Add i-cache flush for AMD GPUs into FBGEMM (#3208)

Summary:

X-link: facebookresearch/FBGEMM#307

- Add a function into FBGEMM to flush i-cache

Reviewed By: zixi-qi

Differential Revision: D63296513

fbgemm_gpu/experimental/gen_ai/src/quantize/ck_extensions/ck_utility.hip

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <cstdlib>
+#include <functional>
+#include <initializer_list>
+#include <iostream>
+#include <numeric>
+#include <tuple>
+#include <unordered_map>
+
+#include <ATen/ATen.h>
+#include <c10/hip/HIPStream.h>
+#include <torch/torch.h>
+
+#if defined(USE_ROCM)
+
+#include "ck/ck.hpp"
+#include "ck/stream_config.hpp"
+#include "ck/host_utility/hip_check_error.hpp"
+#include "ck/utility/flush_icache.hpp"
+
+namespace fbgemm_gpu {
+
+void flush_icache_ck()
+{
+    hipDeviceProp_t deviceProps;
+    hip_check_error(hipGetDeviceProperties(&deviceProps, 0));
+    int32_t gpu_block3 = deviceProps.multiProcessorCount * 60;
+
+    auto stream = at::cuda::getCurrentHIPStream().stream();
+
+    ck::flush_icache<<<dim3(gpu_block3), dim3(64), 0, stream>>>();
+    hip_check_error(hipGetLastError());
+}
+
+} // namespace fbgemm_gpu
+
+#endif // defined(USE_ROCM)

fbgemm_gpu/experimental/gen_ai/src/quantize/quantize.cpp

@@ -27,6 +27,11 @@
 
 namespace fbgemm_gpu {
 
+#ifdef USE_ROCM
+// flush icache
+void flush_icache_ck();
+#endif
+
 // SmoothQuant kernels
 at::Tensor
 i8i8bf16(at::Tensor XQ, at::Tensor WQ, double scale, int64_t split_k);
@@ -185,6 +190,11 @@ TORCH_LIBRARY_FRAGMENT(fbgemm, m) {
   m.impl(
       "quantize_fp8_per_tensor_fixed_scale",
       quantize_fp8_per_tensor_fixed_scale);
+
+#ifdef USE_ROCM
+  m.def("flush_icache_hip() -> ()");
+  m.impl("flush_icache_hip", flush_icache_ck);
+#endif
 }
 
 TORCH_LIBRARY_IMPL(fbgemm, CUDA, m) {