linux/sound/core/sgbuf.c
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00

162 lines
3.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Scatter-Gather buffer
*
* Copyright (c) by Takashi Iwai <tiwai@suse.de>
*/
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/export.h>
#include <asm/pgtable.h>
#include <sound/memalloc.h>
/* table entries are align to 32 */
#define SGBUF_TBL_ALIGN 32
#define sgbuf_align_table(tbl) ALIGN((tbl), 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;
vunmap(dmab->area);
dmab->area = NULL;
tmpb.dev.type = SNDRV_DMA_TYPE_DEV;
if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_UC_SG)
tmpb.dev.type = SNDRV_DMA_TYPE_DEV_UC;
tmpb.dev.dev = sgbuf->dev;
for (i = 0; i < sgbuf->pages; i++) {
if (!(sgbuf->table[i].addr & ~PAGE_MASK))
continue; /* continuous pages */
tmpb.area = sgbuf->table[i].buf;
tmpb.addr = sgbuf->table[i].addr & PAGE_MASK;
tmpb.bytes = (sgbuf->table[i].addr & ~PAGE_MASK) << PAGE_SHIFT;
snd_dma_free_pages(&tmpb);
}
kfree(sgbuf->table);
kfree(sgbuf->page_table);
kfree(sgbuf);
dmab->private_data = NULL;
return 0;
}
#define MAX_ALLOC_PAGES 32
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, chunk, maxpages;
struct snd_dma_buffer tmpb;
struct snd_sg_page *table;
struct page **pgtable;
int type = SNDRV_DMA_TYPE_DEV;
pgprot_t prot = PAGE_KERNEL;
dmab->area = NULL;
dmab->addr = 0;
dmab->private_data = sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL);
if (! sgbuf)
return NULL;
if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_UC_SG) {
type = SNDRV_DMA_TYPE_DEV_UC;
#ifdef pgprot_noncached
prot = pgprot_noncached(PAGE_KERNEL);
#endif
}
sgbuf->dev = device;
pages = snd_sgbuf_aligned_pages(size);
sgbuf->tblsize = sgbuf_align_table(pages);
table = kcalloc(sgbuf->tblsize, sizeof(*table), GFP_KERNEL);
if (!table)
goto _failed;
sgbuf->table = table;
pgtable = kcalloc(sgbuf->tblsize, sizeof(*pgtable), GFP_KERNEL);
if (!pgtable)
goto _failed;
sgbuf->page_table = pgtable;
/* allocate pages */
maxpages = MAX_ALLOC_PAGES;
while (pages > 0) {
chunk = pages;
/* don't be too eager to take a huge chunk */
if (chunk > maxpages)
chunk = maxpages;
chunk <<= PAGE_SHIFT;
if (snd_dma_alloc_pages_fallback(type, device,
chunk, &tmpb) < 0) {
if (!sgbuf->pages)
goto _failed;
if (!res_size)
goto _failed;
size = sgbuf->pages * PAGE_SIZE;
break;
}
chunk = tmpb.bytes >> PAGE_SHIFT;
for (i = 0; i < chunk; i++) {
table->buf = tmpb.area;
table->addr = tmpb.addr;
if (!i)
table->addr |= chunk; /* mark head */
table++;
*pgtable++ = virt_to_page(tmpb.area);
tmpb.area += PAGE_SIZE;
tmpb.addr += PAGE_SIZE;
}
sgbuf->pages += chunk;
pages -= chunk;
if (chunk < maxpages)
maxpages = chunk;
}
sgbuf->size = size;
dmab->area = vmap(sgbuf->page_table, sgbuf->pages, VM_MAP, prot);
if (! dmab->area)
goto _failed;
if (res_size)
*res_size = sgbuf->size;
return dmab->area;
_failed:
snd_free_sgbuf_pages(dmab); /* free the table */
return NULL;
}
/*
* compute the max chunk size with continuous pages on sg-buffer
*/
unsigned int snd_sgbuf_get_chunk_size(struct snd_dma_buffer *dmab,
unsigned int ofs, unsigned int size)
{
struct snd_sg_buf *sg = dmab->private_data;
unsigned int start, end, pg;
start = ofs >> PAGE_SHIFT;
end = (ofs + size - 1) >> PAGE_SHIFT;
/* check page continuity */
pg = sg->table[start].addr >> PAGE_SHIFT;
for (;;) {
start++;
if (start > end)
break;
pg++;
if ((sg->table[start].addr >> PAGE_SHIFT) != pg)
return (start << PAGE_SHIFT) - ofs;
}
/* ok, all on continuous pages */
return size;
}
EXPORT_SYMBOL(snd_sgbuf_get_chunk_size);