crypto: mxs-dcp - Check for DMA mapping errors

After calling dma_map_single(), we must also call dma_mapping_error().
This fixes the following warning when compiling with CONFIG_DMA_API_DEBUG:

[  311.241478] WARNING: CPU: 0 PID: 428 at kernel/dma/debug.c:1027 check_unmap+0x79c/0x96c
[  311.249547] DMA-API: mxs-dcp 2280000.crypto: device driver failed to check map error[device address=0x00000000860cb080] [size=32 bytes] [mapped as single]
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/mxs-dcp.c

@@ -170,15 +170,19 @@ static struct dcp *global_sdcp;
 
 static int mxs_dcp_start_dma(struct dcp_async_ctx *actx)
 {
+	int dma_err;
 	struct dcp *sdcp = global_sdcp;
 	const int chan = actx->chan;
 	uint32_t stat;
 	unsigned long ret;
 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
-
 	dma_addr_t desc_phys = dma_map_single(sdcp->dev, desc, sizeof(*desc),
 					      DMA_TO_DEVICE);
 
+	dma_err = dma_mapping_error(sdcp->dev, desc_phys);
+	if (dma_err)
+		return dma_err;
+
 	reinit_completion(&sdcp->completion[chan]);
 
 	/* Clear status register. */
@@ -216,18 +220,29 @@ static int mxs_dcp_start_dma(struct dcp_async_ctx *actx)
 static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
 			   struct skcipher_request *req, int init)
 {
+	dma_addr_t key_phys, src_phys, dst_phys;
 	struct dcp *sdcp = global_sdcp;
 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
 	struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
 	int ret;
 
-	dma_addr_t key_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_key,
-					     2 * AES_KEYSIZE_128,
-					     DMA_TO_DEVICE);
-	dma_addr_t src_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_in_buf,
-					     DCP_BUF_SZ, DMA_TO_DEVICE);
-	dma_addr_t dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
-					     DCP_BUF_SZ, DMA_FROM_DEVICE);
+	key_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_key,
+				  2 * AES_KEYSIZE_128, DMA_TO_DEVICE);
+	ret = dma_mapping_error(sdcp->dev, key_phys);
+	if (ret)
+		return ret;
+
+	src_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_in_buf,
+				  DCP_BUF_SZ, DMA_TO_DEVICE);
+	ret = dma_mapping_error(sdcp->dev, src_phys);
+	if (ret)
+		goto err_src;
+
+	dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
+				  DCP_BUF_SZ, DMA_FROM_DEVICE);
+	ret = dma_mapping_error(sdcp->dev, dst_phys);
+	if (ret)
+		goto err_dst;
 
 	if (actx->fill % AES_BLOCK_SIZE) {
 		dev_err(sdcp->dev, "Invalid block size!\n");
@@ -265,10 +280,12 @@ static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
 	ret = mxs_dcp_start_dma(actx);
 
 aes_done_run:
+	dma_unmap_single(sdcp->dev, dst_phys, DCP_BUF_SZ, DMA_FROM_DEVICE);
+err_dst:
+	dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
+err_src:
 	dma_unmap_single(sdcp->dev, key_phys, 2 * AES_KEYSIZE_128,
 			 DMA_TO_DEVICE);
-	dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
-	dma_unmap_single(sdcp->dev, dst_phys, DCP_BUF_SZ, DMA_FROM_DEVICE);
 
 	return ret;
 }
@@ -557,6 +574,10 @@ static int mxs_dcp_run_sha(struct ahash_request *req)
 	dma_addr_t buf_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_in_buf,
 					     DCP_BUF_SZ, DMA_TO_DEVICE);
 
+	ret = dma_mapping_error(sdcp->dev, buf_phys);
+	if (ret)
+		return ret;
+
 	/* Fill in the DMA descriptor. */
 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
 		    MXS_DCP_CONTROL0_INTERRUPT |
@@ -589,6 +610,10 @@ static int mxs_dcp_run_sha(struct ahash_request *req)
 	if (rctx->fini) {
 		digest_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_out_buf,
 					     DCP_SHA_PAY_SZ, DMA_FROM_DEVICE);
+		ret = dma_mapping_error(sdcp->dev, digest_phys);
+		if (ret)
+			goto done_run;
+
 		desc->control0 |= MXS_DCP_CONTROL0_HASH_TERM;
 		desc->payload = digest_phys;
 	}