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/moduleparam.h>
26 #include <linux/vmalloc.h>
27 #include <sound/core.h>
28 #include <sound/pcm.h>
29 #include <sound/info.h>
30 #include <sound/initval.h>
32 static int preallocate_dma
= 1;
33 module_param(preallocate_dma
, int, 0444);
34 MODULE_PARM_DESC(preallocate_dma
, "Preallocate DMA memory when the PCM devices are initialized.");
36 static int maximum_substreams
= 4;
37 module_param(maximum_substreams
, int, 0444);
38 MODULE_PARM_DESC(maximum_substreams
, "Maximum substreams with preallocated DMA memory.");
40 static const size_t snd_minimum_buffer
= 16384;
44 * try to allocate as the large pages as possible.
45 * stores the resultant memory size in *res_size.
47 * the minimum size is snd_minimum_buffer. it should be power of 2.
49 static int preallocate_pcm_pages(struct snd_pcm_substream
*substream
, size_t size
)
51 struct snd_dma_buffer
*dmab
= &substream
->dma_buffer
;
54 /* already reserved? */
55 if (snd_dma_get_reserved_buf(dmab
, substream
->dma_buf_id
) > 0) {
56 if (dmab
->bytes
>= size
)
58 /* no, free the reserved block */
59 snd_dma_free_pages(dmab
);
64 if ((err
= snd_dma_alloc_pages(dmab
->dev
.type
, dmab
->dev
.dev
,
67 return err
; /* fatal error */
71 } while (size
>= snd_minimum_buffer
);
72 dmab
->bytes
= 0; /* tell error */
77 * release the preallocated buffer if not yet done.
79 static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream
*substream
)
81 if (substream
->dma_buffer
.area
== NULL
)
83 if (substream
->dma_buf_id
)
84 snd_dma_reserve_buf(&substream
->dma_buffer
, substream
->dma_buf_id
);
86 snd_dma_free_pages(&substream
->dma_buffer
);
87 substream
->dma_buffer
.area
= NULL
;
91 * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
92 * @substream: the pcm substream instance
94 * Releases the pre-allocated buffer of the given substream.
96 * Returns zero if successful, or a negative error code on failure.
98 int snd_pcm_lib_preallocate_free(struct snd_pcm_substream
*substream
)
100 snd_pcm_lib_preallocate_dma_free(substream
);
101 #ifdef CONFIG_SND_VERBOSE_PROCFS
102 snd_info_free_entry(substream
->proc_prealloc_max_entry
);
103 substream
->proc_prealloc_max_entry
= NULL
;
104 snd_info_free_entry(substream
->proc_prealloc_entry
);
105 substream
->proc_prealloc_entry
= NULL
;
111 * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
112 * @pcm: the pcm instance
114 * Releases all the pre-allocated buffers on the given pcm.
116 * Returns zero if successful, or a negative error code on failure.
118 int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm
*pcm
)
120 struct snd_pcm_substream
*substream
;
123 for (stream
= 0; stream
< 2; stream
++)
124 for (substream
= pcm
->streams
[stream
].substream
; substream
; substream
= substream
->next
)
125 snd_pcm_lib_preallocate_free(substream
);
129 EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all
);
131 #ifdef CONFIG_SND_VERBOSE_PROCFS
133 * read callback for prealloc proc file
135 * prints the current allocated size in kB.
137 static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry
*entry
,
138 struct snd_info_buffer
*buffer
)
140 struct snd_pcm_substream
*substream
= entry
->private_data
;
141 snd_iprintf(buffer
, "%lu\n", (unsigned long) substream
->dma_buffer
.bytes
/ 1024);
145 * read callback for prealloc_max proc file
147 * prints the maximum allowed size in kB.
149 static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry
*entry
,
150 struct snd_info_buffer
*buffer
)
152 struct snd_pcm_substream
*substream
= entry
->private_data
;
153 snd_iprintf(buffer
, "%lu\n", (unsigned long) substream
->dma_max
/ 1024);
157 * write callback for prealloc proc file
159 * accepts the preallocation size in kB.
161 static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry
*entry
,
162 struct snd_info_buffer
*buffer
)
164 struct snd_pcm_substream
*substream
= entry
->private_data
;
165 char line
[64], str
[64];
167 struct snd_dma_buffer new_dmab
;
169 if (substream
->runtime
) {
170 buffer
->error
= -EBUSY
;
173 if (!snd_info_get_line(buffer
, line
, sizeof(line
))) {
174 snd_info_get_str(str
, line
, sizeof(str
));
175 size
= simple_strtoul(str
, NULL
, 10) * 1024;
176 if ((size
!= 0 && size
< 8192) || size
> substream
->dma_max
) {
177 buffer
->error
= -EINVAL
;
180 if (substream
->dma_buffer
.bytes
== size
)
182 memset(&new_dmab
, 0, sizeof(new_dmab
));
183 new_dmab
.dev
= substream
->dma_buffer
.dev
;
185 if (snd_dma_alloc_pages(substream
->dma_buffer
.dev
.type
,
186 substream
->dma_buffer
.dev
.dev
,
187 size
, &new_dmab
) < 0) {
188 buffer
->error
= -ENOMEM
;
191 substream
->buffer_bytes_max
= size
;
193 substream
->buffer_bytes_max
= UINT_MAX
;
195 if (substream
->dma_buffer
.area
)
196 snd_dma_free_pages(&substream
->dma_buffer
);
197 substream
->dma_buffer
= new_dmab
;
199 buffer
->error
= -EINVAL
;
203 static inline void preallocate_info_init(struct snd_pcm_substream
*substream
)
205 struct snd_info_entry
*entry
;
207 if ((entry
= snd_info_create_card_entry(substream
->pcm
->card
, "prealloc", substream
->proc_root
)) != NULL
) {
208 entry
->c
.text
.read
= snd_pcm_lib_preallocate_proc_read
;
209 entry
->c
.text
.write
= snd_pcm_lib_preallocate_proc_write
;
210 entry
->mode
|= S_IWUSR
;
211 entry
->private_data
= substream
;
212 if (snd_info_register(entry
) < 0) {
213 snd_info_free_entry(entry
);
217 substream
->proc_prealloc_entry
= entry
;
218 if ((entry
= snd_info_create_card_entry(substream
->pcm
->card
, "prealloc_max", substream
->proc_root
)) != NULL
) {
219 entry
->c
.text
.read
= snd_pcm_lib_preallocate_max_proc_read
;
220 entry
->private_data
= substream
;
221 if (snd_info_register(entry
) < 0) {
222 snd_info_free_entry(entry
);
226 substream
->proc_prealloc_max_entry
= entry
;
229 #else /* !CONFIG_SND_VERBOSE_PROCFS */
230 #define preallocate_info_init(s)
231 #endif /* CONFIG_SND_VERBOSE_PROCFS */
234 * pre-allocate the buffer and create a proc file for the substream
236 static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream
*substream
,
237 size_t size
, size_t max
)
240 if (size
> 0 && preallocate_dma
&& substream
->number
< maximum_substreams
)
241 preallocate_pcm_pages(substream
, size
);
243 if (substream
->dma_buffer
.bytes
> 0)
244 substream
->buffer_bytes_max
= substream
->dma_buffer
.bytes
;
245 substream
->dma_max
= max
;
246 preallocate_info_init(substream
);
252 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
253 * @substream: the pcm substream instance
254 * @type: DMA type (SNDRV_DMA_TYPE_*)
255 * @data: DMA type dependant data
256 * @size: the requested pre-allocation size in bytes
257 * @max: the max. allowed pre-allocation size
259 * Do pre-allocation for the given DMA buffer type.
261 * When substream->dma_buf_id is set, the function tries to look for
262 * the reserved buffer, and the buffer is not freed but reserved at
263 * destruction time. The dma_buf_id must be unique for all systems
264 * (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id().
266 * Returns zero if successful, or a negative error code on failure.
268 int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream
*substream
,
269 int type
, struct device
*data
,
270 size_t size
, size_t max
)
272 substream
->dma_buffer
.dev
.type
= type
;
273 substream
->dma_buffer
.dev
.dev
= data
;
274 return snd_pcm_lib_preallocate_pages1(substream
, size
, max
);
277 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages
);
280 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continous memory type (all substreams)
281 * @pcm: the pcm instance
282 * @type: DMA type (SNDRV_DMA_TYPE_*)
283 * @data: DMA type dependant data
284 * @size: the requested pre-allocation size in bytes
285 * @max: the max. allowed pre-allocation size
287 * Do pre-allocation to all substreams of the given pcm for the
288 * specified DMA type.
290 * Returns zero if successful, or a negative error code on failure.
292 int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm
*pcm
,
293 int type
, void *data
,
294 size_t size
, size_t max
)
296 struct snd_pcm_substream
*substream
;
299 for (stream
= 0; stream
< 2; stream
++)
300 for (substream
= pcm
->streams
[stream
].substream
; substream
; substream
= substream
->next
)
301 if ((err
= snd_pcm_lib_preallocate_pages(substream
, type
, data
, size
, max
)) < 0)
306 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all
);
308 #ifdef CONFIG_SND_DMA_SGBUF
310 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
311 * @substream: the pcm substream instance
312 * @offset: the buffer offset
314 * Returns the page struct at the given buffer offset.
315 * Used as the page callback of PCM ops.
317 struct page
*snd_pcm_sgbuf_ops_page(struct snd_pcm_substream
*substream
, unsigned long offset
)
319 struct snd_sg_buf
*sgbuf
= snd_pcm_substream_sgbuf(substream
);
321 unsigned int idx
= offset
>> PAGE_SHIFT
;
322 if (idx
>= (unsigned int)sgbuf
->pages
)
324 return sgbuf
->page_table
[idx
];
327 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page
);
330 * compute the max chunk size with continuous pages on sg-buffer
332 unsigned int snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream
*substream
,
333 unsigned int ofs
, unsigned int size
)
335 struct snd_sg_buf
*sg
= snd_pcm_substream_sgbuf(substream
);
336 unsigned int start
, end
, pg
;
338 start
= ofs
>> PAGE_SHIFT
;
339 end
= (ofs
+ size
- 1) >> PAGE_SHIFT
;
340 /* check page continuity */
341 pg
= sg
->table
[start
].addr
>> PAGE_SHIFT
;
347 if ((sg
->table
[start
].addr
>> PAGE_SHIFT
) != pg
)
348 return (start
<< PAGE_SHIFT
) - ofs
;
350 /* ok, all on continuous pages */
353 EXPORT_SYMBOL(snd_pcm_sgbuf_get_chunk_size
);
354 #endif /* CONFIG_SND_DMA_SGBUF */
357 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
358 * @substream: the substream to allocate the DMA buffer to
359 * @size: the requested buffer size in bytes
361 * Allocates the DMA buffer on the BUS type given earlier to
362 * snd_pcm_lib_preallocate_xxx_pages().
364 * Returns 1 if the buffer is changed, 0 if not changed, or a negative
367 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream
*substream
, size_t size
)
369 struct snd_pcm_runtime
*runtime
;
370 struct snd_dma_buffer
*dmab
= NULL
;
372 if (PCM_RUNTIME_CHECK(substream
))
374 if (snd_BUG_ON(substream
->dma_buffer
.dev
.type
==
375 SNDRV_DMA_TYPE_UNKNOWN
))
377 runtime
= substream
->runtime
;
379 if (runtime
->dma_buffer_p
) {
380 /* perphaps, we might free the large DMA memory region
381 to save some space here, but the actual solution
382 costs us less time */
383 if (runtime
->dma_buffer_p
->bytes
>= size
) {
384 runtime
->dma_bytes
= size
;
385 return 0; /* ok, do not change */
387 snd_pcm_lib_free_pages(substream
);
389 if (substream
->dma_buffer
.area
!= NULL
&&
390 substream
->dma_buffer
.bytes
>= size
) {
391 dmab
= &substream
->dma_buffer
; /* use the pre-allocated buffer */
393 dmab
= kzalloc(sizeof(*dmab
), GFP_KERNEL
);
396 dmab
->dev
= substream
->dma_buffer
.dev
;
397 if (snd_dma_alloc_pages(substream
->dma_buffer
.dev
.type
,
398 substream
->dma_buffer
.dev
.dev
,
404 snd_pcm_set_runtime_buffer(substream
, dmab
);
405 runtime
->dma_bytes
= size
;
406 return 1; /* area was changed */
409 EXPORT_SYMBOL(snd_pcm_lib_malloc_pages
);
412 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
413 * @substream: the substream to release the DMA buffer
415 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
417 * Returns zero if successful, or a negative error code on failure.
419 int snd_pcm_lib_free_pages(struct snd_pcm_substream
*substream
)
421 struct snd_pcm_runtime
*runtime
;
423 if (PCM_RUNTIME_CHECK(substream
))
425 runtime
= substream
->runtime
;
426 if (runtime
->dma_area
== NULL
)
428 if (runtime
->dma_buffer_p
!= &substream
->dma_buffer
) {
429 /* it's a newly allocated buffer. release it now. */
430 snd_dma_free_pages(runtime
->dma_buffer_p
);
431 kfree(runtime
->dma_buffer_p
);
433 snd_pcm_set_runtime_buffer(substream
, NULL
);
437 EXPORT_SYMBOL(snd_pcm_lib_free_pages
);
439 int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream
*substream
,
440 size_t size
, gfp_t gfp_flags
)
442 struct snd_pcm_runtime
*runtime
;
444 if (PCM_RUNTIME_CHECK(substream
))
446 runtime
= substream
->runtime
;
447 if (runtime
->dma_area
) {
448 if (runtime
->dma_bytes
>= size
)
449 return 0; /* already large enough */
450 vfree(runtime
->dma_area
);
452 runtime
->dma_area
= __vmalloc(size
, gfp_flags
, PAGE_KERNEL
);
453 if (!runtime
->dma_area
)
455 runtime
->dma_bytes
= size
;
458 EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer
);
461 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
462 * @substream: the substream with a buffer allocated by
463 * snd_pcm_lib_alloc_vmalloc_buffer()
465 int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream
*substream
)
467 struct snd_pcm_runtime
*runtime
;
469 if (PCM_RUNTIME_CHECK(substream
))
471 runtime
= substream
->runtime
;
472 vfree(runtime
->dma_area
);
473 runtime
->dma_area
= NULL
;
476 EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer
);
479 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
480 * @substream: the substream with a buffer allocated by
481 * snd_pcm_lib_alloc_vmalloc_buffer()
482 * @offset: offset in the buffer
484 * This function is to be used as the page callback in the PCM ops.
486 struct page
*snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream
*substream
,
487 unsigned long offset
)
489 return vmalloc_to_page(substream
->runtime
->dma_area
+ offset
);
491 EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page
);