Exemplo n.º 1
0
Arquivo: Snp.c Projeto: MattDevo/edk2
/**
  Stop this driver on ControllerHandle. This service is called by the
  EFI boot service DisconnectController(). In order to
  make drivers as small as possible, there are a few calling
  restrictions for this service. DisconnectController()
  must follow these calling restrictions. If any other agent wishes
  to call Stop() it must also follow these calling restrictions.

  @param  This              Protocol instance pointer.
  @param  ControllerHandle  Handle of device to stop driver on
  @param  NumberOfChildren  Number of Handles in ChildHandleBuffer. If number of
                            children is zero stop the entire bus driver.
  @param  ChildHandleBuffer List of Child Handles to Stop.

  @retval EFI_SUCCESS       This driver is removed ControllerHandle
  @retval other             This driver was not removed from this device

**/
EFI_STATUS
EFIAPI
SimpleNetworkDriverStop (
  IN  EFI_DRIVER_BINDING_PROTOCOL    *This,
  IN  EFI_HANDLE                     Controller,
  IN  UINTN                          NumberOfChildren,
  IN  EFI_HANDLE                     *ChildHandleBuffer
  )
{
  EFI_STATUS                  Status;
  EFI_SIMPLE_NETWORK_PROTOCOL *SnpProtocol;
  SNP_DRIVER                  *Snp;
  EFI_PCI_IO_PROTOCOL         *PciIo;

  //
  // Get our context back.
  //
  Status = gBS->OpenProtocol (
                  Controller,
                  &gEfiSimpleNetworkProtocolGuid,
                  (VOID **) &SnpProtocol,
                  This->DriverBindingHandle,
                  Controller,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );

  if (EFI_ERROR (Status)) {
    return EFI_UNSUPPORTED;
  }

  Snp = EFI_SIMPLE_NETWORK_DEV_FROM_THIS (SnpProtocol);

  Status = gBS->UninstallProtocolInterface (
                  Controller,
                  &gEfiSimpleNetworkProtocolGuid,
                  &Snp->Snp
                  );

  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Close EXIT_BOOT_SERIVES Event
  //
  gBS->CloseEvent (Snp->ExitBootServicesEvent);

  Status = gBS->CloseProtocol (
                  Controller,
                  &gEfiNetworkInterfaceIdentifierProtocolGuid_31,
                  This->DriverBindingHandle,
                  Controller
                  );

  Status = gBS->CloseProtocol (
                  Controller,
                  &gEfiDevicePathProtocolGuid,
                  This->DriverBindingHandle,
                  Controller
                  );

  PxeShutdown (Snp);
  PxeStop (Snp);

  FreePool (Snp->RecycledTxBuf);

  PciIo = Snp->PciIo;
  PciIo->FreeBuffer (
           PciIo,
           SNP_MEM_PAGES (4096),
           Snp->Cpb
           );

  PciIo->FreeBuffer (
           PciIo,
           SNP_MEM_PAGES (sizeof (SNP_DRIVER)),
           Snp
           );

  return Status;
}
Exemplo n.º 2
0
Arquivo: Snp.c Projeto: M1cha/edk2
/**
  Start this driver on ControllerHandle. This service is called by the
  EFI boot service ConnectController(). In order to make
  drivers as small as possible, there are a few calling restrictions for
  this service. ConnectController() must follow these
  calling restrictions. If any other agent wishes to call Start() it
  must also follow these calling restrictions.

  @param  This                 Protocol instance pointer.
  @param  ControllerHandle     Handle of device to bind driver to.
  @param  RemainingDevicePath  Optional parameter use to pick a specific child
                               device to start.

  @retval EFI_SUCCESS          This driver is added to ControllerHandle
  @retval EFI_DEVICE_ERROR     This driver could not be started due to a device error
  @retval other                This driver does not support this device

**/
EFI_STATUS
EFIAPI
SimpleNetworkDriverStart (
  IN EFI_DRIVER_BINDING_PROTOCOL    *This,
  IN EFI_HANDLE                     Controller,
  IN EFI_DEVICE_PATH_PROTOCOL       *RemainingDevicePath
  )
{
  EFI_NETWORK_INTERFACE_IDENTIFIER_PROTOCOL *Nii;
  EFI_DEVICE_PATH_PROTOCOL                  *NiiDevicePath;
  EFI_STATUS                                Status;
  PXE_UNDI                                  *Pxe;
  SNP_DRIVER                                *Snp;
  VOID                                      *Address;
  EFI_HANDLE                                Handle;
  UINT8                                     BarIndex;
  PXE_STATFLAGS                             InitStatFlags;
  EFI_PCI_IO_PROTOCOL                       *PciIo;
  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR         *BarDesc;
  BOOLEAN                                   FoundIoBar;
  BOOLEAN                                   FoundMemoryBar;
  
  DEBUG ((EFI_D_NET, "\nSnpNotifyNetworkInterfaceIdentifier()  "));

  Status = gBS->OpenProtocol (
                  Controller,
                  &gEfiDevicePathProtocolGuid,
                  (VOID **) &NiiDevicePath,
                  This->DriverBindingHandle,
                  Controller,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );

  if (EFI_ERROR (Status)) {
    return Status;
  }

  Status = gBS->LocateDevicePath (
                  &gEfiPciIoProtocolGuid,
                  &NiiDevicePath,
                  &Handle
                  );

  if (EFI_ERROR (Status)) {
    return Status;
  }

  Status = gBS->OpenProtocol (
                  Handle,
                  &gEfiPciIoProtocolGuid,
                  (VOID **) &PciIo,
                  This->DriverBindingHandle,
                  Controller,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }
  //
  // Get the NII interface.
  //
  Status = gBS->OpenProtocol (
                  Controller,
                  &gEfiNetworkInterfaceIdentifierProtocolGuid_31,
                  (VOID **) &Nii,
                  This->DriverBindingHandle,
                  Controller,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );
  if (EFI_ERROR (Status)) {
    gBS->CloseProtocol (
          Controller,
          &gEfiDevicePathProtocolGuid,
          This->DriverBindingHandle,
          Controller
          );
    return Status;
  }

  DEBUG ((EFI_D_INFO, "Start(): UNDI3.1 found\n"));

  Pxe = (PXE_UNDI *) (UINTN) (Nii->Id);

  if (Calc8BitCksum (Pxe, Pxe->hw.Len) != 0) {
    DEBUG ((EFI_D_NET, "\n!PXE checksum is not correct.\n"));
    goto NiiError;
  }

  if ((Pxe->hw.Implementation & PXE_ROMID_IMP_PROMISCUOUS_RX_SUPPORTED) != 0) {
    //
    //  We can get any packets.
    //
  } else if ((Pxe->hw.Implementation & PXE_ROMID_IMP_BROADCAST_RX_SUPPORTED) != 0) {
    //
    //  We need to be able to get broadcast packets for DHCP.
    //  If we do not have promiscuous support, we must at least have
    //  broadcast support or we cannot do DHCP!
    //
  } else {
    DEBUG ((EFI_D_NET, "\nUNDI does not have promiscuous or broadcast support."));
    goto NiiError;
  }
  //
  // OK, we like this UNDI, and we know snp is not already there on this handle
  // Allocate and initialize a new simple network protocol structure.
  //
  Status = PciIo->AllocateBuffer (
                    PciIo,
                    AllocateAnyPages,
                    EfiBootServicesData,
                    SNP_MEM_PAGES (sizeof (SNP_DRIVER)),
                    &Address,
                    0
                    );

  if (Status != EFI_SUCCESS) {
    DEBUG ((EFI_D_NET, "\nCould not allocate SNP_DRIVER structure.\n"));
    goto NiiError;
  }

  Snp = (SNP_DRIVER *) (UINTN) Address;

  ZeroMem (Snp, sizeof (SNP_DRIVER));

  Snp->PciIo      = PciIo;
  Snp->Signature  = SNP_DRIVER_SIGNATURE;

  EfiInitializeLock (&Snp->Lock, TPL_NOTIFY);

  Snp->Snp.Revision       = EFI_SIMPLE_NETWORK_PROTOCOL_REVISION;
  Snp->Snp.Start          = SnpUndi32Start;
  Snp->Snp.Stop           = SnpUndi32Stop;
  Snp->Snp.Initialize     = SnpUndi32Initialize;
  Snp->Snp.Reset          = SnpUndi32Reset;
  Snp->Snp.Shutdown       = SnpUndi32Shutdown;
  Snp->Snp.ReceiveFilters = SnpUndi32ReceiveFilters;
  Snp->Snp.StationAddress = SnpUndi32StationAddress;
  Snp->Snp.Statistics     = SnpUndi32Statistics;
  Snp->Snp.MCastIpToMac   = SnpUndi32McastIpToMac;
  Snp->Snp.NvData         = SnpUndi32NvData;
  Snp->Snp.GetStatus      = SnpUndi32GetStatus;
  Snp->Snp.Transmit       = SnpUndi32Transmit;
  Snp->Snp.Receive        = SnpUndi32Receive;
  Snp->Snp.WaitForPacket  = NULL;

  Snp->Snp.Mode           = &Snp->Mode;

  Snp->TxRxBufferSize     = 0;
  Snp->TxRxBuffer         = NULL;

  Snp->RecycledTxBuf = AllocatePool (sizeof (UINT64) * SNP_TX_BUFFER_INCREASEMENT);
  if (Snp->RecycledTxBuf == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto Error_DeleteSNP;
  }
  Snp->MaxRecycledTxBuf    = SNP_TX_BUFFER_INCREASEMENT;
  Snp->RecycledTxBufCount  = 0;
 
  if (Nii->Revision >= EFI_NETWORK_INTERFACE_IDENTIFIER_PROTOCOL_REVISION) {
    Snp->IfNum = Nii->IfNum;

  } else {
    Snp->IfNum = (UINT8) (Nii->IfNum & 0xFF);
  }

  if ((Pxe->hw.Implementation & PXE_ROMID_IMP_HW_UNDI) != 0) {
    Snp->IsSwUndi             = FALSE;
    Snp->IssueUndi32Command   = &IssueHwUndiCommand;
  } else {
    Snp->IsSwUndi = TRUE;

    if ((Pxe->sw.Implementation & PXE_ROMID_IMP_SW_VIRT_ADDR) != 0) {
      Snp->IssueUndi32Command = (ISSUE_UNDI32_COMMAND) (UINTN) Pxe->sw.EntryPoint;
    } else {
      Snp->IssueUndi32Command = (ISSUE_UNDI32_COMMAND) (UINTN) ((UINT8) (UINTN) Pxe + Pxe->sw.EntryPoint);
    }
  }
  //
  // Allocate a global CPB and DB buffer for this UNDI interface.
  // we do this because:
  //
  // -UNDI 3.0 wants all the addresses passed to it (even the cpb and db) to be
  // within 2GB limit, create them here and map them so that when undi calls
  // v2p callback to check if the physical address is < 2gb, we will pass.
  //
  // -This is not a requirement for 3.1 or later UNDIs but the code looks
  // simpler if we use the same cpb, db variables for both old and new undi
  // interfaces from all the SNP interface calls (we don't map the buffers
  // for the newer undi interfaces though)
  // .
  // -it is OK to allocate one global set of CPB, DB pair for each UNDI
  // interface as EFI does not multi-task and so SNP will not be re-entered!
  //
  Status = PciIo->AllocateBuffer (
                    PciIo,
                    AllocateAnyPages,
                    EfiBootServicesData,
                    SNP_MEM_PAGES (4096),
                    &Address,
                    0
                    );

  if (Status != EFI_SUCCESS) {
    DEBUG ((EFI_D_NET, "\nCould not allocate CPB and DB structures.\n"));
    goto Error_DeleteSNP;
  }

  Snp->Cpb  = (VOID *) (UINTN) Address;
  Snp->Db   = (VOID *) ((UINTN) Address + 2048);

  //
  // Find the correct BAR to do IO.
  //
  // Enumerate through the PCI BARs for the device to determine which one is
  // the IO BAR.  Save the index of the BAR into the adapter info structure.
  // for regular 32bit BARs, 0 is memory mapped, 1 is io mapped
  //
  Snp->MemoryBarIndex = 0;
  Snp->IoBarIndex     = 1;
  FoundMemoryBar      = FALSE;
  FoundIoBar          = FALSE;
  for (BarIndex = 0; BarIndex < PCI_MAX_BAR; BarIndex++) {
    Status = PciIo->GetBarAttributes (
                      PciIo,
                      BarIndex,
                      NULL,
                      (VOID**) &BarDesc
                      );
    if (Status == EFI_UNSUPPORTED) {
      continue;
    } else if (EFI_ERROR (Status)) {
      goto Error_DeleteSNP;
    }

    if ((!FoundMemoryBar) && (BarDesc->ResType == ACPI_ADDRESS_SPACE_TYPE_MEM)) {
      Snp->MemoryBarIndex = BarIndex;
      FoundMemoryBar      = TRUE;
    } else if ((!FoundIoBar) && (BarDesc->ResType == ACPI_ADDRESS_SPACE_TYPE_IO)) {
      Snp->IoBarIndex = BarIndex;
      FoundIoBar      = TRUE;
    }

    FreePool (BarDesc);

    if (FoundMemoryBar && FoundIoBar) {
      break;
    }
  }

  Status = PxeStart (Snp);

  if (Status != EFI_SUCCESS) {
    goto Error_DeleteSNP;
  }

  Snp->Cdb.OpCode     = PXE_OPCODE_GET_INIT_INFO;
  Snp->Cdb.OpFlags    = PXE_OPFLAGS_NOT_USED;

  Snp->Cdb.CPBsize    = PXE_CPBSIZE_NOT_USED;
  Snp->Cdb.CPBaddr    = PXE_DBADDR_NOT_USED;

  Snp->Cdb.DBsize     = (UINT16) sizeof (Snp->InitInfo);
  Snp->Cdb.DBaddr     = (UINT64)(UINTN) (&Snp->InitInfo);

  Snp->Cdb.StatCode   = PXE_STATCODE_INITIALIZE;
  Snp->Cdb.StatFlags  = PXE_STATFLAGS_INITIALIZE;

  Snp->Cdb.IFnum      = Snp->IfNum;
  Snp->Cdb.Control    = PXE_CONTROL_LAST_CDB_IN_LIST;

  DEBUG ((EFI_D_NET, "\nSnp->undi.get_init_info()  "));

  (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);

  //
  // Save the INIT Stat Code...
  //
  InitStatFlags = Snp->Cdb.StatFlags;

  if (Snp->Cdb.StatCode != PXE_STATCODE_SUCCESS) {
    DEBUG ((EFI_D_NET, "\nSnp->undi.init_info()  %xh:%xh\n", Snp->Cdb.StatFlags, Snp->Cdb.StatCode));
    PxeStop (Snp);
    goto Error_DeleteSNP;
  }

  //
  //  Initialize simple network protocol mode structure
  //
  Snp->Mode.State               = EfiSimpleNetworkStopped;
  Snp->Mode.HwAddressSize       = Snp->InitInfo.HWaddrLen;
  Snp->Mode.MediaHeaderSize     = Snp->InitInfo.MediaHeaderLen;
  Snp->Mode.MaxPacketSize       = Snp->InitInfo.FrameDataLen;
  Snp->Mode.NvRamAccessSize     = Snp->InitInfo.NvWidth;
  Snp->Mode.NvRamSize           = Snp->InitInfo.NvCount * Snp->Mode.NvRamAccessSize;
  Snp->Mode.IfType              = Snp->InitInfo.IFtype;
  Snp->Mode.MaxMCastFilterCount = Snp->InitInfo.MCastFilterCnt;
  Snp->Mode.MCastFilterCount    = 0;

  switch (InitStatFlags & PXE_STATFLAGS_CABLE_DETECT_MASK) {
  case PXE_STATFLAGS_CABLE_DETECT_SUPPORTED:
    Snp->Mode.MediaPresentSupported = TRUE;
    break;

  case PXE_STATFLAGS_CABLE_DETECT_NOT_SUPPORTED:
  default:
    Snp->Mode.MediaPresentSupported = FALSE;
  }

  switch (InitStatFlags & PXE_STATFLAGS_GET_STATUS_NO_MEDIA_MASK) {
  case PXE_STATFLAGS_GET_STATUS_NO_MEDIA_SUPPORTED:
    Snp->MediaStatusSupported = TRUE;
    break;

  case PXE_STATFLAGS_GET_STATUS_NO_MEDIA_NOT_SUPPORTED:
  default:
    Snp->MediaStatusSupported = FALSE;
  }

  if ((Pxe->hw.Implementation & PXE_ROMID_IMP_STATION_ADDR_SETTABLE) != 0) {
    Snp->Mode.MacAddressChangeable = TRUE;
  } else {
    Snp->Mode.MacAddressChangeable = FALSE;
  }

  if ((Pxe->hw.Implementation & PXE_ROMID_IMP_MULTI_FRAME_SUPPORTED) != 0) {
    Snp->Mode.MultipleTxSupported = TRUE;
  } else {
    Snp->Mode.MultipleTxSupported = FALSE;
  }

  Snp->Mode.ReceiveFilterMask = EFI_SIMPLE_NETWORK_RECEIVE_UNICAST;

  if ((Pxe->hw.Implementation & PXE_ROMID_IMP_PROMISCUOUS_MULTICAST_RX_SUPPORTED) != 0) {
    Snp->Mode.ReceiveFilterMask |= EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS_MULTICAST;

  }

  if ((Pxe->hw.Implementation & PXE_ROMID_IMP_PROMISCUOUS_RX_SUPPORTED) != 0) {
    Snp->Mode.ReceiveFilterMask |= EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS;

  }

  if ((Pxe->hw.Implementation & PXE_ROMID_IMP_BROADCAST_RX_SUPPORTED) != 0) {
    Snp->Mode.ReceiveFilterMask |= EFI_SIMPLE_NETWORK_RECEIVE_BROADCAST;

  }

  if ((Pxe->hw.Implementation & PXE_ROMID_IMP_FILTERED_MULTICAST_RX_SUPPORTED) != 0) {
    Snp->Mode.ReceiveFilterMask |= EFI_SIMPLE_NETWORK_RECEIVE_MULTICAST;

  }

  if ((Pxe->hw.Implementation & PXE_ROMID_IMP_PROMISCUOUS_MULTICAST_RX_SUPPORTED) != 0) {
    Snp->Mode.ReceiveFilterMask |= EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS_MULTICAST;

  }

  Snp->Mode.ReceiveFilterSetting = 0;

  //
  //  need to get the station address to save in the mode structure. we need to
  // initialize the UNDI first for this.
  //
  Snp->TxRxBufferSize = Snp->InitInfo.MemoryRequired;
  Status              = PxeInit (Snp, PXE_OPFLAGS_INITIALIZE_DO_NOT_DETECT_CABLE);

  if (EFI_ERROR (Status)) {
    PxeStop (Snp);
    goto Error_DeleteSNP;
  }

  Status = PxeGetStnAddr (Snp);

  if (Status != EFI_SUCCESS) {
    DEBUG ((EFI_D_ERROR, "\nSnp->undi.get_station_addr() failed.\n"));
    PxeShutdown (Snp);
    PxeStop (Snp);
    goto Error_DeleteSNP;
  }

  Snp->Mode.MediaPresent = FALSE;

  //
  // We should not leave UNDI started and initialized here. this DriverStart()
  // routine must only find and attach the SNP interface to UNDI layer that it
  // finds on the given handle!
  // The UNDI layer will be started when upper layers call Snp->start.
  // How ever, this DriverStart() must fill up the snp mode structure which
  // contains the MAC address of the NIC. For this reason we started and
  // initialized UNDI here, now we are done, do a shutdown and stop of the
  // UNDI interface!
  //
  PxeShutdown (Snp);
  PxeStop (Snp);

  //
  // Create EXIT_BOOT_SERIVES Event
  //
  Status = gBS->CreateEventEx (
                  EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  SnpNotifyExitBootServices,
                  Snp,
                  &gEfiEventExitBootServicesGuid,
                  &Snp->ExitBootServicesEvent
                  );
  if (EFI_ERROR (Status)) {
    goto Error_DeleteSNP;
  }

  //
  //  add SNP to the undi handle
  //
  Status = gBS->InstallProtocolInterface (
                  &Controller,
                  &gEfiSimpleNetworkProtocolGuid,
                  EFI_NATIVE_INTERFACE,
                  &(Snp->Snp)
                  );

  if (!EFI_ERROR (Status)) {
    return Status;
  }

  PciIo->FreeBuffer (
           PciIo,
           SNP_MEM_PAGES (4096),
           Snp->Cpb
           );

Error_DeleteSNP:

  if (Snp->RecycledTxBuf != NULL) {
    FreePool (Snp->RecycledTxBuf);
  }

  PciIo->FreeBuffer (
           PciIo,
           SNP_MEM_PAGES (sizeof (SNP_DRIVER)),
           Snp
           );
NiiError:
  gBS->CloseProtocol (
        Controller,
        &gEfiNetworkInterfaceIdentifierProtocolGuid_31,
        This->DriverBindingHandle,
        Controller
        );

  gBS->CloseProtocol (
        Controller,
        &gEfiDevicePathProtocolGuid,
        This->DriverBindingHandle,
        Controller
        );

  //
  // If we got here that means we are in error state.
  //
  if (!EFI_ERROR (Status)) {
    Status = EFI_DEVICE_ERROR;
  }

  return Status;
}
Exemplo n.º 3
0
/**
  Allocate a block of memory to be used by the buffer pool.

  @param  Pool           The buffer pool to allocate memory for.
  @param  Pages          How many pages to allocate.

  @return The allocated memory block or NULL if failed.

**/
USBHC_MEM_BLOCK *
UsbHcAllocMemBlock (
  IN  USBHC_MEM_POOL      *Pool,
  IN  UINTN               Pages
  )
{
  USBHC_MEM_BLOCK         *Block;
  EFI_PCI_IO_PROTOCOL     *PciIo;
  VOID                    *BufHost;
  VOID                    *Mapping;
  EFI_PHYSICAL_ADDRESS    MappedAddr;
  UINTN                   Bytes;
  EFI_STATUS              Status;

  PciIo = Pool->PciIo;

  Block = AllocateZeroPool (sizeof (USBHC_MEM_BLOCK));
  if (Block == NULL) {
    return NULL;
  }

  //
  // each bit in the bit array represents USBHC_MEM_UNIT
  // bytes of memory in the memory block.
  //
  ASSERT (USBHC_MEM_UNIT * 8 <= EFI_PAGE_SIZE);

  Block->BufLen   = EFI_PAGES_TO_SIZE (Pages);
  Block->BitsLen  = Block->BufLen / (USBHC_MEM_UNIT * 8);
  Block->Bits     = AllocateZeroPool (Block->BitsLen);

  if (Block->Bits == NULL) {
    gBS->FreePool (Block);
    return NULL;
  }

  //
  // Allocate the number of Pages of memory, then map it for
  // bus master read and write.
  //
  Status = PciIo->AllocateBuffer (
                    PciIo,
                    AllocateAnyPages,
                    EfiBootServicesData,
                    Pages,
                    &BufHost,
                    0
                    );

  if (EFI_ERROR (Status)) {
    goto FREE_BITARRAY;
  }

  Bytes = EFI_PAGES_TO_SIZE (Pages);
  Status = PciIo->Map (
                    PciIo,
                    EfiPciIoOperationBusMasterCommonBuffer,
                    BufHost,
                    &Bytes,
                    &MappedAddr,
                    &Mapping
                    );

  if (EFI_ERROR (Status) || (Bytes != EFI_PAGES_TO_SIZE (Pages))) {
    goto FREE_BUFFER;
  }

  //
  // Check whether the data structure used by the host controller
  // should be restricted into the same 4G
  //
  if (Pool->Check4G && (Pool->Which4G != USB_HC_HIGH_32BIT (MappedAddr))) {
    PciIo->Unmap (PciIo, Mapping);
    goto FREE_BUFFER;
  }

  Block->BufHost  = BufHost;
  Block->Buf      = (UINT8 *) ((UINTN) MappedAddr);
  Block->Mapping  = Mapping;

  return Block;

FREE_BUFFER:
  PciIo->FreeBuffer (PciIo, Pages, BufHost);

FREE_BITARRAY:
  gBS->FreePool (Block->Bits);
  gBS->FreePool (Block);
  return NULL;
}