commit 9e1fd818c15d3fd2f64cf594c3abb5df0885b1e0
Author: Tobias Klauser <tklauser@distanz.ch>
Date:   Wed Jul 22 11:52:26 2020 +0200

    Add CPUInfo parsing for RISCV
    
    Currently only 64-bit RISCV is supported (GOARCH=riscv64) by the Go
    compiler, but the cpuinfo format would be the same for 32-bit RISCV.
    
    Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

---
Rebased on node-exporter 1.0.1 by laokz <zhangkai@iscas.ac.cn>

diff --git a/vendor/github.com/prometheus/procfs/cpuinfo.go b/vendor/github.com/prometheus/procfs/cpuinfo.go
index 935157e..b9fb589 100644
--- a/vendor/github.com/prometheus/procfs/cpuinfo.go
+++ b/vendor/github.com/prometheus/procfs/cpuinfo.go
@@ -407,6 +407,46 @@ func parseCPUInfoPPC(info []byte) ([]CPUInfo, error) {
 	return cpuinfo, nil
 }
 
+func parseCPUInfoRISCV(info []byte) ([]CPUInfo, error) {
+	scanner := bufio.NewScanner(bytes.NewReader(info))
+
+	firstLine := firstNonEmptyLine(scanner)
+	if !strings.HasPrefix(firstLine, "processor") || !strings.Contains(firstLine, ":") {
+		return nil, errors.New("invalid cpuinfo file: " + firstLine)
+	}
+	field := strings.SplitN(firstLine, ": ", 2)
+	v, err := strconv.ParseUint(field[1], 0, 32)
+	if err != nil {
+		return nil, err
+	}
+	firstcpu := CPUInfo{Processor: uint(v)}
+	cpuinfo := []CPUInfo{firstcpu}
+	i := 0
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		if !strings.Contains(line, ":") {
+			continue
+		}
+		field := strings.SplitN(line, ": ", 2)
+		switch strings.TrimSpace(field[0]) {
+		case "processor":
+			v, err := strconv.ParseUint(field[1], 0, 32)
+			if err != nil {
+				return nil, err
+			}
+			i = int(v)
+			cpuinfo = append(cpuinfo, CPUInfo{}) // start of the next processor
+			cpuinfo[i].Processor = uint(v)
+		case "hart":
+			cpuinfo[i].CoreID = field[1]
+		case "isa":
+			cpuinfo[i].ModelName = field[1]
+		}
+	}
+	return cpuinfo, nil
+}
+
 // firstNonEmptyLine advances the scanner to the first non-empty line
 // and returns the contents of that line
 func firstNonEmptyLine(scanner *bufio.Scanner) string {