RDMA/core: Introduce "name_assign_type" for an IB device

The name_assign_type indicates how the name is provided. Currently
these types are supported:
- RDMA_NAME_ASSIGN_TYPE_UNKNOWN: Unknown or not set;
- RDMA_NAME_ASSIGN_TYPE_USER: Name is provided by the user; The
  user-created sub device, rxe and siw device has this type.

When filling nl device info, it is set in the new attribute
RDMA_NLDEV_ATTR_NAME_ASSIGN_TYPE. User-space tools like udev
"rdma_rename" could check this attribute to determine if this
device needs to be renamed or not.

Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Link: https://lore.kernel.org/r/522591bef9a369cc8e5dcb77787e017bffee37fe.1719837610.git.leon@kernel.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Author: MarkZhang81

drivers/infiniband/core/nldev.c

@@ -169,6 +169,7 @@ static const struct nla_policy nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
 	[RDMA_NLDEV_ATTR_DRIVER_DETAILS]	= { .type = NLA_U8 },
 	[RDMA_NLDEV_ATTR_DEV_TYPE]		= { .type = NLA_U8 },
 	[RDMA_NLDEV_ATTR_PARENT_NAME]		= { .type = NLA_NUL_STRING },
+	[RDMA_NLDEV_ATTR_NAME_ASSIGN_TYPE]	= { .type = NLA_U8 },
 };
 
 static int put_driver_name_print_type(struct sk_buff *msg, const char *name,
@@ -312,6 +313,10 @@ static int fill_dev_info(struct sk_buff *msg, struct ib_device *device)
 			   dev_name(&device->parent->dev)))
 		return -EMSGSIZE;
 
+	if (nla_put_u8(msg, RDMA_NLDEV_ATTR_NAME_ASSIGN_TYPE,
+		       device->name_assign_type))
+		return -EMSGSIZE;
+
 	/*
 	 * Link type is determined on first port and mlx4 device
 	 * which can potentially have two different link type for the same

drivers/infiniband/hw/mlx5/main.c

@@ -4198,9 +4198,10 @@ static int mlx5_ib_stage_ib_reg_init(struct mlx5_ib_dev *dev)
 {
 	const char *name;
 
-	if (dev->sub_dev_name)
+	if (dev->sub_dev_name) {
 		name = dev->sub_dev_name;
-	else if (!mlx5_lag_is_active(dev->mdev))
+		ib_mark_name_assigned_by_user(&dev->ib_dev);
+	} else if (!mlx5_lag_is_active(dev->mdev))
 		name = "mlx5_%d";
 	else
 		name = "mlx5_bond_%d";

drivers/infiniband/sw/rxe/rxe_net.c

@@ -537,6 +537,7 @@ int rxe_net_add(const char *ibdev_name, struct net_device *ndev)
 		return -ENOMEM;
 
 	rxe->ndev = ndev;
+	ib_mark_name_assigned_by_user(&rxe->ib_dev);
 
 	err = rxe_add(rxe, ndev->mtu, ibdev_name);
 	if (err) {

drivers/infiniband/sw/siw/siw_main.c

@@ -485,6 +485,7 @@ static int siw_newlink(const char *basedev_name, struct net_device *netdev)
 		else
 			sdev->state = IB_PORT_DOWN;
 
+		ib_mark_name_assigned_by_user(&sdev->base_dev);
 		rv = siw_device_register(sdev, basedev_name);
 		if (rv)
 			ib_dealloc_device(&sdev->base_dev);

include/rdma/ib_verbs.h

@@ -2794,6 +2794,8 @@ struct ib_device {
 	enum rdma_nl_dev_type type;
 	struct ib_device *parent;
 	struct list_head subdev_list;
+
+	enum rdma_nl_name_assign_type name_assign_type;
 };
 
 static inline void *rdma_zalloc_obj(struct ib_device *dev, size_t size,
@@ -4867,4 +4869,10 @@ int ib_add_sub_device(struct ib_device *parent,
  * Return 0 on success, an error code otherwise
  */
 int ib_del_sub_device_and_put(struct ib_device *sub);
+
+static inline void ib_mark_name_assigned_by_user(struct ib_device *ibdev)
+{
+	ibdev->name_assign_type = RDMA_NAME_ASSIGN_TYPE_USER;
+}
+
 #endif /* IB_VERBS_H */

include/uapi/rdma/rdma_netlink.h

@@ -572,6 +572,8 @@ enum rdma_nldev_attr {
 
 	RDMA_NLDEV_ATTR_PARENT_NAME,		/* string */
 
+	RDMA_NLDEV_ATTR_NAME_ASSIGN_TYPE,	/* u8 */
+
 	/*
 	 * Always the end
 	 */
@@ -615,4 +617,11 @@ enum rdma_nl_counter_mask {
 enum rdma_nl_dev_type {
 	RDMA_DEVICE_TYPE_SMI = 1,
 };
+
+/* RDMA device name assignment types */
+enum rdma_nl_name_assign_type {
+	RDMA_NAME_ASSIGN_TYPE_UNKNOWN = 0,
+	RDMA_NAME_ASSIGN_TYPE_USER = 1, /* Provided by user-space */
+};
+
 #endif /* _UAPI_RDMA_NETLINK_H */