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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 <linux/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}
123EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
124
125#ifdef CONFIG_SND_VERBOSE_PROCFS
126/*
127 * read callback for prealloc proc file
128 *
129 * prints the current allocated size in kB.
130 */
131static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
132 struct snd_info_buffer *buffer)
133{
134 struct snd_pcm_substream *substream = entry->private_data;
135 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
136}
137
138/*
139 * read callback for prealloc_max proc file
140 *
141 * prints the maximum allowed size in kB.
142 */
143static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
144 struct snd_info_buffer *buffer)
145{
146 struct snd_pcm_substream *substream = entry->private_data;
147 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
148}
149
150/*
151 * write callback for prealloc proc file
152 *
153 * accepts the preallocation size in kB.
154 */
155static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
156 struct snd_info_buffer *buffer)
157{
158 struct snd_pcm_substream *substream = entry->private_data;
159 char line[64], str[64];
160 size_t size;
161 struct snd_dma_buffer new_dmab;
162
163 if (substream->runtime) {
164 buffer->error = -EBUSY;
165 return;
166 }
167 if (!snd_info_get_line(buffer, line, sizeof(line))) {
168 snd_info_get_str(str, line, sizeof(str));
169 size = simple_strtoul(str, NULL, 10) * 1024;
170 if ((size != 0 && size < 8192) || size > substream->dma_max) {
171 buffer->error = -EINVAL;
172 return;
173 }
174 if (substream->dma_buffer.bytes == size)
175 return;
176 memset(&new_dmab, 0, sizeof(new_dmab));
177 new_dmab.dev = substream->dma_buffer.dev;
178 if (size > 0) {
179 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
180 substream->dma_buffer.dev.dev,
181 size, &new_dmab) < 0) {
182 buffer->error = -ENOMEM;
183 return;
184 }
185 substream->buffer_bytes_max = size;
186 } else {
187 substream->buffer_bytes_max = UINT_MAX;
188 }
189 if (substream->dma_buffer.area)
190 snd_dma_free_pages(&substream->dma_buffer);
191 substream->dma_buffer = new_dmab;
192 } else {
193 buffer->error = -EINVAL;
194 }
195}
196
197static inline void preallocate_info_init(struct snd_pcm_substream *substream)
198{
199 struct snd_info_entry *entry;
200
201 if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
202 entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
203 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
204 entry->mode |= S_IWUSR;
205 entry->private_data = substream;
206 if (snd_info_register(entry) < 0) {
207 snd_info_free_entry(entry);
208 entry = NULL;
209 }
210 }
211 substream->proc_prealloc_entry = entry;
212 if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
213 entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
214 entry->private_data = substream;
215 if (snd_info_register(entry) < 0) {
216 snd_info_free_entry(entry);
217 entry = NULL;
218 }
219 }
220 substream->proc_prealloc_max_entry = entry;
221}
222
223#else /* !CONFIG_SND_VERBOSE_PROCFS */
224#define preallocate_info_init(s)
225#endif /* CONFIG_SND_VERBOSE_PROCFS */
226
227/*
228 * pre-allocate the buffer and create a proc file for the substream
229 */
230static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
231 size_t size, size_t max)
232{
233
234 if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
235 preallocate_pcm_pages(substream, size);
236
237 if (substream->dma_buffer.bytes > 0)
238 substream->buffer_bytes_max = substream->dma_buffer.bytes;
239 substream->dma_max = max;
240 preallocate_info_init(substream);
241 return 0;
242}
243
244
245/**
246 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
247 * @substream: the pcm substream instance
248 * @type: DMA type (SNDRV_DMA_TYPE_*)
249 * @data: DMA type dependent data
250 * @size: the requested pre-allocation size in bytes
251 * @max: the max. allowed pre-allocation size
252 *
253 * Do pre-allocation for the given DMA buffer type.
254 *
255 * Return: Zero if successful, or a negative error code on failure.
256 */
257int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
258 int type, struct device *data,
259 size_t size, size_t max)
260{
261 substream->dma_buffer.dev.type = type;
262 substream->dma_buffer.dev.dev = data;
263 return snd_pcm_lib_preallocate_pages1(substream, size, max);
264}
265EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
266
267/**
268 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
269 * @pcm: the pcm instance
270 * @type: DMA type (SNDRV_DMA_TYPE_*)
271 * @data: DMA type dependent data
272 * @size: the requested pre-allocation size in bytes
273 * @max: the max. allowed pre-allocation size
274 *
275 * Do pre-allocation to all substreams of the given pcm for the
276 * specified DMA type.
277 *
278 * Return: Zero if successful, or a negative error code on failure.
279 */
280int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
281 int type, void *data,
282 size_t size, size_t max)
283{
284 struct snd_pcm_substream *substream;
285 int stream, err;
286
287 for (stream = 0; stream < 2; stream++)
288 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
289 if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
290 return err;
291 return 0;
292}
293EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
294
295#ifdef CONFIG_SND_DMA_SGBUF
296/**
297 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
298 * @substream: the pcm substream instance
299 * @offset: the buffer offset
300 *
301 * Used as the page callback of PCM ops.
302 *
303 * Return: The page struct at the given buffer offset. %NULL on failure.
304 */
305struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
306{
307 struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
308
309 unsigned int idx = offset >> PAGE_SHIFT;
310 if (idx >= (unsigned int)sgbuf->pages)
311 return NULL;
312 return sgbuf->page_table[idx];
313}
314EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
315#endif /* CONFIG_SND_DMA_SGBUF */
316
317/**
318 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
319 * @substream: the substream to allocate the DMA buffer to
320 * @size: the requested buffer size in bytes
321 *
322 * Allocates the DMA buffer on the BUS type given earlier to
323 * snd_pcm_lib_preallocate_xxx_pages().
324 *
325 * Return: 1 if the buffer is changed, 0 if not changed, or a negative
326 * code on failure.
327 */
328int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
329{
330 struct snd_pcm_runtime *runtime;
331 struct snd_dma_buffer *dmab = NULL;
332
333 if (PCM_RUNTIME_CHECK(substream))
334 return -EINVAL;
335 if (snd_BUG_ON(substream->dma_buffer.dev.type ==
336 SNDRV_DMA_TYPE_UNKNOWN))
337 return -EINVAL;
338 runtime = substream->runtime;
339
340 if (runtime->dma_buffer_p) {
341 /* perphaps, we might free the large DMA memory region
342 to save some space here, but the actual solution
343 costs us less time */
344 if (runtime->dma_buffer_p->bytes >= size) {
345 runtime->dma_bytes = size;
346 return 0; /* ok, do not change */
347 }
348 snd_pcm_lib_free_pages(substream);
349 }
350 if (substream->dma_buffer.area != NULL &&
351 substream->dma_buffer.bytes >= size) {
352 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
353 } else {
354 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
355 if (! dmab)
356 return -ENOMEM;
357 dmab->dev = substream->dma_buffer.dev;
358 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
359 substream->dma_buffer.dev.dev,
360 size, dmab) < 0) {
361 kfree(dmab);
362 return -ENOMEM;
363 }
364 }
365 snd_pcm_set_runtime_buffer(substream, dmab);
366 runtime->dma_bytes = size;
367 return 1; /* area was changed */
368}
369EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
370
371/**
372 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
373 * @substream: the substream to release the DMA buffer
374 *
375 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
376 *
377 * Return: Zero if successful, or a negative error code on failure.
378 */
379int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
380{
381 struct snd_pcm_runtime *runtime;
382
383 if (PCM_RUNTIME_CHECK(substream))
384 return -EINVAL;
385 runtime = substream->runtime;
386 if (runtime->dma_area == NULL)
387 return 0;
388 if (runtime->dma_buffer_p != &substream->dma_buffer) {
389 /* it's a newly allocated buffer. release it now. */
390 snd_dma_free_pages(runtime->dma_buffer_p);
391 kfree(runtime->dma_buffer_p);
392 }
393 snd_pcm_set_runtime_buffer(substream, NULL);
394 return 0;
395}
396EXPORT_SYMBOL(snd_pcm_lib_free_pages);
397
398int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
399 size_t size, gfp_t gfp_flags)
400{
401 struct snd_pcm_runtime *runtime;
402
403 if (PCM_RUNTIME_CHECK(substream))
404 return -EINVAL;
405 runtime = substream->runtime;
406 if (runtime->dma_area) {
407 if (runtime->dma_bytes >= size)
408 return 0; /* already large enough */
409 vfree(runtime->dma_area);
410 }
411 runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
412 if (!runtime->dma_area)
413 return -ENOMEM;
414 runtime->dma_bytes = size;
415 return 1;
416}
417EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
418
419/**
420 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
421 * @substream: the substream with a buffer allocated by
422 * snd_pcm_lib_alloc_vmalloc_buffer()
423 *
424 * Return: Zero if successful, or a negative error code on failure.
425 */
426int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
427{
428 struct snd_pcm_runtime *runtime;
429
430 if (PCM_RUNTIME_CHECK(substream))
431 return -EINVAL;
432 runtime = substream->runtime;
433 vfree(runtime->dma_area);
434 runtime->dma_area = NULL;
435 return 0;
436}
437EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
438
439/**
440 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
441 * @substream: the substream with a buffer allocated by
442 * snd_pcm_lib_alloc_vmalloc_buffer()
443 * @offset: offset in the buffer
444 *
445 * This function is to be used as the page callback in the PCM ops.
446 *
447 * Return: The page struct, or %NULL on failure.
448 */
449struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
450 unsigned long offset)
451{
452 return vmalloc_to_page(substream->runtime->dma_area + offset);
453}
454EXPORT_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);