Add CUDA ComputeCapability function

Signed-off-by: Evan Lezar <elezar@nvidia.com>

internal/cuda/cuda.go

@@ -31,11 +31,21 @@ import (
 #define CUDAAPI
 #endif
 
+typedef int CUdevice;
+
+typedef enum CUdevice_attribute_enum {
+    CU_DEVICE_ATTRIBUTE_COMPUTE_CAPABILITY_MAJOR = 75,
+    CU_DEVICE_ATTRIBUTE_COMPUTE_CAPABILITY_MINOR = 76
+} CUdevice_attribute;
+
 typedef enum cudaError_enum {
 	CUDA_SUCCESS = 0
 } CUresult;
 
+CUresult CUDAAPI cuInit(unsigned int Flags);
 CUresult CUDAAPI cuDriverGetVersion(int *driverVersion);
+CUresult CUDAAPI cuDeviceGet(CUdevice *device, int ordinal);
+CUresult CUDAAPI cuDeviceGetAttribute(int *pi, CUdevice_attribute attrib, CUdevice dev);
 */
 import "C"
 
@@ -71,6 +81,48 @@ func Version() (string, error) {
 	return fmt.Sprintf("%d.%d", major, minor), nil
 }
 
+// ComputeCapability returns the CUDA compute capability of a device with the specified index as a string
+// or an error if this cannot be determined.
+func ComputeCapability(index int) (string, error) {
+	lib, err := load()
+	if err != nil {
+		return "", err
+	}
+	defer lib.Close()
+
+	if err := lib.Lookup("cuInit"); err != nil {
+		return "", fmt.Errorf("failed to lookup symbol: %v", err)
+	}
+	if err := lib.Lookup("cuDeviceGet"); err != nil {
+		return "", fmt.Errorf("failed to lookup symbol: %v", err)
+	}
+	if err := lib.Lookup("cuDeviceGetAttribute"); err != nil {
+		return "", fmt.Errorf("failed to lookup symbol: %v", err)
+	}
+
+	if result := C.cuInit(C.uint(0)); result != C.CUDA_SUCCESS {
+		return "", fmt.Errorf("failed to initialize CUDA: result=%v", result)
+	}
+
+	var device C.CUdevice
+	// NOTE: We only query the first device
+	if result := C.cuDeviceGet(&device, C.int(index)); result != C.CUDA_SUCCESS {
+		return "", fmt.Errorf("failed to get CUDA device %v: result=%v", 0, result)
+	}
+
+	var major C.int
+	if result := C.cuDeviceGetAttribute(&major, C.CU_DEVICE_ATTRIBUTE_COMPUTE_CAPABILITY_MAJOR, device); result != C.CUDA_SUCCESS {
+		return "", fmt.Errorf("failed to get CUDA compute capability major for device %v : result=%v", 0, result)
+	}
+
+	var minor C.int
+	if result := C.cuDeviceGetAttribute(&minor, C.CU_DEVICE_ATTRIBUTE_COMPUTE_CAPABILITY_MINOR, device); result != C.CUDA_SUCCESS {
+		return "", fmt.Errorf("failed to get CUDA compute capability minor for device %v: result=%v", 0, result)
+	}
+
+	return fmt.Sprintf("%d.%d", major, minor), nil
+}
+
 func load() (*dl.DynamicLibrary, error) {
 	lib := dl.New(libraryName, libraryLoadFlags)
 	if lib == nil {