[PATCH] dma: mv_xor: Fix missing check after DMA map and missing unmap

[Thomas Fourier <fourier.thomas@gmail.com>]

The DMA map functions can fail and should be tested for errors.

In case of error, unmap the already mapped regions.

Fixes: 22843545b200 ("dma: mv_xor: Add support for DMA_INTERRUPT")
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
---
 drivers/dma/mv_xor.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
index fa6e4646fdc2..1fdcb0f5c9e7 100644
--- a/drivers/dma/mv_xor.c
+++ b/drivers/dma/mv_xor.c
@@ -1061,8 +1061,16 @@ mv_xor_channel_add(struct mv_xor_device *xordev,
 	 */
 	mv_chan->dummy_src_addr = dma_map_single(dma_dev->dev,
 		mv_chan->dummy_src, MV_XOR_MIN_BYTE_COUNT, DMA_FROM_DEVICE);
+	if (dma_mapping_error(dma_dev->dev, mv_chan->dummy_src_addr))
+		return ERR_PTR(-ENOMEM);
+
 	mv_chan->dummy_dst_addr = dma_map_single(dma_dev->dev,
 		mv_chan->dummy_dst, MV_XOR_MIN_BYTE_COUNT, DMA_TO_DEVICE);
+	if (dma_mapping_error(dma_dev->dev, mv_chan->dummy_dst_addr)) {
+		ret = -ENOMEM;
+		goto err_unmap_src;
+	}
+
 
 	/* allocate coherent memory for hardware descriptors
 	 * note: writecombine gives slightly better performance, but
@@ -1071,8 +1079,10 @@ mv_xor_channel_add(struct mv_xor_device *xordev,
 	mv_chan->dma_desc_pool_virt =
 	  dma_alloc_wc(&pdev->dev, MV_XOR_POOL_SIZE, &mv_chan->dma_desc_pool,
 		       GFP_KERNEL);
-	if (!mv_chan->dma_desc_pool_virt)
-		return ERR_PTR(-ENOMEM);
+	if (!mv_chan->dma_desc_pool_virt) {
+		ret = -ENOMEM;
+		goto err_unmap_dst;
+	}
 
 	/* discover transaction capabilities from the platform data */
 	dma_dev->cap_mask = cap_mask;
@@ -1155,6 +1165,13 @@ mv_xor_channel_add(struct mv_xor_device *xordev,
 err_free_dma:
 	dma_free_coherent(&pdev->dev, MV_XOR_POOL_SIZE,
 			  mv_chan->dma_desc_pool_virt, mv_chan->dma_desc_pool);
+err_unmap_dst:
+	dma_unmap_single(dma_dev->dev, mv_chan->dummy_dst_addr,
+			 MV_XOR_MIN_BYTE_COUNT, DMA_TO_DEVICE);
+err_unmap_src:
+	dma_unmap_single(dma_dev->dev, mv_chan->dummy_src_addr,
+			 MV_XOR_MIN_BYTE_COUNT, DMA_FROM_DEVICE);
+
 	return ERR_PTR(ret);
 }
 
-- 
2.43.0