IB/cma: Resolve route only while receiving CM requests

Currently CM request for RoCE follows following flow.
rdma_create_id()
rdma_resolve_addr()
rdma_resolve_route()
For RC QPs:
rdma_connect()
->cma_connect_ib()
  ->ib_send_cm_req()
    ->cm_init_av_by_path()
      ->ib_init_ah_attr_from_path()
For UD QPs:
rdma_connect()
->cma_resolve_ib_udp()
  ->ib_send_cm_sidr_req()
    ->cm_init_av_by_path()
      ->ib_init_ah_attr_from_path()

In both the flows, route is already resolved before sending CM requests.
Therefore, code is refactored to avoid resolving route second time in
ib_cm layer.
ib_init_ah_attr_from_path() is extended to resolve route when it is not
yet resolved for RoCE link layer. This is achieved by caller setting
route_resolved field in path record whenever it has route already
resolved.
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/cm.c

@@ -1543,6 +1543,8 @@ static void cm_format_paths_from_req(struct cm_req_msg *req_msg,
 		cm_req_get_primary_local_ack_timeout(req_msg);
 	primary_path->packet_life_time -= (primary_path->packet_life_time > 0);
 	primary_path->service_id = req_msg->service_id;
+	if (sa_path_is_roce(primary_path))
+		primary_path->roce.route_resolved = false;
 
 	if (cm_req_has_alt_path(req_msg)) {
 		alt_path->dgid = req_msg->alt_local_gid;
@@ -1562,6 +1564,9 @@ static void cm_format_paths_from_req(struct cm_req_msg *req_msg,
 			cm_req_get_alt_local_ack_timeout(req_msg);
 		alt_path->packet_life_time -= (alt_path->packet_life_time > 0);
 		alt_path->service_id = req_msg->service_id;
+
+		if (sa_path_is_roce(alt_path))
+			alt_path->roce.route_resolved = false;
 	}
 	cm_format_path_lid_from_req(req_msg, primary_path, alt_path);
 }

drivers/infiniband/core/cma.c

@@ -2506,6 +2506,7 @@ cma_iboe_set_path_rec_l2_fields(struct rdma_id_private *id_priv)
 		gid_type = ib_network_to_gid_type(addr->dev_addr.network);
 	route->path_rec->rec_type = sa_conv_gid_to_pathrec_type(gid_type);
 
+	route->path_rec->roce.route_resolved = true;
 	sa_path_set_ndev(route->path_rec, addr->dev_addr.net);
 	sa_path_set_ifindex(route->path_rec, ndev->ifindex);
 	sa_path_set_dmac(route->path_rec, addr->dev_addr.dst_dev_addr);

drivers/infiniband/core/sa_query.c

@@ -1248,6 +1248,9 @@ roce_resolve_route_from_path(struct ib_device *device, u8 port_num,
 	} sgid_addr, dgid_addr;
 	int ret;
 
+	if (rec->roce.route_resolved)
+		return 0;
+
 	if (!device->get_netdev)
 		return -EOPNOTSUPP;
 
@@ -1287,6 +1290,8 @@ roce_resolve_route_from_path(struct ib_device *device, u8 port_num,
 		dev_put(ndev);
 done:
 	dev_put(idev);
+	if (!ret)
+		rec->roce.route_resolved = true;
 	return ret;
 }
 

include/rdma/ib_sa.h

@@ -163,7 +163,15 @@ struct sa_path_rec_ib {
 	u8           raw_traffic;
 };
 
+/**
+ * struct sa_path_rec_roce - RoCE specific portion of the path record entry
+ * @route_resolved:	When set, it indicates that this route is already
+ *			resolved for this path record entry.
+ * @dmac:		Destination mac address for the given DGID entry
+ *			of the path record entry.
+ */
 struct sa_path_rec_roce {
+	bool	route_resolved;
 	u8           dmac[ETH_ALEN];
 	/* ignored in IB */
 	int	     ifindex;