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1/*
2 * Digital Audio (PCM) abstract layer
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 *
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22#include <asm/io.h>
23#include <linux/time.h>
24#include <linux/init.h>
25#include <linux/slab.h>
26#include <linux/moduleparam.h>
27#include <linux/vmalloc.h>
28#include <linux/export.h>
29#include <sound/core.h>
30#include <sound/pcm.h>
31#include <sound/info.h>
32#include <sound/initval.h>
33
34static int preallocate_dma = 1;
35module_param(preallocate_dma, int, 0444);
36MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
37
38static int maximum_substreams = 4;
39module_param(maximum_substreams, int, 0444);
40MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
41
42static const size_t snd_minimum_buffer = 16384;
43
44
45/*
46 * try to allocate as the large pages as possible.
47 * stores the resultant memory size in *res_size.
48 *
49 * the minimum size is snd_minimum_buffer. it should be power of 2.
50 */
51static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
52{
53 struct snd_dma_buffer *dmab = &substream->dma_buffer;
54 size_t orig_size = size;
55 int err;
56
57 do {
58 if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
59 size, dmab)) < 0) {
60 if (err != -ENOMEM)
61 return err; /* fatal error */
62 } else
63 return 0;
64 size >>= 1;
65 } while (size >= snd_minimum_buffer);
66 dmab->bytes = 0; /* tell error */
67 pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
68 substream->pcm->card->number, substream->pcm->device,
69 substream->stream ? 'c' : 'p', substream->number,
70 substream->pcm->name, orig_size);
71 return 0;
72}
73
74/*
75 * release the preallocated buffer if not yet done.
76 */
77static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
78{
79 if (substream->dma_buffer.area == NULL)
80 return;
81 snd_dma_free_pages(&substream->dma_buffer);
82 substream->dma_buffer.area = NULL;
83}
84
85/**
86 * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
87 * @substream: the pcm substream instance
88 *
89 * Releases the pre-allocated buffer of the given substream.
90 *
91 * Return: Zero if successful, or a negative error code on failure.
92 */
93int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
94{
95 snd_pcm_lib_preallocate_dma_free(substream);
96#ifdef CONFIG_SND_VERBOSE_PROCFS
97 snd_info_free_entry(substream->proc_prealloc_max_entry);
98 substream->proc_prealloc_max_entry = NULL;
99 snd_info_free_entry(substream->proc_prealloc_entry);
100 substream->proc_prealloc_entry = NULL;
101#endif
102 return 0;
103}
104
105/**
106 * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
107 * @pcm: the pcm instance
108 *
109 * Releases all the pre-allocated buffers on the given pcm.
110 *
111 * Return: Zero if successful, or a negative error code on failure.
112 */
113int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
114{
115 struct snd_pcm_substream *substream;
116 int stream;
117
118 for (stream = 0; stream < 2; stream++)
119 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
120 snd_pcm_lib_preallocate_free(substream);
121 return 0;
122}
123
124EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
125
126#ifdef CONFIG_SND_VERBOSE_PROCFS
127/*
128 * read callback for prealloc proc file
129 *
130 * prints the current allocated size in kB.
131 */
132static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
133 struct snd_info_buffer *buffer)
134{
135 struct snd_pcm_substream *substream = entry->private_data;
136 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
137}
138
139/*
140 * read callback for prealloc_max proc file
141 *
142 * prints the maximum allowed size in kB.
143 */
144static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
145 struct snd_info_buffer *buffer)
146{
147 struct snd_pcm_substream *substream = entry->private_data;
148 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
149}
150
151/*
152 * write callback for prealloc proc file
153 *
154 * accepts the preallocation size in kB.
155 */
156static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
157 struct snd_info_buffer *buffer)
158{
159 struct snd_pcm_substream *substream = entry->private_data;
160 char line[64], str[64];
161 size_t size;
162 struct snd_dma_buffer new_dmab;
163
164 if (substream->runtime) {
165 buffer->error = -EBUSY;
166 return;
167 }
168 if (!snd_info_get_line(buffer, line, sizeof(line))) {
169 snd_info_get_str(str, line, sizeof(str));
170 size = simple_strtoul(str, NULL, 10) * 1024;
171 if ((size != 0 && size < 8192) || size > substream->dma_max) {
172 buffer->error = -EINVAL;
173 return;
174 }
175 if (substream->dma_buffer.bytes == size)
176 return;
177 memset(&new_dmab, 0, sizeof(new_dmab));
178 new_dmab.dev = substream->dma_buffer.dev;
179 if (size > 0) {
180 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
181 substream->dma_buffer.dev.dev,
182 size, &new_dmab) < 0) {
183 buffer->error = -ENOMEM;
184 return;
185 }
186 substream->buffer_bytes_max = size;
187 } else {
188 substream->buffer_bytes_max = UINT_MAX;
189 }
190 if (substream->dma_buffer.area)
191 snd_dma_free_pages(&substream->dma_buffer);
192 substream->dma_buffer = new_dmab;
193 } else {
194 buffer->error = -EINVAL;
195 }
196}
197
198static inline void preallocate_info_init(struct snd_pcm_substream *substream)
199{
200 struct snd_info_entry *entry;
201
202 if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
203 entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
204 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
205 entry->mode |= S_IWUSR;
206 entry->private_data = substream;
207 if (snd_info_register(entry) < 0) {
208 snd_info_free_entry(entry);
209 entry = NULL;
210 }
211 }
212 substream->proc_prealloc_entry = entry;
213 if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
214 entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
215 entry->private_data = substream;
216 if (snd_info_register(entry) < 0) {
217 snd_info_free_entry(entry);
218 entry = NULL;
219 }
220 }
221 substream->proc_prealloc_max_entry = entry;
222}
223
224#else /* !CONFIG_SND_VERBOSE_PROCFS */
225#define preallocate_info_init(s)
226#endif /* CONFIG_SND_VERBOSE_PROCFS */
227
228/*
229 * pre-allocate the buffer and create a proc file for the substream
230 */
231static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
232 size_t size, size_t max)
233{
234
235 if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
236 preallocate_pcm_pages(substream, size);
237
238 if (substream->dma_buffer.bytes > 0)
239 substream->buffer_bytes_max = substream->dma_buffer.bytes;
240 substream->dma_max = max;
241 preallocate_info_init(substream);
242 return 0;
243}
244
245
246/**
247 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
248 * @substream: the pcm substream instance
249 * @type: DMA type (SNDRV_DMA_TYPE_*)
250 * @data: DMA type dependent data
251 * @size: the requested pre-allocation size in bytes
252 * @max: the max. allowed pre-allocation size
253 *
254 * Do pre-allocation for the given DMA buffer type.
255 *
256 * Return: Zero if successful, or a negative error code on failure.
257 */
258int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
259 int type, struct device *data,
260 size_t size, size_t max)
261{
262 substream->dma_buffer.dev.type = type;
263 substream->dma_buffer.dev.dev = data;
264 return snd_pcm_lib_preallocate_pages1(substream, size, max);
265}
266
267EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
268
269/**
270 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
271 * @pcm: the pcm instance
272 * @type: DMA type (SNDRV_DMA_TYPE_*)
273 * @data: DMA type dependent data
274 * @size: the requested pre-allocation size in bytes
275 * @max: the max. allowed pre-allocation size
276 *
277 * Do pre-allocation to all substreams of the given pcm for the
278 * specified DMA type.
279 *
280 * Return: Zero if successful, or a negative error code on failure.
281 */
282int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
283 int type, void *data,
284 size_t size, size_t max)
285{
286 struct snd_pcm_substream *substream;
287 int stream, err;
288
289 for (stream = 0; stream < 2; stream++)
290 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
291 if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
292 return err;
293 return 0;
294}
295
296EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
297
298#ifdef CONFIG_SND_DMA_SGBUF
299/**
300 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
301 * @substream: the pcm substream instance
302 * @offset: the buffer offset
303 *
304 * Used as the page callback of PCM ops.
305 *
306 * Return: The page struct at the given buffer offset. %NULL on failure.
307 */
308struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
309{
310 struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
311
312 unsigned int idx = offset >> PAGE_SHIFT;
313 if (idx >= (unsigned int)sgbuf->pages)
314 return NULL;
315 return sgbuf->page_table[idx];
316}
317
318EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
319#endif /* CONFIG_SND_DMA_SGBUF */
320
321/**
322 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
323 * @substream: the substream to allocate the DMA buffer to
324 * @size: the requested buffer size in bytes
325 *
326 * Allocates the DMA buffer on the BUS type given earlier to
327 * snd_pcm_lib_preallocate_xxx_pages().
328 *
329 * Return: 1 if the buffer is changed, 0 if not changed, or a negative
330 * code on failure.
331 */
332int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
333{
334 struct snd_pcm_runtime *runtime;
335 struct snd_dma_buffer *dmab = NULL;
336
337 if (PCM_RUNTIME_CHECK(substream))
338 return -EINVAL;
339 if (snd_BUG_ON(substream->dma_buffer.dev.type ==
340 SNDRV_DMA_TYPE_UNKNOWN))
341 return -EINVAL;
342 runtime = substream->runtime;
343
344 if (runtime->dma_buffer_p) {
345 /* perphaps, we might free the large DMA memory region
346 to save some space here, but the actual solution
347 costs us less time */
348 if (runtime->dma_buffer_p->bytes >= size) {
349 runtime->dma_bytes = size;
350 return 0; /* ok, do not change */
351 }
352 snd_pcm_lib_free_pages(substream);
353 }
354 if (substream->dma_buffer.area != NULL &&
355 substream->dma_buffer.bytes >= size) {
356 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
357 } else {
358 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
359 if (! dmab)
360 return -ENOMEM;
361 dmab->dev = substream->dma_buffer.dev;
362 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
363 substream->dma_buffer.dev.dev,
364 size, dmab) < 0) {
365 kfree(dmab);
366 return -ENOMEM;
367 }
368 }
369 snd_pcm_set_runtime_buffer(substream, dmab);
370 runtime->dma_bytes = size;
371 return 1; /* area was changed */
372}
373
374EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
375
376/**
377 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
378 * @substream: the substream to release the DMA buffer
379 *
380 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
381 *
382 * Return: Zero if successful, or a negative error code on failure.
383 */
384int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
385{
386 struct snd_pcm_runtime *runtime;
387
388 if (PCM_RUNTIME_CHECK(substream))
389 return -EINVAL;
390 runtime = substream->runtime;
391 if (runtime->dma_area == NULL)
392 return 0;
393 if (runtime->dma_buffer_p != &substream->dma_buffer) {
394 /* it's a newly allocated buffer. release it now. */
395 snd_dma_free_pages(runtime->dma_buffer_p);
396 kfree(runtime->dma_buffer_p);
397 }
398 snd_pcm_set_runtime_buffer(substream, NULL);
399 return 0;
400}
401
402EXPORT_SYMBOL(snd_pcm_lib_free_pages);
403
404int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
405 size_t size, gfp_t gfp_flags)
406{
407 struct snd_pcm_runtime *runtime;
408
409 if (PCM_RUNTIME_CHECK(substream))
410 return -EINVAL;
411 runtime = substream->runtime;
412 if (runtime->dma_area) {
413 if (runtime->dma_bytes >= size)
414 return 0; /* already large enough */
415 vfree(runtime->dma_area);
416 }
417 runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
418 if (!runtime->dma_area)
419 return -ENOMEM;
420 runtime->dma_bytes = size;
421 return 1;
422}
423EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
424
425/**
426 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
427 * @substream: the substream with a buffer allocated by
428 * snd_pcm_lib_alloc_vmalloc_buffer()
429 *
430 * Return: Zero if successful, or a negative error code on failure.
431 */
432int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
433{
434 struct snd_pcm_runtime *runtime;
435
436 if (PCM_RUNTIME_CHECK(substream))
437 return -EINVAL;
438 runtime = substream->runtime;
439 vfree(runtime->dma_area);
440 runtime->dma_area = NULL;
441 return 0;
442}
443EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
444
445/**
446 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
447 * @substream: the substream with a buffer allocated by
448 * snd_pcm_lib_alloc_vmalloc_buffer()
449 * @offset: offset in the buffer
450 *
451 * This function is to be used as the page callback in the PCM ops.
452 *
453 * Return: The page struct, or %NULL on failure.
454 */
455struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
456 unsigned long offset)
457{
458 return vmalloc_to_page(substream->runtime->dma_area + offset);
459}
460EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Digital Audio (PCM) abstract layer
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/io.h>
8#include <linux/time.h>
9#include <linux/init.h>
10#include <linux/slab.h>
11#include <linux/moduleparam.h>
12#include <linux/export.h>
13#include <sound/core.h>
14#include <sound/pcm.h>
15#include <sound/info.h>
16#include <sound/initval.h>
17#include "pcm_local.h"
18
19static int preallocate_dma = 1;
20module_param(preallocate_dma, int, 0444);
21MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
22
23static int maximum_substreams = 4;
24module_param(maximum_substreams, int, 0444);
25MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
26
27static const size_t snd_minimum_buffer = 16384;
28
29static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL;
30module_param(max_alloc_per_card, ulong, 0644);
31MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card.");
32
33static void __update_allocated_size(struct snd_card *card, ssize_t bytes)
34{
35 card->total_pcm_alloc_bytes += bytes;
36}
37
38static void update_allocated_size(struct snd_card *card, ssize_t bytes)
39{
40 guard(mutex)(&card->memory_mutex);
41 __update_allocated_size(card, bytes);
42}
43
44static void decrease_allocated_size(struct snd_card *card, size_t bytes)
45{
46 guard(mutex)(&card->memory_mutex);
47 WARN_ON(card->total_pcm_alloc_bytes < bytes);
48 __update_allocated_size(card, -(ssize_t)bytes);
49}
50
51static int do_alloc_pages(struct snd_card *card, int type, struct device *dev,
52 int str, size_t size, struct snd_dma_buffer *dmab)
53{
54 enum dma_data_direction dir;
55 int err;
56
57 /* check and reserve the requested size */
58 scoped_guard(mutex, &card->memory_mutex) {
59 if (max_alloc_per_card &&
60 card->total_pcm_alloc_bytes + size > max_alloc_per_card)
61 return -ENOMEM;
62 __update_allocated_size(card, size);
63 }
64
65 if (str == SNDRV_PCM_STREAM_PLAYBACK)
66 dir = DMA_TO_DEVICE;
67 else
68 dir = DMA_FROM_DEVICE;
69 err = snd_dma_alloc_dir_pages(type, dev, dir, size, dmab);
70 if (!err) {
71 /* the actual allocation size might be bigger than requested,
72 * and we need to correct the account
73 */
74 if (dmab->bytes != size)
75 update_allocated_size(card, dmab->bytes - size);
76 } else {
77 /* take back on allocation failure */
78 decrease_allocated_size(card, size);
79 }
80 return err;
81}
82
83static void do_free_pages(struct snd_card *card, struct snd_dma_buffer *dmab)
84{
85 if (!dmab->area)
86 return;
87 decrease_allocated_size(card, dmab->bytes);
88 snd_dma_free_pages(dmab);
89 dmab->area = NULL;
90}
91
92/*
93 * try to allocate as the large pages as possible.
94 * stores the resultant memory size in *res_size.
95 *
96 * the minimum size is snd_minimum_buffer. it should be power of 2.
97 */
98static int preallocate_pcm_pages(struct snd_pcm_substream *substream,
99 size_t size, bool no_fallback)
100{
101 struct snd_dma_buffer *dmab = &substream->dma_buffer;
102 struct snd_card *card = substream->pcm->card;
103 size_t orig_size = size;
104 int err;
105
106 do {
107 err = do_alloc_pages(card, dmab->dev.type, dmab->dev.dev,
108 substream->stream, size, dmab);
109 if (err != -ENOMEM)
110 return err;
111 if (no_fallback)
112 break;
113 size >>= 1;
114 } while (size >= snd_minimum_buffer);
115 dmab->bytes = 0; /* tell error */
116 pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
117 substream->pcm->card->number, substream->pcm->device,
118 substream->stream ? 'c' : 'p', substream->number,
119 substream->pcm->name, orig_size);
120 return -ENOMEM;
121}
122
123/**
124 * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
125 * @substream: the pcm substream instance
126 *
127 * Releases the pre-allocated buffer of the given substream.
128 */
129void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
130{
131 do_free_pages(substream->pcm->card, &substream->dma_buffer);
132}
133
134/**
135 * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
136 * @pcm: the pcm instance
137 *
138 * Releases all the pre-allocated buffers on the given pcm.
139 */
140void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
141{
142 struct snd_pcm_substream *substream;
143 int stream;
144
145 for_each_pcm_substream(pcm, stream, substream)
146 snd_pcm_lib_preallocate_free(substream);
147}
148EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
149
150#ifdef CONFIG_SND_VERBOSE_PROCFS
151/*
152 * read callback for prealloc proc file
153 *
154 * prints the current allocated size in kB.
155 */
156static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
157 struct snd_info_buffer *buffer)
158{
159 struct snd_pcm_substream *substream = entry->private_data;
160 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
161}
162
163/*
164 * read callback for prealloc_max proc file
165 *
166 * prints the maximum allowed size in kB.
167 */
168static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
169 struct snd_info_buffer *buffer)
170{
171 struct snd_pcm_substream *substream = entry->private_data;
172 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
173}
174
175/*
176 * write callback for prealloc proc file
177 *
178 * accepts the preallocation size in kB.
179 */
180static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
181 struct snd_info_buffer *buffer)
182{
183 struct snd_pcm_substream *substream = entry->private_data;
184 struct snd_card *card = substream->pcm->card;
185 char line[64], str[64];
186 unsigned long size;
187 struct snd_dma_buffer new_dmab;
188
189 guard(mutex)(&substream->pcm->open_mutex);
190 if (substream->runtime) {
191 buffer->error = -EBUSY;
192 return;
193 }
194 if (!snd_info_get_line(buffer, line, sizeof(line))) {
195 snd_info_get_str(str, line, sizeof(str));
196 buffer->error = kstrtoul(str, 10, &size);
197 if (buffer->error != 0)
198 return;
199 size *= 1024;
200 if ((size != 0 && size < 8192) || size > substream->dma_max) {
201 buffer->error = -EINVAL;
202 return;
203 }
204 if (substream->dma_buffer.bytes == size)
205 return;
206 memset(&new_dmab, 0, sizeof(new_dmab));
207 new_dmab.dev = substream->dma_buffer.dev;
208 if (size > 0) {
209 if (do_alloc_pages(card,
210 substream->dma_buffer.dev.type,
211 substream->dma_buffer.dev.dev,
212 substream->stream,
213 size, &new_dmab) < 0) {
214 buffer->error = -ENOMEM;
215 pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %lu\n",
216 substream->pcm->card->number, substream->pcm->device,
217 substream->stream ? 'c' : 'p', substream->number,
218 substream->pcm->name, size);
219 return;
220 }
221 substream->buffer_bytes_max = size;
222 } else {
223 substream->buffer_bytes_max = UINT_MAX;
224 }
225 if (substream->dma_buffer.area)
226 do_free_pages(card, &substream->dma_buffer);
227 substream->dma_buffer = new_dmab;
228 } else {
229 buffer->error = -EINVAL;
230 }
231}
232
233static inline void preallocate_info_init(struct snd_pcm_substream *substream)
234{
235 struct snd_info_entry *entry;
236
237 entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
238 substream->proc_root);
239 if (entry) {
240 snd_info_set_text_ops(entry, substream,
241 snd_pcm_lib_preallocate_proc_read);
242 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
243 entry->mode |= 0200;
244 }
245 entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
246 substream->proc_root);
247 if (entry)
248 snd_info_set_text_ops(entry, substream,
249 snd_pcm_lib_preallocate_max_proc_read);
250}
251
252#else /* !CONFIG_SND_VERBOSE_PROCFS */
253static inline void preallocate_info_init(struct snd_pcm_substream *substream)
254{
255}
256#endif /* CONFIG_SND_VERBOSE_PROCFS */
257
258/*
259 * pre-allocate the buffer and create a proc file for the substream
260 */
261static int preallocate_pages(struct snd_pcm_substream *substream,
262 int type, struct device *data,
263 size_t size, size_t max, bool managed)
264{
265 int err;
266
267 if (snd_BUG_ON(substream->dma_buffer.dev.type))
268 return -EINVAL;
269
270 substream->dma_buffer.dev.type = type;
271 substream->dma_buffer.dev.dev = data;
272
273 if (size > 0) {
274 if (!max) {
275 /* no fallback, only also inform -ENOMEM */
276 err = preallocate_pcm_pages(substream, size, true);
277 if (err < 0)
278 return err;
279 } else if (preallocate_dma &&
280 substream->number < maximum_substreams) {
281 err = preallocate_pcm_pages(substream, size, false);
282 if (err < 0 && err != -ENOMEM)
283 return err;
284 }
285 }
286
287 if (substream->dma_buffer.bytes > 0)
288 substream->buffer_bytes_max = substream->dma_buffer.bytes;
289 substream->dma_max = max;
290 if (max > 0)
291 preallocate_info_init(substream);
292 if (managed)
293 substream->managed_buffer_alloc = 1;
294 return 0;
295}
296
297static int preallocate_pages_for_all(struct snd_pcm *pcm, int type,
298 void *data, size_t size, size_t max,
299 bool managed)
300{
301 struct snd_pcm_substream *substream;
302 int stream, err;
303
304 for_each_pcm_substream(pcm, stream, substream) {
305 err = preallocate_pages(substream, type, data, size, max, managed);
306 if (err < 0)
307 return err;
308 }
309 return 0;
310}
311
312/**
313 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
314 * @substream: the pcm substream instance
315 * @type: DMA type (SNDRV_DMA_TYPE_*)
316 * @data: DMA type dependent data
317 * @size: the requested pre-allocation size in bytes
318 * @max: the max. allowed pre-allocation size
319 *
320 * Do pre-allocation for the given DMA buffer type.
321 */
322void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
323 int type, struct device *data,
324 size_t size, size_t max)
325{
326 preallocate_pages(substream, type, data, size, max, false);
327}
328EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
329
330/**
331 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
332 * @pcm: the pcm instance
333 * @type: DMA type (SNDRV_DMA_TYPE_*)
334 * @data: DMA type dependent data
335 * @size: the requested pre-allocation size in bytes
336 * @max: the max. allowed pre-allocation size
337 *
338 * Do pre-allocation to all substreams of the given pcm for the
339 * specified DMA type.
340 */
341void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
342 int type, void *data,
343 size_t size, size_t max)
344{
345 preallocate_pages_for_all(pcm, type, data, size, max, false);
346}
347EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
348
349/**
350 * snd_pcm_set_managed_buffer - set up buffer management for a substream
351 * @substream: the pcm substream instance
352 * @type: DMA type (SNDRV_DMA_TYPE_*)
353 * @data: DMA type dependent data
354 * @size: the requested pre-allocation size in bytes
355 * @max: the max. allowed pre-allocation size
356 *
357 * Do pre-allocation for the given DMA buffer type, and set the managed
358 * buffer allocation mode to the given substream.
359 * In this mode, PCM core will allocate a buffer automatically before PCM
360 * hw_params ops call, and release the buffer after PCM hw_free ops call
361 * as well, so that the driver doesn't need to invoke the allocation and
362 * the release explicitly in its callback.
363 * When a buffer is actually allocated before the PCM hw_params call, it
364 * turns on the runtime buffer_changed flag for drivers changing their h/w
365 * parameters accordingly.
366 *
367 * When @size is non-zero and @max is zero, this tries to allocate for only
368 * the exact buffer size without fallback, and may return -ENOMEM.
369 * Otherwise, the function tries to allocate smaller chunks if the allocation
370 * fails. This is the behavior of snd_pcm_set_fixed_buffer().
371 *
372 * When both @size and @max are zero, the function only sets up the buffer
373 * for later dynamic allocations. It's used typically for buffers with
374 * SNDRV_DMA_TYPE_VMALLOC type.
375 *
376 * Upon successful buffer allocation and setup, the function returns 0.
377 *
378 * Return: zero if successful, or a negative error code
379 */
380int snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type,
381 struct device *data, size_t size, size_t max)
382{
383 return preallocate_pages(substream, type, data, size, max, true);
384}
385EXPORT_SYMBOL(snd_pcm_set_managed_buffer);
386
387/**
388 * snd_pcm_set_managed_buffer_all - set up buffer management for all substreams
389 * for all substreams
390 * @pcm: the pcm instance
391 * @type: DMA type (SNDRV_DMA_TYPE_*)
392 * @data: DMA type dependent data
393 * @size: the requested pre-allocation size in bytes
394 * @max: the max. allowed pre-allocation size
395 *
396 * Do pre-allocation to all substreams of the given pcm for the specified DMA
397 * type and size, and set the managed_buffer_alloc flag to each substream.
398 *
399 * Return: zero if successful, or a negative error code
400 */
401int snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type,
402 struct device *data,
403 size_t size, size_t max)
404{
405 return preallocate_pages_for_all(pcm, type, data, size, max, true);
406}
407EXPORT_SYMBOL(snd_pcm_set_managed_buffer_all);
408
409/**
410 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
411 * @substream: the substream to allocate the DMA buffer to
412 * @size: the requested buffer size in bytes
413 *
414 * Allocates the DMA buffer on the BUS type given earlier to
415 * snd_pcm_lib_preallocate_xxx_pages().
416 *
417 * Return: 1 if the buffer is changed, 0 if not changed, or a negative
418 * code on failure.
419 */
420int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
421{
422 struct snd_card *card;
423 struct snd_pcm_runtime *runtime;
424 struct snd_dma_buffer *dmab = NULL;
425
426 if (PCM_RUNTIME_CHECK(substream))
427 return -EINVAL;
428 if (snd_BUG_ON(substream->dma_buffer.dev.type ==
429 SNDRV_DMA_TYPE_UNKNOWN))
430 return -EINVAL;
431 runtime = substream->runtime;
432 card = substream->pcm->card;
433
434 if (runtime->dma_buffer_p) {
435 /* perphaps, we might free the large DMA memory region
436 to save some space here, but the actual solution
437 costs us less time */
438 if (runtime->dma_buffer_p->bytes >= size) {
439 runtime->dma_bytes = size;
440 return 0; /* ok, do not change */
441 }
442 snd_pcm_lib_free_pages(substream);
443 }
444 if (substream->dma_buffer.area != NULL &&
445 substream->dma_buffer.bytes >= size) {
446 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
447 } else {
448 /* dma_max=0 means the fixed size preallocation */
449 if (substream->dma_buffer.area && !substream->dma_max)
450 return -ENOMEM;
451 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
452 if (! dmab)
453 return -ENOMEM;
454 dmab->dev = substream->dma_buffer.dev;
455 if (do_alloc_pages(card,
456 substream->dma_buffer.dev.type,
457 substream->dma_buffer.dev.dev,
458 substream->stream,
459 size, dmab) < 0) {
460 kfree(dmab);
461 pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
462 substream->pcm->card->number, substream->pcm->device,
463 substream->stream ? 'c' : 'p', substream->number,
464 substream->pcm->name, size);
465 return -ENOMEM;
466 }
467 }
468 snd_pcm_set_runtime_buffer(substream, dmab);
469 runtime->dma_bytes = size;
470 return 1; /* area was changed */
471}
472EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
473
474/**
475 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
476 * @substream: the substream to release the DMA buffer
477 *
478 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
479 *
480 * Return: Zero if successful, or a negative error code on failure.
481 */
482int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
483{
484 struct snd_pcm_runtime *runtime;
485
486 if (PCM_RUNTIME_CHECK(substream))
487 return -EINVAL;
488 runtime = substream->runtime;
489 if (runtime->dma_area == NULL)
490 return 0;
491 if (runtime->dma_buffer_p != &substream->dma_buffer) {
492 struct snd_card *card = substream->pcm->card;
493
494 /* it's a newly allocated buffer. release it now. */
495 do_free_pages(card, runtime->dma_buffer_p);
496 kfree(runtime->dma_buffer_p);
497 }
498 snd_pcm_set_runtime_buffer(substream, NULL);
499 return 0;
500}
501EXPORT_SYMBOL(snd_pcm_lib_free_pages);