[cpu][linux]: add riscv cpu parser

cpu/cpu_linux.go

@@ -221,6 +221,25 @@ func InfoWithContext(ctx context.Context) ([]InfoStat, error) {
 			if strings.Contains(value, "S390") {
 				processorName = "S390"
 			}
+		case "mvendorid":
+			if !strings.HasPrefix(value, "0x") {
+				continue
+			}
+
+			if v, err := strconv.ParseUint(value[2:], 16, 32); err == nil {
+				switch v {
+				case 0x31e:
+					c.VendorID = "Andes"
+				case 0x029:
+					c.VendorID = "Microchip"
+				case 0x127:
+					c.VendorID = "MIPS"
+				case 0x489:
+					c.VendorID = "SiFive"
+				case 0x5b7:
+					c.VendorID = "T-Head"
+				}
+			}
 		case "CPU implementer":
 			if v, err := strconv.ParseUint(value, 0, 8); err == nil {
 				switch v {
@@ -256,9 +275,9 @@ func InfoWithContext(ctx context.Context) ([]InfoStat, error) {
 					c.VendorID = "Ampere"
 				}
 			}
-		case "cpu family":
+		case "cpu family", "marchid":
 			c.Family = value
-		case "model", "CPU part":
+		case "model", "CPU part", "mimpid":
 			c.Model = value
 			// if CPU is arm based, model name is found via model number. refer to: arch/arm64/kernel/cpuinfo.c
 			if c.VendorID == "ARM" {
@@ -271,7 +290,7 @@ func InfoWithContext(ctx context.Context) ([]InfoStat, error) {
 					}
 				}
 			}
-		case "Model Name", "model name", "cpu":
+		case "Model Name", "model name", "cpu", "uarch":
 			c.ModelName = value
 			if strings.Contains(value, "POWER") {
 				c.Model = strings.Split(value, " ")[0]
@@ -305,14 +324,19 @@ func InfoWithContext(ctx context.Context) ([]InfoStat, error) {
 				return ret, err
 			}
 			c.CacheSize = int32(t)
-		case "physical id":
+		case "physical id", "hart":
 			c.PhysicalID = value
 		case "core id":
 			c.CoreID = value
 		case "flags", "Features":
 			c.Flags = strings.FieldsFunc(value, func(r rune) bool {
 				return r == ',' || r == ' '
 			})
+		case "isa", "hart isa":
+			if len(c.Flags) != 0 || !strings.HasPrefix(value, "rv64") {
+				continue
+			}
+			c.Flags = riscvISAParse(value)
 		case "microcode":
 			c.Microcode = value
 		}
@@ -495,3 +519,13 @@ func CountsWithContext(ctx context.Context, logical bool) (int, error) {
 	}
 	return ret, nil
 }
+
+func riscvISAParse(s string) []string {
+	ext := strings.Split(s, "_")
+	if len(ext[0]) <= 4 {
+		return nil
+	}
+	// the base extensions must "rv64" prefix
+	base := strings.Split(ext[0][4:], "")
+	return append(base, ext[1:]...)
+}