summaryrefslogtreecommitdiff
path: root/sound/core/pcm_memory.c
blob: ea3941f8666b2dbc8c555955cb9e6f6f4cae32b7 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Digital Audio (PCM) abstract layer
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 */

#include <linux/io.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/moduleparam.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/info.h>
#include <sound/initval.h>
#include "pcm_local.h"

static int preallocate_dma = 1;
module_param(preallocate_dma, int, 0444);
MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");

static int maximum_substreams = 4;
module_param(maximum_substreams, int, 0444);
MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");

static const size_t snd_minimum_buffer = 16384;

static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL;
module_param(max_alloc_per_card, ulong, 0644);
MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card.");

static void __update_allocated_size(struct snd_card *card, ssize_t bytes)
{
	card->total_pcm_alloc_bytes += bytes;
}

static void update_allocated_size(struct snd_card *card, ssize_t bytes)
{
	guard(mutex)(&card->memory_mutex);
	__update_allocated_size(card, bytes);
}

static void decrease_allocated_size(struct snd_card *card, size_t bytes)
{
	guard(mutex)(&card->memory_mutex);
	WARN_ON(card->total_pcm_alloc_bytes < bytes);
	__update_allocated_size(card, -(ssize_t)bytes);
}

static int do_alloc_pages(struct snd_card *card, int type, struct device *dev,
			  int str, size_t size, struct snd_dma_buffer *dmab)
{
	enum dma_data_direction dir;
	int err;

	/* check and reserve the requested size */
	scoped_guard(mutex, &card->memory_mutex) {
		if (max_alloc_per_card &&
		    card->total_pcm_alloc_bytes + size > max_alloc_per_card)
			return -ENOMEM;
		__update_allocated_size(card, size);
	}

	if (str == SNDRV_PCM_STREAM_PLAYBACK)
		dir = DMA_TO_DEVICE;
	else
		dir = DMA_FROM_DEVICE;
	err = snd_dma_alloc_dir_pages(type, dev, dir, size, dmab);
	if (!err) {
		/* the actual allocation size might be bigger than requested,
		 * and we need to correct the account
		 */
		if (dmab->bytes != size)
			update_allocated_size(card, dmab->bytes - size);
	} else {
		/* take back on allocation failure */
		decrease_allocated_size(card, size);
	}
	return err;
}

static void do_free_pages(struct snd_card *card, struct snd_dma_buffer *dmab)
{
	if (!dmab->area)
		return;
	decrease_allocated_size(card, dmab->bytes);
	snd_dma_free_pages(dmab);
	dmab->area = NULL;
}

/*
 * try to allocate as the large pages as possible.
 * stores the resultant memory size in *res_size.
 *
 * the minimum size is snd_minimum_buffer.  it should be power of 2.
 */
static int preallocate_pcm_pages(struct snd_pcm_substream *substream,
				 size_t size, bool no_fallback)
{
	struct snd_dma_buffer *dmab = &substream->dma_buffer;
	struct snd_card *card = substream->pcm->card;
	size_t orig_size = size;
	int err;

	do {
		err = do_alloc_pages(card, dmab->dev.type, dmab->dev.dev,
				     substream->stream, size, dmab);
		if (err != -ENOMEM)
			return err;
		if (no_fallback)
			break;
		size >>= 1;
	} while (size >= snd_minimum_buffer);
	dmab->bytes = 0; /* tell error */
	pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
		substream->pcm->card->number, substream->pcm->device,
		substream->stream ? 'c' : 'p', substream->number,
		substream->pcm->name, orig_size);
	return -ENOMEM;
}

/**
 * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
 * @substream: the pcm substream instance
 *
 * Releases the pre-allocated buffer of the given substream.
 */
void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
{
	do_free_pages(substream->pcm->card, &substream->dma_buffer);
}

/**
 * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
 * @pcm: the pcm instance
 *
 * Releases all the pre-allocated buffers on the given pcm.
 */
void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
{
	struct snd_pcm_substream *substream;
	int stream;

	for_each_pcm_substream(pcm, stream, substream)
		snd_pcm_lib_preallocate_free(substream);
}
EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);

#ifdef CONFIG_SND_VERBOSE_PROCFS
/*
 * read callback for prealloc proc file
 *
 * prints the current allocated size in kB.
 */
static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
					      struct snd_info_buffer *buffer)
{
	struct snd_pcm_substream *substream = entry->private_data;
	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
}

/*
 * read callback for prealloc_max proc file
 *
 * prints the maximum allowed size in kB.
 */
static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
						  struct snd_info_buffer *buffer)
{
	struct snd_pcm_substream *substream = entry->private_data;
	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
}

/*
 * write callback for prealloc proc file
 *
 * accepts the preallocation size in kB.
 */
static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
					       struct snd_info_buffer *buffer)
{
	struct snd_pcm_substream *substream = entry->private_data;
	struct snd_card *card = substream->pcm->card;
	char line[64], str[64];
	unsigned long size;
	struct snd_dma_buffer new_dmab;

	guard(mutex)(&substream->pcm->open_mutex);
	if (substream->runtime) {
		buffer->error = -EBUSY;
		return;
	}
	if (!snd_info_get_line(buffer, line, sizeof(line))) {
		snd_info_get_str(str, line, sizeof(str));
		buffer->error = kstrtoul(str, 10, &size);
		if (buffer->error != 0)
			return;
		size *= 1024;
		if ((size != 0 && size < 8192) || size > substream->dma_max) {
			buffer->error = -EINVAL;
			return;
		}
		if (substream->dma_buffer.bytes == size)
			return;
		memset(&new_dmab, 0, sizeof(new_dmab));
		new_dmab.dev = substream->dma_buffer.dev;
		if (size > 0) {
			if (do_alloc_pages(card,
					   substream->dma_buffer.dev.type,
					   substream->dma_buffer.dev.dev,
					   substream->stream,
					   size, &new_dmab) < 0) {
				buffer->error = -ENOMEM;
				pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %lu\n",
					 substream->pcm->card->number, substream->pcm->device,
					 substream->stream ? 'c' : 'p', substream->number,
					 substream->pcm->name, size);
				return;
			}
			substream->buffer_bytes_max = size;
		} else {
			substream->buffer_bytes_max = UINT_MAX;
		}
		if (substream->dma_buffer.area)
			do_free_pages(card, &substream->dma_buffer);
		substream->dma_buffer = new_dmab;
	} else {
		buffer->error = -EINVAL;
	}
}

static inline void preallocate_info_init(struct snd_pcm_substream *substream)
{
	struct snd_info_entry *entry;

	entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
					   substream->proc_root);
	if (entry) {
		snd_info_set_text_ops(entry, substream,
				      snd_pcm_lib_preallocate_proc_read);
		entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
		entry->mode |= 0200;
	}
	entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
					   substream->proc_root);
	if (entry)
		snd_info_set_text_ops(entry, substream,
				      snd_pcm_lib_preallocate_max_proc_read);
}

#else /* !CONFIG_SND_VERBOSE_PROCFS */
static inline void preallocate_info_init(struct snd_pcm_substream *substream)
{
}
#endif /* CONFIG_SND_VERBOSE_PROCFS */

/*
 * pre-allocate the buffer and create a proc file for the substream
 */
static int preallocate_pages(struct snd_pcm_substream *substream,
			      int type, struct device *data,
			      size_t size, size_t max, bool managed)
{
	int err;

	if (snd_BUG_ON(substream->dma_buffer.dev.type))
		return -EINVAL;

	substream->dma_buffer.dev.type = type;
	substream->dma_buffer.dev.dev = data;

	if (size > 0) {
		if (!max) {
			/* no fallback, only also inform -ENOMEM */
			err = preallocate_pcm_pages(substream, size, true);
			if (err < 0)
				return err;
		} else if (preallocate_dma &&
			   substream->number < maximum_substreams) {
			err = preallocate_pcm_pages(substream, size, false);
			if (err < 0 && err != -ENOMEM)
				return err;
		}
	}

	if (substream->dma_buffer.bytes > 0)
		substream->buffer_bytes_max = substream->dma_buffer.bytes;
	substream->dma_max = max;
	if (max > 0)
		preallocate_info_init(substream);
	if (managed)
		substream->managed_buffer_alloc = 1;
	return 0;
}

static int preallocate_pages_for_all(struct snd_pcm *pcm, int type,
				      void *data, size_t size, size_t max,
				      bool managed)
{
	struct snd_pcm_substream *substream;
	int stream, err;

	for_each_pcm_substream(pcm, stream, substream) {
		err = preallocate_pages(substream, type, data, size, max, managed);
		if (err < 0)
			return err;
	}
	return 0;
}

/**
 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
 * @substream: the pcm substream instance
 * @type: DMA type (SNDRV_DMA_TYPE_*)
 * @data: DMA type dependent data
 * @size: the requested pre-allocation size in bytes
 * @max: the max. allowed pre-allocation size
 *
 * Do pre-allocation for the given DMA buffer type.
 */
void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
				  int type, struct device *data,
				  size_t size, size_t max)
{
	preallocate_pages(substream, type, data, size, max, false);
}
EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);

/**
 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
 * @pcm: the pcm instance
 * @type: DMA type (SNDRV_DMA_TYPE_*)
 * @data: DMA type dependent data
 * @size: the requested pre-allocation size in bytes
 * @max: the max. allowed pre-allocation size
 *
 * Do pre-allocation to all substreams of the given pcm for the
 * specified DMA type.
 */
void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
					  int type, void *data,
					  size_t size, size_t max)
{
	preallocate_pages_for_all(pcm, type, data, size, max, false);
}
EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);

/**
 * snd_pcm_set_managed_buffer - set up buffer management for a substream
 * @substream: the pcm substream instance
 * @type: DMA type (SNDRV_DMA_TYPE_*)
 * @data: DMA type dependent data
 * @size: the requested pre-allocation size in bytes
 * @max: the max. allowed pre-allocation size
 *
 * Do pre-allocation for the given DMA buffer type, and set the managed
 * buffer allocation mode to the given substream.
 * In this mode, PCM core will allocate a buffer automatically before PCM
 * hw_params ops call, and release the buffer after PCM hw_free ops call
 * as well, so that the driver doesn't need to invoke the allocation and
 * the release explicitly in its callback.
 * When a buffer is actually allocated before the PCM hw_params call, it
 * turns on the runtime buffer_changed flag for drivers changing their h/w
 * parameters accordingly.
 *
 * When @size is non-zero and @max is zero, this tries to allocate for only
 * the exact buffer size without fallback, and may return -ENOMEM.
 * Otherwise, the function tries to allocate smaller chunks if the allocation
 * fails.  This is the behavior of snd_pcm_set_fixed_buffer().
 *
 * When both @size and @max are zero, the function only sets up the buffer
 * for later dynamic allocations. It's used typically for buffers with
 * SNDRV_DMA_TYPE_VMALLOC type.
 *
 * Upon successful buffer allocation and setup, the function returns 0.
 *
 * Return: zero if successful, or a negative error code
 */
int snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type,
				struct device *data, size_t size, size_t max)
{
	return preallocate_pages(substream, type, data, size, max, true);
}
EXPORT_SYMBOL(snd_pcm_set_managed_buffer);

/**
 * snd_pcm_set_managed_buffer_all - set up buffer management for all substreams
 *	for all substreams
 * @pcm: the pcm instance
 * @type: DMA type (SNDRV_DMA_TYPE_*)
 * @data: DMA type dependent data
 * @size: the requested pre-allocation size in bytes
 * @max: the max. allowed pre-allocation size
 *
 * Do pre-allocation to all substreams of the given pcm for the specified DMA
 * type and size, and set the managed_buffer_alloc flag to each substream.
 *
 * Return: zero if successful, or a negative error code
 */
int snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type,
				   struct device *data,
				   size_t size, size_t max)
{
	return preallocate_pages_for_all(pcm, type, data, size, max, true);
}
EXPORT_SYMBOL(snd_pcm_set_managed_buffer_all);

/**
 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
 * @substream: the substream to allocate the DMA buffer to
 * @size: the requested buffer size in bytes
 *
 * Allocates the DMA buffer on the BUS type given earlier to
 * snd_pcm_lib_preallocate_xxx_pages().
 *
 * Return: 1 if the buffer is changed, 0 if not changed, or a negative
 * code on failure.
 */
int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
{
	struct snd_card *card;
	struct snd_pcm_runtime *runtime;
	struct snd_dma_buffer *dmab = NULL;

	if (PCM_RUNTIME_CHECK(substream))
		return -EINVAL;
	if (snd_BUG_ON(substream->dma_buffer.dev.type ==
		       SNDRV_DMA_TYPE_UNKNOWN))
		return -EINVAL;
	runtime = substream->runtime;
	card = substream->pcm->card;

	if (runtime->dma_buffer_p) {
		/* perphaps, we might free the large DMA memory region
		   to save some space here, but the actual solution
		   costs us less time */
		if (runtime->dma_buffer_p->bytes >= size) {
			runtime->dma_bytes = size;
			return 0;	/* ok, do not change */
		}
		snd_pcm_lib_free_pages(substream);
	}
	if (substream->dma_buffer.area != NULL &&
	    substream->dma_buffer.bytes >= size) {
		dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
	} else {
		/* dma_max=0 means the fixed size preallocation */
		if (substream->dma_buffer.area && !substream->dma_max)
			return -ENOMEM;
		dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
		if (! dmab)
			return -ENOMEM;
		dmab->dev = substream->dma_buffer.dev;
		if (do_alloc_pages(card,
				   substream->dma_buffer.dev.type,
				   substream->dma_buffer.dev.dev,
				   substream->stream,
				   size, dmab) < 0) {
			kfree(dmab);
			pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
				 substream->pcm->card->number, substream->pcm->device,
				 substream->stream ? 'c' : 'p', substream->number,
				 substream->pcm->name, size);
			return -ENOMEM;
		}
	}
	snd_pcm_set_runtime_buffer(substream, dmab);
	runtime->dma_bytes = size;
	return 1;			/* area was changed */
}
EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);

/**
 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
 * @substream: the substream to release the DMA buffer
 *
 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime;

	if (PCM_RUNTIME_CHECK(substream))
		return -EINVAL;
	runtime = substream->runtime;
	if (runtime->dma_area == NULL)
		return 0;
	if (runtime->dma_buffer_p != &substream->dma_buffer) {
		struct snd_card *card = substream->pcm->card;

		/* it's a newly allocated buffer.  release it now. */
		do_free_pages(card, runtime->dma_buffer_p);
		kfree(runtime->dma_buffer_p);
	}
	snd_pcm_set_runtime_buffer(substream, NULL);
	return 0;
}
EXPORT_SYMBOL(snd_pcm_lib_free_pages);