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|
/*
* Digital Audio (PCM) abstract layer
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <asm/io.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/moduleparam.h>
#include <linux/vmalloc.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/info.h>
#include <sound/initval.h>
static int preallocate_dma = 1;
module_param(preallocate_dma, int, 0444);
MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
static int maximum_substreams = 4;
module_param(maximum_substreams, int, 0444);
MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
static const size_t snd_minimum_buffer = 16384;
/*
* try to allocate as the large pages as possible.
* stores the resultant memory size in *res_size.
*
* the minimum size is snd_minimum_buffer. it should be power of 2.
*/
static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
{
struct snd_dma_buffer *dmab = &substream->dma_buffer;
int err;
/* already reserved? */
if (snd_dma_get_reserved_buf(dmab, substream->dma_buf_id) > 0) {
if (dmab->bytes >= size)
return 0; /* yes */
/* no, free the reserved block */
snd_dma_free_pages(dmab);
dmab->bytes = 0;
}
do {
if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
size, dmab)) < 0) {
if (err != -ENOMEM)
return err; /* fatal error */
} else
return 0;
size >>= 1;
} while (size >= snd_minimum_buffer);
dmab->bytes = 0; /* tell error */
return 0;
}
/*
* release the preallocated buffer if not yet done.
*/
static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
{
if (substream->dma_buffer.area == NULL)
return;
if (substream->dma_buf_id)
snd_dma_reserve_buf(&substream->dma_buffer, substream->dma_buf_id);
else
snd_dma_free_pages(&substream->dma_buffer);
substream->dma_buffer.area = NULL;
}
/**
* snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
* @substream: the pcm substream instance
*
* Releases the pre-allocated buffer of the given substream.
*
* Returns zero if successful, or a negative error code on failure.
*/
int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
{
snd_pcm_lib_preallocate_dma_free(substream);
#ifdef CONFIG_SND_VERBOSE_PROCFS
snd_info_free_entry(substream->proc_prealloc_max_entry);
substream->proc_prealloc_max_entry = NULL;
snd_info_free_entry(substream->proc_prealloc_entry);
substream->proc_prealloc_entry = NULL;
#endif
return 0;
}
/**
* snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
* @pcm: the pcm instance
*
* Releases all the pre-allocated buffers on the given pcm.
*
* Returns zero if successful, or a negative error code on failure.
*/
int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
{
struct snd_pcm_substream *substream;
int stream;
for (stream = 0; stream < 2; stream++)
for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
snd_pcm_lib_preallocate_free(substream);
return 0;
}
EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
#ifdef CONFIG_SND_VERBOSE_PROCFS
/*
* read callback for prealloc proc file
*
* prints the current allocated size in kB.
*/
static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_pcm_substream *substream = entry->private_data;
snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
}
/*
* read callback for prealloc_max proc file
*
* prints the maximum allowed size in kB.
*/
static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_pcm_substream *substream = entry->private_data;
snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
}
/*
* write callback for prealloc proc file
*
* accepts the preallocation size in kB.
*/
static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_pcm_substream *substream = entry->private_data;
char line[64], str[64];
size_t size;
struct snd_dma_buffer new_dmab;
if (substream->runtime) {
buffer->error = -EBUSY;
return;
}
if (!snd_info_get_line(buffer, line, sizeof(line))) {
snd_info_get_str(str, line, sizeof(str));
size = simple_strtoul(str, NULL, 10) * 1024;
if ((size != 0 && size < 8192) || size > substream->dma_max) {
buffer->error = -EINVAL;
return;
}
if (substream->dma_buffer.bytes == size)
return;
memset(&new_dmab, 0, sizeof(new_dmab));
new_dmab.dev = substream->dma_buffer.dev;
if (size > 0) {
if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
substream->dma_buffer.dev.dev,
size, &new_dmab) < 0) {
buffer->error = -ENOMEM;
return;
}
substream->buffer_bytes_max = size;
} else {
substream->buffer_bytes_max = UINT_MAX;
}
if (substream->dma_buffer.area)
snd_dma_free_pages(&substream->dma_buffer);
substream->dma_buffer = new_dmab;
} else {
buffer->error = -EINVAL;
}
}
static inline void preallocate_info_init(struct snd_pcm_substream *substream)
{
struct snd_info_entry *entry;
if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
entry->mode |= S_IWUSR;
entry->private_data = substream;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
entry = NULL;
}
}
substream->proc_prealloc_entry = entry;
if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
entry->private_data = substream;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
entry = NULL;
}
}
substream->proc_prealloc_max_entry = entry;
}
#else /* !CONFIG_SND_VERBOSE_PROCFS */
#define preallocate_info_init(s)
#endif /* CONFIG_SND_VERBOSE_PROCFS */
/*
* pre-allocate the buffer and create a proc file for the substream
*/
static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
size_t size, size_t max)
{
if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
preallocate_pcm_pages(substream, size);
if (substream->dma_buffer.bytes > 0)
substream->buffer_bytes_max = substream->dma_buffer.bytes;
substream->dma_max = max;
preallocate_info_init(substream);
return 0;
}
/**
* snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
* @substream: the pcm substream instance
* @type: DMA type (SNDRV_DMA_TYPE_*)
* @data: DMA type dependent data
* @size: the requested pre-allocation size in bytes
* @max: the max. allowed pre-allocation size
*
* Do pre-allocation for the given DMA buffer type.
*
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