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