diff --git a/colossalai/moe/_operation.py b/colossalai/moe/_operation.py
index f24191c16..ac422a4da 100644
--- a/colossalai/moe/_operation.py
+++ b/colossalai/moe/_operation.py
@@ -440,114 +440,3 @@ def all_to_all_uneven(
         inputs.requires_grad
     ), "Input must require grad to assure that backward is executed, otherwise it might hang the program."
     return AllToAllUneven.apply(inputs, input_split_sizes, output_split_sizes, group, overlap)
-
-
-# ===========================================================
-# This code section was modified from
-# https://github.com/microsoft/DeepSpeed/blob/3d347276ce80e1a29e777c839d1d7fabe8e5f034/deepspeed/moe/mappings.py
-
-# Copyright (c) Microsoft Corporation.
-# SPDX-License-Identifier: Apache-2.0
-
-# DeepSpeed Team
-
-# The file has been adapted from the following Megatron-LM file:
-# https://github.com/NVIDIA/Megatron-LM/blob/main/megatron/mpu/mappings.py
-# Git commit hash: 9dc3c42a84aa656f583703cf8b6b4f79f712b796
-# We retain the following copyright from the original files:
-
-# Copyright (c) 2020, NVIDIA CORPORATION.  All rights reserved.
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# TODO: used when non-moe are tp but moe are not
-
-
-def _gather_tokens(input_, dim: int, tp_group: ProcessGroup):
-    """Gather tensors and concatenate them along a dimension"""
-
-    input_ = input_.contiguous()
-    # Size and dimension.
-    rank = tp_group.rank()
-
-    tensor_list = [torch.empty_like(input_) for _ in range(tp_group.size())]
-    tensor_list[rank] = input_
-    dist.all_gather(tensor_list, input_, group=tp_group)
-
-    # Note: torch.cat already creates a contiguous tensor.
-    output = torch.cat(tensor_list, dim=dim).contiguous()
-
-    return output
-
-
-def _drop_tokens(input_, dim: int, tp_group: ProcessGroup):
-    """Divide a tensor among the tensor parallel ranks"""
-
-    total_chunks = tp_group.size()
-    this_chunk = tp_group.rank()
-    assert (
-        input_.shape[dim] % total_chunks == 0
-    ), f"input dimension {dim} ({input_.shape[dim]}) is not divisible by tensor parallel world size ({total_chunks})"
-    chunk_size = input_.shape[dim] // total_chunks
-
-    return torch.narrow(input_, dim, this_chunk * chunk_size, chunk_size)
-
-
-class _GatherTokens(torch.autograd.Function):
-    """All gather tokens among the tensor parallel ranks"""
-
-    @staticmethod
-    def forward(ctx, input_: torch.Tensor, dim: int, tp_group: ProcessGroup) -> torch.Tensor:
-        ctx.dim = dim
-        ctx.tp_group = tp_group
-        return _gather_tokens(input_, dim, tp_group)
-
-    @staticmethod
-    def backward(ctx, grad_output):
-        return _drop_tokens(grad_output, ctx.dim, ctx.tp_group), None, None
-
-
-class _DropTokens(torch.autograd.Function):
-    "Divide tokens equally among the tensor parallel ranks"
-
-    @staticmethod
-    def forward(ctx, input_: torch.Tensor, dim: int, tp_group: ProcessGroup) -> torch.Tensor:
-        ctx.dim = dim
-        ctx.tp_group = tp_group
-        return _drop_tokens(input_, dim, tp_group)
-
-    @staticmethod
-    def backward(ctx, input_: torch.Tensor) -> Tuple[torch.Tensor, None]:
-        return _gather_tokens(input_, ctx.dim, ctx.tp_group), None, None
-
-
-def gather_tokens(input_, dim: int, tp_group: ProcessGroup):
-    if tp_group.size() == 1:
-        # no tensor parallelism for non-experts
-        return input_
-    assert (
-        input_.requires_grad
-    ), "Input must require grad to assure that backward is executed, otherwise it might hang the program."
-    return _GatherTokens.apply(input_, dim, tp_group)
-
-
-def drop_tokens(input_, dim: int, tp_group: ProcessGroup):
-    if tp_group.size() == 1:
-        # no tensor parallelism for non-experts
-        return input_
-    assert (
-        input_.requires_grad
-    ), "Input must require grad to assure that backward is executed, otherwise it might hang the program."
-    return _DropTokens.apply(input_, dim, tp_group)
-
-
-# ===========================================================