cxgb4: add UDP segmentation offload support

Implement and export UDP segmentation offload (USO) support for both
NIC and MQPRIO QoS offload Tx path. Update appropriate logic in Tx to
parse GSO info in skb and configure FW_ETH_TX_EO_WR request needed to
perform USO.

v2:
- Remove inline keyword from write_eo_udp_wr() in sge.c. Let the
  compiler decide.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>

1 files changed, 112 insertions, 47 deletions

diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c
index 5ad54493f825..53f9a821c29f 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c
@@ -734,6 +734,8 @@ static inline int is_eth_imm(const struct sk_buff *skb, unsigned int chip_ver)
 	    chip_ver > CHELSIO_T5) {
 		hdrlen = sizeof(struct cpl_tx_tnl_lso);
 		hdrlen += sizeof(struct cpl_tx_pkt_core);
+	} else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
+		return 0;
 	} else {
 		hdrlen = skb_shinfo(skb)->gso_size ?
 			 sizeof(struct cpl_tx_pkt_lso_core) : 0;
@@ -775,12 +777,20 @@ static inline unsigned int calc_tx_flits(const struct sk_buff *skb,
 	 */
 	flits = sgl_len(skb_shinfo(skb)->nr_frags + 1);
 	if (skb_shinfo(skb)->gso_size) {
-		if (skb->encapsulation && chip_ver > CHELSIO_T5)
+		if (skb->encapsulation && chip_ver > CHELSIO_T5) {
 			hdrlen = sizeof(struct fw_eth_tx_pkt_wr) +
 				 sizeof(struct cpl_tx_tnl_lso);
-		else
+		} else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
+			u32 pkt_hdrlen;
+
+			pkt_hdrlen = eth_get_headlen(skb->dev, skb->data,
+						     skb_headlen(skb));
+			hdrlen = sizeof(struct fw_eth_tx_eo_wr) +
+				 round_up(pkt_hdrlen, 16);
+		} else {
 			hdrlen = sizeof(struct fw_eth_tx_pkt_wr) +
 				 sizeof(struct cpl_tx_pkt_lso_core);
+		}
 
 		hdrlen += sizeof(struct cpl_tx_pkt_core);
 		flits += (hdrlen / sizeof(__be64));
@@ -1345,6 +1355,25 @@ static inline int cxgb4_validate_skb(struct sk_buff *skb,
 	return 0;
 }
 
+static void *write_eo_udp_wr(struct sk_buff *skb, struct fw_eth_tx_eo_wr *wr,
+			     u32 hdr_len)
+{
+	wr->u.udpseg.type = FW_ETH_TX_EO_TYPE_UDPSEG;
+	wr->u.udpseg.ethlen = skb_network_offset(skb);
+	wr->u.udpseg.iplen = cpu_to_be16(skb_network_header_len(skb));
+	wr->u.udpseg.udplen = sizeof(struct udphdr);
+	wr->u.udpseg.rtplen = 0;
+	wr->u.udpseg.r4 = 0;
+	if (skb_shinfo(skb)->gso_size)
+		wr->u.udpseg.mss = cpu_to_be16(skb_shinfo(skb)->gso_size);
+	else
+		wr->u.udpseg.mss = cpu_to_be16(skb->len - hdr_len);
+	wr->u.udpseg.schedpktsize = wr->u.udpseg.mss;
+	wr->u.udpseg.plen = cpu_to_be32(skb->len - hdr_len);
+
+	return (void *)(wr + 1);
+}
+
 /**
  *	cxgb4_eth_xmit - add a packet to an Ethernet Tx queue
  *	@skb: the packet
@@ -1357,14 +1386,15 @@ static netdev_tx_t cxgb4_eth_xmit(struct sk_buff *skb, struct net_device *dev)
 	enum cpl_tx_tnl_lso_type tnl_type = TX_TNL_TYPE_OPAQUE;
 	bool ptp_enabled = is_ptp_enabled(skb, dev);
 	unsigned int last_desc, flits, ndesc;
+	u32 wr_mid, ctrl0, op, sgl_off = 0;
 	const struct skb_shared_info *ssi;
+	int len, qidx, credits, ret, left;
 	struct tx_sw_desc *sgl_sdesc;
+	struct fw_eth_tx_eo_wr *eowr;
 	struct fw_eth_tx_pkt_wr *wr;
 	struct cpl_tx_pkt_core *cpl;
-	int len, qidx, credits, ret;
 	const struct port_info *pi;
 	bool immediate = false;
-	u32 wr_mid, ctrl0, op;
 	u64 cntrl, *end, *sgl;
 	struct sge_eth_txq *q;
 	unsigned int chip_ver;
@@ -1469,13 +1499,17 @@ static netdev_tx_t cxgb4_eth_xmit(struct sk_buff *skb, struct net_device *dev)
 	}
 
 	wr = (void *)&q->q.desc[q->q.pidx];
+	eowr = (void *)&q->q.desc[q->q.pidx];
 	wr->equiq_to_len16 = htonl(wr_mid);
 	wr->r3 = cpu_to_be64(0);
-	end = (u64 *)wr + flits;
+	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
+		end = (u64 *)eowr + flits;
+	else
+		end = (u64 *)wr + flits;
 
 	len = immediate ? skb->len : 0;
 	len += sizeof(*cpl);
-	if (ssi->gso_size) {
+	if (ssi->gso_size && !(ssi->gso_type & SKB_GSO_UDP_L4)) {
 		struct cpl_tx_pkt_lso_core *lso = (void *)(wr + 1);
 		struct cpl_tx_tnl_lso *tnl_lso = (void *)(wr + 1);
 
@@ -1507,20 +1541,29 @@ static netdev_tx_t cxgb4_eth_xmit(struct sk_buff *skb, struct net_device *dev)
 			cntrl = hwcsum(adap->params.chip, skb);
 		}
 		sgl = (u64 *)(cpl + 1); /* sgl start here */
-		if (unlikely((u8 *)sgl >= (u8 *)q->q.stat)) {
-			/* If current position is already at the end of the
-			 * txq, reset the current to point to start of the queue
-			 * and update the end ptr as well.
-			 */
-			if (sgl == (u64 *)q->q.stat) {
-				int left = (u8 *)end - (u8 *)q->q.stat;
-
-				end = (void *)q->q.desc + left;
-				sgl = (void *)q->q.desc;
-			}
-		}
 		q->tso++;
 		q->tx_cso += ssi->gso_segs;
+	} else if (ssi->gso_size) {
+		u64 *start;
+		u32 hdrlen;
+
+		hdrlen = eth_get_headlen(dev, skb->data, skb_headlen(skb));
+		len += hdrlen;
+		wr->op_immdlen = cpu_to_be32(FW_WR_OP_V(FW_ETH_TX_EO_WR) |
+					     FW_ETH_TX_EO_WR_IMMDLEN_V(len));
+		cpl = write_eo_udp_wr(skb, eowr, hdrlen);
+		cntrl = hwcsum(adap->params.chip, skb);
+
+		start = (u64 *)(cpl + 1);
+		sgl = (u64 *)inline_tx_skb_header(skb, &q->q, (void *)start,
+						  hdrlen);
+		if (unlikely(start > sgl)) {
+			left = (u8 *)end - (u8 *)q->q.stat;
+			end = (void *)q->q.desc + left;
+		}
+		sgl_off = hdrlen;
+		q->uso++;
+		q->tx_cso += ssi->gso_segs;
 	} else {
 		if (ptp_enabled)
 			op = FW_PTP_TX_PKT_WR;
@@ -1537,6 +1580,16 @@ static netdev_tx_t cxgb4_eth_xmit(struct sk_buff *skb, struct net_device *dev)
 		}
 	}
 
+	if (unlikely((u8 *)sgl >= (u8 *)q->q.stat)) {
+		/* If current position is already at the end of the
+		 * txq, reset the current to point to start of the queue
+		 * and update the end ptr as well.
+		 */
+		left = (u8 *)end - (u8 *)q->q.stat;
+		end = (void *)q->q.desc + left;
+		sgl = (void *)q->q.desc;
+	}
+
 	if (skb_vlan_tag_present(skb)) {
 		q->vlan_ins++;
 		cntrl |= TXPKT_VLAN_VLD_F | TXPKT_VLAN_V(skb_vlan_tag_get(skb));
@@ -1566,7 +1619,7 @@ static netdev_tx_t cxgb4_eth_xmit(struct sk_buff *skb, struct net_device *dev)
 		cxgb4_inline_tx_skb(skb, &q->q, sgl);
 		dev_consume_skb_any(skb);
 	} else {
-		cxgb4_write_sgl(skb, &q->q, (void *)sgl, end, 0,
+		cxgb4_write_sgl(skb, &q->q, (void *)sgl, end, sgl_off,
 				sgl_sdesc->addr);
 		skb_orphan(skb);
 		sgl_sdesc->skb = skb;
@@ -2024,7 +2077,8 @@ static inline u8 ethofld_calc_tx_flits(struct adapter *adap,
 	u32 wrlen;
 
 	wrlen = sizeof(struct fw_eth_tx_eo_wr) + sizeof(struct cpl_tx_pkt_core);
-	if (skb_shinfo(skb)->gso_size)
+	if (skb_shinfo(skb)->gso_size &&
+	    !(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4))
 		wrlen += sizeof(struct cpl_tx_pkt_lso_core);
 
 	wrlen += roundup(hdr_len, 16);
@@ -2032,10 +2086,14 @@ static inline u8 ethofld_calc_tx_flits(struct adapter *adap,
 	/* Packet headers + WR + CPLs */
 	flits = DIV_ROUND_UP(wrlen, 8);
 
-	if (skb_shinfo(skb)->nr_frags > 0)
-		nsgl = sgl_len(skb_shinfo(skb)->nr_frags);
-	else if (skb->len - hdr_len)
+	if (skb_shinfo(skb)->nr_frags > 0) {
+		if (skb_headlen(skb) - hdr_len)
+			nsgl = sgl_len(skb_shinfo(skb)->nr_frags + 1);
+		else
+			nsgl = sgl_len(skb_shinfo(skb)->nr_frags);
+	} else if (skb->len - hdr_len) {
 		nsgl = sgl_len(1);
+	}
 
 	return flits + nsgl;
 }
@@ -2049,16 +2107,16 @@ static inline void *write_eo_wr(struct adapter *adap,
 	struct cpl_tx_pkt_core *cpl;
 	u32 immd_len, wrlen16;
 	bool compl = false;
+	u8 ver, proto;
+
+	ver = ip_hdr(skb)->version;
+	proto = (ver == 6) ? ipv6_hdr(skb)->nexthdr : ip_hdr(skb)->protocol;
 
 	wrlen16 = DIV_ROUND_UP(wrlen, 16);
 	immd_len = sizeof(struct cpl_tx_pkt_core);
-	if (skb_shinfo(skb)->gso_size) {
-		if (skb->encapsulation &&
-		    CHELSIO_CHIP_VERSION(adap->params.chip) > CHELSIO_T5)
-			immd_len += sizeof(struct cpl_tx_tnl_lso);
-		else
-			immd_len += sizeof(struct cpl_tx_pkt_lso_core);
-	}
+	if (skb_shinfo(skb)->gso_size &&
+	    !(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4))
+		immd_len += sizeof(struct cpl_tx_pkt_lso_core);
 	immd_len += hdr_len;
 
 	if (!eosw_txq->ncompl ||
@@ -2074,23 +2132,27 @@ static inline void *write_eo_wr(struct adapter *adap,
 	wr->equiq_to_len16 = cpu_to_be32(FW_WR_LEN16_V(wrlen16) |
 					 FW_WR_FLOWID_V(eosw_txq->hwtid));
 	wr->r3 = 0;
-	wr->u.tcpseg.type = FW_ETH_TX_EO_TYPE_TCPSEG;
-	wr->u.tcpseg.ethlen = skb_network_offset(skb);
-	wr->u.tcpseg.iplen = cpu_to_be16(skb_network_header_len(skb));
-	wr->u.tcpseg.tcplen = tcp_hdrlen(skb);
-	wr->u.tcpseg.tsclk_tsoff = 0;
-	wr->u.tcpseg.r4 = 0;
-	wr->u.tcpseg.r5 = 0;
-	wr->u.tcpseg.plen = cpu_to_be32(skb->len - hdr_len);
-
-	if (ssi->gso_size) {
-		struct cpl_tx_pkt_lso_core *lso = (void *)(wr + 1);
-
-		wr->u.tcpseg.mss = cpu_to_be16(ssi->gso_size);
-		cpl = write_tso_wr(adap, skb, lso);
+	if (proto == IPPROTO_UDP) {
+		cpl = write_eo_udp_wr(skb, wr, hdr_len);
 	} else {
-		wr->u.tcpseg.mss = cpu_to_be16(0xffff);
-		cpl = (void *)(wr + 1);
+		wr->u.tcpseg.type = FW_ETH_TX_EO_TYPE_TCPSEG;
+		wr->u.tcpseg.ethlen = skb_network_offset(skb);
+		wr->u.tcpseg.iplen = cpu_to_be16(skb_network_header_len(skb));
+		wr->u.tcpseg.tcplen = tcp_hdrlen(skb);
+		wr->u.tcpseg.tsclk_tsoff = 0;
+		wr->u.tcpseg.r4 = 0;
+		wr->u.tcpseg.r5 = 0;
+		wr->u.tcpseg.plen = cpu_to_be32(skb->len - hdr_len);
+
+		if (ssi->gso_size) {
+			struct cpl_tx_pkt_lso_core *lso = (void *)(wr + 1);
+
+			wr->u.tcpseg.mss = cpu_to_be16(ssi->gso_size);
+			cpl = write_tso_wr(adap, skb, lso);
+		} else {
+			wr->u.tcpseg.mss = cpu_to_be16(0xffff);
+			cpl = (void *)(wr + 1);
+		}
 	}
 
 	eosw_txq->cred -= wrlen16;
@@ -4312,7 +4374,10 @@ int t4_sge_alloc_eth_txq(struct adapter *adap, struct sge_eth_txq *txq,
 	txq->q.q_type = CXGB4_TXQ_ETH;
 	init_txq(adap, &txq->q, FW_EQ_ETH_CMD_EQID_G(ntohl(c.eqid_pkd)));
 	txq->txq = netdevq;
-	txq->tso = txq->tx_cso = txq->vlan_ins = 0;
+	txq->tso = 0;
+	txq->uso = 0;
+	txq->tx_cso = 0;
+	txq->vlan_ins = 0;
 	txq->mapping_err = 0;
 	txq->dbqt = dbqt;