RDMA/cma: Introduce and use cma_ib_acquire_dev()

When RDMA CM connect request arrives for IB transport, it already contains
device, port, netdevice (optional).

Instead of traversing all the cma devices, use the cma device already
found by the cma_find_listener() for which a listener id is provided.

iWarp devices doesn't need to derive RoCE GIDs, therefore drop RoCE
specific checks from cma_acquire_dev() and rename it to
cma_iw_acquire_dev().
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/cma.c

@@ -691,34 +691,80 @@ static int cma_acquire_dev_by_src_ip(struct rdma_id_private *id_priv)
 	return ret;
 }
 
-static int cma_acquire_dev(struct rdma_id_private *id_priv,
-			   const struct rdma_id_private *listen_id_priv)
+/**
+ * cma_ib_acquire_dev - Acquire cma device, port and SGID attribute
+ * @id_priv:		cm id to bind to cma device
+ * @listen_id_priv:	listener cm id to match against
+ * @req:		Pointer to req structure containaining incoming
+ *			request information
+ * cma_ib_acquire_dev() acquires cma device, port and SGID attribute when
+ * rdma device matches for listen_id and incoming request. It also verifies
+ * that a GID table entry is present for the source address.
+ * Returns 0 on success, or returns error code otherwise.
+ */
+static int cma_ib_acquire_dev(struct rdma_id_private *id_priv,
+			      const struct rdma_id_private *listen_id_priv,
+			      struct cma_req_info *req)
+{
+	struct rdma_dev_addr *dev_addr = &id_priv->id.route.addr.dev_addr;
+	const struct ib_gid_attr *sgid_attr;
+	enum ib_gid_type gid_type;
+	union ib_gid gid;
+
+	if (dev_addr->dev_type != ARPHRD_INFINIBAND &&
+	    id_priv->id.ps == RDMA_PS_IPOIB)
+		return -EINVAL;
+
+	if (rdma_protocol_roce(req->device, req->port))
+		rdma_ip2gid((struct sockaddr *)&id_priv->id.route.addr.src_addr,
+			    &gid);
+	else
+		memcpy(&gid, dev_addr->src_dev_addr +
+		       rdma_addr_gid_offset(dev_addr), sizeof(gid));
+
+	gid_type = listen_id_priv->cma_dev->default_gid_type[req->port - 1];
+	sgid_attr = cma_validate_port(req->device, req->port,
+				      gid_type, &gid, id_priv);
+	if (IS_ERR(sgid_attr))
+		return PTR_ERR(sgid_attr);
+
+	id_priv->id.port_num = req->port;
+	cma_bind_sgid_attr(id_priv, sgid_attr);
+	/* Need to acquire lock to protect against reader
+	 * of cma_dev->id_list such as cma_netdev_callback() and
+	 * cma_process_remove().
+	 */
+	mutex_lock(&lock);
+	cma_attach_to_dev(id_priv, listen_id_priv->cma_dev);
+	mutex_unlock(&lock);
+	return 0;
+}
+
+static int cma_iw_acquire_dev(struct rdma_id_private *id_priv,
+			      const struct rdma_id_private *listen_id_priv)
 {
 	struct rdma_dev_addr *dev_addr = &id_priv->id.route.addr.dev_addr;
 	const struct ib_gid_attr *sgid_attr;
 	struct cma_device *cma_dev;
-	union ib_gid gid, iboe_gid, *gidp;
 	enum ib_gid_type gid_type;
 	int ret = -ENODEV;
+	union ib_gid gid;
 	u8 port;
 
 	if (dev_addr->dev_type != ARPHRD_INFINIBAND &&
 	    id_priv->id.ps == RDMA_PS_IPOIB)
 		return -EINVAL;
 
-	mutex_lock(&lock);
-	rdma_ip2gid((struct sockaddr *)&id_priv->id.route.addr.src_addr,
-		    &iboe_gid);
-
 	memcpy(&gid, dev_addr->src_dev_addr +
-	       rdma_addr_gid_offset(dev_addr), sizeof gid);
+	       rdma_addr_gid_offset(dev_addr), sizeof(gid));
+
+	mutex_lock(&lock);
 
 	cma_dev = listen_id_priv->cma_dev;
 	port = listen_id_priv->id.port_num;
-	gidp = rdma_protocol_roce(cma_dev->device, port) ? &iboe_gid : &gid;
 	gid_type = listen_id_priv->gid_type;
 	sgid_attr = cma_validate_port(cma_dev->device, port,
-				      gid_type, gidp, id_priv);
+				      gid_type, &gid, id_priv);
 	if (!IS_ERR(sgid_attr)) {
 		id_priv->id.port_num = port;
 		cma_bind_sgid_attr(id_priv, sgid_attr);
@@ -732,11 +778,9 @@ static int cma_acquire_dev(struct rdma_id_private *id_priv,
 			    listen_id_priv->id.port_num == port)
 				continue;
 
-			gidp = rdma_protocol_roce(cma_dev->device, port) ?
-			       &iboe_gid : &gid;
 			gid_type = cma_dev->default_gid_type[port - 1];
 			sgid_attr = cma_validate_port(cma_dev->device, port,
-						      gid_type, gidp, id_priv);
+						      gid_type, &gid, id_priv);
 			if (!IS_ERR(sgid_attr)) {
 				id_priv->id.port_num = port;
 				cma_bind_sgid_attr(id_priv, sgid_attr);
@@ -1582,18 +1626,18 @@ static struct rdma_id_private *cma_find_listener(
 static struct rdma_id_private *
 cma_ib_id_from_event(struct ib_cm_id *cm_id,
 		     const struct ib_cm_event *ib_event,
+		     struct cma_req_info *req,
 		     struct net_device **net_dev)
 {
-	struct cma_req_info req;
 	struct rdma_bind_list *bind_list;
 	struct rdma_id_private *id_priv;
 	int err;
 
-	err = cma_save_req_info(ib_event, &req);
+	err = cma_save_req_info(ib_event, req);
 	if (err)
 		return ERR_PTR(err);
 
-	*net_dev = cma_get_net_dev(ib_event, &req);
+	*net_dev = cma_get_net_dev(ib_event, req);
 	if (IS_ERR(*net_dev)) {
 		if (PTR_ERR(*net_dev) == -EAFNOSUPPORT) {
 			/* Assuming the protocol is AF_IB */
@@ -1631,17 +1675,17 @@ cma_ib_id_from_event(struct ib_cm_id *cm_id,
 		}
 
 		if (!validate_net_dev(*net_dev,
-				 (struct sockaddr *)&req.listen_addr_storage,
-				 (struct sockaddr *)&req.src_addr_storage)) {
+				 (struct sockaddr *)&req->listen_addr_storage,
+				 (struct sockaddr *)&req->src_addr_storage)) {
 			id_priv = ERR_PTR(-EHOSTUNREACH);
 			goto err;
 		}
 	}
 
 	bind_list = cma_ps_find(*net_dev ? dev_net(*net_dev) : &init_net,
-				rdma_ps_from_service_id(req.service_id),
-				cma_port_from_service_id(req.service_id));
-	id_priv = cma_find_listener(bind_list, cm_id, ib_event, &req, *net_dev);
+				rdma_ps_from_service_id(req->service_id),
+				cma_port_from_service_id(req->service_id));
+	id_priv = cma_find_listener(bind_list, cm_id, ib_event, req, *net_dev);
 err:
 	rcu_read_unlock();
 	if (IS_ERR(id_priv) && *net_dev) {
@@ -2063,11 +2107,12 @@ static int cma_ib_req_handler(struct ib_cm_id *cm_id,
 {
 	struct rdma_id_private *listen_id, *conn_id = NULL;
 	struct rdma_cm_event event = {};
+	struct cma_req_info req = {};
 	struct net_device *net_dev;
 	u8 offset;
 	int ret;
 
-	listen_id = cma_ib_id_from_event(cm_id, ib_event, &net_dev);
+	listen_id = cma_ib_id_from_event(cm_id, ib_event, &req, &net_dev);
 	if (IS_ERR(listen_id))
 		return PTR_ERR(listen_id);
 
@@ -2100,7 +2145,7 @@ static int cma_ib_req_handler(struct ib_cm_id *cm_id,
 	}
 
 	mutex_lock_nested(&conn_id->handler_mutex, SINGLE_DEPTH_NESTING);
-	ret = cma_acquire_dev(conn_id, listen_id);
+	ret = cma_ib_acquire_dev(conn_id, listen_id, &req);
 	if (ret)
 		goto err2;
 
@@ -2296,7 +2341,7 @@ static int iw_conn_req_handler(struct iw_cm_id *cm_id,
 		goto out;
 	}
 
-	ret = cma_acquire_dev(conn_id, listen_id);
+	ret = cma_iw_acquire_dev(conn_id, listen_id);
 	if (ret) {
 		mutex_unlock(&conn_id->handler_mutex);
 		rdma_destroy_id(new_cm_id);