support c16 prompt_cache in fa3

Author: lizhenyun01

custom_ops/gpu_ops/append_attn/gqa_rope_write_cache.cu

@@ -16,7 +16,6 @@
 #include "paddle/extension.h"
 #include "paddle/phi/core/memory/memcpy.h"
 #include "encoder_write_cache_with_rope_impl.cuh"
-#include "paddle/phi/kernels/gpu/flash_attn_v3_kernel.h"
 #include "paddle/phi/backends/context_pool.h"
 #include "remote_cache_kv_ipc.h"
 
@@ -148,6 +147,181 @@ void gqa_rotary_qk_split_variable(
             dim_head);
 }
 
+template <typename T,
+          typename CacheT,
+          uint32_t HEAD_DIM,
+          uint32_t BLOCK_SIZE,
+          uint32_t NUM_WARPS=4>
+__global__ void append_dequant_cache_kv_c16(
+    const T *__restrict__ cache_k,
+    const T *__restrict__ cache_v,
+    T *__restrict__ k_out,
+    T *__restrict__ v_out,
+    const int *__restrict__ seq_lens_this_time,
+    const int *__restrict__ seq_lens_decoder,
+    const int *__restrict__ cu_seqlens_k,
+    const int *__restrict__ block_tables,
+    const int *batch_ids,
+    const int *tile_ids_per_batch,
+    const int max_blocks_per_seq,
+    const int kv_num_heads) {
+  // start_kv_idx: 每个block的起始kv_idx
+  // batch_id：每个block属于的batch
+  // TODO: 1.scale预取 2.frag_dq_T复用 3.流水线编排 4.store访存合并 5.cacheT支持（int8/fp8)
+  const uint32_t tile_idx = blockIdx.x, kv_head_idx = blockIdx.z;
+  const uint32_t tid = threadIdx.x, wid = threadIdx.y;
+
+  const uint32_t batch_id = batch_ids[tile_idx];
+  const uint32_t start_kv_idx = tile_ids_per_batch[tile_idx] * BLOCK_SIZE;
+  const uint32_t end_idx = seq_lens_decoder[batch_id] - start_kv_idx;
+  if (seq_lens_this_time <= 0) {
+    return;
+  }
+
+  const int *cur_block_table = block_tables + batch_id * max_blocks_per_seq;
+  uint32_t block_id = cur_block_table[start_kv_idx / BLOCK_SIZE];
+  // cache_kv idx
+  uint32_t kv_h_stride = BLOCK_SIZE * HEAD_DIM;
+  uint32_t block_stride = kv_num_heads * kv_h_stride;
+  const CacheT *cur_cache_k = cache_k + block_id * block_stride + kv_head_idx * kv_h_stride;
+  const CacheT *cur_cache_v = cache_v + block_id * block_stride + kv_head_idx * kv_h_stride;
+
+  // k_out v_out idx
+  uint32_t kv_t_stride = kv_num_heads * HEAD_DIM;
+  T *k_write_ptr = k_out + (cu_seqlens_k[batch_id] + start_kv_idx) * kv_t_stride; // 当前k block起始指针
+  T *v_write_ptr = v_out + (cu_seqlens_k[batch_id] + start_kv_idx) * kv_t_stride; // 当前v block起始指针
+
+  uint32_t kv_frag[4];
+  T *frag_dq_T = reinterpret_cast<T *>(kv_frag);
+
+  constexpr uint32_t num_vecs_per_head =
+      HEAD_DIM / num_elems_per_128b<CacheT>();
+  constexpr uint32_t inv_kv_stride = 8 / num_vecs_per_head;
+
+  extern __shared__ uint8_t smem[];
+  smem_t k_smem(smem);
+  uint32_t k_smem_offset_w = smem_t::get_permuted_offset<num_vecs_per_head, inv_kv_stride>(
+      wid * 4 + tid / 8, tid % 8);  // 4 * 4 per warp
+
+  uint32_t k_smem_offset_r = smem_t::get_permuted_offset<num_vecs_per_head, inv_kv_stride>(
+      wid * 16 + 8 * (tid / 16) + tid % 8, (tid % 16) / 8);
+
+  uint32_t k_read_idx = (wid * 4 + tid / 8) * HEAD_DIM +
+                          tid % 8 * num_elems_per_128b<CacheT>();
+
+  // load k_smem 行是64 列是128
+  for (int fz = 0; fz < 4; fz++) { // 每个warp1次4行,循环4次16行,4个warp64行
+    for (int fy = 0; fy < 2; fy++) { // 一次8个128b = 64个bf16
+      k_smem.load_128b_async<SharedMemFillMode::kNoFill>(
+            k_smem_offset_w, cur_cache_k + k_read_idx, end_idx > 0);
+      k_smem_offset_w =
+            k_smem.advance_offset_by_column<8, num_vecs_per_head>(k_smem_offset_w, fy);
+      k_read_idx += 8 * num_elems_per_128b<CacheT>();
+    }
+    k_smem_offset_w =
+          k_smem.advance_offset_by_row<4 * NUM_WARPS, num_vecs_per_head>(k_smem_offset_w) - 8;
+    k_read_idx += 4 * NUM_WARPS * HEAD_DIM - 8 * num_elems_per_128b<CacheT>();
+  }
+  commit_group();
+  wait_group<0>();
+  __syncthreads();
+
+  // deal k_smem 行是64 列是128
+  for (int fz = 0; fz < 1; fz++) { // 每个warp1次16行,4个warp64行
+    uint32_t row_idx = wid * 16 + tid / 4;
+    for (int fy = 0; fy < 8; fy++) { // 1次2个128b(16个bf16),8次循环16个128b（128个bf16）
+      uint32_t col_idx = fy * 16 + tid % 4 * 2;
+      k_smem.ldmatrix_m8n8x4(k_smem_offset_r, kv_frag);
+      // 存储
+      /***
+        r0c0,r0c1, r0c8,r0c9
+        r8c0,r8c1, r8c8,r8c9
+      ***/
+      T *k_tile_ptr0 = k_write_ptr + row_idx * kv_t_stride + kv_head_idx * HEAD_DIM + col_idx;
+      T *k_tile_ptr1 = k_tile_ptr0 + 8 * kv_t_stride;
+
+      if (row_idx < end_idx) {
+        k_tile_ptr0[0] = frag_dq_T[0];
+        k_tile_ptr0[1] = frag_dq_T[1];
+        k_tile_ptr0[8] = frag_dq_T[4];
+        k_tile_ptr0[9] = frag_dq_T[5];
+      }
+
+      if (row_idx + 8 < end_idx) {
+        k_tile_ptr1[0] = frag_dq_T[2];
+        k_tile_ptr1[1] = frag_dq_T[3];
+        k_tile_ptr0[8] = frag_dq_T[6];
+        k_tile_ptr0[9] = frag_dq_T[7];
+      }
+      k_smem_offset_r = k_smem.advance_offset_by_column<2, num_vecs_per_head>(
+        k_smem_offset_r, fy);
+    }
+    k_smem_offset_r =
+      k_smem.advance_offset_by_row<16 * NUM_WARPS, num_vecs_per_head>(k_smem_offset_r) - 16;
+  }
+  // ================v================
+  smem_t v_smem(smem + BLOCK_SIZE * HEAD_DIM * sizeof(CacheT));
+  uint32_t v_smem_offset_w = smem_t::get_permuted_offset<num_vecs_per_head, inv_kv_stride>(
+      wid * 4 + tid / 8, tid % 8);  // 4 * 4 per warp
+  uint32_t v_smem_offset_r = smem_t::get_permuted_offset<num_vecs_per_head, inv_kv_stride>(
+      wid * 16 + 8 * (tid / 16) + tid % 8, (tid % 16) / 8);
+
+  uint32_t v_read_idx = (wid * 4 + tid / 8) * HEAD_DIM +
+                          tid % 8 * num_elems_per_128b<CacheT>();
+
+  // load v_smem 行是64 列是128
+  for (int fz = 0; fz < 4; fz++) { // 每个warp1次4行,循环4次16行,4个warp64行
+    for (int fy = 0; fy < 2; fy++) { // 一次8个128b = 64个bf16
+      v_smem.load_128b_async<SharedMemFillMode::kNoFill>(
+            v_smem_offset_w, cur_cache_v + v_read_idx, end_idx > 0);
+      v_smem_offset_w =
+            v_smem.advance_offset_by_column<8, num_vecs_per_head>(v_smem_offset_w, fy);
+      v_read_idx += 8 * num_elems_per_128b<CacheT>();
+    }
+    v_smem_offset_w =
+          v_smem.advance_offset_by_row<4 * NUM_WARPS, num_vecs_per_head>(v_smem_offset_w) - 8;
+    v_read_idx += 4 * NUM_WARPS * HEAD_DIM - 8 * num_elems_per_128b<CacheT>();
+  }
+  commit_group();
+  wait_group<0>();
+  __syncthreads();
+
+  // deal v_smem 行是64 列是128
+
+  for (int fz = 0; fz < 1; fz++) { // 每个warp1次16行,4个warp64行
+    uint32_t row_idx = wid * 16 + tid / 4;
+    for (int fy = 0; fy < 8; fy++) { // 1次2个128b(16个bf16),8次循环16个128b（128个bf16）
+      uint32_t col_idx = fy * 16 + tid % 4 * 2;
+      v_smem.ldmatrix_m8n8x4(v_smem_offset_r, kv_frag);
+      // 存储
+      /***
+        r0c0,r0c1, r0c8,r0c9
+        r8c0,r8c1, r8c8,r8c9
+      ***/
+      T *v_tile_ptr0 = v_write_ptr + row_idx * kv_t_stride + kv_head_idx * HEAD_DIM + col_idx;
+      T *v_tile_ptr1 = v_tile_ptr0 + 8 * kv_t_stride;
+
+      if (row_idx < end_idx) {
+        v_tile_ptr0[0] = frag_dq_T[0];
+        v_tile_ptr0[1] = frag_dq_T[1];
+        v_tile_ptr0[8] = frag_dq_T[4];
+        v_tile_ptr0[9] = frag_dq_T[5];
+      }
+
+      if (row_idx + 8 < end_idx) {
+        v_tile_ptr1[0] = frag_dq_T[2];
+        v_tile_ptr1[1] = frag_dq_T[3];
+        v_tile_ptr0[8] = frag_dq_T[6];
+        v_tile_ptr0[9] = frag_dq_T[7];
+      }
+      v_smem_offset_r = v_smem.advance_offset_by_column<2, num_vecs_per_head>(
+        v_smem_offset_r, fy);
+    }
+    v_smem_offset_r =
+      v_smem.advance_offset_by_row<16 * NUM_WARPS, num_vecs_per_head>(v_smem_offset_r) - 16;
+  }
+}
+
 template <typename T,
           typename CacheT,
           uint32_t HEAD_DIM,
@@ -214,7 +388,7 @@ __global__ void append_dequant_cache_kv_c8(
 
   uint32_t k_smem_offset_r = smem_t::get_permuted_offset<num_vecs_per_head_k, inv_k_stride>(
       wid * 16 + 8 * (tid / 16) + tid % 8, (tid % 16) / 8);
-  
+
   uint32_t k_read_idx = (wid * 4 + tid / 8) * HEAD_DIM +
                           tid % 8 * num_elems_per_128b<CacheT>();
 
@@ -328,7 +502,7 @@ __global__ void append_dequant_cache_kv_c8(
           v_tile_ptr0[8 * kv_t_stride] = frag_dq_T[2] * cache_v_scale;
           v_tile_ptr0[9 * kv_t_stride] = frag_dq_T[3] * cache_v_scale;
 
-          
+
           convert_c8<T,IS_FP8>(frag_dq_T + 4, v_frag[2 * i + 1]); // 4个uint8/fp8 -> 4个T
 #ifdef C8_DEBUG
           if (tid == 0 && wid == 0 && tile_idx == 0 && kv_head_idx == 0) {
@@ -371,14 +545,36 @@ void AppendDequantCache(
   paddle::Tensor *k_out,
   paddle::Tensor *v_out,
   const cudaStream_t& stream
-) {  
+) {
   using NV_TYPE = typename cascade_attn_type_traits<T>::type;
-  if (cache_quant_type == "cache_int8" || cache_quant_type == "cache_fp8") {
-    constexpr int NUM_WARPS = 4;
-    int block_num = cache_num_blocks_x.data<int>()[0];
-    dim3 grids(block_num, 1, kv_num_heads);
-    dim3 blocks(32, NUM_WARPS);
-    
+  constexpr int NUM_WARPS = 4;
+  int block_num = cache_num_blocks_x.data<int>()[0];
+  dim3 grids(block_num, 1, kv_num_heads);
+  dim3 blocks(32, NUM_WARPS);
+  if (cache_quant_type == "none") {
+    const uint32_t smem_size = BLOCK_SIZE * HEAD_DIM * sizeof(T) * 2;
+    auto kernel_func = append_dequant_cache_kv_c16<NV_TYPE, NV_TYPE, HEAD_DIM, BLOCK_SIZE, NUM_WARPS>;
+
+    if (smem_size >= 48 * 1024) {
+      cudaFuncSetAttribute(kernel_func,
+                          cudaFuncAttributeMaxDynamicSharedMemorySize,
+                          smem_size);
+    }
+    kernel_func<<<grids, blocks, smem_size, stream>>>(
+          reinterpret_cast<NV_TYPE *>(const_cast<T *>(cache_k.data<T>())),
+          reinterpret_cast<NV_TYPE *>(const_cast<T *>(cache_v.data<T>())),
+          reinterpret_cast<NV_TYPE *>(k_out->data<T>()),
+          reinterpret_cast<NV_TYPE *>(v_out->data<T>()),
+          seq_lens_this_time.data<int>(),
+          seq_lens_decoder.data<int>(),
+          cu_seqlens_k.data<int>(),
+          block_tables.data<int>(),
+          cache_batch_ids.data<int>(),
+          cache_tile_ids_per_batch.data<int>(),
+          max_blocks_per_seq,
+          kv_num_heads
+    );
+  } else if (cache_quant_type == "cache_int8" || cache_quant_type == "cache_fp8") {
     const uint32_t smem_size = BLOCK_SIZE * HEAD_DIM * sizeof(uint8_t) * 2;
 
     auto kernel_func = append_dequant_cache_kv_c8<NV_TYPE, uint8_t, HEAD_DIM, BLOCK_SIZE, NUM_WARPS, false>;