android_kernel_samsung_sm8650/sound/soc/atmel/atmel-pcm.c
Russell King c9bd5e690a DMA-API: sound: fix dma mask handling in a lot of drivers
This code sequence is unsafe in modules:

static u64 mask = DMA_BIT_MASK(something);
...
	if (!dev->dma_mask)
		dev->dma_mask = &mask;

as if a module is reloaded, the mask will be pointing at the original
module's mask address, and this can lead to oopses.  Moreover, they
all follow this with:

	if (!dev->coherent_dma_mask)
		dev->coherent_dma_mask = mask;

where 'mask' is the same value as the statically defined mask, and this
bypasses the architecture's check on whether the DMA mask is possible.

Fix these issues by using the new dma_coerce_coherent_and_mask()
function.

Acked-by: Mark Brown <broonie@linaro.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-10-31 14:48:47 +00:00

122 lines
3.3 KiB
C

/*
* atmel-pcm.c -- ALSA PCM interface for the Atmel atmel SoC.
*
* Copyright (C) 2005 SAN People
* Copyright (C) 2008 Atmel
*
* Authors: Sedji Gaouaou <sedji.gaouaou@atmel.com>
*
* Based on at91-pcm. by:
* Frank Mandarino <fmandarino@endrelia.com>
* Copyright 2006 Endrelia Technologies Inc.
*
* Based on pxa2xx-pcm.c by:
*
* Author: Nicolas Pitre
* Created: Nov 30, 2004
* Copyright: (C) 2004 MontaVista Software, Inc.
*
* 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/module.h>
#include <linux/dma-mapping.h>
#include <sound/pcm.h>
#include <sound/soc.h>
#include "atmel-pcm.h"
static int atmel_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
int stream)
{
struct snd_pcm_substream *substream = pcm->streams[stream].substream;
struct snd_dma_buffer *buf = &substream->dma_buffer;
size_t size = ATMEL_SSC_DMABUF_SIZE;
buf->dev.type = SNDRV_DMA_TYPE_DEV;
buf->dev.dev = pcm->card->dev;
buf->private_data = NULL;
buf->area = dma_alloc_coherent(pcm->card->dev, size,
&buf->addr, GFP_KERNEL);
pr_debug("atmel-pcm: alloc dma buffer: area=%p, addr=%p, size=%zu\n",
(void *)buf->area, (void *)buf->addr, size);
if (!buf->area)
return -ENOMEM;
buf->bytes = size;
return 0;
}
int atmel_pcm_mmap(struct snd_pcm_substream *substream,
struct vm_area_struct *vma)
{
return remap_pfn_range(vma, vma->vm_start,
substream->dma_buffer.addr >> PAGE_SHIFT,
vma->vm_end - vma->vm_start, vma->vm_page_prot);
}
EXPORT_SYMBOL_GPL(atmel_pcm_mmap);
int atmel_pcm_new(struct snd_soc_pcm_runtime *rtd)
{
struct snd_card *card = rtd->card->snd_card;
struct snd_pcm *pcm = rtd->pcm;
int ret;
ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
if (ret)
return ret;
if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
pr_debug("atmel-pcm: allocating PCM playback DMA buffer\n");
ret = atmel_pcm_preallocate_dma_buffer(pcm,
SNDRV_PCM_STREAM_PLAYBACK);
if (ret)
goto out;
}
if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
pr_debug("atmel-pcm: allocating PCM capture DMA buffer\n");
ret = atmel_pcm_preallocate_dma_buffer(pcm,
SNDRV_PCM_STREAM_CAPTURE);
if (ret)
goto out;
}
out:
return ret;
}
EXPORT_SYMBOL_GPL(atmel_pcm_new);
void atmel_pcm_free(struct snd_pcm *pcm)
{
struct snd_pcm_substream *substream;
struct snd_dma_buffer *buf;
int stream;
for (stream = 0; stream < 2; stream++) {
substream = pcm->streams[stream].substream;
if (!substream)
continue;
buf = &substream->dma_buffer;
if (!buf->area)
continue;
dma_free_coherent(pcm->card->dev, buf->bytes,
buf->area, buf->addr);
buf->area = NULL;
}
}
EXPORT_SYMBOL_GPL(atmel_pcm_free);