net: hns3: clean up for vlan handling in hns3_fill_desc_vtags

This patch refactors the hns3_fill_desc_vtags function
by avoiding passing too many parameters, reducing indent
level and some other clean up.

This patch also adds the hns3_fill_skb_desc function to
fill the first desc of a skb.
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Reviewed-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hns3_enet.c

@@ -45,6 +45,9 @@ MODULE_PARM_DESC(debug, " Network interface message level setting");
 #define DEFAULT_MSG_LEVEL (NETIF_MSG_PROBE | NETIF_MSG_LINK | \
 			   NETIF_MSG_IFDOWN | NETIF_MSG_IFUP)
 
+#define HNS3_INNER_VLAN_TAG	1
+#define HNS3_OUTER_VLAN_TAG	2
+
 /* hns3_pci_tbl - PCI Device ID Table
  *
  * Last entry must be all 0s
@@ -961,16 +964,16 @@ static void hns3_set_txbd_baseinfo(u16 *bdtp_fe_sc_vld_ra_ri, int frag_end)
 	hns3_set_field(*bdtp_fe_sc_vld_ra_ri, HNS3_TXD_VLD_B, 1U);
 }
 
-static int hns3_fill_desc_vtags(struct sk_buff *skb,
-				struct hns3_enet_ring *tx_ring,
-				u32 *inner_vlan_flag,
-				u32 *out_vlan_flag,
-				u16 *inner_vtag,
-				u16 *out_vtag)
+static int hns3_handle_vtags(struct hns3_enet_ring *tx_ring,
+			     struct sk_buff *skb)
 {
-#define HNS3_TX_VLAN_PRIO_SHIFT 13
-
 	struct hnae3_handle *handle = tx_ring->tqp->handle;
+	struct vlan_ethhdr *vhdr;
+	int rc;
+
+	if (!(skb->protocol == htons(ETH_P_8021Q) ||
+	      skb_vlan_tag_present(skb)))
+		return 0;
 
 	/* Since HW limitation, if port based insert VLAN enabled, only one VLAN
 	 * header is allowed in skb, otherwise it will cause RAS error.
@@ -981,8 +984,7 @@ static int hns3_fill_desc_vtags(struct sk_buff *skb,
 		return -EINVAL;
 
 	if (skb->protocol == htons(ETH_P_8021Q) &&
-	    !(tx_ring->tqp->handle->kinfo.netdev->features &
-	    NETIF_F_HW_VLAN_CTAG_TX)) {
+	    !(handle->kinfo.netdev->features & NETIF_F_HW_VLAN_CTAG_TX)) {
 		/* When HW VLAN acceleration is turned off, and the stack
 		 * sets the protocol to 802.1q, the driver just need to
 		 * set the protocol to the encapsulated ethertype.
@@ -992,59 +994,35 @@ static int hns3_fill_desc_vtags(struct sk_buff *skb,
 	}
 
 	if (skb_vlan_tag_present(skb)) {
-		u16 vlan_tag;
-
-		vlan_tag = skb_vlan_tag_get(skb);
-		vlan_tag |= (skb->priority & 0x7) << HNS3_TX_VLAN_PRIO_SHIFT;
-
 		/* Based on hw strategy, use out_vtag in two layer tag case,
 		 * and use inner_vtag in one tag case.
 		 */
-		if (skb->protocol == htons(ETH_P_8021Q)) {
-			if (handle->port_base_vlan_state ==
-			    HNAE3_PORT_BASE_VLAN_DISABLE){
-				hns3_set_field(*out_vlan_flag,
-					       HNS3_TXD_OVLAN_B, 1);
-				*out_vtag = vlan_tag;
-			} else {
-				hns3_set_field(*inner_vlan_flag,
-					       HNS3_TXD_VLAN_B, 1);
-				*inner_vtag = vlan_tag;
-			}
-		} else {
-			hns3_set_field(*inner_vlan_flag, HNS3_TXD_VLAN_B, 1);
-			*inner_vtag = vlan_tag;
+		if (skb->protocol == htons(ETH_P_8021Q) &&
+		    handle->port_base_vlan_state ==
+		    HNAE3_PORT_BASE_VLAN_DISABLE)
+			rc = HNS3_OUTER_VLAN_TAG;
+		else
+			rc = HNS3_INNER_VLAN_TAG;
+
+		skb->protocol = vlan_get_protocol(skb);
+		return rc;
 	}
-	} else if (skb->protocol == htons(ETH_P_8021Q)) {
-		struct vlan_ethhdr *vhdr;
-		int rc;
 
 	rc = skb_cow_head(skb, 0);
 	if (unlikely(rc < 0))
 		return rc;
+
 	vhdr = (struct vlan_ethhdr *)skb->data;
-		vhdr->h_vlan_TCI |= cpu_to_be16((skb->priority & 0x7)
-					<< HNS3_TX_VLAN_PRIO_SHIFT);
-	}
+	vhdr->h_vlan_TCI |= cpu_to_be16((skb->priority << VLAN_PRIO_SHIFT)
+					 & VLAN_PRIO_MASK);
 
 	skb->protocol = vlan_get_protocol(skb);
 	return 0;
 }
 
-static int hns3_fill_desc(struct hns3_enet_ring *ring, void *priv,
-			  unsigned int size, int frag_end,
-			  enum hns_desc_type type)
+static int hns3_fill_skb_desc(struct hns3_enet_ring *ring,
+			      struct sk_buff *skb, struct hns3_desc *desc)
 {
-	struct hns3_desc_cb *desc_cb = &ring->desc_cb[ring->next_to_use];
-	struct hns3_desc *desc = &ring->desc[ring->next_to_use];
-	struct device *dev = ring_to_dev(ring);
-	skb_frag_t *frag;
-	unsigned int frag_buf_num;
-	int k, sizeoflast;
-	dma_addr_t dma;
-
-	if (type == DESC_TYPE_SKB) {
-		struct sk_buff *skb = (struct sk_buff *)priv;
 	u32 ol_type_vlan_len_msec = 0;
 	u32 type_cs_vlan_tso = 0;
 	u32 paylen = skb->len;
@@ -1053,11 +1031,21 @@ static int hns3_fill_desc(struct hns3_enet_ring *ring, void *priv,
 	u16 mss = 0;
 	int ret;
 
-		ret = hns3_fill_desc_vtags(skb, ring, &type_cs_vlan_tso,
-					   &ol_type_vlan_len_msec,
-					   &inner_vtag, &out_vtag);
-		if (unlikely(ret))
+	ret = hns3_handle_vtags(ring, skb);
+	if (unlikely(ret < 0)) {
 		return ret;
+	} else if (ret == HNS3_INNER_VLAN_TAG) {
+		inner_vtag = skb_vlan_tag_get(skb);
+		inner_vtag |= (skb->priority << VLAN_PRIO_SHIFT) &
+				VLAN_PRIO_MASK;
+		hns3_set_field(type_cs_vlan_tso, HNS3_TXD_VLAN_B, 1);
+	} else if (ret == HNS3_OUTER_VLAN_TAG) {
+		out_vtag = skb_vlan_tag_get(skb);
+		out_vtag |= (skb->priority << VLAN_PRIO_SHIFT) &
+				VLAN_PRIO_MASK;
+		hns3_set_field(ol_type_vlan_len_msec, HNS3_TXD_OVLAN_B,
+			       1);
+	}
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		u8 ol4_proto, il4_proto;
@@ -1089,6 +1077,29 @@ static int hns3_fill_desc(struct hns3_enet_ring *ring, void *priv,
 	desc->tx.vlan_tag = cpu_to_le16(inner_vtag);
 	desc->tx.outer_vlan_tag = cpu_to_le16(out_vtag);
 
+	return 0;
+}
+
+static int hns3_fill_desc(struct hns3_enet_ring *ring, void *priv,
+			  unsigned int size, int frag_end,
+			  enum hns_desc_type type)
+{
+	struct hns3_desc_cb *desc_cb = &ring->desc_cb[ring->next_to_use];
+	struct hns3_desc *desc = &ring->desc[ring->next_to_use];
+	struct device *dev = ring_to_dev(ring);
+	skb_frag_t *frag;
+	unsigned int frag_buf_num;
+	int k, sizeoflast;
+	dma_addr_t dma;
+
+	if (type == DESC_TYPE_SKB) {
+		struct sk_buff *skb = (struct sk_buff *)priv;
+		int ret;
+
+		ret = hns3_fill_skb_desc(ring, skb, desc);
+		if (unlikely(ret))
+			return ret;
+
 		dma = dma_map_single(dev, skb->data, size, DMA_TO_DEVICE);
 	} else {
 		frag = (skb_frag_t *)priv;