90 lines
2.2 KiB
Go
90 lines
2.2 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 (
|
|
"bytes"
|
|
"math/rand"
|
|
)
|
|
|
|
// TestCopy is used by CPU drivers to verify that the DMA engine works
|
|
// correctly.
|
|
//
|
|
// It is not meant to be used by end users.
|
|
//
|
|
// TestCopy allocates two buffer via `alloc`, once as the source and one as the
|
|
// destination. It fills the source with random data and the destination with
|
|
// 0x11.
|
|
//
|
|
// `copyMem` is expected to copy the memory from pSrc to pDst, with an offset
|
|
// of `hole` and size `size-2*hole`.
|
|
//
|
|
// The function `copyMem` being tested is only given the buffer physical
|
|
// addresses and must copy the data without other help. It is expected to
|
|
//
|
|
// This confirm misaligned DMA copying works.
|
|
// leverage the host's DMA engine.
|
|
func TestCopy(size, holeSize int, alloc func(size int) (Mem, error), copyMem func(pDst, pSrc uint64) error) error {
|
|
pSrc, err2 := alloc(size)
|
|
if err2 != nil {
|
|
return err2
|
|
}
|
|
defer pSrc.Close()
|
|
pDst, err2 := alloc(size)
|
|
if err2 != nil {
|
|
return err2
|
|
}
|
|
defer pDst.Close()
|
|
dst := pDst.Bytes()
|
|
for i := range dst {
|
|
dst[i] = 0x11
|
|
}
|
|
src := make([]byte, size)
|
|
for i := range src {
|
|
src[i] = byte(rand.Int31())
|
|
}
|
|
copy(pSrc.Bytes(), src[:])
|
|
|
|
// Run the driver supplied memory copying code.
|
|
if err := copyMem(pDst.PhysAddr(), pSrc.PhysAddr()); err != nil {
|
|
return err
|
|
}
|
|
|
|
// Verifications.
|
|
for i := 0; i < holeSize; i++ {
|
|
if dst[i] != 0x11 {
|
|
return wrapf("DMA corrupted the buffer header: %x", dst[:holeSize])
|
|
}
|
|
if dst[size-1-i] != 0x11 {
|
|
return wrapf("DMA corrupted the buffer footer: %x", dst[size-1-holeSize:])
|
|
}
|
|
}
|
|
|
|
// Headers and footers were not corupted in the destination. Verify the inner
|
|
// view that should match.
|
|
x := src[:size-2*holeSize]
|
|
y := dst[holeSize : size-holeSize]
|
|
if !bytes.Equal(x, y) {
|
|
offset := 0
|
|
for len(x) != 0 && x[0] == y[0] {
|
|
x = x[1:]
|
|
y = y[1:]
|
|
offset++
|
|
}
|
|
for len(x) != 0 && x[len(x)-1] == y[len(y)-1] {
|
|
x = x[:len(x)-1]
|
|
y = y[:len(y)-1]
|
|
}
|
|
if len(x) > 32 {
|
|
x = x[:32]
|
|
}
|
|
if len(y) > 32 {
|
|
y = y[:32]
|
|
}
|
|
return wrapf("DMA corrupted the buffer at offset %d:\n%x\n%x", offset, x, y)
|
|
}
|
|
return nil
|
|
}
|