ASoC: dmaengine: Use iov_iter for process callback, too

Along with the conversion to PCM copy ops, use the iov_iter for the
pointer to be passed to the dmaengine process callback, too.  It
avoids the direct reference of iter_iov_addr(), and it can potentially
help for the drivers to access memory properly (although both atmel
and stm drivers don't use the given buffer address at all for now).
Reviewed-by: Mark Brown <broonie@kernel.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Claudiu Beznea <claudiu.beznea@microchip.com>
Cc: Olivier Moysan <olivier.moysan@foss.st.com>
Cc: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Link: https://lore.kernel.org/r/20230815190136.8987-23-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/dmaengine_pcm.h

@@ -142,7 +142,7 @@ struct snd_dmaengine_pcm_config {
 			struct snd_pcm_substream *substream);
 	int (*process)(struct snd_pcm_substream *substream,
 		       int channel, unsigned long hwoff,
-		       void *buf, unsigned long bytes);
+		       struct iov_iter *buf, unsigned long bytes);
 	dma_filter_fn compat_filter_fn;
 	struct device *dma_dev;
 	const char *chan_names[SNDRV_PCM_STREAM_LAST + 1];

sound/soc/atmel/mchp-pdmc.c

@@ -954,7 +954,7 @@ static int mchp_pdmc_dt_init(struct mchp_pdmc *dd)
 /* used to clean the channel index found on RHR's MSB */
 static int mchp_pdmc_process(struct snd_pcm_substream *substream,
 			     int channel, unsigned long hwoff,
-			     void *buf, unsigned long bytes)
+			     struct iov_iter *buf, unsigned long bytes)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	u8 *dma_ptr = runtime->dma_area + hwoff +

sound/soc/soc-generic-dmaengine-pcm.c

@@ -296,18 +296,17 @@ static int dmaengine_copy(struct snd_soc_component *component,
 	struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 	int (*process)(struct snd_pcm_substream *substream,
 		       int channel, unsigned long hwoff,
-		       void *buf, unsigned long bytes) = pcm->config->process;
+		       struct iov_iter *buf, unsigned long bytes) = pcm->config->process;
 	bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 	void *dma_ptr = runtime->dma_area + hwoff +
 			channel * (runtime->dma_bytes / runtime->channels);
-	void *ptr = (void __force *)iter_iov_addr(buf);
 
 	if (is_playback)
 		if (copy_from_iter(dma_ptr, bytes, buf) != bytes)
 			return -EFAULT;
 
 	if (process) {
-		int ret = process(substream, channel, hwoff, ptr, bytes);
+		int ret = process(substream, channel, hwoff, buf, bytes);
 		if (ret < 0)
 			return ret;
 	}

sound/soc/stm/stm32_sai_sub.c

@@ -1233,7 +1233,7 @@ static const struct snd_soc_dai_ops stm32_sai_pcm_dai_ops = {
 
 static int stm32_sai_pcm_process_spdif(struct snd_pcm_substream *substream,
 				       int channel, unsigned long hwoff,
-				       void *buf, unsigned long bytes)
+				       struct iov_iter *buf, unsigned long bytes)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);