2 * Digital Audio (PCM) abstract layer
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
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.
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.
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
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>
34 static int preallocate_dma
= 1;
35 module_param(preallocate_dma
, int, 0444);
36 MODULE_PARM_DESC(preallocate_dma
, "Preallocate DMA memory when the PCM devices are initialized.");
38 static int maximum_substreams
= 4;
39 module_param(maximum_substreams
, int, 0444);
40 MODULE_PARM_DESC(maximum_substreams
, "Maximum substreams with preallocated DMA memory.");
42 static const size_t snd_minimum_buffer
= 16384;
46 * try to allocate as the large pages as possible.
47 * stores the resultant memory size in *res_size.
49 * the minimum size is snd_minimum_buffer. it should be power of 2.
51 static int preallocate_pcm_pages(struct snd_pcm_substream
*substream
, size_t size
)
53 struct snd_dma_buffer
*dmab
= &substream
->dma_buffer
;
56 /* already reserved? */
57 if (snd_dma_get_reserved_buf(dmab
, substream
->dma_buf_id
) > 0) {
58 if (dmab
->bytes
>= size
)
60 /* no, free the reserved block */
61 snd_dma_free_pages(dmab
);
66 if ((err
= snd_dma_alloc_pages(dmab
->dev
.type
, dmab
->dev
.dev
,
69 return err
; /* fatal error */
73 } while (size
>= snd_minimum_buffer
);
74 dmab
->bytes
= 0; /* tell error */
79 * release the preallocated buffer if not yet done.
81 static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream
*substream
)
83 if (substream
->dma_buffer
.area
== NULL
)
85 if (substream
->dma_buf_id
)
86 snd_dma_reserve_buf(&substream
->dma_buffer
, substream
->dma_buf_id
);
88 snd_dma_free_pages(&substream
->dma_buffer
);
89 substream
->dma_buffer
.area
= NULL
;
93 * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
94 * @substream: the pcm substream instance
96 * Releases the pre-allocated buffer of the given substream.
98 * Returns zero if successful, or a negative error code on failure.
100 int snd_pcm_lib_preallocate_free(struct snd_pcm_substream
*substream
)
102 snd_pcm_lib_preallocate_dma_free(substream
);
103 #ifdef CONFIG_SND_VERBOSE_PROCFS
104 snd_info_free_entry(substream
->proc_prealloc_max_entry
);
105 substream
->proc_prealloc_max_entry
= NULL
;
106 snd_info_free_entry(substream
->proc_prealloc_entry
);
107 substream
->proc_prealloc_entry
= NULL
;
113 * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
114 * @pcm: the pcm instance
116 * Releases all the pre-allocated buffers on the given pcm.
118 * Returns zero if successful, or a negative error code on failure.
120 int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm
*pcm
)
122 struct snd_pcm_substream
*substream
;
125 for (stream
= 0; stream
< 2; stream
++)
126 for (substream
= pcm
->streams
[stream
].substream
; substream
; substream
= substream
->next
)
127 snd_pcm_lib_preallocate_free(substream
);
131 EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all
);
133 #ifdef CONFIG_SND_VERBOSE_PROCFS
135 * read callback for prealloc proc file
137 * prints the current allocated size in kB.
139 static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry
*entry
,
140 struct snd_info_buffer
*buffer
)
142 struct snd_pcm_substream
*substream
= entry
->private_data
;
143 snd_iprintf(buffer
, "%lu\n", (unsigned long) substream
->dma_buffer
.bytes
/ 1024);
147 * read callback for prealloc_max proc file
149 * prints the maximum allowed size in kB.
151 static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry
*entry
,
152 struct snd_info_buffer
*buffer
)
154 struct snd_pcm_substream
*substream
= entry
->private_data
;
155 snd_iprintf(buffer
, "%lu\n", (unsigned long) substream
->dma_max
/ 1024);
159 * write callback for prealloc proc file
161 * accepts the preallocation size in kB.
163 static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry
*entry
,
164 struct snd_info_buffer
*buffer
)
166 struct snd_pcm_substream
*substream
= entry
->private_data
;
167 char line
[64], str
[64];
169 struct snd_dma_buffer new_dmab
;
171 if (substream
->runtime
) {
172 buffer
->error
= -EBUSY
;
175 if (!snd_info_get_line(buffer
, line
, sizeof(line
))) {
176 snd_info_get_str(str
, line
, sizeof(str
));
177 size
= simple_strtoul(str
, NULL
, 10) * 1024;
178 if ((size
!= 0 && size
< 8192) || size
> substream
->dma_max
) {
179 buffer
->error
= -EINVAL
;
182 if (substream
->dma_buffer
.bytes
== size
)
184 memset(&new_dmab
, 0, sizeof(new_dmab
));
185 new_dmab
.dev
= substream
->dma_buffer
.dev
;
187 if (snd_dma_alloc_pages(substream
->dma_buffer
.dev
.type
,
188 substream
->dma_buffer
.dev
.dev
,
189 size
, &new_dmab
) < 0) {
190 buffer
->error
= -ENOMEM
;
193 substream
->buffer_bytes_max
= size
;
195 substream
->buffer_bytes_max
= UINT_MAX
;
197 if (substream
->dma_buffer
.area
)
198 snd_dma_free_pages(&substream
->dma_buffer
);
199 substream
->dma_buffer
= new_dmab
;
201 buffer
->error
= -EINVAL
;
205 static inline void preallocate_info_init(struct snd_pcm_substream
*substream
)
207 struct snd_info_entry
*entry
;
209 if ((entry
= snd_info_create_card_entry(substream
->pcm
->card
, "prealloc", substream
->proc_root
)) != NULL
) {
210 entry
->c
.text
.read
= snd_pcm_lib_preallocate_proc_read
;
211 entry
->c
.text
.write
= snd_pcm_lib_preallocate_proc_write
;
212 entry
->mode
|= S_IWUSR
;
213 entry
->private_data
= substream
;
214 if (snd_info_register(entry
) < 0) {
215 snd_info_free_entry(entry
);
219 substream
->proc_prealloc_entry
= entry
;
220 if ((entry
= snd_info_create_card_entry(substream
->pcm
->card
, "prealloc_max", substream
->proc_root
)) != NULL
) {
221 entry
->c
.text
.read
= snd_pcm_lib_preallocate_max_proc_read
;
222 entry
->private_data
= substream
;
223 if (snd_info_register(entry
) < 0) {
224 snd_info_free_entry(entry
);
228 substream
->proc_prealloc_max_entry
= entry
;
231 #else /* !CONFIG_SND_VERBOSE_PROCFS */
232 #define preallocate_info_init(s)
233 #endif /* CONFIG_SND_VERBOSE_PROCFS */
236 * pre-allocate the buffer and create a proc file for the substream
238 static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream
*substream
,
239 size_t size
, size_t max
)
242 if (size
> 0 && preallocate_dma
&& substream
->number
< maximum_substreams
)
243 preallocate_pcm_pages(substream
, size
);
245 if (substream
->dma_buffer
.bytes
> 0)
246 substream
->buffer_bytes_max
= substream
->dma_buffer
.bytes
;
247 substream
->dma_max
= max
;
248 preallocate_info_init(substream
);
254 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
255 * @substream: the pcm substream instance
256 * @type: DMA type (SNDRV_DMA_TYPE_*)
257 * @data: DMA type dependent data
258 * @size: the requested pre-allocation size in bytes
259 * @max: the max. allowed pre-allocation size
261 * Do pre-allocation for the given DMA buffer type.
263 * When substream->dma_buf_id is set, the function tries to look for
264 * the reserved buffer, and the buffer is not freed but reserved at
265 * destruction time. The dma_buf_id must be unique for all systems
266 * (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id().
268 * Returns zero if successful, or a negative error code on failure.
270 int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream
*substream
,
271 int type
, struct device
*data
,
272 size_t size
, size_t max
)
274 substream
->dma_buffer
.dev
.type
= type
;
275 substream
->dma_buffer
.dev
.dev
= data
;
276 return snd_pcm_lib_preallocate_pages1(substream
, size
, max
);
279 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages
);
282 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
283 * @pcm: the pcm instance
284 * @type: DMA type (SNDRV_DMA_TYPE_*)
285 * @data: DMA type dependent data
286 * @size: the requested pre-allocation size in bytes
287 * @max: the max. allowed pre-allocation size
289 * Do pre-allocation to all substreams of the given pcm for the
290 * specified DMA type.
292 * Returns zero if successful, or a negative error code on failure.
294 int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm
*pcm
,
295 int type
, void *data
,
296 size_t size
, size_t max
)
298 struct snd_pcm_substream
*substream
;
301 for (stream
= 0; stream
< 2; stream
++)
302 for (substream
= pcm
->streams
[stream
].substream
; substream
; substream
= substream
->next
)
303 if ((err
= snd_pcm_lib_preallocate_pages(substream
, type
, data
, size
, max
)) < 0)
308 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all
);
310 #ifdef CONFIG_SND_DMA_SGBUF
312 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
313 * @substream: the pcm substream instance
314 * @offset: the buffer offset
316 * Returns the page struct at the given buffer offset.
317 * Used as the page callback of PCM ops.
319 struct page
*snd_pcm_sgbuf_ops_page(struct snd_pcm_substream
*substream
, unsigned long offset
)
321 struct snd_sg_buf
*sgbuf
= snd_pcm_substream_sgbuf(substream
);
323 unsigned int idx
= offset
>> PAGE_SHIFT
;
324 if (idx
>= (unsigned int)sgbuf
->pages
)
326 return sgbuf
->page_table
[idx
];
329 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page
);
332 * compute the max chunk size with continuous pages on sg-buffer
334 unsigned int snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream
*substream
,
335 unsigned int ofs
, unsigned int size
)
337 struct snd_sg_buf
*sg
= snd_pcm_substream_sgbuf(substream
);
338 unsigned int start
, end
, pg
;
340 start
= ofs
>> PAGE_SHIFT
;
341 end
= (ofs
+ size
- 1) >> PAGE_SHIFT
;
342 /* check page continuity */
343 pg
= sg
->table
[start
].addr
>> PAGE_SHIFT
;
349 if ((sg
->table
[start
].addr
>> PAGE_SHIFT
) != pg
)
350 return (start
<< PAGE_SHIFT
) - ofs
;
352 /* ok, all on continuous pages */
355 EXPORT_SYMBOL(snd_pcm_sgbuf_get_chunk_size
);
356 #endif /* CONFIG_SND_DMA_SGBUF */
359 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
360 * @substream: the substream to allocate the DMA buffer to
361 * @size: the requested buffer size in bytes
363 * Allocates the DMA buffer on the BUS type given earlier to
364 * snd_pcm_lib_preallocate_xxx_pages().
366 * Returns 1 if the buffer is changed, 0 if not changed, or a negative
369 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream
*substream
, size_t size
)
371 struct snd_pcm_runtime
*runtime
;
372 struct snd_dma_buffer
*dmab
= NULL
;
374 if (PCM_RUNTIME_CHECK(substream
))
376 if (snd_BUG_ON(substream
->dma_buffer
.dev
.type
==
377 SNDRV_DMA_TYPE_UNKNOWN
))
379 runtime
= substream
->runtime
;
381 if (runtime
->dma_buffer_p
) {
382 /* perphaps, we might free the large DMA memory region
383 to save some space here, but the actual solution
384 costs us less time */
385 if (runtime
->dma_buffer_p
->bytes
>= size
) {
386 runtime
->dma_bytes
= size
;
387 return 0; /* ok, do not change */
389 snd_pcm_lib_free_pages(substream
);
391 if (substream
->dma_buffer
.area
!= NULL
&&
392 substream
->dma_buffer
.bytes
>= size
) {
393 dmab
= &substream
->dma_buffer
; /* use the pre-allocated buffer */
395 dmab
= kzalloc(sizeof(*dmab
), GFP_KERNEL
);
398 dmab
->dev
= substream
->dma_buffer
.dev
;
399 if (snd_dma_alloc_pages(substream
->dma_buffer
.dev
.type
,
400 substream
->dma_buffer
.dev
.dev
,
406 snd_pcm_set_runtime_buffer(substream
, dmab
);
407 runtime
->dma_bytes
= size
;
408 return 1; /* area was changed */
411 EXPORT_SYMBOL(snd_pcm_lib_malloc_pages
);
414 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
415 * @substream: the substream to release the DMA buffer
417 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
419 * Returns zero if successful, or a negative error code on failure.
421 int snd_pcm_lib_free_pages(struct snd_pcm_substream
*substream
)
423 struct snd_pcm_runtime
*runtime
;
425 if (PCM_RUNTIME_CHECK(substream
))
427 runtime
= substream
->runtime
;
428 if (runtime
->dma_area
== NULL
)
430 if (runtime
->dma_buffer_p
!= &substream
->dma_buffer
) {
431 /* it's a newly allocated buffer. release it now. */
432 snd_dma_free_pages(runtime
->dma_buffer_p
);
433 kfree(runtime
->dma_buffer_p
);
435 snd_pcm_set_runtime_buffer(substream
, NULL
);
439 EXPORT_SYMBOL(snd_pcm_lib_free_pages
);
441 int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream
*substream
,
442 size_t size
, gfp_t gfp_flags
)
444 struct snd_pcm_runtime
*runtime
;
446 if (PCM_RUNTIME_CHECK(substream
))
448 runtime
= substream
->runtime
;
449 if (runtime
->dma_area
) {
450 if (runtime
->dma_bytes
>= size
)
451 return 0; /* already large enough */
452 vfree(runtime
->dma_area
);
454 runtime
->dma_area
= __vmalloc(size
, gfp_flags
, PAGE_KERNEL
);
455 if (!runtime
->dma_area
)
457 runtime
->dma_bytes
= size
;
460 EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer
);
463 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
464 * @substream: the substream with a buffer allocated by
465 * snd_pcm_lib_alloc_vmalloc_buffer()
467 int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream
*substream
)
469 struct snd_pcm_runtime
*runtime
;
471 if (PCM_RUNTIME_CHECK(substream
))
473 runtime
= substream
->runtime
;
474 vfree(runtime
->dma_area
);
475 runtime
->dma_area
= NULL
;
478 EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer
);
481 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
482 * @substream: the substream with a buffer allocated by
483 * snd_pcm_lib_alloc_vmalloc_buffer()
484 * @offset: offset in the buffer
486 * This function is to be used as the page callback in the PCM ops.
488 struct page
*snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream
*substream
,
489 unsigned long offset
)
491 return vmalloc_to_page(substream
->runtime
->dma_area
+ offset
);
493 EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page
);