/*
* Digital Audio (PCM) abstract layer
* Copyright (c) by Jaroslav Kysela <perex@suse.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 <sound/driver.h>
#include <asm/io.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/moduleparam.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(snd_pcm_substream_t *substream, size_t size)
{
struct snd_dma_buffer *dmab = &substream->dma_buffer;
int err;
snd_assert(size > 0, return -EINVAL);
/* 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(snd_pcm_substream_t *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(snd_pcm_substream_t *substream)
{
snd_pcm_lib_preallocate_dma_free(substream);
if (substream->proc_prealloc_entry) {
snd_info_unregister(substream->proc_prealloc_entry);
substream->proc_prealloc_entry = NULL;
}
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(snd_pcm_t *pcm)
{
snd_pcm_substream_t *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;
}
/*
* read callback for prealloc proc file
*
* prints the current allocated size in kB.
*/
static void snd_pcm_lib_preallocate_proc_read(snd_info_entry_t *entry,
snd_info_buffer_t *buffer)
{
snd_pcm_substream_t *substream = (snd_pcm_substream_t *)entry->private_data;
snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
}
/*
* write callback for prealloc proc file
*
* accepts the preallocation size in kB.
*/
static void snd_pcm_lib_preallocate_proc_write(snd_info_entry_t *entry,
snd_info_buffer_t *buffer)
{
snd_pcm_substream_t *substream = (snd_pcm_substream_t *)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;
}
}
/*
* pre-allocate the buffer and create a proc file for the substream
*/
static int snd_pcm_lib_preallocate_pages1(snd_pcm_substream_t *substream,
size_t size, size_t max)
{
snd_info_entry_t *entry;
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;
if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
entry->c.text.read_size = 64;
entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
entry->c.text.write_size = 64;
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;
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 dependant 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.
*
* When substream->dma_buf_id is set, the function tries to look for
* the reserved buffer, and the buffer is not freed but reserved at
* destruction time. The dma_buf_id must be unique for all systems
* (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id().
*
* Returns zero if successful, or a negative error code on failure.
*/
int snd_pcm_lib_preallocate_pages(snd_pcm_substream_t *substream,
int type, struct device *data,
size_t size, size_t max)
{
substream->dma_buffer.dev.type = type;
substream->dma_buffer.dev.dev = data;
return snd_pcm_lib_preallocate_pages1(substream, size, max);
}
/**
* snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continous memory type (all substreams)
* @substream: the pcm substream instance
* @type: DMA type (SNDRV_DMA_TYPE_*)
* @data: DMA type dependant data
* @size: the requested pre-allocation size in bytes
* @max: the max. allowed pre-allocation size
*
* Do pre-allocation to all substreams of the given pcm for the
* specified DMA type.
*
* Returns zero if successful, or a negative error code on failure.
*/
int snd_pcm_lib_preallocate_pages_for_all(snd_pcm_t *pcm,
int type, void *data,
size_t size, size_t max)
{
snd_pcm_substream_t *substream;
int stream, err;
for (stream = 0; stream < 2; stream++)
for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
return err;
return 0;
}
/**
* snd_pcm_sgbuf_ops_page - get the page struct at the given offset
* @substream: the pcm substream instance
* @offset: the buffer offset
*
* Returns the page struct at the given buffer offset.
* Used as the page callback of PCM ops.
*/
struct page *snd_pcm_sgbuf_ops_page(snd_pcm_substream_t *substream, unsigned long offset)
{
struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
unsigned int idx = offset >> PAGE_SHIFT;
if (idx >= (unsigned int)sgbuf->pages)
return NULL;
return sgbuf->page_table[idx];
}
/**
* snd_pcm_lib_malloc_pages - allocate the DMA buffer
* @substream: the substream to allocate the DMA buffer to
* @size: the requested buffer size in bytes
*
* Allocates the DMA buffer on the BUS type given earlier to
* snd_pcm_lib_preallocate_xxx_pages().
*
* Returns 1 if the buffer is changed, 0 if not changed, or a negative
* code on failure.
*/
int snd_pcm_lib_malloc_pages(snd_pcm_substream_t *substream, size_t size)
{
snd_pcm_runtime_t *runtime;
struct snd_dma_buffer *dmab = NULL;
snd_assert(substream->dma_buffer.dev.type != SNDRV_DMA_TYPE_UNKNOWN, return -EINVAL);
snd_assert(substream != NULL, return -EINVAL);
runtime = substream->runtime;
snd_assert(runtime != NULL, return -EINVAL);
if (runtime->dma_buffer_p) {
/* perphaps, we might free the large DMA memory region
to save some space here, but the actual solution
costs us less time */
if (runtime->dma_buffer_p->bytes >= size) {
runtime->dma_bytes = size;
return 0; /* ok, do not change */
}
snd_pcm_lib_free_pages(substream);
}
if (substream->dma_buffer.area != NULL && substream->dma_buffer.bytes >= size) {
dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
} else {
dmab = kcalloc(1, sizeof(*dmab), GFP_KERNEL);
if (! dmab)
return -ENOMEM;
dmab->dev = substream->dma_buffer.dev;
if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
substream->dma_buffer.dev.dev,
size, dmab) < 0) {
kfree(dmab);
return -ENOMEM;
}
}
snd_pcm_set_runtime_buffer(substream, dmab);
runtime->dma_bytes = size;
return 1; /* area was changed */
}
/**
* snd_pcm_lib_free_pages - release the allocated DMA buffer.
* @substream: the substream to release the DMA buffer
*
* Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
*
* Returns zero if successful, or a negative error code on failure.
*/
int snd_pcm_lib_free_pages(snd_pcm_substream_t *substream)
{
snd_pcm_runtime_t *runtime;
snd_assert(substream != NULL, return -EINVAL);
runtime = substream->runtime;
snd_assert(runtime != NULL, return -EINVAL);
if (runtime->dma_area == NULL)
return 0;
if (runtime->dma_buffer_p != &substream->dma_buffer) {
/* it's a newly allocated buffer. release it now. */
snd_dma_free_pages(runtime->dma_buffer_p);
kfree(runtime->dma_buffer_p);
}
snd_pcm_set_runtime_buffer(substream, NULL);
return 0;
}
