Add CPUInfo parsing for LoongArch64 (#384)

Signed-off-by: Wenlong Zhang <zhangwenlong@loongson.cn>

cpuinfo.go

@@ -380,6 +380,42 @@ func parseCPUInfoMips(info []byte) ([]CPUInfo, error) {
 	return cpuinfo, nil
 }
 
+func parseCPUInfoLoong(info []byte) ([]CPUInfo, error) {
+	scanner := bufio.NewScanner(bytes.NewReader(info))
+	// find the first "processor" line
+	firstLine := firstNonEmptyLine(scanner)
+	if !strings.HasPrefix(firstLine, "system type") || !strings.Contains(firstLine, ":") {
+		return nil, errors.New("invalid cpuinfo file: " + firstLine)
+	}
+	field := strings.SplitN(firstLine, ": ", 2)
+	cpuinfo := []CPUInfo{}
+	systemType := field[1]
+	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)
+			cpuinfo[i].VendorID = systemType
+		case "CPU Family":
+			cpuinfo[i].CPUFamily = field[1]
+		case "Model Name":
+			cpuinfo[i].ModelName = field[1]
+		}
+	}
+	return cpuinfo, nil
+}
+
 func parseCPUInfoPPC(info []byte) ([]CPUInfo, error) {
 	scanner := bufio.NewScanner(bytes.NewReader(info))
 

cpuinfo_loong64.go

@@ -0,0 +1,19 @@
+// Copyright 2022 The Prometheus Authors
+// 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.
+
+//go:build linux
+// +build linux
+
+package procfs
+
+var parseCPUInfo = parseCPUInfoLoong

cpuinfo_others.go

@@ -11,8 +11,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//go:build linux && !386 && !amd64 && !arm && !arm64 && !mips && !mips64 && !mips64le && !mipsle && !ppc64 && !ppc64le && !riscv64 && !s390x
-// +build linux,!386,!amd64,!arm,!arm64,!mips,!mips64,!mips64le,!mipsle,!ppc64,!ppc64le,!riscv64,!s390x
+//go:build linux && !386 && !amd64 && !arm && !arm64 && !loong64 && !mips && !mips64 && !mips64le && !mipsle && !ppc64 && !ppc64le && !riscv64 && !s390x
+// +build linux,!386,!amd64,!arm,!arm64,!loong64,!mips,!mips64,!mips64le,!mipsle,!ppc64,!ppc64le,!riscv64,!s390x
 
 package procfs
 

cpuinfo_test.go

@@ -232,6 +232,70 @@ processor	: 1
 hart		: 1
 isa		: rv64imafdcsu
 mmu		: sv48
+`
+
+	cpuinfoLoong64 = `
+system type		: generic-loongson-machine
+
+processor		: 0
+package			: 0
+core			: 0
+CPU Family		: Loongson-64bit
+Model Name		: Loongson-3A5000
+CPU Revision		: 0x10
+FPU Revision		: 0x00
+CPU MHz			: 2500.00
+BogoMIPS		: 5000.00
+TLB Entries		: 2112
+Address Sizes		: 48 bits physical, 48 bits virtual
+ISA			: loongarch32 loongarch64
+Features		: cpucfg lam ual fpu complex crypto lvz
+Hardware Watchpoint	: yes, iwatch count: 0, dwatch count: 0
+
+processor		: 1
+package			: 0
+core			: 1
+CPU Family		: Loongson-64bit
+Model Name		: Loongson-3A5000
+CPU Revision		: 0x10
+FPU Revision		: 0x00
+CPU MHz			: 2500.00
+BogoMIPS		: 5000.00
+TLB Entries		: 2112
+Address Sizes		: 48 bits physical, 48 bits virtual
+ISA			: loongarch32 loongarch64
+Features		: cpucfg lam ual fpu complex crypto lvz
+Hardware Watchpoint	: yes, iwatch count: 0, dwatch count: 0
+
+processor		: 2
+package			: 0
+core			: 2
+CPU Family		: Loongson-64bit
+Model Name		: Loongson-3A5000
+CPU Revision		: 0x10
+FPU Revision		: 0x00
+CPU MHz			: 2500.00
+BogoMIPS		: 5000.00
+TLB Entries		: 2112
+Address Sizes		: 48 bits physical, 48 bits virtual
+ISA			: loongarch32 loongarch64
+Features		: cpucfg lam ual fpu complex crypto lvz
+Hardware Watchpoint	: yes, iwatch count: 0, dwatch count: 0
+
+processor		: 3
+package			: 0
+core			: 3
+CPU Family		: Loongson-64bit
+Model Name		: Loongson-3A5000
+CPU Revision		: 0x10
+FPU Revision		: 0x00
+CPU MHz			: 2500.00
+BogoMIPS		: 5000.00
+TLB Entries		: 2112
+Address Sizes		: 48 bits physical, 48 bits virtual
+ISA			: loongarch32 loongarch64
+Features		: cpucfg lam ual fpu complex crypto lvz
+Hardware Watchpoint	: yes, iwatch count: 0, dwatch count: 0
 `
 )
 
@@ -402,3 +466,16 @@ func TestCPUInfoParseRISCV64(t *testing.T) {
 		t.Errorf("want ModelName %v, have %v", want, have)
 	}
 }
+
+func TestCPUInfoParseLoong64(t *testing.T) {
+	cpuinfo, err := parseCPUInfoLoong([]byte(cpuinfoLoong64))
+	if err != nil || cpuinfo == nil {
+		t.Fatalf("unable to parse loong cpu info: %v", err)
+	}
+	if want, have := 4, len(cpuinfo); want != have {
+		t.Errorf("want number of processors %v, have %v", want, have)
+	}
+	if want, have := "Loongson-64bit", cpuinfo[1].CPUFamily; want != have {
+		t.Errorf("want CPUFamily '%v', have '%v'", want, have)
+	}
+}