RDMA/cxgb4: Fix LE hash collision bug for active open connection

It enables establishing active open connection using fw_ofld_connection work
request when cpl_act_open_rpl says TCAM full error which may be because
of LE hash collision. Current support is only for IPv4 active open connections.

Sets ntuple bits in active open requests. For T4 firmware greater than 1.4.10.0
ntuple bits are required to be set.

Adds nocong and enable_ecn module parameter options.

Signed-off-by: Vipul Pandya <vipul@chelsio.com>

[ Move all FW return values to t4fw_api.h.  - Roland ]

Signed-off-by: Roland Dreier <roland@purestorage.com>

2 files changed, 153 insertions, 6 deletions

diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index 5de8696..4878704 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -61,6 +61,14 @@ static char *states[] = {
 	NULL,
 };
 
+static int nocong;
+module_param(nocong, int, 0644);
+MODULE_PARM_DESC(nocong, "Turn of congestion control (default=0)");
+
+static int enable_ecn;
+module_param(enable_ecn, int, 0644);
+MODULE_PARM_DESC(enable_ecn, "Enable ECN (default=0/disabled)");
+
 static int dack_mode = 1;
 module_param(dack_mode, int, 0644);
 MODULE_PARM_DESC(dack_mode, "Delayed ack mode (default=1)");
@@ -441,6 +449,50 @@ static int send_abort(struct c4iw_ep *ep, struct sk_buff *skb, gfp_t gfp)
 	return c4iw_l2t_send(&ep->com.dev->rdev, skb, ep->l2t);
 }
 
+#define VLAN_NONE 0xfff
+#define FILTER_SEL_VLAN_NONE 0xffff
+#define FILTER_SEL_WIDTH_P_FC (3+1) /* port uses 3 bits, FCoE one bit */
+#define FILTER_SEL_WIDTH_VIN_P_FC \
+	(6 + 7 + FILTER_SEL_WIDTH_P_FC) /* 6 bits are unused, VF uses 7 bits*/
+#define FILTER_SEL_WIDTH_TAG_P_FC \
+	(3 + FILTER_SEL_WIDTH_VIN_P_FC) /* PF uses 3 bits */
+#define FILTER_SEL_WIDTH_VLD_TAG_P_FC (1 + FILTER_SEL_WIDTH_TAG_P_FC)
+
+static unsigned int select_ntuple(struct c4iw_dev *dev, struct dst_entry *dst,
+				  struct l2t_entry *l2t)
+{
+	unsigned int ntuple = 0;
+	u32 viid;
+
+	switch (dev->rdev.lldi.filt_mode) {
+
+	/* default filter mode */
+	case HW_TPL_FR_MT_PR_IV_P_FC:
+		if (l2t->vlan == VLAN_NONE)
+			ntuple |= FILTER_SEL_VLAN_NONE << FILTER_SEL_WIDTH_P_FC;
+		else {
+			ntuple |= l2t->vlan << FILTER_SEL_WIDTH_P_FC;
+			ntuple |= 1 << FILTER_SEL_WIDTH_VLD_TAG_P_FC;
+		}
+		ntuple |= l2t->lport << S_PORT | IPPROTO_TCP <<
+			  FILTER_SEL_WIDTH_VLD_TAG_P_FC;
+		break;
+	case HW_TPL_FR_MT_PR_OV_P_FC: {
+		viid = cxgb4_port_viid(l2t->neigh->dev);
+
+		ntuple |= FW_VIID_VIN_GET(viid) << FILTER_SEL_WIDTH_P_FC;
+		ntuple |= FW_VIID_PFN_GET(viid) << FILTER_SEL_WIDTH_VIN_P_FC;
+		ntuple |= FW_VIID_VIVLD_GET(viid) << FILTER_SEL_WIDTH_TAG_P_FC;
+		ntuple |= l2t->lport << S_PORT | IPPROTO_TCP <<
+			  FILTER_SEL_WIDTH_VLD_TAG_P_FC;
+		break;
+	}
+	default:
+		break;
+	}
+	return ntuple;
+}
+
 static int send_connect(struct c4iw_ep *ep)
 {
 	struct cpl_act_open_req *req;
@@ -463,7 +515,8 @@ static int send_connect(struct c4iw_ep *ep)
 
 	cxgb4_best_mtu(ep->com.dev->rdev.lldi.mtus, ep->mtu, &mtu_idx);
 	wscale = compute_wscale(rcv_win);
-	opt0 = KEEP_ALIVE(1) |
+	opt0 = (nocong ? NO_CONG(1) : 0) |
+	       KEEP_ALIVE(1) |
 	       DELACK(1) |
 	       WND_SCALE(wscale) |
 	       MSS_IDX(mtu_idx) |
@@ -474,6 +527,7 @@ static int send_connect(struct c4iw_ep *ep)
 	       ULP_MODE(ULP_MODE_TCPDDP) |
 	       RCV_BUFSIZ(rcv_win>>10);
 	opt2 = RX_CHANNEL(0) |
+	       CCTRL_ECN(enable_ecn) |
 	       RSS_QUEUE_VALID | RSS_QUEUE(ep->rss_qid);
 	if (enable_tcp_timestamps)
 		opt2 |= TSTAMPS_EN(1);
@@ -492,7 +546,7 @@ static int send_connect(struct c4iw_ep *ep)
 	req->local_ip = ep->com.local_addr.sin_addr.s_addr;
 	req->peer_ip = ep->com.remote_addr.sin_addr.s_addr;
 	req->opt0 = cpu_to_be64(opt0);
-	req->params = 0;
+	req->params = cpu_to_be32(select_ntuple(ep->com.dev, ep->dst, ep->l2t));
 	req->opt2 = cpu_to_be32(opt2);
 	return c4iw_l2t_send(&ep->com.dev->rdev, skb, ep->l2t);
 }
@@ -1383,6 +1437,61 @@ static int abort_rpl(struct c4iw_dev *dev, struct sk_buff *skb)
 	return 0;
 }
 
+static void send_fw_act_open_req(struct c4iw_ep *ep, unsigned int atid)
+{
+	struct sk_buff *skb;
+	struct fw_ofld_connection_wr *req;
+	unsigned int mtu_idx;
+	int wscale;
+
+	skb = get_skb(NULL, sizeof(*req), GFP_KERNEL);
+	req = (struct fw_ofld_connection_wr *)__skb_put(skb, sizeof(*req));
+	memset(req, 0, sizeof(*req));
+	req->op_compl = htonl(V_WR_OP(FW_OFLD_CONNECTION_WR));
+	req->len16_pkd = htonl(FW_WR_LEN16(DIV_ROUND_UP(sizeof(*req), 16)));
+	req->le.filter = cpu_to_be32(select_ntuple(ep->com.dev, ep->dst,
+				     ep->l2t));
+	req->le.lport = ep->com.local_addr.sin_port;
+	req->le.pport = ep->com.remote_addr.sin_port;
+	req->le.u.ipv4.lip = ep->com.local_addr.sin_addr.s_addr;
+	req->le.u.ipv4.pip = ep->com.remote_addr.sin_addr.s_addr;
+	req->tcb.t_state_to_astid =
+			htonl(V_FW_OFLD_CONNECTION_WR_T_STATE(TCP_SYN_SENT) |
+			V_FW_OFLD_CONNECTION_WR_ASTID(atid));
+	req->tcb.cplrxdataack_cplpassacceptrpl =
+			htons(F_FW_OFLD_CONNECTION_WR_CPLRXDATAACK);
+	req->tcb.tx_max = jiffies;
+	cxgb4_best_mtu(ep->com.dev->rdev.lldi.mtus, ep->mtu, &mtu_idx);
+	wscale = compute_wscale(rcv_win);
+	req->tcb.opt0 = TCAM_BYPASS(1) |
+		(nocong ? NO_CONG(1) : 0) |
+		KEEP_ALIVE(1) |
+		DELACK(1) |
+		WND_SCALE(wscale) |
+		MSS_IDX(mtu_idx) |
+		L2T_IDX(ep->l2t->idx) |
+		TX_CHAN(ep->tx_chan) |
+		SMAC_SEL(ep->smac_idx) |
+		DSCP(ep->tos) |
+		ULP_MODE(ULP_MODE_TCPDDP) |
+		RCV_BUFSIZ(rcv_win >> 10);
+	req->tcb.opt2 = PACE(1) |
+		TX_QUEUE(ep->com.dev->rdev.lldi.tx_modq[ep->tx_chan]) |
+		RX_CHANNEL(0) |
+		CCTRL_ECN(enable_ecn) |
+		RSS_QUEUE_VALID | RSS_QUEUE(ep->rss_qid);
+	if (enable_tcp_timestamps)
+		req->tcb.opt2 |= TSTAMPS_EN(1);
+	if (enable_tcp_sack)
+		req->tcb.opt2 |= SACK_EN(1);
+	if (wscale && enable_tcp_window_scaling)
+		req->tcb.opt2 |= WND_SCALE_EN(1);
+	req->tcb.opt0 = cpu_to_be64(req->tcb.opt0);
+	req->tcb.opt2 = cpu_to_be32(req->tcb.opt2);
+	set_wr_txq(skb, CPL_PRIORITY_CONTROL, 0);
+	c4iw_l2t_send(&ep->com.dev->rdev, skb, ep->l2t);
+}
+
 /*
  * Return whether a failed active open has allocated a TID
  */
@@ -1419,6 +1528,14 @@ static int act_open_rpl(struct c4iw_dev *dev, struct sk_buff *skb)
 	case CPL_ERR_CONN_RESET:
 	case CPL_ERR_CONN_TIMEDOUT:
 		break;
+	case CPL_ERR_TCAM_FULL:
+		mutex_lock(&dev->rdev.stats.lock);
+		dev->rdev.stats.tcam_full++;
+		mutex_unlock(&dev->rdev.stats.lock);
+		send_fw_act_open_req(ep,
+			GET_TID_TID(GET_AOPEN_ATID(ntohl(rpl->atid_status))));
+		return 0;
+		break;
 	default:
 		printk(KERN_INFO MOD "Active open failure - "
 		       "atid %u status %u errno %d %pI4:%u->%pI4:%u\n",
@@ -1510,14 +1627,15 @@ static void accept_cr(struct c4iw_ep *ep, __be32 peer_ip, struct sk_buff *skb,
 	skb_get(skb);
 	cxgb4_best_mtu(ep->com.dev->rdev.lldi.mtus, ep->mtu, &mtu_idx);
 	wscale = compute_wscale(rcv_win);
-	opt0 = KEEP_ALIVE(1) |
+	opt0 = (nocong ? NO_CONG(1) : 0) |
+	       KEEP_ALIVE(1) |
 	       DELACK(1) |
 	       WND_SCALE(wscale) |
 	       MSS_IDX(mtu_idx) |
 	       L2T_IDX(ep->l2t->idx) |
 	       TX_CHAN(ep->tx_chan) |
 	       SMAC_SEL(ep->smac_idx) |
-	       DSCP(ep->tos) |
+	       DSCP(ep->tos >> 2) |
 	       ULP_MODE(ULP_MODE_TCPDDP) |
 	       RCV_BUFSIZ(rcv_win>>10);
 	opt2 = RX_CHANNEL(0) |
@@ -1529,6 +1647,15 @@ static void accept_cr(struct c4iw_ep *ep, __be32 peer_ip, struct sk_buff *skb,
 		opt2 |= SACK_EN(1);
 	if (wscale && enable_tcp_window_scaling)
 		opt2 |= WND_SCALE_EN(1);
+	if (enable_ecn) {
+		const struct tcphdr *tcph;
+		u32 hlen = ntohl(req->hdr_len);
+
+		tcph = (const void *)(req + 1) + G_ETH_HDR_LEN(hlen) +
+			G_IP_HDR_LEN(hlen);
+		if (tcph->ece && tcph->cwr)
+			opt2 |= CCTRL_ECN(1);
+	}
 
 	rpl = cplhdr(skb);
 	INIT_TP_WR(rpl, ep->hwtid);
@@ -2647,11 +2774,14 @@ static int fw6_msg(struct c4iw_dev *dev, struct sk_buff *skb)
 	struct cpl_fw6_msg *rpl = cplhdr(skb);
 	struct c4iw_wr_wait *wr_waitp;
 	int ret;
+	u8 opcode;
+	struct cpl_fw6_msg_ofld_connection_wr_rpl *req;
+	struct c4iw_ep *ep;
 
 	PDBG("%s type %u\n", __func__, rpl->type);
 
 	switch (rpl->type) {
-	case 1:
+	case FW6_TYPE_WR_RPL:
 		ret = (int)((be64_to_cpu(rpl->data[0]) >> 8) & 0xff);
 		wr_waitp = (struct c4iw_wr_wait *)(__force unsigned long) rpl->data[1];
 		PDBG("%s wr_waitp %p ret %u\n", __func__, wr_waitp, ret);
@@ -2659,9 +2789,25 @@ static int fw6_msg(struct c4iw_dev *dev, struct sk_buff *skb)
 			c4iw_wake_up(wr_waitp, ret ? -ret : 0);
 		kfree_skb(skb);
 		break;
-	case 2:
+	case FW6_TYPE_CQE:
 		sched(dev, skb);
 		break;
+	case FW6_TYPE_OFLD_CONNECTION_WR_RPL:
+		opcode = *(const u8 *)rpl->data;
+		if (opcode == FW_OFLD_CONNECTION_WR) {
+			req =
+			(struct cpl_fw6_msg_ofld_connection_wr_rpl *)rpl->data;
+			if (req->t_state == TCP_SYN_SENT
+			    && (req->retval == FW_ENOMEM
+				|| req->retval == FW_EADDRINUSE)) {
+				ep = (struct c4iw_ep *)
+				     lookup_atid(dev->rdev.lldi.tids,
+						 req->tid);
+				c4iw_l2t_send(&dev->rdev, skb, ep->l2t);
+				return 0;
+			}
+		}
+		break;
 	default:
 		printk(KERN_ERR MOD "%s unexpected fw6 msg type %u\n", __func__,
 		       rpl->type);
diff --git a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
index 9beb3a9..6a17fde 100644
--- a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
+++ b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
@@ -130,6 +130,7 @@ struct c4iw_stats {
 	u64  db_empty;
 	u64  db_drop;
 	u64  db_state_transitions;
+	u64  tcam_full;
 };
 
 struct c4iw_rdev {