nfp: support UDP segmentation offload

The device supports UDP hardware segmentation offload, which helps
improving the performance. Thus, this patch adds support for UDP
segmentation offload from the driver side.
Signed-off-by: Fei Qin <fei.qin@corigine.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/nfd3/dp.c

@@ -74,7 +74,7 @@ static void
 nfp_nfd3_tx_tso(struct nfp_net_r_vector *r_vec, struct nfp_nfd3_tx_buf *txbuf,
 		struct nfp_nfd3_tx_desc *txd, struct sk_buff *skb, u32 md_bytes)
 {
-	u32 l3_offset, l4_offset, hdrlen;
+	u32 l3_offset, l4_offset, hdrlen, l4_hdrlen;
 	u16 mss;
 
 	if (!skb_is_gso(skb))
@@ -83,13 +83,16 @@ nfp_nfd3_tx_tso(struct nfp_net_r_vector *r_vec, struct nfp_nfd3_tx_buf *txbuf,
 	if (!skb->encapsulation) {
 		l3_offset = skb_network_offset(skb);
 		l4_offset = skb_transport_offset(skb);
-		hdrlen = skb_tcp_all_headers(skb);
+		l4_hdrlen = (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) ?
+			    sizeof(struct udphdr) : tcp_hdrlen(skb);
 	} else {
 		l3_offset = skb_inner_network_offset(skb);
 		l4_offset = skb_inner_transport_offset(skb);
-		hdrlen = skb_inner_tcp_all_headers(skb);
+		l4_hdrlen = (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) ?
+			    sizeof(struct udphdr) : inner_tcp_hdrlen(skb);
 	}
 
+	hdrlen = l4_offset + l4_hdrlen;
 	txbuf->pkt_cnt = skb_shinfo(skb)->gso_segs;
 	txbuf->real_len += hdrlen * (txbuf->pkt_cnt - 1);
 

drivers/net/ethernet/netronome/nfp/nfdk/dp.c

@@ -40,20 +40,23 @@ static __le64
 nfp_nfdk_tx_tso(struct nfp_net_r_vector *r_vec, struct nfp_nfdk_tx_buf *txbuf,
 		struct sk_buff *skb)
 {
-	u32 segs, hdrlen, l3_offset, l4_offset;
+	u32 segs, hdrlen, l3_offset, l4_offset, l4_hdrlen;
 	struct nfp_nfdk_tx_desc txd;
 	u16 mss;
 
 	if (!skb->encapsulation) {
 		l3_offset = skb_network_offset(skb);
 		l4_offset = skb_transport_offset(skb);
-		hdrlen = skb_tcp_all_headers(skb);
+		l4_hdrlen = (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) ?
+			    sizeof(struct udphdr) : tcp_hdrlen(skb);
 	} else {
 		l3_offset = skb_inner_network_offset(skb);
 		l4_offset = skb_inner_transport_offset(skb);
-		hdrlen = skb_inner_tcp_all_headers(skb);
+		l4_hdrlen = (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) ?
+			    sizeof(struct udphdr) : inner_tcp_hdrlen(skb);
 	}
 
+	hdrlen = l4_offset + l4_hdrlen;
 	segs = skb_shinfo(skb)->gso_segs;
 	mss = skb_shinfo(skb)->gso_size & NFDK_DESC_TX_MSS_MASK;
 

drivers/net/ethernet/netronome/nfp/nfp_net_common.c

@@ -2116,7 +2116,10 @@ nfp_net_features_check(struct sk_buff *skb, struct net_device *dev,
 	if (skb_is_gso(skb)) {
 		u32 hdrlen;
 
-		hdrlen = skb_inner_tcp_all_headers(skb);
+		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
+			hdrlen = skb_inner_transport_offset(skb) + sizeof(struct udphdr);
+		else
+			hdrlen = skb_inner_tcp_all_headers(skb);
 
 		/* Assume worst case scenario of having longest possible
 		 * metadata prepend - 8B
@@ -2419,7 +2422,7 @@ void nfp_net_info(struct nfp_net *nn)
 		nn->fw_ver.extend, nn->fw_ver.class,
 		nn->fw_ver.major, nn->fw_ver.minor,
 		nn->max_mtu);
-	nn_info(nn, "CAP: %#x %s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
+	nn_info(nn, "CAP: %#x %s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
 		nn->cap,
 		nn->cap & NFP_NET_CFG_CTRL_PROMISC  ? "PROMISC "  : "",
 		nn->cap & NFP_NET_CFG_CTRL_L2BC     ? "L2BCFILT " : "",
@@ -2448,6 +2451,7 @@ void nfp_net_info(struct nfp_net *nn)
 						      "RXCSUM_COMPLETE " : "",
 		nn->cap & NFP_NET_CFG_CTRL_LIVE_ADDR ? "LIVE_ADDR " : "",
 		nn->cap_w1 & NFP_NET_CFG_CTRL_MCAST_FILTER ? "MULTICAST_FILTER " : "",
+		nn->cap_w1 & NFP_NET_CFG_CTRL_USO ? "USO " : "",
 		nfp_app_extra_cap(nn->app, nn));
 }
 
@@ -2696,6 +2700,8 @@ static void nfp_net_netdev_init(struct nfp_net *nn)
 	if ((nn->cap & NFP_NET_CFG_CTRL_LSO && nn->fw_ver.major > 2) ||
 	    nn->cap & NFP_NET_CFG_CTRL_LSO2) {
 		netdev->hw_features |= NETIF_F_TSO | NETIF_F_TSO6;
+		if (nn->cap_w1 & NFP_NET_CFG_CTRL_USO)
+			netdev->hw_features |= NETIF_F_GSO_UDP_L4;
 		nn->dp.ctrl |= nn->cap & NFP_NET_CFG_CTRL_LSO2 ?:
 					 NFP_NET_CFG_CTRL_LSO;
 	}

drivers/net/ethernet/netronome/nfp/nfp_net_ctrl.h

@@ -270,6 +270,7 @@
 #define   NFP_NET_CFG_CTRL_MCAST_FILTER	  (0x1 << 2) /* Multicast Filter */
 #define   NFP_NET_CFG_CTRL_FREELIST_EN	  (0x1 << 6) /* Freelist enable flag bit */
 #define   NFP_NET_CFG_CTRL_FLOW_STEER	  (0x1 << 8) /* Flow steering */
+#define   NFP_NET_CFG_CTRL_USO		  (0x1 << 16) /* UDP segmentation offload */
 
 #define NFP_NET_CFG_CAP_WORD1		0x00a4