Files
sys/cpu/cpu_openbsd_arm64.go
Chongyi Zheng 6239615695 cpu: add HPDS, LOR, PAN detection for arm64
This CL gets ID_AA64MMFR1_EL1, Memory Model Feature Register 1, and
grabs HPDS, LOR, PAN features from its bits.

Fixes golang/go#75472.

Change-Id: Ic04b109d79aceba9b3b1d3a1ea514fcf132007c5
GitHub-Last-Rev: f938ff468b
GitHub-Pull-Request: golang/sys#263
Reviewed-on: https://go-review.googlesource.com/c/sys/+/704075
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@golang.org>
2025-10-28 09:43:50 -07:00

66 lines
1.7 KiB
Go

// Copyright 2022 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 (
// From OpenBSD's sys/sysctl.h.
_CTL_MACHDEP = 7
// From OpenBSD's machine/cpu.h.
_CPU_ID_AA64ISAR0 = 2
_CPU_ID_AA64ISAR1 = 3
)
// Implemented in the runtime package (runtime/sys_openbsd3.go)
func syscall_syscall6(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err syscall.Errno)
//go:linkname syscall_syscall6 syscall.syscall6
func sysctl(mib []uint32, old *byte, oldlen *uintptr, new *byte, newlen uintptr) (err error) {
_, _, errno := syscall_syscall6(libc_sysctl_trampoline_addr, uintptr(unsafe.Pointer(&mib[0])), uintptr(len(mib)), uintptr(unsafe.Pointer(old)), uintptr(unsafe.Pointer(oldlen)), uintptr(unsafe.Pointer(new)), uintptr(newlen))
if errno != 0 {
return errno
}
return nil
}
var libc_sysctl_trampoline_addr uintptr
//go:cgo_import_dynamic libc_sysctl sysctl "libc.so"
func sysctlUint64(mib []uint32) (uint64, bool) {
var out uint64
nout := unsafe.Sizeof(out)
if err := sysctl(mib, (*byte)(unsafe.Pointer(&out)), &nout, nil, 0); err != nil {
return 0, false
}
return out, true
}
func doinit() {
setMinimalFeatures()
// Get ID_AA64ISAR0 and ID_AA64ISAR1 from sysctl.
isar0, ok := sysctlUint64([]uint32{_CTL_MACHDEP, _CPU_ID_AA64ISAR0})
if !ok {
return
}
isar1, ok := sysctlUint64([]uint32{_CTL_MACHDEP, _CPU_ID_AA64ISAR1})
if !ok {
return
}
parseARM64SystemRegisters(isar0, isar1, 0, 0)
Initialized = true
}