+/**
+ * Get the number of physical ports of given IB device.
+ *
+ * @param nl
+ * Netlink socket of the RDMA kind (NETLINK_RDMA).
+ * @param[in] name
+ * IB device name.
+ *
+ * @return
+ * A valid (nonzero) number of ports on success, 0 otherwise
+ * and rte_errno is set.
+ */
+unsigned int
+mlx5_nl_portnum(int nl, const char *name)
+{
+ uint32_t seq = random();
+ struct mlx5_nl_ifindex_data data = {
+ .name = name,
+ .ibindex = 0,
+ .ifindex = 0,
+ .portnum = 0,
+ };
+ struct nlmsghdr req = {
+ .nlmsg_len = NLMSG_LENGTH(0),
+ .nlmsg_type = RDMA_NL_GET_TYPE(RDMA_NL_NLDEV,
+ RDMA_NLDEV_CMD_GET),
+ .nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP,
+ };
+ int ret;
+
+ ret = mlx5_nl_send(nl, &req, seq);
+ if (ret < 0)
+ return 0;
+ ret = mlx5_nl_recv(nl, seq, mlx5_nl_cmdget_cb, &data);
+ if (ret < 0)
+ return 0;
+ if (!data.ibindex) {
+ rte_errno = ENODEV;
+ return 0;
+ }
+ if (!data.portnum)
+ rte_errno = EINVAL;
+ return data.portnum;
+}
+