RDMA/cxgb4: Add support for MPAv2 Enhanced RDMA Negotiation

This patch adds support for Enhanced RDMA Connection Establishment
(draft-ietf-storm-mpa-peer-connect-06), aka MPAv2.  Details of draft
can be obtained from:
<http://www.ietf.org/id/draft-ietf-storm-mpa-peer-connect-06.txt>

The patch updates the following functions for initiator perspective:
 - send_mpa_request
 - process_mpa_reply
 - post_terminate for TERM error codes
 - destroy_qp for TERM related change
 - adds layer/etype/ecode to c4iw_qp_attrs for sending with TERM
 - peer_abort for retrying connection attempt with MPA_v1 message
 - added c4iw_reconnect function

The patch updates the following functions for responder perspective:
 - process_mpa_request
 - send_mpa_reply
 - c4iw_accept_cr
 - passes ird/ord to upper layers
Signed-off-by: Kumar Sanghvi <kumaras@chelsio.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/cxgb4/iw_cxgb4.h

@@ -323,6 +323,7 @@ struct c4iw_mpa_attributes {
 	u8 recv_marker_enabled;
 	u8 xmit_marker_enabled;
 	u8 crc_enabled;
+	u8 enhanced_rdma_conn;
 	u8 version;
 	u8 p2p_type;
 };
@@ -349,6 +350,8 @@ struct c4iw_qp_attributes {
 	u8 is_terminate_local;
 	struct c4iw_mpa_attributes mpa_attr;
 	struct c4iw_ep *llp_stream_handle;
+	u8 layer_etype;
+	u8 ecode;
 };
 
 struct c4iw_qp {
@@ -501,11 +504,18 @@ enum c4iw_mmid_state {
 #define MPA_KEY_REP "MPA ID Rep Frame"
 
 #define MPA_MAX_PRIVATE_DATA	256
+#define MPA_ENHANCED_RDMA_CONN	0x10
 #define MPA_REJECT		0x20
 #define MPA_CRC			0x40
 #define MPA_MARKERS		0x80
 #define MPA_FLAGS_MASK		0xE0
 
+#define MPA_V2_PEER2PEER_MODEL          0x8000
+#define MPA_V2_ZERO_LEN_FPDU_RTR        0x4000
+#define MPA_V2_RDMA_WRITE_RTR           0x8000
+#define MPA_V2_RDMA_READ_RTR            0x4000
+#define MPA_V2_IRD_ORD_MASK             0x3FFF
+
 #define c4iw_put_ep(ep) { \
 	PDBG("put_ep (via %s:%u) ep %p refcnt %d\n", __func__, __LINE__,  \
 	     ep, atomic_read(&((ep)->kref.refcount))); \
@@ -528,6 +538,11 @@ struct mpa_message {
 	u8 private_data[0];
 };
 
+struct mpa_v2_conn_params {
+	__be16 ird;
+	__be16 ord;
+};
+
 struct terminate_message {
 	u8 layer_etype;
 	u8 ecode;
@@ -580,7 +595,10 @@ enum c4iw_ddp_ecodes {
 
 enum c4iw_mpa_ecodes {
 	MPA_CRC_ERR		= 0x02,
-	MPA_MARKER_ERR		= 0x03
+	MPA_MARKER_ERR          = 0x03,
+	MPA_LOCAL_CATA          = 0x05,
+	MPA_INSUFF_IRD          = 0x06,
+	MPA_NOMATCH_RTR         = 0x07,
 };
 
 enum c4iw_ep_state {
@@ -651,6 +669,8 @@ struct c4iw_ep {
 	u16 txq_idx;
 	u16 ctrlq_idx;
 	u8 tos;
+	u8 retry_with_mpa_v1;
+	u8 tried_with_mpa_v1;
 };
 
 static inline struct c4iw_ep *to_ep(struct iw_cm_id *cm_id)

drivers/infiniband/hw/cxgb4/qp.c

@@ -917,6 +917,10 @@ static void post_terminate(struct c4iw_qp *qhp, struct t4_cqe *err_cqe,
 	wqe->u.terminate.type = FW_RI_TYPE_TERMINATE;
 	wqe->u.terminate.immdlen = cpu_to_be32(sizeof *term);
 	term = (struct terminate_message *)wqe->u.terminate.termmsg;
+	if (qhp->attr.layer_etype == (LAYER_MPA|DDP_LLP)) {
+		term->layer_etype = qhp->attr.layer_etype;
+		term->ecode = qhp->attr.ecode;
+	} else
 		build_term_codes(err_cqe, &term->layer_etype, &term->ecode);
 	c4iw_ofld_send(&qhp->rhp->rdev, skb);
 }
@@ -1012,6 +1016,7 @@ static int rdma_fini(struct c4iw_dev *rhp, struct c4iw_qp *qhp,
 
 static void build_rtr_msg(u8 p2p_type, struct fw_ri_init *init)
 {
+	PDBG("%s p2p_type = %d\n", __func__, p2p_type);
 	memset(&init->u, 0, sizeof init->u);
 	switch (p2p_type) {
 	case FW_RI_INIT_P2PTYPE_RDMA_WRITE:
@@ -1212,6 +1217,8 @@ int c4iw_modify_qp(struct c4iw_dev *rhp, struct c4iw_qp *qhp,
 			break;
 		case C4IW_QP_STATE_TERMINATE:
 			set_state(qhp, C4IW_QP_STATE_TERMINATE);
+			qhp->attr.layer_etype = attrs->layer_etype;
+			qhp->attr.ecode = attrs->ecode;
 			if (qhp->ibqp.uobject)
 				t4_set_wq_in_error(&qhp->wq);
 			ep = qhp->ep;
@@ -1334,6 +1341,9 @@ int c4iw_destroy_qp(struct ib_qp *ib_qp)
 	rhp = qhp->rhp;
 
 	attrs.next_state = C4IW_QP_STATE_ERROR;
+	if (qhp->attr.state == C4IW_QP_STATE_TERMINATE)
+		c4iw_modify_qp(rhp, qhp, C4IW_QP_ATTR_NEXT_STATE, &attrs, 1);
+	else
 		c4iw_modify_qp(rhp, qhp, C4IW_QP_ATTR_NEXT_STATE, &attrs, 0);
 	wait_event(qhp->wait, !qhp->ep);