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>

3 files changed, 12 insertions, 19 deletions

diff --git a/sound/soc/fsl/fsl_dma.c b/sound/soc/fsl/fsl_dma.c
index 9cc5c1f..f73c7ef 100644
--- a/sound/soc/fsl/fsl_dma.c
+++ b/sound/soc/fsl/fsl_dma.c
@@ -298,14 +298,11 @@ static int fsl_dma_new(struct snd_soc_pcm_runtime *rtd)
 {
 	struct snd_card *card = rtd->card->snd_card;
 	struct snd_pcm *pcm = rtd->pcm;
-	static u64 fsl_dma_dmamask = DMA_BIT_MASK(36);
 	int ret;
 
-	if (!card->dev->dma_mask)
-		card->dev->dma_mask = &fsl_dma_dmamask;
-
-	if (!card->dev->coherent_dma_mask)
-		card->dev->coherent_dma_mask = fsl_dma_dmamask;
+	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(36));
+	if (ret)
+		return ret;
 
 	/* Some codecs have separate DAIs for playback and capture, so we
 	 * should allocate a DMA buffer only for the streams that are valid.
diff --git a/sound/soc/fsl/imx-pcm-fiq.c b/sound/soc/fsl/imx-pcm-fiq.c
index 34043c5..fd5f2fb 100644
--- a/sound/soc/fsl/imx-pcm-fiq.c
+++ b/sound/soc/fsl/imx-pcm-fiq.c
@@ -272,18 +272,16 @@ static int imx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
 	return 0;
 }
 
-static u64 imx_pcm_dmamask = DMA_BIT_MASK(32);
-
 static int imx_pcm_new(struct snd_soc_pcm_runtime *rtd)
 {
 	struct snd_card *card = rtd->card->snd_card;
 	struct snd_pcm *pcm = rtd->pcm;
-	int ret = 0;
+	int ret;
+
+	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
+	if (ret)
+		return ret;
 
-	if (!card->dev->dma_mask)
-		card->dev->dma_mask = &imx_pcm_dmamask;
-	if (!card->dev->coherent_dma_mask)
-		card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
 	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
 		ret = imx_pcm_preallocate_dma_buffer(pcm,
 			SNDRV_PCM_STREAM_PLAYBACK);
diff --git a/sound/soc/fsl/mpc5200_dma.c b/sound/soc/fsl/mpc5200_dma.c
index 2a847ca..8fcf224 100644
--- a/sound/soc/fsl/mpc5200_dma.c
+++ b/sound/soc/fsl/mpc5200_dma.c
@@ -299,7 +299,6 @@ static struct snd_pcm_ops psc_dma_ops = {
 	.hw_params	= psc_dma_hw_params,
 };
 
-static u64 psc_dma_dmamask = DMA_BIT_MASK(32);
 static int psc_dma_new(struct snd_soc_pcm_runtime *rtd)
 {
 	struct snd_card *card = rtd->card->snd_card;
@@ -307,15 +306,14 @@ static int psc_dma_new(struct snd_soc_pcm_runtime *rtd)
 	struct snd_pcm *pcm = rtd->pcm;
 	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
 	size_t size = psc_dma_hardware.buffer_bytes_max;
-	int rc = 0;
+	int rc;
 
 	dev_dbg(rtd->platform->dev, "psc_dma_new(card=%p, dai=%p, pcm=%p)\n",
 		card, dai, pcm);
 
-	if (!card->dev->dma_mask)
-		card->dev->dma_mask = &psc_dma_dmamask;
-	if (!card->dev->coherent_dma_mask)
-		card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
+	rc = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
+	if (rc)
+		return rc;
 
 	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
 		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,