, n: sizeof(tread));
1863 tread.event = SNDRV_TIMER_EVENT_EARLY;
1864 tread.tstamp_sec = 0;
1865 tread.tstamp_nsec = 0;
1866 tread.val = 0;
1867 snd_timer_user_append_to_tqueue(tu, tread: &tread);
1868 } else {
1869 struct snd_timer_read *r = &tu->queue[0];
1870
1871 r->resolution = 0;
1872 r->ticks = 0;
1873 tu->qused++;
1874 tu->qtail++;
1875 }
1876 }
1877 tu->filter = params.filter;
1878 tu->ticks = params.ticks;
1879 }
1880 err = 0;
1881 _end:
1882 if (copy_to_user(to: _params, from: &params, n: sizeof(params)))
1883 return -EFAULT;
1884 return err;
1885}
1886
1887static int snd_timer_user_status32(struct file *file,
1888 struct snd_timer_status32 __user *_status)
1889 {
1890 struct snd_timer_user *tu;
1891 struct snd_timer_status32 status;
1892
1893 tu = file->private_data;
1894 if (!tu->timeri)
1895 return -EBADFD;
1896 memset(s: &status, c: 0, n: sizeof(status));
1897 status.tstamp_sec = tu->tstamp.tv_sec;
1898 status.tstamp_nsec = tu->tstamp.tv_nsec;
1899 status.resolution = snd_timer_resolution(tu->timeri);
1900 status.lost = tu->timeri->lost;
1901 status.overrun = tu->overrun;
1902 scoped_guard(spinlock_irq, &tu->qlock)
1903 status.queue = tu->qused;
1904 if (copy_to_user(to: _status, from: &status, n: sizeof(status)))
1905 return -EFAULT;
1906 return 0;
1907}
1908
1909static int snd_timer_user_status64(struct file *file,
1910 struct snd_timer_status64 __user *_status)
1911{
1912 struct snd_timer_user *tu;
1913 struct snd_timer_status64 status;
1914
1915 tu = file->private_data;
1916 if (!tu->timeri)
1917 return -EBADFD;
1918 memset(s: &status, c: 0, n: sizeof(status));
1919 status.tstamp_sec = tu->tstamp.tv_sec;
1920 status.tstamp_nsec = tu->tstamp.tv_nsec;
1921 status.resolution = snd_timer_resolution(tu->timeri);
1922 status.lost = tu->timeri->lost;
1923 status.overrun = tu->overrun;
1924 scoped_guard(spinlock_irq, &tu->qlock)
1925 status.queue = tu->qused;
1926 if (copy_to_user(to: _status, from: &status, n: sizeof(status)))
1927 return -EFAULT;
1928 return 0;
1929}
1930
1931static int snd_timer_user_start(struct file *file)
1932{
1933 int err;
1934 struct snd_timer_user *tu;
1935
1936 tu = file->private_data;
1937 if (!tu->timeri)
1938 return -EBADFD;
1939 snd_timer_stop(tu->timeri);
1940 tu->timeri->lost = 0;
1941 tu->last_resolution = 0;
1942 err = snd_timer_start(tu->timeri, tu->ticks);
1943 if (err < 0)
1944 return err;
1945 return 0;
1946}
1947
1948static int snd_timer_user_stop(struct file *file)
1949{
1950 int err;
1951 struct snd_timer_user *tu;
1952
1953 tu = file->private_data;
1954 if (!tu->timeri)
1955 return -EBADFD;
1956 err = snd_timer_stop(tu->timeri);
1957 if (err < 0)
1958 return err;
1959 return 0;
1960}
1961
1962static int snd_timer_user_continue(struct file *file)
1963{
1964 int err;
1965 struct snd_timer_user *tu;
1966
1967 tu = file->private_data;
1968 if (!tu->timeri)
1969 return -EBADFD;
1970 /* start timer instead of continue if it's not used before */
1971 if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
1972 return snd_timer_user_start(file);
1973 tu->timeri->lost = 0;
1974 err = snd_timer_continue(tu->timeri);
1975 if (err < 0)
1976 return err;
1977 return 0;
1978}
1979
1980static int snd_timer_user_pause(struct file *file)
1981{
1982 int err;
1983 struct snd_timer_user *tu;
1984
1985 tu = file->private_data;
1986 if (!tu->timeri)
1987 return -EBADFD;
1988 err = snd_timer_pause(tu->timeri);
1989 if (err < 0)
1990 return err;
1991 return 0;
1992}
1993
1994static int snd_timer_user_tread(void __user *argp, struct snd_timer_user *tu,
1995 unsigned int cmd, bool compat)
1996{
1997 int __user *p = argp;
1998 int xarg, old_tread;
1999
2000 if (tu->timeri) /* too late */
2001 return -EBUSY;
2002 if (get_user(xarg, p))
2003 return -EFAULT;
2004
2005 old_tread = tu->tread;
2006
2007 if (!xarg)
2008 tu->tread = TREAD_FORMAT_NONE;
2009 else if (cmd == SNDRV_TIMER_IOCTL_TREAD64 ||
2010 (IS_ENABLED(CONFIG_64BIT) && !compat))
2011 tu->tread = TREAD_FORMAT_TIME64;
2012 else
2013 tu->tread = TREAD_FORMAT_TIME32;
2014
2015 if (tu->tread != old_tread &&
2016 realloc_user_queue(tu, size: tu->queue_size) < 0) {
2017 tu->tread = old_tread;
2018 return -ENOMEM;
2019 }
2020
2021 return 0;
2022}
2023
2024enum {
2025 SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
2026 SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
2027 SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
2028 SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
2029};
2030
2031#ifdef CONFIG_SND_UTIMER
2032/*
2033 * Since userspace-driven timers are passed to userspace, we need to have an identifier
2034 * which will allow us to use them (basically, the subdevice number of udriven timer).
2035 */
2036static DEFINE_IDA(snd_utimer_ids);
2037
2038static void snd_utimer_put_id(struct snd_utimer *utimer)
2039{
2040 int timer_id = utimer->id;
2041
2042 snd_BUG_ON(timer_id < 0 || timer_id >= SNDRV_UTIMERS_MAX_COUNT);
2043 ida_free(&snd_utimer_ids, timer_id);
2044}
2045
2046static int snd_utimer_take_id(void)
2047{
2048 return ida_alloc_max(&snd_utimer_ids, SNDRV_UTIMERS_MAX_COUNT - 1, GFP_KERNEL);
2049}
2050
2051static void snd_utimer_free(struct snd_utimer *utimer)
2052{
2053 snd_timer_free(utimer->timer);
2054 snd_utimer_put_id(utimer);
2055 kfree(utimer->name);
2056 kfree(utimer);
2057}
2058
2059static int snd_utimer_release(struct inode *inode, struct file *file)
2060{
2061 struct snd_utimer *utimer = (struct snd_utimer *)file->private_data;
2062
2063 snd_utimer_free(utimer);
2064 return 0;
2065}
2066
2067static int snd_utimer_trigger(struct file *file)
2068{
2069 struct snd_utimer *utimer = (struct snd_utimer *)file->private_data;
2070
2071 snd_timer_interrupt(utimer->timer, utimer->timer->sticks);
2072 return 0;
2073}
2074
2075static long snd_utimer_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
2076{
2077 switch (ioctl) {
2078 case SNDRV_TIMER_IOCTL_TRIGGER:
2079 return snd_utimer_trigger(file);
2080 }
2081
2082 return -ENOTTY;
2083}
2084
2085static const struct file_operations snd_utimer_fops = {
2086 .llseek = noop_llseek,
2087 .release = snd_utimer_release,
2088 .unlocked_ioctl = snd_utimer_ioctl,
2089};
2090
2091static int snd_utimer_start(struct snd_timer *t)
2092{
2093 return 0;
2094}
2095
2096static int snd_utimer_stop(struct snd_timer *t)
2097{
2098 return 0;
2099}
2100
2101static int snd_utimer_open(struct snd_timer *t)
2102{
2103 return 0;
2104}
2105
2106static int snd_utimer_close(struct snd_timer *t)
2107{
2108 return 0;
2109}
2110
2111static const struct snd_timer_hardware timer_hw = {
2112 .flags = SNDRV_TIMER_HW_AUTO | SNDRV_TIMER_HW_WORK,
2113 .open = snd_utimer_open,
2114 .close = snd_utimer_close,
2115 .start = snd_utimer_start,
2116 .stop = snd_utimer_stop,
2117};
2118
2119static int snd_utimer_create(struct snd_timer_uinfo *utimer_info,
2120 struct snd_utimer **r_utimer)
2121{
2122 struct snd_utimer *utimer;
2123 struct snd_timer *timer;
2124 struct snd_timer_id tid;
2125 int utimer_id;
2126 int err = 0;
2127
2128 if (!utimer_info || utimer_info->resolution == 0)
2129 return -EINVAL;
2130
2131 utimer = kzalloc(sizeof(*utimer), GFP_KERNEL);
2132 if (!utimer)
2133 return -ENOMEM;
2134
2135 /* We hold the ioctl lock here so we won't get a race condition when allocating id */
2136 utimer_id = snd_utimer_take_id();
2137 if (utimer_id < 0) {
2138 err = utimer_id;
2139 goto err_take_id;
2140 }
2141
2142 utimer->id = utimer_id;
2143
2144 utimer->name = kasprintf(GFP_KERNEL, "snd-utimer%d", utimer_id);
2145 if (!utimer->name) {
2146 err = -ENOMEM;
2147 goto err_get_name;
2148 }
2149
2150 tid.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
2151 tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
2152 tid.card = -1;
2153 tid.device = SNDRV_TIMER_GLOBAL_UDRIVEN;
2154 tid.subdevice = utimer_id;
2155
2156 err = snd_timer_new(NULL, utimer->name, &tid, &timer);
2157 if (err < 0) {
2158 pr_err("Can't create userspace-driven timer\n");
2159 goto err_timer_new;
2160 }
2161
2162 timer->module = THIS_MODULE;
2163 timer->hw = timer_hw;
2164 timer->hw.resolution = utimer_info->resolution;
2165 timer->hw.ticks = 1;
2166 timer->max_instances = MAX_SLAVE_INSTANCES;
2167
2168 utimer->timer = timer;
2169
2170 err = snd_timer_global_register(timer);
2171 if (err < 0) {
2172 pr_err("Can't register a userspace-driven timer\n");
2173 goto err_timer_reg;
2174 }
2175
2176 *r_utimer = utimer;
2177 return 0;
2178
2179err_timer_reg:
2180 snd_timer_free(timer);
2181err_timer_new:
2182 kfree(utimer->name);
2183err_get_name:
2184 snd_utimer_put_id(utimer);
2185err_take_id:
2186 kfree(utimer);
2187
2188 return err;
2189}
2190
2191static int snd_utimer_ioctl_create(struct file *file,
2192 struct snd_timer_uinfo __user *_utimer_info)
2193{
2194 struct snd_utimer *utimer;
2195 struct snd_timer_uinfo *utimer_info __free(kfree) = NULL;
2196 int err, timer_fd;
2197
2198 utimer_info = memdup_user(_utimer_info, sizeof(*utimer_info));
2199 if (IS_ERR(utimer_info))
2200 return PTR_ERR(utimer_info);
2201
2202 err = snd_utimer_create(utimer_info, &utimer);
2203 if (err < 0)
2204 return err;
2205
2206 utimer_info->id = utimer->id;
2207
2208 timer_fd = anon_inode_getfd(utimer->name, &snd_utimer_fops, utimer, O_RDWR | O_CLOEXEC);
2209 if (timer_fd < 0) {
2210 snd_utimer_free(utimer);
2211 return timer_fd;
2212 }
2213
2214 utimer_info->fd = timer_fd;
2215
2216 err = copy_to_user(_utimer_info, utimer_info, sizeof(*utimer_info));
2217 if (err) {
2218 /*
2219 * "Leak" the fd, as there is nothing we can do about it.
2220 * It might have been closed already since anon_inode_getfd
2221 * makes it available for userspace.
2222 *
2223 * We have to rely on the process exit path to do any
2224 * necessary cleanup (e.g. releasing the file).
2225 */
2226 return -EFAULT;
2227 }
2228
2229 return 0;
2230}
2231
2232#else
2233
2234static int snd_utimer_ioctl_create(struct file *file,
2235 struct snd_timer_uinfo __user *_utimer_info)
2236{
2237 return -ENOTTY;
2238}
2239
2240#endif
2241
2242static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2243 unsigned long arg, bool compat)
2244{
2245 struct snd_timer_user *tu;
2246 void __user *argp = (void __user *)arg;
2247 int __user *p = argp;
2248
2249 tu = file->private_data;
2250 switch (cmd) {
2251 case SNDRV_TIMER_IOCTL_PVERSION:
2252 return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
2253 case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
2254 return snd_timer_user_next_device(tid: argp);
2255 case SNDRV_TIMER_IOCTL_TREAD_OLD:
2256 case SNDRV_TIMER_IOCTL_TREAD64:
2257 return snd_timer_user_tread(argp, tu, cmd, compat);
2258 case SNDRV_TIMER_IOCTL_GINFO:
2259 return snd_timer_user_ginfo(file, ginfo: argp);
2260 case SNDRV_TIMER_IOCTL_GPARAMS:
2261 return snd_timer_user_gparams(file, gparams: argp);
2262 case SNDRV_TIMER_IOCTL_GSTATUS:
2263 return snd_timer_user_gstatus(file, gstatus: argp);
2264 case SNDRV_TIMER_IOCTL_SELECT:
2265 return snd_timer_user_tselect(file, tselect: argp);
2266 case SNDRV_TIMER_IOCTL_INFO:
2267 return snd_timer_user_info(file, info: argp);
2268 case SNDRV_TIMER_IOCTL_PARAMS:
2269 return snd_timer_user_params(file, params: argp);
2270 case SNDRV_TIMER_IOCTL_STATUS32:
2271 return snd_timer_user_status32(file, status: argp);
2272 case SNDRV_TIMER_IOCTL_STATUS64:
2273 return snd_timer_user_status64(file, status: argp);
2274 case SNDRV_TIMER_IOCTL_START:
2275 case SNDRV_TIMER_IOCTL_START_OLD:
2276 return snd_timer_user_start(file);
2277 case SNDRV_TIMER_IOCTL_STOP:
2278 case SNDRV_TIMER_IOCTL_STOP_OLD:
2279 return snd_timer_user_stop(file);
2280 case SNDRV_TIMER_IOCTL_CONTINUE:
2281 case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
2282 return snd_timer_user_continue(file);
2283 case SNDRV_TIMER_IOCTL_PAUSE:
2284 case SNDRV_TIMER_IOCTL_PAUSE_OLD:
2285 return snd_timer_user_pause(file);
2286 case SNDRV_TIMER_IOCTL_CREATE:
2287 return snd_utimer_ioctl_create(file, utimer_info: argp);
2288 }
2289 return -ENOTTY;
2290}
2291
2292static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2293 unsigned long arg)
2294{
2295 struct snd_timer_user *tu = file->private_data;
2296
2297 guard(mutex)(T: &tu->ioctl_lock);
2298 return __snd_timer_user_ioctl(file, cmd, arg, compat: false);
2299}
2300
2301static int snd_timer_user_fasync(int fd, struct file * file, int on)
2302{
2303 struct snd_timer_user *tu;
2304
2305 tu = file->private_data;
2306 return snd_fasync_helper(fd, file, on, fasyncp: &tu->fasync);
2307}
2308
2309static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
2310 size_t count, loff_t *offset)
2311{
2312 struct snd_timer_tread64 *tread;
2313 struct snd_timer_tread32 tread32;
2314 struct snd_timer_user *tu;
2315 long result = 0, unit;
2316 int qhead;
2317 int err = 0;
2318
2319 tu = file->private_data;
2320 switch (tu->tread) {
2321 case TREAD_FORMAT_TIME64:
2322 unit = sizeof(struct snd_timer_tread64);
2323 break;
2324 case TREAD_FORMAT_TIME32:
2325 unit = sizeof(struct snd_timer_tread32);
2326 break;
2327 case TREAD_FORMAT_NONE:
2328 unit = sizeof(struct snd_timer_read);
2329 break;
2330 default:
2331 WARN_ONCE(1, "Corrupt snd_timer_user\n");
2332 return -ENOTSUPP;
2333 }
2334
2335 mutex_lock(lock: &tu->ioctl_lock);
2336 spin_lock_irq(lock: &tu->qlock);
2337 while ((long)count - result >= unit) {
2338 while (!tu->qused) {
2339 wait_queue_entry_t wait;
2340
2341 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
2342 err = -EAGAIN;
2343 goto _error;
2344 }
2345
2346 set_current_state(TASK_INTERRUPTIBLE);
2347 init_waitqueue_entry(wq_entry: &wait, current);
2348 add_wait_queue(wq_head: &tu->qchange_sleep, wq_entry: &wait);
2349
2350 spin_unlock_irq(lock: &tu->qlock);
2351 mutex_unlock(lock: &tu->ioctl_lock);
2352 schedule();
2353 mutex_lock(lock: &tu->ioctl_lock);
2354 spin_lock_irq(lock: &tu->qlock);
2355
2356 remove_wait_queue(wq_head: &tu->qchange_sleep, wq_entry: &wait);
2357
2358 if (tu->disconnected) {
2359 err = -ENODEV;
2360 goto _error;
2361 }
2362 if (signal_pending(current)) {
2363 err = -ERESTARTSYS;
2364 goto _error;
2365 }
2366 }
2367
2368 qhead = tu->qhead++;
2369 tu->qhead %= tu->queue_size;
2370 tu->qused--;
2371 spin_unlock_irq(lock: &tu->qlock);
2372
2373 tread = &tu->tqueue[qhead];
2374
2375 switch (tu->tread) {
2376 case TREAD_FORMAT_TIME64:
2377 if (copy_to_user(to: buffer, from: tread,
2378 n: sizeof(struct snd_timer_tread64)))
2379 err = -EFAULT;
2380 break;
2381 case TREAD_FORMAT_TIME32:
2382 memset(s: &tread32, c: 0, n: sizeof(tread32));
2383 tread32 = (struct snd_timer_tread32) {
2384 .event = tread->event,
2385 .tstamp_sec = tread->tstamp_sec,
2386 .tstamp_nsec = tread->tstamp_nsec,
2387 .val = tread->val,
2388 };
2389
2390 if (copy_to_user(to: buffer, from: &tread32, n: sizeof(tread32)))
2391 err = -EFAULT;
2392 break;
2393 case TREAD_FORMAT_NONE:
2394 if (copy_to_user(to: buffer, from: &tu->queue[qhead],
2395 n: sizeof(struct snd_timer_read)))
2396 err = -EFAULT;
2397 break;
2398 default:
2399 err = -ENOTSUPP;
2400 break;
2401 }
2402
2403 spin_lock_irq(lock: &tu->qlock);
2404 if (err < 0)
2405 goto _error;
2406 result += unit;
2407 buffer += unit;
2408 }
2409 _error:
2410 spin_unlock_irq(lock: &tu->qlock);
2411 mutex_unlock(lock: &tu->ioctl_lock);
2412 return result > 0 ? result : err;
2413}
2414
2415static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
2416{
2417 __poll_t mask;
2418 struct snd_timer_user *tu;
2419
2420 tu = file->private_data;
2421
2422 poll_wait(filp: file, wait_address: &tu->qchange_sleep, p: wait);
2423
2424 mask = 0;
2425 guard(spinlock_irq)(l: &tu->qlock);
2426 if (tu->qused)
2427 mask |= EPOLLIN | EPOLLRDNORM;
2428 if (tu->disconnected)
2429 mask |= EPOLLERR;
2430
2431 return mask;
2432}
2433
2434#ifdef CONFIG_COMPAT
2435#include "timer_compat.c"
2436#else
2437#define snd_timer_user_ioctl_compat NULL
2438#endif
2439
2440static const struct file_operations snd_timer_f_ops =
2441{
2442 .owner = THIS_MODULE,
2443 .read = snd_timer_user_read,
2444 .open = snd_timer_user_open,
2445 .release = snd_timer_user_release,
2446 .poll = snd_timer_user_poll,
2447 .unlocked_ioctl = snd_timer_user_ioctl,
2448 .compat_ioctl = snd_timer_user_ioctl_compat,
2449 .fasync = snd_timer_user_fasync,
2450};
2451
2452/* unregister the system timer */
2453static void snd_timer_free_all(void)
2454{
2455 struct snd_timer *timer, *n;
2456
2457 list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2458 snd_timer_free(timer);
2459}
2460
2461static struct device *timer_dev;
2462
2463/*
2464 * ENTRY functions
2465 */
2466
2467static int __init alsa_timer_init(void)
2468{
2469 int err;
2470
2471 err = snd_device_alloc(dev_p: &timer_dev, NULL);
2472 if (err < 0)
2473 return err;
2474 dev_set_name(dev: timer_dev, name: "timer");
2475
2476#ifdef SNDRV_OSS_INFO_DEV_TIMERS
2477 snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2478 "system timer");
2479#endif
2480
2481 err = snd_timer_register_system();
2482 if (err < 0) {
2483 pr_err("ALSA: unable to register system timer (%i)\n", err);
2484 goto put_timer;
2485 }
2486
2487 err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, dev: 0,
2488 f_ops: &snd_timer_f_ops, NULL, device: timer_dev);
2489 if (err < 0) {
2490 pr_err("ALSA: unable to register timer device (%i)\n", err);
2491 snd_timer_free_all();
2492 goto put_timer;
2493 }
2494
2495 snd_timer_proc_init();
2496 return 0;
2497
2498put_timer:
2499 put_device(dev: timer_dev);
2500 return err;
2501}
2502
2503static void __exit alsa_timer_exit(void)
2504{
2505 snd_unregister_device(dev: timer_dev);
2506 snd_timer_free_all();
2507 put_device(dev: timer_dev);
2508 snd_timer_proc_done();
2509#ifdef SNDRV_OSS_INFO_DEV_TIMERS
2510 snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2511#endif
2512}
2513
2514module_init(alsa_timer_init)
2515module_exit(alsa_timer_exit)
2516