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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ALSA sequencer Ports
4 * Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
5 * Jaroslav Kysela <perex@perex.cz>
6 */
7
8#include <sound/core.h>
9#include <linux/slab.h>
10#include <linux/module.h>
11#include "seq_system.h"
12#include "seq_ports.h"
13#include "seq_clientmgr.h"
14
15/*
16
17 registration of client ports
18
19 */
20
21
22/*
23
24NOTE: the current implementation of the port structure as a linked list is
25not optimal for clients that have many ports. For sending messages to all
26subscribers of a port we first need to find the address of the port
27structure, which means we have to traverse the list. A direct access table
28(array) would be better, but big preallocated arrays waste memory.
29
30Possible actions:
31
321) leave it this way, a client does normaly does not have more than a few
33ports
34
352) replace the linked list of ports by a array of pointers which is
36dynamicly kmalloced. When a port is added or deleted we can simply allocate
37a new array, copy the corresponding pointers, and delete the old one. We
38then only need a pointer to this array, and an integer that tells us how
39much elements are in array.
40
41*/
42
43/* return pointer to port structure - port is locked if found */
44struct snd_seq_client_port *snd_seq_port_use_ptr(struct snd_seq_client *client,
45 int num)
46{
47 struct snd_seq_client_port *port;
48
49 if (client == NULL)
50 return NULL;
51 read_lock(&client->ports_lock);
52 list_for_each_entry(port, &client->ports_list_head, list) {
53 if (port->addr.port == num) {
54 if (port->closing)
55 break; /* deleting now */
56 snd_use_lock_use(&port->use_lock);
57 read_unlock(&client->ports_lock);
58 return port;
59 }
60 }
61 read_unlock(&client->ports_lock);
62 return NULL; /* not found */
63}
64
65
66/* search for the next port - port is locked if found */
67struct snd_seq_client_port *snd_seq_port_query_nearest(struct snd_seq_client *client,
68 struct snd_seq_port_info *pinfo)
69{
70 int num;
71 struct snd_seq_client_port *port, *found;
72
73 num = pinfo->addr.port;
74 found = NULL;
75 read_lock(&client->ports_lock);
76 list_for_each_entry(port, &client->ports_list_head, list) {
77 if (port->addr.port < num)
78 continue;
79 if (port->addr.port == num) {
80 found = port;
81 break;
82 }
83 if (found == NULL || port->addr.port < found->addr.port)
84 found = port;
85 }
86 if (found) {
87 if (found->closing)
88 found = NULL;
89 else
90 snd_use_lock_use(&found->use_lock);
91 }
92 read_unlock(&client->ports_lock);
93 return found;
94}
95
96
97/* initialize snd_seq_port_subs_info */
98static void port_subs_info_init(struct snd_seq_port_subs_info *grp)
99{
100 INIT_LIST_HEAD(&grp->list_head);
101 grp->count = 0;
102 grp->exclusive = 0;
103 rwlock_init(&grp->list_lock);
104 init_rwsem(&grp->list_mutex);
105 grp->open = NULL;
106 grp->close = NULL;
107}
108
109
110/* create a port, port number is returned (-1 on failure);
111 * the caller needs to unref the port via snd_seq_port_unlock() appropriately
112 */
113struct snd_seq_client_port *snd_seq_create_port(struct snd_seq_client *client,
114 int port)
115{
116 struct snd_seq_client_port *new_port, *p;
117 int num = -1;
118
119 /* sanity check */
120 if (snd_BUG_ON(!client))
121 return NULL;
122
123 if (client->num_ports >= SNDRV_SEQ_MAX_PORTS) {
124 pr_warn("ALSA: seq: too many ports for client %d\n", client->number);
125 return NULL;
126 }
127
128 /* create a new port */
129 new_port = kzalloc(sizeof(*new_port), GFP_KERNEL);
130 if (!new_port)
131 return NULL; /* failure, out of memory */
132 /* init port data */
133 new_port->addr.client = client->number;
134 new_port->addr.port = -1;
135 new_port->owner = THIS_MODULE;
136 sprintf(new_port->name, "port-%d", num);
137 snd_use_lock_init(&new_port->use_lock);
138 port_subs_info_init(&new_port->c_src);
139 port_subs_info_init(&new_port->c_dest);
140 snd_use_lock_use(&new_port->use_lock);
141
142 num = port >= 0 ? port : 0;
143 mutex_lock(&client->ports_mutex);
144 write_lock_irq(&client->ports_lock);
145 list_for_each_entry(p, &client->ports_list_head, list) {
146 if (p->addr.port > num)
147 break;
148 if (port < 0) /* auto-probe mode */
149 num = p->addr.port + 1;
150 }
151 /* insert the new port */
152 list_add_tail(&new_port->list, &p->list);
153 client->num_ports++;
154 new_port->addr.port = num; /* store the port number in the port */
155 sprintf(new_port->name, "port-%d", num);
156 write_unlock_irq(&client->ports_lock);
157 mutex_unlock(&client->ports_mutex);
158
159 return new_port;
160}
161
162/* */
163static int subscribe_port(struct snd_seq_client *client,
164 struct snd_seq_client_port *port,
165 struct snd_seq_port_subs_info *grp,
166 struct snd_seq_port_subscribe *info, int send_ack);
167static int unsubscribe_port(struct snd_seq_client *client,
168 struct snd_seq_client_port *port,
169 struct snd_seq_port_subs_info *grp,
170 struct snd_seq_port_subscribe *info, int send_ack);
171
172
173static struct snd_seq_client_port *get_client_port(struct snd_seq_addr *addr,
174 struct snd_seq_client **cp)
175{
176 struct snd_seq_client_port *p;
177 *cp = snd_seq_client_use_ptr(addr->client);
178 if (*cp) {
179 p = snd_seq_port_use_ptr(*cp, addr->port);
180 if (! p) {
181 snd_seq_client_unlock(*cp);
182 *cp = NULL;
183 }
184 return p;
185 }
186 return NULL;
187}
188
189static void delete_and_unsubscribe_port(struct snd_seq_client *client,
190 struct snd_seq_client_port *port,
191 struct snd_seq_subscribers *subs,
192 bool is_src, bool ack);
193
194static inline struct snd_seq_subscribers *
195get_subscriber(struct list_head *p, bool is_src)
196{
197 if (is_src)
198 return list_entry(p, struct snd_seq_subscribers, src_list);
199 else
200 return list_entry(p, struct snd_seq_subscribers, dest_list);
201}
202
203/*
204 * remove all subscribers on the list
205 * this is called from port_delete, for each src and dest list.
206 */
207static void clear_subscriber_list(struct snd_seq_client *client,
208 struct snd_seq_client_port *port,
209 struct snd_seq_port_subs_info *grp,
210 int is_src)
211{
212 struct list_head *p, *n;
213
214 list_for_each_safe(p, n, &grp->list_head) {
215 struct snd_seq_subscribers *subs;
216 struct snd_seq_client *c;
217 struct snd_seq_client_port *aport;
218
219 subs = get_subscriber(p, is_src);
220 if (is_src)
221 aport = get_client_port(&subs->info.dest, &c);
222 else
223 aport = get_client_port(&subs->info.sender, &c);
224 delete_and_unsubscribe_port(client, port, subs, is_src, false);
225
226 if (!aport) {
227 /* looks like the connected port is being deleted.
228 * we decrease the counter, and when both ports are deleted
229 * remove the subscriber info
230 */
231 if (atomic_dec_and_test(&subs->ref_count))
232 kfree(subs);
233 continue;
234 }
235
236 /* ok we got the connected port */
237 delete_and_unsubscribe_port(c, aport, subs, !is_src, true);
238 kfree(subs);
239 snd_seq_port_unlock(aport);
240 snd_seq_client_unlock(c);
241 }
242}
243
244/* delete port data */
245static int port_delete(struct snd_seq_client *client,
246 struct snd_seq_client_port *port)
247{
248 /* set closing flag and wait for all port access are gone */
249 port->closing = 1;
250 snd_use_lock_sync(&port->use_lock);
251
252 /* clear subscribers info */
253 clear_subscriber_list(client, port, &port->c_src, true);
254 clear_subscriber_list(client, port, &port->c_dest, false);
255
256 if (port->private_free)
257 port->private_free(port->private_data);
258
259 snd_BUG_ON(port->c_src.count != 0);
260 snd_BUG_ON(port->c_dest.count != 0);
261
262 kfree(port);
263 return 0;
264}
265
266
267/* delete a port with the given port id */
268int snd_seq_delete_port(struct snd_seq_client *client, int port)
269{
270 struct snd_seq_client_port *found = NULL, *p;
271
272 mutex_lock(&client->ports_mutex);
273 write_lock_irq(&client->ports_lock);
274 list_for_each_entry(p, &client->ports_list_head, list) {
275 if (p->addr.port == port) {
276 /* ok found. delete from the list at first */
277 list_del(&p->list);
278 client->num_ports--;
279 found = p;
280 break;
281 }
282 }
283 write_unlock_irq(&client->ports_lock);
284 mutex_unlock(&client->ports_mutex);
285 if (found)
286 return port_delete(client, found);
287 else
288 return -ENOENT;
289}
290
291/* delete the all ports belonging to the given client */
292int snd_seq_delete_all_ports(struct snd_seq_client *client)
293{
294 struct list_head deleted_list;
295 struct snd_seq_client_port *port, *tmp;
296
297 /* move the port list to deleted_list, and
298 * clear the port list in the client data.
299 */
300 mutex_lock(&client->ports_mutex);
301 write_lock_irq(&client->ports_lock);
302 if (! list_empty(&client->ports_list_head)) {
303 list_add(&deleted_list, &client->ports_list_head);
304 list_del_init(&client->ports_list_head);
305 } else {
306 INIT_LIST_HEAD(&deleted_list);
307 }
308 client->num_ports = 0;
309 write_unlock_irq(&client->ports_lock);
310
311 /* remove each port in deleted_list */
312 list_for_each_entry_safe(port, tmp, &deleted_list, list) {
313 list_del(&port->list);
314 snd_seq_system_client_ev_port_exit(port->addr.client, port->addr.port);
315 port_delete(client, port);
316 }
317 mutex_unlock(&client->ports_mutex);
318 return 0;
319}
320
321/* set port info fields */
322int snd_seq_set_port_info(struct snd_seq_client_port * port,
323 struct snd_seq_port_info * info)
324{
325 if (snd_BUG_ON(!port || !info))
326 return -EINVAL;
327
328 /* set port name */
329 if (info->name[0])
330 strlcpy(port->name, info->name, sizeof(port->name));
331
332 /* set capabilities */
333 port->capability = info->capability;
334
335 /* get port type */
336 port->type = info->type;
337
338 /* information about supported channels/voices */
339 port->midi_channels = info->midi_channels;
340 port->midi_voices = info->midi_voices;
341 port->synth_voices = info->synth_voices;
342
343 /* timestamping */
344 port->timestamping = (info->flags & SNDRV_SEQ_PORT_FLG_TIMESTAMP) ? 1 : 0;
345 port->time_real = (info->flags & SNDRV_SEQ_PORT_FLG_TIME_REAL) ? 1 : 0;
346 port->time_queue = info->time_queue;
347
348 return 0;
349}
350
351/* get port info fields */
352int snd_seq_get_port_info(struct snd_seq_client_port * port,
353 struct snd_seq_port_info * info)
354{
355 if (snd_BUG_ON(!port || !info))
356 return -EINVAL;
357
358 /* get port name */
359 strlcpy(info->name, port->name, sizeof(info->name));
360
361 /* get capabilities */
362 info->capability = port->capability;
363
364 /* get port type */
365 info->type = port->type;
366
367 /* information about supported channels/voices */
368 info->midi_channels = port->midi_channels;
369 info->midi_voices = port->midi_voices;
370 info->synth_voices = port->synth_voices;
371
372 /* get subscriber counts */
373 info->read_use = port->c_src.count;
374 info->write_use = port->c_dest.count;
375
376 /* timestamping */
377 info->flags = 0;
378 if (port->timestamping) {
379 info->flags |= SNDRV_SEQ_PORT_FLG_TIMESTAMP;
380 if (port->time_real)
381 info->flags |= SNDRV_SEQ_PORT_FLG_TIME_REAL;
382 info->time_queue = port->time_queue;
383 }
384
385 return 0;
386}
387
388
389
390/*
391 * call callback functions (if any):
392 * the callbacks are invoked only when the first (for connection) or
393 * the last subscription (for disconnection) is done. Second or later
394 * subscription results in increment of counter, but no callback is
395 * invoked.
396 * This feature is useful if these callbacks are associated with
397 * initialization or termination of devices (see seq_midi.c).
398 */
399
400static int subscribe_port(struct snd_seq_client *client,
401 struct snd_seq_client_port *port,
402 struct snd_seq_port_subs_info *grp,
403 struct snd_seq_port_subscribe *info,
404 int send_ack)
405{
406 int err = 0;
407
408 if (!try_module_get(port->owner))
409 return -EFAULT;
410 grp->count++;
411 if (grp->open && grp->count == 1) {
412 err = grp->open(port->private_data, info);
413 if (err < 0) {
414 module_put(port->owner);
415 grp->count--;
416 }
417 }
418 if (err >= 0 && send_ack && client->type == USER_CLIENT)
419 snd_seq_client_notify_subscription(port->addr.client, port->addr.port,
420 info, SNDRV_SEQ_EVENT_PORT_SUBSCRIBED);
421
422 return err;
423}
424
425static int unsubscribe_port(struct snd_seq_client *client,
426 struct snd_seq_client_port *port,
427 struct snd_seq_port_subs_info *grp,
428 struct snd_seq_port_subscribe *info,
429 int send_ack)
430{
431 int err = 0;
432
433 if (! grp->count)
434 return -EINVAL;
435 grp->count--;
436 if (grp->close && grp->count == 0)
437 err = grp->close(port->private_data, info);
438 if (send_ack && client->type == USER_CLIENT)
439 snd_seq_client_notify_subscription(port->addr.client, port->addr.port,
440 info, SNDRV_SEQ_EVENT_PORT_UNSUBSCRIBED);
441 module_put(port->owner);
442 return err;
443}
444
445
446
447/* check if both addresses are identical */
448static inline int addr_match(struct snd_seq_addr *r, struct snd_seq_addr *s)
449{
450 return (r->client == s->client) && (r->port == s->port);
451}
452
453/* check the two subscribe info match */
454/* if flags is zero, checks only sender and destination addresses */
455static int match_subs_info(struct snd_seq_port_subscribe *r,
456 struct snd_seq_port_subscribe *s)
457{
458 if (addr_match(&r->sender, &s->sender) &&
459 addr_match(&r->dest, &s->dest)) {
460 if (r->flags && r->flags == s->flags)
461 return r->queue == s->queue;
462 else if (! r->flags)
463 return 1;
464 }
465 return 0;
466}
467
468static int check_and_subscribe_port(struct snd_seq_client *client,
469 struct snd_seq_client_port *port,
470 struct snd_seq_subscribers *subs,
471 bool is_src, bool exclusive, bool ack)
472{
473 struct snd_seq_port_subs_info *grp;
474 struct list_head *p;
475 struct snd_seq_subscribers *s;
476 int err;
477
478 grp = is_src ? &port->c_src : &port->c_dest;
479 err = -EBUSY;
480 down_write(&grp->list_mutex);
481 if (exclusive) {
482 if (!list_empty(&grp->list_head))
483 goto __error;
484 } else {
485 if (grp->exclusive)
486 goto __error;
487 /* check whether already exists */
488 list_for_each(p, &grp->list_head) {
489 s = get_subscriber(p, is_src);
490 if (match_subs_info(&subs->info, &s->info))
491 goto __error;
492 }
493 }
494
495 err = subscribe_port(client, port, grp, &subs->info, ack);
496 if (err < 0) {
497 grp->exclusive = 0;
498 goto __error;
499 }
500
501 /* add to list */
502 write_lock_irq(&grp->list_lock);
503 if (is_src)
504 list_add_tail(&subs->src_list, &grp->list_head);
505 else
506 list_add_tail(&subs->dest_list, &grp->list_head);
507 grp->exclusive = exclusive;
508 atomic_inc(&subs->ref_count);
509 write_unlock_irq(&grp->list_lock);
510 err = 0;
511
512 __error:
513 up_write(&grp->list_mutex);
514 return err;
515}
516
517static void delete_and_unsubscribe_port(struct snd_seq_client *client,
518 struct snd_seq_client_port *port,
519 struct snd_seq_subscribers *subs,
520 bool is_src, bool ack)
521{
522 struct snd_seq_port_subs_info *grp;
523 struct list_head *list;
524 bool empty;
525
526 grp = is_src ? &port->c_src : &port->c_dest;
527 list = is_src ? &subs->src_list : &subs->dest_list;
528 down_write(&grp->list_mutex);
529 write_lock_irq(&grp->list_lock);
530 empty = list_empty(list);
531 if (!empty)
532 list_del_init(list);
533 grp->exclusive = 0;
534 write_unlock_irq(&grp->list_lock);
535
536 if (!empty)
537 unsubscribe_port(client, port, grp, &subs->info, ack);
538 up_write(&grp->list_mutex);
539}
540
541/* connect two ports */
542int snd_seq_port_connect(struct snd_seq_client *connector,
543 struct snd_seq_client *src_client,
544 struct snd_seq_client_port *src_port,
545 struct snd_seq_client *dest_client,
546 struct snd_seq_client_port *dest_port,
547 struct snd_seq_port_subscribe *info)
548{
549 struct snd_seq_subscribers *subs;
550 bool exclusive;
551 int err;
552
553 subs = kzalloc(sizeof(*subs), GFP_KERNEL);
554 if (!subs)
555 return -ENOMEM;
556
557 subs->info = *info;
558 atomic_set(&subs->ref_count, 0);
559 INIT_LIST_HEAD(&subs->src_list);
560 INIT_LIST_HEAD(&subs->dest_list);
561
562 exclusive = !!(info->flags & SNDRV_SEQ_PORT_SUBS_EXCLUSIVE);
563
564 err = check_and_subscribe_port(src_client, src_port, subs, true,
565 exclusive,
566 connector->number != src_client->number);
567 if (err < 0)
568 goto error;
569 err = check_and_subscribe_port(dest_client, dest_port, subs, false,
570 exclusive,
571 connector->number != dest_client->number);
572 if (err < 0)
573 goto error_dest;
574
575 return 0;
576
577 error_dest:
578 delete_and_unsubscribe_port(src_client, src_port, subs, true,
579 connector->number != src_client->number);
580 error:
581 kfree(subs);
582 return err;
583}
584
585/* remove the connection */
586int snd_seq_port_disconnect(struct snd_seq_client *connector,
587 struct snd_seq_client *src_client,
588 struct snd_seq_client_port *src_port,
589 struct snd_seq_client *dest_client,
590 struct snd_seq_client_port *dest_port,
591 struct snd_seq_port_subscribe *info)
592{
593 struct snd_seq_port_subs_info *src = &src_port->c_src;
594 struct snd_seq_subscribers *subs;
595 int err = -ENOENT;
596
597 down_write(&src->list_mutex);
598 /* look for the connection */
599 list_for_each_entry(subs, &src->list_head, src_list) {
600 if (match_subs_info(info, &subs->info)) {
601 atomic_dec(&subs->ref_count); /* mark as not ready */
602 err = 0;
603 break;
604 }
605 }
606 up_write(&src->list_mutex);
607 if (err < 0)
608 return err;
609
610 delete_and_unsubscribe_port(src_client, src_port, subs, true,
611 connector->number != src_client->number);
612 delete_and_unsubscribe_port(dest_client, dest_port, subs, false,
613 connector->number != dest_client->number);
614 kfree(subs);
615 return 0;
616}
617
618
619/* get matched subscriber */
620int snd_seq_port_get_subscription(struct snd_seq_port_subs_info *src_grp,
621 struct snd_seq_addr *dest_addr,
622 struct snd_seq_port_subscribe *subs)
623{
624 struct snd_seq_subscribers *s;
625 int err = -ENOENT;
626
627 down_read(&src_grp->list_mutex);
628 list_for_each_entry(s, &src_grp->list_head, src_list) {
629 if (addr_match(dest_addr, &s->info.dest)) {
630 *subs = s->info;
631 err = 0;
632 break;
633 }
634 }
635 up_read(&src_grp->list_mutex);
636 return err;
637}
638
639/*
640 * Attach a device driver that wants to receive events from the
641 * sequencer. Returns the new port number on success.
642 * A driver that wants to receive the events converted to midi, will
643 * use snd_seq_midisynth_register_port().
644 */
645/* exported */
646int snd_seq_event_port_attach(int client,
647 struct snd_seq_port_callback *pcbp,
648 int cap, int type, int midi_channels,
649 int midi_voices, char *portname)
650{
651 struct snd_seq_port_info portinfo;
652 int ret;
653
654 /* Set up the port */
655 memset(&portinfo, 0, sizeof(portinfo));
656 portinfo.addr.client = client;
657 strlcpy(portinfo.name, portname ? portname : "Unnamed port",
658 sizeof(portinfo.name));
659
660 portinfo.capability = cap;
661 portinfo.type = type;
662 portinfo.kernel = pcbp;
663 portinfo.midi_channels = midi_channels;
664 portinfo.midi_voices = midi_voices;
665
666 /* Create it */
667 ret = snd_seq_kernel_client_ctl(client,
668 SNDRV_SEQ_IOCTL_CREATE_PORT,
669 &portinfo);
670
671 if (ret >= 0)
672 ret = portinfo.addr.port;
673
674 return ret;
675}
676EXPORT_SYMBOL(snd_seq_event_port_attach);
677
678/*
679 * Detach the driver from a port.
680 */
681/* exported */
682int snd_seq_event_port_detach(int client, int port)
683{
684 struct snd_seq_port_info portinfo;
685 int err;
686
687 memset(&portinfo, 0, sizeof(portinfo));
688 portinfo.addr.client = client;
689 portinfo.addr.port = port;
690 err = snd_seq_kernel_client_ctl(client,
691 SNDRV_SEQ_IOCTL_DELETE_PORT,
692 &portinfo);
693
694 return err;
695}
696EXPORT_SYMBOL(snd_seq_event_port_detach);
1/*
2 * ALSA sequencer Ports
3 * Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
4 * Jaroslav Kysela <perex@perex.cz>
5 *
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 *
21 */
22
23#include <sound/core.h>
24#include <linux/slab.h>
25#include <linux/module.h>
26#include "seq_system.h"
27#include "seq_ports.h"
28#include "seq_clientmgr.h"
29
30/*
31
32 registration of client ports
33
34 */
35
36
37/*
38
39NOTE: the current implementation of the port structure as a linked list is
40not optimal for clients that have many ports. For sending messages to all
41subscribers of a port we first need to find the address of the port
42structure, which means we have to traverse the list. A direct access table
43(array) would be better, but big preallocated arrays waste memory.
44
45Possible actions:
46
471) leave it this way, a client does normaly does not have more than a few
48ports
49
502) replace the linked list of ports by a array of pointers which is
51dynamicly kmalloced. When a port is added or deleted we can simply allocate
52a new array, copy the corresponding pointers, and delete the old one. We
53then only need a pointer to this array, and an integer that tells us how
54much elements are in array.
55
56*/
57
58/* return pointer to port structure - port is locked if found */
59struct snd_seq_client_port *snd_seq_port_use_ptr(struct snd_seq_client *client,
60 int num)
61{
62 struct snd_seq_client_port *port;
63
64 if (client == NULL)
65 return NULL;
66 read_lock(&client->ports_lock);
67 list_for_each_entry(port, &client->ports_list_head, list) {
68 if (port->addr.port == num) {
69 if (port->closing)
70 break; /* deleting now */
71 snd_use_lock_use(&port->use_lock);
72 read_unlock(&client->ports_lock);
73 return port;
74 }
75 }
76 read_unlock(&client->ports_lock);
77 return NULL; /* not found */
78}
79
80
81/* search for the next port - port is locked if found */
82struct snd_seq_client_port *snd_seq_port_query_nearest(struct snd_seq_client *client,
83 struct snd_seq_port_info *pinfo)
84{
85 int num;
86 struct snd_seq_client_port *port, *found;
87
88 num = pinfo->addr.port;
89 found = NULL;
90 read_lock(&client->ports_lock);
91 list_for_each_entry(port, &client->ports_list_head, list) {
92 if (port->addr.port < num)
93 continue;
94 if (port->addr.port == num) {
95 found = port;
96 break;
97 }
98 if (found == NULL || port->addr.port < found->addr.port)
99 found = port;
100 }
101 if (found) {
102 if (found->closing)
103 found = NULL;
104 else
105 snd_use_lock_use(&found->use_lock);
106 }
107 read_unlock(&client->ports_lock);
108 return found;
109}
110
111
112/* initialize snd_seq_port_subs_info */
113static void port_subs_info_init(struct snd_seq_port_subs_info *grp)
114{
115 INIT_LIST_HEAD(&grp->list_head);
116 grp->count = 0;
117 grp->exclusive = 0;
118 rwlock_init(&grp->list_lock);
119 init_rwsem(&grp->list_mutex);
120 grp->open = NULL;
121 grp->close = NULL;
122}
123
124
125/* create a port, port number is returned (-1 on failure) */
126struct snd_seq_client_port *snd_seq_create_port(struct snd_seq_client *client,
127 int port)
128{
129 unsigned long flags;
130 struct snd_seq_client_port *new_port, *p;
131 int num = -1;
132
133 /* sanity check */
134 if (snd_BUG_ON(!client))
135 return NULL;
136
137 if (client->num_ports >= SNDRV_SEQ_MAX_PORTS) {
138 pr_warn("ALSA: seq: too many ports for client %d\n", client->number);
139 return NULL;
140 }
141
142 /* create a new port */
143 new_port = kzalloc(sizeof(*new_port), GFP_KERNEL);
144 if (!new_port)
145 return NULL; /* failure, out of memory */
146 /* init port data */
147 new_port->addr.client = client->number;
148 new_port->addr.port = -1;
149 new_port->owner = THIS_MODULE;
150 sprintf(new_port->name, "port-%d", num);
151 snd_use_lock_init(&new_port->use_lock);
152 port_subs_info_init(&new_port->c_src);
153 port_subs_info_init(&new_port->c_dest);
154
155 num = port >= 0 ? port : 0;
156 mutex_lock(&client->ports_mutex);
157 write_lock_irqsave(&client->ports_lock, flags);
158 list_for_each_entry(p, &client->ports_list_head, list) {
159 if (p->addr.port > num)
160 break;
161 if (port < 0) /* auto-probe mode */
162 num = p->addr.port + 1;
163 }
164 /* insert the new port */
165 list_add_tail(&new_port->list, &p->list);
166 client->num_ports++;
167 new_port->addr.port = num; /* store the port number in the port */
168 write_unlock_irqrestore(&client->ports_lock, flags);
169 mutex_unlock(&client->ports_mutex);
170 sprintf(new_port->name, "port-%d", num);
171
172 return new_port;
173}
174
175/* */
176static int subscribe_port(struct snd_seq_client *client,
177 struct snd_seq_client_port *port,
178 struct snd_seq_port_subs_info *grp,
179 struct snd_seq_port_subscribe *info, int send_ack);
180static int unsubscribe_port(struct snd_seq_client *client,
181 struct snd_seq_client_port *port,
182 struct snd_seq_port_subs_info *grp,
183 struct snd_seq_port_subscribe *info, int send_ack);
184
185
186static struct snd_seq_client_port *get_client_port(struct snd_seq_addr *addr,
187 struct snd_seq_client **cp)
188{
189 struct snd_seq_client_port *p;
190 *cp = snd_seq_client_use_ptr(addr->client);
191 if (*cp) {
192 p = snd_seq_port_use_ptr(*cp, addr->port);
193 if (! p) {
194 snd_seq_client_unlock(*cp);
195 *cp = NULL;
196 }
197 return p;
198 }
199 return NULL;
200}
201
202static void delete_and_unsubscribe_port(struct snd_seq_client *client,
203 struct snd_seq_client_port *port,
204 struct snd_seq_subscribers *subs,
205 bool is_src, bool ack);
206
207static inline struct snd_seq_subscribers *
208get_subscriber(struct list_head *p, bool is_src)
209{
210 if (is_src)
211 return list_entry(p, struct snd_seq_subscribers, src_list);
212 else
213 return list_entry(p, struct snd_seq_subscribers, dest_list);
214}
215
216/*
217 * remove all subscribers on the list
218 * this is called from port_delete, for each src and dest list.
219 */
220static void clear_subscriber_list(struct snd_seq_client *client,
221 struct snd_seq_client_port *port,
222 struct snd_seq_port_subs_info *grp,
223 int is_src)
224{
225 struct list_head *p, *n;
226
227 list_for_each_safe(p, n, &grp->list_head) {
228 struct snd_seq_subscribers *subs;
229 struct snd_seq_client *c;
230 struct snd_seq_client_port *aport;
231
232 subs = get_subscriber(p, is_src);
233 if (is_src)
234 aport = get_client_port(&subs->info.dest, &c);
235 else
236 aport = get_client_port(&subs->info.sender, &c);
237 delete_and_unsubscribe_port(client, port, subs, is_src, false);
238
239 if (!aport) {
240 /* looks like the connected port is being deleted.
241 * we decrease the counter, and when both ports are deleted
242 * remove the subscriber info
243 */
244 if (atomic_dec_and_test(&subs->ref_count))
245 kfree(subs);
246 continue;
247 }
248
249 /* ok we got the connected port */
250 delete_and_unsubscribe_port(c, aport, subs, !is_src, true);
251 kfree(subs);
252 snd_seq_port_unlock(aport);
253 snd_seq_client_unlock(c);
254 }
255}
256
257/* delete port data */
258static int port_delete(struct snd_seq_client *client,
259 struct snd_seq_client_port *port)
260{
261 /* set closing flag and wait for all port access are gone */
262 port->closing = 1;
263 snd_use_lock_sync(&port->use_lock);
264
265 /* clear subscribers info */
266 clear_subscriber_list(client, port, &port->c_src, true);
267 clear_subscriber_list(client, port, &port->c_dest, false);
268
269 if (port->private_free)
270 port->private_free(port->private_data);
271
272 snd_BUG_ON(port->c_src.count != 0);
273 snd_BUG_ON(port->c_dest.count != 0);
274
275 kfree(port);
276 return 0;
277}
278
279
280/* delete a port with the given port id */
281int snd_seq_delete_port(struct snd_seq_client *client, int port)
282{
283 unsigned long flags;
284 struct snd_seq_client_port *found = NULL, *p;
285
286 mutex_lock(&client->ports_mutex);
287 write_lock_irqsave(&client->ports_lock, flags);
288 list_for_each_entry(p, &client->ports_list_head, list) {
289 if (p->addr.port == port) {
290 /* ok found. delete from the list at first */
291 list_del(&p->list);
292 client->num_ports--;
293 found = p;
294 break;
295 }
296 }
297 write_unlock_irqrestore(&client->ports_lock, flags);
298 mutex_unlock(&client->ports_mutex);
299 if (found)
300 return port_delete(client, found);
301 else
302 return -ENOENT;
303}
304
305/* delete the all ports belonging to the given client */
306int snd_seq_delete_all_ports(struct snd_seq_client *client)
307{
308 unsigned long flags;
309 struct list_head deleted_list;
310 struct snd_seq_client_port *port, *tmp;
311
312 /* move the port list to deleted_list, and
313 * clear the port list in the client data.
314 */
315 mutex_lock(&client->ports_mutex);
316 write_lock_irqsave(&client->ports_lock, flags);
317 if (! list_empty(&client->ports_list_head)) {
318 list_add(&deleted_list, &client->ports_list_head);
319 list_del_init(&client->ports_list_head);
320 } else {
321 INIT_LIST_HEAD(&deleted_list);
322 }
323 client->num_ports = 0;
324 write_unlock_irqrestore(&client->ports_lock, flags);
325
326 /* remove each port in deleted_list */
327 list_for_each_entry_safe(port, tmp, &deleted_list, list) {
328 list_del(&port->list);
329 snd_seq_system_client_ev_port_exit(port->addr.client, port->addr.port);
330 port_delete(client, port);
331 }
332 mutex_unlock(&client->ports_mutex);
333 return 0;
334}
335
336/* set port info fields */
337int snd_seq_set_port_info(struct snd_seq_client_port * port,
338 struct snd_seq_port_info * info)
339{
340 if (snd_BUG_ON(!port || !info))
341 return -EINVAL;
342
343 /* set port name */
344 if (info->name[0])
345 strlcpy(port->name, info->name, sizeof(port->name));
346
347 /* set capabilities */
348 port->capability = info->capability;
349
350 /* get port type */
351 port->type = info->type;
352
353 /* information about supported channels/voices */
354 port->midi_channels = info->midi_channels;
355 port->midi_voices = info->midi_voices;
356 port->synth_voices = info->synth_voices;
357
358 /* timestamping */
359 port->timestamping = (info->flags & SNDRV_SEQ_PORT_FLG_TIMESTAMP) ? 1 : 0;
360 port->time_real = (info->flags & SNDRV_SEQ_PORT_FLG_TIME_REAL) ? 1 : 0;
361 port->time_queue = info->time_queue;
362
363 return 0;
364}
365
366/* get port info fields */
367int snd_seq_get_port_info(struct snd_seq_client_port * port,
368 struct snd_seq_port_info * info)
369{
370 if (snd_BUG_ON(!port || !info))
371 return -EINVAL;
372
373 /* get port name */
374 strlcpy(info->name, port->name, sizeof(info->name));
375
376 /* get capabilities */
377 info->capability = port->capability;
378
379 /* get port type */
380 info->type = port->type;
381
382 /* information about supported channels/voices */
383 info->midi_channels = port->midi_channels;
384 info->midi_voices = port->midi_voices;
385 info->synth_voices = port->synth_voices;
386
387 /* get subscriber counts */
388 info->read_use = port->c_src.count;
389 info->write_use = port->c_dest.count;
390
391 /* timestamping */
392 info->flags = 0;
393 if (port->timestamping) {
394 info->flags |= SNDRV_SEQ_PORT_FLG_TIMESTAMP;
395 if (port->time_real)
396 info->flags |= SNDRV_SEQ_PORT_FLG_TIME_REAL;
397 info->time_queue = port->time_queue;
398 }
399
400 return 0;
401}
402
403
404
405/*
406 * call callback functions (if any):
407 * the callbacks are invoked only when the first (for connection) or
408 * the last subscription (for disconnection) is done. Second or later
409 * subscription results in increment of counter, but no callback is
410 * invoked.
411 * This feature is useful if these callbacks are associated with
412 * initialization or termination of devices (see seq_midi.c).
413 */
414
415static int subscribe_port(struct snd_seq_client *client,
416 struct snd_seq_client_port *port,
417 struct snd_seq_port_subs_info *grp,
418 struct snd_seq_port_subscribe *info,
419 int send_ack)
420{
421 int err = 0;
422
423 if (!try_module_get(port->owner))
424 return -EFAULT;
425 grp->count++;
426 if (grp->open && grp->count == 1) {
427 err = grp->open(port->private_data, info);
428 if (err < 0) {
429 module_put(port->owner);
430 grp->count--;
431 }
432 }
433 if (err >= 0 && send_ack && client->type == USER_CLIENT)
434 snd_seq_client_notify_subscription(port->addr.client, port->addr.port,
435 info, SNDRV_SEQ_EVENT_PORT_SUBSCRIBED);
436
437 return err;
438}
439
440static int unsubscribe_port(struct snd_seq_client *client,
441 struct snd_seq_client_port *port,
442 struct snd_seq_port_subs_info *grp,
443 struct snd_seq_port_subscribe *info,
444 int send_ack)
445{
446 int err = 0;
447
448 if (! grp->count)
449 return -EINVAL;
450 grp->count--;
451 if (grp->close && grp->count == 0)
452 err = grp->close(port->private_data, info);
453 if (send_ack && client->type == USER_CLIENT)
454 snd_seq_client_notify_subscription(port->addr.client, port->addr.port,
455 info, SNDRV_SEQ_EVENT_PORT_UNSUBSCRIBED);
456 module_put(port->owner);
457 return err;
458}
459
460
461
462/* check if both addresses are identical */
463static inline int addr_match(struct snd_seq_addr *r, struct snd_seq_addr *s)
464{
465 return (r->client == s->client) && (r->port == s->port);
466}
467
468/* check the two subscribe info match */
469/* if flags is zero, checks only sender and destination addresses */
470static int match_subs_info(struct snd_seq_port_subscribe *r,
471 struct snd_seq_port_subscribe *s)
472{
473 if (addr_match(&r->sender, &s->sender) &&
474 addr_match(&r->dest, &s->dest)) {
475 if (r->flags && r->flags == s->flags)
476 return r->queue == s->queue;
477 else if (! r->flags)
478 return 1;
479 }
480 return 0;
481}
482
483static int check_and_subscribe_port(struct snd_seq_client *client,
484 struct snd_seq_client_port *port,
485 struct snd_seq_subscribers *subs,
486 bool is_src, bool exclusive, bool ack)
487{
488 struct snd_seq_port_subs_info *grp;
489 struct list_head *p;
490 struct snd_seq_subscribers *s;
491 int err;
492
493 grp = is_src ? &port->c_src : &port->c_dest;
494 err = -EBUSY;
495 down_write(&grp->list_mutex);
496 if (exclusive) {
497 if (!list_empty(&grp->list_head))
498 goto __error;
499 } else {
500 if (grp->exclusive)
501 goto __error;
502 /* check whether already exists */
503 list_for_each(p, &grp->list_head) {
504 s = get_subscriber(p, is_src);
505 if (match_subs_info(&subs->info, &s->info))
506 goto __error;
507 }
508 }
509
510 err = subscribe_port(client, port, grp, &subs->info, ack);
511 if (err < 0) {
512 grp->exclusive = 0;
513 goto __error;
514 }
515
516 /* add to list */
517 write_lock_irq(&grp->list_lock);
518 if (is_src)
519 list_add_tail(&subs->src_list, &grp->list_head);
520 else
521 list_add_tail(&subs->dest_list, &grp->list_head);
522 grp->exclusive = exclusive;
523 atomic_inc(&subs->ref_count);
524 write_unlock_irq(&grp->list_lock);
525 err = 0;
526
527 __error:
528 up_write(&grp->list_mutex);
529 return err;
530}
531
532static void delete_and_unsubscribe_port(struct snd_seq_client *client,
533 struct snd_seq_client_port *port,
534 struct snd_seq_subscribers *subs,
535 bool is_src, bool ack)
536{
537 struct snd_seq_port_subs_info *grp;
538 struct list_head *list;
539 bool empty;
540
541 grp = is_src ? &port->c_src : &port->c_dest;
542 list = is_src ? &subs->src_list : &subs->dest_list;
543 down_write(&grp->list_mutex);
544 write_lock_irq(&grp->list_lock);
545 empty = list_empty(list);
546 if (!empty)
547 list_del_init(list);
548 grp->exclusive = 0;
549 write_unlock_irq(&grp->list_lock);
550 up_write(&grp->list_mutex);
551
552 if (!empty)
553 unsubscribe_port(client, port, grp, &subs->info, ack);
554}
555
556/* connect two ports */
557int snd_seq_port_connect(struct snd_seq_client *connector,
558 struct snd_seq_client *src_client,
559 struct snd_seq_client_port *src_port,
560 struct snd_seq_client *dest_client,
561 struct snd_seq_client_port *dest_port,
562 struct snd_seq_port_subscribe *info)
563{
564 struct snd_seq_subscribers *subs;
565 bool exclusive;
566 int err;
567
568 subs = kzalloc(sizeof(*subs), GFP_KERNEL);
569 if (!subs)
570 return -ENOMEM;
571
572 subs->info = *info;
573 atomic_set(&subs->ref_count, 0);
574 INIT_LIST_HEAD(&subs->src_list);
575 INIT_LIST_HEAD(&subs->dest_list);
576
577 exclusive = !!(info->flags & SNDRV_SEQ_PORT_SUBS_EXCLUSIVE);
578
579 err = check_and_subscribe_port(src_client, src_port, subs, true,
580 exclusive,
581 connector->number != src_client->number);
582 if (err < 0)
583 goto error;
584 err = check_and_subscribe_port(dest_client, dest_port, subs, false,
585 exclusive,
586 connector->number != dest_client->number);
587 if (err < 0)
588 goto error_dest;
589
590 return 0;
591
592 error_dest:
593 delete_and_unsubscribe_port(src_client, src_port, subs, true,
594 connector->number != src_client->number);
595 error:
596 kfree(subs);
597 return err;
598}
599
600/* remove the connection */
601int snd_seq_port_disconnect(struct snd_seq_client *connector,
602 struct snd_seq_client *src_client,
603 struct snd_seq_client_port *src_port,
604 struct snd_seq_client *dest_client,
605 struct snd_seq_client_port *dest_port,
606 struct snd_seq_port_subscribe *info)
607{
608 struct snd_seq_port_subs_info *src = &src_port->c_src;
609 struct snd_seq_subscribers *subs;
610 int err = -ENOENT;
611
612 down_write(&src->list_mutex);
613 /* look for the connection */
614 list_for_each_entry(subs, &src->list_head, src_list) {
615 if (match_subs_info(info, &subs->info)) {
616 atomic_dec(&subs->ref_count); /* mark as not ready */
617 err = 0;
618 break;
619 }
620 }
621 up_write(&src->list_mutex);
622 if (err < 0)
623 return err;
624
625 delete_and_unsubscribe_port(src_client, src_port, subs, true,
626 connector->number != src_client->number);
627 delete_and_unsubscribe_port(dest_client, dest_port, subs, false,
628 connector->number != dest_client->number);
629 kfree(subs);
630 return 0;
631}
632
633
634/* get matched subscriber */
635struct snd_seq_subscribers *snd_seq_port_get_subscription(struct snd_seq_port_subs_info *src_grp,
636 struct snd_seq_addr *dest_addr)
637{
638 struct snd_seq_subscribers *s, *found = NULL;
639
640 down_read(&src_grp->list_mutex);
641 list_for_each_entry(s, &src_grp->list_head, src_list) {
642 if (addr_match(dest_addr, &s->info.dest)) {
643 found = s;
644 break;
645 }
646 }
647 up_read(&src_grp->list_mutex);
648 return found;
649}
650
651/*
652 * Attach a device driver that wants to receive events from the
653 * sequencer. Returns the new port number on success.
654 * A driver that wants to receive the events converted to midi, will
655 * use snd_seq_midisynth_register_port().
656 */
657/* exported */
658int snd_seq_event_port_attach(int client,
659 struct snd_seq_port_callback *pcbp,
660 int cap, int type, int midi_channels,
661 int midi_voices, char *portname)
662{
663 struct snd_seq_port_info portinfo;
664 int ret;
665
666 /* Set up the port */
667 memset(&portinfo, 0, sizeof(portinfo));
668 portinfo.addr.client = client;
669 strlcpy(portinfo.name, portname ? portname : "Unamed port",
670 sizeof(portinfo.name));
671
672 portinfo.capability = cap;
673 portinfo.type = type;
674 portinfo.kernel = pcbp;
675 portinfo.midi_channels = midi_channels;
676 portinfo.midi_voices = midi_voices;
677
678 /* Create it */
679 ret = snd_seq_kernel_client_ctl(client,
680 SNDRV_SEQ_IOCTL_CREATE_PORT,
681 &portinfo);
682
683 if (ret >= 0)
684 ret = portinfo.addr.port;
685
686 return ret;
687}
688
689EXPORT_SYMBOL(snd_seq_event_port_attach);
690
691/*
692 * Detach the driver from a port.
693 */
694/* exported */
695int snd_seq_event_port_detach(int client, int port)
696{
697 struct snd_seq_port_info portinfo;
698 int err;
699
700 memset(&portinfo, 0, sizeof(portinfo));
701 portinfo.addr.client = client;
702 portinfo.addr.port = port;
703 err = snd_seq_kernel_client_ctl(client,
704 SNDRV_SEQ_IOCTL_DELETE_PORT,
705 &portinfo);
706
707 return err;
708}
709
710EXPORT_SYMBOL(snd_seq_event_port_detach);