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/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 }