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>

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;
 }
 

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_cmd.c

@@ -45,31 +45,24 @@ static int hclge_alloc_cmd_desc(struct hclge_cmq_ring *ring)
 {
 	int size  = ring->desc_num * sizeof(struct hclge_desc);
 
-	ring->desc = kzalloc(size, GFP_KERNEL);
+	ring->desc = dma_zalloc_coherent(cmq_ring_to_dev(ring),
+					 size, &ring->desc_dma_addr,
+					 GFP_KERNEL);
 	if (!ring->desc)
 		return -ENOMEM;
 
-	ring->desc_dma_addr = dma_map_single(cmq_ring_to_dev(ring), ring->desc,
-					     size, DMA_BIDIRECTIONAL);
-	if (dma_mapping_error(cmq_ring_to_dev(ring), ring->desc_dma_addr)) {
-		ring->desc_dma_addr = 0;
-		kfree(ring->desc);
-		ring->desc = NULL;
-		return -ENOMEM;
-	}
-
 	return 0;
 }
 
 static void hclge_free_cmd_desc(struct hclge_cmq_ring *ring)
 {
-	dma_unmap_single(cmq_ring_to_dev(ring), ring->desc_dma_addr,
-			 ring->desc_num * sizeof(ring->desc[0]),
-			 DMA_BIDIRECTIONAL);
+	int size  = ring->desc_num * sizeof(struct hclge_desc);
 
-	ring->desc_dma_addr = 0;
-	kfree(ring->desc);
-	ring->desc = NULL;
+	if (ring->desc) {
+		dma_free_coherent(cmq_ring_to_dev(ring), size,
+				  ring->desc, ring->desc_dma_addr);
+		ring->desc = NULL;
+	}
 }
 
 static int hclge_alloc_cmd_queue(struct hclge_dev *hdev, int ring_type)

drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_cmd.c

@@ -76,32 +76,24 @@ static int hclgevf_alloc_cmd_desc(struct hclgevf_cmq_ring *ring)
 {
 	int size = ring->desc_num * sizeof(struct hclgevf_desc);
 
-	ring->desc = kzalloc(size, GFP_KERNEL);
+	ring->desc = dma_zalloc_coherent(cmq_ring_to_dev(ring),
+					 size, &ring->desc_dma_addr,
+					 GFP_KERNEL);
 	if (!ring->desc)
 		return -ENOMEM;
 
-	ring->desc_dma_addr = dma_map_single(cmq_ring_to_dev(ring), ring->desc,
-					     size, DMA_BIDIRECTIONAL);
-
-	if (dma_mapping_error(cmq_ring_to_dev(ring), ring->desc_dma_addr)) {
-		ring->desc_dma_addr = 0;
-		kfree(ring->desc);
-		ring->desc = NULL;
-		return -ENOMEM;
-	}
-
 	return 0;
 }
 
 static void hclgevf_free_cmd_desc(struct hclgevf_cmq_ring *ring)
 {
-	dma_unmap_single(cmq_ring_to_dev(ring), ring->desc_dma_addr,
-			 ring->desc_num * sizeof(ring->desc[0]),
-			 hclgevf_ring_to_dma_dir(ring));
+	int size  = ring->desc_num * sizeof(struct hclgevf_desc);
 
-	ring->desc_dma_addr = 0;
-	kfree(ring->desc);
-	ring->desc = NULL;
+	if (ring->desc) {
+		dma_free_coherent(cmq_ring_to_dev(ring), size,
+				  ring->desc, ring->desc_dma_addr);
+		ring->desc = NULL;
+	}
 }
 
 static int hclgevf_init_cmd_queue(struct hclgevf_dev *hdev,