projects/linux·blob master · refs

710 lines · 17.5 KiB

1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ALSA sequencer Timing queue handling
4 * Copyright (c) 1998-1999 by Frank van de Pol <[email protected]>
5 *
6 * MAJOR CHANGES
7 * Nov. 13, 1999 Takashi Iwai <[email protected]>
8 * - Queues are allocated dynamically via ioctl.
9 * - When owner client is deleted, all owned queues are deleted, too.
10 * - Owner of unlocked queue is kept unmodified even if it is
11 * manipulated by other clients.
12 * - Owner field in SET_QUEUE_OWNER ioctl must be identical with the
13 * caller client. i.e. Changing owner to a third client is not
14 * allowed.
15 *
16 * Aug. 30, 2000 Takashi Iwai
17 * - Queues are managed in static array again, but with better way.
18 * The API itself is identical.
19 * - The queue is locked when struct snd_seq_queue pointer is returned via
20 * queueptr(). This pointer *MUST* be released afterward by
21 * queuefree(ptr).
22 * - Addition of experimental sync support.
23 */
24
25#include <linux/init.h>
26#include <linux/slab.h>
27#include <sound/core.h>
28
29#include "seq_memory.h"
30#include "seq_queue.h"
31#include "seq_clientmgr.h"
32#include "seq_fifo.h"
33#include "seq_timer.h"
34#include "seq_info.h"
35
36/* list of allocated queues */
37static struct snd_seq_queue *queue_list[SNDRV_SEQ_MAX_QUEUES];
38static DEFINE_SPINLOCK(queue_list_lock);
39/* number of queues allocated */
40static int num_queues;
41
42int snd_seq_queue_get_cur_queues(void)
43{
44 return num_queues;
45}
46
47/*----------------------------------------------------------------*/
48
49/* assign queue id and insert to list */
50static int queue_list_add(struct snd_seq_queue *q)
51{
52 int i;
53
54 guard(spinlock_irqsave)(&queue_list_lock);
55 for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
56 if (! queue_list[i]) {
57 queue_list[i] = q;
58 q->queue = i;
59 num_queues++;
60 return i;
61 }
62 }
63 return -1;
64}
65
66static struct snd_seq_queue *queue_list_remove(int id, int client)
67{
68 struct snd_seq_queue *q;
69
70 guard(spinlock_irqsave)(&queue_list_lock);
71 q = queue_list[id];
72 if (q) {
73 guard(spinlock)(&q->owner_lock);
74 if (q->owner == client) {
75 /* found */
76 q->klocked = 1;
77 queue_list[id] = NULL;
78 num_queues--;
79 return q;
80 }
81 }
82 return NULL;
83}
84
85/*----------------------------------------------------------------*/
86
87/* create new queue (constructor) */
88static struct snd_seq_queue *queue_new(int owner, int locked)
89{
90 struct snd_seq_queue *q;
91
92 q = kzalloc_obj(*q);
93 if (!q)
94 return NULL;
95
96 spin_lock_init(&q->owner_lock);
97 spin_lock_init(&q->check_lock);
98 mutex_init(&q->timer_mutex);
99 snd_use_lock_init(&q->use_lock);
100 q->queue = -1;
101
102 q->tickq = snd_seq_prioq_new();
103 q->timeq = snd_seq_prioq_new();
104 q->timer = snd_seq_timer_new();
105 if (q->tickq == NULL || q->timeq == NULL || q->timer == NULL) {
106 snd_seq_prioq_delete(&q->tickq);
107 snd_seq_prioq_delete(&q->timeq);
108 snd_seq_timer_delete(&q->timer);
109 kfree(q);
110 return NULL;
111 }
112
113 q->owner = owner;
114 q->locked = locked;
115 q->klocked = 0;
116
117 return q;
118}
119
120/* delete queue (destructor) */
121static void queue_delete(struct snd_seq_queue *q)
122{
123 /* stop and release the timer */
124 mutex_lock(&q->timer_mutex);
125 snd_seq_timer_stop(q->timer);
126 snd_seq_timer_close(q);
127 mutex_unlock(&q->timer_mutex);
128 /* wait until access free */
129 snd_use_lock_sync(&q->use_lock);
130 /* release resources... */
131 snd_seq_prioq_delete(&q->tickq);
132 snd_seq_prioq_delete(&q->timeq);
133 snd_seq_timer_delete(&q->timer);
134
135 kfree(q);
136}
137
138
139/*----------------------------------------------------------------*/
140
141/* delete all existing queues */
142void snd_seq_queues_delete(void)
143{
144 int i;
145
146 /* clear list */
147 for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
148 if (queue_list[i])
149 queue_delete(queue_list[i]);
150 }
151}
152
153static void queue_use(struct snd_seq_queue *queue, int client, int use);
154
155/* allocate a new queue -
156 * return pointer to new queue or ERR_PTR(-errno) for error
157 * The new queue's use_lock is set to 1. It is the caller's responsibility to
158 * call snd_use_lock_free(&q->use_lock).
159 */
160struct snd_seq_queue *snd_seq_queue_alloc(int client, int locked, unsigned int info_flags)
161{
162 struct snd_seq_queue *q;
163
164 q = queue_new(client, locked);
165 if (q == NULL)
166 return ERR_PTR(-ENOMEM);
167 q->info_flags = info_flags;
168 queue_use(q, client, 1);
169 snd_use_lock_use(&q->use_lock);
170 if (queue_list_add(q) < 0) {
171 snd_use_lock_free(&q->use_lock);
172 queue_delete(q);
173 return ERR_PTR(-ENOMEM);
174 }
175 return q;
176}
177
178/* delete a queue - queue must be owned by the client */
179int snd_seq_queue_delete(int client, int queueid)
180{
181 struct snd_seq_queue *q;
182
183 if (queueid < 0 || queueid >= SNDRV_SEQ_MAX_QUEUES)
184 return -EINVAL;
185 q = queue_list_remove(queueid, client);
186 if (q == NULL)
187 return -EINVAL;
188 queue_delete(q);
189
190 return 0;
191}
192
193
194/* return pointer to queue structure for specified id */
195struct snd_seq_queue *queueptr(int queueid)
196{
197 struct snd_seq_queue *q;
198
199 if (queueid < 0 || queueid >= SNDRV_SEQ_MAX_QUEUES)
200 return NULL;
201 guard(spinlock_irqsave)(&queue_list_lock);
202 q = queue_list[queueid];
203 if (q)
204 snd_use_lock_use(&q->use_lock);
205 return q;
206}
207
208/* return the (first) queue matching with the specified name */
209struct snd_seq_queue *snd_seq_queue_find_name(char *name)
210{
211 int i;
212
213 for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
214 struct snd_seq_queue *q __free(snd_seq_queue) =
215 queueptr(i);
216
217 if (q) {
218 if (strncmp(q->name, name, sizeof(q->name)) == 0)
219 return no_free_ptr(q);
220 }
221 }
222 return NULL;
223}
224
225
226/* -------------------------------------------------------- */
227
228#define MAX_CELL_PROCESSES_IN_QUEUE 1000
229
230void snd_seq_check_queue(struct snd_seq_queue *q, int atomic, int hop)
231{
232 struct snd_seq_event_cell *cell;
233 snd_seq_tick_time_t cur_tick;
234 snd_seq_real_time_t cur_time;
235 int processed = 0;
236
237 if (q == NULL)
238 return;
239
240 /* make this function non-reentrant */
241 scoped_guard(spinlock_irqsave, &q->check_lock) {
242 if (q->check_blocked) {
243 q->check_again = 1;
244 return; /* other thread is already checking queues */
245 }
246 q->check_blocked = 1;
247 }
248
249 __again:
250 /* Process tick queue... */
251 cur_tick = snd_seq_timer_get_cur_tick(q->timer);
252 for (;;) {
253 cell = snd_seq_prioq_cell_out(q->tickq, &cur_tick);
254 if (!cell)
255 break;
256 snd_seq_dispatch_event(cell, atomic, hop);
257 if (++processed >= MAX_CELL_PROCESSES_IN_QUEUE)
258 goto out; /* the rest processed at the next batch */
259 }
260
261 /* Process time queue... */
262 cur_time = snd_seq_timer_get_cur_time(q->timer, false);
263 for (;;) {
264 cell = snd_seq_prioq_cell_out(q->timeq, &cur_time);
265 if (!cell)
266 break;
267 snd_seq_dispatch_event(cell, atomic, hop);
268 if (++processed >= MAX_CELL_PROCESSES_IN_QUEUE)
269 goto out; /* the rest processed at the next batch */
270 }
271
272 out:
273 /* free lock */
274 scoped_guard(spinlock_irqsave, &q->check_lock) {
275 if (q->check_again) {
276 q->check_again = 0;
277 if (processed < MAX_CELL_PROCESSES_IN_QUEUE)
278 goto __again;
279 }
280 q->check_blocked = 0;
281 }
282}
283
284
285/* enqueue a event to singe queue */
286int snd_seq_enqueue_event(struct snd_seq_event_cell *cell, int atomic, int hop)
287{
288 int dest, err;
289
290 if (snd_BUG_ON(!cell))
291 return -EINVAL;
292 dest = cell->event.queue; /* destination queue */
293
294 struct snd_seq_queue *q __free(snd_seq_queue) =
295 queueptr(dest);
296 if (q == NULL)
297 return -EINVAL;
298 /* handle relative time stamps, convert them into absolute */
299 if ((cell->event.flags & SNDRV_SEQ_TIME_MODE_MASK) == SNDRV_SEQ_TIME_MODE_REL) {
300 switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
301 case SNDRV_SEQ_TIME_STAMP_TICK:
302 cell->event.time.tick += q->timer->tick.cur_tick;
303 break;
304
305 case SNDRV_SEQ_TIME_STAMP_REAL:
306 snd_seq_inc_real_time(&cell->event.time.time,
307 &q->timer->cur_time);
308 break;
309 }
310 cell->event.flags &= ~SNDRV_SEQ_TIME_MODE_MASK;
311 cell->event.flags |= SNDRV_SEQ_TIME_MODE_ABS;
312 }
313 /* enqueue event in the real-time or midi queue */
314 switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
315 case SNDRV_SEQ_TIME_STAMP_TICK:
316 err = snd_seq_prioq_cell_in(q->tickq, cell);
317 break;
318
319 case SNDRV_SEQ_TIME_STAMP_REAL:
320 default:
321 err = snd_seq_prioq_cell_in(q->timeq, cell);
322 break;
323 }
324
325 if (err < 0)
326 return err;
327
328 /* trigger dispatching */
329 snd_seq_check_queue(q, atomic, hop);
330
331 return 0;
332}
333
334
335/*----------------------------------------------------------------*/
336
337static inline int check_access(struct snd_seq_queue *q, int client)
338{
339 return (q->owner == client) || (!q->locked && !q->klocked);
340}
341
342/* check if the client has permission to modify queue parameters.
343 * if it does, lock the queue
344 */
345static int queue_access_lock(struct snd_seq_queue *q, int client)
346{
347 int access_ok;
348
349 guard(spinlock_irqsave)(&q->owner_lock);
350 access_ok = check_access(q, client);
351 if (access_ok)
352 q->klocked = 1;
353 return access_ok;
354}
355
356/* unlock the queue */
357static inline void queue_access_unlock(struct snd_seq_queue *q)
358{
359 guard(spinlock_irqsave)(&q->owner_lock);
360 q->klocked = 0;
361}
362
363/* exported - only checking permission */
364int snd_seq_queue_check_access(int queueid, int client)
365{
366 struct snd_seq_queue *q __free(snd_seq_queue) = queueptr(queueid);
367
368 if (! q)
369 return 0;
370 guard(spinlock_irqsave)(&q->owner_lock);
371 return check_access(q, client);
372}
373
374/*----------------------------------------------------------------*/
375
376/*
377 * change queue's owner and permission
378 */
379int snd_seq_queue_set_owner(int queueid, int client, int locked)
380{
381 struct snd_seq_queue *q __free(snd_seq_queue) = queueptr(queueid);
382
383 if (q == NULL)
384 return -EINVAL;
385
386 if (!queue_access_lock(q, client))
387 return -EPERM;
388
389 scoped_guard(spinlock_irqsave, &q->owner_lock) {
390 q->locked = locked ? 1 : 0;
391 q->owner = client;
392 }
393 queue_access_unlock(q);
394
395 return 0;
396}
397
398
399/*----------------------------------------------------------------*/
400
401/* open timer -
402 * q->use mutex should be down before calling this function to avoid
403 * confliction with snd_seq_queue_use()
404 */
405int snd_seq_queue_timer_open(int queueid)
406{
407 int result = 0;
408 struct snd_seq_timer *tmr;
409 struct snd_seq_queue *queue __free(snd_seq_queue) =
410 queueptr(queueid);
411
412 if (queue == NULL)
413 return -EINVAL;
414 tmr = queue->timer;
415 result = snd_seq_timer_open(queue);
416 if (result < 0) {
417 snd_seq_timer_defaults(tmr);
418 result = snd_seq_timer_open(queue);
419 }
420 return result;
421}
422
423/* close timer -
424 * q->use mutex should be down before calling this function
425 */
426int snd_seq_queue_timer_close(int queueid)
427{
428 int result = 0;
429 struct snd_seq_queue *queue __free(snd_seq_queue) =
430 queueptr(queueid);
431
432 if (queue == NULL)
433 return -EINVAL;
434 snd_seq_timer_close(queue);
435 return result;
436}
437
438/* change queue tempo and ppq */
439int snd_seq_queue_timer_set_tempo(int queueid, int client,
440 struct snd_seq_queue_tempo *info)
441{
442 struct snd_seq_queue *q __free(snd_seq_queue) = queueptr(queueid);
443 int result;
444
445 if (q == NULL)
446 return -EINVAL;
447 if (!queue_access_lock(q, client))
448 return -EPERM;
449
450 result = snd_seq_timer_set_tempo_ppq(q->timer, info->tempo, info->ppq,
451 info->tempo_base);
452 if (result >= 0 && info->skew_base > 0)
453 result = snd_seq_timer_set_skew(q->timer, info->skew_value,
454 info->skew_base);
455 queue_access_unlock(q);
456 return result;
457}
458
459/* use or unuse this queue */
460static void queue_use(struct snd_seq_queue *queue, int client, int use)
461{
462 if (use) {
463 if (!test_and_set_bit(client, queue->clients_bitmap))
464 queue->clients++;
465 } else {
466 if (test_and_clear_bit(client, queue->clients_bitmap))
467 queue->clients--;
468 }
469 if (queue->clients) {
470 if (use && queue->clients == 1)
471 snd_seq_timer_defaults(queue->timer);
472 snd_seq_timer_open(queue);
473 } else {
474 snd_seq_timer_close(queue);
475 }
476}
477
478/* use or unuse this queue -
479 * if it is the first client, starts the timer.
480 * if it is not longer used by any clients, stop the timer.
481 */
482int snd_seq_queue_use(int queueid, int client, int use)
483{
484 struct snd_seq_queue *queue __free(snd_seq_queue) =
485 queueptr(queueid);
486
487 if (queue == NULL)
488 return -EINVAL;
489 guard(mutex)(&queue->timer_mutex);
490 queue_use(queue, client, use);
491 return 0;
492}
493
494/*
495 * check if queue is used by the client
496 * return negative value if the queue is invalid.
497 * return 0 if not used, 1 if used.
498 */
499int snd_seq_queue_is_used(int queueid, int client)
500{
501 struct snd_seq_queue *q __free(snd_seq_queue) =
502 queueptr(queueid);
503
504 if (q == NULL)
505 return -EINVAL; /* invalid queue */
506 return test_bit(client, q->clients_bitmap) ? 1 : 0;
507}
508
509
510/*----------------------------------------------------------------*/
511
512/* final stage notification -
513 * remove cells for no longer exist client (for non-owned queue)
514 * or delete this queue (for owned queue)
515 */
516void snd_seq_queue_client_leave(int client)
517{
518 int i;
519
520 /* delete own queues from queue list */
521 for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
522 struct snd_seq_queue *q = queue_list_remove(i, client);
523 if (q)
524 queue_delete(q);
525 }
526
527 /* remove cells from existing queues -
528 * they are not owned by this client
529 */
530 for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
531 struct snd_seq_queue *q __free(snd_seq_queue) = queueptr(i);
532 if (!q)
533 continue;
534 if (test_bit(client, q->clients_bitmap)) {
535 snd_seq_prioq_leave(q->tickq, client, 0);
536 snd_seq_prioq_leave(q->timeq, client, 0);
537 snd_seq_queue_use(q->queue, client, 0);
538 }
539 }
540}
541
542
543
544/*----------------------------------------------------------------*/
545
546/* remove cells based on flush criteria */
547void snd_seq_queue_remove_cells(int client, struct snd_seq_remove_events *info)
548{
549 int i;
550
551 for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
552 struct snd_seq_queue *q __free(snd_seq_queue) = queueptr(i);
553 if (!q)
554 continue;
555 if (test_bit(client, q->clients_bitmap) &&
556 (! (info->remove_mode & SNDRV_SEQ_REMOVE_DEST) ||
557 q->queue == info->queue)) {
558 snd_seq_prioq_remove_events(q->tickq, client, info);
559 snd_seq_prioq_remove_events(q->timeq, client, info);
560 }
561 }
562}
563
564/*----------------------------------------------------------------*/
565
566/*
567 * send events to all subscribed ports
568 */
569static void queue_broadcast_event(struct snd_seq_queue *q, struct snd_seq_event *ev,
570 int atomic, int hop)
571{
572 struct snd_seq_event sev;
573
574 sev = *ev;
575
576 sev.flags = SNDRV_SEQ_TIME_STAMP_TICK|SNDRV_SEQ_TIME_MODE_ABS;
577 sev.time.tick = q->timer->tick.cur_tick;
578 sev.queue = q->queue;
579 sev.data.queue.queue = q->queue;
580
581 /* broadcast events from Timer port */
582 sev.source.client = SNDRV_SEQ_CLIENT_SYSTEM;
583 sev.source.port = SNDRV_SEQ_PORT_SYSTEM_TIMER;
584 sev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
585 snd_seq_kernel_client_dispatch(SNDRV_SEQ_CLIENT_SYSTEM, &sev, atomic, hop);
586}
587
588/*
589 * process a received queue-control event.
590 * this function is exported for seq_sync.c.
591 */
592static void snd_seq_queue_process_event(struct snd_seq_queue *q,
593 struct snd_seq_event *ev,
594 int atomic, int hop)
595{
596 switch (ev->type) {
597 case SNDRV_SEQ_EVENT_START:
598 snd_seq_prioq_leave(q->tickq, ev->source.client, 1);
599 snd_seq_prioq_leave(q->timeq, ev->source.client, 1);
600 if (! snd_seq_timer_start(q->timer))
601 queue_broadcast_event(q, ev, atomic, hop);
602 break;
603
604 case SNDRV_SEQ_EVENT_CONTINUE:
605 if (! snd_seq_timer_continue(q->timer))
606 queue_broadcast_event(q, ev, atomic, hop);
607 break;
608
609 case SNDRV_SEQ_EVENT_STOP:
610 snd_seq_timer_stop(q->timer);
611 queue_broadcast_event(q, ev, atomic, hop);
612 break;
613
614 case SNDRV_SEQ_EVENT_TEMPO:
615 snd_seq_timer_set_tempo(q->timer, ev->data.queue.param.value);
616 queue_broadcast_event(q, ev, atomic, hop);
617 break;
618
619 case SNDRV_SEQ_EVENT_SETPOS_TICK:
620 if (snd_seq_timer_set_position_tick(q->timer, ev->data.queue.param.time.tick) == 0) {
621 queue_broadcast_event(q, ev, atomic, hop);
622 }
623 break;
624
625 case SNDRV_SEQ_EVENT_SETPOS_TIME:
626 if (snd_seq_timer_set_position_time(q->timer, ev->data.queue.param.time.time) == 0) {
627 queue_broadcast_event(q, ev, atomic, hop);
628 }
629 break;
630 case SNDRV_SEQ_EVENT_QUEUE_SKEW:
631 if (snd_seq_timer_set_skew(q->timer,
632 ev->data.queue.param.skew.value,
633 ev->data.queue.param.skew.base) == 0) {
634 queue_broadcast_event(q, ev, atomic, hop);
635 }
636 break;
637 }
638}
639
640
641/*
642 * Queue control via timer control port:
643 * this function is exported as a callback of timer port.
644 */
645int snd_seq_control_queue(struct snd_seq_event *ev, int atomic, int hop)
646{
647 if (snd_BUG_ON(!ev))
648 return -EINVAL;
649
650 struct snd_seq_queue *q __free(snd_seq_queue) =
651 queueptr(ev->data.queue.queue);
652
653 if (q == NULL)
654 return -EINVAL;
655
656 if (!queue_access_lock(q, ev->source.client))
657 return -EPERM;
658
659 snd_seq_queue_process_event(q, ev, atomic, hop);
660
661 queue_access_unlock(q);
662 return 0;
663}
664
665
666/*----------------------------------------------------------------*/
667
668#ifdef CONFIG_SND_PROC_FS
669/* exported to seq_info.c */
670void snd_seq_info_queues_read(struct snd_info_entry *entry,
671 struct snd_info_buffer *buffer)
672{
673 int i, bpm;
674 struct snd_seq_timer *tmr;
675 bool locked;
676 int owner;
677
678 for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
679 struct snd_seq_queue *q __free(snd_seq_queue) = queueptr(i);
680 if (!q)
681 continue;
682
683 tmr = q->timer;
684 if (tmr->tempo)
685 bpm = (60000 * tmr->tempo_base) / tmr->tempo;
686 else
687 bpm = 0;
688
689 scoped_guard(spinlock_irq, &q->owner_lock) {
690 locked = q->locked;
691 owner = q->owner;
692 }
693
694 snd_iprintf(buffer, "queue %d: [%s]\n", q->queue, q->name);
695 snd_iprintf(buffer, "owned by client : %d\n", owner);
696 snd_iprintf(buffer, "lock status : %s\n", locked ? "Locked" : "Free");
697 snd_iprintf(buffer, "queued time events : %d\n", snd_seq_prioq_avail(q->timeq));
698 snd_iprintf(buffer, "queued tick events : %d\n", snd_seq_prioq_avail(q->tickq));
699 snd_iprintf(buffer, "timer state : %s\n", tmr->running ? "Running" : "Stopped");
700 snd_iprintf(buffer, "timer PPQ : %d\n", tmr->ppq);
701 snd_iprintf(buffer, "current tempo : %d\n", tmr->tempo);
702 snd_iprintf(buffer, "tempo base : %d ns\n", tmr->tempo_base);
703 snd_iprintf(buffer, "current BPM : %d\n", bpm);
704 snd_iprintf(buffer, "current time : %d.%09d s\n", tmr->cur_time.tv_sec, tmr->cur_time.tv_nsec);
705 snd_iprintf(buffer, "current tick : %d\n", tmr->tick.cur_tick);
706 snd_iprintf(buffer, "\n");
707 }
708}
709#endif /* CONFIG_SND_PROC_FS */
710