IB/core: Introduce and use sgid_attr in CM requests

For RoCE, when CM requests are received for RC and UD connections,
netdevice of the incoming request is unavailable. Because of that CM
requests are always forwarded to init_net namespace.

Now that we have the GID attribute available, introduce SGID attribute in
incoming CM requests and refer to the netdevice of it.  This is similar to
existing SGID attribute field in outgoing CM requests for RC and UD
transports.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/cm.c

@@ -1716,6 +1716,7 @@ static void cm_format_req_event(struct cm_work *work,
 	param->retry_count = cm_req_get_retry_count(req_msg);
 	param->rnr_retry_count = cm_req_get_rnr_retry_count(req_msg);
 	param->srq = cm_req_get_srq(req_msg);
+	param->ppath_sgid_attr = cm_id_priv->av.ah_attr.grh.sgid_attr;
 	work->cm_event.private_data = &req_msg->private_data;
 }
 
@@ -3532,6 +3533,7 @@ out:
 EXPORT_SYMBOL(ib_send_cm_sidr_req);
 
 static void cm_format_sidr_req_event(struct cm_work *work,
+				     const struct cm_id_private *rx_cm_id,
 				     struct ib_cm_id *listen_id)
 {
 	struct cm_sidr_req_msg *sidr_req_msg;
@@ -3545,6 +3547,7 @@ static void cm_format_sidr_req_event(struct cm_work *work,
 	param->service_id = sidr_req_msg->service_id;
 	param->bth_pkey = cm_get_bth_pkey(work);
 	param->port = work->port->port_num;
+	param->sgid_attr = rx_cm_id->av.ah_attr.grh.sgid_attr;
 	work->cm_event.private_data = &sidr_req_msg->private_data;
 }
 
@@ -3602,7 +3605,7 @@ static int cm_sidr_req_handler(struct cm_work *work)
 	cm_id_priv->id.service_id = sidr_req_msg->service_id;
 	cm_id_priv->id.service_mask = ~cpu_to_be64(0);
 
-	cm_format_sidr_req_event(work, &cur_cm_id_priv->id);
+	cm_format_sidr_req_event(work, cm_id_priv, &cur_cm_id_priv->id);
 	cm_process_work(cm_id_priv, work);
 	cm_deref_id(cur_cm_id_priv);
 	return 0;

drivers/infiniband/core/cma.c

@@ -1371,6 +1371,22 @@ static bool validate_net_dev(struct net_device *net_dev,
 	}
 }
 
+static struct net_device *
+roce_get_net_dev_by_cm_event(const struct ib_cm_event *ib_event)
+{
+	const struct ib_gid_attr *sgid_attr = NULL;
+
+	if (ib_event->event == IB_CM_REQ_RECEIVED)
+		sgid_attr = ib_event->param.req_rcvd.ppath_sgid_attr;
+	else if (ib_event->event == IB_CM_SIDR_REQ_RECEIVED)
+		sgid_attr = ib_event->param.sidr_req_rcvd.sgid_attr;
+
+	if (!sgid_attr)
+		return NULL;
+	dev_hold(sgid_attr->ndev);
+	return sgid_attr->ndev;
+}
+
 static struct net_device *cma_get_net_dev(struct ib_cm_event *ib_event,
 					  struct cma_req_info *req)
 {
@@ -1386,8 +1402,12 @@ static struct net_device *cma_get_net_dev(struct ib_cm_event *ib_event,
 	if (err)
 		return ERR_PTR(err);
 
-	net_dev = ib_get_net_dev_by_params(req->device, req->port, req->pkey,
-					   gid, listen_addr);
+	if (rdma_protocol_roce(req->device, req->port))
+		net_dev = roce_get_net_dev_by_cm_event(ib_event);
+	else
+		net_dev = ib_get_net_dev_by_params(req->device, req->port,
+						   req->pkey,
+						   gid, listen_addr);
 	if (!net_dev)
 		return ERR_PTR(-ENODEV);
 
@@ -1508,10 +1528,6 @@ static struct rdma_id_private *cma_id_from_event(struct ib_cm_id *cm_id,
 		if (PTR_ERR(*net_dev) == -EAFNOSUPPORT) {
 			/* Assuming the protocol is AF_IB */
 			*net_dev = NULL;
-		} else if (rdma_protocol_roce(req.device, req.port)) {
-			/* TODO find the net dev matching the request parameters
-			 * through the RoCE GID table */
-			*net_dev = NULL;
 		} else {
 			return ERR_CAST(*net_dev);
 		}

include/rdma/ib_cm.h

@@ -120,6 +120,13 @@ struct ib_cm_req_event_param {
 	struct sa_path_rec	*primary_path;
 	struct sa_path_rec	*alternate_path;
 
+	/*
+	 * SGID attribute of the primary path. Currently only
+	 * useful for RoCE. Alternate path GID attributes
+	 * are not yet supported.
+	 */
+	const struct ib_gid_attr *ppath_sgid_attr;
+
 	__be64			remote_ca_guid;
 	u32			remote_qkey;
 	u32			remote_qpn;
@@ -226,6 +233,12 @@ struct ib_cm_apr_event_param {
 struct ib_cm_sidr_req_event_param {
 	struct ib_cm_id		*listen_id;
 	__be64			service_id;
+
+	/*
+	 * SGID attribute of the request. Currently only
+	 * useful for RoCE.
+	 */
+	const struct ib_gid_attr *sgid_attr;
 	/* P_Key that was used by the GMP's BTH header */
 	u16			bth_pkey;
 	u8			port;