summaryrefslogtreecommitdiff
path: root/sound/core/seq/seq_memory.c
blob: d4c61ec9be13d7389addd27bc70acf58bda2eecc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
/*
 *  ALSA sequencer Memory Manager
 *  Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
 *                        Jaroslav Kysela <perex@perex.cz>
 *                2000 by Takashi Iwai <tiwai@suse.de>
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/init.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <linux/vmalloc.h>
#include <sound/core.h>

#include <sound/seq_kernel.h>
#include "seq_memory.h"
#include "seq_queue.h"
#include "seq_info.h"
#include "seq_lock.h"

static inline int snd_seq_pool_available(struct snd_seq_pool *pool)
{
	return pool->total_elements - atomic_read(&pool->counter);
}

static inline int snd_seq_output_ok(struct snd_seq_pool *pool)
{
	return snd_seq_pool_available(pool) >= pool->room;
}

/*
 * Variable length event:
 * The event like sysex uses variable length type.
 * The external data may be stored in three different formats.
 * 1) kernel space
 *    This is the normal case.
 *      ext.data.len = length
 *      ext.data.ptr = buffer pointer
 * 2) user space
 *    When an event is generated via read(), the external data is
 *    kept in user space until expanded.
 *      ext.data.len = length | SNDRV_SEQ_EXT_USRPTR
 *      ext.data.ptr = userspace pointer
 * 3) chained cells
 *    When the variable length event is enqueued (in prioq or fifo),
 *    the external data is decomposed to several cells.
 *      ext.data.len = length | SNDRV_SEQ_EXT_CHAINED
 *      ext.data.ptr = the additiona cell head
 *         -> cell.next -> cell.next -> ..
 */

/*
 * exported:
 * call dump function to expand external data.
 */

static int get_var_len(const struct snd_seq_event *event)
{
	if ((event->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
		return -EINVAL;

	return event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
}

int snd_seq_dump_var_event(const struct snd_seq_event *event,
			   snd_seq_dump_func_t func, void *private_data)
{
	int len, err;
	struct snd_seq_event_cell *cell;

	if ((len = get_var_len(event)) <= 0)
		return len;

	if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
		char buf[32];
		char __user *curptr = (char __force __user *)event->data.ext.ptr;
		while (len > 0) {
			int size = sizeof(buf);
			if (len < size)
				size = len;
			if (copy_from_user(buf, curptr, size))
				return -EFAULT;
			err = func(private_data, buf, size);
			if (err < 0)
				return err;
			curptr += size;
			len -= size;
		}
		return 0;
	}
	if (!(event->data.ext.len & SNDRV_SEQ_EXT_CHAINED))
		return func(private_data, event->data.ext.ptr, len);

	cell = (struct snd_seq_event_cell *)event->data.ext.ptr;
	for (; len > 0 && cell; cell = cell->next) {
		int size = sizeof(struct snd_seq_event);
		if (len < size)
			size = len;
		err = func(private_data, &cell->event, size);
		if (err < 0)
			return err;
		len -= size;
	}
	return 0;
}

EXPORT_SYMBOL(snd_seq_dump_var_event);


/*
 * exported:
 * expand the variable length event to linear buffer space.
 */

static int seq_copy_in_kernel(char **bufptr, const void *src, int size)
{
	memcpy(*bufptr, src, size);
	*bufptr += size;
	return 0;
}

static int seq_copy_in_user(char __user **bufptr, const void *src, int size)
{
	if (copy_to_user(*bufptr, src, size))
		return -EFAULT;
	*bufptr += size;
	return 0;
}

int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf,
			     int in_kernel, int size_aligned)
{
	int len, newlen;
	int err;

	if ((len = get_var_len(event)) < 0)
		return len;
	newlen = len;
	if (size_aligned > 0)
		newlen = roundup(len, size_aligned);
	if (count < newlen)
		return -EAGAIN;

	if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
		if (! in_kernel)
			return -EINVAL;
		if (copy_from_user(buf, (void __force __user *)event->data.ext.ptr, len))
			return -EFAULT;
		return newlen;
	}
	err = snd_seq_dump_var_event(event,
				     in_kernel ? (snd_seq_dump_func_t)seq_copy_in_kernel :
				     (snd_seq_dump_func_t)seq_copy_in_user,
				     &buf);
	return err < 0 ? err : newlen;
}

EXPORT_SYMBOL(snd_seq_expand_var_event);

/*
 * release this cell, free extended data if available
 */

static inline void free_cell(struct snd_seq_pool *pool,
			     struct snd_seq_event_cell *cell)
{
	cell->next = pool->free;
	pool->free = cell;
	atomic_dec(&pool->counter);
}

void snd_seq_cell_free(struct snd_seq_event_cell * cell)
{
	unsigned long flags;
	struct snd_seq_pool *pool;

	if (snd_BUG_ON(!cell))
		return;
	pool = cell->pool;
	if (snd_BUG_ON(!pool))
		return;

	spin_lock_irqsave(&pool->lock, flags);
	free_cell(pool, cell);
	if (snd_seq_ev_is_variable(&cell->event)) {
		if (cell->event.data.ext.len & SNDRV_SEQ_EXT_CHAINED) {
			struct snd_seq_event_cell *curp, *nextptr;
			curp = cell->event.data.ext.ptr;
			for (; curp; curp = nextptr) {
				nextptr = curp->next;
				curp->next = pool->free;
				free_cell(pool, curp);
			}
		}
	}
	if (waitqueue_active(&pool->output_sleep)) {
		/* has enough space now? */
		if (snd_seq_output_ok(pool))
			wake_up(&pool->output_sleep);
	}
	spin_unlock_irqrestore(&pool->lock, flags);
}


/*
 * allocate an event cell.
 */
static int snd_seq_cell_alloc(struct snd_seq_pool *pool,
			      struct snd_seq_event_cell **cellp,
			      int nonblock, struct file *file)
{
	struct snd_seq_event_cell *cell;
	unsigned long flags;
	int err = -EAGAIN;
	wait_queue_t wait;

	if (pool == NULL)
		return -EINVAL;

	*cellp = NULL;

	init_waitqueue_entry(&wait, current);
	spin_lock_irqsave(&pool->lock, flags);
	if (pool->ptr == NULL) {	/* not initialized */
		pr_debug("ALSA: seq: pool is not initialized\n");
		err = -EINVAL;
		goto __error;
	}
	while (pool->free == NULL && ! nonblock && ! pool->closing) {

		set_current_state(TASK_INTERRUPTIBLE);
		add_wait_queue(&pool->output_sleep, &wait);
		spin_unlock_irq(&pool->lock);
		schedule();
		spin_lock_irq(&pool->lock);
		remove_wait_queue(&pool->output_sleep, &wait);
		/* interrupted? */
		if (signal_pending(current)) {
			err = -ERESTARTSYS;
			goto __error;
		}
	}
	if (pool->closing) { /* closing.. */
		err = -ENOMEM;
		goto __error;
	}

	cell = pool->free;
	if (cell) {
		int used;
		pool->free = cell->next;
		atomic_inc(&pool->counter);
		used = atomic_read(&pool->counter);
		if (pool->max_used < used)
			pool->max_used = used;
		pool->event_alloc_success++;
		/* clear cell pointers */
		cell->next = NULL;
		err = 0;
	} else
		pool->event_alloc_failures++;
	*cellp = cell;

__error:
	spin_unlock_irqrestore(&pool->lock, flags);
	return err;
}


/*
 * duplicate the event to a cell.
 * if the event has external data, the data is decomposed to additional
 * cells.
 */
int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
		      struct snd_seq_event_cell **cellp, int nonblock,
		      struct file *file)
{
	int ncells, err;
	unsigned int extlen;
	struct snd_seq_event_cell *cell;

	*cellp = NULL;

	ncells = 0;
	extlen = 0;
	if (snd_seq_ev_is_variable(event)) {
		extlen = event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
		ncells = (extlen + sizeof(struct snd_seq_event) - 1) / sizeof(struct snd_seq_event);
	}
	if (ncells >= pool->total_elements)
		return -ENOMEM;

	err = snd_seq_cell_alloc(pool, &cell, nonblock, file);
	if (err < 0)
		return err;

	/* copy the event */
	cell->event = *event;

	/* decompose */
	if (snd_seq_ev_is_variable(event)) {
		int len = extlen;
		int is_chained = event->data.ext.len & SNDRV_SEQ_EXT_CHAINED;
		int is_usrptr = event->data.ext.len & SNDRV_SEQ_EXT_USRPTR;
		struct snd_seq_event_cell *src, *tmp, *tail;
		char *buf;

		cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED;
		cell->event.data.ext.ptr = NULL;

		src = (struct snd_seq_event_cell *)event->data.ext.ptr;
		buf = (char *)event->data.ext.ptr;
		tail = NULL;

		while (ncells-- > 0) {
			int size = sizeof(struct snd_seq_event);
			if (len < size)
				size = len;
			err = snd_seq_cell_alloc(pool, &tmp, nonblock, file);
			if (err < 0)
				goto __error;
			if (cell->event.data.ext.ptr == NULL)
				cell->event.data.ext.ptr = tmp;
			if (tail)
				tail->next = tmp;
			tail = tmp;
			/* copy chunk */
			if (is_chained && src) {
				tmp->event = src->event;
				src = src->next;
			} else if (is_usrptr) {
				if (copy_from_user(&tmp->event, (char __force __user *)buf, size)) {
					err = -EFAULT;
					goto __error;
				}
			} else {
				memcpy(&tmp->event, buf, size);
			}
			buf += size;
			len -= size;
		}
	}

	*cellp = cell;
	return 0;

__error:
	snd_seq_cell_free(cell);
	return err;
}
  

/* poll wait */
int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
			   poll_table *wait)
{
	poll_wait(file, &pool->output_sleep, wait);
	return snd_seq_output_ok(pool);
}


/* allocate room specified number of events */
int snd_seq_pool_init(struct snd_seq_pool *pool)
{
	int cell;
	struct snd_seq_event_cell *cellptr;
	unsigned long flags;

	if (snd_BUG_ON(!pool))
		return -EINVAL;

	cellptr = vmalloc(sizeof(struct snd_seq_event_cell) * pool->size);
	if (!cellptr)
		return -ENOMEM;

	/* add new cells to the free cell list */
	spin_lock_irqsave(&pool->lock, flags);
	if (pool->ptr) {
		spin_unlock_irqrestore(&pool->lock, flags);
		vfree(cellptr);
		return 0;
	}

	pool->ptr = cellptr;
	pool->free = NULL;

	for (cell = 0; cell < pool->size; cell++) {
		cellptr = pool->ptr + cell;
		cellptr->pool = pool;
		cellptr->next = pool->free;
		pool->free = cellptr;
	}
	pool->room = (pool->size + 1) / 2;

	/* init statistics */
	pool->max_used = 0;
	pool->total_elements = pool->size;
	spin_unlock_irqrestore(&pool->lock, flags);
	return 0;
}

/* refuse the further insertion to the pool */
void snd_seq_pool_mark_closing(struct snd_seq_pool *pool)
{
	unsigned long flags;

	if (snd_BUG_ON(!pool))
		return;
	spin_lock_irqsave(&pool->lock, flags);
	pool->closing = 1;
	spin_unlock_irqrestore(&pool->lock, flags);
}

/* remove events */
int snd_seq_pool_done(struct snd_seq_pool *pool)
{
	unsigned long flags;
	struct snd_seq_event_cell *ptr;

	if (snd_BUG_ON(!pool))
		return -EINVAL;

	/* wait for closing all threads */
	if (waitqueue_active(&pool->output_sleep))
		wake_up(&pool->output_sleep);

	while (atomic_read(&pool->counter) > 0)
		schedule_timeout_uninterruptible(1);
	
	/* release all resources */
	spin_lock_irqsave(&pool->lock, flags);
	ptr = pool->ptr;
	pool->ptr = NULL;
	pool->free = NULL;
	pool->total_elements = 0;
	spin_unlock_irqrestore(&pool->lock, flags);

	vfree(ptr);

	spin_lock_irqsave(&pool->lock, flags);
	pool->closing = 0;
	spin_unlock_irqrestore(&pool->lock, flags);

	return 0;
}


/* init new memory pool */
struct snd_seq_pool *snd_seq_pool_new(int poolsize)
{
	struct snd_seq_pool *pool;

	/* create pool block */
	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
	if (!pool)
		return NULL;
	spin_lock_init(&pool->lock);
	pool->ptr = NULL;
	pool->free = NULL;
	pool->total_elements = 0;
	atomic_set(&pool->counter, 0);
	pool->closing = 0;
	init_waitqueue_head(&pool->output_sleep);
	
	pool->size = poolsize;

	/* init statistics */
	pool->max_used = 0;
	return pool;
}

/* remove memory pool */
int snd_seq_pool_delete(struct snd_seq_pool **ppool)
{
	struct snd_seq_pool *pool = *ppool;

	*ppool = NULL;
	if (pool == NULL)
		return 0;
	snd_seq_pool_mark_closing(pool);
	snd_seq_pool_done(pool);
	kfree(pool);
	return 0;
}

/* initialize sequencer memory */
int __init snd_sequencer_memory_init(void)
{
	return 0;
}

/* release sequencer memory */
void __exit snd_sequencer_memory_done(void)
{
}


/* exported to seq_clientmgr.c */
void snd_seq_info_pool(struct snd_info_buffer *buffer,
		       struct snd_seq_pool *pool, char *space)
{
	if (pool == NULL)
		return;
	snd_iprintf(buffer, "%sPool size          : %d\n", space, pool->total_elements);
	snd_iprintf(buffer, "%sCells in use       : %d\n", space, atomic_read(&pool->counter));
	snd_iprintf(buffer, "%sPeak cells in use  : %d\n", space, pool->max_used);
	snd_iprintf(buffer, "%sAlloc success      : %d\n", space, pool->event_alloc_success);
	snd_iprintf(buffer, "%sAlloc failures     : %d\n", space, pool->event_alloc_failures);
}