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> |
3ad796cb | 14 | #include <linux/dma-mapping.h> |
1da177e4 LT |
15 | #include <sound/core.h> |
16 | #include <sound/pcm.h> | |
17 | #include <sound/info.h> | |
18 | #include <sound/initval.h> | |
0821fd77 | 19 | #include "pcm_local.h" |
1da177e4 LT |
20 | |
21 | static int preallocate_dma = 1; | |
22 | module_param(preallocate_dma, int, 0444); | |
23 | MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized."); | |
24 | ||
25 | static int maximum_substreams = 4; | |
26 | module_param(maximum_substreams, int, 0444); | |
27 | MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory."); | |
28 | ||
29 | static const size_t snd_minimum_buffer = 16384; | |
30 | ||
d4cfb30f TI |
31 | static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL; |
32 | module_param(max_alloc_per_card, ulong, 0644); | |
33 | MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card."); | |
34 | ||
35 | static int do_alloc_pages(struct snd_card *card, int type, struct device *dev, | |
36 | size_t size, struct snd_dma_buffer *dmab) | |
37 | { | |
38 | int err; | |
39 | ||
40 | if (max_alloc_per_card && | |
41 | card->total_pcm_alloc_bytes + size > max_alloc_per_card) | |
42 | return -ENOMEM; | |
3ad796cb TI |
43 | |
44 | if (IS_ENABLED(CONFIG_SND_DMA_SGBUF) && | |
45 | (type == SNDRV_DMA_TYPE_DEV_SG || type == SNDRV_DMA_TYPE_DEV_UC_SG) && | |
46 | !dma_is_direct(get_dma_ops(dev))) { | |
47 | /* mutate to continuous page allocation */ | |
48 | dev_dbg(dev, "Use continuous page allocator\n"); | |
49 | if (type == SNDRV_DMA_TYPE_DEV_SG) | |
50 | type = SNDRV_DMA_TYPE_DEV; | |
51 | else | |
52 | type = SNDRV_DMA_TYPE_DEV_UC; | |
53 | } | |
54 | ||
d4cfb30f TI |
55 | err = snd_dma_alloc_pages(type, dev, size, dmab); |
56 | if (!err) { | |
57 | mutex_lock(&card->memory_mutex); | |
58 | card->total_pcm_alloc_bytes += dmab->bytes; | |
59 | mutex_unlock(&card->memory_mutex); | |
60 | } | |
61 | return err; | |
62 | } | |
63 | ||
64 | static void do_free_pages(struct snd_card *card, struct snd_dma_buffer *dmab) | |
65 | { | |
66 | if (!dmab->area) | |
67 | return; | |
68 | mutex_lock(&card->memory_mutex); | |
69 | WARN_ON(card->total_pcm_alloc_bytes < dmab->bytes); | |
70 | card->total_pcm_alloc_bytes -= dmab->bytes; | |
71 | mutex_unlock(&card->memory_mutex); | |
72 | snd_dma_free_pages(dmab); | |
73 | dmab->area = NULL; | |
74 | } | |
1da177e4 LT |
75 | |
76 | /* | |
77 | * try to allocate as the large pages as possible. | |
78 | * stores the resultant memory size in *res_size. | |
79 | * | |
80 | * the minimum size is snd_minimum_buffer. it should be power of 2. | |
81 | */ | |
877211f5 | 82 | static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size) |
1da177e4 LT |
83 | { |
84 | struct snd_dma_buffer *dmab = &substream->dma_buffer; | |
d4cfb30f | 85 | struct snd_card *card = substream->pcm->card; |
6ab08ced | 86 | size_t orig_size = size; |
1da177e4 LT |
87 | int err; |
88 | ||
1da177e4 | 89 | do { |
d4cfb30f TI |
90 | err = do_alloc_pages(card, dmab->dev.type, dmab->dev.dev, |
91 | size, dmab); | |
92 | if (err != -ENOMEM) | |
93 | return err; | |
1da177e4 LT |
94 | size >>= 1; |
95 | } while (size >= snd_minimum_buffer); | |
96 | dmab->bytes = 0; /* tell error */ | |
6ab08ced TI |
97 | pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n", |
98 | substream->pcm->card->number, substream->pcm->device, | |
99 | substream->stream ? 'c' : 'p', substream->number, | |
100 | substream->pcm->name, orig_size); | |
1da177e4 LT |
101 | return 0; |
102 | } | |
103 | ||
104 | /* | |
105 | * release the preallocated buffer if not yet done. | |
106 | */ | |
877211f5 | 107 | static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream) |
1da177e4 | 108 | { |
d4cfb30f | 109 | do_free_pages(substream->pcm->card, &substream->dma_buffer); |
1da177e4 LT |
110 | } |
111 | ||
112 | /** | |
113 | * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream. | |
114 | * @substream: the pcm substream instance | |
115 | * | |
116 | * Releases the pre-allocated buffer of the given substream. | |
1da177e4 | 117 | */ |
bb580602 | 118 | void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream) |
1da177e4 LT |
119 | { |
120 | snd_pcm_lib_preallocate_dma_free(substream); | |
1da177e4 LT |
121 | } |
122 | ||
123 | /** | |
124 | * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm | |
125 | * @pcm: the pcm instance | |
126 | * | |
127 | * Releases all the pre-allocated buffers on the given pcm. | |
1da177e4 | 128 | */ |
bb580602 | 129 | void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm) |
1da177e4 | 130 | { |
877211f5 | 131 | struct snd_pcm_substream *substream; |
1da177e4 LT |
132 | int stream; |
133 | ||
134 | for (stream = 0; stream < 2; stream++) | |
135 | for (substream = pcm->streams[stream].substream; substream; substream = substream->next) | |
136 | snd_pcm_lib_preallocate_free(substream); | |
1da177e4 | 137 | } |
e88e8ae6 TI |
138 | EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all); |
139 | ||
b7d90a35 | 140 | #ifdef CONFIG_SND_VERBOSE_PROCFS |
1da177e4 LT |
141 | /* |
142 | * read callback for prealloc proc file | |
143 | * | |
144 | * prints the current allocated size in kB. | |
145 | */ | |
877211f5 TI |
146 | static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry, |
147 | struct snd_info_buffer *buffer) | |
1da177e4 | 148 | { |
877211f5 | 149 | struct snd_pcm_substream *substream = entry->private_data; |
1da177e4 LT |
150 | snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024); |
151 | } | |
152 | ||
c7132aeb JK |
153 | /* |
154 | * read callback for prealloc_max proc file | |
155 | * | |
156 | * prints the maximum allowed size in kB. | |
157 | */ | |
158 | static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry, | |
159 | struct snd_info_buffer *buffer) | |
160 | { | |
161 | struct snd_pcm_substream *substream = entry->private_data; | |
162 | snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024); | |
163 | } | |
164 | ||
1da177e4 LT |
165 | /* |
166 | * write callback for prealloc proc file | |
167 | * | |
168 | * accepts the preallocation size in kB. | |
169 | */ | |
877211f5 TI |
170 | static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry, |
171 | struct snd_info_buffer *buffer) | |
1da177e4 | 172 | { |
877211f5 | 173 | struct snd_pcm_substream *substream = entry->private_data; |
d4cfb30f | 174 | struct snd_card *card = substream->pcm->card; |
1da177e4 LT |
175 | char line[64], str[64]; |
176 | size_t size; | |
177 | struct snd_dma_buffer new_dmab; | |
178 | ||
179 | if (substream->runtime) { | |
180 | buffer->error = -EBUSY; | |
181 | return; | |
182 | } | |
183 | if (!snd_info_get_line(buffer, line, sizeof(line))) { | |
184 | snd_info_get_str(str, line, sizeof(str)); | |
185 | size = simple_strtoul(str, NULL, 10) * 1024; | |
186 | if ((size != 0 && size < 8192) || size > substream->dma_max) { | |
187 | buffer->error = -EINVAL; | |
188 | return; | |
189 | } | |
190 | if (substream->dma_buffer.bytes == size) | |
191 | return; | |
192 | memset(&new_dmab, 0, sizeof(new_dmab)); | |
193 | new_dmab.dev = substream->dma_buffer.dev; | |
194 | if (size > 0) { | |
d4cfb30f TI |
195 | if (do_alloc_pages(card, |
196 | substream->dma_buffer.dev.type, | |
197 | substream->dma_buffer.dev.dev, | |
198 | size, &new_dmab) < 0) { | |
1da177e4 LT |
199 | buffer->error = -ENOMEM; |
200 | return; | |
201 | } | |
202 | substream->buffer_bytes_max = size; | |
203 | } else { | |
204 | substream->buffer_bytes_max = UINT_MAX; | |
205 | } | |
206 | if (substream->dma_buffer.area) | |
d4cfb30f | 207 | do_free_pages(card, &substream->dma_buffer); |
1da177e4 LT |
208 | substream->dma_buffer = new_dmab; |
209 | } else { | |
210 | buffer->error = -EINVAL; | |
211 | } | |
212 | } | |
213 | ||
e28563cc | 214 | static inline void preallocate_info_init(struct snd_pcm_substream *substream) |
1da177e4 | 215 | { |
877211f5 | 216 | struct snd_info_entry *entry; |
1da177e4 | 217 | |
a8d14981 TI |
218 | entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", |
219 | substream->proc_root); | |
220 | if (entry) { | |
221 | snd_info_set_text_ops(entry, substream, | |
222 | snd_pcm_lib_preallocate_proc_read); | |
1da177e4 | 223 | entry->c.text.write = snd_pcm_lib_preallocate_proc_write; |
6a73cf46 | 224 | entry->mode |= 0200; |
c7132aeb | 225 | } |
a8d14981 TI |
226 | entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", |
227 | substream->proc_root); | |
228 | if (entry) | |
229 | snd_info_set_text_ops(entry, substream, | |
230 | snd_pcm_lib_preallocate_max_proc_read); | |
e28563cc TI |
231 | } |
232 | ||
b7d90a35 | 233 | #else /* !CONFIG_SND_VERBOSE_PROCFS */ |
e28563cc | 234 | #define preallocate_info_init(s) |
b7d90a35 | 235 | #endif /* CONFIG_SND_VERBOSE_PROCFS */ |
e28563cc TI |
236 | |
237 | /* | |
238 | * pre-allocate the buffer and create a proc file for the substream | |
239 | */ | |
0dba808e TI |
240 | static void preallocate_pages(struct snd_pcm_substream *substream, |
241 | int type, struct device *data, | |
242 | size_t size, size_t max, bool managed) | |
e28563cc | 243 | { |
0dba808e TI |
244 | if (snd_BUG_ON(substream->dma_buffer.dev.type)) |
245 | return; | |
246 | ||
247 | substream->dma_buffer.dev.type = type; | |
248 | substream->dma_buffer.dev.dev = data; | |
e28563cc TI |
249 | |
250 | if (size > 0 && preallocate_dma && substream->number < maximum_substreams) | |
251 | preallocate_pcm_pages(substream, size); | |
252 | ||
253 | if (substream->dma_buffer.bytes > 0) | |
254 | substream->buffer_bytes_max = substream->dma_buffer.bytes; | |
255 | substream->dma_max = max; | |
d3978991 TI |
256 | if (max > 0) |
257 | preallocate_info_init(substream); | |
0dba808e TI |
258 | if (managed) |
259 | substream->managed_buffer_alloc = 1; | |
1da177e4 LT |
260 | } |
261 | ||
0dba808e TI |
262 | static void preallocate_pages_for_all(struct snd_pcm *pcm, int type, |
263 | void *data, size_t size, size_t max, | |
264 | bool managed) | |
265 | { | |
266 | struct snd_pcm_substream *substream; | |
267 | int stream; | |
268 | ||
269 | for (stream = 0; stream < 2; stream++) | |
270 | for (substream = pcm->streams[stream].substream; substream; | |
271 | substream = substream->next) | |
272 | preallocate_pages(substream, type, data, size, max, | |
273 | managed); | |
274 | } | |
1da177e4 LT |
275 | |
276 | /** | |
277 | * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type | |
278 | * @substream: the pcm substream instance | |
279 | * @type: DMA type (SNDRV_DMA_TYPE_*) | |
25985edc | 280 | * @data: DMA type dependent data |
1da177e4 LT |
281 | * @size: the requested pre-allocation size in bytes |
282 | * @max: the max. allowed pre-allocation size | |
283 | * | |
284 | * Do pre-allocation for the given DMA buffer type. | |
1da177e4 | 285 | */ |
bb580602 | 286 | void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream, |
1da177e4 LT |
287 | int type, struct device *data, |
288 | size_t size, size_t max) | |
289 | { | |
0dba808e | 290 | preallocate_pages(substream, type, data, size, max, false); |
1da177e4 | 291 | } |
e88e8ae6 TI |
292 | EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages); |
293 | ||
1da177e4 | 294 | /** |
25985edc | 295 | * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams) |
df8db936 | 296 | * @pcm: the pcm instance |
1da177e4 | 297 | * @type: DMA type (SNDRV_DMA_TYPE_*) |
25985edc | 298 | * @data: DMA type dependent data |
1da177e4 LT |
299 | * @size: the requested pre-allocation size in bytes |
300 | * @max: the max. allowed pre-allocation size | |
301 | * | |
302 | * Do pre-allocation to all substreams of the given pcm for the | |
303 | * specified DMA type. | |
1da177e4 | 304 | */ |
bb580602 | 305 | void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm, |
1da177e4 LT |
306 | int type, void *data, |
307 | size_t size, size_t max) | |
308 | { | |
0dba808e | 309 | preallocate_pages_for_all(pcm, type, data, size, max, false); |
1da177e4 | 310 | } |
e88e8ae6 TI |
311 | EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all); |
312 | ||
0dba808e TI |
313 | /** |
314 | * snd_pcm_set_managed_buffer - set up buffer management for a substream | |
315 | * @substream: the pcm substream instance | |
316 | * @type: DMA type (SNDRV_DMA_TYPE_*) | |
317 | * @data: DMA type dependent data | |
318 | * @size: the requested pre-allocation size in bytes | |
319 | * @max: the max. allowed pre-allocation size | |
320 | * | |
321 | * Do pre-allocation for the given DMA buffer type, and set the managed | |
322 | * buffer allocation mode to the given substream. | |
323 | * In this mode, PCM core will allocate a buffer automatically before PCM | |
324 | * hw_params ops call, and release the buffer after PCM hw_free ops call | |
325 | * as well, so that the driver doesn't need to invoke the allocation and | |
326 | * the release explicitly in its callback. | |
327 | * When a buffer is actually allocated before the PCM hw_params call, it | |
328 | * turns on the runtime buffer_changed flag for drivers changing their h/w | |
329 | * parameters accordingly. | |
330 | */ | |
331 | void snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type, | |
332 | struct device *data, size_t size, size_t max) | |
333 | { | |
334 | preallocate_pages(substream, type, data, size, max, true); | |
335 | } | |
336 | EXPORT_SYMBOL(snd_pcm_set_managed_buffer); | |
337 | ||
338 | /** | |
339 | * snd_pcm_set_managed_buffer_all - set up buffer management for all substreams | |
340 | * for all substreams | |
341 | * @pcm: the pcm instance | |
342 | * @type: DMA type (SNDRV_DMA_TYPE_*) | |
343 | * @data: DMA type dependent data | |
344 | * @size: the requested pre-allocation size in bytes | |
345 | * @max: the max. allowed pre-allocation size | |
346 | * | |
347 | * Do pre-allocation to all substreams of the given pcm for the specified DMA | |
348 | * type and size, and set the managed_buffer_alloc flag to each substream. | |
349 | */ | |
350 | void snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type, | |
351 | struct device *data, | |
352 | size_t size, size_t max) | |
353 | { | |
354 | preallocate_pages_for_all(pcm, type, data, size, max, true); | |
355 | } | |
356 | EXPORT_SYMBOL(snd_pcm_set_managed_buffer_all); | |
357 | ||
cc6a8acd | 358 | #ifdef CONFIG_SND_DMA_SGBUF |
fc7af6bc | 359 | /* |
1da177e4 LT |
360 | * snd_pcm_sgbuf_ops_page - get the page struct at the given offset |
361 | * @substream: the pcm substream instance | |
362 | * @offset: the buffer offset | |
363 | * | |
1da177e4 | 364 | * Used as the page callback of PCM ops. |
eb7c06e8 YB |
365 | * |
366 | * Return: The page struct at the given buffer offset. %NULL on failure. | |
1da177e4 | 367 | */ |
877211f5 | 368 | struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset) |
1da177e4 LT |
369 | { |
370 | struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream); | |
371 | ||
372 | unsigned int idx = offset >> PAGE_SHIFT; | |
373 | if (idx >= (unsigned int)sgbuf->pages) | |
374 | return NULL; | |
375 | return sgbuf->page_table[idx]; | |
376 | } | |
cc6a8acd | 377 | #endif /* CONFIG_SND_DMA_SGBUF */ |
51e9f2e6 | 378 | |
1da177e4 LT |
379 | /** |
380 | * snd_pcm_lib_malloc_pages - allocate the DMA buffer | |
381 | * @substream: the substream to allocate the DMA buffer to | |
382 | * @size: the requested buffer size in bytes | |
383 | * | |
384 | * Allocates the DMA buffer on the BUS type given earlier to | |
385 | * snd_pcm_lib_preallocate_xxx_pages(). | |
386 | * | |
eb7c06e8 | 387 | * Return: 1 if the buffer is changed, 0 if not changed, or a negative |
1da177e4 LT |
388 | * code on failure. |
389 | */ | |
877211f5 | 390 | int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size) |
1da177e4 | 391 | { |
d4cfb30f | 392 | struct snd_card *card = substream->pcm->card; |
877211f5 | 393 | struct snd_pcm_runtime *runtime; |
1da177e4 LT |
394 | struct snd_dma_buffer *dmab = NULL; |
395 | ||
7eaa943c TI |
396 | if (PCM_RUNTIME_CHECK(substream)) |
397 | return -EINVAL; | |
398 | if (snd_BUG_ON(substream->dma_buffer.dev.type == | |
399 | SNDRV_DMA_TYPE_UNKNOWN)) | |
400 | return -EINVAL; | |
1da177e4 | 401 | runtime = substream->runtime; |
1da177e4 LT |
402 | |
403 | if (runtime->dma_buffer_p) { | |
404 | /* perphaps, we might free the large DMA memory region | |
405 | to save some space here, but the actual solution | |
406 | costs us less time */ | |
407 | if (runtime->dma_buffer_p->bytes >= size) { | |
408 | runtime->dma_bytes = size; | |
409 | return 0; /* ok, do not change */ | |
410 | } | |
411 | snd_pcm_lib_free_pages(substream); | |
412 | } | |
877211f5 TI |
413 | if (substream->dma_buffer.area != NULL && |
414 | substream->dma_buffer.bytes >= size) { | |
1da177e4 LT |
415 | dmab = &substream->dma_buffer; /* use the pre-allocated buffer */ |
416 | } else { | |
ca2c0966 | 417 | dmab = kzalloc(sizeof(*dmab), GFP_KERNEL); |
1da177e4 LT |
418 | if (! dmab) |
419 | return -ENOMEM; | |
420 | dmab->dev = substream->dma_buffer.dev; | |
d4cfb30f TI |
421 | if (do_alloc_pages(card, |
422 | substream->dma_buffer.dev.type, | |
423 | substream->dma_buffer.dev.dev, | |
424 | size, dmab) < 0) { | |
1da177e4 LT |
425 | kfree(dmab); |
426 | return -ENOMEM; | |
427 | } | |
428 | } | |
429 | snd_pcm_set_runtime_buffer(substream, dmab); | |
430 | runtime->dma_bytes = size; | |
431 | return 1; /* area was changed */ | |
432 | } | |
e88e8ae6 TI |
433 | EXPORT_SYMBOL(snd_pcm_lib_malloc_pages); |
434 | ||
1da177e4 LT |
435 | /** |
436 | * snd_pcm_lib_free_pages - release the allocated DMA buffer. | |
437 | * @substream: the substream to release the DMA buffer | |
438 | * | |
439 | * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages(). | |
440 | * | |
eb7c06e8 | 441 | * Return: Zero if successful, or a negative error code on failure. |
1da177e4 | 442 | */ |
877211f5 | 443 | int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream) |
1da177e4 | 444 | { |
d4cfb30f | 445 | struct snd_card *card = substream->pcm->card; |
877211f5 | 446 | struct snd_pcm_runtime *runtime; |
1da177e4 | 447 | |
7eaa943c TI |
448 | if (PCM_RUNTIME_CHECK(substream)) |
449 | return -EINVAL; | |
1da177e4 | 450 | runtime = substream->runtime; |
1da177e4 LT |
451 | if (runtime->dma_area == NULL) |
452 | return 0; | |
453 | if (runtime->dma_buffer_p != &substream->dma_buffer) { | |
454 | /* it's a newly allocated buffer. release it now. */ | |
d4cfb30f | 455 | do_free_pages(card, runtime->dma_buffer_p); |
1da177e4 LT |
456 | kfree(runtime->dma_buffer_p); |
457 | } | |
458 | snd_pcm_set_runtime_buffer(substream, NULL); | |
459 | return 0; | |
460 | } | |
e88e8ae6 | 461 | EXPORT_SYMBOL(snd_pcm_lib_free_pages); |
681b84e1 CL |
462 | |
463 | int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream, | |
464 | size_t size, gfp_t gfp_flags) | |
465 | { | |
466 | struct snd_pcm_runtime *runtime; | |
467 | ||
468 | if (PCM_RUNTIME_CHECK(substream)) | |
469 | return -EINVAL; | |
470 | runtime = substream->runtime; | |
471 | if (runtime->dma_area) { | |
472 | if (runtime->dma_bytes >= size) | |
473 | return 0; /* already large enough */ | |
474 | vfree(runtime->dma_area); | |
475 | } | |
88dca4ca | 476 | runtime->dma_area = __vmalloc(size, gfp_flags); |
681b84e1 CL |
477 | if (!runtime->dma_area) |
478 | return -ENOMEM; | |
479 | runtime->dma_bytes = size; | |
480 | return 1; | |
481 | } | |
482 | EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer); | |
483 | ||
484 | /** | |
485 | * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer | |
486 | * @substream: the substream with a buffer allocated by | |
487 | * snd_pcm_lib_alloc_vmalloc_buffer() | |
eb7c06e8 YB |
488 | * |
489 | * Return: Zero if successful, or a negative error code on failure. | |
681b84e1 CL |
490 | */ |
491 | int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream) | |
492 | { | |
493 | struct snd_pcm_runtime *runtime; | |
494 | ||
495 | if (PCM_RUNTIME_CHECK(substream)) | |
496 | return -EINVAL; | |
497 | runtime = substream->runtime; | |
498 | vfree(runtime->dma_area); | |
499 | runtime->dma_area = NULL; | |
500 | return 0; | |
501 | } | |
502 | EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer); | |
503 | ||
504 | /** | |
505 | * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct | |
506 | * @substream: the substream with a buffer allocated by | |
507 | * snd_pcm_lib_alloc_vmalloc_buffer() | |
508 | * @offset: offset in the buffer | |
509 | * | |
510 | * This function is to be used as the page callback in the PCM ops. | |
eb7c06e8 YB |
511 | * |
512 | * Return: The page struct, or %NULL on failure. | |
681b84e1 CL |
513 | */ |
514 | struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream, | |
515 | unsigned long offset) | |
516 | { | |
517 | return vmalloc_to_page(substream->runtime->dma_area + offset); | |
518 | } | |
519 | EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page); |