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
This commit is contained in:
2026-08-22 20:40:31 +08:00
parent cb21af38ba
commit 16a55bb474
30 changed files with 1956 additions and 1235 deletions
+358
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@@ -0,0 +1,358 @@
#pragma once
#include <float.h>
#include <torch/extension.h>
#include <c10/cuda/CUDAGuard.h>
#include "common.h"
#include "warp_utils.cuh"
using bf16 = __nv_bfloat16;
// Dispatch head_dim: shared macro — avoids C++20 lambda template syntax.
// Usage: DISPATCH_HEAD_DIM(hd, fn, args...)
// Expands to: fn<32>(args...); fn<64>(args...); etc.
#define DISPATCH_HEAD_DIM(hd, fn, ...) \
switch (hd) { \
case 32: fn<32>(__VA_ARGS__); break; \
case 64: fn<64>(__VA_ARGS__); break; \
case 128: fn<128>(__VA_ARGS__); break; \
case 256: fn<256>(__VA_ARGS__); break; \
default: \
TORCH_CHECK(false, "unsupported head_dim ", hd, \
" (supported: 32, 64, 128, 256)"); \
}
// The split kernel unconditionally writes every (batch, q_head, split) slot it
// owns — including empty split ranges, which store m = -FLT_MAX so the combine
// skips them. Allocators are therefore left uninitialized (torch::empty); the
// per-call memset (torch::zeros / torch::full) was pure overhead.
template<typename P>
inline void alloc_split_partials(P& p) {
auto fopt = torch::TensorOptions().dtype(torch::kFloat32).device(torch::kCUDA);
auto o_part = torch::empty(at::IntArrayRef{p.batch, p.q_head, MAX_SPLITS, p.head_dim}, fopt);
auto ml_part = torch::empty(at::IntArrayRef{p.batch, p.q_head, MAX_SPLITS, 2}, fopt);
p.o_part = (float*)o_part.data_ptr();
p.ml_part = (float*)ml_part.data_ptr();
}
// ---- Shared Q-dims + strides extraction ----
template <typename P>
inline void extract_q_dims_and_strides(torch::Tensor& q, int64_t layout, P& p) {
if (layout == BLHD) q = q.transpose(1, 2);
p.batch = (int)q.size(0);
p.q_head = (int)q.size(1);
p.q_len = (int)q.size(2);
p.head_dim = (int)q.size(3);
p.q_b_stride = (int)q.stride(0);
p.q_h_stride = (int)q.stride(1);
p.q_l_stride = (int)q.stride(2);
p.q_d_stride = (int)q.stride(3);
}
// ---- Shared mask packing ----
// Accepts 2D [batch, kv_len], 3D [batch, q_len, kv_len],
// or 4D [batch, n_heads, q_len, kv_len].
// Head/q dimensions with size 1 broadcast (stride set to 0).
template <typename P>
inline void pack_mask(const c10::optional<torch::Tensor>& mask, P& p) {
if (p.use_mask) {
auto m = mask.value();
TORCH_CHECK(m.is_cuda(), "mask must be on CUDA");
TORCH_CHECK(m.dtype() == torch::kBool, "mask must be bool");
TORCH_CHECK(m.size(0) == p.batch, "mask batch mismatch");
TORCH_CHECK(m.size(m.dim() - 1) == p.kv_len, "mask kv_len mismatch");
if (m.dim() == 2) {
p.mask_b_stride = (int)m.stride(0);
p.mask_h_stride = 0;
p.mask_l_stride = 0;
} else if (m.dim() == 3) {
TORCH_CHECK(m.size(1) == 1 || m.size(1) == p.q_len, "mask q_len mismatch");
p.mask_b_stride = (int)m.stride(0);
p.mask_h_stride = 0;
p.mask_l_stride = (m.size(1) == 1) ? 0 : (int)m.stride(1);
} else if (m.dim() == 4) {
TORCH_CHECK(m.size(2) == 1 || m.size(2) == p.q_len, "mask q_len mismatch");
p.mask_b_stride = (int)m.stride(0);
p.mask_h_stride = (m.size(1) == 1) ? 0 : (int)m.stride(1);
p.mask_l_stride = (m.size(2) == 1) ? 0 : (int)m.stride(2);
} else {
TORCH_CHECK(false, "mask must be 2D, 3D, or 4D");
}
p.mask = m.data_ptr<bool>();
} else {
p.mask = nullptr;
p.mask_b_stride = 0;
p.mask_h_stride = 0;
p.mask_l_stride = 0;
}
}
// ---- attn_pack_params (contiguous KV) ----
template<typename T>
inline void attn_pack_params(
torch::Tensor q,
torch::Tensor k,
torch::Tensor v,
c10::optional<torch::Tensor> mask,
int64_t causal_offset,
double scale,
int64_t layout,
AttentionParams<T>& p
) {
const at::cuda::OptionalCUDAGuard device_guard(device_of(q));
TORCH_CHECK(q.is_cuda() && k.is_cuda() && v.is_cuda());
TORCH_CHECK(q.dtype() == torch::kBFloat16);
TORCH_CHECK(k.dtype() == torch::kBFloat16);
TORCH_CHECK(v.dtype() == torch::kBFloat16);
TORCH_CHECK(k.sizes() == v.sizes(), "K and V must have identical shapes");
TORCH_CHECK(q.dim() == 4 && k.dim() == 4, "Q/K/V must be 4D");
extract_q_dims_and_strides(q, layout, p);
if (layout == BLHD) k = k.transpose(1, 2), v = v.transpose(1, 2);
p.kv_head = (int)k.size(1);
p.kv_len = (int)k.size(2);
TORCH_CHECK(p.q_head % p.kv_head == 0,
"q_head must be divisible by kv_head");
TORCH_CHECK(k.size(3) == p.head_dim, "K/V head_dim must match Q");
TORCH_CHECK(q.stride(3) == 1 && k.stride(3) == 1 && v.stride(3) == 1,
"Q/K/V head_dim must be contiguous");
p.kv_b_stride = (int)k.stride(0);
p.kv_h_stride = (int)k.stride(1);
p.kv_l_stride = (int)k.stride(2);
p.kv_d_stride = (int)k.stride(3);
p.causal_offset = (int)causal_offset;
p.use_mask = mask.has_value() ? 1 : 0;
p.scale = (scale > 0.0) ? (float)scale : 1.0f / sqrtf((float)p.head_dim);
p.q_ptr = (const T*)q.data_ptr();
p.k_ptr = (const T*)k.data_ptr();
p.v_ptr = (const T*)v.data_ptr();
p.new_k_ptr = nullptr;
p.new_v_ptr = nullptr;
p.o_ptr = nullptr;
p.o_part = nullptr;
p.ml_part = nullptr;
pack_mask(mask, p);
}
// ---- attn_pack_paged_decode_params ----
// SGLang-style: flat KV pool + req_to_token indexing + variable
// seq_lens via kv_indptr. Q is [batch, q_head, head_dim] (q_len=1 per req).
template<typename T>
inline void attn_pack_paged_decode_params(
torch::Tensor q,
torch::Tensor k_cache,
torch::Tensor v_cache,
torch::Tensor req_to_token,
torch::Tensor req_pool_indices,
torch::Tensor kv_indptr,
const c10::optional<torch::Tensor>& new_k,
const c10::optional<torch::Tensor>& new_v,
c10::optional<torch::Tensor> mask,
int64_t causal_offset,
double scale,
AttentionParams<T>& p
) {
const at::cuda::OptionalCUDAGuard device_guard(device_of(q));
TORCH_CHECK(q.is_cuda() && k_cache.is_cuda() && v_cache.is_cuda());
TORCH_CHECK(req_to_token.is_cuda() && req_pool_indices.is_cuda() && kv_indptr.is_cuda());
TORCH_CHECK(q.dtype() == torch::kBFloat16, "q must be bf16");
TORCH_CHECK(k_cache.dtype() == torch::kBFloat16, "k_cache must be bf16");
TORCH_CHECK(v_cache.dtype() == torch::kBFloat16, "v_cache must be bf16");
TORCH_CHECK(req_to_token.dtype() == torch::kInt32, "req_to_token must be int32");
TORCH_CHECK(req_pool_indices.dtype() == torch::kInt32,
"req_pool_indices must be int32");
TORCH_CHECK(kv_indptr.dtype() == torch::kInt32, "kv_indptr must be int32");
TORCH_CHECK(k_cache.sizes() == v_cache.sizes(), "k_cache and v_cache must match");
TORCH_CHECK(k_cache.dim() == 3, "k_cache must be 3D [size, kv_head, head_dim]");
TORCH_CHECK(q.dim() == 3, "q must be 3D [batch, q_head, head_dim]");
p.batch = (int)q.size(0);
p.q_head = (int)q.size(1);
p.head_dim = (int)q.size(2);
p.kv_head = (int)k_cache.size(1);
TORCH_CHECK(k_cache.size(2) == p.head_dim, "k_cache head_dim mismatch");
TORCH_CHECK(q.stride(2) == 1 && k_cache.stride(2) == 1 && v_cache.stride(2) == 1,
"Q/K/V head_dim must be contiguous");
TORCH_CHECK(p.head_dim % 32 == 0, "head_dim must be multiple of 32");
TORCH_CHECK(p.q_head % p.kv_head == 0, "q_head must be divisible by kv_head");
p.q_l_stride = (int)q.stride(0);
p.q_h_stride = (int)q.stride(1);
p.q_d_stride = (int)q.stride(2);
p.k_ptr = (const T*)k_cache.data_ptr();
p.v_ptr = (const T*)v_cache.data_ptr();
p.q_ptr = (const T*)q.data_ptr();
p.req_to_token = req_to_token.data_ptr<int>();
p.req_pool_indices = req_pool_indices.data_ptr<int>();
p.kv_indptr = kv_indptr.data_ptr<int>();
p.qo_indptr = nullptr;
p.max_context_len = (int)req_to_token.size(1);
TORCH_CHECK(new_k.has_value() == new_v.has_value(),
"new_k and new_v must be provided together");
if (new_k.has_value()) {
auto nk = new_k.value();
auto nv = new_v.value();
TORCH_CHECK(nk.is_cuda() && nv.is_cuda(), "new K/V must be CUDA tensors");
TORCH_CHECK(nk.dtype() == torch::kBFloat16 && nv.dtype() == torch::kBFloat16,
"new K/V must be bf16");
TORCH_CHECK(nk.dim() == 3 && nv.dim() == 3,
"new K/V must be 3D [batch, kv_head, head_dim]");
TORCH_CHECK(nk.sizes() == nv.sizes(), "new K and V must have identical shapes");
TORCH_CHECK(nk.strides() == nv.strides(),
"new K and V must have identical strides");
TORCH_CHECK(nk.size(0) == p.batch && nk.size(1) == p.kv_head
&& nk.size(2) == p.head_dim, "new K/V shape mismatch");
TORCH_CHECK(nk.stride(2) == 1 && nv.stride(2) == 1,
"new K/V head_dim must be contiguous");
p.new_k_ptr = (const T*)nk.data_ptr();
p.new_v_ptr = (const T*)nv.data_ptr();
p.new_kv_b_stride = (int)nk.stride(0);
p.new_kv_h_stride = (int)nk.stride(1);
} else {
p.new_k_ptr = nullptr;
p.new_v_ptr = nullptr;
p.new_kv_b_stride = p.new_kv_h_stride = 0;
}
p.causal_offset = (int)causal_offset;
p.use_mask = (mask.has_value() && mask.value().defined()) ? 1 : 0;
p.scale = (scale > 0.0) ? (float)scale : 1.0f / sqrtf((float)p.head_dim);
if (p.use_mask) {
auto m = mask.value();
TORCH_CHECK(m.is_cuda() && m.dtype() == torch::kBool, "mask must be bool CUDA");
TORCH_CHECK(m.size(0) == p.batch, "mask batch mismatch");
p.mask_b_stride = (int)m.stride(0);
p.mask_h_stride = 0;
p.mask_l_stride = 0;
p.mask = m.data_ptr<bool>();
} else {
p.mask = nullptr;
p.mask_b_stride = 0;
p.mask_h_stride = 0;
p.mask_l_stride = 0;
}
p.o_ptr = nullptr;
p.o_part = nullptr;
p.ml_part = nullptr;
}
// ---- attn_pack_paged_prefill_params ----
// SGLang-style: flat KV pool + req_to_token + ragged batch via qo_indptr.
// Q is [total_q, q_head, head_dim] (flattened across all requests).
template<typename T>
inline void attn_pack_paged_prefill_params(
torch::Tensor q,
torch::Tensor k_cache,
torch::Tensor v_cache,
torch::Tensor req_to_token,
torch::Tensor req_pool_indices,
torch::Tensor kv_indptr,
torch::Tensor qo_indptr,
torch::Tensor q_tile_to_batch,
torch::Tensor q_tile_to_index,
c10::optional<torch::Tensor> mask,
int64_t causal_offset,
double scale,
AttentionParams<T>& p
) {
const at::cuda::OptionalCUDAGuard device_guard(device_of(q));
TORCH_CHECK(q.is_cuda() && k_cache.is_cuda() && v_cache.is_cuda());
TORCH_CHECK(req_to_token.is_cuda() && req_pool_indices.is_cuda());
TORCH_CHECK(kv_indptr.is_cuda() && qo_indptr.is_cuda());
TORCH_CHECK(q_tile_to_batch.is_cuda() && q_tile_to_index.is_cuda());
TORCH_CHECK(q.dtype() == torch::kBFloat16, "q must be bf16");
TORCH_CHECK(k_cache.dtype() == torch::kBFloat16, "k_cache must be bf16");
TORCH_CHECK(v_cache.dtype() == torch::kBFloat16, "v_cache must be bf16");
TORCH_CHECK(req_to_token.dtype() == torch::kInt32, "req_to_token must be int32");
TORCH_CHECK(req_pool_indices.dtype() == torch::kInt32,
"req_pool_indices must be int32");
TORCH_CHECK(kv_indptr.dtype() == torch::kInt32, "kv_indptr must be int32");
TORCH_CHECK(qo_indptr.dtype() == torch::kInt32, "qo_indptr must be int32");
TORCH_CHECK(q_tile_to_batch.dtype() == torch::kInt32,
"q_tile_to_batch must be int32");
TORCH_CHECK(q_tile_to_index.dtype() == torch::kInt32,
"q_tile_to_index must be int32");
TORCH_CHECK(k_cache.sizes() == v_cache.sizes(), "k_cache and v_cache must match");
TORCH_CHECK(k_cache.dim() == 3, "k_cache must be 3D [size, kv_head, head_dim]");
TORCH_CHECK(q.dim() == 3, "q must be 3D [total_q, q_head, head_dim]");
p.q_head = (int)q.size(1);
p.head_dim = (int)q.size(2);
p.q_len = (int)q.size(0);
p.kv_head = (int)k_cache.size(1);
p.batch = (int)req_pool_indices.size(0);
TORCH_CHECK(k_cache.size(2) == p.head_dim, "k_cache head_dim mismatch");
TORCH_CHECK(q.stride(2) == 1 && k_cache.stride(2) == 1 && v_cache.stride(2) == 1,
"Q/K/V head_dim must be contiguous");
TORCH_CHECK(p.head_dim % 16 == 0, "head_dim must be multiple of 16");
TORCH_CHECK(p.q_head % p.kv_head == 0, "q_head must be divisible by kv_head");
TORCH_CHECK(kv_indptr.size(0) == p.batch + 1, "kv_indptr must be [batch+1]");
TORCH_CHECK(qo_indptr.size(0) == p.batch + 1, "qo_indptr must be [batch+1]");
TORCH_CHECK(q_tile_to_batch.dim() == 1 && q_tile_to_index.dim() == 1,
"Q tile mappings must be 1D");
TORCH_CHECK(q_tile_to_batch.size(0) == q_tile_to_index.size(0),
"Q tile mappings must have equal length");
p.q_l_stride = (int)q.stride(0);
p.q_h_stride = (int)q.stride(1);
p.q_d_stride = (int)q.stride(2);
p.k_ptr = (const T*)k_cache.data_ptr();
p.v_ptr = (const T*)v_cache.data_ptr();
p.new_k_ptr = nullptr;
p.new_v_ptr = nullptr;
p.q_ptr = (const T*)q.data_ptr();
p.req_to_token = req_to_token.data_ptr<int>();
p.req_pool_indices = req_pool_indices.data_ptr<int>();
p.kv_indptr = kv_indptr.data_ptr<int>();
p.qo_indptr = qo_indptr.data_ptr<int>();
p.q_tile_to_batch = q_tile_to_batch.data_ptr<int>();
p.q_tile_to_index = q_tile_to_index.data_ptr<int>();
p.num_q_tiles = (int)q_tile_to_batch.size(0);
p.max_context_len = (int)req_to_token.size(1);
p.causal_offset = (int)causal_offset;
p.use_mask = (mask.has_value() && mask.value().defined()) ? 1 : 0;
if (p.use_mask) {
auto m = mask.value();
TORCH_CHECK(m.is_cuda() && m.dtype() == torch::kBool, "mask must be bool CUDA");
TORCH_CHECK(m.size(0) == p.batch, "mask batch mismatch");
if (m.dim() == 2) {
TORCH_CHECK(m.size(1) <= p.max_context_len, "mask kv_len mismatch");
p.mask_b_stride = (int)m.stride(0);
p.mask_h_stride = 0;
p.mask_l_stride = 0;
} else if (m.dim() == 4) {
TORCH_CHECK(m.size(1) == 1 || m.size(1) == p.q_head, "mask head mismatch");
TORCH_CHECK(m.size(2) > 0 && m.size(2) <= p.q_len, "mask q_len mismatch");
TORCH_CHECK(m.size(3) <= p.max_context_len, "mask kv_len mismatch");
p.mask_b_stride = (int)m.stride(0);
p.mask_h_stride = (m.size(1) == 1) ? 0 : (int)m.stride(1);
p.mask_l_stride = (m.size(2) == 1) ? 0 : (int)m.stride(2);
} else {
TORCH_CHECK(false, "mask must be 2D or 4D");
}
p.mask = m.data_ptr<bool>();
} else {
p.mask = nullptr;
p.mask_b_stride = 0;
p.mask_h_stride = 0;
p.mask_l_stride = 0;
}
p.scale = (scale > 0.0) ? (float)scale : 1.0f / sqrtf((float)p.head_dim);
p.o_ptr = nullptr;
p.o_part = nullptr;
p.ml_part = nullptr;
}