main
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1 #pragma once
2 #include <stddef.h>
3 #include <torch/csrc/stable/tensor.h>
4 #include <torch/csrc/stable/ops.h>
5
6 #include "libtorch_stable/torch_utils.h"
7
8 // clang-format will break include orders
9 // clang-format off
10 #include "cute/tensor.hpp"
11 #include "cute/atom/mma_atom.hpp"
12 #include "cutlass/numeric_types.h"
13
14 #include "cutlass/cutlass.h"
15 #include "cutlass/gemm_coord.h"
16 #include "cutlass/arch/mma_sm75.h"
17 #include "cutlass/arch/arch.h"
18 #include "cutlass/arch/mma.h"
19 #include "cutlass/gemm/device/gemm.h"
20 #include "cutlass/gemm/device/gemm_universal_adapter.h"
21
22 #include "cutlass/epilogue/threadblock/fusion/visitors.hpp"
23 #include "cutlass/gemm/kernel/default_gemm_universal_with_visitor.h"
24
25 #include "libtorch_stable/core/math.hpp"
26 #include "libtorch_stable/cutlass_extensions/common.hpp"
27 // clang-format on
28
29 using namespace cute;
30
31 /*
32 Epilogues defined in,
33 csrc/cutlass_extensions/epilogue/scaled_mm_epilogues_c2x.hpp
34 must contain a public type named EVTCompute of type Sm80EVT,
35 as well as a static prepare_args function that constructs an
36 EVTCompute::Arguments struct.
37 */
38
39 namespace vllm {
40 template <typename Arch, template <typename> typename ArchGuard,
41 typename ElementAB_, typename ElementD_,
42 template <typename, typename> typename Epilogue_, typename TileShape,
43 typename WarpShape, typename InstructionShape, int32_t MainLoopStages,
44 typename FP8MathOperator = cutlass::arch::OpMultiplyAdd>
45 struct cutlass_2x_gemm {
46 using ElementAB = ElementAB_;
47 using ElementD = ElementD_;
48
49 using ElementAcc =
50 typename std::conditional<std::is_same_v<ElementAB, int8_t>, int32_t,
51 float>::type;
52
53 using Operator =
54 typename std::conditional<std::is_same_v<ElementAB, int8_t>,
55 cutlass::arch::OpMultiplyAddSaturate,
56 FP8MathOperator>::type;
57
58 using OutputTileThreadMap =
59 cutlass::epilogue::threadblock::OutputTileThreadLayout<
60 TileShape, WarpShape, float, 4, 1 /* epilogue stages */
61 >;
62
63 using Epilogue = Epilogue_<ElementD, OutputTileThreadMap>;
64 using EVTCompute = typename Epilogue::EVTCompute;
65
66 using D = cutlass::epilogue::threadblock::VisitorAuxStore<
67 OutputTileThreadMap, ElementD, cutlass::FloatRoundStyle::round_to_nearest,
68 Stride<int64_t, Int<1>, Int<0>>>;
69
70 using EVTD = cutlass::epilogue::threadblock::Sm80EVT<D, EVTCompute>;
71
72 // These are the minimum alignments needed for the kernels to compile
73 static constexpr int AlignmentAB =
74 128 / cutlass::sizeof_bits<ElementAB>::value;
75 static constexpr int AlignmentCD = 4;
76
77 // clang-format off
78 using RowMajor = typename cutlass::layout::RowMajor;
79 using ColumnMajor = typename cutlass::layout::ColumnMajor;
80 using KernelType =
81 ArchGuard<typename cutlass::gemm::kernel::DefaultGemmWithVisitor<
82 ElementAB, RowMajor, cutlass::ComplexTransform::kNone, AlignmentAB,
83 ElementAB, ColumnMajor, cutlass::ComplexTransform::kNone, AlignmentAB,
84 float, cutlass::layout::RowMajor, AlignmentCD,
85 ElementAcc, float, cutlass::arch::OpClassTensorOp,
86 Arch,
87 TileShape, WarpShape, InstructionShape,
88 EVTD,
89 cutlass::gemm::threadblock::ThreadblockSwizzleStreamK,
90 MainLoopStages, Operator,
91 1 /* epilogue stages */
92 >::GemmKernel>;
93 // clang-format on
94
95 using Op = cutlass::gemm::device::GemmUniversalAdapter<KernelType>;
96 };
97
98 template <typename Gemm, typename... EpilogueArgs>
99 inline void cutlass_gemm_caller(torch::stable::Tensor& out,
100 torch::stable::Tensor const& a,
101 torch::stable::Tensor const& b,
102 EpilogueArgs&&... epilogue_params) {
103 using ElementAB = typename Gemm::ElementAB;
104 using ElementD = typename Gemm::ElementD;
105
106 int32_t m = a.size(0);
107 int32_t n = b.size(1);
108 int32_t k = a.size(1);
109 cutlass::gemm::GemmCoord problem_size{m, n, k};
110
111 int64_t lda = a.stride(0);
112 int64_t ldb = b.stride(1);
113 int64_t ldc = out.stride(0);
114
115 using StrideC = Stride<int64_t, Int<1>, Int<0>>;
116 StrideC c_stride{ldc, Int<1>{}, Int<0>{}};
117
118 auto a_ptr = static_cast<ElementAB const*>(a.data_ptr());
119 auto b_ptr = static_cast<ElementAB const*>(b.data_ptr());
120 auto c_ptr = static_cast<ElementD*>(out.data_ptr());
121
122 typename Gemm::D::Arguments d_args{c_ptr, c_stride};
123
124 using Epilogue = typename Gemm::Epilogue;
125 auto evt_args =
126 Epilogue::prepare_args(std::forward<EpilogueArgs>(epilogue_params)...);
127
128 typename Gemm::EVTD::Arguments epilogue_args{
129 evt_args,
130 d_args,
131 };
132
133 typename Gemm::Op::Arguments args{
134 cutlass::gemm::GemmUniversalMode::kGemmSplitKParallel, // universal mode
135 problem_size, // problem size
136 1, // batch count
137 epilogue_args,
138 a_ptr,
139 b_ptr,
140 nullptr,
141 nullptr,
142 0,
143 0,
144 0,
145 0,
146 lda,
147 ldb,
148 ldc,
149 ldc};
150
151 // Launch the CUTLASS GEMM kernel.
152 typename Gemm::Op gemm_op;
153 size_t workspace_size = gemm_op.get_workspace_size(args);
154 auto device = a.device();
155 auto workspace =
156 torch::stable::empty(workspace_size, torch::headeronly::ScalarType::Byte,
157 std::nullopt, device);
158
159 const torch::stable::accelerator::DeviceGuard device_guard(device.index());
160 auto stream = get_current_cuda_stream(device.index());
161
162 CUTLASS_CHECK(gemm_op.can_implement(args));
163 cutlass::Status status = gemm_op(args, workspace.data_ptr(), stream);
164 CUTLASS_CHECK(status);
165 }
166
167 template <typename Gemm, typename FallbackGemm, typename... EpilogueArgs>
168 inline void fallback_cutlass_gemm_caller(torch::stable::Tensor& out,
169 torch::stable::Tensor const& a,
170 torch::stable::Tensor const& b,
171 EpilogueArgs&&... args) {
172 // In some cases, the GPU isn't able to accommodate the
173 // shared memory requirements of the Gemm. In such cases, use
174 // the FallbackGemm instead.
175 static const int max_shared_mem_per_block_opt_in =
176 get_cuda_max_shared_memory_per_block_opt_in(0);
177
178 size_t const gemm_shared_mem_size =
179 sizeof(typename Gemm::KernelType::SharedStorage);
180 size_t const fallback_gemm_shared_mem_size =
181 sizeof(typename FallbackGemm::KernelType::SharedStorage);
182
183 if (gemm_shared_mem_size <= max_shared_mem_per_block_opt_in) {
184 return cutlass_gemm_caller<Gemm>(out, a, b,
185 std::forward<EpilogueArgs>(args)...);
186 } else {
187 STD_TORCH_CHECK(fallback_gemm_shared_mem_size <=
188 max_shared_mem_per_block_opt_in);
189 return cutlass_gemm_caller<FallbackGemm>(
190 out, a, b, std::forward<EpilogueArgs>(args)...);
191 }
192 }
193
194 } // namespace vllm