net: hns3: use dma_zalloc_coherent instead of kzalloc/dma_map_single

Reference to Documentation/DMA-API-HOWTO.txt,
Streaming DMA mappings which are usually mapped for one DMA transfer,
Network card DMA ring descriptors should use Consistent DMA mappings.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 16 deletions

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index beca36491025..8fce36329bb0 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -1780,33 +1780,27 @@ static void hns3_free_buffers(struct hns3_enet_ring *ring)
 /* free desc along with its attached buffer */
 static void hns3_free_desc(struct hns3_enet_ring *ring)
 {
+	int size = ring->desc_num * sizeof(ring->desc[0]);
+
 	hns3_free_buffers(ring);
 
-	dma_unmap_single(ring_to_dev(ring), ring->desc_dma_addr,
-			 ring->desc_num * sizeof(ring->desc[0]),
-			 DMA_BIDIRECTIONAL);
-	ring->desc_dma_addr = 0;
-	kfree(ring->desc);
-	ring->desc = NULL;
+	if (ring->desc) {
+		dma_free_coherent(ring_to_dev(ring), size,
+				  ring->desc, ring->desc_dma_addr);
+		ring->desc = NULL;
+	}
 }
 
 static int hns3_alloc_desc(struct hns3_enet_ring *ring)
 {
 	int size = ring->desc_num * sizeof(ring->desc[0]);
 
-	ring->desc = kzalloc(size, GFP_KERNEL);
+	ring->desc = dma_zalloc_coherent(ring_to_dev(ring), size,
+					 &ring->desc_dma_addr,
+					 GFP_KERNEL);
 	if (!ring->desc)
 		return -ENOMEM;
 
-	ring->desc_dma_addr = dma_map_single(ring_to_dev(ring), ring->desc,
-					     size, DMA_BIDIRECTIONAL);
-	if (dma_mapping_error(ring_to_dev(ring), ring->desc_dma_addr)) {
-		ring->desc_dma_addr = 0;
-		kfree(ring->desc);
-		ring->desc = NULL;
-		return -ENOMEM;
-	}
-
 	return 0;
 }