diff --git a/cpu/cpu_arm64.go b/cpu/cpu_arm64.go index 856dae33..87dd5e30 100644 --- a/cpu/cpu_arm64.go +++ b/cpu/cpu_arm64.go @@ -39,28 +39,26 @@ func initOptions() { func archInit() { switch runtime.GOOS { - case "android", "darwin", "ios", "netbsd", "openbsd": - // Android and iOS don't seem to allow reading these registers. - // - // NetBSD: - // ID_AA64ISAR0_EL1 is a privileged register and cannot be read from EL0. - // It can be read via sysctl(3). Example for future implementers: - // https://nxr.netbsd.org/xref/src/usr.sbin/cpuctl/arch/aarch64.c + case "freebsd": + readARM64Registers() + case "linux", "netbsd": + doinit() + default: + // Most platforms don't seem to allow reading these registers. // // OpenBSD: // See https://golang.org/issue/31746 - // - // Fake the minimal features expected by - // TestARM64minimalFeatures. - ARM64.HasASIMD = true - ARM64.HasFP = true - case "linux": - doinit() - default: - readARM64Registers() + setMinimalFeatures() } } +// setMinimalFeatures fakes the minimal ARM64 features expected by +// TestARM64minimalFeatures. +func setMinimalFeatures() { + ARM64.HasASIMD = true + ARM64.HasFP = true +} + func readARM64Registers() { Initialized = true diff --git a/cpu/cpu_netbsd_arm64.go b/cpu/cpu_netbsd_arm64.go new file mode 100644 index 00000000..ebfb3fc8 --- /dev/null +++ b/cpu/cpu_netbsd_arm64.go @@ -0,0 +1,173 @@ +// Copyright 2020 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package cpu + +import ( + "syscall" + "unsafe" +) + +// Minimal copy of functionality from x/sys/unix so the cpu package can call +// sysctl without depending on x/sys/unix. + +const ( + _CTL_QUERY = -2 + + _SYSCTL_VERS_1 = 0x1000000 +) + +var _zero uintptr + +func sysctl(mib []int32, old *byte, oldlen *uintptr, new *byte, newlen uintptr) (err error) { + var _p0 unsafe.Pointer + if len(mib) > 0 { + _p0 = unsafe.Pointer(&mib[0]) + } else { + _p0 = unsafe.Pointer(&_zero) + } + _, _, errno := syscall.Syscall6( + syscall.SYS___SYSCTL, + uintptr(_p0), + uintptr(len(mib)), + uintptr(unsafe.Pointer(old)), + uintptr(unsafe.Pointer(oldlen)), + uintptr(unsafe.Pointer(new)), + uintptr(newlen)) + if errno != 0 { + return errno + } + return nil +} + +type sysctlNode struct { + Flags uint32 + Num int32 + Name [32]int8 + Ver uint32 + __rsvd uint32 + Un [16]byte + _sysctl_size [8]byte + _sysctl_func [8]byte + _sysctl_parent [8]byte + _sysctl_desc [8]byte +} + +func sysctlNodes(mib []int32) ([]sysctlNode, error) { + var olen uintptr + + // Get a list of all sysctl nodes below the given MIB by performing + // a sysctl for the given MIB with CTL_QUERY appended. + mib = append(mib, _CTL_QUERY) + qnode := sysctlNode{Flags: _SYSCTL_VERS_1} + qp := (*byte)(unsafe.Pointer(&qnode)) + sz := unsafe.Sizeof(qnode) + if err := sysctl(mib, nil, &olen, qp, sz); err != nil { + return nil, err + } + + // Now that we know the size, get the actual nodes. + nodes := make([]sysctlNode, olen/sz) + np := (*byte)(unsafe.Pointer(&nodes[0])) + if err := sysctl(mib, np, &olen, qp, sz); err != nil { + return nil, err + } + + return nodes, nil +} + +func nametomib(name string) ([]int32, error) { + // Split name into components. + var parts []string + last := 0 + for i := 0; i < len(name); i++ { + if name[i] == '.' { + parts = append(parts, name[last:i]) + last = i + 1 + } + } + parts = append(parts, name[last:]) + + mib := []int32{} + // Discover the nodes and construct the MIB OID. + for partno, part := range parts { + nodes, err := sysctlNodes(mib) + if err != nil { + return nil, err + } + for _, node := range nodes { + n := make([]byte, 0) + for i := range node.Name { + if node.Name[i] != 0 { + n = append(n, byte(node.Name[i])) + } + } + if string(n) == part { + mib = append(mib, int32(node.Num)) + break + } + } + if len(mib) != partno+1 { + return nil, err + } + } + + return mib, nil +} + +// aarch64SysctlCPUID is struct aarch64_sysctl_cpu_id from NetBSD's +type aarch64SysctlCPUID struct { + midr uint64 /* Main ID Register */ + revidr uint64 /* Revision ID Register */ + mpidr uint64 /* Multiprocessor Affinity Register */ + aa64dfr0 uint64 /* A64 Debug Feature Register 0 */ + aa64dfr1 uint64 /* A64 Debug Feature Register 1 */ + aa64isar0 uint64 /* A64 Instruction Set Attribute Register 0 */ + aa64isar1 uint64 /* A64 Instruction Set Attribute Register 1 */ + aa64mmfr0 uint64 /* A64 Memory Model Feature Register 0 */ + aa64mmfr1 uint64 /* A64 Memory Model Feature Register 1 */ + aa64mmfr2 uint64 /* A64 Memory Model Feature Register 2 */ + aa64pfr0 uint64 /* A64 Processor Feature Register 0 */ + aa64pfr1 uint64 /* A64 Processor Feature Register 1 */ + aa64zfr0 uint64 /* A64 SVE Feature ID Register 0 */ + mvfr0 uint32 /* Media and VFP Feature Register 0 */ + mvfr1 uint32 /* Media and VFP Feature Register 1 */ + mvfr2 uint32 /* Media and VFP Feature Register 2 */ + pad uint32 + clidr uint64 /* Cache Level ID Register */ + ctr uint64 /* Cache Type Register */ +} + +func sysctlCPUID(name string) (*aarch64SysctlCPUID, error) { + mib, err := nametomib(name) + if err != nil { + return nil, err + } + + out := aarch64SysctlCPUID{} + n := unsafe.Sizeof(out) + _, _, errno := syscall.Syscall6( + syscall.SYS___SYSCTL, + uintptr(unsafe.Pointer(&mib[0])), + uintptr(len(mib)), + uintptr(unsafe.Pointer(&out)), + uintptr(unsafe.Pointer(&n)), + uintptr(0), + uintptr(0)) + if errno != 0 { + return nil, errno + } + return &out, nil +} + +func doinit() { + cpuid, err := sysctlCPUID("machdep.cpu0.cpu_id") + if err != nil { + setMinimalFeatures() + return + } + parseARM64SystemRegisters(cpuid.aa64isar0, cpuid.aa64isar1, cpuid.aa64pfr0) + + Initialized = true +} diff --git a/cpu/cpu_other_arm64.go b/cpu/cpu_other_arm64.go index 3ffc4afa..16c1c409 100644 --- a/cpu/cpu_other_arm64.go +++ b/cpu/cpu_other_arm64.go @@ -2,7 +2,8 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. -// +build !linux,arm64 +// +build !linux,!netbsd +// +build arm64 package cpu