From 9d6e2ff1b08d121f31dc2af87c0f7688ee9bdfe6 Mon Sep 17 00:00:00 2001
From: Evan Lezar <elezar@nvidia.com>
Date: Wed, 26 Oct 2022 12:35:24 +0200
Subject: [PATCH] Add internal proc package for processing GPU information
 files

Signed-off-by: Evan Lezar <elezar@nvidia.com>
---
 internal/info/proc/information_files.go | 89 +++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 internal/info/proc/information_files.go

diff --git a/internal/info/proc/information_files.go b/internal/info/proc/information_files.go
new file mode 100644
index 00000000..dde77416
--- /dev/null
+++ b/internal/info/proc/information_files.go
@@ -0,0 +1,89 @@
+/**
+# 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 proc
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// GPUInfoField represents the field name for information specified in a GPU's information file
+type GPUInfoField string
+
+// The following constants define the fields of interest from the GPU information file
+const (
+	GPUInfoModel       = GPUInfoField("Model")
+	GPUInfoGPUUUID     = GPUInfoField("GPU UUID")
+	GPUInfoBusLocation = GPUInfoField("Bus Location")
+	GPUInfoDeviceMinor = GPUInfoField("Device Minor")
+)
+
+// GPUInfo stores the information for a GPU as determined from its associated information file
+type GPUInfo map[GPUInfoField]string
+
+// GetInformationFilePaths returns the list of information files associated with NVIDIA GPUs.
+func GetInformationFilePaths(root string) ([]string, error) {
+	return filepath.Glob(filepath.Join(root, "/proc/driver/nvidia/gpus/*/information"))
+}
+
+// ParseGPUInformationFile parses the specified GPU information file and constructs a GPUInfo structure
+func ParseGPUInformationFile(path string) (GPUInfo, error) {
+	infoFile, err := os.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open %v: %v", path, err)
+	}
+	defer infoFile.Close()
+
+	return gpuInfoFrom(infoFile), nil
+}
+
+// gpuInfoFrom parses a GPUInfo struct from the specified reader
+// An information file has the following strucutre:
+// $ cat /proc/driver/nvidia/gpus/0000\:06\:00.0/information
+// Model:           Tesla V100-SXM2-16GB
+// IRQ:             408
+// GPU UUID:        GPU-edfee158-11c1-52b8-0517-92f30e7fac88
+// Video BIOS:      88.00.41.00.01
+// Bus Type:        PCIe
+// DMA Size:        47 bits
+// DMA Mask:        0x7fffffffffff
+// Bus Location:    0000:06:00.0
+// Device Minor:    0
+// GPU Excluded:    No
+func gpuInfoFrom(reader io.Reader) GPUInfo {
+	info := make(GPUInfo)
+	scanner := bufio.NewScanner(reader)
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		parts := strings.SplitN(line, ":", 2)
+		if len(parts) != 2 {
+			continue
+		}
+
+		field := GPUInfoField(parts[0])
+		value := strings.TrimSpace(parts[1])
+
+		info[field] = value
+	}
+
+	return info
+}