add tensorrt_llm common and cutlass_extensions as 3rdparty (#3216)

Co-authored-by: BBuf <35585791+BBuf@users.noreply.github.com>

sgl-kernel/3rdparty/tensorrt_llm/common/customAllReduceUtils.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2019-2024, 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.
+ */
+
+#pragma once
+
+#include <cstddef>
+
+namespace tensorrt_llm::utils::customAllReduceUtils
+{
+
+constexpr size_t NUM_POINTERS_PER_RANK = 7;
+
+// WARNING: MUST BE KEPT IN SYNC with tensorrt_llm/plugin/plugin.py
+inline size_t getMaxRequiredWorkspaceSize(int worldSize) noexcept
+{
+    if (worldSize <= 2)
+    {
+        return 16 * 1000 * 1000;
+    }
+    return 8 * 1000 * 1000;
+}
+
+} // namespace tensorrt_llm::utils::customAllReduceUtils