From a672713dba9fe4cd1671a02c614f57ed86498c8d Mon Sep 17 00:00:00 2001
From: Evan Lezar <elezar@nvidia.com>
Date: Fri, 29 Apr 2022 14:38:13 +0200
Subject: [PATCH] Add basic CUDA wrapper

Signed-off-by: Evan Lezar <elezar@nvidia.com>
---
 internal/cuda/cuda.go | 85 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)
 create mode 100644 internal/cuda/cuda.go

diff --git a/internal/cuda/cuda.go b/internal/cuda/cuda.go
new file mode 100644
index 00000000..6224de3e
--- /dev/null
+++ b/internal/cuda/cuda.go
@@ -0,0 +1,85 @@
+/**
+# Copyright (c) 2022, NVIDIA CORPORATION.  All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+**/
+
+package cuda
+
+import (
+	"fmt"
+
+	"github.com/NVIDIA/go-nvml/pkg/dl"
+)
+
+/*
+#cgo LDFLAGS: -Wl,--unresolved-symbols=ignore-in-object-files
+
+#ifdef _WIN32
+#define CUDAAPI __stdcall
+#else
+#define CUDAAPI
+#endif
+
+typedef enum cudaError_enum {
+	CUDA_SUCCESS = 0
+} CUresult;
+
+CUresult CUDAAPI cuDriverGetVersion(int *driverVersion);
+*/
+import "C"
+
+const (
+	libraryName      = "libcuda.so.1"
+	libraryLoadFlags = dl.RTLD_LAZY | dl.RTLD_GLOBAL
+)
+
+// cuda stores a reference the cuda dynamic library
+var lib *dl.DynamicLibrary
+
+// Version returns the CUDA version of the driver as a string or an error if this
+// cannot be determined.
+func Version() (string, error) {
+	lib, err := load()
+	if err != nil {
+		return "", err
+	}
+	defer lib.Close()
+
+	if err := lib.Lookup("cuDriverGetVersion"); err != nil {
+		return "", fmt.Errorf("failed to lookup symbol: %v", err)
+	}
+
+	var version C.int
+	if result := C.cuDriverGetVersion(&version); result != C.CUDA_SUCCESS {
+		return "", fmt.Errorf("failed to get CUDA version: result=%v", result)
+	}
+
+	major := version / 1000
+	minor := version % 100 / 10
+
+	return fmt.Sprintf("%d.%d", major, minor), nil
+}
+
+func load() (*dl.DynamicLibrary, error) {
+	lib := dl.New(libraryName, libraryLoadFlags)
+	if lib == nil {
+		return nil, fmt.Errorf("error instantiating DynamicLibrary for CUDA")
+	}
+	err := lib.Open()
+	if err != nil {
+		return nil, fmt.Errorf("error opening DynamicLibrary for CUDA: %v", err)
+	}
+
+	return lib, nil
+}