blob: a8c2822e01984ff207c8a46b5ebd67546ee8b2eb [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * ALSA sequencer FIFO
3 * Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
4 *
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <sound/core.h>
23#include <linux/slab.h>
Ingo Molnar174cd4b2017-02-02 19:15:33 +010024#include <linux/sched/signal.h>
25
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include "seq_fifo.h"
27#include "seq_lock.h"
28
29
30/* FIFO */
31
32/* create new fifo */
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +010033struct snd_seq_fifo *snd_seq_fifo_new(int poolsize)
Linus Torvalds1da177e2005-04-16 15:20:36 -070034{
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +010035 struct snd_seq_fifo *f;
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
Takashi Iwaiecca82b2005-09-09 14:20:49 +020037 f = kzalloc(sizeof(*f), GFP_KERNEL);
Takashi Iwai24db8bb2015-03-10 15:41:18 +010038 if (!f)
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
41 f->pool = snd_seq_pool_new(poolsize);
42 if (f->pool == NULL) {
43 kfree(f);
44 return NULL;
45 }
46 if (snd_seq_pool_init(f->pool) < 0) {
47 snd_seq_pool_delete(&f->pool);
48 kfree(f);
49 return NULL;
50 }
51
52 spin_lock_init(&f->lock);
53 snd_use_lock_init(&f->use_lock);
54 init_waitqueue_head(&f->input_sleep);
55 atomic_set(&f->overflow, 0);
56
57 f->head = NULL;
58 f->tail = NULL;
59 f->cells = 0;
60
61 return f;
62}
63
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +010064void snd_seq_fifo_delete(struct snd_seq_fifo **fifo)
Linus Torvalds1da177e2005-04-16 15:20:36 -070065{
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +010066 struct snd_seq_fifo *f;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
Takashi Iwai7eaa9432008-08-08 17:09:09 +020068 if (snd_BUG_ON(!fifo))
69 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 f = *fifo;
Takashi Iwai7eaa9432008-08-08 17:09:09 +020071 if (snd_BUG_ON(!f))
72 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 *fifo = NULL;
74
Takashi Iwaic520ff32017-03-21 13:56:04 +010075 if (f->pool)
76 snd_seq_pool_mark_closing(f->pool);
77
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 snd_seq_fifo_clear(f);
79
80 /* wake up clients if any */
81 if (waitqueue_active(&f->input_sleep))
82 wake_up(&f->input_sleep);
83
84 /* release resources...*/
85 /*....................*/
86
87 if (f->pool) {
88 snd_seq_pool_done(f->pool);
89 snd_seq_pool_delete(&f->pool);
90 }
91
92 kfree(f);
93}
94
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +010095static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97/* clear queue */
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +010098void snd_seq_fifo_clear(struct snd_seq_fifo *f)
Linus Torvalds1da177e2005-04-16 15:20:36 -070099{
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +0100100 struct snd_seq_event_cell *cell;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 unsigned long flags;
102
103 /* clear overflow flag */
104 atomic_set(&f->overflow, 0);
105
106 snd_use_lock_sync(&f->use_lock);
107 spin_lock_irqsave(&f->lock, flags);
108 /* drain the fifo */
109 while ((cell = fifo_cell_out(f)) != NULL) {
110 snd_seq_cell_free(cell);
111 }
112 spin_unlock_irqrestore(&f->lock, flags);
113}
114
115
116/* enqueue event to fifo */
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +0100117int snd_seq_fifo_event_in(struct snd_seq_fifo *f,
118 struct snd_seq_event *event)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119{
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +0100120 struct snd_seq_event_cell *cell;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 unsigned long flags;
122 int err;
123
Takashi Iwai7eaa9432008-08-08 17:09:09 +0200124 if (snd_BUG_ON(!f))
125 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
127 snd_use_lock_use(&f->use_lock);
128 err = snd_seq_event_dup(f->pool, event, &cell, 1, NULL); /* always non-blocking */
129 if (err < 0) {
Adam Goode21fd3e92014-06-04 01:02:51 -0400130 if ((err == -ENOMEM) || (err == -EAGAIN))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 atomic_inc(&f->overflow);
132 snd_use_lock_free(&f->use_lock);
133 return err;
134 }
135
136 /* append new cells to fifo */
137 spin_lock_irqsave(&f->lock, flags);
138 if (f->tail != NULL)
139 f->tail->next = cell;
140 f->tail = cell;
141 if (f->head == NULL)
142 f->head = cell;
Takashi Iwaif3ac9f72017-02-28 22:15:51 +0100143 cell->next = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 f->cells++;
145 spin_unlock_irqrestore(&f->lock, flags);
146
147 /* wakeup client */
148 if (waitqueue_active(&f->input_sleep))
149 wake_up(&f->input_sleep);
150
151 snd_use_lock_free(&f->use_lock);
152
153 return 0; /* success */
154
155}
156
157/* dequeue cell from fifo */
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +0100158static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159{
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +0100160 struct snd_seq_event_cell *cell;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
162 if ((cell = f->head) != NULL) {
163 f->head = cell->next;
164
165 /* reset tail if this was the last element */
166 if (f->tail == cell)
167 f->tail = NULL;
168
169 cell->next = NULL;
170 f->cells--;
171 }
172
173 return cell;
174}
175
176/* dequeue cell from fifo and copy on user space */
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +0100177int snd_seq_fifo_cell_out(struct snd_seq_fifo *f,
178 struct snd_seq_event_cell **cellp, int nonblock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179{
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +0100180 struct snd_seq_event_cell *cell;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 unsigned long flags;
Ingo Molnarac6424b2017-06-20 12:06:13 +0200182 wait_queue_entry_t wait;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
Takashi Iwai7eaa9432008-08-08 17:09:09 +0200184 if (snd_BUG_ON(!f))
185 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186
187 *cellp = NULL;
188 init_waitqueue_entry(&wait, current);
189 spin_lock_irqsave(&f->lock, flags);
190 while ((cell = fifo_cell_out(f)) == NULL) {
191 if (nonblock) {
192 /* non-blocking - return immediately */
193 spin_unlock_irqrestore(&f->lock, flags);
194 return -EAGAIN;
195 }
196 set_current_state(TASK_INTERRUPTIBLE);
197 add_wait_queue(&f->input_sleep, &wait);
198 spin_unlock_irq(&f->lock);
199 schedule();
200 spin_lock_irq(&f->lock);
201 remove_wait_queue(&f->input_sleep, &wait);
202 if (signal_pending(current)) {
203 spin_unlock_irqrestore(&f->lock, flags);
204 return -ERESTARTSYS;
205 }
206 }
207 spin_unlock_irqrestore(&f->lock, flags);
208 *cellp = cell;
209
210 return 0;
211}
212
213
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +0100214void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f,
215 struct snd_seq_event_cell *cell)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216{
217 unsigned long flags;
218
219 if (cell) {
220 spin_lock_irqsave(&f->lock, flags);
221 cell->next = f->head;
222 f->head = cell;
Takashi Iwaif3ac9f72017-02-28 22:15:51 +0100223 if (!f->tail)
224 f->tail = cell;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 f->cells++;
226 spin_unlock_irqrestore(&f->lock, flags);
227 }
228}
229
230
231/* polling; return non-zero if queue is available */
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +0100232int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file,
233 poll_table *wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234{
235 poll_wait(file, &f->input_sleep, wait);
236 return (f->cells > 0);
237}
238
239/* change the size of pool; all old events are removed */
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +0100240int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241{
242 unsigned long flags;
Takashi Iwaic7e0b5b2005-11-17 14:04:02 +0100243 struct snd_seq_pool *newpool, *oldpool;
244 struct snd_seq_event_cell *cell, *next, *oldhead;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245
Takashi Iwai7eaa9432008-08-08 17:09:09 +0200246 if (snd_BUG_ON(!f || !f->pool))
247 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
249 /* allocate new pool */
250 newpool = snd_seq_pool_new(poolsize);
251 if (newpool == NULL)
252 return -ENOMEM;
253 if (snd_seq_pool_init(newpool) < 0) {
254 snd_seq_pool_delete(&newpool);
255 return -ENOMEM;
256 }
257
258 spin_lock_irqsave(&f->lock, flags);
259 /* remember old pool */
260 oldpool = f->pool;
261 oldhead = f->head;
262 /* exchange pools */
263 f->pool = newpool;
264 f->head = NULL;
265 f->tail = NULL;
266 f->cells = 0;
267 /* NOTE: overflow flag is not cleared */
268 spin_unlock_irqrestore(&f->lock, flags);
269
Takashi Iwai2d7d5402017-03-24 17:07:57 +0100270 /* close the old pool and wait until all users are gone */
271 snd_seq_pool_mark_closing(oldpool);
272 snd_use_lock_sync(&f->use_lock);
273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 /* release cells in old pool */
275 for (cell = oldhead; cell; cell = next) {
276 next = cell->next;
277 snd_seq_cell_free(cell);
278 }
279 snd_seq_pool_delete(&oldpool);
280
281 return 0;
282}