2 * Digital Audio (PCM) abstract layer
3 * Copyright (c) by Jaroslav Kysela <perex@suse.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
22 #include <sound/driver.h>
24 #include <linux/time.h>
25 #include <linux/init.h>
26 #include <linux/moduleparam.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 snd_assert(size
> 0, return -EINVAL
);
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_unregister(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 #ifdef CONFIG_SND_VERBOSE_PROCFS
131 * read callback for prealloc proc file
133 * prints the current allocated size in kB.
135 static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry
*entry
,
136 struct snd_info_buffer
*buffer
)
138 struct snd_pcm_substream
*substream
= entry
->private_data
;
139 snd_iprintf(buffer
, "%lu\n", (unsigned long) substream
->dma_buffer
.bytes
/ 1024);
143 * write callback for prealloc proc file
145 * accepts the preallocation size in kB.
147 static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry
*entry
,
148 struct snd_info_buffer
*buffer
)
150 struct snd_pcm_substream
*substream
= entry
->private_data
;
151 char line
[64], str
[64];
153 struct snd_dma_buffer new_dmab
;
155 if (substream
->runtime
) {
156 buffer
->error
= -EBUSY
;
159 if (!snd_info_get_line(buffer
, line
, sizeof(line
))) {
160 snd_info_get_str(str
, line
, sizeof(str
));
161 size
= simple_strtoul(str
, NULL
, 10) * 1024;
162 if ((size
!= 0 && size
< 8192) || size
> substream
->dma_max
) {
163 buffer
->error
= -EINVAL
;
166 if (substream
->dma_buffer
.bytes
== size
)
168 memset(&new_dmab
, 0, sizeof(new_dmab
));
169 new_dmab
.dev
= substream
->dma_buffer
.dev
;
171 if (snd_dma_alloc_pages(substream
->dma_buffer
.dev
.type
,
172 substream
->dma_buffer
.dev
.dev
,
173 size
, &new_dmab
) < 0) {
174 buffer
->error
= -ENOMEM
;
177 substream
->buffer_bytes_max
= size
;
179 substream
->buffer_bytes_max
= UINT_MAX
;
181 if (substream
->dma_buffer
.area
)
182 snd_dma_free_pages(&substream
->dma_buffer
);
183 substream
->dma_buffer
= new_dmab
;
185 buffer
->error
= -EINVAL
;
189 static inline void preallocate_info_init(struct snd_pcm_substream
*substream
)
191 struct snd_info_entry
*entry
;
193 if ((entry
= snd_info_create_card_entry(substream
->pcm
->card
, "prealloc", substream
->proc_root
)) != NULL
) {
194 entry
->c
.text
.read_size
= 64;
195 entry
->c
.text
.read
= snd_pcm_lib_preallocate_proc_read
;
196 entry
->c
.text
.write_size
= 64;
197 entry
->c
.text
.write
= snd_pcm_lib_preallocate_proc_write
;
198 entry
->mode
|= S_IWUSR
;
199 entry
->private_data
= substream
;
200 if (snd_info_register(entry
) < 0) {
201 snd_info_free_entry(entry
);
205 substream
->proc_prealloc_entry
= entry
;
208 #else /* !CONFIG_SND_VERBOSE_PROCFS */
209 #define preallocate_info_init(s)
210 #endif /* CONFIG_SND_VERBOSE_PROCFS */
213 * pre-allocate the buffer and create a proc file for the substream
215 static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream
*substream
,
216 size_t size
, size_t max
)
219 if (size
> 0 && preallocate_dma
&& substream
->number
< maximum_substreams
)
220 preallocate_pcm_pages(substream
, size
);
222 if (substream
->dma_buffer
.bytes
> 0)
223 substream
->buffer_bytes_max
= substream
->dma_buffer
.bytes
;
224 substream
->dma_max
= max
;
225 preallocate_info_init(substream
);
231 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
232 * @substream: the pcm substream instance
233 * @type: DMA type (SNDRV_DMA_TYPE_*)
234 * @data: DMA type dependant data
235 * @size: the requested pre-allocation size in bytes
236 * @max: the max. allowed pre-allocation size
238 * Do pre-allocation for the given DMA buffer type.
240 * When substream->dma_buf_id is set, the function tries to look for
241 * the reserved buffer, and the buffer is not freed but reserved at
242 * destruction time. The dma_buf_id must be unique for all systems
243 * (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id().
245 * Returns zero if successful, or a negative error code on failure.
247 int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream
*substream
,
248 int type
, struct device
*data
,
249 size_t size
, size_t max
)
251 substream
->dma_buffer
.dev
.type
= type
;
252 substream
->dma_buffer
.dev
.dev
= data
;
253 return snd_pcm_lib_preallocate_pages1(substream
, size
, max
);
257 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continous memory type (all substreams)
258 * @pcm: the pcm instance
259 * @type: DMA type (SNDRV_DMA_TYPE_*)
260 * @data: DMA type dependant data
261 * @size: the requested pre-allocation size in bytes
262 * @max: the max. allowed pre-allocation size
264 * Do pre-allocation to all substreams of the given pcm for the
265 * specified DMA type.
267 * Returns zero if successful, or a negative error code on failure.
269 int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm
*pcm
,
270 int type
, void *data
,
271 size_t size
, size_t max
)
273 struct snd_pcm_substream
*substream
;
276 for (stream
= 0; stream
< 2; stream
++)
277 for (substream
= pcm
->streams
[stream
].substream
; substream
; substream
= substream
->next
)
278 if ((err
= snd_pcm_lib_preallocate_pages(substream
, type
, data
, size
, max
)) < 0)
284 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
285 * @substream: the pcm substream instance
286 * @offset: the buffer offset
288 * Returns the page struct at the given buffer offset.
289 * Used as the page callback of PCM ops.
291 struct page
*snd_pcm_sgbuf_ops_page(struct snd_pcm_substream
*substream
, unsigned long offset
)
293 struct snd_sg_buf
*sgbuf
= snd_pcm_substream_sgbuf(substream
);
295 unsigned int idx
= offset
>> PAGE_SHIFT
;
296 if (idx
>= (unsigned int)sgbuf
->pages
)
298 return sgbuf
->page_table
[idx
];
302 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
303 * @substream: the substream to allocate the DMA buffer to
304 * @size: the requested buffer size in bytes
306 * Allocates the DMA buffer on the BUS type given earlier to
307 * snd_pcm_lib_preallocate_xxx_pages().
309 * Returns 1 if the buffer is changed, 0 if not changed, or a negative
312 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream
*substream
, size_t size
)
314 struct snd_pcm_runtime
*runtime
;
315 struct snd_dma_buffer
*dmab
= NULL
;
317 snd_assert(substream
->dma_buffer
.dev
.type
!= SNDRV_DMA_TYPE_UNKNOWN
, return -EINVAL
);
318 snd_assert(substream
!= NULL
, return -EINVAL
);
319 runtime
= substream
->runtime
;
320 snd_assert(runtime
!= NULL
, return -EINVAL
);
322 if (runtime
->dma_buffer_p
) {
323 /* perphaps, we might free the large DMA memory region
324 to save some space here, but the actual solution
325 costs us less time */
326 if (runtime
->dma_buffer_p
->bytes
>= size
) {
327 runtime
->dma_bytes
= size
;
328 return 0; /* ok, do not change */
330 snd_pcm_lib_free_pages(substream
);
332 if (substream
->dma_buffer
.area
!= NULL
&&
333 substream
->dma_buffer
.bytes
>= size
) {
334 dmab
= &substream
->dma_buffer
; /* use the pre-allocated buffer */
336 dmab
= kzalloc(sizeof(*dmab
), GFP_KERNEL
);
339 dmab
->dev
= substream
->dma_buffer
.dev
;
340 if (snd_dma_alloc_pages(substream
->dma_buffer
.dev
.type
,
341 substream
->dma_buffer
.dev
.dev
,
347 snd_pcm_set_runtime_buffer(substream
, dmab
);
348 runtime
->dma_bytes
= size
;
349 return 1; /* area was changed */
353 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
354 * @substream: the substream to release the DMA buffer
356 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
358 * Returns zero if successful, or a negative error code on failure.
360 int snd_pcm_lib_free_pages(struct snd_pcm_substream
*substream
)
362 struct snd_pcm_runtime
*runtime
;
364 snd_assert(substream
!= NULL
, return -EINVAL
);
365 runtime
= substream
->runtime
;
366 snd_assert(runtime
!= NULL
, return -EINVAL
);
367 if (runtime
->dma_area
== NULL
)
369 if (runtime
->dma_buffer_p
!= &substream
->dma_buffer
) {
370 /* it's a newly allocated buffer. release it now. */
371 snd_dma_free_pages(runtime
->dma_buffer_p
);
372 kfree(runtime
->dma_buffer_p
);
374 snd_pcm_set_runtime_buffer(substream
, NULL
);