/** @file

   Internal functions to operate Working Block Space.

Copyright (c) 2006 - 2008, Intel Corporation                                                         
All rights reserved. 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 <FtwLite.h>

BOOLEAN
IsValidWorkSpace (
  IN EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER *WorkingHeader
  )
/*++

Routine Description:
    Check to see if it is a valid work space.

Arguments:
    WorkingHeader - Pointer of working block header 

Returns:
    EFI_SUCCESS   - The function completed successfully
    EFI_ABORTED   - The function could not complete successfully.

--*/
{
  EFI_STATUS                              Status;
  EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER WorkingBlockHeader;

  ASSERT (WorkingHeader != NULL);
  if (WorkingHeader->WorkingBlockValid != FTW_VALID_STATE) {
    return FALSE;
  }
  //
  // Check signature with gEfiSystemNvDataFvGuid
  //
  if (!CompareGuid (&gEfiSystemNvDataFvGuid, &WorkingHeader->Signature)) {
    return FALSE;
  }
  //
  // Check the CRC of header
  //
  CopyMem (
    &WorkingBlockHeader,
    WorkingHeader,
    sizeof (EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER)
    );

  //
  // Filter out the Crc and State fields
  //
  SetMem (
    &WorkingBlockHeader.Crc,
    sizeof (UINT32),
    FTW_ERASED_BYTE
    );
  WorkingBlockHeader.WorkingBlockValid    = FTW_ERASE_POLARITY;
  WorkingBlockHeader.WorkingBlockInvalid  = FTW_ERASE_POLARITY;

  //
  // Calculate the Crc of woking block header
  //
  Status = gBS->CalculateCrc32 (
                  (UINT8 *) &WorkingBlockHeader,
                  sizeof (EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER),
                  &WorkingBlockHeader.Crc
                  );
  ASSERT_EFI_ERROR (Status);

  if (WorkingBlockHeader.Crc != WorkingHeader->Crc) {
    DEBUG ((EFI_D_FTW_LITE, "FtwLite: Work block header CRC check error\n"));
    return FALSE;
  }

  return TRUE;
}

EFI_STATUS
InitWorkSpaceHeader (
  IN EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER *WorkingHeader
  )
/*++

Routine Description:
    Initialize a work space when there is no work space.

Arguments:
    WorkingHeader - Pointer of working block header 

Returns:
    EFI_SUCCESS   - The function completed successfully
    EFI_ABORTED   - The function could not complete successfully.

--*/
{
  EFI_STATUS  Status;

  ASSERT (WorkingHeader != NULL);

  //
  // Here using gEfiSystemNvDataFvGuid as the signature.
  //
  CopyMem (
    &WorkingHeader->Signature,
    &gEfiSystemNvDataFvGuid,
    sizeof (EFI_GUID)
    );
  WorkingHeader->WriteQueueSize = FTW_WORKING_QUEUE_SIZE;

  //
  // Crc is calculated with all the fields except Crc and STATE
  //
  WorkingHeader->WorkingBlockValid    = FTW_ERASE_POLARITY;
  WorkingHeader->WorkingBlockInvalid  = FTW_ERASE_POLARITY;
  SetMem (&WorkingHeader->Crc, sizeof (UINT32), FTW_ERASED_BYTE);

  //
  // Calculate the CRC value
  //
  Status = gBS->CalculateCrc32 (
                  (UINT8 *) WorkingHeader,
                  sizeof (EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER),
                  &WorkingHeader->Crc
                  );
  ASSERT_EFI_ERROR (Status);

  //
  // Restore the WorkingBlockValid flag to VALID state
  //
  WorkingHeader->WorkingBlockValid    = FTW_VALID_STATE;
  WorkingHeader->WorkingBlockInvalid  = FTW_INVALID_STATE;

  return EFI_SUCCESS;
}

EFI_STATUS
FtwUpdateFvState (
  IN EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *FvBlock,
  IN EFI_LBA                             Lba,
  IN UINTN                               Offset,
  IN UINT8                               NewBit
  )
/*++

Routine Description:
    Update a bit of state on a block device. The location of the bit is 
    calculated by the (Lba, Offset, bit). Here bit is determined by the 
    the name of a certain bit.

Arguments:
    FvBlock    - FVB Protocol interface to access SrcBlock and DestBlock
    Lba        - Lba of a block
    Offset     - Offset on the Lba
    NewBit     - New value that will override the old value if it can be change

Returns:
    EFI_SUCCESS   - A state bit has been updated successfully
    Others        - Access block device error.

Notes:
    Assume all bits of State are inside the same BYTE. 

    EFI_ABORTED   - Read block fail
--*/
{
  EFI_STATUS  Status;
  UINT8       State;
  UINTN       Length;

  //
  // Read state from device, assume State is only one byte.
  //
  Length  = sizeof (UINT8);
  Status  = FvBlock->Read (FvBlock, Lba, Offset, &Length, &State);
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }

  State ^= FTW_POLARITY_REVERT;
  State = (UINT8) (State | NewBit);
  State ^= FTW_POLARITY_REVERT;

  //
  // Write state back to device
  //
  Length  = sizeof (UINT8);
  Status  = FvBlock->Write (FvBlock, Lba, Offset, &Length, &State);

  return Status;
}

EFI_STATUS
FtwGetLastRecord (
  IN  EFI_FTW_LITE_DEVICE  *FtwLiteDevice,
  OUT EFI_FTW_LITE_RECORD  **FtwLastRecord
  )
/*++

Routine Description:
    Get the last Write record pointer. 
    The last record is the record whose 'complete' state hasn't been set.
    After all, this header may be a EMPTY header entry for next Allocate. 

Arguments:
    FtwLiteDevice   - Private data of this driver
    FtwLastRecord   - Pointer to retrieve the last write record

Returns:
    EFI_SUCCESS     - Get the last write record successfully
    EFI_ABORTED     - The FTW work space is damaged

--*/
{
  EFI_FTW_LITE_RECORD *Record;

  Record = (EFI_FTW_LITE_RECORD *) (FtwLiteDevice->FtwWorkSpaceHeader + 1);
  while (Record->WriteCompleted == FTW_VALID_STATE) {
    //
    // If Offset exceed the FTW work space boudary, return error.
    //
    if ((UINTN) ((UINT8 *) Record - FtwLiteDevice->FtwWorkSpace) > FtwLiteDevice->FtwWorkSpaceSize) {
      return EFI_ABORTED;
    }

    Record++;
  }
  //
  // Last write record is found
  //
  *FtwLastRecord = Record;
  return EFI_SUCCESS;
}

EFI_STATUS
WorkSpaceRefresh (
  IN EFI_FTW_LITE_DEVICE  *FtwLiteDevice
  )
/*++

Routine Description:
    Read from working block to refresh the work space in memory.

Arguments:
    FtwLiteDevice     - Point to private data of FTW driver

Returns:
    EFI_SUCCESS   - The function completed successfully
    EFI_ABORTED   - The function could not complete successfully.

--*/
{
  EFI_STATUS          Status;
  UINTN               Length;
  UINTN               Offset;
  EFI_FTW_LITE_RECORD *Record;

  //
  // Initialize WorkSpace as FTW_ERASED_BYTE
  //
  SetMem (
    FtwLiteDevice->FtwWorkSpace,
    FtwLiteDevice->FtwWorkSpaceSize,
    FTW_ERASED_BYTE
    );

  //
  // Read from working block
  //
  Length = FtwLiteDevice->FtwWorkSpaceSize;
  Status = FtwLiteDevice->FtwFvBlock->Read (
                                        FtwLiteDevice->FtwFvBlock,
                                        FtwLiteDevice->FtwWorkSpaceLba,
                                        FtwLiteDevice->FtwWorkSpaceBase,
                                        &Length,
                                        FtwLiteDevice->FtwWorkSpace
                                        );
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }
  //
  // Refresh the FtwLastRecord
  //
  Status  = FtwGetLastRecord (FtwLiteDevice, &FtwLiteDevice->FtwLastRecord);

  Record  = FtwLiteDevice->FtwLastRecord;
  Offset  = (UINTN) (UINT8 *) Record - (UINTN) FtwLiteDevice->FtwWorkSpace;

  //
  // IF work space has error or Record is out of the workspace limit, THEN
  //   call reclaim.
  //
  if (EFI_ERROR (Status) || (Offset + WRITE_TOTAL_SIZE >= FtwLiteDevice->FtwWorkSpaceSize)) {
    //
    // reclaim work space in working block.
    //
    Status = FtwReclaimWorkSpace (FtwLiteDevice);
    if (EFI_ERROR (Status)) {
      DEBUG ((EFI_D_FTW_LITE, "FtwLite: Reclaim workspace - %r\n", Status));
      return EFI_ABORTED;
    }
  }

  return EFI_SUCCESS;
}

EFI_STATUS
CleanupWorkSpace (
  IN EFI_FTW_LITE_DEVICE  *FtwLiteDevice,
  IN OUT UINT8            *FtwSpaceBuffer,
  IN UINTN                BufferSize
  )
/*++

Routine Description:
    Reclaim the work space. Get rid of all the completed write records
    and write records in the Fault Tolerant work space.

Arguments:
    FtwLiteDevice   - Point to private data of FTW driver
    FtwSpaceBuffer  - Buffer to contain the reclaimed clean data
    BufferSize      - Size of the FtwSpaceBuffer

Returns:
    EFI_SUCCESS           - The function completed successfully
    EFI_BUFFER_TOO_SMALL  - The FtwSpaceBuffer is too small
    EFI_ABORTED           - The function could not complete successfully.

--*/
{
  UINTN               Length;
  EFI_FTW_LITE_RECORD *Record;

  //
  // To check if the buffer is large enough
  //
  Length = FtwLiteDevice->FtwWorkSpaceSize;
  if (BufferSize < Length) {
    return EFI_BUFFER_TOO_SMALL;
  }
  //
  // Clear the content of buffer that will save the new work space data
  //
  SetMem (FtwSpaceBuffer, Length, FTW_ERASED_BYTE);

  //
  // Copy EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER to buffer
  //
  CopyMem (
    FtwSpaceBuffer,
    FtwLiteDevice->FtwWorkSpaceHeader,
    sizeof (EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER)
    );

  //
  // Get the last record
  //
  Record = FtwLiteDevice->FtwLastRecord;
  if ((Record != NULL) && (Record->WriteAllocated == FTW_VALID_STATE) && (Record->WriteCompleted != FTW_VALID_STATE)) {
    CopyMem (
      (UINT8 *) FtwSpaceBuffer + sizeof (EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER),
      Record,
      WRITE_TOTAL_SIZE
      );
  }

  return EFI_SUCCESS;
}

EFI_STATUS
FtwReclaimWorkSpace (
  IN EFI_FTW_LITE_DEVICE  *FtwLiteDevice
  )
/*++

Routine Description:
    Reclaim the work space on the working block.

Arguments:
    FtwLiteDevice     - Point to private data of FTW driver

Returns:
    EFI_SUCCESS           - The function completed successfully
    EFI_OUT_OF_RESOURCES  - Allocate memory error
    EFI_ABORTED           - The function could not complete successfully

--*/
{
  EFI_STATUS                              Status;
  UINT8                                   *TempBuffer;
  UINTN                                   TempBufferSize;
  UINT8                                   *Ptr;
  UINTN                                   Length;
  UINTN                                   Index;
  UINTN                                   SpareBufferSize;
  UINT8                                   *SpareBuffer;
  EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER *WorkingBlockHeader;

  DEBUG ((EFI_D_FTW_LITE, "FtwLite: start to reclaim work space\n"));

  //
  // Read all original data from working block to a memory buffer
  //
  TempBufferSize = FtwLiteDevice->SpareAreaLength;
  TempBuffer     = AllocateZeroPool (TempBufferSize);
  if (TempBuffer != NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  Ptr = TempBuffer;
  for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {
    Length = FtwLiteDevice->SizeOfSpareBlock;
    Status = FtwLiteDevice->FtwFvBlock->Read (
                                          FtwLiteDevice->FtwFvBlock,
                                          FtwLiteDevice->FtwWorkBlockLba + Index,
                                          0,
                                          &Length,
                                          Ptr
                                          );
    if (EFI_ERROR (Status)) {
      FreePool (TempBuffer);
      return EFI_ABORTED;
    }

    Ptr += Length;
  }
  //
  // Clean up the workspace, remove all the completed records.
  //
  Ptr = TempBuffer +
    ((UINTN) (FtwLiteDevice->FtwWorkSpaceLba - FtwLiteDevice->FtwWorkBlockLba)) *
    FtwLiteDevice->SizeOfSpareBlock + FtwLiteDevice->FtwWorkSpaceBase;

  Status = CleanupWorkSpace (
            FtwLiteDevice,
            Ptr,
            FtwLiteDevice->FtwWorkSpaceSize
            );

  CopyMem (
    FtwLiteDevice->FtwWorkSpace,
    Ptr,
    FtwLiteDevice->FtwWorkSpaceSize
    );

  Status = FtwGetLastRecord (FtwLiteDevice, &FtwLiteDevice->FtwLastRecord);

  //
  // Set the WorkingBlockValid and WorkingBlockInvalid as INVALID
  //
  WorkingBlockHeader                      = (EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER *) Ptr;
  WorkingBlockHeader->WorkingBlockValid   = FTW_INVALID_STATE;
  WorkingBlockHeader->WorkingBlockInvalid = FTW_INVALID_STATE;

  //
  // Try to keep the content of spare block
  // Save spare block into a spare backup memory buffer (Sparebuffer)
  //
  SpareBufferSize = FtwLiteDevice->SpareAreaLength;
  SpareBuffer     = AllocatePool (SpareBufferSize);
  if (SpareBuffer == NULL) {
    FreePool (TempBuffer);
    return EFI_OUT_OF_RESOURCES;
  }

  Ptr = SpareBuffer;
  for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {
    Length = FtwLiteDevice->SizeOfSpareBlock;
    Status = FtwLiteDevice->FtwBackupFvb->Read (
                                            FtwLiteDevice->FtwBackupFvb,
                                            FtwLiteDevice->FtwSpareLba + Index,
                                            0,
                                            &Length,
                                            Ptr
                                            );
    if (EFI_ERROR (Status)) {
      FreePool (TempBuffer);
      FreePool (SpareBuffer);
      return EFI_ABORTED;
    }

    Ptr += Length;
  }
  //
  // Write the memory buffer to spare block
  //
  Status  = FtwEraseSpareBlock (FtwLiteDevice);
  Ptr     = TempBuffer;
  for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {
    Length = FtwLiteDevice->SizeOfSpareBlock;
    Status = FtwLiteDevice->FtwBackupFvb->Write (
                                            FtwLiteDevice->FtwBackupFvb,
                                            FtwLiteDevice->FtwSpareLba + Index,
                                            0,
                                            &Length,
                                            Ptr
                                            );
    if (EFI_ERROR (Status)) {
      FreePool (TempBuffer);
      FreePool (SpareBuffer);
      return EFI_ABORTED;
    }

    Ptr += Length;
  }
  //
  // Free TempBuffer
  //
  FreePool (TempBuffer);

  //
  // Write the spare block to working block
  //
  Status = FlushSpareBlockToWorkingBlock (FtwLiteDevice);
  if (EFI_ERROR (Status)) {
    FreePool (SpareBuffer);
    return Status;
  }
  //
  // Restore spare backup buffer into spare block , if no failure happened during FtwWrite.
  //
  Status  = FtwEraseSpareBlock (FtwLiteDevice);
  Ptr     = SpareBuffer;
  for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {
    Length = FtwLiteDevice->SizeOfSpareBlock;
    Status = FtwLiteDevice->FtwBackupFvb->Write (
                                            FtwLiteDevice->FtwBackupFvb,
                                            FtwLiteDevice->FtwSpareLba + Index,
                                            0,
                                            &Length,
                                            Ptr
                                            );
    if (EFI_ERROR (Status)) {
      FreePool (SpareBuffer);
      return EFI_ABORTED;
    }

    Ptr += Length;
  }

  FreePool (SpareBuffer);

  DEBUG ((EFI_D_FTW_LITE, "FtwLite: reclaim work space success\n"));

  return EFI_SUCCESS;
}