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