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Linux/sound/core/seq/seq_memory.c

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  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         } 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 __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                               struct mutex *mutexp)
226 {
227         struct snd_seq_event_cell *cell;
228         unsigned long flags;
229         int err = -EAGAIN;
230         wait_queue_t wait;
231 
232         if (pool == NULL)
233                 return -EINVAL;
234 
235         *cellp = NULL;
236 
237         init_waitqueue_entry(&wait, current);
238         spin_lock_irqsave(&pool->lock, flags);
239         if (pool->ptr == NULL) {        /* not initialized */
240                 pr_debug("ALSA: seq: pool is not initialized\n");
241                 err = -EINVAL;
242                 goto __error;
243         }
244         while (pool->free == NULL && ! nonblock && ! pool->closing) {
245 
246                 set_current_state(TASK_INTERRUPTIBLE);
247                 add_wait_queue(&pool->output_sleep, &wait);
248                 spin_unlock_irq(&pool->lock);
249                 if (mutexp)
250                         mutex_unlock(mutexp);
251                 schedule();
252                 if (mutexp)
253                         mutex_lock(mutexp);
254                 spin_lock_irq(&pool->lock);
255                 remove_wait_queue(&pool->output_sleep, &wait);
256                 /* interrupted? */
257                 if (signal_pending(current)) {
258                         err = -ERESTARTSYS;
259                         goto __error;
260                 }
261         }
262         if (pool->closing) { /* closing.. */
263                 err = -ENOMEM;
264                 goto __error;
265         }
266 
267         cell = pool->free;
268         if (cell) {
269                 int used;
270                 pool->free = cell->next;
271                 atomic_inc(&pool->counter);
272                 used = atomic_read(&pool->counter);
273                 if (pool->max_used < used)
274                         pool->max_used = used;
275                 pool->event_alloc_success++;
276                 /* clear cell pointers */
277                 cell->next = NULL;
278                 err = 0;
279         } else
280                 pool->event_alloc_failures++;
281         *cellp = cell;
282 
283 __error:
284         spin_unlock_irqrestore(&pool->lock, flags);
285         return err;
286 }
287 
288 
289 /*
290  * duplicate the event to a cell.
291  * if the event has external data, the data is decomposed to additional
292  * cells.
293  */
294 int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
295                       struct snd_seq_event_cell **cellp, int nonblock,
296                       struct file *file, struct mutex *mutexp)
297 {
298         int ncells, err;
299         unsigned int extlen;
300         struct snd_seq_event_cell *cell;
301 
302         *cellp = NULL;
303 
304         ncells = 0;
305         extlen = 0;
306         if (snd_seq_ev_is_variable(event)) {
307                 extlen = event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
308                 ncells = (extlen + sizeof(struct snd_seq_event) - 1) / sizeof(struct snd_seq_event);
309         }
310         if (ncells >= pool->total_elements)
311                 return -ENOMEM;
312 
313         err = snd_seq_cell_alloc(pool, &cell, nonblock, file, mutexp);
314         if (err < 0)
315                 return err;
316 
317         /* copy the event */
318         cell->event = *event;
319 
320         /* decompose */
321         if (snd_seq_ev_is_variable(event)) {
322                 int len = extlen;
323                 int is_chained = event->data.ext.len & SNDRV_SEQ_EXT_CHAINED;
324                 int is_usrptr = event->data.ext.len & SNDRV_SEQ_EXT_USRPTR;
325                 struct snd_seq_event_cell *src, *tmp, *tail;
326                 char *buf;
327 
328                 cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED;
329                 cell->event.data.ext.ptr = NULL;
330 
331                 src = (struct snd_seq_event_cell *)event->data.ext.ptr;
332                 buf = (char *)event->data.ext.ptr;
333                 tail = NULL;
334 
335                 while (ncells-- > 0) {
336                         int size = sizeof(struct snd_seq_event);
337                         if (len < size)
338                                 size = len;
339                         err = snd_seq_cell_alloc(pool, &tmp, nonblock, file,
340                                                  mutexp);
341                         if (err < 0)
342                                 goto __error;
343                         if (cell->event.data.ext.ptr == NULL)
344                                 cell->event.data.ext.ptr = tmp;
345                         if (tail)
346                                 tail->next = tmp;
347                         tail = tmp;
348                         /* copy chunk */
349                         if (is_chained && src) {
350                                 tmp->event = src->event;
351                                 src = src->next;
352                         } else if (is_usrptr) {
353                                 if (copy_from_user(&tmp->event, (char __force __user *)buf, size)) {
354                                         err = -EFAULT;
355                                         goto __error;
356                                 }
357                         } else {
358                                 memcpy(&tmp->event, buf, size);
359                         }
360                         buf += size;
361                         len -= size;
362                 }
363         }
364 
365         *cellp = cell;
366         return 0;
367 
368 __error:
369         snd_seq_cell_free(cell);
370         return err;
371 }
372   
373 
374 /* poll wait */
375 int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
376                            poll_table *wait)
377 {
378         poll_wait(file, &pool->output_sleep, wait);
379         return snd_seq_output_ok(pool);
380 }
381 
382 
383 /* allocate room specified number of events */
384 int snd_seq_pool_init(struct snd_seq_pool *pool)
385 {
386         int cell;
387         struct snd_seq_event_cell *cellptr;
388         unsigned long flags;
389 
390         if (snd_BUG_ON(!pool))
391                 return -EINVAL;
392 
393         cellptr = vmalloc(sizeof(struct snd_seq_event_cell) * pool->size);
394         if (!cellptr)
395                 return -ENOMEM;
396 
397         /* add new cells to the free cell list */
398         spin_lock_irqsave(&pool->lock, flags);
399         if (pool->ptr) {
400                 spin_unlock_irqrestore(&pool->lock, flags);
401                 vfree(cellptr);
402                 return 0;
403         }
404 
405         pool->ptr = cellptr;
406         pool->free = NULL;
407 
408         for (cell = 0; cell < pool->size; cell++) {
409                 cellptr = pool->ptr + cell;
410                 cellptr->pool = pool;
411                 cellptr->next = pool->free;
412                 pool->free = cellptr;
413         }
414         pool->room = (pool->size + 1) / 2;
415 
416         /* init statistics */
417         pool->max_used = 0;
418         pool->total_elements = pool->size;
419         spin_unlock_irqrestore(&pool->lock, flags);
420         return 0;
421 }
422 
423 /* refuse the further insertion to the pool */
424 void snd_seq_pool_mark_closing(struct snd_seq_pool *pool)
425 {
426         unsigned long flags;
427 
428         if (snd_BUG_ON(!pool))
429                 return;
430         spin_lock_irqsave(&pool->lock, flags);
431         pool->closing = 1;
432         spin_unlock_irqrestore(&pool->lock, flags);
433 }
434 
435 /* remove events */
436 int snd_seq_pool_done(struct snd_seq_pool *pool)
437 {
438         unsigned long flags;
439         struct snd_seq_event_cell *ptr;
440 
441         if (snd_BUG_ON(!pool))
442                 return -EINVAL;
443 
444         /* wait for closing all threads */
445         if (waitqueue_active(&pool->output_sleep))
446                 wake_up(&pool->output_sleep);
447 
448         while (atomic_read(&pool->counter) > 0)
449                 schedule_timeout_uninterruptible(1);
450         
451         /* release all resources */
452         spin_lock_irqsave(&pool->lock, flags);
453         ptr = pool->ptr;
454         pool->ptr = NULL;
455         pool->free = NULL;
456         pool->total_elements = 0;
457         spin_unlock_irqrestore(&pool->lock, flags);
458 
459         vfree(ptr);
460 
461         spin_lock_irqsave(&pool->lock, flags);
462         pool->closing = 0;
463         spin_unlock_irqrestore(&pool->lock, flags);
464 
465         return 0;
466 }
467 
468 
469 /* init new memory pool */
470 struct snd_seq_pool *snd_seq_pool_new(int poolsize)
471 {
472         struct snd_seq_pool *pool;
473 
474         /* create pool block */
475         pool = kzalloc(sizeof(*pool), GFP_KERNEL);
476         if (!pool)
477                 return NULL;
478         spin_lock_init(&pool->lock);
479         pool->ptr = NULL;
480         pool->free = NULL;
481         pool->total_elements = 0;
482         atomic_set(&pool->counter, 0);
483         pool->closing = 0;
484         init_waitqueue_head(&pool->output_sleep);
485         
486         pool->size = poolsize;
487 
488         /* init statistics */
489         pool->max_used = 0;
490         return pool;
491 }
492 
493 /* remove memory pool */
494 int snd_seq_pool_delete(struct snd_seq_pool **ppool)
495 {
496         struct snd_seq_pool *pool = *ppool;
497 
498         *ppool = NULL;
499         if (pool == NULL)
500                 return 0;
501         snd_seq_pool_mark_closing(pool);
502         snd_seq_pool_done(pool);
503         kfree(pool);
504         return 0;
505 }
506 
507 /* initialize sequencer memory */
508 int __init snd_sequencer_memory_init(void)
509 {
510         return 0;
511 }
512 
513 /* release sequencer memory */
514 void __exit snd_sequencer_memory_done(void)
515 {
516 }
517 
518 
519 /* exported to seq_clientmgr.c */
520 void snd_seq_info_pool(struct snd_info_buffer *buffer,
521                        struct snd_seq_pool *pool, char *space)
522 {
523         if (pool == NULL)
524                 return;
525         snd_iprintf(buffer, "%sPool size          : %d\n", space, pool->total_elements);
526         snd_iprintf(buffer, "%sCells in use       : %d\n", space, atomic_read(&pool->counter));
527         snd_iprintf(buffer, "%sPeak cells in use  : %d\n", space, pool->max_used);
528         snd_iprintf(buffer, "%sAlloc success      : %d\n", space, pool->event_alloc_success);
529         snd_iprintf(buffer, "%sAlloc failures     : %d\n", space, pool->event_alloc_failures);
530 }
531 

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