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 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 * 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_size = 64;
197 entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
198 entry->c.text.write_size = 64;
199 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
200 entry->mode |= S_IWUSR;
201 entry->private_data = substream;
202 if (snd_info_register(entry) < 0) {
203 snd_info_free_entry(entry);
207 substream->proc_prealloc_entry = entry;
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 dependant 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 * When substream->dma_buf_id is set, the function tries to look for
243 * the reserved buffer, and the buffer is not freed but reserved at
244 * destruction time. The dma_buf_id must be unique for all systems
245 * (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id().
247 * Returns zero if successful, or a negative error code on failure.
249 int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
250 int type, struct device *data,
251 size_t size, size_t max)
253 substream->dma_buffer.dev.type = type;
254 substream->dma_buffer.dev.dev = data;
255 return snd_pcm_lib_preallocate_pages1(substream, size, max);
258 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
261 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continous memory type (all substreams)
262 * @pcm: the pcm instance
263 * @type: DMA type (SNDRV_DMA_TYPE_*)
264 * @data: DMA type dependant data
265 * @size: the requested pre-allocation size in bytes
266 * @max: the max. allowed pre-allocation size
268 * Do pre-allocation to all substreams of the given pcm for the
269 * specified DMA type.
271 * Returns zero if successful, or a negative error code on failure.
273 int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
274 int type, void *data,
275 size_t size, size_t max)
277 struct snd_pcm_substream *substream;
280 for (stream = 0; stream < 2; stream++)
281 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
282 if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
287 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
290 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
291 * @substream: the pcm substream instance
292 * @offset: the buffer offset
294 * Returns the page struct at the given buffer offset.
295 * Used as the page callback of PCM ops.
297 struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
299 struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
301 unsigned int idx = offset >> PAGE_SHIFT;
302 if (idx >= (unsigned int)sgbuf->pages)
304 return sgbuf->page_table[idx];
307 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
310 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
311 * @substream: the substream to allocate the DMA buffer to
312 * @size: the requested buffer size in bytes
314 * Allocates the DMA buffer on the BUS type given earlier to
315 * snd_pcm_lib_preallocate_xxx_pages().
317 * Returns 1 if the buffer is changed, 0 if not changed, or a negative
320 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
322 struct snd_pcm_runtime *runtime;
323 struct snd_dma_buffer *dmab = NULL;
325 snd_assert(substream->dma_buffer.dev.type != SNDRV_DMA_TYPE_UNKNOWN, return -EINVAL);
326 snd_assert(substream != NULL, return -EINVAL);
327 runtime = substream->runtime;
328 snd_assert(runtime != NULL, return -EINVAL);
330 if (runtime->dma_buffer_p) {
331 /* perphaps, we might free the large DMA memory region
332 to save some space here, but the actual solution
333 costs us less time */
334 if (runtime->dma_buffer_p->bytes >= size) {
335 runtime->dma_bytes = size;
336 return 0; /* ok, do not change */
338 snd_pcm_lib_free_pages(substream);
340 if (substream->dma_buffer.area != NULL &&
341 substream->dma_buffer.bytes >= size) {
342 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
344 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
347 dmab->dev = substream->dma_buffer.dev;
348 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
349 substream->dma_buffer.dev.dev,
355 snd_pcm_set_runtime_buffer(substream, dmab);
356 runtime->dma_bytes = size;
357 return 1; /* area was changed */
360 EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
363 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
364 * @substream: the substream to release the DMA buffer
366 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
368 * Returns zero if successful, or a negative error code on failure.
370 int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
372 struct snd_pcm_runtime *runtime;
374 snd_assert(substream != NULL, return -EINVAL);
375 runtime = substream->runtime;
376 snd_assert(runtime != NULL, return -EINVAL);
377 if (runtime->dma_area == NULL)
379 if (runtime->dma_buffer_p != &substream->dma_buffer) {
380 /* it's a newly allocated buffer. release it now. */
381 snd_dma_free_pages(runtime->dma_buffer_p);
382 kfree(runtime->dma_buffer_p);
384 snd_pcm_set_runtime_buffer(substream, NULL);
388 EXPORT_SYMBOL(snd_pcm_lib_free_pages);