DriverSupport.c

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#include "DxeMain.h"
#include "Handle.h"
 
//
// Driver Support Functions
//
 
EFI_STATUS
EFIAPI
CoreConnectController (
  IN  EFI_HANDLE                ControllerHandle,
  IN  EFI_HANDLE                *DriverImageHandle    OPTIONAL,
  IN  EFI_DEVICE_PATH_PROTOCOL  *RemainingDevicePath  OPTIONAL,
  IN  BOOLEAN                   Recursive
  )
{
  EFI_STATUS                Status;
  EFI_STATUS                ReturnStatus;
  IHANDLE                   *Handle;
  PROTOCOL_INTERFACE        *Prot;
  LIST_ENTRY                *Link;
  LIST_ENTRY                *ProtLink;
  OPEN_PROTOCOL_DATA        *OpenData;
  EFI_DEVICE_PATH_PROTOCOL  *AlignedRemainingDevicePath;
  EFI_HANDLE                *ChildHandleBuffer;
  UINTN                     ChildHandleCount;
  UINTN                     Index;
  UINTN                     HandleFilePathSize;
  UINTN                     RemainingDevicePathSize;
  EFI_DEVICE_PATH_PROTOCOL  *HandleFilePath;
  EFI_DEVICE_PATH_PROTOCOL  *FilePath;
  EFI_DEVICE_PATH_PROTOCOL  *TempFilePath;
 
  //
  // Make sure ControllerHandle is valid
  //
  CoreAcquireProtocolLock ();
 
  Status = CoreValidateHandle (ControllerHandle);
 
  CoreReleaseProtocolLock ();
 
  if (EFI_ERROR (Status)) {
    return Status;
  }
 
  if (gSecurity2 != NULL) {
    //
    // Check whether the user has permission to start UEFI device drivers.
    //
    Status = CoreHandleProtocol (ControllerHandle, &gEfiDevicePathProtocolGuid, (VOID **)&HandleFilePath);
    if (!EFI_ERROR (Status)) {
      ASSERT (HandleFilePath != NULL);
      FilePath     = HandleFilePath;
      TempFilePath = NULL;
      if ((RemainingDevicePath != NULL) && !Recursive) {
        HandleFilePathSize      = GetDevicePathSize (HandleFilePath) - sizeof (EFI_DEVICE_PATH_PROTOCOL);
        RemainingDevicePathSize = GetDevicePathSize (RemainingDevicePath);
        TempFilePath            = AllocateZeroPool (HandleFilePathSize + RemainingDevicePathSize);
        ASSERT (TempFilePath != NULL);
        CopyMem (TempFilePath, HandleFilePath, HandleFilePathSize);
        CopyMem ((UINT8 *)TempFilePath + HandleFilePathSize, RemainingDevicePath, RemainingDevicePathSize);
        FilePath = TempFilePath;
      }
 
      Status = gSecurity2->FileAuthentication (
                             gSecurity2,
                             FilePath,
                             NULL,
                             0,
                             FALSE
                             );
      if (TempFilePath != NULL) {
        FreePool (TempFilePath);
      }
 
      if (EFI_ERROR (Status)) {
        return Status;
      }
    }
  }
 
  Handle = ControllerHandle;
 
  //
  // Make a copy of RemainingDevicePath to guanatee it is aligned
  //
  AlignedRemainingDevicePath = NULL;
  if (RemainingDevicePath != NULL) {
    AlignedRemainingDevicePath = DuplicateDevicePath (RemainingDevicePath);
 
    if (AlignedRemainingDevicePath == NULL) {
      return EFI_OUT_OF_RESOURCES;
    }
  }
 
  //
  // Connect all drivers to ControllerHandle
  // If CoreConnectSingleController returns EFI_NOT_READY, then the number of
  // Driver Binding Protocols in the handle database has increased during the call
  // so the connect operation must be restarted
  //
  do {
    ReturnStatus = CoreConnectSingleController (
                     ControllerHandle,
                     DriverImageHandle,
                     AlignedRemainingDevicePath
                     );
  } while (ReturnStatus == EFI_NOT_READY);
 
  //
  // Free the aligned copy of RemainingDevicePath
  //
  if (AlignedRemainingDevicePath != NULL) {
    CoreFreePool (AlignedRemainingDevicePath);
  }
 
  //
  // If recursive, then connect all drivers to all of ControllerHandle's children
  //
  if (Recursive) {
    //
    // Acquire the protocol lock on the handle database so the child handles can be collected
    //
    CoreAcquireProtocolLock ();
 
    //
    // Make sure the DriverBindingHandle is valid
    //
    Status = CoreValidateHandle (ControllerHandle);
    if (EFI_ERROR (Status)) {
      //
      // Release the protocol lock on the handle database
      //
      CoreReleaseProtocolLock ();
 
      return ReturnStatus;
    }
 
    //
    // Count ControllerHandle's children
    //
    for (Link = Handle->Protocols.ForwardLink, ChildHandleCount = 0; Link != &Handle->Protocols; Link = Link->ForwardLink) {
      Prot = CR (Link, PROTOCOL_INTERFACE, Link, PROTOCOL_INTERFACE_SIGNATURE);
      for (ProtLink = Prot->OpenList.ForwardLink;
           ProtLink != &Prot->OpenList;
           ProtLink = ProtLink->ForwardLink)
      {
        OpenData = CR (ProtLink, OPEN_PROTOCOL_DATA, Link, OPEN_PROTOCOL_DATA_SIGNATURE);
        if ((OpenData->Attributes & EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) != 0) {
          ChildHandleCount++;
        }
      }
    }
 
    //
    // Allocate a handle buffer for ControllerHandle's children
    //
    ChildHandleBuffer = AllocatePool (ChildHandleCount * sizeof (EFI_HANDLE));
    if (ChildHandleBuffer == NULL) {
      CoreReleaseProtocolLock ();
      return EFI_OUT_OF_RESOURCES;
    }
 
    //
    // Fill in a handle buffer with ControllerHandle's children
    //
    for (Link = Handle->Protocols.ForwardLink, ChildHandleCount = 0; Link != &Handle->Protocols; Link = Link->ForwardLink) {
      Prot = CR (Link, PROTOCOL_INTERFACE, Link, PROTOCOL_INTERFACE_SIGNATURE);
      for (ProtLink = Prot->OpenList.ForwardLink;
           ProtLink != &Prot->OpenList;
           ProtLink = ProtLink->ForwardLink)
      {
        OpenData = CR (ProtLink, OPEN_PROTOCOL_DATA, Link, OPEN_PROTOCOL_DATA_SIGNATURE);
        if ((OpenData->Attributes & EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) != 0) {
          ChildHandleBuffer[ChildHandleCount] = OpenData->ControllerHandle;
          ChildHandleCount++;
        }
      }
    }
 
    //
    // Release the protocol lock on the handle database
    //
    CoreReleaseProtocolLock ();
 
    //
    // Recursively connect each child handle
    //
    for (Index = 0; Index < ChildHandleCount; Index++) {
      CoreConnectController (
        ChildHandleBuffer[Index],
        NULL,
        NULL,
        TRUE
        );
    }
 
    //
    // Free the handle buffer of ControllerHandle's children
    //
    CoreFreePool (ChildHandleBuffer);
  }
 
  return ReturnStatus;
}
 
VOID
AddSortedDriverBindingProtocol (
  IN      EFI_HANDLE                   DriverBindingHandle,
  IN OUT  UINTN                        *NumberOfSortedDriverBindingProtocols,
  IN OUT  EFI_DRIVER_BINDING_PROTOCOL  **SortedDriverBindingProtocols,
  IN      UINTN                        DriverBindingHandleCount,
  IN OUT  EFI_HANDLE                   *DriverBindingHandleBuffer,
  IN      BOOLEAN                      IsImageHandle
  )
{
  EFI_STATUS                   Status;
  EFI_DRIVER_BINDING_PROTOCOL  *DriverBinding;
  UINTN                        Index;
 
  //
  // Make sure the DriverBindingHandle is valid
  //
  CoreAcquireProtocolLock ();
 
  Status = CoreValidateHandle (DriverBindingHandle);
 
  CoreReleaseProtocolLock ();
 
  if (EFI_ERROR (Status)) {
    return;
  }
 
  //
  // If IsImageHandle is TRUE, then DriverBindingHandle is an image handle
  // Find all the DriverBindingHandles associated with that image handle and add them to the sorted list
  //
  if (IsImageHandle) {
    //
    // Loop through all the Driver Binding Handles
    //
    for (Index = 0; Index < DriverBindingHandleCount; Index++) {
      //
      // Retrieve the Driver Binding Protocol associated with each Driver Binding Handle
      //
      Status = CoreHandleProtocol (
                 DriverBindingHandleBuffer[Index],
                 &gEfiDriverBindingProtocolGuid,
                 (VOID **)&DriverBinding
                 );
      if (EFI_ERROR (Status) || (DriverBinding == NULL)) {
        continue;
      }
 
      //
      // If the ImageHandle associated with DriverBinding matches DriverBindingHandle,
      // then add the DriverBindingProtocol[Index] to the sorted list
      //
      if (DriverBinding->ImageHandle == DriverBindingHandle) {
        AddSortedDriverBindingProtocol (
          DriverBindingHandleBuffer[Index],
          NumberOfSortedDriverBindingProtocols,
          SortedDriverBindingProtocols,
          DriverBindingHandleCount,
          DriverBindingHandleBuffer,
          FALSE
          );
      }
    }
 
    return;
  }
 
  //
  // Retrieve the Driver Binding Protocol from DriverBindingHandle
  //
  Status = CoreHandleProtocol (
             DriverBindingHandle,
             &gEfiDriverBindingProtocolGuid,
             (VOID **)&DriverBinding
             );
  //
  // If DriverBindingHandle does not support the Driver Binding Protocol then return
  //
  if (EFI_ERROR (Status) || (DriverBinding == NULL)) {
    return;
  }
 
  //
  // See if DriverBinding is already in the sorted list
  //
  for (Index = 0; Index < *NumberOfSortedDriverBindingProtocols && Index < DriverBindingHandleCount; Index++) {
    if (DriverBinding == SortedDriverBindingProtocols[Index]) {
      return;
    }
  }
 
  //
  // Add DriverBinding to the end of the list
  //
  if (*NumberOfSortedDriverBindingProtocols < DriverBindingHandleCount) {
    SortedDriverBindingProtocols[*NumberOfSortedDriverBindingProtocols] = DriverBinding;
  }
 
  *NumberOfSortedDriverBindingProtocols = *NumberOfSortedDriverBindingProtocols + 1;
 
  //
  // Mark the cooresponding handle in DriverBindingHandleBuffer as used
  //
  for (Index = 0; Index < DriverBindingHandleCount; Index++) {
    if (DriverBindingHandleBuffer[Index] == DriverBindingHandle) {
      DriverBindingHandleBuffer[Index] = NULL;
    }
  }
}
 
EFI_STATUS
CoreConnectSingleController (
  IN  EFI_HANDLE                ControllerHandle,
  IN  EFI_HANDLE                *ContextDriverImageHandles OPTIONAL,
  IN  EFI_DEVICE_PATH_PROTOCOL  *RemainingDevicePath       OPTIONAL
  )
{
  EFI_STATUS                                 Status;
  UINTN                                      Index;
  EFI_HANDLE                                 DriverImageHandle;
  EFI_PLATFORM_DRIVER_OVERRIDE_PROTOCOL      *PlatformDriverOverride;
  EFI_BUS_SPECIFIC_DRIVER_OVERRIDE_PROTOCOL  *BusSpecificDriverOverride;
  UINTN                                      DriverBindingHandleCount;
  EFI_HANDLE                                 *DriverBindingHandleBuffer;
  UINTN                                      NewDriverBindingHandleCount;
  EFI_HANDLE                                 *NewDriverBindingHandleBuffer;
  EFI_DRIVER_BINDING_PROTOCOL                *DriverBinding;
  EFI_DRIVER_FAMILY_OVERRIDE_PROTOCOL        *DriverFamilyOverride;
  UINTN                                      NumberOfSortedDriverBindingProtocols;
  EFI_DRIVER_BINDING_PROTOCOL                **SortedDriverBindingProtocols;
  UINT32                                     DriverFamilyOverrideVersion;
  UINT32                                     HighestVersion;
  UINTN                                      HighestIndex;
  UINTN                                      SortIndex;
  BOOLEAN                                    OneStarted;
  BOOLEAN                                    DriverFound;
 
  //
  // Initialize local variables
  //
  DriverBindingHandleCount             = 0;
  DriverBindingHandleBuffer            = NULL;
  NumberOfSortedDriverBindingProtocols = 0;
  SortedDriverBindingProtocols         = NULL;
  PlatformDriverOverride               = NULL;
  NewDriverBindingHandleBuffer         = NULL;
 
  //
  // Get list of all Driver Binding Protocol Instances
  //
  Status = CoreLocateHandleBuffer (
             ByProtocol,
             &gEfiDriverBindingProtocolGuid,
             NULL,
             &DriverBindingHandleCount,
             &DriverBindingHandleBuffer
             );
  if (EFI_ERROR (Status) || (DriverBindingHandleCount == 0)) {
    return EFI_NOT_FOUND;
  }
 
  //
  // Allocate a duplicate array for the sorted Driver Binding Protocol Instances
  //
  SortedDriverBindingProtocols = AllocatePool (sizeof (VOID *) * DriverBindingHandleCount);
  if (SortedDriverBindingProtocols == NULL) {
    CoreFreePool (DriverBindingHandleBuffer);
    return EFI_OUT_OF_RESOURCES;
  }
 
  //
  // Add Driver Binding Protocols from Context Driver Image Handles first
  //
  if (ContextDriverImageHandles != NULL) {
    for (Index = 0; ContextDriverImageHandles[Index] != NULL; Index++) {
      AddSortedDriverBindingProtocol (
        ContextDriverImageHandles[Index],
        &NumberOfSortedDriverBindingProtocols,
        SortedDriverBindingProtocols,
        DriverBindingHandleCount,
        DriverBindingHandleBuffer,
        FALSE
        );
    }
  }
 
  //
  // Add the Platform Driver Override Protocol drivers for ControllerHandle next
  //
  Status = CoreLocateProtocol (
             &gEfiPlatformDriverOverrideProtocolGuid,
             NULL,
             (VOID **)&PlatformDriverOverride
             );
  if (!EFI_ERROR (Status) && (PlatformDriverOverride != NULL)) {
    DriverImageHandle = NULL;
    do {
      Status = PlatformDriverOverride->GetDriver (
                                         PlatformDriverOverride,
                                         ControllerHandle,
                                         &DriverImageHandle
                                         );
      if (!EFI_ERROR (Status)) {
        AddSortedDriverBindingProtocol (
          DriverImageHandle,
          &NumberOfSortedDriverBindingProtocols,
          SortedDriverBindingProtocols,
          DriverBindingHandleCount,
          DriverBindingHandleBuffer,
          TRUE
          );
      }
    } while (!EFI_ERROR (Status));
  }
 
  //
  // Add the Driver Family Override Protocol drivers for ControllerHandle
  //
  Status = CoreLocateProtocol (
             &gEfiDriverFamilyOverrideProtocolGuid,
             NULL,
             (VOID **)&DriverFamilyOverride
             );
  while (!EFI_ERROR (Status) && (DriverFamilyOverride != NULL)) {
    HighestIndex   = DriverBindingHandleCount;
    HighestVersion = 0;
    for (Index = 0; Index < DriverBindingHandleCount; Index++) {
      Status = CoreHandleProtocol (
                 DriverBindingHandleBuffer[Index],
                 &gEfiDriverFamilyOverrideProtocolGuid,
                 (VOID **)&DriverFamilyOverride
                 );
      if (!EFI_ERROR (Status) && (DriverFamilyOverride != NULL)) {
        DriverFamilyOverrideVersion = DriverFamilyOverride->GetVersion (DriverFamilyOverride);
        if ((HighestIndex == DriverBindingHandleCount) || (DriverFamilyOverrideVersion > HighestVersion)) {
          HighestVersion = DriverFamilyOverrideVersion;
          HighestIndex   = Index;
        }
      }
    }
 
    if (HighestIndex == DriverBindingHandleCount) {
      break;
    }
 
    AddSortedDriverBindingProtocol (
      DriverBindingHandleBuffer[HighestIndex],
      &NumberOfSortedDriverBindingProtocols,
      SortedDriverBindingProtocols,
      DriverBindingHandleCount,
      DriverBindingHandleBuffer,
      FALSE
      );
  }
 
  //
  // Get the Bus Specific Driver Override Protocol instance on the Controller Handle
  //
  Status = CoreHandleProtocol (
             ControllerHandle,
             &gEfiBusSpecificDriverOverrideProtocolGuid,
             (VOID **)&BusSpecificDriverOverride
             );
  if (!EFI_ERROR (Status) && (BusSpecificDriverOverride != NULL)) {
    DriverImageHandle = NULL;
    do {
      Status = BusSpecificDriverOverride->GetDriver (
                                            BusSpecificDriverOverride,
                                            &DriverImageHandle
                                            );
      if (!EFI_ERROR (Status)) {
        AddSortedDriverBindingProtocol (
          DriverImageHandle,
          &NumberOfSortedDriverBindingProtocols,
          SortedDriverBindingProtocols,
          DriverBindingHandleCount,
          DriverBindingHandleBuffer,
          TRUE
          );
      }
    } while (!EFI_ERROR (Status));
  }
 
  //
  // Then add all the remaining Driver Binding Protocols
  //
  SortIndex = NumberOfSortedDriverBindingProtocols;
  for (Index = 0; Index < DriverBindingHandleCount; Index++) {
    AddSortedDriverBindingProtocol (
      DriverBindingHandleBuffer[Index],
      &NumberOfSortedDriverBindingProtocols,
      SortedDriverBindingProtocols,
      DriverBindingHandleCount,
      DriverBindingHandleBuffer,
      FALSE
      );
  }
 
  //
  // Free the Driver Binding Handle Buffer
  //
  CoreFreePool (DriverBindingHandleBuffer);
 
  //
  // If the number of Driver Binding Protocols has increased since this function started, then return
  // EFI_NOT_READY, so it will be restarted
  //
  Status = CoreLocateHandleBuffer (
             ByProtocol,
             &gEfiDriverBindingProtocolGuid,
             NULL,
             &NewDriverBindingHandleCount,
             &NewDriverBindingHandleBuffer
             );
  CoreFreePool (NewDriverBindingHandleBuffer);
  if (NewDriverBindingHandleCount > DriverBindingHandleCount) {
    //
    // Free any buffers that were allocated with AllocatePool()
    //
    CoreFreePool (SortedDriverBindingProtocols);
 
    return EFI_NOT_READY;
  }
 
  //
  // Sort the remaining DriverBinding Protocol based on their Version field from
  // highest to lowest.
  //
  for ( ; SortIndex < NumberOfSortedDriverBindingProtocols; SortIndex++) {
    HighestVersion = SortedDriverBindingProtocols[SortIndex]->Version;
    HighestIndex   = SortIndex;
    for (Index = SortIndex + 1; Index < NumberOfSortedDriverBindingProtocols; Index++) {
      if (SortedDriverBindingProtocols[Index]->Version > HighestVersion) {
        HighestVersion = SortedDriverBindingProtocols[Index]->Version;
        HighestIndex   = Index;
      }
    }
 
    if (SortIndex != HighestIndex) {
      DriverBinding                              = SortedDriverBindingProtocols[SortIndex];
      SortedDriverBindingProtocols[SortIndex]    = SortedDriverBindingProtocols[HighestIndex];
      SortedDriverBindingProtocols[HighestIndex] = DriverBinding;
    }
  }
 
  //
  // Loop until no more drivers can be started on ControllerHandle
  //
  OneStarted = FALSE;
  do {
    //
    // Loop through the sorted Driver Binding Protocol Instances in order, and see if
    // any of the Driver Binding Protocols support the controller specified by
    // ControllerHandle.
    //
    DriverBinding = NULL;
    DriverFound   = FALSE;
    for (Index = 0; (Index < NumberOfSortedDriverBindingProtocols) && !DriverFound; Index++) {
      if (SortedDriverBindingProtocols[Index] != NULL) {
        DriverBinding = SortedDriverBindingProtocols[Index];
        PERF_DRIVER_BINDING_SUPPORT_BEGIN (DriverBinding->DriverBindingHandle, ControllerHandle);
        Status = DriverBinding->Supported (
                                  DriverBinding,
                                  ControllerHandle,
                                  RemainingDevicePath
                                  );
        PERF_DRIVER_BINDING_SUPPORT_END (DriverBinding->DriverBindingHandle, ControllerHandle);
        if (!EFI_ERROR (Status)) {
          SortedDriverBindingProtocols[Index] = NULL;
          DriverFound                         = TRUE;
 
          //
          // A driver was found that supports ControllerHandle, so attempt to start the driver
          // on ControllerHandle.
          //
          PERF_DRIVER_BINDING_START_BEGIN (DriverBinding->DriverBindingHandle, ControllerHandle);
          Status = DriverBinding->Start (
                                    DriverBinding,
                                    ControllerHandle,
                                    RemainingDevicePath
                                    );
          PERF_DRIVER_BINDING_START_END (DriverBinding->DriverBindingHandle, ControllerHandle);
 
          if (!EFI_ERROR (Status)) {
            //
            // The driver was successfully started on ControllerHandle, so set a flag
            //
            OneStarted = TRUE;
          }
        }
      }
    }
  } while (DriverFound);
 
  //
  // Free any buffers that were allocated with AllocatePool()
  //
  CoreFreePool (SortedDriverBindingProtocols);
 
  //
  // If at least one driver was started on ControllerHandle, then return EFI_SUCCESS.
  //
  if (OneStarted) {
    return EFI_SUCCESS;
  }
 
  //
  // If no drivers started and RemainingDevicePath is an End Device Path Node, then return EFI_SUCCESS
  //
  if (RemainingDevicePath != NULL) {
    if (IsDevicePathEnd (RemainingDevicePath)) {
      return EFI_SUCCESS;
    }
  }
 
  //
  // Otherwise, no drivers were started on ControllerHandle, so return EFI_NOT_FOUND
  //
  return EFI_NOT_FOUND;
}
 
EFI_STATUS
EFIAPI
CoreDisconnectController (
  IN  EFI_HANDLE  ControllerHandle,
  IN  EFI_HANDLE  DriverImageHandle  OPTIONAL,
  IN  EFI_HANDLE  ChildHandle        OPTIONAL
  )
{
  EFI_STATUS                   Status;
  IHANDLE                      *Handle;
  EFI_HANDLE                   *DriverImageHandleBuffer;
  EFI_HANDLE                   *ChildBuffer;
  UINTN                        Index;
  UINTN                        HandleIndex;
  UINTN                        DriverImageHandleCount;
  UINTN                        ChildrenToStop;
  UINTN                        ChildBufferCount;
  UINTN                        StopCount;
  BOOLEAN                      Duplicate;
  BOOLEAN                      ChildHandleValid;
  BOOLEAN                      DriverImageHandleValid;
  LIST_ENTRY                   *Link;
  LIST_ENTRY                   *ProtLink;
  OPEN_PROTOCOL_DATA           *OpenData;
  PROTOCOL_INTERFACE           *Prot;
  EFI_DRIVER_BINDING_PROTOCOL  *DriverBinding;
 
  //
  // Make sure ControllerHandle is valid
  //
  CoreAcquireProtocolLock ();
 
  Status = CoreValidateHandle (ControllerHandle);
  if (EFI_ERROR (Status)) {
    CoreReleaseProtocolLock ();
    return Status;
  }
 
  //
  // Make sure ChildHandle is valid if it is not NULL
  //
  if (ChildHandle != NULL) {
    Status = CoreValidateHandle (ChildHandle);
    if (EFI_ERROR (Status)) {
      CoreReleaseProtocolLock ();
      return Status;
    }
  }
 
  CoreReleaseProtocolLock ();
 
  Handle = ControllerHandle;
 
  //
  // Get list of drivers that are currently managing ControllerHandle
  //
  DriverImageHandleBuffer = NULL;
  DriverImageHandleCount  = 1;
 
  if (DriverImageHandle == NULL) {
    //
    // Look at each protocol interface for a match
    //
    DriverImageHandleCount = 0;
 
    CoreAcquireProtocolLock ();
    for (Link = Handle->Protocols.ForwardLink; Link != &Handle->Protocols; Link = Link->ForwardLink) {
      Prot = CR (Link, PROTOCOL_INTERFACE, Link, PROTOCOL_INTERFACE_SIGNATURE);
      for (ProtLink = Prot->OpenList.ForwardLink;
           ProtLink != &Prot->OpenList;
           ProtLink = ProtLink->ForwardLink)
      {
        OpenData = CR (ProtLink, OPEN_PROTOCOL_DATA, Link, OPEN_PROTOCOL_DATA_SIGNATURE);
        if ((OpenData->Attributes & EFI_OPEN_PROTOCOL_BY_DRIVER) != 0) {
          DriverImageHandleCount++;
        }
      }
    }
 
    CoreReleaseProtocolLock ();
 
    //
    // If there are no drivers managing this controller, then return EFI_SUCCESS
    //
    if (DriverImageHandleCount == 0) {
      Status = EFI_SUCCESS;
      goto Done;
    }
 
    DriverImageHandleBuffer = AllocatePool (sizeof (EFI_HANDLE) * DriverImageHandleCount);
    if (DriverImageHandleBuffer == NULL) {
      Status = EFI_OUT_OF_RESOURCES;
      goto Done;
    }
 
    DriverImageHandleCount = 0;
 
    CoreAcquireProtocolLock ();
    for (Link = Handle->Protocols.ForwardLink; Link != &Handle->Protocols; Link = Link->ForwardLink) {
      Prot = CR (Link, PROTOCOL_INTERFACE, Link, PROTOCOL_INTERFACE_SIGNATURE);
      for (ProtLink = Prot->OpenList.ForwardLink;
           ProtLink != &Prot->OpenList;
           ProtLink = ProtLink->ForwardLink)
      {
        OpenData = CR (ProtLink, OPEN_PROTOCOL_DATA, Link, OPEN_PROTOCOL_DATA_SIGNATURE);
        if ((OpenData->Attributes & EFI_OPEN_PROTOCOL_BY_DRIVER) != 0) {
          Duplicate = FALSE;
          for (Index = 0; Index < DriverImageHandleCount; Index++) {
            if (DriverImageHandleBuffer[Index] == OpenData->AgentHandle) {
              Duplicate = TRUE;
              break;
            }
          }
 
          if (!Duplicate) {
            DriverImageHandleBuffer[DriverImageHandleCount] = OpenData->AgentHandle;
            DriverImageHandleCount++;
          }
        }
      }
    }
 
    CoreReleaseProtocolLock ();
  }
 
  StopCount = 0;
  for (HandleIndex = 0; HandleIndex < DriverImageHandleCount; HandleIndex++) {
    if (DriverImageHandleBuffer != NULL) {
      DriverImageHandle = DriverImageHandleBuffer[HandleIndex];
    }
 
    //
    // Get the Driver Binding Protocol of the driver that is managing this controller
    //
    Status = CoreHandleProtocol (
               DriverImageHandle,
               &gEfiDriverBindingProtocolGuid,
               (VOID **)&DriverBinding
               );
    if (EFI_ERROR (Status) || (DriverBinding == NULL)) {
      Status = EFI_INVALID_PARAMETER;
      goto Done;
    }
 
    //
    // Look at each protocol interface for a match
    //
    DriverImageHandleValid = FALSE;
    ChildBufferCount       = 0;
 
    CoreAcquireProtocolLock ();
    for (Link = Handle->Protocols.ForwardLink; Link != &Handle->Protocols; Link = Link->ForwardLink) {
      Prot = CR (Link, PROTOCOL_INTERFACE, Link, PROTOCOL_INTERFACE_SIGNATURE);
      for (ProtLink = Prot->OpenList.ForwardLink;
           ProtLink != &Prot->OpenList;
           ProtLink = ProtLink->ForwardLink)
      {
        OpenData = CR (ProtLink, OPEN_PROTOCOL_DATA, Link, OPEN_PROTOCOL_DATA_SIGNATURE);
        if (OpenData->AgentHandle == DriverImageHandle) {
          if ((OpenData->Attributes & EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) != 0) {
            ChildBufferCount++;
          }
 
          if ((OpenData->Attributes & EFI_OPEN_PROTOCOL_BY_DRIVER) != 0) {
            DriverImageHandleValid = TRUE;
          }
        }
      }
    }
 
    CoreReleaseProtocolLock ();
 
    if (DriverImageHandleValid) {
      ChildHandleValid = FALSE;
      ChildBuffer      = NULL;
      if (ChildBufferCount != 0) {
        ChildBuffer = AllocatePool (sizeof (EFI_HANDLE) * ChildBufferCount);
        if (ChildBuffer == NULL) {
          Status = EFI_OUT_OF_RESOURCES;
          goto Done;
        }
 
        ChildBufferCount = 0;
 
        CoreAcquireProtocolLock ();
        for (Link = Handle->Protocols.ForwardLink; Link != &Handle->Protocols; Link = Link->ForwardLink) {
          Prot = CR (Link, PROTOCOL_INTERFACE, Link, PROTOCOL_INTERFACE_SIGNATURE);
          for (ProtLink = Prot->OpenList.ForwardLink;
               ProtLink != &Prot->OpenList;
               ProtLink = ProtLink->ForwardLink)
          {
            OpenData = CR (ProtLink, OPEN_PROTOCOL_DATA, Link, OPEN_PROTOCOL_DATA_SIGNATURE);
            if ((OpenData->AgentHandle == DriverImageHandle) &&
                ((OpenData->Attributes & EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) != 0))
            {
              Duplicate = FALSE;
              for (Index = 0; Index < ChildBufferCount; Index++) {
                if (ChildBuffer[Index] == OpenData->ControllerHandle) {
                  Duplicate = TRUE;
                  break;
                }
              }
 
              if (!Duplicate) {
                ChildBuffer[ChildBufferCount] = OpenData->ControllerHandle;
                if (ChildHandle == ChildBuffer[ChildBufferCount]) {
                  ChildHandleValid = TRUE;
                }
 
                ChildBufferCount++;
              }
            }
          }
        }
 
        CoreReleaseProtocolLock ();
      }
 
      if ((ChildHandle == NULL) || ChildHandleValid) {
        ChildrenToStop = 0;
        Status         = EFI_SUCCESS;
        if (ChildBufferCount > 0) {
          if (ChildHandle != NULL) {
            ChildrenToStop = 1;
            Status         = DriverBinding->Stop (DriverBinding, ControllerHandle, ChildrenToStop, &ChildHandle);
          } else {
            ChildrenToStop = ChildBufferCount;
            Status         = DriverBinding->Stop (DriverBinding, ControllerHandle, ChildrenToStop, ChildBuffer);
          }
        }
 
        if (!EFI_ERROR (Status) && ((ChildHandle == NULL) || (ChildBufferCount == ChildrenToStop))) {
          Status = DriverBinding->Stop (DriverBinding, ControllerHandle, 0, NULL);
        }
 
        if (!EFI_ERROR (Status)) {
          StopCount++;
        }
      }
 
      if (ChildBuffer != NULL) {
        CoreFreePool (ChildBuffer);
      }
    }
  }
 
  if (StopCount > 0) {
    Status = EFI_SUCCESS;
  } else {
    Status = EFI_NOT_FOUND;
  }
 
Done:
 
  if (DriverImageHandleBuffer != NULL) {
    CoreFreePool (DriverImageHandleBuffer);
  }
 
  return Status;
}