/*
* Scatter-Gather buffer
*
* Copyright (c) by Takashi Iwai <tiwai@suse.de>
*
* 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 <linux/slab.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <sound/memalloc.h>
/* table entries are align to 32 */
#define SGBUF_TBL_ALIGN 32
#define sgbuf_align_table(tbl) ((((tbl) + SGBUF_TBL_ALIGN - 1) / SGBUF_TBL_ALIGN) * SGBUF_TBL_ALIGN)
int snd_free_sgbuf_pages(struct snd_dma_buffer *dmab)
{
struct snd_sg_buf *sgbuf = dmab->private_data;
struct snd_dma_buffer tmpb;
int i;
if (! sgbuf)
return -EINVAL;
tmpb.dev.type = SNDRV_DMA_TYPE_DEV;
tmpb.dev.dev = sgbuf->dev;
for (i = 0; i < sgbuf->pages; i++) {
tmpb.area = sgbuf->table[i].buf;
tmpb.addr = sgbuf->table[i].addr;
tmpb.bytes = PAGE_SIZE;
snd_dma_free_pages(&tmpb);
}
if (dmab->area)
vunmap(dmab->area);
dmab->area = NULL;
kfree(sgbuf->table);
kfree(sgbuf->page_table);
kfree(sgbuf);
dmab->private_data = NULL;
return 0;
}
void *snd_malloc_sgbuf_pages(struct device *device,
size_t size, struct snd_dma_buffer *dmab,
size_t *res_size)
{
struct snd_sg_buf *sgbuf;
unsigned int i, pages;
struct snd_dma_buffer tmpb;
dmab->area = NULL;
dmab->addr = 0;
dmab->private_data = sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL);
if (! sgbuf)
return NULL;
sgbuf->dev = device;
pages = snd_sgbuf_aligned_pages(size);
sgbuf->tblsize = sgbuf_align_table(pages);
sgbuf->table = kcalloc(sgbuf->tblsize, sizeof(*sgbuf->table), GFP_KERNEL);
if (! sgbuf->table)
goto _failed;
sgbuf->page_table = kcalloc(sgbuf->tblsize, sizeof(*sgbuf->page_table), GFP_KERNEL);
if (! sgbuf->page_table)
goto _failed;
/* allocate each page */
for (i = 0; i < pages; i++) {
if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, device, PAGE_SIZE, &tmpb) < 0) {
if (res_size == NULL)
goto _failed;
*res_size = size = sgbuf->pages * PAGE_SIZE;
break;
}
sgbuf->table[i].buf = tmpb.area;
sgbuf->table[i].addr = tmpb.addr;
sgbuf->page_table[i] = virt_to_page(tmpb.area);
sgbuf->pages++;
}
sgbuf->size = size;
dmab->area = vmap(sgbuf->page_table, sgbuf->pages, VM_MAP, PAGE_KERNEL);
if (! dmab->area)
goto _failed;
return dmab->area;
_failed:
snd_free_sgbuf_pages(dmab); /* free the table */
return NULL;
}
