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1/*
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
22#include <sound/core.h>
23#include <linux/slab.h>
24#include "seq_fifo.h"
25#include "seq_lock.h"
26
27
28/* FIFO */
29
30/* create new fifo */
31struct snd_seq_fifo *snd_seq_fifo_new(int poolsize)
32{
33 struct snd_seq_fifo *f;
34
35 f = kzalloc(sizeof(*f), GFP_KERNEL);
36 if (f == NULL) {
37 pr_debug("ALSA: seq: malloc failed for snd_seq_fifo_new() \n");
38 return NULL;
39 }
40
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
64void snd_seq_fifo_delete(struct snd_seq_fifo **fifo)
65{
66 struct snd_seq_fifo *f;
67
68 if (snd_BUG_ON(!fifo))
69 return;
70 f = *fifo;
71 if (snd_BUG_ON(!f))
72 return;
73 *fifo = NULL;
74
75 snd_seq_fifo_clear(f);
76
77 /* wake up clients if any */
78 if (waitqueue_active(&f->input_sleep))
79 wake_up(&f->input_sleep);
80
81 /* release resources...*/
82 /*....................*/
83
84 if (f->pool) {
85 snd_seq_pool_done(f->pool);
86 snd_seq_pool_delete(&f->pool);
87 }
88
89 kfree(f);
90}
91
92static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f);
93
94/* clear queue */
95void snd_seq_fifo_clear(struct snd_seq_fifo *f)
96{
97 struct snd_seq_event_cell *cell;
98 unsigned long flags;
99
100 /* clear overflow flag */
101 atomic_set(&f->overflow, 0);
102
103 snd_use_lock_sync(&f->use_lock);
104 spin_lock_irqsave(&f->lock, flags);
105 /* drain the fifo */
106 while ((cell = fifo_cell_out(f)) != NULL) {
107 snd_seq_cell_free(cell);
108 }
109 spin_unlock_irqrestore(&f->lock, flags);
110}
111
112
113/* enqueue event to fifo */
114int snd_seq_fifo_event_in(struct snd_seq_fifo *f,
115 struct snd_seq_event *event)
116{
117 struct snd_seq_event_cell *cell;
118 unsigned long flags;
119 int err;
120
121 if (snd_BUG_ON(!f))
122 return -EINVAL;
123
124 snd_use_lock_use(&f->use_lock);
125 err = snd_seq_event_dup(f->pool, event, &cell, 1, NULL); /* always non-blocking */
126 if (err < 0) {
127 if (err == -ENOMEM)
128 atomic_inc(&f->overflow);
129 snd_use_lock_free(&f->use_lock);
130 return err;
131 }
132
133 /* append new cells to fifo */
134 spin_lock_irqsave(&f->lock, flags);
135 if (f->tail != NULL)
136 f->tail->next = cell;
137 f->tail = cell;
138 if (f->head == NULL)
139 f->head = cell;
140 f->cells++;
141 spin_unlock_irqrestore(&f->lock, flags);
142
143 /* wakeup client */
144 if (waitqueue_active(&f->input_sleep))
145 wake_up(&f->input_sleep);
146
147 snd_use_lock_free(&f->use_lock);
148
149 return 0; /* success */
150
151}
152
153/* dequeue cell from fifo */
154static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f)
155{
156 struct snd_seq_event_cell *cell;
157
158 if ((cell = f->head) != NULL) {
159 f->head = cell->next;
160
161 /* reset tail if this was the last element */
162 if (f->tail == cell)
163 f->tail = NULL;
164
165 cell->next = NULL;
166 f->cells--;
167 }
168
169 return cell;
170}
171
172/* dequeue cell from fifo and copy on user space */
173int snd_seq_fifo_cell_out(struct snd_seq_fifo *f,
174 struct snd_seq_event_cell **cellp, int nonblock)
175{
176 struct snd_seq_event_cell *cell;
177 unsigned long flags;
178 wait_queue_t wait;
179
180 if (snd_BUG_ON(!f))
181 return -EINVAL;
182
183 *cellp = NULL;
184 init_waitqueue_entry(&wait, current);
185 spin_lock_irqsave(&f->lock, flags);
186 while ((cell = fifo_cell_out(f)) == NULL) {
187 if (nonblock) {
188 /* non-blocking - return immediately */
189 spin_unlock_irqrestore(&f->lock, flags);
190 return -EAGAIN;
191 }
192 set_current_state(TASK_INTERRUPTIBLE);
193 add_wait_queue(&f->input_sleep, &wait);
194 spin_unlock_irq(&f->lock);
195 schedule();
196 spin_lock_irq(&f->lock);
197 remove_wait_queue(&f->input_sleep, &wait);
198 if (signal_pending(current)) {
199 spin_unlock_irqrestore(&f->lock, flags);
200 return -ERESTARTSYS;
201 }
202 }
203 spin_unlock_irqrestore(&f->lock, flags);
204 *cellp = cell;
205
206 return 0;
207}
208
209
210void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f,
211 struct snd_seq_event_cell *cell)
212{
213 unsigned long flags;
214
215 if (cell) {
216 spin_lock_irqsave(&f->lock, flags);
217 cell->next = f->head;
218 f->head = cell;
219 f->cells++;
220 spin_unlock_irqrestore(&f->lock, flags);
221 }
222}
223
224
225/* polling; return non-zero if queue is available */
226int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file,
227 poll_table *wait)
228{
229 poll_wait(file, &f->input_sleep, wait);
230 return (f->cells > 0);
231}
232
233/* change the size of pool; all old events are removed */
234int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize)
235{
236 unsigned long flags;
237 struct snd_seq_pool *newpool, *oldpool;
238 struct snd_seq_event_cell *cell, *next, *oldhead;
239
240 if (snd_BUG_ON(!f || !f->pool))
241 return -EINVAL;
242
243 /* allocate new pool */
244 newpool = snd_seq_pool_new(poolsize);
245 if (newpool == NULL)
246 return -ENOMEM;
247 if (snd_seq_pool_init(newpool) < 0) {
248 snd_seq_pool_delete(&newpool);
249 return -ENOMEM;
250 }
251
252 spin_lock_irqsave(&f->lock, flags);
253 /* remember old pool */
254 oldpool = f->pool;
255 oldhead = f->head;
256 /* exchange pools */
257 f->pool = newpool;
258 f->head = NULL;
259 f->tail = NULL;
260 f->cells = 0;
261 /* NOTE: overflow flag is not cleared */
262 spin_unlock_irqrestore(&f->lock, flags);
263
264 /* release cells in old pool */
265 for (cell = oldhead; cell; cell = next) {
266 next = cell->next;
267 snd_seq_cell_free(cell);
268 }
269 snd_seq_pool_delete(&oldpool);
270
271 return 0;
272}
1/*
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
22#include <sound/core.h>
23#include <linux/slab.h>
24#include "seq_fifo.h"
25#include "seq_lock.h"
26
27
28/* FIFO */
29
30/* create new fifo */
31struct snd_seq_fifo *snd_seq_fifo_new(int poolsize)
32{
33 struct snd_seq_fifo *f;
34
35 f = kzalloc(sizeof(*f), GFP_KERNEL);
36 if (!f)
37 return NULL;
38
39 f->pool = snd_seq_pool_new(poolsize);
40 if (f->pool == NULL) {
41 kfree(f);
42 return NULL;
43 }
44 if (snd_seq_pool_init(f->pool) < 0) {
45 snd_seq_pool_delete(&f->pool);
46 kfree(f);
47 return NULL;
48 }
49
50 spin_lock_init(&f->lock);
51 snd_use_lock_init(&f->use_lock);
52 init_waitqueue_head(&f->input_sleep);
53 atomic_set(&f->overflow, 0);
54
55 f->head = NULL;
56 f->tail = NULL;
57 f->cells = 0;
58
59 return f;
60}
61
62void snd_seq_fifo_delete(struct snd_seq_fifo **fifo)
63{
64 struct snd_seq_fifo *f;
65
66 if (snd_BUG_ON(!fifo))
67 return;
68 f = *fifo;
69 if (snd_BUG_ON(!f))
70 return;
71 *fifo = NULL;
72
73 snd_seq_fifo_clear(f);
74
75 /* wake up clients if any */
76 if (waitqueue_active(&f->input_sleep))
77 wake_up(&f->input_sleep);
78
79 /* release resources...*/
80 /*....................*/
81
82 if (f->pool) {
83 snd_seq_pool_done(f->pool);
84 snd_seq_pool_delete(&f->pool);
85 }
86
87 kfree(f);
88}
89
90static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f);
91
92/* clear queue */
93void snd_seq_fifo_clear(struct snd_seq_fifo *f)
94{
95 struct snd_seq_event_cell *cell;
96 unsigned long flags;
97
98 /* clear overflow flag */
99 atomic_set(&f->overflow, 0);
100
101 snd_use_lock_sync(&f->use_lock);
102 spin_lock_irqsave(&f->lock, flags);
103 /* drain the fifo */
104 while ((cell = fifo_cell_out(f)) != NULL) {
105 snd_seq_cell_free(cell);
106 }
107 spin_unlock_irqrestore(&f->lock, flags);
108}
109
110
111/* enqueue event to fifo */
112int snd_seq_fifo_event_in(struct snd_seq_fifo *f,
113 struct snd_seq_event *event)
114{
115 struct snd_seq_event_cell *cell;
116 unsigned long flags;
117 int err;
118
119 if (snd_BUG_ON(!f))
120 return -EINVAL;
121
122 snd_use_lock_use(&f->use_lock);
123 err = snd_seq_event_dup(f->pool, event, &cell, 1, NULL); /* always non-blocking */
124 if (err < 0) {
125 if ((err == -ENOMEM) || (err == -EAGAIN))
126 atomic_inc(&f->overflow);
127 snd_use_lock_free(&f->use_lock);
128 return err;
129 }
130
131 /* append new cells to fifo */
132 spin_lock_irqsave(&f->lock, flags);
133 if (f->tail != NULL)
134 f->tail->next = cell;
135 f->tail = cell;
136 if (f->head == NULL)
137 f->head = cell;
138 f->cells++;
139 spin_unlock_irqrestore(&f->lock, flags);
140
141 /* wakeup client */
142 if (waitqueue_active(&f->input_sleep))
143 wake_up(&f->input_sleep);
144
145 snd_use_lock_free(&f->use_lock);
146
147 return 0; /* success */
148
149}
150
151/* dequeue cell from fifo */
152static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f)
153{
154 struct snd_seq_event_cell *cell;
155
156 if ((cell = f->head) != NULL) {
157 f->head = cell->next;
158
159 /* reset tail if this was the last element */
160 if (f->tail == cell)
161 f->tail = NULL;
162
163 cell->next = NULL;
164 f->cells--;
165 }
166
167 return cell;
168}
169
170/* dequeue cell from fifo and copy on user space */
171int snd_seq_fifo_cell_out(struct snd_seq_fifo *f,
172 struct snd_seq_event_cell **cellp, int nonblock)
173{
174 struct snd_seq_event_cell *cell;
175 unsigned long flags;
176 wait_queue_t wait;
177
178 if (snd_BUG_ON(!f))
179 return -EINVAL;
180
181 *cellp = NULL;
182 init_waitqueue_entry(&wait, current);
183 spin_lock_irqsave(&f->lock, flags);
184 while ((cell = fifo_cell_out(f)) == NULL) {
185 if (nonblock) {
186 /* non-blocking - return immediately */
187 spin_unlock_irqrestore(&f->lock, flags);
188 return -EAGAIN;
189 }
190 set_current_state(TASK_INTERRUPTIBLE);
191 add_wait_queue(&f->input_sleep, &wait);
192 spin_unlock_irq(&f->lock);
193 schedule();
194 spin_lock_irq(&f->lock);
195 remove_wait_queue(&f->input_sleep, &wait);
196 if (signal_pending(current)) {
197 spin_unlock_irqrestore(&f->lock, flags);
198 return -ERESTARTSYS;
199 }
200 }
201 spin_unlock_irqrestore(&f->lock, flags);
202 *cellp = cell;
203
204 return 0;
205}
206
207
208void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f,
209 struct snd_seq_event_cell *cell)
210{
211 unsigned long flags;
212
213 if (cell) {
214 spin_lock_irqsave(&f->lock, flags);
215 cell->next = f->head;
216 f->head = cell;
217 f->cells++;
218 spin_unlock_irqrestore(&f->lock, flags);
219 }
220}
221
222
223/* polling; return non-zero if queue is available */
224int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file,
225 poll_table *wait)
226{
227 poll_wait(file, &f->input_sleep, wait);
228 return (f->cells > 0);
229}
230
231/* change the size of pool; all old events are removed */
232int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize)
233{
234 unsigned long flags;
235 struct snd_seq_pool *newpool, *oldpool;
236 struct snd_seq_event_cell *cell, *next, *oldhead;
237
238 if (snd_BUG_ON(!f || !f->pool))
239 return -EINVAL;
240
241 /* allocate new pool */
242 newpool = snd_seq_pool_new(poolsize);
243 if (newpool == NULL)
244 return -ENOMEM;
245 if (snd_seq_pool_init(newpool) < 0) {
246 snd_seq_pool_delete(&newpool);
247 return -ENOMEM;
248 }
249
250 spin_lock_irqsave(&f->lock, flags);
251 /* remember old pool */
252 oldpool = f->pool;
253 oldhead = f->head;
254 /* exchange pools */
255 f->pool = newpool;
256 f->head = NULL;
257 f->tail = NULL;
258 f->cells = 0;
259 /* NOTE: overflow flag is not cleared */
260 spin_unlock_irqrestore(&f->lock, flags);
261
262 /* release cells in old pool */
263 for (cell = oldhead; cell; cell = next) {
264 next = cell->next;
265 snd_seq_cell_free(cell);
266 }
267 snd_seq_pool_delete(&oldpool);
268
269 return 0;
270}