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