108 lines
2.9 KiB
C
108 lines
2.9 KiB
C
/*
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* Scatter-Gather buffer
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*
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* Copyright (c) by Takashi Iwai <tiwai@suse.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <linux/slab.h>
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#include <linux/mm.h>
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#include <linux/vmalloc.h>
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#include <sound/memalloc.h>
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/* table entries are align to 32 */
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#define SGBUF_TBL_ALIGN 32
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#define sgbuf_align_table(tbl) ((((tbl) + SGBUF_TBL_ALIGN - 1) / SGBUF_TBL_ALIGN) * SGBUF_TBL_ALIGN)
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int snd_free_sgbuf_pages(struct snd_dma_buffer *dmab)
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{
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struct snd_sg_buf *sgbuf = dmab->private_data;
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struct snd_dma_buffer tmpb;
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int i;
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if (! sgbuf)
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return -EINVAL;
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tmpb.dev.type = SNDRV_DMA_TYPE_DEV;
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tmpb.dev.dev = sgbuf->dev;
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for (i = 0; i < sgbuf->pages; i++) {
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tmpb.area = sgbuf->table[i].buf;
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tmpb.addr = sgbuf->table[i].addr;
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tmpb.bytes = PAGE_SIZE;
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snd_dma_free_pages(&tmpb);
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}
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if (dmab->area)
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vunmap(dmab->area);
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dmab->area = NULL;
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kfree(sgbuf->table);
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kfree(sgbuf->page_table);
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kfree(sgbuf);
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dmab->private_data = NULL;
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return 0;
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}
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void *snd_malloc_sgbuf_pages(struct device *device,
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size_t size, struct snd_dma_buffer *dmab,
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size_t *res_size)
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{
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struct snd_sg_buf *sgbuf;
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unsigned int i, pages;
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struct snd_dma_buffer tmpb;
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dmab->area = NULL;
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dmab->addr = 0;
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dmab->private_data = sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL);
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if (! sgbuf)
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return NULL;
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sgbuf->dev = device;
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pages = snd_sgbuf_aligned_pages(size);
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sgbuf->tblsize = sgbuf_align_table(pages);
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sgbuf->table = kcalloc(sgbuf->tblsize, sizeof(*sgbuf->table), GFP_KERNEL);
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if (! sgbuf->table)
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goto _failed;
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sgbuf->page_table = kcalloc(sgbuf->tblsize, sizeof(*sgbuf->page_table), GFP_KERNEL);
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if (! sgbuf->page_table)
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goto _failed;
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/* allocate each page */
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for (i = 0; i < pages; i++) {
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if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, device, PAGE_SIZE, &tmpb) < 0) {
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if (res_size == NULL)
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goto _failed;
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*res_size = size = sgbuf->pages * PAGE_SIZE;
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break;
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}
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sgbuf->table[i].buf = tmpb.area;
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sgbuf->table[i].addr = tmpb.addr;
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sgbuf->page_table[i] = virt_to_page(tmpb.area);
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sgbuf->pages++;
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}
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sgbuf->size = size;
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dmab->area = vmap(sgbuf->page_table, sgbuf->pages, VM_MAP, PAGE_KERNEL);
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if (! dmab->area)
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goto _failed;
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return dmab->area;
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_failed:
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snd_free_sgbuf_pages(dmab); /* free the table */
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return NULL;
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}
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