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;
54 size_t orig_size = size;
58 if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
61 return err; /* fatal error */
65 } while (size >= snd_minimum_buffer);
66 dmab->bytes = 0; /* tell error */
67 pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
68 substream->pcm->card->number, substream->pcm->device,
69 substream->stream ? 'c' : 'p', substream->number,
70 substream->pcm->name, orig_size);
75 * release the preallocated buffer if not yet done.
77 static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
79 if (substream->dma_buffer.area == NULL)
81 snd_dma_free_pages(&substream->dma_buffer);
82 substream->dma_buffer.area = NULL;
86 * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
87 * @substream: the pcm substream instance
89 * Releases the pre-allocated buffer of the given substream.
91 * Return: Zero if successful, or a negative error code on failure.
93 int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
95 snd_pcm_lib_preallocate_dma_free(substream);
100 * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
101 * @pcm: the pcm instance
103 * Releases all the pre-allocated buffers on the given pcm.
105 * Return: Zero if successful, or a negative error code on failure.
107 int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
109 struct snd_pcm_substream *substream;
112 for (stream = 0; stream < 2; stream++)
113 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
114 snd_pcm_lib_preallocate_free(substream);
117 EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
119 #ifdef CONFIG_SND_VERBOSE_PROCFS
121 * read callback for prealloc proc file
123 * prints the current allocated size in kB.
125 static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
126 struct snd_info_buffer *buffer)
128 struct snd_pcm_substream *substream = entry->private_data;
129 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
133 * read callback for prealloc_max proc file
135 * prints the maximum allowed size in kB.
137 static void snd_pcm_lib_preallocate_max_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_max / 1024);
145 * write callback for prealloc proc file
147 * accepts the preallocation size in kB.
149 static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
150 struct snd_info_buffer *buffer)
152 struct snd_pcm_substream *substream = entry->private_data;
153 char line[64], str[64];
155 struct snd_dma_buffer new_dmab;
157 if (substream->runtime) {
158 buffer->error = -EBUSY;
161 if (!snd_info_get_line(buffer, line, sizeof(line))) {
162 snd_info_get_str(str, line, sizeof(str));
163 size = simple_strtoul(str, NULL, 10) * 1024;
164 if ((size != 0 && size < 8192) || size > substream->dma_max) {
165 buffer->error = -EINVAL;
168 if (substream->dma_buffer.bytes == size)
170 memset(&new_dmab, 0, sizeof(new_dmab));
171 new_dmab.dev = substream->dma_buffer.dev;
173 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
174 substream->dma_buffer.dev.dev,
175 size, &new_dmab) < 0) {
176 buffer->error = -ENOMEM;
179 substream->buffer_bytes_max = size;
181 substream->buffer_bytes_max = UINT_MAX;
183 if (substream->dma_buffer.area)
184 snd_dma_free_pages(&substream->dma_buffer);
185 substream->dma_buffer = new_dmab;
187 buffer->error = -EINVAL;
191 static inline void preallocate_info_init(struct snd_pcm_substream *substream)
193 struct snd_info_entry *entry;
195 entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
196 substream->proc_root);
198 snd_info_set_text_ops(entry, substream,
199 snd_pcm_lib_preallocate_proc_read);
200 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
203 entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
204 substream->proc_root);
206 snd_info_set_text_ops(entry, substream,
207 snd_pcm_lib_preallocate_max_proc_read);
210 #else /* !CONFIG_SND_VERBOSE_PROCFS */
211 #define preallocate_info_init(s)
212 #endif /* CONFIG_SND_VERBOSE_PROCFS */
215 * pre-allocate the buffer and create a proc file for the substream
217 static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
218 size_t size, size_t max)
221 if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
222 preallocate_pcm_pages(substream, size);
224 if (substream->dma_buffer.bytes > 0)
225 substream->buffer_bytes_max = substream->dma_buffer.bytes;
226 substream->dma_max = max;
227 preallocate_info_init(substream);
233 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
234 * @substream: the pcm substream instance
235 * @type: DMA type (SNDRV_DMA_TYPE_*)
236 * @data: DMA type dependent data
237 * @size: the requested pre-allocation size in bytes
238 * @max: the max. allowed pre-allocation size
240 * Do pre-allocation for the given DMA buffer type.
242 * Return: Zero if successful, or a negative error code on failure.
244 int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
245 int type, struct device *data,
246 size_t size, size_t max)
248 substream->dma_buffer.dev.type = type;
249 substream->dma_buffer.dev.dev = data;
250 return snd_pcm_lib_preallocate_pages1(substream, size, max);
252 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
255 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
256 * @pcm: the pcm instance
257 * @type: DMA type (SNDRV_DMA_TYPE_*)
258 * @data: DMA type dependent data
259 * @size: the requested pre-allocation size in bytes
260 * @max: the max. allowed pre-allocation size
262 * Do pre-allocation to all substreams of the given pcm for the
263 * specified DMA type.
265 * Return: Zero if successful, or a negative error code on failure.
267 int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
268 int type, void *data,
269 size_t size, size_t max)
271 struct snd_pcm_substream *substream;
274 for (stream = 0; stream < 2; stream++)
275 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
276 if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
280 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
282 #ifdef CONFIG_SND_DMA_SGBUF
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 * Used as the page callback of PCM ops.
290 * Return: The page struct at the given buffer offset. %NULL on failure.
292 struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
294 struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
296 unsigned int idx = offset >> PAGE_SHIFT;
297 if (idx >= (unsigned int)sgbuf->pages)
299 return sgbuf->page_table[idx];
301 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
302 #endif /* CONFIG_SND_DMA_SGBUF */
305 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
306 * @substream: the substream to allocate the DMA buffer to
307 * @size: the requested buffer size in bytes
309 * Allocates the DMA buffer on the BUS type given earlier to
310 * snd_pcm_lib_preallocate_xxx_pages().
312 * Return: 1 if the buffer is changed, 0 if not changed, or a negative
315 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
317 struct snd_pcm_runtime *runtime;
318 struct snd_dma_buffer *dmab = NULL;
320 if (PCM_RUNTIME_CHECK(substream))
322 if (snd_BUG_ON(substream->dma_buffer.dev.type ==
323 SNDRV_DMA_TYPE_UNKNOWN))
325 runtime = substream->runtime;
327 if (runtime->dma_buffer_p) {
328 /* perphaps, we might free the large DMA memory region
329 to save some space here, but the actual solution
330 costs us less time */
331 if (runtime->dma_buffer_p->bytes >= size) {
332 runtime->dma_bytes = size;
333 return 0; /* ok, do not change */
335 snd_pcm_lib_free_pages(substream);
337 if (substream->dma_buffer.area != NULL &&
338 substream->dma_buffer.bytes >= size) {
339 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
341 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
344 dmab->dev = substream->dma_buffer.dev;
345 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
346 substream->dma_buffer.dev.dev,
352 snd_pcm_set_runtime_buffer(substream, dmab);
353 runtime->dma_bytes = size;
354 return 1; /* area was changed */
356 EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
359 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
360 * @substream: the substream to release the DMA buffer
362 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
364 * Return: Zero if successful, or a negative error code on failure.
366 int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
368 struct snd_pcm_runtime *runtime;
370 if (PCM_RUNTIME_CHECK(substream))
372 runtime = substream->runtime;
373 if (runtime->dma_area == NULL)
375 if (runtime->dma_buffer_p != &substream->dma_buffer) {
376 /* it's a newly allocated buffer. release it now. */
377 snd_dma_free_pages(runtime->dma_buffer_p);
378 kfree(runtime->dma_buffer_p);
380 snd_pcm_set_runtime_buffer(substream, NULL);
383 EXPORT_SYMBOL(snd_pcm_lib_free_pages);
385 int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
386 size_t size, gfp_t gfp_flags)
388 struct snd_pcm_runtime *runtime;
390 if (PCM_RUNTIME_CHECK(substream))
392 runtime = substream->runtime;
393 if (runtime->dma_area) {
394 if (runtime->dma_bytes >= size)
395 return 0; /* already large enough */
396 vfree(runtime->dma_area);
398 runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
399 if (!runtime->dma_area)
401 runtime->dma_bytes = size;
404 EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
407 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
408 * @substream: the substream with a buffer allocated by
409 * snd_pcm_lib_alloc_vmalloc_buffer()
411 * Return: Zero if successful, or a negative error code on failure.
413 int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
415 struct snd_pcm_runtime *runtime;
417 if (PCM_RUNTIME_CHECK(substream))
419 runtime = substream->runtime;
420 vfree(runtime->dma_area);
421 runtime->dma_area = NULL;
424 EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
427 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
428 * @substream: the substream with a buffer allocated by
429 * snd_pcm_lib_alloc_vmalloc_buffer()
430 * @offset: offset in the buffer
432 * This function is to be used as the page callback in the PCM ops.
434 * Return: The page struct, or %NULL on failure.
436 struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
437 unsigned long offset)
439 return vmalloc_to_page(substream->runtime->dma_area + offset);
441 EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);