6af845e4eb
In snd_free_sgbuf_pags(), vunmap() is called after releasing the SG pages, and it causes errors on Xen as Xen manages the pages differently. Although no significant errors have been reported on the actual hardware, this order should be fixed other way round, first vunmap() then free pages. Cc: Jan Beulich <jbeulich@novell.com> Cc: <stable@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
138 lines
3.5 KiB
C
138 lines
3.5 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) ALIGN((tbl), 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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if (dmab->area)
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vunmap(dmab->area);
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dmab->area = NULL;
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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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if (!(sgbuf->table[i].addr & ~PAGE_MASK))
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continue; /* continuous pages */
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tmpb.area = sgbuf->table[i].buf;
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tmpb.addr = sgbuf->table[i].addr & PAGE_MASK;
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tmpb.bytes = (sgbuf->table[i].addr & ~PAGE_MASK) << PAGE_SHIFT;
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snd_dma_free_pages(&tmpb);
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}
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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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#define MAX_ALLOC_PAGES 32
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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, chunk, maxpages;
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struct snd_dma_buffer tmpb;
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struct snd_sg_page *table;
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struct page **pgtable;
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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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table = kcalloc(sgbuf->tblsize, sizeof(*table), GFP_KERNEL);
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if (!table)
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goto _failed;
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sgbuf->table = table;
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pgtable = kcalloc(sgbuf->tblsize, sizeof(*pgtable), GFP_KERNEL);
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if (!pgtable)
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goto _failed;
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sgbuf->page_table = pgtable;
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/* allocate pages */
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maxpages = MAX_ALLOC_PAGES;
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while (pages > 0) {
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chunk = pages;
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/* don't be too eager to take a huge chunk */
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if (chunk > maxpages)
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chunk = maxpages;
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chunk <<= PAGE_SHIFT;
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if (snd_dma_alloc_pages_fallback(SNDRV_DMA_TYPE_DEV, device,
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chunk, &tmpb) < 0) {
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if (!sgbuf->pages)
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return NULL;
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if (!res_size)
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goto _failed;
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size = sgbuf->pages * PAGE_SIZE;
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break;
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}
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chunk = tmpb.bytes >> PAGE_SHIFT;
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for (i = 0; i < chunk; i++) {
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table->buf = tmpb.area;
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table->addr = tmpb.addr;
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if (!i)
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table->addr |= chunk; /* mark head */
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table++;
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*pgtable++ = virt_to_page(tmpb.area);
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tmpb.area += PAGE_SIZE;
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tmpb.addr += PAGE_SIZE;
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}
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sgbuf->pages += chunk;
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pages -= chunk;
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if (chunk < maxpages)
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maxpages = chunk;
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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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if (res_size)
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*res_size = sgbuf->size;
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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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