Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | ||
1da177e4 LT |
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 */ | |
c7e0b5bf | 31 | struct snd_seq_fifo *snd_seq_fifo_new(int poolsize) |
1da177e4 | 32 | { |
c7e0b5bf | 33 | struct snd_seq_fifo *f; |
1da177e4 | 34 | |
ecca82b4 | 35 | f = kzalloc(sizeof(*f), GFP_KERNEL); |
1da177e4 LT |
36 | if (f == NULL) { |
37 | snd_printd("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 | ||
c7e0b5bf | 64 | void snd_seq_fifo_delete(struct snd_seq_fifo **fifo) |
1da177e4 | 65 | { |
c7e0b5bf | 66 | struct snd_seq_fifo *f; |
1da177e4 | 67 | |
7eaa943c TI |
68 | if (snd_BUG_ON(!fifo)) |
69 | return; | |
1da177e4 | 70 | f = *fifo; |
7eaa943c TI |
71 | if (snd_BUG_ON(!f)) |
72 | return; | |
1da177e4 LT |
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 | ||
c7e0b5bf | 92 | static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f); |
1da177e4 LT |
93 | |
94 | /* clear queue */ | |
c7e0b5bf | 95 | void snd_seq_fifo_clear(struct snd_seq_fifo *f) |
1da177e4 | 96 | { |
c7e0b5bf | 97 | struct snd_seq_event_cell *cell; |
1da177e4 LT |
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 */ | |
c7e0b5bf TI |
114 | int snd_seq_fifo_event_in(struct snd_seq_fifo *f, |
115 | struct snd_seq_event *event) | |
1da177e4 | 116 | { |
c7e0b5bf | 117 | struct snd_seq_event_cell *cell; |
1da177e4 LT |
118 | unsigned long flags; |
119 | int err; | |
120 | ||
7eaa943c TI |
121 | if (snd_BUG_ON(!f)) |
122 | return -EINVAL; | |
1da177e4 LT |
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 */ | |
c7e0b5bf | 154 | static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f) |
1da177e4 | 155 | { |
c7e0b5bf | 156 | struct snd_seq_event_cell *cell; |
1da177e4 LT |
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 */ | |
c7e0b5bf TI |
173 | int snd_seq_fifo_cell_out(struct snd_seq_fifo *f, |
174 | struct snd_seq_event_cell **cellp, int nonblock) | |
1da177e4 | 175 | { |
c7e0b5bf | 176 | struct snd_seq_event_cell *cell; |
1da177e4 LT |
177 | unsigned long flags; |
178 | wait_queue_t wait; | |
179 | ||
7eaa943c TI |
180 | if (snd_BUG_ON(!f)) |
181 | return -EINVAL; | |
1da177e4 LT |
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 | ||
c7e0b5bf TI |
210 | void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f, |
211 | struct snd_seq_event_cell *cell) | |
1da177e4 LT |
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 */ | |
c7e0b5bf TI |
226 | int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file, |
227 | poll_table *wait) | |
1da177e4 LT |
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 */ | |
c7e0b5bf | 234 | int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize) |
1da177e4 LT |
235 | { |
236 | unsigned long flags; | |
c7e0b5bf TI |
237 | struct snd_seq_pool *newpool, *oldpool; |
238 | struct snd_seq_event_cell *cell, *next, *oldhead; | |
1da177e4 | 239 | |
7eaa943c TI |
240 | if (snd_BUG_ON(!f || !f->pool)) |
241 | return -EINVAL; | |
1da177e4 LT |
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 | } |