IB/mlx5: Expose correct max_fast_reg_page_list_len

While documentation indicates that the number of translation
entries per memory key is unlimited, in practice, we can
only fit a finite amount of translation entries in a single
registration wqe (which is log_max_klm_list_size).
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx5/main.c

@@ -539,7 +539,8 @@ static int mlx5_ib_query_device(struct ib_device *ibdev,
 	props->local_ca_ack_delay  = MLX5_CAP_GEN(mdev, local_ca_ack_delay);
 	props->max_res_rd_atom	   = props->max_qp_rd_atom * props->max_qp;
 	props->max_srq_sge	   = max_rq_sg - 1;
-	props->max_fast_reg_page_list_len = (unsigned int)-1;
+	props->max_fast_reg_page_list_len =
+		1 << MLX5_CAP_GEN(mdev, log_max_klm_list_size);
 	get_atomic_caps(dev, props);
 	props->masked_atomic_cap   = IB_ATOMIC_NONE;
 	props->max_mcast_grp	   = 1 << MLX5_CAP_GEN(mdev, log_max_mcg);