Files
agentic-pd-hybrid/third_party/sglang/sgl-kernel/csrc/flash_extension.cc

101 lines
4.2 KiB
C++

/* Copyright 2025 SGLang Team. 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.
==============================================================================*/
#include <ATen/core/dispatch/Dispatcher.h>
#include <torch/all.h>
#include <torch/library.h>
#include "sgl_flash_kernel_ops.h"
TORCH_LIBRARY_FRAGMENT(sgl_kernel, m) {
/*
* From flash-attention
*/
m.def(
"fwd(Tensor q," // (b, s_q, h, d) or (total_q, h, d) if there is cu_seqlens_q
" Tensor k," // (b_k, s_k, h_k, d) or (total_k, h_k, d) or paged
" Tensor v," // (b_k, s_k, h_k, dv) or (total_k, h_k, dv) or paged
" Tensor? k_new," // (b, s_k_new, h_k, d) or (total_k_new, h_k, d)
" Tensor? v_new," // (b, s_k_new, h_k, dv) or (total_k_new, h_k, dv)
" Tensor? q_v," // (b, s_q, h, dv) or (total_q_new, h, dv)
" Tensor? out," // (b, s_q, h, dv) or (total_q, h, dv)
" Tensor? cu_seqlens_q," // b+1
" Tensor? cu_seqlens_k," // b+1
" Tensor? cu_seqlens_k_new," // b+1
" Tensor? seqused_q," // b
" Tensor? seqused_k," // b
" int? max_seqlen_q,"
" int? max_seqlen_k," // TODO: check if needed
" Tensor? page_table," // (b_k, max_num_pages_per_seq)
" Tensor? kv_batch_idx," // b
" Tensor? leftpad_k," // b
" Tensor? rotary_cos," // seqlen_ro x (rotary_dim / 2)
" Tensor? rotary_sin," // seqlen_ro x (rotary_dim / 2)
" Tensor? seqlens_rotary," // b
" Tensor? q_descale," // (b, h_k)
" Tensor? k_descale," // (b, h_k)
" Tensor? v_descale," // (b, h_k)
" float? softmax_scale," // now optional
" bool is_causal,"
" int window_size_left,"
" int window_size_right,"
" int attention_chunk," // NEW
" float softcap," // promoted to double in C++; schema float is fine
" bool is_rotary_interleaved,"
" Tensor? scheduler_metadata," // (b + 1)
" int num_splits,"
" bool? pack_gqa,"
" int sm_margin,"
" Tensor? sinks"
") -> (Tensor, Tensor, Tensor, Tensor)"); // NEW return type: tuple of 4 tensors
m.impl("fwd", torch::kCUDA, make_pytorch_shim(&mha_fwd));
/*
* From flash-attention: get_scheduler_metadata
* Precomputes tile scheduling for FA3 to avoid per-layer prepare_varlen_num_blocks calls.
*/
m.def(
"get_scheduler_metadata("
" int batch_size,"
" int max_seqlen_q,"
" int max_seqlen_k,"
" int num_heads,"
" int num_heads_k,"
" int headdim,"
" int headdim_v,"
" ScalarType qkv_dtype,"
" Tensor seqused_k," // b
" Tensor? cu_seqlens_q," // b+1
" Tensor? cu_seqlens_k," // b+1
" Tensor? cu_seqlens_k_new," // b+1
" Tensor? seqused_q," // b
" Tensor? leftpad_k," // b
" int? page_size,"
" int max_seqlen_k_new = 0,"
" bool is_causal = False,"
" int window_size_left = -1,"
" int window_size_right = -1,"
" int attention_chunk = 0,"
" bool has_softcap = False,"
" int num_splits = 0,"
" bool? pack_gqa = None,"
" int sm_margin = 0"
") -> Tensor");
m.impl("get_scheduler_metadata", torch::kCUDA, make_pytorch_shim(&mha_fwd_get_scheduler_metadata));
}
REGISTER_EXTENSION(flash_ops)