dmaengine: fsl-edma: dma map slave device address

This mapping needs to be created in order for slave dma transfers
to work on systems with SMMU. The implementation mostly mimics the
one in pl330 dma driver, authored by Robin Murphy.

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Angelo Dureghello <angelo@sysam.it>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 62 insertions, 4 deletions

diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c
index fe529100674f..680b2a00a953 100644
--- a/drivers/dma/fsl-edma-common.c
+++ b/drivers/dma/fsl-edma-common.c
@@ -6,6 +6,7 @@
 #include <linux/dmapool.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/dma-mapping.h>
 
 #include "fsl-edma-common.h"
 
@@ -173,12 +174,62 @@ int fsl_edma_resume(struct dma_chan *chan)
 }
 EXPORT_SYMBOL_GPL(fsl_edma_resume);
 
+static void fsl_edma_unprep_slave_dma(struct fsl_edma_chan *fsl_chan)
+{
+	if (fsl_chan->dma_dir != DMA_NONE)
+		dma_unmap_resource(fsl_chan->vchan.chan.device->dev,
+				   fsl_chan->dma_dev_addr,
+				   fsl_chan->dma_dev_size,
+				   fsl_chan->dma_dir, 0);
+	fsl_chan->dma_dir = DMA_NONE;
+}
+
+static bool fsl_edma_prep_slave_dma(struct fsl_edma_chan *fsl_chan,
+				    enum dma_transfer_direction dir)
+{
+	struct device *dev = fsl_chan->vchan.chan.device->dev;
+	enum dma_data_direction dma_dir;
+	phys_addr_t addr = 0;
+	u32 size = 0;
+
+	switch (dir) {
+	case DMA_MEM_TO_DEV:
+		dma_dir = DMA_FROM_DEVICE;
+		addr = fsl_chan->cfg.dst_addr;
+		size = fsl_chan->cfg.dst_maxburst;
+		break;
+	case DMA_DEV_TO_MEM:
+		dma_dir = DMA_TO_DEVICE;
+		addr = fsl_chan->cfg.src_addr;
+		size = fsl_chan->cfg.src_maxburst;
+		break;
+	default:
+		dma_dir = DMA_NONE;
+		break;
+	}
+
+	/* Already mapped for this config? */
+	if (fsl_chan->dma_dir == dma_dir)
+		return true;
+
+	fsl_edma_unprep_slave_dma(fsl_chan);
+
+	fsl_chan->dma_dev_addr = dma_map_resource(dev, addr, size, dma_dir, 0);
+	if (dma_mapping_error(dev, fsl_chan->dma_dev_addr))
+		return false;
+	fsl_chan->dma_dev_size = size;
+	fsl_chan->dma_dir = dma_dir;
+
+	return true;
+}
+
 int fsl_edma_slave_config(struct dma_chan *chan,
 				 struct dma_slave_config *cfg)
 {
 	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
 
 	memcpy(&fsl_chan->cfg, cfg, sizeof(*cfg));
+	fsl_edma_unprep_slave_dma(fsl_chan);
 
 	return 0;
 }
@@ -376,6 +427,9 @@ struct dma_async_tx_descriptor *fsl_edma_prep_dma_cyclic(
 	if (!is_slave_direction(direction))
 		return NULL;
 
+	if (!fsl_edma_prep_slave_dma(fsl_chan, direction))
+		return NULL;
+
 	sg_len = buf_len / period_len;
 	fsl_desc = fsl_edma_alloc_desc(fsl_chan, sg_len);
 	if (!fsl_desc)
@@ -407,11 +461,11 @@ struct dma_async_tx_descriptor *fsl_edma_prep_dma_cyclic(
 
 		if (direction == DMA_MEM_TO_DEV) {
 			src_addr = dma_buf_next;
-			dst_addr = fsl_chan->cfg.dst_addr;
+			dst_addr = fsl_chan->dma_dev_addr;
 			soff = fsl_chan->cfg.dst_addr_width;
 			doff = 0;
 		} else {
-			src_addr = fsl_chan->cfg.src_addr;
+			src_addr = fsl_chan->dma_dev_addr;
 			dst_addr = dma_buf_next;
 			soff = 0;
 			doff = fsl_chan->cfg.src_addr_width;
@@ -442,6 +496,9 @@ struct dma_async_tx_descriptor *fsl_edma_prep_slave_sg(
 	if (!is_slave_direction(direction))
 		return NULL;
 
+	if (!fsl_edma_prep_slave_dma(fsl_chan, direction))
+		return NULL;
+
 	fsl_desc = fsl_edma_alloc_desc(fsl_chan, sg_len);
 	if (!fsl_desc)
 		return NULL;
@@ -466,11 +523,11 @@ struct dma_async_tx_descriptor *fsl_edma_prep_slave_sg(
 
 		if (direction == DMA_MEM_TO_DEV) {
 			src_addr = sg_dma_address(sg);
-			dst_addr = fsl_chan->cfg.dst_addr;
+			dst_addr = fsl_chan->dma_dev_addr;
 			soff = fsl_chan->cfg.dst_addr_width;
 			doff = 0;
 		} else {
-			src_addr = fsl_chan->cfg.src_addr;
+			src_addr = fsl_chan->dma_dev_addr;
 			dst_addr = sg_dma_address(sg);
 			soff = 0;
 			doff = fsl_chan->cfg.src_addr_width;
@@ -553,6 +610,7 @@ void fsl_edma_free_chan_resources(struct dma_chan *chan)
 	fsl_edma_chan_mux(fsl_chan, 0, false);
 	fsl_chan->edesc = NULL;
 	vchan_get_all_descriptors(&fsl_chan->vchan, &head);
+	fsl_edma_unprep_slave_dma(fsl_chan);
 	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
 
 	vchan_dma_desc_free_list(&fsl_chan->vchan, &head);