Add internal drm package for determining DRM devices

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

internal/info/drm/drm_devices.go

@@ -0,0 +1,39 @@
+/**
+# 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 drm
+
+import (
+	"fmt"
+	"path/filepath"
+)
+
+// GetDeviceNodesByBusID returns the DRM devices associated with the specified PCI bus ID
+func GetDeviceNodesByBusID(busID string) ([]string, error) {
+	drmRoot := filepath.Join("/sys/bus/pci/devices", busID, "drm")
+	matches, err := filepath.Glob(fmt.Sprintf("%s/*", drmRoot))
+	if err != nil {
+		return nil, err
+	}
+
+	var drmDeviceNodes []string
+	for _, m := range matches {
+		drmDeviceNode := filepath.Join("/dev/dri", filepath.Base(m))
+		drmDeviceNodes = append(drmDeviceNodes, drmDeviceNode)
+	}
+
+	return drmDeviceNodes, nil
+}