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         if (snd_BUG_ON(!cell))
 191                 return;
 192         pool = cell->pool;
 193         if (snd_BUG_ON(!pool))
 194                 return;
 195
 196         spin_lock_irqsave(&pool->lock, flags);
 197         free_cell(pool, cell);
 198         if (snd_seq_ev_is_variable(&cell->event)) {
 199                 if (cell->event.data.ext.len & SNDRV_SEQ_EXT_CHAINED) {
 200                         struct snd_seq_event_cell *curp, *nextptr;
 201                         curp = cell->event.data.ext.ptr;
 202                         for (; curp; curp = nextptr) {
 203                                 nextptr = curp->next;
 204                                 curp->next = pool->free;
 205                                 free_cell(pool, curp);
 206                         }
 207                 }
 208         }
 209         if (waitqueue_active(&pool->output_sleep)) {
 210                 /* has enough space now? */
 211                 if (snd_seq_output_ok(pool))
 212                         wake_up(&pool->output_sleep);
 213         }
 214         spin_unlock_irqrestore(&pool->lock, flags);
 215 }
 216
 217
 218 /*
 219  * allocate an event cell.
 220  */
 221 static int snd_seq_cell_alloc(struct snd_seq_pool *pool,
 222                               struct snd_seq_event_cell **cellp,
 223                               int nonblock, struct file *file)
 224 {
 225         struct snd_seq_event_cell *cell;
 226         unsigned long flags;
 227         int err = -EAGAIN;
 228         wait_queue_t wait;
 229
 230         if (pool == NULL)
 231                 return -EINVAL;
 232
 233         *cellp = NULL;
 234
 235         init_waitqueue_entry(&wait, current);
 236         spin_lock_irqsave(&pool->lock, flags);
 237         if (pool->ptr == NULL) {        /* not initialized */
 238                 snd_printd("seq: pool is not initialized\n");
 239                 err = -EINVAL;
 240                 goto __error;
 241         }
 242         while (pool->free == NULL && ! nonblock && ! pool->closing) {
 243
 244                 set_current_state(TASK_INTERRUPTIBLE);
 245                 add_wait_queue(&pool->output_sleep, &wait);
 246                 spin_unlock_irq(&pool->lock);
 247                 schedule();
 248                 spin_lock_irq(&pool->lock);
 249                 remove_wait_queue(&pool->output_sleep, &wait);
 250                 /* interrupted? */
 251                 if (signal_pending(current)) {
 252                         err = -ERESTARTSYS;
 253                         goto __error;
 254                 }
 255         }
 256         if (pool->closing) { /* closing.. */
 257                 err = -ENOMEM;
 258                 goto __error;
 259         }
 260
 261         cell = pool->free;
 262         if (cell) {
 263                 int used;
 264                 pool->free = cell->next;
 265                 atomic_inc(&pool->counter);
 266                 used = atomic_read(&pool->counter);
 267                 if (pool->max_used < used)
 268                         pool->max_used = used;
 269                 pool->event_alloc_success++;
 270                 /* clear cell pointers */
 271                 cell->next = NULL;
 272                 err = 0;
 273         } else
 274                 pool->event_alloc_failures++;
 275         *cellp = cell;
 276
 277 __error:
 278         spin_unlock_irqrestore(&pool->lock, flags);
 279         return err;
 280 }
 281
 282
 283 /*
 284  * duplicate the event to a cell.
 285  * if the event has external data, the data is decomposed to additional
 286  * cells.
 287  */
 288 int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
 289                       struct snd_seq_event_cell **cellp, int nonblock,
 290                       struct file *file)
 291 {
 292         int ncells, err;
 293         unsigned int extlen;
 294         struct snd_seq_event_cell *cell;
 295
 296         *cellp = NULL;
 297
 298         ncells = 0;
 299         extlen = 0;
 300         if (snd_seq_ev_is_variable(event)) {
 301                 extlen = event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
 302                 ncells = (extlen + sizeof(struct snd_seq_event) - 1) / sizeof(struct snd_seq_event);
 303         }
 304         if (ncells >= pool->total_elements)
 305                 return -ENOMEM;
 306
 307         err = snd_seq_cell_alloc(pool, &cell, nonblock, file);
 308         if (err < 0)
 309                 return err;
 310
 311         /* copy the event */
 312         cell->event = *event;
 313
 314         /* decompose */
 315         if (snd_seq_ev_is_variable(event)) {
 316                 int len = extlen;
 317                 int is_chained = event->data.ext.len & SNDRV_SEQ_EXT_CHAINED;
 318                 int is_usrptr = event->data.ext.len & SNDRV_SEQ_EXT_USRPTR;
 319                 struct snd_seq_event_cell *src, *tmp, *tail;
 320                 char *buf;
 321
 322                 cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED;
 323                 cell->event.data.ext.ptr = NULL;
 324
 325                 src = (struct snd_seq_event_cell *)event->data.ext.ptr;
 326                 buf = (char *)event->data.ext.ptr;
 327                 tail = NULL;
 328
 329                 while (ncells-- > 0) {
 330                         int size = sizeof(struct snd_seq_event);
 331                         if (len < size)
 332                                 size = len;
 333                         err = snd_seq_cell_alloc(pool, &tmp, nonblock, file);
 334                         if (err < 0)
 335                                 goto __error;
 336                         if (cell->event.data.ext.ptr == NULL)
 337                                 cell->event.data.ext.ptr = tmp;
 338                         if (tail)
 339                                 tail->next = tmp;
 340                         tail = tmp;
 341                         /* copy chunk */
 342                         if (is_chained && src) {
 343                                 tmp->event = src->event;
 344                                 src = src->next;
 345                         } else if (is_usrptr) {
 346                                 if (copy_from_user(&tmp->event, (char __user *)buf, size)) {
 347                                         err = -EFAULT;
 348                                         goto __error;
 349                                 }
 350                         } else {
 351                                 memcpy(&tmp->event, buf, size);
 352                         }
 353                         buf += size;
 354                         len -= size;
 355                 }
 356         }
 357
 358         *cellp = cell;
 359         return 0;
 360
 361 __error:
 362         snd_seq_cell_free(cell);
 363         return err;
 364 }
 365
 366
 367 /* poll wait */
 368 int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
 369                            poll_table *wait)
 370 {
 371         poll_wait(file, &pool->output_sleep, wait);
 372         return snd_seq_output_ok(pool);
 373 }
 374
 375
 376 /* allocate room specified number of events */
 377 int snd_seq_pool_init(struct snd_seq_pool *pool)
 378 {
 379         int cell;
 380         struct snd_seq_event_cell *cellptr;
 381         unsigned long flags;
 382
 383         if (snd_BUG_ON(!pool))
 384                 return -EINVAL;
 385         if (pool->ptr)                  /* should be atomic? */
 386                 return 0;
 387
 388         pool->ptr = vmalloc(sizeof(struct snd_seq_event_cell) * pool->size);
 389         if (pool->ptr == NULL) {
 390                 snd_printd("seq: malloc for sequencer events failed\n");
 391                 return -ENOMEM;
 392         }
 393
 394         /* add new cells to the free cell list */
 395         spin_lock_irqsave(&pool->lock, flags);
 396         pool->free = NULL;
 397
 398         for (cell = 0; cell < pool->size; cell++) {
 399                 cellptr = pool->ptr + cell;
 400                 cellptr->pool = pool;
 401                 cellptr->next = pool->free;
 402                 pool->free = cellptr;
 403         }
 404         pool->room = (pool->size + 1) / 2;
 405
 406         /* init statistics */
 407         pool->max_used = 0;
 408         pool->total_elements = pool->size;
 409         spin_unlock_irqrestore(&pool->lock, flags);
 410         return 0;
 411 }
 412
 413 /* remove events */
 414 int snd_seq_pool_done(struct snd_seq_pool *pool)
 415 {
 416         unsigned long flags;
 417         struct snd_seq_event_cell *ptr;
 418         int max_count = 5 * HZ;
 419
 420         if (snd_BUG_ON(!pool))
 421                 return -EINVAL;
 422
 423         /* wait for closing all threads */
 424         spin_lock_irqsave(&pool->lock, flags);
 425         pool->closing = 1;
 426         spin_unlock_irqrestore(&pool->lock, flags);
 427
 428         if (waitqueue_active(&pool->output_sleep))
 429                 wake_up(&pool->output_sleep);
 430
 431         while (atomic_read(&pool->counter) > 0) {
 432                 if (max_count == 0) {
 433                         snd_printk(KERN_WARNING "snd_seq_pool_done timeout: %d cells remain\n", atomic_read(&pool->counter));
 434                         break;
 435                 }
 436                 schedule_timeout_uninterruptible(1);
 437                 max_count--;
 438         }
 439
 440         /* release all resources */
 441         spin_lock_irqsave(&pool->lock, flags);
 442         ptr = pool->ptr;
 443         pool->ptr = NULL;
 444         pool->free = NULL;
 445         pool->total_elements = 0;
 446         spin_unlock_irqrestore(&pool->lock, flags);
 447
 448         vfree(ptr);
 449
 450         spin_lock_irqsave(&pool->lock, flags);
 451         pool->closing = 0;
 452         spin_unlock_irqrestore(&pool->lock, flags);
 453
 454         return 0;
 455 }
 456
 457
 458 /* init new memory pool */
 459 struct snd_seq_pool *snd_seq_pool_new(int poolsize)
 460 {
 461         struct snd_seq_pool *pool;
 462
 463         /* create pool block */
 464         pool = kzalloc(sizeof(*pool), GFP_KERNEL);
 465         if (pool == NULL) {
 466                 snd_printd("seq: malloc failed for pool\n");
 467                 return NULL;
 468         }
 469         spin_lock_init(&pool->lock);
 470         pool->ptr = NULL;
 471         pool->free = NULL;
 472         pool->total_elements = 0;
 473         atomic_set(&pool->counter, 0);
 474         pool->closing = 0;
 475         init_waitqueue_head(&pool->output_sleep);
 476
 477         pool->size = poolsize;
 478
 479         /* init statistics */
 480         pool->max_used = 0;
 481         return pool;
 482 }
 483
 484 /* remove memory pool */
 485 int snd_seq_pool_delete(struct snd_seq_pool **ppool)
 486 {
 487         struct snd_seq_pool *pool = *ppool;
 488
 489         *ppool = NULL;
 490         if (pool == NULL)
 491                 return 0;
 492         snd_seq_pool_done(pool);
 493         kfree(pool);
 494         return 0;
 495 }
 496
 497 /* initialize sequencer memory */
 498 int __init snd_sequencer_memory_init(void)
 499 {
 500         return 0;
 501 }
 502
 503 /* release sequencer memory */
 504 void __exit snd_sequencer_memory_done(void)
 505 {
 506 }
 507
 508
 509 /* exported to seq_clientmgr.c */
 510 void snd_seq_info_pool(struct snd_info_buffer *buffer,
 511                        struct snd_seq_pool *pool, char *space)
 512 {
 513         if (pool == NULL)
 514                 return;
 515         snd_iprintf(buffer, "%sPool size          : %d\n", space, pool->total_elements);
 516         snd_iprintf(buffer, "%sCells in use       : %d\n", space, atomic_read(&pool->counter));
 517         snd_iprintf(buffer, "%sPeak cells in use  : %d\n", space, pool->max_used);
 518         snd_iprintf(buffer, "%sAlloc success      : %d\n", space, pool->event_alloc_success);
 519         snd_iprintf(buffer, "%sAlloc failures     : %d\n", space, pool->event_alloc_failures);
 520 }