[mirror_edk2.git] / MdeModulePkg / Universal / Disk / DiskIoDxe / DiskIo.c

/** @file\r
  DiskIo driver that lays on every BlockIo protocol in the system.\r
  DiskIo converts a block oriented device to a byte oriented device.\r
\r
  Disk access may have to handle unaligned request about sector boundaries.\r
  There are three cases:\r
    UnderRun - The first byte is not on a sector boundary or the read request is\r
               less than a sector in length.\r
    Aligned  - A read of N contiguous sectors.\r
    OverRun  - The last byte is not on a sector boundary.\r
\r
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "DiskIo.h"\r
\r
//\r
// Driver binding protocol implementation for DiskIo driver.\r
//\r
EFI_DRIVER_BINDING_PROTOCOL  gDiskIoDriverBinding = {\r
  DiskIoDriverBindingSupported,\r
  DiskIoDriverBindingStart,\r
  DiskIoDriverBindingStop,\r
  0xa,\r
  NULL,\r
  NULL\r
};\r
\r
//\r
// Template for DiskIo private data structure.\r
// The pointer to BlockIo protocol interface is assigned dynamically.\r
//\r
DISK_IO_PRIVATE_DATA  gDiskIoPrivateDataTemplate = {\r
  DISK_IO_PRIVATE_DATA_SIGNATURE,\r
  {\r
    EFI_DISK_IO_PROTOCOL_REVISION,\r
    DiskIoReadDisk,\r
    DiskIoWriteDisk\r
  },\r
  {\r
    EFI_DISK_IO2_PROTOCOL_REVISION,\r
    DiskIo2Cancel,\r
    DiskIo2ReadDiskEx,\r
    DiskIo2WriteDiskEx,\r
    DiskIo2FlushDiskEx\r
  }\r
};\r
\r
/**\r
  Test to see if this driver supports ControllerHandle.\r
\r
  @param  This                Protocol instance pointer.\r
  @param  ControllerHandle    Handle of device to test\r
  @param  RemainingDevicePath Optional parameter use to pick a specific child\r
                              device to start.\r
\r
  @retval EFI_SUCCESS         This driver supports this device\r
  @retval EFI_ALREADY_STARTED This driver is already running on this device\r
  @retval other               This driver does not support this device\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
DiskIoDriverBindingSupported (\r
  IN EFI_DRIVER_BINDING_PROTOCOL  *This,\r
  IN EFI_HANDLE                   ControllerHandle,\r
  IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL\r
  )\r
{\r
  EFI_STATUS             Status;\r
  EFI_BLOCK_IO_PROTOCOL  *BlockIo;\r
\r
  //\r
  // Open the IO Abstraction(s) needed to perform the supported test.\r
  //\r
  Status = gBS->OpenProtocol (\r
                  ControllerHandle,\r
                  &gEfiBlockIoProtocolGuid,\r
                  (VOID **)&BlockIo,\r
                  This->DriverBindingHandle,\r
                  ControllerHandle,\r
                  EFI_OPEN_PROTOCOL_BY_DRIVER\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  //\r
  // Close the I/O Abstraction(s) used to perform the supported test.\r
  //\r
  gBS->CloseProtocol (\r
         ControllerHandle,\r
         &gEfiBlockIoProtocolGuid,\r
         This->DriverBindingHandle,\r
         ControllerHandle\r
         );\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Start this driver on ControllerHandle by opening a Block IO protocol and\r
  installing a Disk IO protocol on ControllerHandle.\r
\r
  @param  This                 Protocol instance pointer.\r
  @param  ControllerHandle     Handle of device to bind driver to\r
  @param  RemainingDevicePath  Optional parameter use to pick a specific child\r
                               device to start.\r
\r
  @retval EFI_SUCCESS          This driver is added to ControllerHandle\r
  @retval EFI_ALREADY_STARTED  This driver is already running on ControllerHandle\r
  @retval other                This driver does not support this device\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
DiskIoDriverBindingStart (\r
  IN EFI_DRIVER_BINDING_PROTOCOL  *This,\r
  IN EFI_HANDLE                   ControllerHandle,\r
  IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL\r
  )\r
{\r
  EFI_STATUS            Status;\r
  DISK_IO_PRIVATE_DATA  *Instance;\r
  EFI_TPL               OldTpl;\r
\r
  Instance = NULL;\r
\r
  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);\r
\r
  //\r
  // Connect to the Block IO and Block IO2 interface on ControllerHandle.\r
  //\r
  Status = gBS->OpenProtocol (\r
                  ControllerHandle,\r
                  &gEfiBlockIoProtocolGuid,\r
                  (VOID **)&gDiskIoPrivateDataTemplate.BlockIo,\r
                  This->DriverBindingHandle,\r
                  ControllerHandle,\r
                  EFI_OPEN_PROTOCOL_BY_DRIVER\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    goto ErrorExit1;\r
  }\r
\r
  Status = gBS->OpenProtocol (\r
                  ControllerHandle,\r
                  &gEfiBlockIo2ProtocolGuid,\r
                  (VOID **)&gDiskIoPrivateDataTemplate.BlockIo2,\r
                  This->DriverBindingHandle,\r
                  ControllerHandle,\r
                  EFI_OPEN_PROTOCOL_BY_DRIVER\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    gDiskIoPrivateDataTemplate.BlockIo2 = NULL;\r
  }\r
\r
  //\r
  // Initialize the Disk IO device instance.\r
  //\r
  Instance = AllocateCopyPool (sizeof (DISK_IO_PRIVATE_DATA), &gDiskIoPrivateDataTemplate);\r
  if (Instance == NULL) {\r
    Status = EFI_OUT_OF_RESOURCES;\r
    goto ErrorExit;\r
  }\r
\r
  //\r
  // The BlockSize and IoAlign of BlockIo and BlockIo2 should equal.\r
  //\r
  ASSERT (\r
    (Instance->BlockIo2 == NULL) ||\r
    ((Instance->BlockIo->Media->IoAlign == Instance->BlockIo2->Media->IoAlign) &&\r
     (Instance->BlockIo->Media->BlockSize == Instance->BlockIo2->Media->BlockSize)\r
    )\r
    );\r
\r
  InitializeListHead (&Instance->TaskQueue);\r
  EfiInitializeLock (&Instance->TaskQueueLock, TPL_NOTIFY);\r
  Instance->SharedWorkingBuffer = AllocateAlignedPages (\r
                                    EFI_SIZE_TO_PAGES (PcdGet32 (PcdDiskIoDataBufferBlockNum) * Instance->BlockIo->Media->BlockSize),\r
                                    Instance->BlockIo->Media->IoAlign\r
                                    );\r
  if (Instance->SharedWorkingBuffer == NULL) {\r
    Status = EFI_OUT_OF_RESOURCES;\r
    goto ErrorExit;\r
  }\r
\r
  //\r
  // Install protocol interfaces for the Disk IO device.\r
  //\r
  if (Instance->BlockIo2 != NULL) {\r
    Status = gBS->InstallMultipleProtocolInterfaces (\r
                    &ControllerHandle,\r
                    &gEfiDiskIoProtocolGuid,\r
                    &Instance->DiskIo,\r
                    &gEfiDiskIo2ProtocolGuid,\r
                    &Instance->DiskIo2,\r
                    NULL\r
                    );\r
  } else {\r
    Status = gBS->InstallMultipleProtocolInterfaces (\r
                    &ControllerHandle,\r
                    &gEfiDiskIoProtocolGuid,\r
                    &Instance->DiskIo,\r
                    NULL\r
                    );\r
  }\r
\r
ErrorExit:\r
  if (EFI_ERROR (Status)) {\r
    if ((Instance != NULL) && (Instance->SharedWorkingBuffer != NULL)) {\r
      FreeAlignedPages (\r
        Instance->SharedWorkingBuffer,\r
        EFI_SIZE_TO_PAGES (PcdGet32 (PcdDiskIoDataBufferBlockNum) * Instance->BlockIo->Media->BlockSize)\r
        );\r
    }\r
\r
    if (Instance != NULL) {\r
      FreePool (Instance);\r
    }\r
\r
    gBS->CloseProtocol (\r
           ControllerHandle,\r
           &gEfiBlockIoProtocolGuid,\r
           This->DriverBindingHandle,\r
           ControllerHandle\r
           );\r
  }\r
\r
ErrorExit1:\r
  gBS->RestoreTPL (OldTpl);\r
  return Status;\r
}\r
\r
/**\r
  Stop this driver on ControllerHandle by removing Disk IO protocol and closing\r
  the Block IO protocol on ControllerHandle.\r
\r
  @param  This              Protocol instance pointer.\r
  @param  ControllerHandle  Handle of device to stop driver on\r
  @param  NumberOfChildren  Number of Handles in ChildHandleBuffer. If number of\r
                            children is zero stop the entire bus driver.\r
  @param  ChildHandleBuffer List of Child Handles to Stop.\r
\r
  @retval EFI_SUCCESS       This driver is removed ControllerHandle\r
  @retval other             This driver was not removed from this device\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
DiskIoDriverBindingStop (\r
  IN  EFI_DRIVER_BINDING_PROTOCOL  *This,\r
  IN  EFI_HANDLE                   ControllerHandle,\r
  IN  UINTN                        NumberOfChildren,\r
  IN  EFI_HANDLE                   *ChildHandleBuffer\r
  )\r
{\r
  EFI_STATUS             Status;\r
  EFI_DISK_IO_PROTOCOL   *DiskIo;\r
  EFI_DISK_IO2_PROTOCOL  *DiskIo2;\r
  DISK_IO_PRIVATE_DATA   *Instance;\r
  BOOLEAN                AllTaskDone;\r
\r
  //\r
  // Get our context back.\r
  //\r
  Status = gBS->OpenProtocol (\r
                  ControllerHandle,\r
                  &gEfiDiskIoProtocolGuid,\r
                  (VOID **)&DiskIo,\r
                  This->DriverBindingHandle,\r
                  ControllerHandle,\r
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  Status = gBS->OpenProtocol (\r
                  ControllerHandle,\r
                  &gEfiDiskIo2ProtocolGuid,\r
                  (VOID **)&DiskIo2,\r
                  This->DriverBindingHandle,\r
                  ControllerHandle,\r
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    DiskIo2 = NULL;\r
  }\r
\r
  Instance = DISK_IO_PRIVATE_DATA_FROM_DISK_IO (DiskIo);\r
\r
  if (DiskIo2 != NULL) {\r
    //\r
    // Call BlockIo2::Reset() to terminate any in-flight non-blocking I/O requests\r
    //\r
    ASSERT (Instance->BlockIo2 != NULL);\r
    Status = Instance->BlockIo2->Reset (Instance->BlockIo2, FALSE);\r
    if (EFI_ERROR (Status)) {\r
      return Status;\r
    }\r
\r
    Status = gBS->UninstallMultipleProtocolInterfaces (\r
                    ControllerHandle,\r
                    &gEfiDiskIoProtocolGuid,\r
                    &Instance->DiskIo,\r
                    &gEfiDiskIo2ProtocolGuid,\r
                    &Instance->DiskIo2,\r
                    NULL\r
                    );\r
  } else {\r
    Status = gBS->UninstallMultipleProtocolInterfaces (\r
                    ControllerHandle,\r
                    &gEfiDiskIoProtocolGuid,\r
                    &Instance->DiskIo,\r
                    NULL\r
                    );\r
  }\r
\r
  if (!EFI_ERROR (Status)) {\r
    do {\r
      EfiAcquireLock (&Instance->TaskQueueLock);\r
      AllTaskDone = IsListEmpty (&Instance->TaskQueue);\r
      EfiReleaseLock (&Instance->TaskQueueLock);\r
    } while (!AllTaskDone);\r
\r
    FreeAlignedPages (\r
      Instance->SharedWorkingBuffer,\r
      EFI_SIZE_TO_PAGES (PcdGet32 (PcdDiskIoDataBufferBlockNum) * Instance->BlockIo->Media->BlockSize)\r
      );\r
\r
    Status = gBS->CloseProtocol (\r
                    ControllerHandle,\r
                    &gEfiBlockIoProtocolGuid,\r
                    This->DriverBindingHandle,\r
                    ControllerHandle\r
                    );\r
    ASSERT_EFI_ERROR (Status);\r
    if (DiskIo2 != NULL) {\r
      Status = gBS->CloseProtocol (\r
                      ControllerHandle,\r
                      &gEfiBlockIo2ProtocolGuid,\r
                      This->DriverBindingHandle,\r
                      ControllerHandle\r
                      );\r
      ASSERT_EFI_ERROR (Status);\r
    }\r
\r
    FreePool (Instance);\r
  }\r
\r
  return Status;\r
}\r
\r
/**\r
  Destroy the sub task.\r
\r
  @param Instance     Pointer to the DISK_IO_PRIVATE_DATA.\r
  @param Subtask      Subtask.\r
\r
  @return LIST_ENTRY *  Pointer to the next link of subtask.\r
**/\r
LIST_ENTRY *\r
DiskIoDestroySubtask (\r
  IN DISK_IO_PRIVATE_DATA  *Instance,\r
  IN DISK_IO_SUBTASK       *Subtask\r
  )\r
{\r
  LIST_ENTRY  *Link;\r
\r
  if (Subtask->Task != NULL) {\r
    EfiAcquireLock (&Subtask->Task->SubtasksLock);\r
  }\r
\r
  Link = RemoveEntryList (&Subtask->Link);\r
  if (Subtask->Task != NULL) {\r
    EfiReleaseLock (&Subtask->Task->SubtasksLock);\r
  }\r
\r
  if (!Subtask->Blocking) {\r
    if (Subtask->WorkingBuffer != NULL) {\r
      FreeAlignedPages (\r
        Subtask->WorkingBuffer,\r
        Subtask->Length < Instance->BlockIo->Media->BlockSize\r
        ? EFI_SIZE_TO_PAGES (Instance->BlockIo->Media->BlockSize)\r
        : EFI_SIZE_TO_PAGES (Subtask->Length)\r
        );\r
    }\r
\r
    if (Subtask->BlockIo2Token.Event != NULL) {\r
      gBS->CloseEvent (Subtask->BlockIo2Token.Event);\r
    }\r
  }\r
\r
  FreePool (Subtask);\r
\r
  return Link;\r
}\r
\r
/**\r
  The callback for the BlockIo2 ReadBlocksEx/WriteBlocksEx.\r
  @param  Event                 Event whose notification function is being invoked.\r
  @param  Context               The pointer to the notification function's context,\r
                                which points to the DISK_IO_SUBTASK instance.\r
**/\r
VOID\r
EFIAPI\r
DiskIo2OnReadWriteComplete (\r
  IN EFI_EVENT  Event,\r
  IN VOID       *Context\r
  )\r
{\r
  DISK_IO_SUBTASK       *Subtask;\r
  DISK_IO2_TASK         *Task;\r
  EFI_STATUS            TransactionStatus;\r
  DISK_IO_PRIVATE_DATA  *Instance;\r
\r
  Subtask           = (DISK_IO_SUBTASK *)Context;\r
  TransactionStatus = Subtask->BlockIo2Token.TransactionStatus;\r
  Task              = Subtask->Task;\r
  Instance          = Task->Instance;\r
\r
  ASSERT (Subtask->Signature  == DISK_IO_SUBTASK_SIGNATURE);\r
  ASSERT (Instance->Signature == DISK_IO_PRIVATE_DATA_SIGNATURE);\r
  ASSERT (Task->Signature     == DISK_IO2_TASK_SIGNATURE);\r
\r
  if ((Subtask->WorkingBuffer != NULL) && !EFI_ERROR (TransactionStatus) &&\r
      (Task->Token != NULL) && !Subtask->Write\r
      )\r
  {\r
    CopyMem (Subtask->Buffer, Subtask->WorkingBuffer + Subtask->Offset, Subtask->Length);\r
  }\r
\r
  DiskIoDestroySubtask (Instance, Subtask);\r
\r
  if (EFI_ERROR (TransactionStatus) || IsListEmpty (&Task->Subtasks)) {\r
    if (Task->Token != NULL) {\r
      //\r
      // Signal error status once the subtask is failed.\r
      // Or signal the last status once the last subtask is finished.\r
      //\r
      Task->Token->TransactionStatus = TransactionStatus;\r
      gBS->SignalEvent (Task->Token->Event);\r
\r
      //\r
      // Mark token to NULL indicating the Task is a dead task.\r
      //\r
      Task->Token = NULL;\r
    }\r
  }\r
}\r
\r
/**\r
  Create the subtask.\r
\r
  @param Write         TRUE: Write request; FALSE: Read request.\r
  @param Lba           The starting logical block address to read from on the device.\r
  @param Offset        The starting byte offset to read from the LBA.\r
  @param Length        The number of bytes to read from the device.\r
  @param WorkingBuffer The aligned buffer to hold the data for reading or writing.\r
  @param Buffer        The buffer to hold the data for reading or writing.\r
  @param Blocking      TRUE: Blocking request; FALSE: Non-blocking request.\r
\r
  @return A pointer to the created subtask.\r
**/\r
DISK_IO_SUBTASK *\r
DiskIoCreateSubtask (\r
  IN BOOLEAN  Write,\r
  IN UINT64   Lba,\r
  IN UINT32   Offset,\r
  IN UINTN    Length,\r
  IN VOID     *WorkingBuffer   OPTIONAL,\r
  IN VOID     *Buffer,\r
  IN BOOLEAN  Blocking\r
  )\r
{\r
  DISK_IO_SUBTASK  *Subtask;\r
  EFI_STATUS       Status;\r
\r
  Subtask = AllocateZeroPool (sizeof (DISK_IO_SUBTASK));\r
  if (Subtask == NULL) {\r
    return NULL;\r
  }\r
\r
  Subtask->Signature     = DISK_IO_SUBTASK_SIGNATURE;\r
  Subtask->Write         = Write;\r
  Subtask->Lba           = Lba;\r
  Subtask->Offset        = Offset;\r
  Subtask->Length        = Length;\r
  Subtask->WorkingBuffer = WorkingBuffer;\r
  Subtask->Buffer        = Buffer;\r
  Subtask->Blocking      = Blocking;\r
  if (!Blocking) {\r
    Status = gBS->CreateEvent (\r
                    EVT_NOTIFY_SIGNAL,\r
                    TPL_NOTIFY,\r
                    DiskIo2OnReadWriteComplete,\r
                    Subtask,\r
                    &Subtask->BlockIo2Token.Event\r
                    );\r
    if (EFI_ERROR (Status)) {\r
      FreePool (Subtask);\r
      return NULL;\r
    }\r
  }\r
\r
  DEBUG ((\r
    DEBUG_BLKIO,\r
    "  %c:Lba/Offset/Length/WorkingBuffer/Buffer = %016lx/%08x/%08x/%08x/%08x\n",\r
    Write ? 'W' : 'R',\r
    Lba,\r
    Offset,\r
    Length,\r
    WorkingBuffer,\r
    Buffer\r
    ));\r
\r
  return Subtask;\r
}\r
\r
/**\r
  Create the subtask list.\r
\r
  @param Instance            Pointer to the DISK_IO_PRIVATE_DATA.\r
  @param Write               TRUE: Write request; FALSE: Read request.\r
  @param Offset              The starting byte offset to read from the device.\r
  @param BufferSize          The size in bytes of Buffer. The number of bytes to read from the device.\r
  @param Buffer              A pointer to the buffer for the data.\r
  @param Blocking            TRUE: Blocking request; FALSE: Non-blocking request.\r
  @param SharedWorkingBuffer The aligned buffer to hold the data for reading or writing.\r
  @param Subtasks            The subtask list header.\r
\r
  @retval TRUE  The subtask list is created successfully.\r
  @retval FALSE The subtask list is not created.\r
**/\r
BOOLEAN\r
DiskIoCreateSubtaskList (\r
  IN DISK_IO_PRIVATE_DATA  *Instance,\r
  IN BOOLEAN               Write,\r
  IN UINT64                Offset,\r
  IN UINTN                 BufferSize,\r
  IN VOID                  *Buffer,\r
  IN BOOLEAN               Blocking,\r
  IN VOID                  *SharedWorkingBuffer,\r
  IN OUT LIST_ENTRY        *Subtasks\r
  )\r
{\r
  UINT32           BlockSize;\r
  UINT32           IoAlign;\r
  UINT64           Lba;\r
  UINT64           OverRunLba;\r
  UINT32           UnderRun;\r
  UINT32           OverRun;\r
  UINT8            *BufferPtr;\r
  UINTN            Length;\r
  UINTN            DataBufferSize;\r
  DISK_IO_SUBTASK  *Subtask;\r
  VOID             *WorkingBuffer;\r
  LIST_ENTRY       *Link;\r
\r
  DEBUG ((DEBUG_BLKIO, "DiskIo: Create subtasks for task: Offset/BufferSize/Buffer = %016lx/%08x/%08x\n", Offset, BufferSize, Buffer));\r
\r
  BlockSize = Instance->BlockIo->Media->BlockSize;\r
  IoAlign   = Instance->BlockIo->Media->IoAlign;\r
  if (IoAlign == 0) {\r
    IoAlign = 1;\r
  }\r
\r
  Lba       = DivU64x32Remainder (Offset, BlockSize, &UnderRun);\r
  BufferPtr = (UINT8 *)Buffer;\r
\r
  //\r
  // Special handling for zero BufferSize\r
  //\r
  if (BufferSize == 0) {\r
    Subtask = DiskIoCreateSubtask (Write, Lba, UnderRun, 0, NULL, BufferPtr, Blocking);\r
    if (Subtask == NULL) {\r
      goto Done;\r
    }\r
\r
    InsertTailList (Subtasks, &Subtask->Link);\r
    return TRUE;\r
  }\r
\r
  if (UnderRun != 0) {\r
    Length = MIN (BlockSize - UnderRun, BufferSize);\r
    if (Blocking) {\r
      WorkingBuffer = SharedWorkingBuffer;\r
    } else {\r
      WorkingBuffer = AllocateAlignedPages (EFI_SIZE_TO_PAGES (BlockSize), IoAlign);\r
      if (WorkingBuffer == NULL) {\r
        goto Done;\r
      }\r
    }\r
\r
    if (Write) {\r
      //\r
      // A half write operation can be splitted to a blocking block-read and half write operation\r
      // This can simplify the sub task processing logic\r
      //\r
      Subtask = DiskIoCreateSubtask (FALSE, Lba, 0, BlockSize, NULL, WorkingBuffer, TRUE);\r
      if (Subtask == NULL) {\r
        goto Done;\r
      }\r
\r
      InsertTailList (Subtasks, &Subtask->Link);\r
    }\r
\r
    Subtask = DiskIoCreateSubtask (Write, Lba, UnderRun, Length, WorkingBuffer, BufferPtr, Blocking);\r
    if (Subtask == NULL) {\r
      goto Done;\r
    }\r
\r
    InsertTailList (Subtasks, &Subtask->Link);\r
\r
    BufferPtr  += Length;\r
    Offset     += Length;\r
    BufferSize -= Length;\r
    Lba++;\r
  }\r
\r
  OverRunLba  = Lba + DivU64x32Remainder (BufferSize, BlockSize, &OverRun);\r
  BufferSize -= OverRun;\r
\r
  if (OverRun != 0) {\r
    if (Blocking) {\r
      WorkingBuffer = SharedWorkingBuffer;\r
    } else {\r
      WorkingBuffer = AllocateAlignedPages (EFI_SIZE_TO_PAGES (BlockSize), IoAlign);\r
      if (WorkingBuffer == NULL) {\r
        goto Done;\r
      }\r
    }\r
\r
    if (Write) {\r
      //\r
      // A half write operation can be splitted to a blocking block-read and half write operation\r
      // This can simplify the sub task processing logic\r
      //\r
      Subtask = DiskIoCreateSubtask (FALSE, OverRunLba, 0, BlockSize, NULL, WorkingBuffer, TRUE);\r
      if (Subtask == NULL) {\r
        goto Done;\r
      }\r
\r
      InsertTailList (Subtasks, &Subtask->Link);\r
    }\r
\r
    Subtask = DiskIoCreateSubtask (Write, OverRunLba, 0, OverRun, WorkingBuffer, BufferPtr + BufferSize, Blocking);\r
    if (Subtask == NULL) {\r
      goto Done;\r
    }\r
\r
    InsertTailList (Subtasks, &Subtask->Link);\r
  }\r
\r
  if (OverRunLba > Lba) {\r
    //\r
    // If the DiskIo maps directly to a BlockIo device do the read.\r
    //\r
    if (ALIGN_POINTER (BufferPtr, IoAlign) == BufferPtr) {\r
      Subtask = DiskIoCreateSubtask (Write, Lba, 0, BufferSize, NULL, BufferPtr, Blocking);\r
      if (Subtask == NULL) {\r
        goto Done;\r
      }\r
\r
      InsertTailList (Subtasks, &Subtask->Link);\r
\r
      BufferPtr  += BufferSize;\r
      Offset     += BufferSize;\r
      BufferSize -= BufferSize;\r
    } else {\r
      if (Blocking) {\r
        //\r
        // Use the allocated buffer instead of the original buffer\r
        // to avoid alignment issue.\r
        //\r
        for ( ; Lba < OverRunLba; Lba += PcdGet32 (PcdDiskIoDataBufferBlockNum)) {\r
          DataBufferSize = MIN (BufferSize, PcdGet32 (PcdDiskIoDataBufferBlockNum) * BlockSize);\r
\r
          Subtask = DiskIoCreateSubtask (Write, Lba, 0, DataBufferSize, SharedWorkingBuffer, BufferPtr, Blocking);\r
          if (Subtask == NULL) {\r
            goto Done;\r
          }\r
\r
          InsertTailList (Subtasks, &Subtask->Link);\r
\r
          BufferPtr  += DataBufferSize;\r
          Offset     += DataBufferSize;\r
          BufferSize -= DataBufferSize;\r
        }\r
      } else {\r
        WorkingBuffer = AllocateAlignedPages (EFI_SIZE_TO_PAGES (BufferSize), IoAlign);\r
        if (WorkingBuffer == NULL) {\r
          //\r
          // If there is not enough memory, downgrade to blocking access\r
          //\r
          DEBUG ((DEBUG_VERBOSE, "DiskIo: No enough memory so downgrade to blocking access\n"));\r
          if (!DiskIoCreateSubtaskList (Instance, Write, Offset, BufferSize, BufferPtr, TRUE, SharedWorkingBuffer, Subtasks)) {\r
            goto Done;\r
          }\r
        } else {\r
          Subtask = DiskIoCreateSubtask (Write, Lba, 0, BufferSize, WorkingBuffer, BufferPtr, Blocking);\r
          if (Subtask == NULL) {\r
            goto Done;\r
          }\r
\r
          InsertTailList (Subtasks, &Subtask->Link);\r
        }\r
\r
        BufferPtr  += BufferSize;\r
        Offset     += BufferSize;\r
        BufferSize -= BufferSize;\r
      }\r
    }\r
  }\r
\r
  ASSERT (BufferSize == 0);\r
\r
  return TRUE;\r
\r
Done:\r
  //\r
  // Remove all the subtasks.\r
  //\r
  for (Link = GetFirstNode (Subtasks); !IsNull (Subtasks, Link); ) {\r
    Subtask = CR (Link, DISK_IO_SUBTASK, Link, DISK_IO_SUBTASK_SIGNATURE);\r
    Link    = DiskIoDestroySubtask (Instance, Subtask);\r
  }\r
\r
  return FALSE;\r
}\r
\r
/**\r
  Terminate outstanding asynchronous requests to a device.\r
\r
  @param This                   Indicates a pointer to the calling context.\r
\r
  @retval EFI_SUCCESS           All outstanding requests were successfully terminated.\r
  @retval EFI_DEVICE_ERROR      The device reported an error while performing the cancel\r
                                operation.\r
**/\r
EFI_STATUS\r
EFIAPI\r
DiskIo2Cancel (\r
  IN EFI_DISK_IO2_PROTOCOL  *This\r
  )\r
{\r
  DISK_IO_PRIVATE_DATA  *Instance;\r
  DISK_IO2_TASK         *Task;\r
  LIST_ENTRY            *Link;\r
\r
  Instance = DISK_IO_PRIVATE_DATA_FROM_DISK_IO2 (This);\r
\r
  EfiAcquireLock (&Instance->TaskQueueLock);\r
\r
  for (Link = GetFirstNode (&Instance->TaskQueue)\r
       ; !IsNull (&Instance->TaskQueue, Link)\r
       ; Link = GetNextNode (&Instance->TaskQueue, Link)\r
       )\r
  {\r
    Task = CR (Link, DISK_IO2_TASK, Link, DISK_IO2_TASK_SIGNATURE);\r
\r
    if (Task->Token != NULL) {\r
      Task->Token->TransactionStatus = EFI_ABORTED;\r
      gBS->SignalEvent (Task->Token->Event);\r
      //\r
      // Set Token to NULL so that the further BlockIo2 responses will be ignored\r
      //\r
      Task->Token = NULL;\r
    }\r
  }\r
\r
  EfiReleaseLock (&Instance->TaskQueueLock);\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Remove the completed tasks from Instance->TaskQueue. Completed tasks are those who don't have any subtasks.\r
\r
  @param Instance    Pointer to the DISK_IO_PRIVATE_DATA.\r
\r
  @retval TRUE       The Instance->TaskQueue is empty after the completed tasks are removed.\r
  @retval FALSE      The Instance->TaskQueue is not empty after the completed tasks are removed.\r
**/\r
BOOLEAN\r
DiskIo2RemoveCompletedTask (\r
  IN DISK_IO_PRIVATE_DATA  *Instance\r
  )\r
{\r
  BOOLEAN        QueueEmpty;\r
  LIST_ENTRY     *Link;\r
  DISK_IO2_TASK  *Task;\r
\r
  QueueEmpty = TRUE;\r
\r
  EfiAcquireLock (&Instance->TaskQueueLock);\r
  for (Link = GetFirstNode (&Instance->TaskQueue); !IsNull (&Instance->TaskQueue, Link); ) {\r
    Task = CR (Link, DISK_IO2_TASK, Link, DISK_IO2_TASK_SIGNATURE);\r
    if (IsListEmpty (&Task->Subtasks)) {\r
      Link = RemoveEntryList (&Task->Link);\r
      ASSERT (Task->Token == NULL);\r
      FreePool (Task);\r
    } else {\r
      Link       = GetNextNode (&Instance->TaskQueue, Link);\r
      QueueEmpty = FALSE;\r
    }\r
  }\r
\r
  EfiReleaseLock (&Instance->TaskQueueLock);\r
\r
  return QueueEmpty;\r
}\r
\r
/**\r
  Common routine to access the disk.\r
\r
  @param Instance    Pointer to the DISK_IO_PRIVATE_DATA.\r
  @param Write       TRUE: Write operation; FALSE: Read operation.\r
  @param MediaId     ID of the medium to access.\r
  @param Offset      The starting byte offset on the logical block I/O device to access.\r
  @param Token       A pointer to the token associated with the transaction.\r
                     If this field is NULL, synchronous/blocking IO is performed.\r
  @param  BufferSize            The size in bytes of Buffer. The number of bytes to read from the device.\r
  @param  Buffer                A pointer to the destination buffer for the data.\r
                                The caller is responsible either having implicit or explicit ownership of the buffer.\r
**/\r
EFI_STATUS\r
DiskIo2ReadWriteDisk (\r
  IN DISK_IO_PRIVATE_DATA  *Instance,\r
  IN BOOLEAN               Write,\r
  IN UINT32                MediaId,\r
  IN UINT64                Offset,\r
  IN EFI_DISK_IO2_TOKEN    *Token,\r
  IN UINTN                 BufferSize,\r
  IN UINT8                 *Buffer\r
  )\r
{\r
  EFI_STATUS              Status;\r
  EFI_BLOCK_IO_PROTOCOL   *BlockIo;\r
  EFI_BLOCK_IO2_PROTOCOL  *BlockIo2;\r
  EFI_BLOCK_IO_MEDIA      *Media;\r
  LIST_ENTRY              *Link;\r
  LIST_ENTRY              *NextLink;\r
  LIST_ENTRY              Subtasks;\r
  DISK_IO_SUBTASK         *Subtask;\r
  DISK_IO2_TASK           *Task;\r
  EFI_TPL                 OldTpl;\r
  BOOLEAN                 Blocking;\r
  BOOLEAN                 SubtaskBlocking;\r
  LIST_ENTRY              *SubtasksPtr;\r
\r
  Task     = NULL;\r
  BlockIo  = Instance->BlockIo;\r
  BlockIo2 = Instance->BlockIo2;\r
  Media    = BlockIo->Media;\r
  Status   = EFI_SUCCESS;\r
  Blocking = (BOOLEAN)((Token == NULL) || (Token->Event == NULL));\r
\r
  if (Blocking) {\r
    //\r
    // Wait till pending async task is completed.\r
    //\r
    while (!DiskIo2RemoveCompletedTask (Instance)) {\r
    }\r
\r
    SubtasksPtr = &Subtasks;\r
  } else {\r
    DiskIo2RemoveCompletedTask (Instance);\r
    Task = AllocatePool (sizeof (DISK_IO2_TASK));\r
    if (Task == NULL) {\r
      return EFI_OUT_OF_RESOURCES;\r
    }\r
\r
    EfiAcquireLock (&Instance->TaskQueueLock);\r
    InsertTailList (&Instance->TaskQueue, &Task->Link);\r
    EfiReleaseLock (&Instance->TaskQueueLock);\r
\r
    Task->Signature = DISK_IO2_TASK_SIGNATURE;\r
    Task->Instance  = Instance;\r
    Task->Token     = Token;\r
    EfiInitializeLock (&Task->SubtasksLock, TPL_NOTIFY);\r
\r
    SubtasksPtr = &Task->Subtasks;\r
  }\r
\r
  InitializeListHead (SubtasksPtr);\r
  if (!DiskIoCreateSubtaskList (Instance, Write, Offset, BufferSize, Buffer, Blocking, Instance->SharedWorkingBuffer, SubtasksPtr)) {\r
    if (Task != NULL) {\r
      FreePool (Task);\r
    }\r
\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
\r
  ASSERT (!IsListEmpty (SubtasksPtr));\r
\r
  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);\r
  for ( Link = GetFirstNode (SubtasksPtr), NextLink = GetNextNode (SubtasksPtr, Link)\r
        ; !IsNull (SubtasksPtr, Link)\r
        ; Link = NextLink, NextLink = GetNextNode (SubtasksPtr, NextLink)\r
        )\r
  {\r
    Subtask         = CR (Link, DISK_IO_SUBTASK, Link, DISK_IO_SUBTASK_SIGNATURE);\r
    Subtask->Task   = Task;\r
    SubtaskBlocking = Subtask->Blocking;\r
\r
    ASSERT ((Subtask->Length % Media->BlockSize == 0) || (Subtask->Length < Media->BlockSize));\r
\r
    if (Subtask->Write) {\r
      //\r
      // Write\r
      //\r
      if (Subtask->WorkingBuffer != NULL) {\r
        //\r
        // A sub task before this one should be a block read operation, causing the WorkingBuffer filled with the entire one block data.\r
        //\r
        CopyMem (Subtask->WorkingBuffer + Subtask->Offset, Subtask->Buffer, Subtask->Length);\r
      }\r
\r
      if (SubtaskBlocking) {\r
        Status = BlockIo->WriteBlocks (\r
                            BlockIo,\r
                            MediaId,\r
                            Subtask->Lba,\r
                            (Subtask->Length % Media->BlockSize == 0) ? Subtask->Length : Media->BlockSize,\r
                            (Subtask->WorkingBuffer != NULL) ? Subtask->WorkingBuffer : Subtask->Buffer\r
                            );\r
      } else {\r
        Status = BlockIo2->WriteBlocksEx (\r
                             BlockIo2,\r
                             MediaId,\r
                             Subtask->Lba,\r
                             &Subtask->BlockIo2Token,\r
                             (Subtask->Length % Media->BlockSize == 0) ? Subtask->Length : Media->BlockSize,\r
                             (Subtask->WorkingBuffer != NULL) ? Subtask->WorkingBuffer : Subtask->Buffer\r
                             );\r
      }\r
    } else {\r
      //\r
      // Read\r
      //\r
      if (SubtaskBlocking) {\r
        Status = BlockIo->ReadBlocks (\r
                            BlockIo,\r
                            MediaId,\r
                            Subtask->Lba,\r
                            (Subtask->Length % Media->BlockSize == 0) ? Subtask->Length : Media->BlockSize,\r
                            (Subtask->WorkingBuffer != NULL) ? Subtask->WorkingBuffer : Subtask->Buffer\r
                            );\r
        if (!EFI_ERROR (Status) && (Subtask->WorkingBuffer != NULL)) {\r
          CopyMem (Subtask->Buffer, Subtask->WorkingBuffer + Subtask->Offset, Subtask->Length);\r
        }\r
      } else {\r
        Status = BlockIo2->ReadBlocksEx (\r
                             BlockIo2,\r
                             MediaId,\r
                             Subtask->Lba,\r
                             &Subtask->BlockIo2Token,\r
                             (Subtask->Length % Media->BlockSize == 0) ? Subtask->Length : Media->BlockSize,\r
                             (Subtask->WorkingBuffer != NULL) ? Subtask->WorkingBuffer : Subtask->Buffer\r
                             );\r
      }\r
    }\r
\r
    if (SubtaskBlocking || EFI_ERROR (Status)) {\r
      //\r
      // Make sure the subtask list only contains non-blocking subtasks.\r
      // Remove failed non-blocking subtasks as well because the callback won't be called.\r
      //\r
      DiskIoDestroySubtask (Instance, Subtask);\r
    }\r
\r
    if (EFI_ERROR (Status)) {\r
      break;\r
    }\r
  }\r
\r
  gBS->RaiseTPL (TPL_NOTIFY);\r
\r
  //\r
  // Remove all the remaining subtasks when failure.\r
  // We shouldn't remove all the tasks because the non-blocking requests have been submitted and cannot be canceled.\r
  //\r
  if (EFI_ERROR (Status)) {\r
    while (!IsNull (SubtasksPtr, NextLink)) {\r
      Subtask  = CR (NextLink, DISK_IO_SUBTASK, Link, DISK_IO_SUBTASK_SIGNATURE);\r
      NextLink = DiskIoDestroySubtask (Instance, Subtask);\r
    }\r
  }\r
\r
  //\r
  // It's possible that the non-blocking subtasks finish before raising TPL to NOTIFY,\r
  // so the subtasks list might be empty at this point.\r
  //\r
  if (!Blocking && IsListEmpty (SubtasksPtr)) {\r
    EfiAcquireLock (&Instance->TaskQueueLock);\r
    RemoveEntryList (&Task->Link);\r
    EfiReleaseLock (&Instance->TaskQueueLock);\r
\r
    if (!EFI_ERROR (Status) && (Task->Token != NULL)) {\r
      //\r
      // Task->Token should be set to NULL by the DiskIo2OnReadWriteComplete\r
      // It it's not, that means the non-blocking request was downgraded to blocking request.\r
      //\r
      DEBUG ((DEBUG_VERBOSE, "DiskIo: Non-blocking request was downgraded to blocking request, signal event directly.\n"));\r
      Task->Token->TransactionStatus = Status;\r
      gBS->SignalEvent (Task->Token->Event);\r
    }\r
\r
    FreePool (Task);\r
  }\r
\r
  gBS->RestoreTPL (OldTpl);\r
\r
  return Status;\r
}\r
\r
/**\r
  Reads a specified number of bytes from a device.\r
\r
  @param This                   Indicates a pointer to the calling context.\r
  @param MediaId                ID of the medium to be read.\r
  @param Offset                 The starting byte offset on the logical block I/O device to read from.\r
  @param Token                  A pointer to the token associated with the transaction.\r
                                If this field is NULL, synchronous/blocking IO is performed.\r
  @param  BufferSize            The size in bytes of Buffer. The number of bytes to read from the device.\r
  @param  Buffer                A pointer to the destination buffer for the data.\r
                                The caller is responsible either having implicit or explicit ownership of the buffer.\r
\r
  @retval EFI_SUCCESS           If Event is NULL (blocking I/O): The data was read correctly from the device.\r
                                If Event is not NULL (asynchronous I/O): The request was successfully queued for processing.\r
                                                                         Event will be signaled upon completion.\r
  @retval EFI_DEVICE_ERROR      The device reported an error while performing the write.\r
  @retval EFI_NO_MEDIA          There is no medium in the device.\r
  @retval EFI_MEDIA_CHNAGED     The MediaId is not for the current medium.\r
  @retval EFI_INVALID_PARAMETER The read request contains device addresses that are not valid for the device.\r
  @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a lack of resources.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
DiskIo2ReadDiskEx (\r
  IN EFI_DISK_IO2_PROTOCOL   *This,\r
  IN UINT32                  MediaId,\r
  IN UINT64                  Offset,\r
  IN OUT EFI_DISK_IO2_TOKEN  *Token,\r
  IN UINTN                   BufferSize,\r
  OUT VOID                   *Buffer\r
  )\r
{\r
  return DiskIo2ReadWriteDisk (\r
           DISK_IO_PRIVATE_DATA_FROM_DISK_IO2 (This),\r
           FALSE,\r
           MediaId,\r
           Offset,\r
           Token,\r
           BufferSize,\r
           (UINT8 *)Buffer\r
           );\r
}\r
\r
/**\r
  Writes a specified number of bytes to a device.\r
\r
  @param This        Indicates a pointer to the calling context.\r
  @param MediaId     ID of the medium to be written.\r
  @param Offset      The starting byte offset on the logical block I/O device to write to.\r
  @param Token       A pointer to the token associated with the transaction.\r
                     If this field is NULL, synchronous/blocking IO is performed.\r
  @param BufferSize  The size in bytes of Buffer. The number of bytes to write to the device.\r
  @param Buffer      A pointer to the buffer containing the data to be written.\r
\r
  @retval EFI_SUCCESS           If Event is NULL (blocking I/O): The data was written correctly to the device.\r
                                If Event is not NULL (asynchronous I/O): The request was successfully queued for processing.\r
                                                                         Event will be signaled upon completion.\r
  @retval EFI_WRITE_PROTECTED   The device cannot be written to.\r
  @retval EFI_DEVICE_ERROR      The device reported an error while performing the write operation.\r
  @retval EFI_NO_MEDIA          There is no medium in the device.\r
  @retval EFI_MEDIA_CHNAGED     The MediaId is not for the current medium.\r
  @retval EFI_INVALID_PARAMETER The write request contains device addresses that are not valid for the device.\r
  @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a lack of resources.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
DiskIo2WriteDiskEx (\r
  IN EFI_DISK_IO2_PROTOCOL   *This,\r
  IN UINT32                  MediaId,\r
  IN UINT64                  Offset,\r
  IN OUT EFI_DISK_IO2_TOKEN  *Token,\r
  IN UINTN                   BufferSize,\r
  IN VOID                    *Buffer\r
  )\r
{\r
  return DiskIo2ReadWriteDisk (\r
           DISK_IO_PRIVATE_DATA_FROM_DISK_IO2 (This),\r
           TRUE,\r
           MediaId,\r
           Offset,\r
           Token,\r
           BufferSize,\r
           (UINT8 *)Buffer\r
           );\r
}\r
\r
/**\r
  The callback for the BlockIo2 FlushBlocksEx.\r
  @param  Event                 Event whose notification function is being invoked.\r
  @param  Context               The pointer to the notification function's context,\r
                                which points to the DISK_IO2_FLUSH_TASK instance.\r
**/\r
VOID\r
EFIAPI\r
DiskIo2OnFlushComplete (\r
  IN EFI_EVENT  Event,\r
  IN VOID       *Context\r
  )\r
{\r
  DISK_IO2_FLUSH_TASK  *Task;\r
\r
  gBS->CloseEvent (Event);\r
\r
  Task = (DISK_IO2_FLUSH_TASK *)Context;\r
  ASSERT (Task->Signature == DISK_IO2_FLUSH_TASK_SIGNATURE);\r
  Task->Token->TransactionStatus = Task->BlockIo2Token.TransactionStatus;\r
  gBS->SignalEvent (Task->Token->Event);\r
\r
  FreePool (Task);\r
}\r
\r
/**\r
  Flushes all modified data to the physical device.\r
\r
  @param This        Indicates a pointer to the calling context.\r
  @param Token       A pointer to the token associated with the transaction.\r
                     If this field is NULL, synchronous/blocking IO is performed.\r
\r
  @retval EFI_SUCCESS           If Event is NULL (blocking I/O): The data was flushed successfully to the device.\r
                                If Event is not NULL (asynchronous I/O): The request was successfully queued for processing.\r
                                                                         Event will be signaled upon completion.\r
  @retval EFI_WRITE_PROTECTED   The device cannot be written to.\r
  @retval EFI_DEVICE_ERROR      The device reported an error while performing the write operation.\r
  @retval EFI_NO_MEDIA          There is no medium in the device.\r
  @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a lack of resources.\r
**/\r
EFI_STATUS\r
EFIAPI\r
DiskIo2FlushDiskEx (\r
  IN EFI_DISK_IO2_PROTOCOL   *This,\r
  IN OUT EFI_DISK_IO2_TOKEN  *Token\r
  )\r
{\r
  EFI_STATUS            Status;\r
  DISK_IO2_FLUSH_TASK   *Task;\r
  DISK_IO_PRIVATE_DATA  *Private;\r
\r
  Private = DISK_IO_PRIVATE_DATA_FROM_DISK_IO2 (This);\r
\r
  if ((Token != NULL) && (Token->Event != NULL)) {\r
    Task = AllocatePool (sizeof (DISK_IO2_FLUSH_TASK));\r
    if (Task == NULL) {\r
      return EFI_OUT_OF_RESOURCES;\r
    }\r
\r
    Status = gBS->CreateEvent (\r
                    EVT_NOTIFY_SIGNAL,\r
                    TPL_CALLBACK,\r
                    DiskIo2OnFlushComplete,\r
                    Task,\r
                    &Task->BlockIo2Token.Event\r
                    );\r
    if (EFI_ERROR (Status)) {\r
      FreePool (Task);\r
      return Status;\r
    }\r
\r
    Task->Signature = DISK_IO2_FLUSH_TASK_SIGNATURE;\r
    Task->Token     = Token;\r
    Status          = Private->BlockIo2->FlushBlocksEx (Private->BlockIo2, &Task->BlockIo2Token);\r
    if (EFI_ERROR (Status)) {\r
      gBS->CloseEvent (Task->BlockIo2Token.Event);\r
      FreePool (Task);\r
    }\r
  } else {\r
    Status = Private->BlockIo2->FlushBlocksEx (Private->BlockIo2, NULL);\r
  }\r
\r
  return Status;\r
}\r
\r
/**\r
  Read BufferSize bytes from Offset into Buffer.\r
  Reads may support reads that are not aligned on\r
  sector boundaries. There are three cases:\r
    UnderRun - The first byte is not on a sector boundary or the read request is\r
               less than a sector in length.\r
    Aligned  - A read of N contiguous sectors.\r
    OverRun  - The last byte is not on a sector boundary.\r
\r
  @param  This                  Protocol instance pointer.\r
  @param  MediaId               Id of the media, changes every time the media is replaced.\r
  @param  Offset                The starting byte offset to read from\r
  @param  BufferSize            Size of Buffer\r
  @param  Buffer                Buffer containing read data\r
\r
  @retval EFI_SUCCESS           The data was read correctly from the device.\r
  @retval EFI_DEVICE_ERROR      The device reported an error while performing the read.\r
  @retval EFI_NO_MEDIA          There is no media in the device.\r
  @retval EFI_MEDIA_CHNAGED     The MediaId does not matched the current device.\r
  @retval EFI_INVALID_PARAMETER The read request contains device addresses that are not\r
                                valid for the device.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
DiskIoReadDisk (\r
  IN EFI_DISK_IO_PROTOCOL  *This,\r
  IN UINT32                MediaId,\r
  IN UINT64                Offset,\r
  IN UINTN                 BufferSize,\r
  OUT VOID                 *Buffer\r
  )\r
{\r
  return DiskIo2ReadWriteDisk (\r
           DISK_IO_PRIVATE_DATA_FROM_DISK_IO (This),\r
           FALSE,\r
           MediaId,\r
           Offset,\r
           NULL,\r
           BufferSize,\r
           (UINT8 *)Buffer\r
           );\r
}\r
\r
/**\r
  Writes BufferSize bytes from Buffer into Offset.\r
  Writes may require a read modify write to support writes that are not\r
  aligned on sector boundaries. There are three cases:\r
    UnderRun - The first byte is not on a sector boundary or the write request\r
               is less than a sector in length. Read modify write is required.\r
    Aligned  - A write of N contiguous sectors.\r
    OverRun  - The last byte is not on a sector boundary. Read modified write\r
               required.\r
\r
  @param  This       Protocol instance pointer.\r
  @param  MediaId    Id of the media, changes every time the media is replaced.\r
  @param  Offset     The starting byte offset to read from\r
  @param  BufferSize Size of Buffer\r
  @param  Buffer     Buffer containing read data\r
\r
  @retval EFI_SUCCESS           The data was written correctly to the device.\r
  @retval EFI_WRITE_PROTECTED   The device can not be written to.\r
  @retval EFI_DEVICE_ERROR      The device reported an error while performing the write.\r
  @retval EFI_NO_MEDIA          There is no media in the device.\r
  @retval EFI_MEDIA_CHNAGED     The MediaId does not matched the current device.\r
  @retval EFI_INVALID_PARAMETER The write request contains device addresses that are not\r
                                 valid for the device.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
DiskIoWriteDisk (\r
  IN EFI_DISK_IO_PROTOCOL  *This,\r
  IN UINT32                MediaId,\r
  IN UINT64                Offset,\r
  IN UINTN                 BufferSize,\r
  IN VOID                  *Buffer\r
  )\r
{\r
  return DiskIo2ReadWriteDisk (\r
           DISK_IO_PRIVATE_DATA_FROM_DISK_IO (This),\r
           TRUE,\r
           MediaId,\r
           Offset,\r
           NULL,\r
           BufferSize,\r
           (UINT8 *)Buffer\r
           );\r
}\r
\r
/**\r
  The user Entry Point for module DiskIo. The user code starts with this function.\r
\r
  @param[in] ImageHandle    The firmware allocated handle for the EFI image.\r
  @param[in] SystemTable    A pointer to the EFI System Table.\r
\r
  @retval EFI_SUCCESS       The entry point is executed successfully.\r
  @retval other             Some error occurs when executing this entry point.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
InitializeDiskIo (\r
  IN EFI_HANDLE        ImageHandle,\r
  IN EFI_SYSTEM_TABLE  *SystemTable\r
  )\r
{\r
  EFI_STATUS  Status;\r
\r
  //\r
  // Install driver model protocol(s).\r
  //\r
  Status = EfiLibInstallDriverBindingComponentName2 (\r
             ImageHandle,\r
             SystemTable,\r
             &gDiskIoDriverBinding,\r
             ImageHandle,\r
             &gDiskIoComponentName,\r
             &gDiskIoComponentName2\r
             );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  return Status;\r
}\r