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 if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
196 entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
197 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
199 entry->private_data = substream;
200 if (snd_info_register(entry) < 0)
201 snd_info_free_entry(entry);
203 if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
204 entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
205 entry->private_data = substream;
206 if (snd_info_register(entry) < 0)
207 snd_info_free_entry(entry);
211 #else /* !CONFIG_SND_VERBOSE_PROCFS */
212 #define preallocate_info_init(s)
213 #endif /* CONFIG_SND_VERBOSE_PROCFS */
216 * pre-allocate the buffer and create a proc file for the substream
218 static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
219 size_t size, size_t max)
222 if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
223 preallocate_pcm_pages(substream, size);
225 if (substream->dma_buffer.bytes > 0)
226 substream->buffer_bytes_max = substream->dma_buffer.bytes;
227 substream->dma_max = max;
228 preallocate_info_init(substream);
234 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
235 * @substream: the pcm substream instance
236 * @type: DMA type (SNDRV_DMA_TYPE_*)
237 * @data: DMA type dependent data
238 * @size: the requested pre-allocation size in bytes
239 * @max: the max. allowed pre-allocation size
241 * Do pre-allocation for the given DMA buffer type.
243 * Return: Zero if successful, or a negative error code on failure.
245 int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
246 int type, struct device *data,
247 size_t size, size_t max)
249 substream->dma_buffer.dev.type = type;
250 substream->dma_buffer.dev.dev = data;
251 return snd_pcm_lib_preallocate_pages1(substream, size, max);
253 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
256 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
257 * @pcm: the pcm instance
258 * @type: DMA type (SNDRV_DMA_TYPE_*)
259 * @data: DMA type dependent data
260 * @size: the requested pre-allocation size in bytes
261 * @max: the max. allowed pre-allocation size
263 * Do pre-allocation to all substreams of the given pcm for the
264 * specified DMA type.
266 * Return: Zero if successful, or a negative error code on failure.
268 int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
269 int type, void *data,
270 size_t size, size_t max)
272 struct snd_pcm_substream *substream;
275 for (stream = 0; stream < 2; stream++)
276 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
277 if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
281 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
283 #ifdef CONFIG_SND_DMA_SGBUF
285 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
286 * @substream: the pcm substream instance
287 * @offset: the buffer offset
289 * Used as the page callback of PCM ops.
291 * Return: The page struct at the given buffer offset. %NULL on failure.
293 struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
295 struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
297 unsigned int idx = offset >> PAGE_SHIFT;
298 if (idx >= (unsigned int)sgbuf->pages)
300 return sgbuf->page_table[idx];
302 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
303 #endif /* CONFIG_SND_DMA_SGBUF */
306 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
307 * @substream: the substream to allocate the DMA buffer to
308 * @size: the requested buffer size in bytes
310 * Allocates the DMA buffer on the BUS type given earlier to
311 * snd_pcm_lib_preallocate_xxx_pages().
313 * Return: 1 if the buffer is changed, 0 if not changed, or a negative
316 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
318 struct snd_pcm_runtime *runtime;
319 struct snd_dma_buffer *dmab = NULL;
321 if (PCM_RUNTIME_CHECK(substream))
323 if (snd_BUG_ON(substream->dma_buffer.dev.type ==
324 SNDRV_DMA_TYPE_UNKNOWN))
326 runtime = substream->runtime;
328 if (runtime->dma_buffer_p) {
329 /* perphaps, we might free the large DMA memory region
330 to save some space here, but the actual solution
331 costs us less time */
332 if (runtime->dma_buffer_p->bytes >= size) {
333 runtime->dma_bytes = size;
334 return 0; /* ok, do not change */
336 snd_pcm_lib_free_pages(substream);
338 if (substream->dma_buffer.area != NULL &&
339 substream->dma_buffer.bytes >= size) {
340 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
342 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
345 dmab->dev = substream->dma_buffer.dev;
346 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
347 substream->dma_buffer.dev.dev,
353 snd_pcm_set_runtime_buffer(substream, dmab);
354 runtime->dma_bytes = size;
355 return 1; /* area was changed */
357 EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
360 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
361 * @substream: the substream to release the DMA buffer
363 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
365 * Return: Zero if successful, or a negative error code on failure.
367 int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
369 struct snd_pcm_runtime *runtime;
371 if (PCM_RUNTIME_CHECK(substream))
373 runtime = substream->runtime;
374 if (runtime->dma_area == NULL)
376 if (runtime->dma_buffer_p != &substream->dma_buffer) {
377 /* it's a newly allocated buffer. release it now. */
378 snd_dma_free_pages(runtime->dma_buffer_p);
379 kfree(runtime->dma_buffer_p);
381 snd_pcm_set_runtime_buffer(substream, NULL);
384 EXPORT_SYMBOL(snd_pcm_lib_free_pages);
386 int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
387 size_t size, gfp_t gfp_flags)
389 struct snd_pcm_runtime *runtime;
391 if (PCM_RUNTIME_CHECK(substream))
393 runtime = substream->runtime;
394 if (runtime->dma_area) {
395 if (runtime->dma_bytes >= size)
396 return 0; /* already large enough */
397 vfree(runtime->dma_area);
399 runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
400 if (!runtime->dma_area)
402 runtime->dma_bytes = size;
405 EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
408 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
409 * @substream: the substream with a buffer allocated by
410 * snd_pcm_lib_alloc_vmalloc_buffer()
412 * Return: Zero if successful, or a negative error code on failure.
414 int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
416 struct snd_pcm_runtime *runtime;
418 if (PCM_RUNTIME_CHECK(substream))
420 runtime = substream->runtime;
421 vfree(runtime->dma_area);
422 runtime->dma_area = NULL;
425 EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
428 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
429 * @substream: the substream with a buffer allocated by
430 * snd_pcm_lib_alloc_vmalloc_buffer()
431 * @offset: offset in the buffer
433 * This function is to be used as the page callback in the PCM ops.
435 * Return: The page struct, or %NULL on failure.
437 struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
438 unsigned long offset)
440 return vmalloc_to_page(substream->runtime->dma_area + offset);
442 EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);