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);
96 #ifdef CONFIG_SND_VERBOSE_PROCFS
97 snd_info_free_entry(substream->proc_prealloc_max_entry);
98 substream->proc_prealloc_max_entry = NULL;
99 snd_info_free_entry(substream->proc_prealloc_entry);
100 substream->proc_prealloc_entry = NULL;
106 * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
107 * @pcm: the pcm instance
109 * Releases all the pre-allocated buffers on the given pcm.
111 * Return: Zero if successful, or a negative error code on failure.
113 int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
115 struct snd_pcm_substream *substream;
118 for (stream = 0; stream < 2; stream++)
119 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
120 snd_pcm_lib_preallocate_free(substream);
123 EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
125 #ifdef CONFIG_SND_VERBOSE_PROCFS
127 * read callback for prealloc proc file
129 * prints the current allocated size in kB.
131 static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
132 struct snd_info_buffer *buffer)
134 struct snd_pcm_substream *substream = entry->private_data;
135 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
139 * read callback for prealloc_max proc file
141 * prints the maximum allowed size in kB.
143 static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
144 struct snd_info_buffer *buffer)
146 struct snd_pcm_substream *substream = entry->private_data;
147 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
151 * write callback for prealloc proc file
153 * accepts the preallocation size in kB.
155 static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
156 struct snd_info_buffer *buffer)
158 struct snd_pcm_substream *substream = entry->private_data;
159 char line[64], str[64];
161 struct snd_dma_buffer new_dmab;
163 mutex_lock(&substream->pcm->open_mutex);
164 if (substream->runtime) {
165 buffer->error = -EBUSY;
168 if (!snd_info_get_line(buffer, line, sizeof(line))) {
169 snd_info_get_str(str, line, sizeof(str));
170 size = simple_strtoul(str, NULL, 10) * 1024;
171 if ((size != 0 && size < 8192) || size > substream->dma_max) {
172 buffer->error = -EINVAL;
175 if (substream->dma_buffer.bytes == size)
177 memset(&new_dmab, 0, sizeof(new_dmab));
178 new_dmab.dev = substream->dma_buffer.dev;
180 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
181 substream->dma_buffer.dev.dev,
182 size, &new_dmab) < 0) {
183 buffer->error = -ENOMEM;
186 substream->buffer_bytes_max = size;
188 substream->buffer_bytes_max = UINT_MAX;
190 if (substream->dma_buffer.area)
191 snd_dma_free_pages(&substream->dma_buffer);
192 substream->dma_buffer = new_dmab;
194 buffer->error = -EINVAL;
197 mutex_unlock(&substream->pcm->open_mutex);
200 static inline void preallocate_info_init(struct snd_pcm_substream *substream)
202 struct snd_info_entry *entry;
204 if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
205 entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
206 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
208 entry->private_data = substream;
209 if (snd_info_register(entry) < 0) {
210 snd_info_free_entry(entry);
214 substream->proc_prealloc_entry = entry;
215 if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
216 entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
217 entry->private_data = substream;
218 if (snd_info_register(entry) < 0) {
219 snd_info_free_entry(entry);
223 substream->proc_prealloc_max_entry = entry;
226 #else /* !CONFIG_SND_VERBOSE_PROCFS */
227 #define preallocate_info_init(s)
228 #endif /* CONFIG_SND_VERBOSE_PROCFS */
231 * pre-allocate the buffer and create a proc file for the substream
233 static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
234 size_t size, size_t max)
237 if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
238 preallocate_pcm_pages(substream, size);
240 if (substream->dma_buffer.bytes > 0)
241 substream->buffer_bytes_max = substream->dma_buffer.bytes;
242 substream->dma_max = max;
243 preallocate_info_init(substream);
249 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
250 * @substream: the pcm substream instance
251 * @type: DMA type (SNDRV_DMA_TYPE_*)
252 * @data: DMA type dependent data
253 * @size: the requested pre-allocation size in bytes
254 * @max: the max. allowed pre-allocation size
256 * Do pre-allocation for the given DMA buffer type.
258 * Return: Zero if successful, or a negative error code on failure.
260 int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
261 int type, struct device *data,
262 size_t size, size_t max)
264 substream->dma_buffer.dev.type = type;
265 substream->dma_buffer.dev.dev = data;
266 return snd_pcm_lib_preallocate_pages1(substream, size, max);
268 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
271 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
272 * @pcm: the pcm instance
273 * @type: DMA type (SNDRV_DMA_TYPE_*)
274 * @data: DMA type dependent data
275 * @size: the requested pre-allocation size in bytes
276 * @max: the max. allowed pre-allocation size
278 * Do pre-allocation to all substreams of the given pcm for the
279 * specified DMA type.
281 * Return: Zero if successful, or a negative error code on failure.
283 int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
284 int type, void *data,
285 size_t size, size_t max)
287 struct snd_pcm_substream *substream;
290 for (stream = 0; stream < 2; stream++)
291 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
292 if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
296 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
298 #ifdef CONFIG_SND_DMA_SGBUF
300 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
301 * @substream: the pcm substream instance
302 * @offset: the buffer offset
304 * Used as the page callback of PCM ops.
306 * Return: The page struct at the given buffer offset. %NULL on failure.
308 struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
310 struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
312 unsigned int idx = offset >> PAGE_SHIFT;
313 if (idx >= (unsigned int)sgbuf->pages)
315 return sgbuf->page_table[idx];
317 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
318 #endif /* CONFIG_SND_DMA_SGBUF */
321 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
322 * @substream: the substream to allocate the DMA buffer to
323 * @size: the requested buffer size in bytes
325 * Allocates the DMA buffer on the BUS type given earlier to
326 * snd_pcm_lib_preallocate_xxx_pages().
328 * Return: 1 if the buffer is changed, 0 if not changed, or a negative
331 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
333 struct snd_pcm_runtime *runtime;
334 struct snd_dma_buffer *dmab = NULL;
336 if (PCM_RUNTIME_CHECK(substream))
338 if (snd_BUG_ON(substream->dma_buffer.dev.type ==
339 SNDRV_DMA_TYPE_UNKNOWN))
341 runtime = substream->runtime;
343 if (runtime->dma_buffer_p) {
344 /* perphaps, we might free the large DMA memory region
345 to save some space here, but the actual solution
346 costs us less time */
347 if (runtime->dma_buffer_p->bytes >= size) {
348 runtime->dma_bytes = size;
349 return 0; /* ok, do not change */
351 snd_pcm_lib_free_pages(substream);
353 if (substream->dma_buffer.area != NULL &&
354 substream->dma_buffer.bytes >= size) {
355 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
357 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
360 dmab->dev = substream->dma_buffer.dev;
361 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
362 substream->dma_buffer.dev.dev,
368 snd_pcm_set_runtime_buffer(substream, dmab);
369 runtime->dma_bytes = size;
370 return 1; /* area was changed */
372 EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
375 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
376 * @substream: the substream to release the DMA buffer
378 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
380 * Return: Zero if successful, or a negative error code on failure.
382 int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
384 struct snd_pcm_runtime *runtime;
386 if (PCM_RUNTIME_CHECK(substream))
388 runtime = substream->runtime;
389 if (runtime->dma_area == NULL)
391 if (runtime->dma_buffer_p != &substream->dma_buffer) {
392 /* it's a newly allocated buffer. release it now. */
393 snd_dma_free_pages(runtime->dma_buffer_p);
394 kfree(runtime->dma_buffer_p);
396 snd_pcm_set_runtime_buffer(substream, NULL);
399 EXPORT_SYMBOL(snd_pcm_lib_free_pages);
401 int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
402 size_t size, gfp_t gfp_flags)
404 struct snd_pcm_runtime *runtime;
406 if (PCM_RUNTIME_CHECK(substream))
408 runtime = substream->runtime;
409 if (runtime->dma_area) {
410 if (runtime->dma_bytes >= size)
411 return 0; /* already large enough */
412 vfree(runtime->dma_area);
414 runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
415 if (!runtime->dma_area)
417 runtime->dma_bytes = size;
420 EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
423 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
424 * @substream: the substream with a buffer allocated by
425 * snd_pcm_lib_alloc_vmalloc_buffer()
427 * Return: Zero if successful, or a negative error code on failure.
429 int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
431 struct snd_pcm_runtime *runtime;
433 if (PCM_RUNTIME_CHECK(substream))
435 runtime = substream->runtime;
436 vfree(runtime->dma_area);
437 runtime->dma_area = NULL;
440 EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
443 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
444 * @substream: the substream with a buffer allocated by
445 * snd_pcm_lib_alloc_vmalloc_buffer()
446 * @offset: offset in the buffer
448 * This function is to be used as the page callback in the PCM ops.
450 * Return: The page struct, or %NULL on failure.
452 struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
453 unsigned long offset)
455 return vmalloc_to_page(substream->runtime->dma_area + offset);
457 EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);