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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/*
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);