diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 12adafa..a831e31 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -408,7 +408,8 @@ testpmd_mbuf_ctor(struct rte_mempool *mp,
 	mb->ol_flags     = 0;
 	mb->data_off     = RTE_PKTMBUF_HEADROOM;
 	mb->nb_segs      = 1;
-	mb->l2_l3_len       = 0;
+	mb->l2_len       = 0;
+	mb->l3_len       = 0;
 	mb->vlan_tci     = 0;
 	mb->hash.rss     = 0;
 }
diff --git a/examples/ipv4_multicast/main.c b/examples/ipv4_multicast/main.c
index de5e6be..a31d43d 100644
--- a/examples/ipv4_multicast/main.c
+++ b/examples/ipv4_multicast/main.c
@@ -302,7 +302,8 @@ mcast_out_pkt(struct rte_mbuf *pkt, int use_clone)
 	/* copy metadata from source packet*/
 	hdr->port = pkt->port;
 	hdr->vlan_tci = pkt->vlan_tci;
-	hdr->l2_l3_len = pkt->l2_l3_len;
+	hdr->l2_len = pkt->l2_len;
+	hdr->l3_len = pkt->l3_len;
 	hdr->hash = pkt->hash;
 
 	hdr->ol_flags = pkt->ol_flags;
diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index bcd8996..f76b768 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -126,6 +126,19 @@ extern "C" {
 
 #define PKT_TX_VXLAN_CKSUM   (1ULL << 50) /**< TX checksum of VXLAN computed by NIC */
 
+/**
+ * TCP segmentation offload. To enable this offload feature for a
+ * packet to be transmitted on hardware supporting TSO:
+ *  - set the PKT_TX_TCP_SEG flag in mbuf->ol_flags (this flag implies
+ *    PKT_TX_TCP_CKSUM)
+ *  - if it's IPv4, set the PKT_TX_IP_CKSUM flag and write the IP checksum
+ *    to 0 in the packet
+ *  - fill the mbuf offload information: l2_len, l3_len, l4_len, tso_segsz
+ *  - calculate the pseudo header checksum and set it in the TCP header,
+ *    as required when doing hardware TCP checksum offload
+ */
+#define PKT_TX_TCP_SEG       (1ULL << 49)
+
 /* Use final bit of flags to indicate a control mbuf */
 #define CTRL_MBUF_FLAG       (1ULL << 63) /**< Mbuf contains control data */
 
@@ -185,6 +198,7 @@ static inline const char *rte_get_tx_ol_flag_name(uint64_t mask)
 	case PKT_TX_UDP_CKSUM: return "PKT_TX_UDP_CKSUM";
 	case PKT_TX_IEEE1588_TMST: return "PKT_TX_IEEE1588_TMST";
 	case PKT_TX_VXLAN_CKSUM: return "PKT_TX_VXLAN_CKSUM";
+	case PKT_TX_TCP_SEG: return "PKT_TX_TCP_SEG";
 	default: return NULL;
 	}
 }
@@ -264,22 +278,18 @@ struct rte_mbuf {
 
 	/* fields to support TX offloads */
 	union {
-		uint16_t l2_l3_len; /**< combined l2/l3 lengths as single var */
+		uint64_t tx_offload;       /**< combined for easy fetch */
 		struct {
-			uint16_t l3_len:9;      /**< L3 (IP) Header Length. */
-			uint16_t l2_len:7;      /**< L2 (MAC) Header Length. */
-		};
-	};
+			uint64_t l2_len:7; /**< L2 (MAC) Header Length. */
+			uint64_t l3_len:9; /**< L3 (IP) Header Length. */
+			uint64_t l4_len:8; /**< L4 (TCP/UDP) Header Length. */
+			uint64_t tso_segsz:16; /**< TCP TSO segment size */
 
-	/* fields for TX offloading of tunnels */
-	union {
-		uint16_t inner_l2_l3_len;
-		/**< combined inner l2/l3 lengths as single var */
-		struct {
-			uint16_t inner_l3_len:9;
-			/**< inner L3 (IP) Header Length. */
-			uint16_t inner_l2_len:7;
-			/**< inner L2 (MAC) Header Length. */
+			/* fields for TX offloading of tunnels */
+			uint16_t inner_l3_len:9; /**< inner L3 (IP) Hdr Length. */
+			uint16_t inner_l2_len:7; /**< inner L2 (MAC) Hdr Length. */
+
+			/* uint64_t unused:8; */
 		};
 	};
 } __rte_cache_aligned;
@@ -631,8 +641,7 @@ static inline void rte_pktmbuf_reset(struct rte_mbuf *m)
 {
 	m->next = NULL;
 	m->pkt_len = 0;
-	m->l2_l3_len = 0;
-	m->inner_l2_l3_len = 0;
+	m->tx_offload = 0;
 	m->vlan_tci = 0;
 	m->nb_segs = 1;
 	m->port = 0xff;
@@ -701,8 +710,7 @@ static inline void rte_pktmbuf_attach(struct rte_mbuf *mi, struct rte_mbuf *md)
 	mi->data_len = md->data_len;
 	mi->port = md->port;
 	mi->vlan_tci = md->vlan_tci;
-	mi->l2_l3_len = md->l2_l3_len;
-	mi->inner_l2_l3_len = md->inner_l2_l3_len;
+	mi->tx_offload = md->tx_offload;
 	mi->hash = md->hash;
 
 	mi->next = NULL;
diff --git a/lib/librte_pmd_e1000/igb_rxtx.c b/lib/librte_pmd_e1000/igb_rxtx.c
index dbf5074..0a9447e 100644
--- a/lib/librte_pmd_e1000/igb_rxtx.c
+++ b/lib/librte_pmd_e1000/igb_rxtx.c
@@ -361,6 +361,13 @@ eth_igb_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 	struct rte_mbuf     *tx_pkt;
 	struct rte_mbuf     *m_seg;
 	union igb_vlan_macip vlan_macip_lens;
+	union {
+		uint16_t u16;
+		struct {
+			uint16_t l3_len:9;
+			uint16_t l2_len:7;
+		};
+	} l2_l3_len;
 	uint64_t buf_dma_addr;
 	uint32_t olinfo_status;
 	uint32_t cmd_type_len;
@@ -398,8 +405,10 @@ eth_igb_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 		tx_last = (uint16_t) (tx_id + tx_pkt->nb_segs - 1);
 
 		ol_flags = tx_pkt->ol_flags;
+		l2_l3_len.l2_len = tx_pkt->l2_len;
+		l2_l3_len.l3_len = tx_pkt->l3_len;
 		vlan_macip_lens.f.vlan_tci = tx_pkt->vlan_tci;
-		vlan_macip_lens.f.l2_l3_len = tx_pkt->l2_l3_len;
+		vlan_macip_lens.f.l2_l3_len = l2_l3_len.u16;
 		tx_ol_req = ol_flags & (PKT_TX_VLAN_PKT | PKT_TX_IP_CKSUM |
 			PKT_TX_L4_MASK);
 
diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
index 70ca254..54a0fc1 100644
--- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
+++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
@@ -540,6 +540,13 @@ ixgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 	struct rte_mbuf     *tx_pkt;
 	struct rte_mbuf     *m_seg;
 	union ixgbe_vlan_macip vlan_macip_lens;
+	union {
+		uint16_t u16;
+		struct {
+			uint16_t l3_len:9;
+			uint16_t l2_len:7;
+		};
+	} l2_l3_len;
 	uint64_t buf_dma_addr;
 	uint32_t olinfo_status;
 	uint32_t cmd_type_len;
@@ -583,8 +590,10 @@ ixgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 		tx_ol_req = ol_flags & (PKT_TX_VLAN_PKT | PKT_TX_IP_CKSUM |
 			PKT_TX_L4_MASK);
 		if (tx_ol_req) {
+			l2_l3_len.l2_len = tx_pkt->l2_len;
+			l2_l3_len.l3_len = tx_pkt->l3_len;
 			vlan_macip_lens.f.vlan_tci = tx_pkt->vlan_tci;
-			vlan_macip_lens.f.l2_l3_len = tx_pkt->l2_l3_len;
+			vlan_macip_lens.f.l2_l3_len = l2_l3_len.u16;
 
 			/* If new context need be built or reuse the exist ctx. */
 			ctx = what_advctx_update(txq, tx_ol_req,
