Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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/driver.h> |
| 23 | #include <sound/core.h> |
| 24 | #include <linux/slab.h> |
| 25 | #include "seq_fifo.h" |
| 26 | #include "seq_lock.h" |
| 27 | |
| 28 | |
| 29 | /* FIFO */ |
| 30 | |
| 31 | /* create new fifo */ |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 32 | struct snd_seq_fifo *snd_seq_fifo_new(int poolsize) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | { |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 34 | struct snd_seq_fifo *f; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | |
Takashi Iwai | ecca82b | 2005-09-09 14:20:49 +0200 | [diff] [blame] | 36 | f = kzalloc(sizeof(*f), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | if (f == NULL) { |
| 38 | snd_printd("malloc failed for snd_seq_fifo_new() \n"); |
| 39 | return NULL; |
| 40 | } |
| 41 | |
| 42 | f->pool = snd_seq_pool_new(poolsize); |
| 43 | if (f->pool == NULL) { |
| 44 | kfree(f); |
| 45 | return NULL; |
| 46 | } |
| 47 | if (snd_seq_pool_init(f->pool) < 0) { |
| 48 | snd_seq_pool_delete(&f->pool); |
| 49 | kfree(f); |
| 50 | return NULL; |
| 51 | } |
| 52 | |
| 53 | spin_lock_init(&f->lock); |
| 54 | snd_use_lock_init(&f->use_lock); |
| 55 | init_waitqueue_head(&f->input_sleep); |
| 56 | atomic_set(&f->overflow, 0); |
| 57 | |
| 58 | f->head = NULL; |
| 59 | f->tail = NULL; |
| 60 | f->cells = 0; |
| 61 | |
| 62 | return f; |
| 63 | } |
| 64 | |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 65 | void snd_seq_fifo_delete(struct snd_seq_fifo **fifo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | { |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 67 | struct snd_seq_fifo *f; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | |
| 69 | snd_assert(fifo != NULL, return); |
| 70 | f = *fifo; |
| 71 | snd_assert(f != NULL, return); |
| 72 | *fifo = NULL; |
| 73 | |
| 74 | snd_seq_fifo_clear(f); |
| 75 | |
| 76 | /* wake up clients if any */ |
| 77 | if (waitqueue_active(&f->input_sleep)) |
| 78 | wake_up(&f->input_sleep); |
| 79 | |
| 80 | /* release resources...*/ |
| 81 | /*....................*/ |
| 82 | |
| 83 | if (f->pool) { |
| 84 | snd_seq_pool_done(f->pool); |
| 85 | snd_seq_pool_delete(&f->pool); |
| 86 | } |
| 87 | |
| 88 | kfree(f); |
| 89 | } |
| 90 | |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 91 | static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | |
| 93 | /* clear queue */ |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 94 | void snd_seq_fifo_clear(struct snd_seq_fifo *f) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | { |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 96 | struct snd_seq_event_cell *cell; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | unsigned long flags; |
| 98 | |
| 99 | /* clear overflow flag */ |
| 100 | atomic_set(&f->overflow, 0); |
| 101 | |
| 102 | snd_use_lock_sync(&f->use_lock); |
| 103 | spin_lock_irqsave(&f->lock, flags); |
| 104 | /* drain the fifo */ |
| 105 | while ((cell = fifo_cell_out(f)) != NULL) { |
| 106 | snd_seq_cell_free(cell); |
| 107 | } |
| 108 | spin_unlock_irqrestore(&f->lock, flags); |
| 109 | } |
| 110 | |
| 111 | |
| 112 | /* enqueue event to fifo */ |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 113 | int snd_seq_fifo_event_in(struct snd_seq_fifo *f, |
| 114 | struct snd_seq_event *event) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | { |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 116 | struct snd_seq_event_cell *cell; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | unsigned long flags; |
| 118 | int err; |
| 119 | |
| 120 | snd_assert(f != NULL, 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) |
| 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 */ |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 152 | static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | { |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 154 | struct snd_seq_event_cell *cell; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 */ |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 171 | int snd_seq_fifo_cell_out(struct snd_seq_fifo *f, |
| 172 | struct snd_seq_event_cell **cellp, int nonblock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | { |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 174 | struct snd_seq_event_cell *cell; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | unsigned long flags; |
| 176 | wait_queue_t wait; |
| 177 | |
| 178 | snd_assert(f != NULL, return -EINVAL); |
| 179 | |
| 180 | *cellp = NULL; |
| 181 | init_waitqueue_entry(&wait, current); |
| 182 | spin_lock_irqsave(&f->lock, flags); |
| 183 | while ((cell = fifo_cell_out(f)) == NULL) { |
| 184 | if (nonblock) { |
| 185 | /* non-blocking - return immediately */ |
| 186 | spin_unlock_irqrestore(&f->lock, flags); |
| 187 | return -EAGAIN; |
| 188 | } |
| 189 | set_current_state(TASK_INTERRUPTIBLE); |
| 190 | add_wait_queue(&f->input_sleep, &wait); |
| 191 | spin_unlock_irq(&f->lock); |
| 192 | schedule(); |
| 193 | spin_lock_irq(&f->lock); |
| 194 | remove_wait_queue(&f->input_sleep, &wait); |
| 195 | if (signal_pending(current)) { |
| 196 | spin_unlock_irqrestore(&f->lock, flags); |
| 197 | return -ERESTARTSYS; |
| 198 | } |
| 199 | } |
| 200 | spin_unlock_irqrestore(&f->lock, flags); |
| 201 | *cellp = cell; |
| 202 | |
| 203 | return 0; |
| 204 | } |
| 205 | |
| 206 | |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 207 | void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f, |
| 208 | struct snd_seq_event_cell *cell) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | { |
| 210 | unsigned long flags; |
| 211 | |
| 212 | if (cell) { |
| 213 | spin_lock_irqsave(&f->lock, flags); |
| 214 | cell->next = f->head; |
| 215 | f->head = cell; |
| 216 | f->cells++; |
| 217 | spin_unlock_irqrestore(&f->lock, flags); |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | |
| 222 | /* polling; return non-zero if queue is available */ |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 223 | int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file, |
| 224 | poll_table *wait) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | { |
| 226 | poll_wait(file, &f->input_sleep, wait); |
| 227 | return (f->cells > 0); |
| 228 | } |
| 229 | |
| 230 | /* change the size of pool; all old events are removed */ |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 231 | int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | { |
| 233 | unsigned long flags; |
Takashi Iwai | c7e0b5b | 2005-11-17 14:04:02 +0100 | [diff] [blame] | 234 | struct snd_seq_pool *newpool, *oldpool; |
| 235 | struct snd_seq_event_cell *cell, *next, *oldhead; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | |
| 237 | snd_assert(f != NULL && f->pool != NULL, return -EINVAL); |
| 238 | |
| 239 | /* allocate new pool */ |
| 240 | newpool = snd_seq_pool_new(poolsize); |
| 241 | if (newpool == NULL) |
| 242 | return -ENOMEM; |
| 243 | if (snd_seq_pool_init(newpool) < 0) { |
| 244 | snd_seq_pool_delete(&newpool); |
| 245 | return -ENOMEM; |
| 246 | } |
| 247 | |
| 248 | spin_lock_irqsave(&f->lock, flags); |
| 249 | /* remember old pool */ |
| 250 | oldpool = f->pool; |
| 251 | oldhead = f->head; |
| 252 | /* exchange pools */ |
| 253 | f->pool = newpool; |
| 254 | f->head = NULL; |
| 255 | f->tail = NULL; |
| 256 | f->cells = 0; |
| 257 | /* NOTE: overflow flag is not cleared */ |
| 258 | spin_unlock_irqrestore(&f->lock, flags); |
| 259 | |
| 260 | /* release cells in old pool */ |
| 261 | for (cell = oldhead; cell; cell = next) { |
| 262 | next = cell->next; |
| 263 | snd_seq_cell_free(cell); |
| 264 | } |
| 265 | snd_seq_pool_delete(&oldpool); |
| 266 | |
| 267 | return 0; |
| 268 | } |