diff options
Diffstat (limited to 'sound/core/sgbuf.c')
| -rw-r--r-- | sound/core/sgbuf.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/sound/core/sgbuf.c b/sound/core/sgbuf.c new file mode 100644 index 0000000..74745da --- /dev/null +++ b/sound/core/sgbuf.c @@ -0,0 +1,111 @@ +/* + * 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/config.h> +#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 = kmalloc(sizeof(*sgbuf), GFP_KERNEL); + if (! sgbuf) + return NULL; + memset(sgbuf, 0, sizeof(*sgbuf)); + sgbuf->dev = device; + pages = snd_sgbuf_aligned_pages(size); + sgbuf->tblsize = sgbuf_align_table(pages); + sgbuf->table = kmalloc(sizeof(*sgbuf->table) * sgbuf->tblsize, GFP_KERNEL); + if (! sgbuf->table) + goto _failed; + memset(sgbuf->table, 0, sizeof(*sgbuf->table) * sgbuf->tblsize); + sgbuf->page_table = kmalloc(sizeof(*sgbuf->page_table) * sgbuf->tblsize, GFP_KERNEL); + if (! sgbuf->page_table) + goto _failed; + memset(sgbuf->page_table, 0, sizeof(*sgbuf->page_table) * sgbuf->tblsize); + + /* 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; +} |
