Commit | Line | Data |
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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * Digital Audio (PCM) abstract layer | |
c1017a4c | 4 | * Copyright (c) by Jaroslav Kysela <perex@perex.cz> |
1da177e4 LT |
5 | */ |
6 | ||
6cbbfe1c | 7 | #include <linux/io.h> |
1da177e4 LT |
8 | #include <linux/time.h> |
9 | #include <linux/init.h> | |
5a0e3ad6 | 10 | #include <linux/slab.h> |
1da177e4 | 11 | #include <linux/moduleparam.h> |
ee7c343c | 12 | #include <linux/vmalloc.h> |
d81a6d71 | 13 | #include <linux/export.h> |
1da177e4 LT |
14 | #include <sound/core.h> |
15 | #include <sound/pcm.h> | |
16 | #include <sound/info.h> | |
17 | #include <sound/initval.h> | |
0821fd77 | 18 | #include "pcm_local.h" |
1da177e4 LT |
19 | |
20 | static int preallocate_dma = 1; | |
21 | module_param(preallocate_dma, int, 0444); | |
22 | MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized."); | |
23 | ||
24 | static int maximum_substreams = 4; | |
25 | module_param(maximum_substreams, int, 0444); | |
26 | MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory."); | |
27 | ||
28 | static const size_t snd_minimum_buffer = 16384; | |
29 | ||
d4cfb30f TI |
30 | static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL; |
31 | module_param(max_alloc_per_card, ulong, 0644); | |
32 | MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card."); | |
33 | ||
34 | static int do_alloc_pages(struct snd_card *card, int type, struct device *dev, | |
35 | size_t size, struct snd_dma_buffer *dmab) | |
36 | { | |
37 | int err; | |
38 | ||
39 | if (max_alloc_per_card && | |
40 | card->total_pcm_alloc_bytes + size > max_alloc_per_card) | |
41 | return -ENOMEM; | |
42 | err = snd_dma_alloc_pages(type, dev, size, dmab); | |
43 | if (!err) { | |
44 | mutex_lock(&card->memory_mutex); | |
45 | card->total_pcm_alloc_bytes += dmab->bytes; | |
46 | mutex_unlock(&card->memory_mutex); | |
47 | } | |
48 | return err; | |
49 | } | |
50 | ||
51 | static void do_free_pages(struct snd_card *card, struct snd_dma_buffer *dmab) | |
52 | { | |
53 | if (!dmab->area) | |
54 | return; | |
55 | mutex_lock(&card->memory_mutex); | |
56 | WARN_ON(card->total_pcm_alloc_bytes < dmab->bytes); | |
57 | card->total_pcm_alloc_bytes -= dmab->bytes; | |
58 | mutex_unlock(&card->memory_mutex); | |
59 | snd_dma_free_pages(dmab); | |
60 | dmab->area = NULL; | |
61 | } | |
1da177e4 LT |
62 | |
63 | /* | |
64 | * try to allocate as the large pages as possible. | |
65 | * stores the resultant memory size in *res_size. | |
66 | * | |
67 | * the minimum size is snd_minimum_buffer. it should be power of 2. | |
68 | */ | |
877211f5 | 69 | static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size) |
1da177e4 LT |
70 | { |
71 | struct snd_dma_buffer *dmab = &substream->dma_buffer; | |
d4cfb30f | 72 | struct snd_card *card = substream->pcm->card; |
6ab08ced | 73 | size_t orig_size = size; |
1da177e4 LT |
74 | int err; |
75 | ||
1da177e4 | 76 | do { |
d4cfb30f TI |
77 | err = do_alloc_pages(card, dmab->dev.type, dmab->dev.dev, |
78 | size, dmab); | |
79 | if (err != -ENOMEM) | |
80 | return err; | |
1da177e4 LT |
81 | size >>= 1; |
82 | } while (size >= snd_minimum_buffer); | |
83 | dmab->bytes = 0; /* tell error */ | |
6ab08ced TI |
84 | pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n", |
85 | substream->pcm->card->number, substream->pcm->device, | |
86 | substream->stream ? 'c' : 'p', substream->number, | |
87 | substream->pcm->name, orig_size); | |
1da177e4 LT |
88 | return 0; |
89 | } | |
90 | ||
91 | /* | |
92 | * release the preallocated buffer if not yet done. | |
93 | */ | |
877211f5 | 94 | static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream) |
1da177e4 | 95 | { |
d4cfb30f | 96 | do_free_pages(substream->pcm->card, &substream->dma_buffer); |
1da177e4 LT |
97 | } |
98 | ||
99 | /** | |
100 | * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream. | |
101 | * @substream: the pcm substream instance | |
102 | * | |
103 | * Releases the pre-allocated buffer of the given substream. | |
1da177e4 | 104 | */ |
bb580602 | 105 | void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream) |
1da177e4 LT |
106 | { |
107 | snd_pcm_lib_preallocate_dma_free(substream); | |
1da177e4 LT |
108 | } |
109 | ||
110 | /** | |
111 | * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm | |
112 | * @pcm: the pcm instance | |
113 | * | |
114 | * Releases all the pre-allocated buffers on the given pcm. | |
1da177e4 | 115 | */ |
bb580602 | 116 | void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm) |
1da177e4 | 117 | { |
877211f5 | 118 | struct snd_pcm_substream *substream; |
1da177e4 LT |
119 | int stream; |
120 | ||
121 | for (stream = 0; stream < 2; stream++) | |
122 | for (substream = pcm->streams[stream].substream; substream; substream = substream->next) | |
123 | snd_pcm_lib_preallocate_free(substream); | |
1da177e4 | 124 | } |
e88e8ae6 TI |
125 | EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all); |
126 | ||
b7d90a35 | 127 | #ifdef CONFIG_SND_VERBOSE_PROCFS |
1da177e4 LT |
128 | /* |
129 | * read callback for prealloc proc file | |
130 | * | |
131 | * prints the current allocated size in kB. | |
132 | */ | |
877211f5 TI |
133 | static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry, |
134 | struct snd_info_buffer *buffer) | |
1da177e4 | 135 | { |
877211f5 | 136 | struct snd_pcm_substream *substream = entry->private_data; |
1da177e4 LT |
137 | snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024); |
138 | } | |
139 | ||
c7132aeb JK |
140 | /* |
141 | * read callback for prealloc_max proc file | |
142 | * | |
143 | * prints the maximum allowed size in kB. | |
144 | */ | |
145 | static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry, | |
146 | struct snd_info_buffer *buffer) | |
147 | { | |
148 | struct snd_pcm_substream *substream = entry->private_data; | |
149 | snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024); | |
150 | } | |
151 | ||
1da177e4 LT |
152 | /* |
153 | * write callback for prealloc proc file | |
154 | * | |
155 | * accepts the preallocation size in kB. | |
156 | */ | |
877211f5 TI |
157 | static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry, |
158 | struct snd_info_buffer *buffer) | |
1da177e4 | 159 | { |
877211f5 | 160 | struct snd_pcm_substream *substream = entry->private_data; |
d4cfb30f | 161 | struct snd_card *card = substream->pcm->card; |
1da177e4 LT |
162 | char line[64], str[64]; |
163 | size_t size; | |
164 | struct snd_dma_buffer new_dmab; | |
165 | ||
166 | if (substream->runtime) { | |
167 | buffer->error = -EBUSY; | |
168 | return; | |
169 | } | |
170 | if (!snd_info_get_line(buffer, line, sizeof(line))) { | |
171 | snd_info_get_str(str, line, sizeof(str)); | |
172 | size = simple_strtoul(str, NULL, 10) * 1024; | |
173 | if ((size != 0 && size < 8192) || size > substream->dma_max) { | |
174 | buffer->error = -EINVAL; | |
175 | return; | |
176 | } | |
177 | if (substream->dma_buffer.bytes == size) | |
178 | return; | |
179 | memset(&new_dmab, 0, sizeof(new_dmab)); | |
180 | new_dmab.dev = substream->dma_buffer.dev; | |
181 | if (size > 0) { | |
d4cfb30f TI |
182 | if (do_alloc_pages(card, |
183 | substream->dma_buffer.dev.type, | |
184 | substream->dma_buffer.dev.dev, | |
185 | size, &new_dmab) < 0) { | |
1da177e4 LT |
186 | buffer->error = -ENOMEM; |
187 | return; | |
188 | } | |
189 | substream->buffer_bytes_max = size; | |
190 | } else { | |
191 | substream->buffer_bytes_max = UINT_MAX; | |
192 | } | |
193 | if (substream->dma_buffer.area) | |
d4cfb30f | 194 | do_free_pages(card, &substream->dma_buffer); |
1da177e4 LT |
195 | substream->dma_buffer = new_dmab; |
196 | } else { | |
197 | buffer->error = -EINVAL; | |
198 | } | |
199 | } | |
200 | ||
e28563cc | 201 | static inline void preallocate_info_init(struct snd_pcm_substream *substream) |
1da177e4 | 202 | { |
877211f5 | 203 | struct snd_info_entry *entry; |
1da177e4 | 204 | |
a8d14981 TI |
205 | entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", |
206 | substream->proc_root); | |
207 | if (entry) { | |
208 | snd_info_set_text_ops(entry, substream, | |
209 | snd_pcm_lib_preallocate_proc_read); | |
1da177e4 | 210 | entry->c.text.write = snd_pcm_lib_preallocate_proc_write; |
6a73cf46 | 211 | entry->mode |= 0200; |
c7132aeb | 212 | } |
a8d14981 TI |
213 | entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", |
214 | substream->proc_root); | |
215 | if (entry) | |
216 | snd_info_set_text_ops(entry, substream, | |
217 | snd_pcm_lib_preallocate_max_proc_read); | |
e28563cc TI |
218 | } |
219 | ||
b7d90a35 | 220 | #else /* !CONFIG_SND_VERBOSE_PROCFS */ |
e28563cc | 221 | #define preallocate_info_init(s) |
b7d90a35 | 222 | #endif /* CONFIG_SND_VERBOSE_PROCFS */ |
e28563cc TI |
223 | |
224 | /* | |
225 | * pre-allocate the buffer and create a proc file for the substream | |
226 | */ | |
0dba808e TI |
227 | static void preallocate_pages(struct snd_pcm_substream *substream, |
228 | int type, struct device *data, | |
229 | size_t size, size_t max, bool managed) | |
e28563cc | 230 | { |
0dba808e TI |
231 | if (snd_BUG_ON(substream->dma_buffer.dev.type)) |
232 | return; | |
233 | ||
234 | substream->dma_buffer.dev.type = type; | |
235 | substream->dma_buffer.dev.dev = data; | |
e28563cc TI |
236 | |
237 | if (size > 0 && preallocate_dma && substream->number < maximum_substreams) | |
238 | preallocate_pcm_pages(substream, size); | |
239 | ||
240 | if (substream->dma_buffer.bytes > 0) | |
241 | substream->buffer_bytes_max = substream->dma_buffer.bytes; | |
242 | substream->dma_max = max; | |
d3978991 TI |
243 | if (max > 0) |
244 | preallocate_info_init(substream); | |
0dba808e TI |
245 | if (managed) |
246 | substream->managed_buffer_alloc = 1; | |
1da177e4 LT |
247 | } |
248 | ||
0dba808e TI |
249 | static void preallocate_pages_for_all(struct snd_pcm *pcm, int type, |
250 | void *data, size_t size, size_t max, | |
251 | bool managed) | |
252 | { | |
253 | struct snd_pcm_substream *substream; | |
254 | int stream; | |
255 | ||
256 | for (stream = 0; stream < 2; stream++) | |
257 | for (substream = pcm->streams[stream].substream; substream; | |
258 | substream = substream->next) | |
259 | preallocate_pages(substream, type, data, size, max, | |
260 | managed); | |
261 | } | |
1da177e4 LT |
262 | |
263 | /** | |
264 | * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type | |
265 | * @substream: the pcm substream instance | |
266 | * @type: DMA type (SNDRV_DMA_TYPE_*) | |
25985edc | 267 | * @data: DMA type dependent data |
1da177e4 LT |
268 | * @size: the requested pre-allocation size in bytes |
269 | * @max: the max. allowed pre-allocation size | |
270 | * | |
271 | * Do pre-allocation for the given DMA buffer type. | |
1da177e4 | 272 | */ |
bb580602 | 273 | void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream, |
1da177e4 LT |
274 | int type, struct device *data, |
275 | size_t size, size_t max) | |
276 | { | |
0dba808e | 277 | preallocate_pages(substream, type, data, size, max, false); |
1da177e4 | 278 | } |
e88e8ae6 TI |
279 | EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages); |
280 | ||
1da177e4 | 281 | /** |
25985edc | 282 | * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams) |
df8db936 | 283 | * @pcm: the pcm instance |
1da177e4 | 284 | * @type: DMA type (SNDRV_DMA_TYPE_*) |
25985edc | 285 | * @data: DMA type dependent data |
1da177e4 LT |
286 | * @size: the requested pre-allocation size in bytes |
287 | * @max: the max. allowed pre-allocation size | |
288 | * | |
289 | * Do pre-allocation to all substreams of the given pcm for the | |
290 | * specified DMA type. | |
1da177e4 | 291 | */ |
bb580602 | 292 | void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm, |
1da177e4 LT |
293 | int type, void *data, |
294 | size_t size, size_t max) | |
295 | { | |
0dba808e | 296 | preallocate_pages_for_all(pcm, type, data, size, max, false); |
1da177e4 | 297 | } |
e88e8ae6 TI |
298 | EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all); |
299 | ||
0dba808e TI |
300 | /** |
301 | * snd_pcm_set_managed_buffer - set up buffer management for a substream | |
302 | * @substream: the pcm substream instance | |
303 | * @type: DMA type (SNDRV_DMA_TYPE_*) | |
304 | * @data: DMA type dependent data | |
305 | * @size: the requested pre-allocation size in bytes | |
306 | * @max: the max. allowed pre-allocation size | |
307 | * | |
308 | * Do pre-allocation for the given DMA buffer type, and set the managed | |
309 | * buffer allocation mode to the given substream. | |
310 | * In this mode, PCM core will allocate a buffer automatically before PCM | |
311 | * hw_params ops call, and release the buffer after PCM hw_free ops call | |
312 | * as well, so that the driver doesn't need to invoke the allocation and | |
313 | * the release explicitly in its callback. | |
314 | * When a buffer is actually allocated before the PCM hw_params call, it | |
315 | * turns on the runtime buffer_changed flag for drivers changing their h/w | |
316 | * parameters accordingly. | |
317 | */ | |
318 | void snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type, | |
319 | struct device *data, size_t size, size_t max) | |
320 | { | |
321 | preallocate_pages(substream, type, data, size, max, true); | |
322 | } | |
323 | EXPORT_SYMBOL(snd_pcm_set_managed_buffer); | |
324 | ||
325 | /** | |
326 | * snd_pcm_set_managed_buffer_all - set up buffer management for all substreams | |
327 | * for all substreams | |
328 | * @pcm: the pcm instance | |
329 | * @type: DMA type (SNDRV_DMA_TYPE_*) | |
330 | * @data: DMA type dependent data | |
331 | * @size: the requested pre-allocation size in bytes | |
332 | * @max: the max. allowed pre-allocation size | |
333 | * | |
334 | * Do pre-allocation to all substreams of the given pcm for the specified DMA | |
335 | * type and size, and set the managed_buffer_alloc flag to each substream. | |
336 | */ | |
337 | void snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type, | |
338 | struct device *data, | |
339 | size_t size, size_t max) | |
340 | { | |
341 | preallocate_pages_for_all(pcm, type, data, size, max, true); | |
342 | } | |
343 | EXPORT_SYMBOL(snd_pcm_set_managed_buffer_all); | |
344 | ||
cc6a8acd | 345 | #ifdef CONFIG_SND_DMA_SGBUF |
fc7af6bc | 346 | /* |
1da177e4 LT |
347 | * snd_pcm_sgbuf_ops_page - get the page struct at the given offset |
348 | * @substream: the pcm substream instance | |
349 | * @offset: the buffer offset | |
350 | * | |
1da177e4 | 351 | * Used as the page callback of PCM ops. |
eb7c06e8 YB |
352 | * |
353 | * Return: The page struct at the given buffer offset. %NULL on failure. | |
1da177e4 | 354 | */ |
877211f5 | 355 | struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset) |
1da177e4 LT |
356 | { |
357 | struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream); | |
358 | ||
359 | unsigned int idx = offset >> PAGE_SHIFT; | |
360 | if (idx >= (unsigned int)sgbuf->pages) | |
361 | return NULL; | |
362 | return sgbuf->page_table[idx]; | |
363 | } | |
cc6a8acd | 364 | #endif /* CONFIG_SND_DMA_SGBUF */ |
51e9f2e6 | 365 | |
1da177e4 LT |
366 | /** |
367 | * snd_pcm_lib_malloc_pages - allocate the DMA buffer | |
368 | * @substream: the substream to allocate the DMA buffer to | |
369 | * @size: the requested buffer size in bytes | |
370 | * | |
371 | * Allocates the DMA buffer on the BUS type given earlier to | |
372 | * snd_pcm_lib_preallocate_xxx_pages(). | |
373 | * | |
eb7c06e8 | 374 | * Return: 1 if the buffer is changed, 0 if not changed, or a negative |
1da177e4 LT |
375 | * code on failure. |
376 | */ | |
877211f5 | 377 | int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size) |
1da177e4 | 378 | { |
d4cfb30f | 379 | struct snd_card *card = substream->pcm->card; |
877211f5 | 380 | struct snd_pcm_runtime *runtime; |
1da177e4 LT |
381 | struct snd_dma_buffer *dmab = NULL; |
382 | ||
7eaa943c TI |
383 | if (PCM_RUNTIME_CHECK(substream)) |
384 | return -EINVAL; | |
385 | if (snd_BUG_ON(substream->dma_buffer.dev.type == | |
386 | SNDRV_DMA_TYPE_UNKNOWN)) | |
387 | return -EINVAL; | |
1da177e4 | 388 | runtime = substream->runtime; |
1da177e4 LT |
389 | |
390 | if (runtime->dma_buffer_p) { | |
391 | /* perphaps, we might free the large DMA memory region | |
392 | to save some space here, but the actual solution | |
393 | costs us less time */ | |
394 | if (runtime->dma_buffer_p->bytes >= size) { | |
395 | runtime->dma_bytes = size; | |
396 | return 0; /* ok, do not change */ | |
397 | } | |
398 | snd_pcm_lib_free_pages(substream); | |
399 | } | |
877211f5 TI |
400 | if (substream->dma_buffer.area != NULL && |
401 | substream->dma_buffer.bytes >= size) { | |
1da177e4 LT |
402 | dmab = &substream->dma_buffer; /* use the pre-allocated buffer */ |
403 | } else { | |
ca2c0966 | 404 | dmab = kzalloc(sizeof(*dmab), GFP_KERNEL); |
1da177e4 LT |
405 | if (! dmab) |
406 | return -ENOMEM; | |
407 | dmab->dev = substream->dma_buffer.dev; | |
d4cfb30f TI |
408 | if (do_alloc_pages(card, |
409 | substream->dma_buffer.dev.type, | |
410 | substream->dma_buffer.dev.dev, | |
411 | size, dmab) < 0) { | |
1da177e4 LT |
412 | kfree(dmab); |
413 | return -ENOMEM; | |
414 | } | |
415 | } | |
416 | snd_pcm_set_runtime_buffer(substream, dmab); | |
417 | runtime->dma_bytes = size; | |
418 | return 1; /* area was changed */ | |
419 | } | |
e88e8ae6 TI |
420 | EXPORT_SYMBOL(snd_pcm_lib_malloc_pages); |
421 | ||
1da177e4 LT |
422 | /** |
423 | * snd_pcm_lib_free_pages - release the allocated DMA buffer. | |
424 | * @substream: the substream to release the DMA buffer | |
425 | * | |
426 | * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages(). | |
427 | * | |
eb7c06e8 | 428 | * Return: Zero if successful, or a negative error code on failure. |
1da177e4 | 429 | */ |
877211f5 | 430 | int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream) |
1da177e4 | 431 | { |
d4cfb30f | 432 | struct snd_card *card = substream->pcm->card; |
877211f5 | 433 | struct snd_pcm_runtime *runtime; |
1da177e4 | 434 | |
7eaa943c TI |
435 | if (PCM_RUNTIME_CHECK(substream)) |
436 | return -EINVAL; | |
1da177e4 | 437 | runtime = substream->runtime; |
1da177e4 LT |
438 | if (runtime->dma_area == NULL) |
439 | return 0; | |
440 | if (runtime->dma_buffer_p != &substream->dma_buffer) { | |
441 | /* it's a newly allocated buffer. release it now. */ | |
d4cfb30f | 442 | do_free_pages(card, runtime->dma_buffer_p); |
1da177e4 LT |
443 | kfree(runtime->dma_buffer_p); |
444 | } | |
445 | snd_pcm_set_runtime_buffer(substream, NULL); | |
446 | return 0; | |
447 | } | |
e88e8ae6 | 448 | EXPORT_SYMBOL(snd_pcm_lib_free_pages); |
681b84e1 CL |
449 | |
450 | int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream, | |
451 | size_t size, gfp_t gfp_flags) | |
452 | { | |
453 | struct snd_pcm_runtime *runtime; | |
454 | ||
455 | if (PCM_RUNTIME_CHECK(substream)) | |
456 | return -EINVAL; | |
457 | runtime = substream->runtime; | |
458 | if (runtime->dma_area) { | |
459 | if (runtime->dma_bytes >= size) | |
460 | return 0; /* already large enough */ | |
461 | vfree(runtime->dma_area); | |
462 | } | |
88dca4ca | 463 | runtime->dma_area = __vmalloc(size, gfp_flags); |
681b84e1 CL |
464 | if (!runtime->dma_area) |
465 | return -ENOMEM; | |
466 | runtime->dma_bytes = size; | |
467 | return 1; | |
468 | } | |
469 | EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer); | |
470 | ||
471 | /** | |
472 | * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer | |
473 | * @substream: the substream with a buffer allocated by | |
474 | * snd_pcm_lib_alloc_vmalloc_buffer() | |
eb7c06e8 YB |
475 | * |
476 | * Return: Zero if successful, or a negative error code on failure. | |
681b84e1 CL |
477 | */ |
478 | int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream) | |
479 | { | |
480 | struct snd_pcm_runtime *runtime; | |
481 | ||
482 | if (PCM_RUNTIME_CHECK(substream)) | |
483 | return -EINVAL; | |
484 | runtime = substream->runtime; | |
485 | vfree(runtime->dma_area); | |
486 | runtime->dma_area = NULL; | |
487 | return 0; | |
488 | } | |
489 | EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer); | |
490 | ||
491 | /** | |
492 | * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct | |
493 | * @substream: the substream with a buffer allocated by | |
494 | * snd_pcm_lib_alloc_vmalloc_buffer() | |
495 | * @offset: offset in the buffer | |
496 | * | |
497 | * This function is to be used as the page callback in the PCM ops. | |
eb7c06e8 YB |
498 | * |
499 | * Return: The page struct, or %NULL on failure. | |
681b84e1 CL |
500 | */ |
501 | struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream, | |
502 | unsigned long offset) | |
503 | { | |
504 | return vmalloc_to_page(substream->runtime->dma_area + offset); | |
505 | } | |
506 | EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page); |