PKGBUILD/vendor/periph.io/x/periph/host/pmem/mem_linux.go
2018-12-07 20:42:30 +01:00

57 lines
1.4 KiB
Go

// Copyright 2016 The Periph Authors. All rights reserved.
// Use of this source code is governed under the Apache License, Version 2.0
// that can be found in the LICENSE file.
package pmem
import "syscall"
const isLinux = true
func mmap(fd uintptr, offset int64, length int) ([]byte, error) {
v, err := syscall.Mmap(int(fd), offset, length, syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED)
if err != nil {
return nil, wrapf("failed to memory map: %v", err)
}
return v, nil
}
func munmap(b []byte) error {
if err := syscall.Munmap(b); err != nil {
return wrapf("failed to unmap memory: %v", err)
}
return nil
}
func mlock(b []byte) error {
if err := syscall.Mlock(b); err != nil {
return wrapf("failed to lock memory: %v", err)
}
return nil
}
func munlock(b []byte) error {
if err := syscall.Munlock(b); err != nil {
return wrapf("failed to unlock memory: %v", err)
}
return nil
}
// uallocMem allocates user space memory.
func uallocMem(size int) ([]byte, error) {
b, err := syscall.Mmap(
0,
0,
size,
syscall.PROT_READ|syscall.PROT_WRITE,
syscall.MAP_ANONYMOUS|syscall.MAP_LOCKED|syscall.MAP_NORESERVE|syscall.MAP_SHARED)
// syscall.MAP_HUGETLB / MAP_HUGE_2MB
// See /sys/kernel/mm/hugepages but both C.H.I.P. running Jessie and Raspbian
// Jessie do not expose huge pages. :(
if err != nil {
return nil, wrapf("allocating %d bytes failed: %v", size, err)
}
return b, err
}