diff mbox

[v4,6/8] dmaengine: rcar-dmac: add iommu support for slave transfers

Message ID 1455655184-14478-7-git-send-email-niklas.soderlund+renesas@ragnatech.se (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show

Commit Message

Niklas Söderlund Feb. 16, 2016, 8:39 p.m. UTC
Enable slave transfers to devices behind IPMMU:s by mapping the slave
addresses using the dma-mapping API.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/dma/sh/rcar-dmac.c | 52 +++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 47 insertions(+), 5 deletions(-)

Comments

Vinod Koul March 7, 2016, 6:03 a.m. UTC | #1
On Tue, Feb 16, 2016 at 09:39:42PM +0100, Niklas Söderlund wrote:
> Enable slave transfers to devices behind IPMMU:s by mapping the slave

IPMMU:s ?

> addresses using the dma-mapping API.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  drivers/dma/sh/rcar-dmac.c | 52 +++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 47 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
> index 743873c..6a24847 100644
> --- a/drivers/dma/sh/rcar-dmac.c
> +++ b/drivers/dma/sh/rcar-dmac.c
> @@ -1106,21 +1106,63 @@ rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
>  	return desc;
>  }
>  
> +static int rcar_dmac_set_slave_addr(struct dma_chan *chan,
> +				     struct rcar_dmac_chan_slave *slave,
> +				     phys_addr_t addr, size_t size)
> +{
> +	enum dma_data_direction dir;
> +
> +	/*
> +	 * We can't know the direction at this time, see documentation for
> +	 * 'direction' in struct dma_slave_config.
> +	 */

Okay so we are mapping on the device config, which doesn't seem intutive.
Why is this not done during prepare calls?

> +	dir = DMA_BIDIRECTIONAL;
> +
> +	if (slave->xfer_size) {
> +		dma_unmap_resource(chan->device->dev, slave->slave_addr,
> +				   slave->xfer_size, dir, NULL);
> +		slave->slave_addr = 0;
> +		slave->xfer_size = 0;
> +	}
> +
> +	if (size) {
> +		slave->slave_addr = dma_map_resource(chan->device->dev, addr,
> +				size, dir, NULL);
> +
> +		if (dma_mapping_error(chan->device->dev, slave->slave_addr)) {
> +			struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
> +
> +			dev_err(chan->device->dev,
> +				"chan%u: failed to map %zx@%pap", rchan->index,
> +				size, &addr);
> +			return -EIO;
> +		}
> +
> +		slave->xfer_size = size;
> +	}
> +
> +	return 0;
> +}
> +
>  static int rcar_dmac_device_config(struct dma_chan *chan,
>  				   struct dma_slave_config *cfg)
>  {
>  	struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
> +	int ret;
>  
>  	/*
>  	 * We could lock this, but you shouldn't be configuring the
>  	 * channel, while using it...
>  	 */
> -	rchan->src.slave_addr = cfg->src_addr;
> -	rchan->dst.slave_addr = cfg->dst_addr;
> -	rchan->src.xfer_size = cfg->src_addr_width;
> -	rchan->dst.xfer_size = cfg->dst_addr_width;
>  
> -	return 0;
> +	ret = rcar_dmac_set_slave_addr(chan, &rchan->src, cfg->src_addr,
> +				       cfg->src_addr_width);
> +	if (ret)
> +		return ret;
> +
> +	ret = rcar_dmac_set_slave_addr(chan, &rchan->dst, cfg->dst_addr,
> +				       cfg->dst_addr_width);
> +	return ret;
>  }
>  
>  static int rcar_dmac_chan_terminate_all(struct dma_chan *chan)
> -- 
> 2.7.1
>
diff mbox

Patch

diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 743873c..6a24847 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -1106,21 +1106,63 @@  rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
 	return desc;
 }
 
+static int rcar_dmac_set_slave_addr(struct dma_chan *chan,
+				     struct rcar_dmac_chan_slave *slave,
+				     phys_addr_t addr, size_t size)
+{
+	enum dma_data_direction dir;
+
+	/*
+	 * We can't know the direction at this time, see documentation for
+	 * 'direction' in struct dma_slave_config.
+	 */
+	dir = DMA_BIDIRECTIONAL;
+
+	if (slave->xfer_size) {
+		dma_unmap_resource(chan->device->dev, slave->slave_addr,
+				   slave->xfer_size, dir, NULL);
+		slave->slave_addr = 0;
+		slave->xfer_size = 0;
+	}
+
+	if (size) {
+		slave->slave_addr = dma_map_resource(chan->device->dev, addr,
+				size, dir, NULL);
+
+		if (dma_mapping_error(chan->device->dev, slave->slave_addr)) {
+			struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
+
+			dev_err(chan->device->dev,
+				"chan%u: failed to map %zx@%pap", rchan->index,
+				size, &addr);
+			return -EIO;
+		}
+
+		slave->xfer_size = size;
+	}
+
+	return 0;
+}
+
 static int rcar_dmac_device_config(struct dma_chan *chan,
 				   struct dma_slave_config *cfg)
 {
 	struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
+	int ret;
 
 	/*
 	 * We could lock this, but you shouldn't be configuring the
 	 * channel, while using it...
 	 */
-	rchan->src.slave_addr = cfg->src_addr;
-	rchan->dst.slave_addr = cfg->dst_addr;
-	rchan->src.xfer_size = cfg->src_addr_width;
-	rchan->dst.xfer_size = cfg->dst_addr_width;
 
-	return 0;
+	ret = rcar_dmac_set_slave_addr(chan, &rchan->src, cfg->src_addr,
+				       cfg->src_addr_width);
+	if (ret)
+		return ret;
+
+	ret = rcar_dmac_set_slave_addr(chan, &rchan->dst, cfg->dst_addr,
+				       cfg->dst_addr_width);
+	return ret;
 }
 
 static int rcar_dmac_chan_terminate_all(struct dma_chan *chan)