support 1 shot allreduce in 1-node and 2-node using mscclpp (#6277)

sgl-kernel/python/sgl_kernel/allreduce.py

@@ -49,6 +49,27 @@ if torch.version.hip is not None:
     def get_meta_buffer_ipc_handle(inp: torch.Tensor) -> torch.Tensor:
         return torch.ops.sgl_kernel.get_meta_buffer_ipc_handle.default(inp)
 
+    def mscclpp_generate_unique_id() -> bytes:
+        raise NotImplementedError()
+
+    def mscclpp_init_context(
+        unique_id: bytes,
+        rank: int,
+        world_size: int,
+        scratch: torch.Tensor,
+        put_buffer: torch.Tensor,
+        nranks_per_node: int,
+        rank_to_node: List[int],
+        rank_to_ib: List[int],
+        context_selection: int,
+    ) -> int:
+        raise NotImplementedError()
+
+    def mscclpp_allreduce(
+        context: int, inp: torch.Tensor, out: torch.Tensor, nthreads: int, nblocks: int
+    ) -> None:
+        raise NotImplementedError()
+
 else:
 
     def init_custom_ar(
@@ -85,3 +106,36 @@ else:
 
     def meta_size() -> int:
         return torch.ops.sgl_kernel.meta_size.default()
+
+    def mscclpp_generate_unique_id() -> torch.Tensor:
+        return torch.ops.sgl_kernel.mscclpp_generate_unique_id.default()
+
+    def mscclpp_init_context(
+        unique_id: torch.Tensor,
+        rank: int,
+        world_size: int,
+        scratch: torch.Tensor,
+        put_buffer: torch.Tensor,
+        nranks_per_node: int,
+        rank_to_node: List[int],
+        rank_to_ib: List[int],
+        context_selection: int,
+    ) -> int:
+        return torch.ops.sgl_kernel.mscclpp_init_context.default(
+            unique_id,
+            rank,
+            world_size,
+            scratch,
+            put_buffer,
+            nranks_per_node,
+            rank_to_node,
+            rank_to_ib,
+            context_selection,
+        )
+
+    def mscclpp_allreduce(
+        context: int, inp: torch.Tensor, out: torch.Tensor, nthreads: int, nblocks: int
+    ) -> None:
+        torch.ops.sgl_kernel.mscclpp_allreduce.default(
+            context, inp, out, nthreads, nblocks
+        )