1 /* 2 * ALSA sequencer Memory Manager 3 * Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl> 4 * Jaroslav Kysela <perex@perex.cz> 5 * 2000 by Takashi Iwai <tiwai@suse.de> 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 <linux/init.h> 24 #include <linux/export.h> 25 #include <linux/slab.h> 26 #include <linux/vmalloc.h> 27 #include <sound/core.h> 28 29 #include <sound/seq_kernel.h> 30 #include "seq_memory.h" 31 #include "seq_queue.h" 32 #include "seq_info.h" 33 #include "seq_lock.h" 34 35 static inline int snd_seq_pool_available(struct snd_seq_pool *pool) 36 { 37 return pool->total_elements - atomic_read(&pool->counter); 38 } 39 40 static inline int snd_seq_output_ok(struct snd_seq_pool *pool) 41 { 42 return snd_seq_pool_available(pool) >= pool->room; 43 } 44 45 /* 46 * Variable length event: 47 * The event like sysex uses variable length type. 48 * The external data may be stored in three different formats. 49 * 1) kernel space 50 * This is the normal case. 51 * ext.data.len = length 52 * ext.data.ptr = buffer pointer 53 * 2) user space 54 * When an event is generated via read(), the external data is 55 * kept in user space until expanded. 56 * ext.data.len = length | SNDRV_SEQ_EXT_USRPTR 57 * ext.data.ptr = userspace pointer 58 * 3) chained cells 59 * When the variable length event is enqueued (in prioq or fifo), 60 * the external data is decomposed to several cells. 61 * ext.data.len = length | SNDRV_SEQ_EXT_CHAINED 62 * ext.data.ptr = the additiona cell head 63 * -> cell.next -> cell.next -> .. 64 */ 65 66 /* 67 * exported: 68 * call dump function to expand external data. 69 */ 70 71 static int get_var_len(const struct snd_seq_event *event) 72 { 73 if ((event->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE) 74 return -EINVAL; 75 76 return event->data.ext.len & ~SNDRV_SEQ_EXT_MASK; 77 } 78 79 int snd_seq_dump_var_event(const struct snd_seq_event *event, 80 snd_seq_dump_func_t func, void *private_data) 81 { 82 int len, err; 83 struct snd_seq_event_cell *cell; 84 85 if ((len = get_var_len(event)) <= 0) 86 return len; 87 88 if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) { 89 char buf[32]; 90 char __user *curptr = (char __force __user *)event->data.ext.ptr; 91 while (len > 0) { 92 int size = sizeof(buf); 93 if (len < size) 94 size = len; 95 if (copy_from_user(buf, curptr, size)) 96 return -EFAULT; 97 err = func(private_data, buf, size); 98 if (err < 0) 99 return err; 100 curptr += size; 101 len -= size; 102 } 103 return 0; 104 } 105 if (!(event->data.ext.len & SNDRV_SEQ_EXT_CHAINED)) 106 return func(private_data, event->data.ext.ptr, len); 107 108 cell = (struct snd_seq_event_cell *)event->data.ext.ptr; 109 for (; len > 0 && cell; cell = cell->next) { 110 int size = sizeof(struct snd_seq_event); 111 if (len < size) 112 size = len; 113 err = func(private_data, &cell->event, size); 114 if (err < 0) 115 return err; 116 len -= size; 117 } 118 return 0; 119 } 120 121 EXPORT_SYMBOL(snd_seq_dump_var_event); 122 123 124 /* 125 * exported: 126 * expand the variable length event to linear buffer space. 127 */ 128 129 static int seq_copy_in_kernel(char **bufptr, const void *src, int size) 130 { 131 memcpy(*bufptr, src, size); 132 *bufptr += size; 133 return 0; 134 } 135 136 static int seq_copy_in_user(char __user **bufptr, const void *src, int size) 137 { 138 if (copy_to_user(*bufptr, src, size)) 139 return -EFAULT; 140 *bufptr += size; 141 return 0; 142 } 143 144 int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf, 145 int in_kernel, int size_aligned) 146 { 147 int len, newlen; 148 int err; 149 150 if ((len = get_var_len(event)) < 0) 151 return len; 152 newlen = len; 153 if (size_aligned > 0) 154 newlen = roundup(len, size_aligned); 155 if (count < newlen) 156 return -EAGAIN; 157 158 if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) { 159 if (! in_kernel) 160 return -EINVAL; 161 if (copy_from_user(buf, (void __force __user *)event->data.ext.ptr, len)) 162 return -EFAULT; 163 return newlen; 164 } 165 err = snd_seq_dump_var_event(event, 166 in_kernel ? (snd_seq_dump_func_t)seq_copy_in_kernel : 167 (snd_seq_dump_func_t)seq_copy_in_user, 168 &buf); 169 return err < 0 ? err : newlen; 170 } 171 172 EXPORT_SYMBOL(snd_seq_expand_var_event); 173 174 /* 175 * release this cell, free extended data if available 176 */ 177 178 static inline void free_cell(struct snd_seq_pool *pool, 179 struct snd_seq_event_cell *cell) 180 { 181 cell->next = pool->free; 182 pool->free = cell; 183 atomic_dec(&pool->counter); 184 } 185 186 void snd_seq_cell_free(struct snd_seq_event_cell * cell) 187 { 188 unsigned long flags; 189 struct snd_seq_pool *pool; 190 191 if (snd_BUG_ON(!cell)) 192 return; 193 pool = cell->pool; 194 if (snd_BUG_ON(!pool)) 195 return; 196 197 spin_lock_irqsave(&pool->lock, flags); 198 free_cell(pool, cell); 199 if (snd_seq_ev_is_variable(&cell->event)) { 200 if (cell->event.data.ext.len & SNDRV_SEQ_EXT_CHAINED) { 201 struct snd_seq_event_cell *curp, *nextptr; 202 curp = cell->event.data.ext.ptr; 203 for (; curp; curp = nextptr) { 204 nextptr = curp->next; 205 curp->next = pool->free; 206 free_cell(pool, curp); 207 } 208 } 209 } 210 if (waitqueue_active(&pool->output_sleep)) { 211 /* has enough space now? */ 212 if (snd_seq_output_ok(pool)) 213 wake_up(&pool->output_sleep); 214 } 215 spin_unlock_irqrestore(&pool->lock, flags); 216 } 217 218 219 /* 220 * allocate an event cell. 221 */ 222 static int snd_seq_cell_alloc(struct snd_seq_pool *pool, 223 struct snd_seq_event_cell **cellp, 224 int nonblock, struct file *file) 225 { 226 struct snd_seq_event_cell *cell; 227 unsigned long flags; 228 int err = -EAGAIN; 229 wait_queue_t wait; 230 231 if (pool == NULL) 232 return -EINVAL; 233 234 *cellp = NULL; 235 236 init_waitqueue_entry(&wait, current); 237 spin_lock_irqsave(&pool->lock, flags); 238 if (pool->ptr == NULL) { /* not initialized */ 239 pr_debug("ALSA: seq: pool is not initialized\n"); 240 err = -EINVAL; 241 goto __error; 242 } 243 while (pool->free == NULL && ! nonblock && ! pool->closing) { 244 245 set_current_state(TASK_INTERRUPTIBLE); 246 add_wait_queue(&pool->output_sleep, &wait); 247 spin_unlock_irq(&pool->lock); 248 schedule(); 249 spin_lock_irq(&pool->lock); 250 remove_wait_queue(&pool->output_sleep, &wait); 251 /* interrupted? */ 252 if (signal_pending(current)) { 253 err = -ERESTARTSYS; 254 goto __error; 255 } 256 } 257 if (pool->closing) { /* closing.. */ 258 err = -ENOMEM; 259 goto __error; 260 } 261 262 cell = pool->free; 263 if (cell) { 264 int used; 265 pool->free = cell->next; 266 atomic_inc(&pool->counter); 267 used = atomic_read(&pool->counter); 268 if (pool->max_used < used) 269 pool->max_used = used; 270 pool->event_alloc_success++; 271 /* clear cell pointers */ 272 cell->next = NULL; 273 err = 0; 274 } else 275 pool->event_alloc_failures++; 276 *cellp = cell; 277 278 __error: 279 spin_unlock_irqrestore(&pool->lock, flags); 280 return err; 281 } 282 283 284 /* 285 * duplicate the event to a cell. 286 * if the event has external data, the data is decomposed to additional 287 * cells. 288 */ 289 int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event, 290 struct snd_seq_event_cell **cellp, int nonblock, 291 struct file *file) 292 { 293 int ncells, err; 294 unsigned int extlen; 295 struct snd_seq_event_cell *cell; 296 297 *cellp = NULL; 298 299 ncells = 0; 300 extlen = 0; 301 if (snd_seq_ev_is_variable(event)) { 302 extlen = event->data.ext.len & ~SNDRV_SEQ_EXT_MASK; 303 ncells = (extlen + sizeof(struct snd_seq_event) - 1) / sizeof(struct snd_seq_event); 304 } 305 if (ncells >= pool->total_elements) 306 return -ENOMEM; 307 308 err = snd_seq_cell_alloc(pool, &cell, nonblock, file); 309 if (err < 0) 310 return err; 311 312 /* copy the event */ 313 cell->event = *event; 314 315 /* decompose */ 316 if (snd_seq_ev_is_variable(event)) { 317 int len = extlen; 318 int is_chained = event->data.ext.len & SNDRV_SEQ_EXT_CHAINED; 319 int is_usrptr = event->data.ext.len & SNDRV_SEQ_EXT_USRPTR; 320 struct snd_seq_event_cell *src, *tmp, *tail; 321 char *buf; 322 323 cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED; 324 cell->event.data.ext.ptr = NULL; 325 326 src = (struct snd_seq_event_cell *)event->data.ext.ptr; 327 buf = (char *)event->data.ext.ptr; 328 tail = NULL; 329 330 while (ncells-- > 0) { 331 int size = sizeof(struct snd_seq_event); 332 if (len < size) 333 size = len; 334 err = snd_seq_cell_alloc(pool, &tmp, nonblock, file); 335 if (err < 0) 336 goto __error; 337 if (cell->event.data.ext.ptr == NULL) 338 cell->event.data.ext.ptr = tmp; 339 if (tail) 340 tail->next = tmp; 341 tail = tmp; 342 /* copy chunk */ 343 if (is_chained && src) { 344 tmp->event = src->event; 345 src = src->next; 346 } else if (is_usrptr) { 347 if (copy_from_user(&tmp->event, (char __force __user *)buf, size)) { 348 err = -EFAULT; 349 goto __error; 350 } 351 } else { 352 memcpy(&tmp->event, buf, size); 353 } 354 buf += size; 355 len -= size; 356 } 357 } 358 359 *cellp = cell; 360 return 0; 361 362 __error: 363 snd_seq_cell_free(cell); 364 return err; 365 } 366 367 368 /* poll wait */ 369 int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file, 370 poll_table *wait) 371 { 372 poll_wait(file, &pool->output_sleep, wait); 373 return snd_seq_output_ok(pool); 374 } 375 376 377 /* allocate room specified number of events */ 378 int snd_seq_pool_init(struct snd_seq_pool *pool) 379 { 380 int cell; 381 struct snd_seq_event_cell *cellptr; 382 unsigned long flags; 383 384 if (snd_BUG_ON(!pool)) 385 return -EINVAL; 386 if (pool->ptr) /* should be atomic? */ 387 return 0; 388 389 pool->ptr = vmalloc(sizeof(struct snd_seq_event_cell) * pool->size); 390 if (!pool->ptr) 391 return -ENOMEM; 392 393 /* add new cells to the free cell list */ 394 spin_lock_irqsave(&pool->lock, flags); 395 pool->free = NULL; 396 397 for (cell = 0; cell < pool->size; cell++) { 398 cellptr = pool->ptr + cell; 399 cellptr->pool = pool; 400 cellptr->next = pool->free; 401 pool->free = cellptr; 402 } 403 pool->room = (pool->size + 1) / 2; 404 405 /* init statistics */ 406 pool->max_used = 0; 407 pool->total_elements = pool->size; 408 spin_unlock_irqrestore(&pool->lock, flags); 409 return 0; 410 } 411 412 /* remove events */ 413 int snd_seq_pool_done(struct snd_seq_pool *pool) 414 { 415 unsigned long flags; 416 struct snd_seq_event_cell *ptr; 417 int max_count = 5 * HZ; 418 419 if (snd_BUG_ON(!pool)) 420 return -EINVAL; 421 422 /* wait for closing all threads */ 423 spin_lock_irqsave(&pool->lock, flags); 424 pool->closing = 1; 425 spin_unlock_irqrestore(&pool->lock, flags); 426 427 if (waitqueue_active(&pool->output_sleep)) 428 wake_up(&pool->output_sleep); 429 430 while (atomic_read(&pool->counter) > 0) { 431 if (max_count == 0) { 432 pr_warn("ALSA: snd_seq_pool_done timeout: %d cells remain\n", atomic_read(&pool->counter)); 433 break; 434 } 435 schedule_timeout_uninterruptible(1); 436 max_count--; 437 } 438 439 /* release all resources */ 440 spin_lock_irqsave(&pool->lock, flags); 441 ptr = pool->ptr; 442 pool->ptr = NULL; 443 pool->free = NULL; 444 pool->total_elements = 0; 445 spin_unlock_irqrestore(&pool->lock, flags); 446 447 vfree(ptr); 448 449 spin_lock_irqsave(&pool->lock, flags); 450 pool->closing = 0; 451 spin_unlock_irqrestore(&pool->lock, flags); 452 453 return 0; 454 } 455 456 457 /* init new memory pool */ 458 struct snd_seq_pool *snd_seq_pool_new(int poolsize) 459 { 460 struct snd_seq_pool *pool; 461 462 /* create pool block */ 463 pool = kzalloc(sizeof(*pool), GFP_KERNEL); 464 if (!pool) 465 return NULL; 466 spin_lock_init(&pool->lock); 467 pool->ptr = NULL; 468 pool->free = NULL; 469 pool->total_elements = 0; 470 atomic_set(&pool->counter, 0); 471 pool->closing = 0; 472 init_waitqueue_head(&pool->output_sleep); 473 474 pool->size = poolsize; 475 476 /* init statistics */ 477 pool->max_used = 0; 478 return pool; 479 } 480 481 /* remove memory pool */ 482 int snd_seq_pool_delete(struct snd_seq_pool **ppool) 483 { 484 struct snd_seq_pool *pool = *ppool; 485 486 *ppool = NULL; 487 if (pool == NULL) 488 return 0; 489 snd_seq_pool_done(pool); 490 kfree(pool); 491 return 0; 492 } 493 494 /* initialize sequencer memory */ 495 int __init snd_sequencer_memory_init(void) 496 { 497 return 0; 498 } 499 500 /* release sequencer memory */ 501 void __exit snd_sequencer_memory_done(void) 502 { 503 } 504 505 506 /* exported to seq_clientmgr.c */ 507 void snd_seq_info_pool(struct snd_info_buffer *buffer, 508 struct snd_seq_pool *pool, char *space) 509 { 510 if (pool == NULL) 511 return; 512 snd_iprintf(buffer, "%sPool size : %d\n", space, pool->total_elements); 513 snd_iprintf(buffer, "%sCells in use : %d\n", space, atomic_read(&pool->counter)); 514 snd_iprintf(buffer, "%sPeak cells in use : %d\n", space, pool->max_used); 515 snd_iprintf(buffer, "%sAlloc success : %d\n", space, pool->event_alloc_success); 516 snd_iprintf(buffer, "%sAlloc failures : %d\n", space, pool->event_alloc_failures); 517 } 518