~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/sound/core/seq/seq_memory.c

Version: ~ [ linux-5.18-rc6 ] ~ [ linux-5.17.6 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.38 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.114 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.192 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.241 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.277 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.312 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.302 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0-or-later
  2 /*
  3  *  ALSA sequencer Memory Manager
  4  *  Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
  5  *                        Jaroslav Kysela <perex@perex.cz>
  6  *                2000 by Takashi Iwai <tiwai@suse.de>
  7  */
  8 
  9 #include <linux/init.h>
 10 #include <linux/export.h>
 11 #include <linux/slab.h>
 12 #include <linux/sched/signal.h>
 13 #include <linux/mm.h>
 14 #include <sound/core.h>
 15 
 16 #include <sound/seq_kernel.h>
 17 #include "seq_memory.h"
 18 #include "seq_queue.h"
 19 #include "seq_info.h"
 20 #include "seq_lock.h"
 21 
 22 static inline int snd_seq_pool_available(struct snd_seq_pool *pool)
 23 {
 24         return pool->total_elements - atomic_read(&pool->counter);
 25 }
 26 
 27 static inline int snd_seq_output_ok(struct snd_seq_pool *pool)
 28 {
 29         return snd_seq_pool_available(pool) >= pool->room;
 30 }
 31 
 32 /*
 33  * Variable length event:
 34  * The event like sysex uses variable length type.
 35  * The external data may be stored in three different formats.
 36  * 1) kernel space
 37  *    This is the normal case.
 38  *      ext.data.len = length
 39  *      ext.data.ptr = buffer pointer
 40  * 2) user space
 41  *    When an event is generated via read(), the external data is
 42  *    kept in user space until expanded.
 43  *      ext.data.len = length | SNDRV_SEQ_EXT_USRPTR
 44  *      ext.data.ptr = userspace pointer
 45  * 3) chained cells
 46  *    When the variable length event is enqueued (in prioq or fifo),
 47  *    the external data is decomposed to several cells.
 48  *      ext.data.len = length | SNDRV_SEQ_EXT_CHAINED
 49  *      ext.data.ptr = the additiona cell head
 50  *         -> cell.next -> cell.next -> ..
 51  */
 52 
 53 /*
 54  * exported:
 55  * call dump function to expand external data.
 56  */
 57 
 58 static int get_var_len(const struct snd_seq_event *event)
 59 {
 60         if ((event->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
 61                 return -EINVAL;
 62 
 63         return event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
 64 }
 65 
 66 int snd_seq_dump_var_event(const struct snd_seq_event *event,
 67                            snd_seq_dump_func_t func, void *private_data)
 68 {
 69         int len, err;
 70         struct snd_seq_event_cell *cell;
 71 
 72         if ((len = get_var_len(event)) <= 0)
 73                 return len;
 74 
 75         if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
 76                 char buf[32];
 77                 char __user *curptr = (char __force __user *)event->data.ext.ptr;
 78                 while (len > 0) {
 79                         int size = sizeof(buf);
 80                         if (len < size)
 81                                 size = len;
 82                         if (copy_from_user(buf, curptr, size))
 83                                 return -EFAULT;
 84                         err = func(private_data, buf, size);
 85                         if (err < 0)
 86                                 return err;
 87                         curptr += size;
 88                         len -= size;
 89                 }
 90                 return 0;
 91         }
 92         if (!(event->data.ext.len & SNDRV_SEQ_EXT_CHAINED))
 93                 return func(private_data, event->data.ext.ptr, len);
 94 
 95         cell = (struct snd_seq_event_cell *)event->data.ext.ptr;
 96         for (; len > 0 && cell; cell = cell->next) {
 97                 int size = sizeof(struct snd_seq_event);
 98                 if (len < size)
 99                         size = len;
100                 err = func(private_data, &cell->event, size);
101                 if (err < 0)
102                         return err;
103                 len -= size;
104         }
105         return 0;
106 }
107 EXPORT_SYMBOL(snd_seq_dump_var_event);
108 
109 
110 /*
111  * exported:
112  * expand the variable length event to linear buffer space.
113  */
114 
115 static int seq_copy_in_kernel(char **bufptr, const void *src, int size)
116 {
117         memcpy(*bufptr, src, size);
118         *bufptr += size;
119         return 0;
120 }
121 
122 static int seq_copy_in_user(char __user **bufptr, const void *src, int size)
123 {
124         if (copy_to_user(*bufptr, src, size))
125                 return -EFAULT;
126         *bufptr += size;
127         return 0;
128 }
129 
130 int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf,
131                              int in_kernel, int size_aligned)
132 {
133         int len, newlen;
134         int err;
135 
136         if ((len = get_var_len(event)) < 0)
137                 return len;
138         newlen = len;
139         if (size_aligned > 0)
140                 newlen = roundup(len, size_aligned);
141         if (count < newlen)
142                 return -EAGAIN;
143 
144         if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
145                 if (! in_kernel)
146                         return -EINVAL;
147                 if (copy_from_user(buf, (void __force __user *)event->data.ext.ptr, len))
148                         return -EFAULT;
149                 return newlen;
150         }
151         err = snd_seq_dump_var_event(event,
152                                      in_kernel ? (snd_seq_dump_func_t)seq_copy_in_kernel :
153                                      (snd_seq_dump_func_t)seq_copy_in_user,
154                                      &buf);
155         return err < 0 ? err : newlen;
156 }
157 EXPORT_SYMBOL(snd_seq_expand_var_event);
158 
159 /*
160  * release this cell, free extended data if available
161  */
162 
163 static inline void free_cell(struct snd_seq_pool *pool,
164                              struct snd_seq_event_cell *cell)
165 {
166         cell->next = pool->free;
167         pool->free = cell;
168         atomic_dec(&pool->counter);
169 }
170 
171 void snd_seq_cell_free(struct snd_seq_event_cell * cell)
172 {
173         unsigned long flags;
174         struct snd_seq_pool *pool;
175 
176         if (snd_BUG_ON(!cell))
177                 return;
178         pool = cell->pool;
179         if (snd_BUG_ON(!pool))
180                 return;
181 
182         spin_lock_irqsave(&pool->lock, flags);
183         free_cell(pool, cell);
184         if (snd_seq_ev_is_variable(&cell->event)) {
185                 if (cell->event.data.ext.len & SNDRV_SEQ_EXT_CHAINED) {
186                         struct snd_seq_event_cell *curp, *nextptr;
187                         curp = cell->event.data.ext.ptr;
188                         for (; curp; curp = nextptr) {
189                                 nextptr = curp->next;
190                                 curp->next = pool->free;
191                                 free_cell(pool, curp);
192                         }
193                 }
194         }
195         if (waitqueue_active(&pool->output_sleep)) {
196                 /* has enough space now? */
197                 if (snd_seq_output_ok(pool))
198                         wake_up(&pool->output_sleep);
199         }
200         spin_unlock_irqrestore(&pool->lock, flags);
201 }
202 
203 
204 /*
205  * allocate an event cell.
206  */
207 static int snd_seq_cell_alloc(struct snd_seq_pool *pool,
208                               struct snd_seq_event_cell **cellp,
209                               int nonblock, struct file *file,
210                               struct mutex *mutexp)
211 {
212         struct snd_seq_event_cell *cell;
213         unsigned long flags;
214         int err = -EAGAIN;
215         wait_queue_entry_t wait;
216 
217         if (pool == NULL)
218                 return -EINVAL;
219 
220         *cellp = NULL;
221 
222         init_waitqueue_entry(&wait, current);
223         spin_lock_irqsave(&pool->lock, flags);
224         if (pool->ptr == NULL) {        /* not initialized */
225                 pr_debug("ALSA: seq: pool is not initialized\n");
226                 err = -EINVAL;
227                 goto __error;
228         }
229         while (pool->free == NULL && ! nonblock && ! pool->closing) {
230 
231                 set_current_state(TASK_INTERRUPTIBLE);
232                 add_wait_queue(&pool->output_sleep, &wait);
233                 spin_unlock_irqrestore(&pool->lock, flags);
234                 if (mutexp)
235                         mutex_unlock(mutexp);
236                 schedule();
237                 if (mutexp)
238                         mutex_lock(mutexp);
239                 spin_lock_irqsave(&pool->lock, flags);
240                 remove_wait_queue(&pool->output_sleep, &wait);
241                 /* interrupted? */
242                 if (signal_pending(current)) {
243                         err = -ERESTARTSYS;
244                         goto __error;
245                 }
246         }
247         if (pool->closing) { /* closing.. */
248                 err = -ENOMEM;
249                 goto __error;
250         }
251 
252         cell = pool->free;
253         if (cell) {
254                 int used;
255                 pool->free = cell->next;
256                 atomic_inc(&pool->counter);
257                 used = atomic_read(&pool->counter);
258                 if (pool->max_used < used)
259                         pool->max_used = used;
260                 pool->event_alloc_success++;
261                 /* clear cell pointers */
262                 cell->next = NULL;
263                 err = 0;
264         } else
265                 pool->event_alloc_failures++;
266         *cellp = cell;
267 
268 __error:
269         spin_unlock_irqrestore(&pool->lock, flags);
270         return err;
271 }
272 
273 
274 /*
275  * duplicate the event to a cell.
276  * if the event has external data, the data is decomposed to additional
277  * cells.
278  */
279 int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
280                       struct snd_seq_event_cell **cellp, int nonblock,
281                       struct file *file, struct mutex *mutexp)
282 {
283         int ncells, err;
284         unsigned int extlen;
285         struct snd_seq_event_cell *cell;
286 
287         *cellp = NULL;
288 
289         ncells = 0;
290         extlen = 0;
291         if (snd_seq_ev_is_variable(event)) {
292                 extlen = event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
293                 ncells = (extlen + sizeof(struct snd_seq_event) - 1) / sizeof(struct snd_seq_event);
294         }
295         if (ncells >= pool->total_elements)
296                 return -ENOMEM;
297 
298         err = snd_seq_cell_alloc(pool, &cell, nonblock, file, mutexp);
299         if (err < 0)
300                 return err;
301 
302         /* copy the event */
303         cell->event = *event;
304 
305         /* decompose */
306         if (snd_seq_ev_is_variable(event)) {
307                 int len = extlen;
308                 int is_chained = event->data.ext.len & SNDRV_SEQ_EXT_CHAINED;
309                 int is_usrptr = event->data.ext.len & SNDRV_SEQ_EXT_USRPTR;
310                 struct snd_seq_event_cell *src, *tmp, *tail;
311                 char *buf;
312 
313                 cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED;
314                 cell->event.data.ext.ptr = NULL;
315 
316                 src = (struct snd_seq_event_cell *)event->data.ext.ptr;
317                 buf = (char *)event->data.ext.ptr;
318                 tail = NULL;
319 
320                 while (ncells-- > 0) {
321                         int size = sizeof(struct snd_seq_event);
322                         if (len < size)
323                                 size = len;
324                         err = snd_seq_cell_alloc(pool, &tmp, nonblock, file,
325                                                  mutexp);
326                         if (err < 0)
327                                 goto __error;
328                         if (cell->event.data.ext.ptr == NULL)
329                                 cell->event.data.ext.ptr = tmp;
330                         if (tail)
331                                 tail->next = tmp;
332                         tail = tmp;
333                         /* copy chunk */
334                         if (is_chained && src) {
335                                 tmp->event = src->event;
336                                 src = src->next;
337                         } else if (is_usrptr) {
338                                 if (copy_from_user(&tmp->event, (char __force __user *)buf, size)) {
339                                         err = -EFAULT;
340                                         goto __error;
341                                 }
342                         } else {
343                                 memcpy(&tmp->event, buf, size);
344                         }
345                         buf += size;
346                         len -= size;
347                 }
348         }
349 
350         *cellp = cell;
351         return 0;
352 
353 __error:
354         snd_seq_cell_free(cell);
355         return err;
356 }
357   
358 
359 /* poll wait */
360 int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
361                            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(struct snd_seq_pool *pool)
370 {
371         int cell;
372         struct snd_seq_event_cell *cellptr;
373 
374         if (snd_BUG_ON(!pool))
375                 return -EINVAL;
376 
377         cellptr = kvmalloc_array(sizeof(struct snd_seq_event_cell), pool->size,
378                                  GFP_KERNEL);
379         if (!cellptr)
380                 return -ENOMEM;
381 
382         /* add new cells to the free cell list */
383         spin_lock_irq(&pool->lock);
384         if (pool->ptr) {
385                 spin_unlock_irq(&pool->lock);
386                 kvfree(cellptr);
387                 return 0;
388         }
389 
390         pool->ptr = cellptr;
391         pool->free = NULL;
392 
393         for (cell = 0; cell < pool->size; cell++) {
394                 cellptr = pool->ptr + cell;
395                 cellptr->pool = pool;
396                 cellptr->next = pool->free;
397                 pool->free = cellptr;
398         }
399         pool->room = (pool->size + 1) / 2;
400 
401         /* init statistics */
402         pool->max_used = 0;
403         pool->total_elements = pool->size;
404         spin_unlock_irq(&pool->lock);
405         return 0;
406 }
407 
408 /* refuse the further insertion to the pool */
409 void snd_seq_pool_mark_closing(struct snd_seq_pool *pool)
410 {
411         unsigned long flags;
412 
413         if (snd_BUG_ON(!pool))
414                 return;
415         spin_lock_irqsave(&pool->lock, flags);
416         pool->closing = 1;
417         spin_unlock_irqrestore(&pool->lock, flags);
418 }
419 
420 /* remove events */
421 int snd_seq_pool_done(struct snd_seq_pool *pool)
422 {
423         struct snd_seq_event_cell *ptr;
424 
425         if (snd_BUG_ON(!pool))
426                 return -EINVAL;
427 
428         /* wait for closing all threads */
429         if (waitqueue_active(&pool->output_sleep))
430                 wake_up(&pool->output_sleep);
431 
432         while (atomic_read(&pool->counter) > 0)
433                 schedule_timeout_uninterruptible(1);
434         
435         /* release all resources */
436         spin_lock_irq(&pool->lock);
437         ptr = pool->ptr;
438         pool->ptr = NULL;
439         pool->free = NULL;
440         pool->total_elements = 0;
441         spin_unlock_irq(&pool->lock);
442 
443         kvfree(ptr);
444 
445         spin_lock_irq(&pool->lock);
446         pool->closing = 0;
447         spin_unlock_irq(&pool->lock);
448 
449         return 0;
450 }
451 
452 
453 /* init new memory pool */
454 struct snd_seq_pool *snd_seq_pool_new(int poolsize)
455 {
456         struct snd_seq_pool *pool;
457 
458         /* create pool block */
459         pool = kzalloc(sizeof(*pool), GFP_KERNEL);
460         if (!pool)
461                 return NULL;
462         spin_lock_init(&pool->lock);
463         pool->ptr = NULL;
464         pool->free = NULL;
465         pool->total_elements = 0;
466         atomic_set(&pool->counter, 0);
467         pool->closing = 0;
468         init_waitqueue_head(&pool->output_sleep);
469         
470         pool->size = poolsize;
471 
472         /* init statistics */
473         pool->max_used = 0;
474         return pool;
475 }
476 
477 /* remove memory pool */
478 int snd_seq_pool_delete(struct snd_seq_pool **ppool)
479 {
480         struct snd_seq_pool *pool = *ppool;
481 
482         *ppool = NULL;
483         if (pool == NULL)
484                 return 0;
485         snd_seq_pool_mark_closing(pool);
486         snd_seq_pool_done(pool);
487         kfree(pool);
488         return 0;
489 }
490 
491 /* exported to seq_clientmgr.c */
492 void snd_seq_info_pool(struct snd_info_buffer *buffer,
493                        struct snd_seq_pool *pool, char *space)
494 {
495         if (pool == NULL)
496                 return;
497         snd_iprintf(buffer, "%sPool size          : %d\n", space, pool->total_elements);
498         snd_iprintf(buffer, "%sCells in use       : %d\n", space, atomic_read(&pool->counter));
499         snd_iprintf(buffer, "%sPeak cells in use  : %d\n", space, pool->max_used);
500         snd_iprintf(buffer, "%sAlloc success      : %d\n", space, pool->event_alloc_success);
501         snd_iprintf(buffer, "%sAlloc failures     : %d\n", space, pool->event_alloc_failures);
502 }
503 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp