/** @file
Cache implementation for EFI FAT File system driver.
Copyright (c) 2005 - 2013, Intel Corporation. All rights reserved.<BR>
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 "Fat.h"
/**
This function is used by the Data Cache.
When this function is called by write command, all entries in this range
are older than the contents in disk, so they are invalid; just mark them invalid.
When this function is called by read command, if any entry in this range
is dirty, it means that the relative info directly readed from media is older than
than the info in the cache; So need to update the relative info in the Buffer.
@param Volume - FAT file system volume.
@param IoMode - This function is called by read command or write command
@param StartPageNo - First PageNo to be checked in the cache.
@param EndPageNo - Last PageNo to be checked in the cache.
@param Buffer - The user buffer need to update. Only when doing the read command
and there is dirty cache in the cache range, this parameter will be used.
**/
STATIC
VOID
FatFlushDataCacheRange (
IN FAT_VOLUME *Volume,
IN IO_MODE IoMode,
IN UINTN StartPageNo,
IN UINTN EndPageNo,
OUT UINT8 *Buffer
)
{
UINTN PageNo;
UINTN GroupNo;
UINTN GroupMask;
UINTN PageSize;
UINT8 PageAlignment;
DISK_CACHE *DiskCache;
CACHE_TAG *CacheTag;
UINT8 *BaseAddress;
DiskCache = &Volume->DiskCache[CacheData];
BaseAddress = DiskCache->CacheBase;
GroupMask = DiskCache->GroupMask;
PageAlignment = DiskCache->PageAlignment;
PageSize = (UINTN)1 << PageAlignment;
for (PageNo = StartPageNo; PageNo < EndPageNo; PageNo++) {
GroupNo = PageNo & GroupMask;
CacheTag = &DiskCache->CacheTag[GroupNo];
if (CacheTag->RealSize > 0 && CacheTag->PageNo == PageNo) {
//
// When reading data form disk directly, if some dirty data
// in cache is in this rang, this data in the Buffer need to
// be updated with the cache's dirty data.
//
if (IoMode == ReadDisk) {
if (CacheTag->Dirty) {
CopyMem (
Buffer + ((PageNo - StartPageNo) << PageAlignment),
BaseAddress + (GroupNo << PageAlignment),
PageSize
);
}
} else {
//
// Make all valid entries in this range invalid.
//
CacheTag->RealSize = 0;
}
}
}
}
/**
Exchange the cache page with the image on the disk
@param Volume - FAT file system volume.
@param DataType - Indicate the cache type.
@param IoMode - Indicate whether to load this page from disk or store this page to disk.
@param CacheTag - The Cache Tag for the current cache page.
@param Task point to task instance.
@retval EFI_SUCCESS - Cache page exchanged successfully.
@return Others - An error occurred when exchanging cache page.
**/
STATIC
EFI_STATUS
FatExchangeCachePage (
IN FAT_VOLUME *Volume,
IN CACHE_DATA_TYPE DataType,
IN IO_MODE IoMode,
IN CACHE_TAG *CacheTag,
IN FAT_TASK *Task
)
{
EFI_STATUS Status;
UINTN GroupNo;
UINTN PageNo;
UINTN WriteCount;
UINTN RealSize;
UINT64 EntryPos;
UINT64 MaxSize;
DISK_CACHE *DiskCache;
VOID *PageAddress;
UINT8 PageAlignment;
DiskCache = &Volume->DiskCache[DataType];
PageNo = CacheTag->PageNo;
GroupNo = PageNo & DiskCache->GroupMask;
PageAlignment = DiskCache->PageAlignment;
PageAddress = DiskCache->CacheBase + (GroupNo << PageAlignment);
EntryPos = DiskCache->BaseAddress + LShiftU64 (PageNo, PageAlignment);
RealSize = CacheTag->RealSize;
if (IoMode == ReadDisk) {
RealSize = (UINTN)1 << PageAlignment;
MaxSize = DiskCache->LimitAddress - EntryPos;
if (MaxSize < RealSize) {
DEBUG ((EFI_D_INFO, "FatDiskIo: Cache Page OutBound occurred! \n"));
RealSize = (UINTN) MaxSize;
}
}
WriteCount = 1;
if (DataType == CacheFat && IoMode == WriteDisk) {
WriteCount = Volume->NumFats;
}
do {
//
// Only fat table writing will execute more than once
//
Status = FatDiskIo (Volume, IoMode, EntryPos, RealSize, PageAddress, Task);
if (EFI_ERROR (Status)) {
return Status;
}
EntryPos += Volume->FatSize;
} while (--WriteCount > 0);
CacheTag->Dirty = FALSE;
CacheTag->RealSize = RealSize;
return EFI_SUCCESS;
}
/**
Get one cache page by specified PageNo.
@param Volume - FAT file system volume.
@param CacheDataType - The cache type: CACHE_FAT or CACHE_DATA.
@param PageNo - PageNo to match with the cache.
@param CacheTag - The Cache Tag for the current cache page.
@retval EFI_SUCCESS - Get the cache page successfully.
@return other - An error occurred when accessing data.
**/
STATIC
EFI_STATUS
FatGetCachePage (
IN FAT_VOLUME *Volume,
IN CACHE_DATA_TYPE CacheDataType,
IN UINTN PageNo,
IN CACHE_TAG *CacheTag
)
{
EFI_STATUS Status;
UINTN OldPageNo;
OldPageNo = CacheTag->PageNo;
if (CacheTag->RealSize > 0 && OldPageNo == PageNo) {
//
// Cache Hit occurred
//
return EFI_SUCCESS;
}
//
// Write dirty cache page back to disk
//
if (CacheTag->RealSize > 0 && CacheTag->Dirty) {
Status = FatExchangeCachePage (Volume, CacheDataType, WriteDisk, CacheTag, NULL);
if (EFI_ERROR (Status)) {
return Status;
}
}
//
// Load new data from disk;
//
CacheTag->PageNo = PageNo;
Status = FatExchangeCachePage (Volume, CacheDataType, ReadDisk, CacheTag, NULL);
return Status;
}
/**
Read Length bytes from the position of Offset into Buffer, or
write Length bytes from Buffer into the position of Offset.
@param Volume - FAT file system volume.
@param CacheDataType - The type of cache: CACHE_DATA or CACHE_FAT.
@param IoMode - Indicate the type of disk access.
@param PageNo - The number of unaligned cache page.
@param Offset - The starting byte of cache page.
@param Length - The number of bytes that is read or written
@param Buffer - Buffer containing cache data.
@retval EFI_SUCCESS - The data was accessed correctly.
@return Others - An error occurred when accessing unaligned cache page.
**/
STATIC
EFI_STATUS
FatAccessUnalignedCachePage (
IN FAT_VOLUME *Volume,
IN CACHE_DATA_TYPE CacheDataType,
IN IO_MODE IoMode,
IN UINTN PageNo,
IN UINTN Offset,
IN UINTN Length,
IN OUT VOID *Buffer
)
{
EFI_STATUS Status;
VOID *Source;
VOID *Destination;
DISK_CACHE *DiskCache;
CACHE_TAG *CacheTag;
UINTN GroupNo;
DiskCache = &Volume->DiskCache[CacheDataType];
GroupNo = PageNo & DiskCache->GroupMask;
CacheTag = &DiskCache->CacheTag[GroupNo];
Status = FatGetCachePage (Volume, CacheDataType, PageNo, CacheTag);
if (!EFI_ERROR (Status)) {
Source = DiskCache->CacheBase + (GroupNo << DiskCache->PageAlignment) + Offset;
Destination = Buffer;
if (IoMode != ReadDisk) {
CacheTag->Dirty = TRUE;
DiskCache->Dirty = TRUE;
Destination = Source;
Source = Buffer;
}
CopyMem (Destination, Source, Length);
}
return Status;
}
/**
Read BufferSize bytes from the position of Offset into Buffer,
or write BufferSize bytes from Buffer into the position of Offset.
Base on the parameter of CACHE_DATA_TYPE, the data access will be divided into
the access of FAT cache (CACHE_FAT) and the access of Data cache (CACHE_DATA):
1. Access of FAT cache (CACHE_FAT): Access the data in the FAT cache, if there is cache
page hit, just return the cache page; else update the related cache page and return
the right cache page.
2. Access of Data cache (CACHE_DATA):
The access data will be divided into UnderRun data, Aligned data and OverRun data;
The UnderRun data and OverRun data will be accessed by the Data cache,
but the Aligned data will be accessed with disk directly.
@param Volume - FAT file system volume.
@param CacheDataType - The type of cache: CACHE_DATA or CACHE_FAT.
@param IoMode - Indicate the type of disk access.
@param Offset - The starting byte offset to read from.
@param BufferSize - Size of Buffer.
@param Buffer - Buffer containing cache data.
@param Task point to task instance.
@retval EFI_SUCCESS - The data was accessed correctly.
@retval EFI_MEDIA_CHANGED - The MediaId does not match the current device.
@return Others - An error occurred when accessing cache.
**/
EFI_STATUS
FatAccessCache (
IN FAT_VOLUME *Volume,
IN CACHE_DATA_TYPE CacheDataType,
IN IO_MODE IoMode,
IN UINT64 Offset,
IN UINTN BufferSize,
IN OUT UINT8 *Buffer,
IN FAT_TASK *Task
)
{
EFI_STATUS Status;
UINTN PageSize;
UINTN UnderRun;
UINTN OverRun;
UINTN AlignedSize;
UINTN Length;
UINTN PageNo;
UINTN AlignedPageCount;
UINTN OverRunPageNo;
DISK_CACHE *DiskCache;
UINT64 EntryPos;
UINT8 PageAlignment;
ASSERT (Volume->CacheBuffer != NULL);
Status = EFI_SUCCESS;
DiskCache = &Volume->DiskCache[CacheDataType];
EntryPos = Offset - DiskCache->BaseAddress;
PageAlignment = DiskCache->PageAlignment;
PageSize = (UINTN)1 << PageAlignment;
PageNo = (UINTN) RShiftU64 (EntryPos, PageAlignment);
UnderRun = ((UINTN) EntryPos) & (PageSize - 1);
if (UnderRun > 0) {
Length = PageSize - UnderRun;
if (Length > BufferSize) {
Length = BufferSize;
}
Status = FatAccessUnalignedCachePage (Volume, CacheDataType, IoMode, PageNo, UnderRun, Length, Buffer);
if (EFI_ERROR (Status)) {
return Status;
}
Buffer += Length;
BufferSize -= Length;
PageNo++;
}
AlignedPageCount = BufferSize >> PageAlignment;
OverRunPageNo = PageNo + AlignedPageCount;
//
// The access of the Aligned data
//
if (AlignedPageCount > 0) {
//
// Accessing fat table cannot have alignment data
//
ASSERT (CacheDataType == CacheData);
EntryPos = Volume->RootPos + LShiftU64 (PageNo, PageAlignment);
AlignedSize = AlignedPageCount << PageAlignment;
Status = FatDiskIo (Volume, IoMode, EntryPos, AlignedSize, Buffer, Task);
if (EFI_ERROR (Status)) {
return Status;
}
//
// If these access data over laps the relative cache range, these cache pages need
// to be updated.
//
FatFlushDataCacheRange (Volume, IoMode, PageNo, OverRunPageNo, Buffer);
Buffer += AlignedSize;
BufferSize -= AlignedSize;
}
//
// The access of the OverRun data
//
OverRun = BufferSize;
if (OverRun > 0) {
//
// Last read is not a complete page
//
Status = FatAccessUnalignedCachePage (Volume, CacheDataType, IoMode, OverRunPageNo, 0, OverRun, Buffer);
}
return Status;
}
/**
Flush all the dirty cache back, include the FAT cache and the Data cache.
@param Volume - FAT file system volume.
@param Task point to task instance.
@retval EFI_SUCCESS - Flush all the dirty cache back successfully
@return other - An error occurred when writing the data into the disk
**/
EFI_STATUS
FatVolumeFlushCache (
IN FAT_VOLUME *Volume,
IN FAT_TASK *Task
)
{
EFI_STATUS Status;
CACHE_DATA_TYPE CacheDataType;
UINTN GroupIndex;
UINTN GroupMask;
DISK_CACHE *DiskCache;
CACHE_TAG *CacheTag;
for (CacheDataType = (CACHE_DATA_TYPE) 0; CacheDataType < CacheMaxType; CacheDataType++) {
DiskCache = &Volume->DiskCache[CacheDataType];
if (DiskCache->Dirty) {
//
// Data cache or fat cache is dirty, write the dirty data back
//
GroupMask = DiskCache->GroupMask;
for (GroupIndex = 0; GroupIndex <= GroupMask; GroupIndex++) {
CacheTag = &DiskCache->CacheTag[GroupIndex];
if (CacheTag->RealSize > 0 && CacheTag->Dirty) {
//
// Write back all Dirty Data Cache Page to disk
//
Status = FatExchangeCachePage (Volume, CacheDataType, WriteDisk, CacheTag, Task);
if (EFI_ERROR (Status)) {
return Status;
}
}
}
DiskCache->Dirty = FALSE;
}
}
//
// Flush the block device.
//
Status = Volume->BlockIo->FlushBlocks (Volume->BlockIo);
return Status;
}
/**
Initialize the disk cache according to Volume's FatType.
@param Volume - FAT file system volume.
@retval EFI_SUCCESS - The disk cache is successfully initialized.
@retval EFI_OUT_OF_RESOURCES - Not enough memory to allocate disk cache.
**/
EFI_STATUS
FatInitializeDiskCache (
IN FAT_VOLUME *Volume
)
{
DISK_CACHE *DiskCache;
UINTN FatCacheGroupCount;
UINTN DataCacheSize;
UINTN FatCacheSize;
UINT8 *CacheBuffer;
DiskCache = Volume->DiskCache;
//
// Configure the parameters of disk cache
//
if (Volume->FatType == Fat12) {
FatCacheGroupCount = FAT_FATCACHE_GROUP_MIN_COUNT;
DiskCache[CacheFat].PageAlignment = FAT_FATCACHE_PAGE_MIN_ALIGNMENT;
DiskCache[CacheData].PageAlignment = FAT_DATACACHE_PAGE_MIN_ALIGNMENT;
} else {
FatCacheGroupCount = FAT_FATCACHE_GROUP_MAX_COUNT;
DiskCache[CacheFat].PageAlignment = FAT_FATCACHE_PAGE_MAX_ALIGNMENT;
DiskCache[CacheData].PageAlignment = FAT_DATACACHE_PAGE_MAX_ALIGNMENT;
}
DiskCache[CacheData].GroupMask = FAT_DATACACHE_GROUP_COUNT - 1;
DiskCache[CacheData].BaseAddress = Volume->RootPos;
DiskCache[CacheData].LimitAddress = Volume->VolumeSize;
DiskCache[CacheFat].GroupMask = FatCacheGroupCount - 1;
DiskCache[CacheFat].BaseAddress = Volume->FatPos;
DiskCache[CacheFat].LimitAddress = Volume->FatPos + Volume->FatSize;
FatCacheSize = FatCacheGroupCount << DiskCache[CacheFat].PageAlignment;
DataCacheSize = FAT_DATACACHE_GROUP_COUNT << DiskCache[CacheData].PageAlignment;
//
// Allocate the Fat Cache buffer
//
CacheBuffer = AllocateZeroPool (FatCacheSize + DataCacheSize);
if (CacheBuffer == NULL) {
return EFI_OUT_OF_RESOURCES;
}
Volume->CacheBuffer = CacheBuffer;
DiskCache[CacheFat].CacheBase = CacheBuffer;
DiskCache[CacheData].CacheBase = CacheBuffer + FatCacheSize;
return EFI_SUCCESS;
}