Files
AstrAI/csrc/kernels/attention/common.h
T
ViperEkura 16a55bb474 refactor: reorganize CUDA kernels into per-family directories
- move attention kernels to csrc/kernels/attention/ and rotary to rotary/
- add shared common/mma.cuh (mma_sync, ldmatrix) and device.cuh (sm checks)
- split fp8_mm into three-layer fp8/common.h, gemm.cuh, mm.cu
- fix fused FP8 GEMM ldmatrix lane indexing to fix OOB shared reads
- update extension ops, loader, and kernel tests
2026-08-22 20:40:31 +08:00

78 lines
2.4 KiB
C++

#pragma once
// Tensor layout for Q/K/V tensors passed to attention kernels.
// Internally, kernels always operate on BHLD [batch, n_heads, seq_len, head_dim].
// When the caller passes BLHD, dims 1 and 2 are transposed at entry.
enum TensorLayout : int {
BHLD = 0, // [batch, n_heads, seq_len, head_dim]
BLHD = 1, // [batch, seq_len, n_heads, head_dim]
};
// Unified attention params covering BOTH addressing modes:
// - Contiguous K/V: dense [batch, kv_head, kv_len, head_dim] tensors (k/v).
// - Paged (SGLang-style): flat pool [size, kv_head, head_dim] + req_to_token.
// Each kernel selects the addressing via a KVSource policy (see
// layout_policies.cuh); a given call only touches the fields of one mode, so
// this is a POD shared by both paths rather than two parallel structs that
// drift out of sync.
template<typename T, typename AT = float>
struct AttentionParams {
// Shape
int batch;
int q_head;
int kv_head;
int head_dim;
int q_len; // Per-request in contiguous mode; total_q in paged mode.
int kv_len; // Contiguous mode; paged mode uses kv_indptr.
// Attention behavior
float scale;
// -1 = non-causal; >=0 = absolute position of first Q token
int causal_offset;
int use_mask;
// pointers
const T* __restrict__ q_ptr;
const T* __restrict__ k_ptr;
const T* __restrict__ v_ptr;
const T* __restrict__ new_k_ptr;
const T* __restrict__ new_v_ptr;
T* __restrict__ o_ptr;
const bool* __restrict__ mask;
// strides
int q_b_stride;
int q_h_stride;
int q_l_stride;
int q_d_stride;
int kv_b_stride;
int kv_h_stride;
int kv_l_stride;
int kv_d_stride;
int new_kv_b_stride;
int new_kv_h_stride;
int mask_b_stride;
int mask_h_stride;
int mask_l_stride;
// Paged K/V addressing
const int* __restrict__ req_to_token; // [num_reqs, max_context_len]
const int* __restrict__ req_pool_indices; // [batch]
const int* __restrict__ kv_indptr; // [batch + 1]
const int* __restrict__ qo_indptr; // [batch + 1] or nullptr for decode
const int* __restrict__ q_tile_to_batch; // [num_q_tiles], prefill only
const int* __restrict__ q_tile_to_index; // [num_q_tiles], prefill only
int num_q_tiles;
int max_context_len; // req_to_token stride (dim 1)
// Decode split-KV workspace
int num_splits;
AT* __restrict__ o_part;
AT* __restrict__ ml_part;
};