/** @file
BlockIo implementation for Xen PV Block driver.
This file is implementing the interface between the actual driver in
BlockFront.c to the BlockIo protocol.
Copyright (C) 2014, Citrix Ltd.
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include "XenPvBlkDxe.h"
#include "BlockFront.h"
///
/// Block I/O Media structure
///
GLOBAL_REMOVE_IF_UNREFERENCED
EFI_BLOCK_IO_MEDIA gXenPvBlkDxeBlockIoMedia = {
0, // MediaId
FALSE, // RemovableMedia
FALSE, // MediaPresent
FALSE, // LogicalPartition
TRUE, // ReadOnly
FALSE, // WriteCaching
512, // BlockSize
512, // IoAlign, BlockFront does not support less than 512 bits-aligned.
0, // LastBlock
0, // LowestAlignedLba
0, // LogicalBlocksPerPhysicalBlock
0 // OptimalTransferLengthGranularity
};
///
/// Block I/O Protocol instance
///
GLOBAL_REMOVE_IF_UNREFERENCED
EFI_BLOCK_IO_PROTOCOL gXenPvBlkDxeBlockIo = {
EFI_BLOCK_IO_PROTOCOL_REVISION3, // Revision
&gXenPvBlkDxeBlockIoMedia, // Media
XenPvBlkDxeBlockIoReset, // Reset
XenPvBlkDxeBlockIoReadBlocks, // ReadBlocks
XenPvBlkDxeBlockIoWriteBlocks, // WriteBlocks
XenPvBlkDxeBlockIoFlushBlocks // FlushBlocks
};
/**
Read/Write BufferSize bytes from Lba into Buffer.
This function is commun to XenPvBlkDxeBlockIoReadBlocks and
XenPvBlkDxeBlockIoWriteBlocks.
@param This Indicates a pointer to the calling context.
@param MediaId Id of the media, changes every time the media is replaced.
@param Lba The starting Logical Block Address to read from/write to.
@param BufferSize Size of Buffer, must be a multiple of device block size.
@param Buffer A pointer to the destination/source buffer for the data.
@param IsWrite Indicate if the operation is write or read.
@return See description of XenPvBlkDxeBlockIoReadBlocks and
XenPvBlkDxeBlockIoWriteBlocks.
**/
STATIC
EFI_STATUS
XenPvBlkDxeBlockIoReadWriteBlocks (
IN EFI_BLOCK_IO_PROTOCOL *This,
IN UINT32 MediaId,
IN EFI_LBA Lba,
IN UINTN BufferSize,
IN OUT VOID *Buffer,
IN BOOLEAN IsWrite
)
{
XEN_BLOCK_FRONT_IO IoData;
EFI_BLOCK_IO_MEDIA *Media = This->Media;
UINTN Sector;
EFI_STATUS Status;
if (Buffer == NULL) {
return EFI_INVALID_PARAMETER;
}
if (BufferSize == 0) {
return EFI_SUCCESS;
}
if (BufferSize % Media->BlockSize != 0) {
DEBUG ((EFI_D_ERROR, "XenPvBlkDxe: Bad buffer size: 0x%Lx\n",
(UINT64)BufferSize));
return EFI_BAD_BUFFER_SIZE;
}
if (Lba > Media->LastBlock ||
(BufferSize / Media->BlockSize) - 1 > Media->LastBlock - Lba) {
DEBUG ((EFI_D_ERROR,
"XenPvBlkDxe: %a with invalid LBA: 0x%Lx, size: 0x%Lx\n",
IsWrite ? "Write" : "Read", Lba, (UINT64)BufferSize));
return EFI_INVALID_PARAMETER;
}
if (IsWrite && Media->ReadOnly) {
return EFI_WRITE_PROTECTED;
}
if ((Media->IoAlign > 1) && (UINTN)Buffer & (Media->IoAlign - 1)) {
//
// Grub2 does not appear to respect IoAlign of 512, so reallocate the
// buffer here.
//
VOID *NewBuffer;
//
// Try again with a properly aligned buffer.
//
NewBuffer = AllocateAlignedPages((BufferSize + EFI_PAGE_SIZE) / EFI_PAGE_SIZE,
Media->IoAlign);
if (!IsWrite) {
Status = XenPvBlkDxeBlockIoReadBlocks (This, MediaId,
Lba, BufferSize, NewBuffer);
CopyMem (Buffer, NewBuffer, BufferSize);
} else {
CopyMem (NewBuffer, Buffer, BufferSize);
Status = XenPvBlkDxeBlockIoWriteBlocks (This, MediaId,
Lba, BufferSize, NewBuffer);
}
FreeAlignedPages (NewBuffer, (BufferSize + EFI_PAGE_SIZE) / EFI_PAGE_SIZE);
return Status;
}
IoData.Dev = XEN_BLOCK_FRONT_FROM_BLOCK_IO (This);
Sector = (UINTN)MultU64x32 (Lba, Media->BlockSize / 512);
while (BufferSize > 0) {
if (((UINTN)Buffer & EFI_PAGE_MASK) == 0) {
IoData.Size = MIN (BLKIF_MAX_SEGMENTS_PER_REQUEST * EFI_PAGE_SIZE,
BufferSize);
} else {
IoData.Size = MIN ((BLKIF_MAX_SEGMENTS_PER_REQUEST - 1) * EFI_PAGE_SIZE,
BufferSize);
}
IoData.Buffer = Buffer;
IoData.Sector = Sector;
BufferSize -= IoData.Size;
Buffer = (VOID*) ((UINTN) Buffer + IoData.Size);
Sector += IoData.Size / 512;
Status = XenPvBlockIo (&IoData, IsWrite);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "XenPvBlkDxe: Error during %a operation.\n",
IsWrite ? "write" : "read"));
return Status;
}
}
return EFI_SUCCESS;
}
/**
Read BufferSize bytes from Lba into Buffer.
@param This Indicates a pointer to the calling context.
@param MediaId Id of the media, changes every time the media is replaced.
@param Lba The starting Logical Block Address to read from
@param BufferSize Size of Buffer, must be a multiple of device block size.
@param Buffer A pointer to the destination buffer for the data. The caller is
responsible for either having implicit or explicit ownership of the buffer.
@retval EFI_SUCCESS The data was read correctly from the device.
@retval EFI_DEVICE_ERROR The device reported an error while performing the read.
@retval EFI_NO_MEDIA There is no media in the device.
@retval EFI_MEDIA_CHANGED The MediaId does not matched the current device.
@retval EFI_BAD_BUFFER_SIZE The Buffer was not a multiple of the block size of the device.
@retval EFI_INVALID_PARAMETER The read request contains LBAs that are not valid,
or the buffer is not on proper alignment.
**/
EFI_STATUS
EFIAPI
XenPvBlkDxeBlockIoReadBlocks (
IN EFI_BLOCK_IO_PROTOCOL *This,
IN UINT32 MediaId,
IN EFI_LBA Lba,
IN UINTN BufferSize,
OUT VOID *Buffer
)
{
return XenPvBlkDxeBlockIoReadWriteBlocks (This,
MediaId, Lba, BufferSize, Buffer, FALSE);
}
/**
Write BufferSize bytes from Lba into Buffer.
@param This Indicates a pointer to the calling context.
@param MediaId The media ID that the write request is for.
@param Lba The starting logical block address to be written. The caller is
responsible for writing to only legitimate locations.
@param BufferSize Size of Buffer, must be a multiple of device block size.
@param Buffer A pointer to the source buffer for the data.
@retval EFI_SUCCESS The data was written correctly to the device.
@retval EFI_WRITE_PROTECTED The device can not be written to.
@retval EFI_DEVICE_ERROR The device reported an error while performing the write.
@retval EFI_NO_MEDIA There is no media in the device.
@retval EFI_MEDIA_CHNAGED The MediaId does not matched the current device.
@retval EFI_BAD_BUFFER_SIZE The Buffer was not a multiple of the block size of the device.
@retval EFI_INVALID_PARAMETER The write request contains LBAs that are not valid,
or the buffer is not on proper alignment.
**/
EFI_STATUS
EFIAPI
XenPvBlkDxeBlockIoWriteBlocks (
IN EFI_BLOCK_IO_PROTOCOL *This,
IN UINT32 MediaId,
IN EFI_LBA Lba,
IN UINTN BufferSize,
IN VOID *Buffer
)
{
return XenPvBlkDxeBlockIoReadWriteBlocks (This,
MediaId, Lba, BufferSize, Buffer, TRUE);
}
/**
Flush the Block Device.
@param This Indicates a pointer to the calling context.
@retval EFI_SUCCESS All outstanding data was written to the device
@retval EFI_DEVICE_ERROR The device reported an error while writting back the data
@retval EFI_NO_MEDIA There is no media in the device.
**/
EFI_STATUS
EFIAPI
XenPvBlkDxeBlockIoFlushBlocks (
IN EFI_BLOCK_IO_PROTOCOL *This
)
{
XenPvBlockSync (XEN_BLOCK_FRONT_FROM_BLOCK_IO (This));
return EFI_SUCCESS;
}
/**
Reset the block device hardware.
@param[in] This Indicates a pointer to the calling context.
@param[in] ExtendedVerification Not used.
@retval EFI_SUCCESS The device was reset.
**/
EFI_STATUS
EFIAPI
XenPvBlkDxeBlockIoReset (
IN EFI_BLOCK_IO_PROTOCOL *This,
IN BOOLEAN ExtendedVerification
)
{
//
// Since the initialization of the devices is done, then the device is
// working correctly.
//
return EFI_SUCCESS;
}