sound/core/seq/seq_memory.c

   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 <sound/driver.h>
  24 #include <linux/init.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 __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         } if (! (event->data.ext.len & SNDRV_SEQ_EXT_CHAINED)) {
 105                 return func(private_data, event->data.ext.ptr, len);
 106         }
 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 __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         snd_assert(cell != NULL, return);
 192         pool = cell->pool;
 193         snd_assert(pool != NULL, return);
 194
 195         spin_lock_irqsave(&pool->lock, flags);
 196         free_cell(pool, cell);
 197         if (snd_seq_ev_is_variable(&cell->event)) {
 198                 if (cell->event.data.ext.len & SNDRV_SEQ_EXT_CHAINED) {
 199                         struct snd_seq_event_cell *curp, *nextptr;
 200                         curp = cell->event.data.ext.ptr;
 201                         for (; curp; curp = nextptr) {
 202                                 nextptr = curp->next;
 203                                 curp->next = pool->free;
 204                                 free_cell(pool, curp);
 205                         }
 206                 }
 207         }
 208         if (waitqueue_active(&pool->output_sleep)) {
 209                 /* has enough space now? */
 210                 if (snd_seq_output_ok(pool))
 211                         wake_up(&pool->output_sleep);
 212         }
 213         spin_unlock_irqrestore(&pool->lock, flags);
 214 }
 215
 216
 217 /*
 218  * allocate an event cell.
 219  */
 220 static int snd_seq_cell_alloc(struct snd_seq_pool *pool,
 221                               struct snd_seq_event_cell **cellp,
 222                               int nonblock, struct file *file)
 223 {
 224         struct snd_seq_event_cell *cell;
 225         unsigned long flags;
 226         int err = -EAGAIN;
 227         wait_queue_t wait;
 228
 229         if (pool == NULL)
 230                 return -EINVAL;
 231
 232         *cellp = NULL;
 233
 234         init_waitqueue_entry(&wait, current);
 235         spin_lock_irqsave(&pool->lock, flags);
 236         if (pool->ptr == NULL) {        /* not initialized */
 237                 snd_printd("seq: pool is not initialized\n");
 238                 err = -EINVAL;
 239                 goto __error;
 240         }
 241         while (pool->free == NULL && ! nonblock && ! pool->closing) {
 242
 243                 set_current_state(TASK_INTERRUPTIBLE);
 244                 add_wait_queue(&pool->output_sleep, &wait);
 245                 spin_unlock_irq(&pool->lock);
 246                 schedule();
 247                 spin_lock_irq(&pool->lock);
 248                 remove_wait_queue(&pool->output_sleep, &wait);
 249                 /* interrupted? */
 250                 if (signal_pending(current)) {
 251                         err = -ERESTARTSYS;
 252                         goto __error;
 253                 }
 254         }
 255         if (pool->closing) { /* closing.. */
 256                 err = -ENOMEM;
 257                 goto __error;
 258         }
 259
 260         cell = pool->free;
 261         if (cell) {
 262                 int used;
 263                 pool->free = cell->next;
 264                 atomic_inc(&pool->counter);
 265                 used = atomic_read(&pool->counter);
 266                 if (pool->max_used < used)
 267                         pool->max_used = used;
 268                 pool->event_alloc_success++;
 269                 /* clear cell pointers */
 270                 cell->next = NULL;
 271                 err = 0;
 272         } else
 273                 pool->event_alloc_failures++;
 274         *cellp = cell;
 275
 276 __error:
 277         spin_unlock_irqrestore(&pool->lock, flags);
 278         return err;
 279 }
 280
 281
 282 /*
 283  * duplicate the event to a cell.
 284  * if the event has external data, the data is decomposed to additional
 285  * cells.
 286  */
 287 int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
 288                       struct snd_seq_event_cell **cellp, int nonblock,
 289                       struct file *file)
 290 {
 291         int ncells, err;
 292         unsigned int extlen;
 293         struct snd_seq_event_cell *cell;
 294
 295         *cellp = NULL;
 296
 297         ncells = 0;
 298         extlen = 0;
 299         if (snd_seq_ev_is_variable(event)) {
 300                 extlen = event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
 301                 ncells = (extlen + sizeof(struct snd_seq_event) - 1) / sizeof(struct snd_seq_event);
 302         }
 303         if (ncells >= pool->total_elements)
 304                 return -ENOMEM;
 305
 306         err = snd_seq_cell_alloc(pool, &cell, nonblock, file);
 307         if (err < 0)
 308                 return err;
 309
 310         /* copy the event */
 311         cell->event = *event;
 312
 313         /* decompose */
 314         if (snd_seq_ev_is_variable(event)) {
 315                 int len = extlen;
 316                 int is_chained = event->data.ext.len & SNDRV_SEQ_EXT_CHAINED;
 317                 int is_usrptr = event->data.ext.len & SNDRV_SEQ_EXT_USRPTR;
 318                 struct snd_seq_event_cell *src, *tmp, *tail;
 319                 char *buf;
 320
 321                 cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED;
 322                 cell->event.data.ext.ptr = NULL;
 323
 324                 src = (struct snd_seq_event_cell *)event->data.ext.ptr;
 325                 buf = (char *)event->data.ext.ptr;
 326                 tail = NULL;
 327
 328                 while (ncells-- > 0) {
 329                         int size = sizeof(struct snd_seq_event);
 330                         if (len < size)
 331                                 size = len;
 332                         err = snd_seq_cell_alloc(pool, &tmp, nonblock, file);
 333                         if (err < 0)
 334                                 goto __error;
 335                         if (cell->event.data.ext.ptr == NULL)
 336                                 cell->event.data.ext.ptr = tmp;
 337                         if (tail)
 338                                 tail->next = tmp;
 339                         tail = tmp;
 340                         /* copy chunk */
 341                         if (is_chained && src) {
 342                                 tmp->event = src->event;
 343                                 src = src->next;
 344                         } else if (is_usrptr) {
 345                                 if (copy_from_user(&tmp->event, (char __user *)buf, size)) {
 346                                         err = -EFAULT;
 347                                         goto __error;
 348                                 }
 349                         } else {
 350                                 memcpy(&tmp->event, buf, size);
 351                         }
 352                         buf += size;
 353                         len -= size;
 354                 }
 355         }
 356
 357         *cellp = cell;
 358         return 0;
 359
 360 __error:
 361         snd_seq_cell_free(cell);
 362         return err;
 363 }
 364
 365
 366 /* poll wait */
 367 int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
 368                            poll_table *wait)
 369 {
 370         poll_wait(file, &pool->output_sleep, wait);
 371         return snd_seq_output_ok(pool);
 372 }
 373
 374
 375 /* allocate room specified number of events */
 376 int snd_seq_pool_init(struct snd_seq_pool *pool)
 377 {
 378         int cell;
 379         struct snd_seq_event_cell *cellptr;
 380         unsigned long flags;
 381
 382         snd_assert(pool != NULL, return -EINVAL);
 383         if (pool->ptr)                  /* should be atomic? */
 384                 return 0;
 385
 386         pool->ptr = vmalloc(sizeof(struct snd_seq_event_cell) * pool->size);
 387         if (pool->ptr == NULL) {
 388                 snd_printd("seq: malloc for sequencer events failed\n");
 389                 return -ENOMEM;
 390         }
 391
 392         /* add new cells to the free cell list */
 393         spin_lock_irqsave(&pool->lock, flags);
 394         pool->free = NULL;
 395
 396         for (cell = 0; cell < pool->size; cell++) {
 397                 cellptr = pool->ptr + cell;
 398                 cellptr->pool = pool;
 399                 cellptr->next = pool->free;
 400                 pool->free = cellptr;
 401         }
 402         pool->room = (pool->size + 1) / 2;
 403
 404         /* init statistics */
 405         pool->max_used = 0;
 406         pool->total_elements = pool->size;
 407         spin_unlock_irqrestore(&pool->lock, flags);
 408         return 0;
 409 }
 410
 411 /* remove events */
 412 int snd_seq_pool_done(struct snd_seq_pool *pool)
 413 {
 414         unsigned long flags;
 415         struct snd_seq_event_cell *ptr;
 416         int max_count = 5 * HZ;
 417
 418         snd_assert(pool != NULL, return -EINVAL);
 419
 420         /* wait for closing all threads */
 421         spin_lock_irqsave(&pool->lock, flags);
 422         pool->closing = 1;
 423         spin_unlock_irqrestore(&pool->lock, flags);
 424
 425         if (waitqueue_active(&pool->output_sleep))
 426                 wake_up(&pool->output_sleep);
 427
 428         while (atomic_read(&pool->counter) > 0) {
 429                 if (max_count == 0) {
 430                         snd_printk(KERN_WARNING "snd_seq_pool_done timeout: %d cells remain\n", atomic_read(&pool->counter));
 431                         break;
 432                 }
 433                 schedule_timeout_uninterruptible(1);
 434                 max_count--;
 435         }
 436
 437         /* release all resources */
 438         spin_lock_irqsave(&pool->lock, flags);
 439         ptr = pool->ptr;
 440         pool->ptr = NULL;
 441         pool->free = NULL;
 442         pool->total_elements = 0;
 443         spin_unlock_irqrestore(&pool->lock, flags);
 444
 445         vfree(ptr);
 446
 447         spin_lock_irqsave(&pool->lock, flags);
 448         pool->closing = 0;
 449         spin_unlock_irqrestore(&pool->lock, flags);
 450
 451         return 0;
 452 }
 453
 454
 455 /* init new memory pool */
 456 struct snd_seq_pool *snd_seq_pool_new(int poolsize)
 457 {
 458         struct snd_seq_pool *pool;
 459
 460         /* create pool block */
 461         pool = kzalloc(sizeof(*pool), GFP_KERNEL);
 462         if (pool == NULL) {
 463                 snd_printd("seq: malloc failed for pool\n");
 464                 return NULL;
 465         }
 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 }