text: /** @file
    DXE PCI Segment Library instance layered on top of ESAL services.
  
    Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
    This program and the accompanying materials
    are licensed and made available under the terms and conditions of the BSD License
    which accompanies this distribution.  The full text of the license may be found at
    http://opensource.org/licenses/bsd-license.php.
  
    THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
    WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  
  **/
  
  #include <PiDxe.h>
  
  #include <Protocol/ExtendedSalServiceClasses.h>
  
  #include <Library/PciSegmentLib.h>
  #include <Library/BaseLib.h>
  #include <Library/DebugLib.h>
  #include <Library/ExtendedSalLib.h>
  
  /**
    Assert the validity of a PCI Segment address.
    A valid PCI Segment address should not contain 1's in bits 31:28
  
    @param  A The address to validate.
    @param  M Additional bits to assert to be zero.
  
  **/
  #define ASSERT_INVALID_PCI_SEGMENT_ADDRESS(A,M) \
    ASSERT (((A) & (0xf0000000 | (M))) == 0)
  
  /**
    Converts a PCI Library Address to a ESAL PCI Service Address.
    Based on SAL Spec 3.2, there are two SAL PCI Address:
  
    If address type = 0
    Bits 0..7 - Register address
    Bits 8..10 - Function number
    Bits 11..15 - Device number
    Bits 16..23 - Bus number
    Bits 24..31 - PCI segment group
    Bits 32..63 - Reserved (0)
  
    If address type = 1
    Bits 0..7 - Register address
    Bits 8..11 - Extended Register address
    Bits 12..14 - Function number
    Bits 15..19 - Device number
    Bits 20..27 - Bus number
    Bits 28..43 - PCI segment group
    Bits 44..63 - Reserved (0)
  
    @param  A The PCI Library Address to convert.
  
  **/
  #define CONVERT_PCI_SEGMENT_LIB_ADDRESS_TO_PCI_ESAL_ADDRESS0(Address)  (((Address >> 8) & 0xff000000) | (((Address) >> 4) & 0x00ffff00) | ((Address) & 0xff))
  #define CONVERT_PCI_SEGMENT_LIB_ADDRESS_TO_PCI_ESAL_ADDRESS1(Address)  (((Address >> 4) & 0xffff0000000) | ((Address) & 0xfffffff))
  
  /**
    Check a PCI Library Address is a PCI Compatible Address or not.
  **/
  #define IS_PCI_COMPATIBLE_ADDRESS(Address)  (((Address) & 0xf00) == 0)
  
  /**
    Internal worker function to read a PCI configuration register.
  
    This function wraps EsalPciConfigRead function of Extended SAL PCI
    Services Class.
    It reads and returns the PCI configuration register specified by Address,
    the width of data is specified by Width.
  
    @param  Address Address that encodes the PCI Bus, Device, Function and
                    Register.
    @param  Width   Width of data to read
  
    @return The value read from the PCI configuration register.
  
  **/
  UINT32
  DxePciSegmentLibEsalReadWorker (
    IN  UINT64        Address,
    IN  UINTN         Width
    )
  {
    SAL_RETURN_REGS Return;
  
    if (IS_PCI_COMPATIBLE_ADDRESS(Address)) {
      Return = EsalCall (
                 EFI_EXTENDED_SAL_PCI_SERVICES_PROTOCOL_GUID_LO,
                 EFI_EXTENDED_SAL_PCI_SERVICES_PROTOCOL_GUID_HI,
                 SalPciConfigReadFunctionId,
                 CONVERT_PCI_SEGMENT_LIB_ADDRESS_TO_PCI_ESAL_ADDRESS0 (Address),
                 Width,
                 EFI_SAL_PCI_COMPATIBLE_ADDRESS,
                 0,
                 0,
                 0,
                 0
                 );
    } else {
      Return = EsalCall (
                 EFI_EXTENDED_SAL_PCI_SERVICES_PROTOCOL_GUID_LO,
                 EFI_EXTENDED_SAL_PCI_SERVICES_PROTOCOL_GUID_HI,
                 SalPciConfigReadFunctionId,
                 CONVERT_PCI_SEGMENT_LIB_ADDRESS_TO_PCI_ESAL_ADDRESS1 (Address),
                 Width,
                 EFI_SAL_PCI_EXTENDED_REGISTER_ADDRESS,
                 0,
                 0,
                 0,
                 0
                 );
    }
  
    return (UINT32) Return.r9;
  }
  
  /**
    Internal worker function to writes a PCI configuration register.
  
    This function wraps EsalPciConfigWrite function of Extended SAL PCI
    Services Class.
    It writes the PCI configuration register specified by Address with the
    value specified by Data. The width of data is specifed by Width.
    Data is returned.
  
    @param  Address Address that encodes the PCI Bus, Device, Function and
                    Register.
    @param  Width   Width of data to write
    @param  Data    The value to write.
  
    @return The value written to the PCI configuration register.
  
  **/
  UINT32
  DxePciSegmentLibEsalWriteWorker (
    IN  UINT64           Address,
    IN  UINTN            Width,
    IN  UINT32           Data
    )
  {
    if (IS_PCI_COMPATIBLE_ADDRESS(Address)) {
      EsalCall (
        EFI_EXTENDED_SAL_PCI_SERVICES_PROTOCOL_GUID_LO,
        EFI_EXTENDED_SAL_PCI_SERVICES_PROTOCOL_GUID_HI,
        SalPciConfigWriteFunctionId,
        CONVERT_PCI_SEGMENT_LIB_ADDRESS_TO_PCI_ESAL_ADDRESS0 (Address),
        Width,
        Data,
        EFI_SAL_PCI_COMPATIBLE_ADDRESS,
        0,
        0,
        0
        );
    } else {
      EsalCall (
        EFI_EXTENDED_SAL_PCI_SERVICES_PROTOCOL_GUID_LO,
        EFI_EXTENDED_SAL_PCI_SERVICES_PROTOCOL_GUID_HI,
        SalPciConfigWriteFunctionId,
        CONVERT_PCI_SEGMENT_LIB_ADDRESS_TO_PCI_ESAL_ADDRESS1 (Address),
        Width,
        Data,
        EFI_SAL_PCI_EXTENDED_REGISTER_ADDRESS,
        0,
        0,
        0
        );
    }
  
    return Data;
  }
  
  /**
    Reads an 8-bit PCI configuration register.
  
    Reads and returns the 8-bit PCI configuration register specified by Address.
    This function must guarantee that all PCI read and write operations are
    serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
  
    @return The value read from the PCI configuration register.
  
  **/
  UINT8
  EFIAPI
  PciSegmentRead8 (
    IN      UINT64                    Address
    )
  {
    ASSERT_INVALID_PCI_SEGMENT_ADDRESS (Address, 0);
  
    return (UINT8) DxePciSegmentLibEsalReadWorker (Address, 1);
  }
  
  /**
    Writes an 8-bit PCI configuration register.
  
    Writes the 8-bit PCI configuration register specified by Address with the
    value specified by Value. Value is returned. This function must guarantee
    that all PCI read and write operations are serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
    @param  Data    The value to write.
  
    @return The value written to the PCI configuration register.
  
  **/
  UINT8
  EFIAPI
  PciSegmentWrite8 (
    IN      UINT64                    Address,
    IN      UINT8                     Data
    )
  {
    ASSERT_INVALID_PCI_SEGMENT_ADDRESS (Address, 0);
  
    return (UINT8) DxePciSegmentLibEsalWriteWorker (Address, 1, Data);
  }
  
  /**
    Performs a bitwise OR of an 8-bit PCI configuration register with
    an 8-bit value.
  
    Reads the 8-bit PCI configuration register specified by Address, performs a
    bitwise OR between the read result and the value specified by
    OrData, and writes the result to the 8-bit PCI configuration register
    specified by Address. The value written to the PCI configuration register is
    returned. This function must guarantee that all PCI read and write operations
    are serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
    @param  OrData  The value to OR with the PCI configuration register.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT8
  EFIAPI
  PciSegmentOr8 (
    IN      UINT64                    Address,
    IN      UINT8                     OrData
    )
  {
    return PciSegmentWrite8 (Address, (UINT8) (PciSegmentRead8 (Address) | OrData));
  }
  
  /**
    Performs a bitwise AND of an 8-bit PCI configuration register with an 8-bit
    value.
  
    Reads the 8-bit PCI configuration register specified by Address, performs a
    bitwise AND between the read result and the value specified by AndData, and
    writes the result to the 8-bit PCI configuration register specified by
    Address. The value written to the PCI configuration register is returned.
    This function must guarantee that all PCI read and write operations are
    serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
    @param  AndData The value to AND with the PCI configuration register.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT8
  EFIAPI
  PciSegmentAnd8 (
    IN      UINT64                    Address,
    IN      UINT8                     AndData
    )
  {
    return PciSegmentWrite8 (Address, (UINT8) (PciSegmentRead8 (Address) & AndData));
  }
  
  /**
    Performs a bitwise AND of an 8-bit PCI configuration register with an 8-bit
    value, followed a  bitwise OR with another 8-bit value.
  
    Reads the 8-bit PCI configuration register specified by Address, performs a
    bitwise AND between the read result and the value specified by AndData,
    performs a bitwise OR between the result of the AND operation and
    the value specified by OrData, and writes the result to the 8-bit PCI
    configuration register specified by Address. The value written to the PCI
    configuration register is returned. This function must guarantee that all PCI
    read and write operations are serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
    @param  AndData The value to AND with the PCI configuration register.
    @param  OrData  The value to OR with the result of the AND operation.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT8
  EFIAPI
  PciSegmentAndThenOr8 (
    IN      UINT64                    Address,
    IN      UINT8                     AndData,
    IN      UINT8                     OrData
    )
  {
    return PciSegmentWrite8 (Address, (UINT8) ((PciSegmentRead8 (Address) & AndData) | OrData));
  }
  
  /**
    Reads a bit field of a PCI configuration register.
  
    Reads the bit field in an 8-bit PCI configuration register. The bit field is
    specified by the StartBit and the EndBit. The value of the bit field is
    returned.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 7, then ASSERT().
    If EndBit is greater than 7, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
  
    @param  Address   PCI configuration register to read.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..7.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..7.
  
    @return The value of the bit field read from the PCI configuration register.
  
  **/
  UINT8
  EFIAPI
  PciSegmentBitFieldRead8 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit
    )
  {
    return BitFieldRead8 (PciSegmentRead8 (Address), StartBit, EndBit);
  }
  
  /**
    Writes a bit field to a PCI configuration register.
  
    Writes Value to the bit field of the PCI configuration register. The bit
    field is specified by the StartBit and the EndBit. All other bits in the
    destination PCI configuration register are preserved. The new value of the
    8-bit register is returned.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 7, then ASSERT().
    If EndBit is greater than 7, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
    If Value is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
  
    @param  Address   PCI configuration register to write.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..7.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..7.
    @param  Value     New value of the bit field.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT8
  EFIAPI
  PciSegmentBitFieldWrite8 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit,
    IN      UINT8                     Value
    )
  {
    return PciSegmentWrite8 (
             Address,
             BitFieldWrite8 (PciSegmentRead8 (Address), StartBit, EndBit, Value)
             );
  }
  
  /**
    Reads a bit field in an 8-bit PCI configuration, performs a bitwise OR, and
    writes the result back to the bit field in the 8-bit port.
  
    Reads the 8-bit PCI configuration register specified by Address, performs a
    bitwise OR between the read result and the value specified by
    OrData, and writes the result to the 8-bit PCI configuration register
    specified by Address. The value written to the PCI configuration register is
    returned. This function must guarantee that all PCI read and write operations
    are serialized. Extra left bits in OrData are stripped.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 7, then ASSERT().
    If EndBit is greater than 7, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
    If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
  
    @param  Address   PCI configuration register to write.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..7.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..7.
    @param  OrData    The value to OR with the PCI configuration register.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT8
  EFIAPI
  PciSegmentBitFieldOr8 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit,
    IN      UINT8                     OrData
    )
  {
    return PciSegmentWrite8 (
             Address,
             BitFieldOr8 (PciSegmentRead8 (Address), StartBit, EndBit, OrData)
             );
  }
  
  /**
    Reads a bit field in an 8-bit PCI configuration register, performs a bitwise
    AND, and writes the result back to the bit field in the 8-bit register.
  
    Reads the 8-bit PCI configuration register specified by Address, performs a
    bitwise AND between the read result and the value specified by AndData, and
    writes the result to the 8-bit PCI configuration register specified by
    Address. The value written to the PCI configuration register is returned.
    This function must guarantee that all PCI read and write operations are
    serialized. Extra left bits in AndData are stripped.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 7, then ASSERT().
    If EndBit is greater than 7, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
    If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
  
    @param  Address   PCI configuration register to write.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..7.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..7.
    @param  AndData   The value to AND with the PCI configuration register.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT8
  EFIAPI
  PciSegmentBitFieldAnd8 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit,
    IN      UINT8                     AndData
    )
  {
    return PciSegmentWrite8 (
             Address,
             BitFieldAnd8 (PciSegmentRead8 (Address), StartBit, EndBit, AndData)
             );
  }
  
  /**
    Reads a bit field in an 8-bit port, performs a bitwise AND followed by a
    bitwise OR, and writes the result back to the bit field in the
    8-bit port.
  
    Reads the 8-bit PCI configuration register specified by Address, performs a
    bitwise AND followed by a bitwise OR between the read result and
    the value specified by AndData, and writes the result to the 8-bit PCI
    configuration register specified by Address. The value written to the PCI
    configuration register is returned. This function must guarantee that all PCI
    read and write operations are serialized. Extra left bits in both AndData and
    OrData are stripped.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 7, then ASSERT().
    If EndBit is greater than 7, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
    If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
    If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
  
    @param  Address   PCI configuration register to write.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..7.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..7.
    @param  AndData   The value to AND with the PCI configuration register.
    @param  OrData    The value to OR with the result of the AND operation.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT8
  EFIAPI
  PciSegmentBitFieldAndThenOr8 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit,
    IN      UINT8                     AndData,
    IN      UINT8                     OrData
    )
  {
    return PciSegmentWrite8 (
             Address,
             BitFieldAndThenOr8 (PciSegmentRead8 (Address), StartBit, EndBit, AndData, OrData)
             );
  }
  
  /**
    Reads a 16-bit PCI configuration register.
  
    Reads and returns the 16-bit PCI configuration register specified by Address.
    This function must guarantee that all PCI read and write operations are
    serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
  
    @return The value read from the PCI configuration register.
  
  **/
  UINT16
  EFIAPI
  PciSegmentRead16 (
    IN      UINT64                    Address
    )
  {
    ASSERT_INVALID_PCI_SEGMENT_ADDRESS (Address, 1);
  
    return (UINT16) DxePciSegmentLibEsalReadWorker (Address, 2);
  }
  
  /**
    Writes a 16-bit PCI configuration register.
  
    Writes the 16-bit PCI configuration register specified by Address with the
    value specified by Value. Value is returned. This function must guarantee
    that all PCI read and write operations are serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
    @param  Data    The value to write.
  
    @return The value written to the PCI configuration register.
  
  **/
  UINT16
  EFIAPI
  PciSegmentWrite16 (
    IN      UINT64                    Address,
    IN      UINT16                    Data
    )
  {
    ASSERT_INVALID_PCI_SEGMENT_ADDRESS (Address, 1);
  
    return (UINT16) DxePciSegmentLibEsalWriteWorker (Address, 2, Data);
  }
  
  /**
    Performs a bitwise OR of a 16-bit PCI configuration register with
    a 16-bit value.
  
    Reads the 16-bit PCI configuration register specified by Address, performs a
    bitwise OR between the read result and the value specified by
    OrData, and writes the result to the 16-bit PCI configuration register
    specified by Address. The value written to the PCI configuration register is
    returned. This function must guarantee that all PCI read and write operations
    are serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
    @param  OrData  The value to OR with the PCI configuration register.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT16
  EFIAPI
  PciSegmentOr16 (
    IN      UINT64                    Address,
    IN      UINT16                    OrData
    )
  {
    return PciSegmentWrite16 (Address, (UINT16) (PciSegmentRead16 (Address) | OrData));
  }
  
  /**
    Performs a bitwise AND of a 16-bit PCI configuration register with a 16-bit
    value.
  
    Reads the 16-bit PCI configuration register specified by Address, performs a
    bitwise AND between the read result and the value specified by AndData, and
    writes the result to the 16-bit PCI configuration register specified by
    Address. The value written to the PCI configuration register is returned.
    This function must guarantee that all PCI read and write operations are
    serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
    @param  AndData The value to AND with the PCI configuration register.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT16
  EFIAPI
  PciSegmentAnd16 (
    IN      UINT64                    Address,
    IN      UINT16                    AndData
    )
  {
    return PciSegmentWrite16 (Address, (UINT16) (PciSegmentRead16 (Address) & AndData));
  }
  
  /**
    Performs a bitwise AND of a 16-bit PCI configuration register with a 16-bit
    value, followed a  bitwise OR with another 16-bit value.
  
    Reads the 16-bit PCI configuration register specified by Address, performs a
    bitwise AND between the read result and the value specified by AndData,
    performs a bitwise OR between the result of the AND operation and
    the value specified by OrData, and writes the result to the 16-bit PCI
    configuration register specified by Address. The value written to the PCI
    configuration register is returned. This function must guarantee that all PCI
    read and write operations are serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
    @param  AndData The value to AND with the PCI configuration register.
    @param  OrData  The value to OR with the result of the AND operation.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT16
  EFIAPI
  PciSegmentAndThenOr16 (
    IN      UINT64                    Address,
    IN      UINT16                    AndData,
    IN      UINT16                    OrData
    )
  {
    return PciSegmentWrite16 (Address, (UINT16) ((PciSegmentRead16 (Address) & AndData) | OrData));
  }
  
  /**
    Reads a bit field of a PCI configuration register.
  
    Reads the bit field in a 16-bit PCI configuration register. The bit field is
    specified by the StartBit and the EndBit. The value of the bit field is
    returned.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 15, then ASSERT().
    If EndBit is greater than 15, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
  
    @param  Address   PCI configuration register to read.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..15.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..15.
  
    @return The value of the bit field read from the PCI configuration register.
  
  **/
  UINT16
  EFIAPI
  PciSegmentBitFieldRead16 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit
    )
  {
    return BitFieldRead16 (PciSegmentRead16 (Address), StartBit, EndBit);
  }
  
  /**
    Writes a bit field to a PCI configuration register.
  
    Writes Value to the bit field of the PCI configuration register. The bit
    field is specified by the StartBit and the EndBit. All other bits in the
    destination PCI configuration register are preserved. The new value of the
    16-bit register is returned.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 15, then ASSERT().
    If EndBit is greater than 15, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
    If Value is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
  
    @param  Address   PCI configuration register to write.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..15.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..15.
    @param  Value     New value of the bit field.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT16
  EFIAPI
  PciSegmentBitFieldWrite16 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit,
    IN      UINT16                    Value
    )
  {
    return PciSegmentWrite16 (
             Address,
             BitFieldWrite16 (PciSegmentRead16 (Address), StartBit, EndBit, Value)
             );
  }
  
  /**
    Reads a bit field in a 16-bit PCI configuration, performs a bitwise OR, and
    writes the result back to the bit field in the 16-bit port.
  
    Reads the 16-bit PCI configuration register specified by Address, performs a
    bitwise OR between the read result and the value specified by
    OrData, and writes the result to the 16-bit PCI configuration register
    specified by Address. The value written to the PCI configuration register is
    returned. This function must guarantee that all PCI read and write operations
    are serialized. Extra left bits in OrData are stripped.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 15, then ASSERT().
    If EndBit is greater than 15, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
    If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
  
    @param  Address   PCI configuration register to write.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..15.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..15.
    @param  OrData    The value to OR with the PCI configuration register.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT16
  EFIAPI
  PciSegmentBitFieldOr16 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit,
    IN      UINT16                    OrData
    )
  {
    return PciSegmentWrite16 (
             Address,
             BitFieldOr16 (PciSegmentRead16 (Address), StartBit, EndBit, OrData)
             );
  }
  
  /**
    Reads a bit field in a 16-bit PCI configuration register, performs a bitwise
    AND, and writes the result back to the bit field in the 16-bit register.
  
    Reads the 16-bit PCI configuration register specified by Address, performs a
    bitwise AND between the read result and the value specified by AndData, and
    writes the result to the 16-bit PCI configuration register specified by
    Address. The value written to the PCI configuration register is returned.
    This function must guarantee that all PCI read and write operations are
    serialized. Extra left bits in AndData are stripped.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 15, then ASSERT().
    If EndBit is greater than 15, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
    If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
  
    @param  Address   PCI configuration register to write.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..15.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..15.
    @param  AndData   The value to AND with the PCI configuration register.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT16
  EFIAPI
  PciSegmentBitFieldAnd16 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit,
    IN      UINT16                    AndData
    )
  {
    return PciSegmentWrite16 (
             Address,
             BitFieldAnd16 (PciSegmentRead16 (Address), StartBit, EndBit, AndData)
             );
  }
  
  /**
    Reads a bit field in a 16-bit port, performs a bitwise AND followed by a
    bitwise OR, and writes the result back to the bit field in the
    16-bit port.
  
    Reads the 16-bit PCI configuration register specified by Address, performs a
    bitwise AND followed by a bitwise OR between the read result and
    the value specified by AndData, and writes the result to the 16-bit PCI
    configuration register specified by Address. The value written to the PCI
    configuration register is returned. This function must guarantee that all PCI
    read and write operations are serialized. Extra left bits in both AndData and
    OrData are stripped.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 15, then ASSERT().
    If EndBit is greater than 15, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
    If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
    If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
  
    @param  Address   PCI configuration register to write.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..15.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..15.
    @param  AndData   The value to AND with the PCI configuration register.
    @param  OrData    The value to OR with the result of the AND operation.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT16
  EFIAPI
  PciSegmentBitFieldAndThenOr16 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit,
    IN      UINT16                    AndData,
    IN      UINT16                    OrData
    )
  {
    return PciSegmentWrite16 (
             Address,
             BitFieldAndThenOr16 (PciSegmentRead16 (Address), StartBit, EndBit, AndData, OrData)
             );
  }
  
  /**
    Reads a 32-bit PCI configuration register.
  
    Reads and returns the 32-bit PCI configuration register specified by Address.
    This function must guarantee that all PCI read and write operations are
    serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
  
    @return The value read from the PCI configuration register.
  
  **/
  UINT32
  EFIAPI
  PciSegmentRead32 (
    IN      UINT64                    Address
    )
  {
    ASSERT_INVALID_PCI_SEGMENT_ADDRESS (Address, 3);
  
    return DxePciSegmentLibEsalReadWorker (Address, 4);
  }
  
  /**
    Writes a 32-bit PCI configuration register.
  
    Writes the 32-bit PCI configuration register specified by Address with the
    value specified by Value. Value is returned. This function must guarantee
    that all PCI read and write operations are serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
    @param  Data    The value to write.
  
    @return The value written to the PCI configuration register.
  
  **/
  UINT32
  EFIAPI
  PciSegmentWrite32 (
    IN      UINT64                    Address,
    IN      UINT32                    Data
    )
  {
    ASSERT_INVALID_PCI_SEGMENT_ADDRESS (Address, 3);
  
    return DxePciSegmentLibEsalWriteWorker (Address, 4, Data);
  }
  
  /**
    Performs a bitwise OR of a 32-bit PCI configuration register with
    a 32-bit value.
  
    Reads the 32-bit PCI configuration register specified by Address, performs a
    bitwise OR between the read result and the value specified by
    OrData, and writes the result to the 32-bit PCI configuration register
    specified by Address. The value written to the PCI configuration register is
    returned. This function must guarantee that all PCI read and write operations
    are serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
    @param  OrData  The value to OR with the PCI configuration register.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT32
  EFIAPI
  PciSegmentOr32 (
    IN      UINT64                    Address,
    IN      UINT32                    OrData
    )
  {
    return PciSegmentWrite32 (Address, PciSegmentRead32 (Address) | OrData);
  }
  
  /**
    Performs a bitwise AND of a 32-bit PCI configuration register with a 32-bit
    value.
  
    Reads the 32-bit PCI configuration register specified by Address, performs a
    bitwise AND between the read result and the value specified by AndData, and
    writes the result to the 32-bit PCI configuration register specified by
    Address. The value written to the PCI configuration register is returned.
    This function must guarantee that all PCI read and write operations are
    serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
    @param  AndData The value to AND with the PCI configuration register.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT32
  EFIAPI
  PciSegmentAnd32 (
    IN      UINT64                    Address,
    IN      UINT32                    AndData
    )
  {
    return PciSegmentWrite32 (Address, PciSegmentRead32 (Address) & AndData);
  }
  
  /**
    Performs a bitwise AND of a 32-bit PCI configuration register with a 32-bit
    value, followed a  bitwise OR with another 32-bit value.
  
    Reads the 32-bit PCI configuration register specified by Address, performs a
    bitwise AND between the read result and the value specified by AndData,
    performs a bitwise OR between the result of the AND operation and
    the value specified by OrData, and writes the result to the 32-bit PCI
    configuration register specified by Address. The value written to the PCI
    configuration register is returned. This function must guarantee that all PCI
    read and write operations are serialized.
  
    If any reserved bits in Address are set, then ASSERT().
  
    @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
                    Register.
    @param  AndData The value to AND with the PCI configuration register.
    @param  OrData  The value to OR with the result of the AND operation.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT32
  EFIAPI
  PciSegmentAndThenOr32 (
    IN      UINT64                    Address,
    IN      UINT32                    AndData,
    IN      UINT32                    OrData
    )
  {
    return PciSegmentWrite32 (Address, (PciSegmentRead32 (Address) & AndData) | OrData);
  }
  
  /**
    Reads a bit field of a PCI configuration register.
  
    Reads the bit field in a 32-bit PCI configuration register. The bit field is
    specified by the StartBit and the EndBit. The value of the bit field is
    returned.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 31, then ASSERT().
    If EndBit is greater than 31, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
  
    @param  Address   PCI configuration register to read.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..31.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..31.
  
    @return The value of the bit field read from the PCI configuration register.
  
  **/
  UINT32
  EFIAPI
  PciSegmentBitFieldRead32 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit
    )
  {
    return BitFieldRead32 (PciSegmentRead32 (Address), StartBit, EndBit);
  }
  
  /**
    Writes a bit field to a PCI configuration register.
  
    Writes Value to the bit field of the PCI configuration register. The bit
    field is specified by the StartBit and the EndBit. All other bits in the
    destination PCI configuration register are preserved. The new value of the
    32-bit register is returned.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 31, then ASSERT().
    If EndBit is greater than 31, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
    If Value is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
  
    @param  Address   PCI configuration register to write.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..31.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..31.
    @param  Value     New value of the bit field.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT32
  EFIAPI
  PciSegmentBitFieldWrite32 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit,
    IN      UINT32                    Value
    )
  {
    return PciSegmentWrite32 (
             Address,
             BitFieldWrite32 (PciSegmentRead32 (Address), StartBit, EndBit, Value)
             );
  }
  
  /**
    Reads a bit field in a 32-bit PCI configuration, performs a bitwise OR, and
    writes the result back to the bit field in the 32-bit port.
  
    Reads the 32-bit PCI configuration register specified by Address, performs a
    bitwise OR between the read result and the value specified by
    OrData, and writes the result to the 32-bit PCI configuration register
    specified by Address. The value written to the PCI configuration register is
    returned. This function must guarantee that all PCI read and write operations
    are serialized. Extra left bits in OrData are stripped.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 31, then ASSERT().
    If EndBit is greater than 31, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
    If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
  
    @param  Address   PCI configuration register to write.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..31.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..31.
    @param  OrData    The value to OR with the PCI configuration register.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT32
  EFIAPI
  PciSegmentBitFieldOr32 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit,
    IN      UINT32                    OrData
    )
  {
    return PciSegmentWrite32 (
             Address,
             BitFieldOr32 (PciSegmentRead32 (Address), StartBit, EndBit, OrData)
             );
  }
  
  /**
    Reads a bit field in a 32-bit PCI configuration register, performs a bitwise
    AND, and writes the result back to the bit field in the 32-bit register.
  
    Reads the 32-bit PCI configuration register specified by Address, performs a
    bitwise AND between the read result and the value specified by AndData, and
    writes the result to the 32-bit PCI configuration register specified by
    Address. The value written to the PCI configuration register is returned.
    This function must guarantee that all PCI read and write operations are
    serialized. Extra left bits in AndData are stripped.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 31, then ASSERT().
    If EndBit is greater than 31, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
    If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
  
    @param  Address   PCI configuration register to write.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..31.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..31.
    @param  AndData   The value to AND with the PCI configuration register.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT32
  EFIAPI
  PciSegmentBitFieldAnd32 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit,
    IN      UINT32                    AndData
    )
  {
    return PciSegmentWrite32 (
             Address,
             BitFieldAnd32 (PciSegmentRead32 (Address), StartBit, EndBit, AndData)
             );
  }
  
  /**
    Reads a bit field in a 32-bit port, performs a bitwise AND followed by a
    bitwise OR, and writes the result back to the bit field in the
    32-bit port.
  
    Reads the 32-bit PCI configuration register specified by Address, performs a
    bitwise AND followed by a bitwise OR between the read result and
    the value specified by AndData, and writes the result to the 32-bit PCI
    configuration register specified by Address. The value written to the PCI
    configuration register is returned. This function must guarantee that all PCI
    read and write operations are serialized. Extra left bits in both AndData and
    OrData are stripped.
  
    If any reserved bits in Address are set, then ASSERT().
    If StartBit is greater than 31, then ASSERT().
    If EndBit is greater than 31, then ASSERT().
    If EndBit is less than StartBit, then ASSERT().
    If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
    If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
  
    @param  Address   PCI configuration register to write.
    @param  StartBit  The ordinal of the least significant bit in the bit field.
                      Range 0..31.
    @param  EndBit    The ordinal of the most significant bit in the bit field.
                      Range 0..31.
    @param  AndData   The value to AND with the PCI configuration register.
    @param  OrData    The value to OR with the result of the AND operation.
  
    @return The value written back to the PCI configuration register.
  
  **/
  UINT32
  EFIAPI
  PciSegmentBitFieldAndThenOr32 (
    IN      UINT64                    Address,
    IN      UINTN                     StartBit,
    IN      UINTN                     EndBit,
    IN      UINT32                    AndData,
    IN      UINT32                    OrData
    )
  {
    return PciSegmentWrite32 (
             Address,
             BitFieldAndThenOr32 (PciSegmentRead32 (Address), StartBit, EndBit, AndData, OrData)
             );
  }
  
  /**
    Reads a range of PCI configuration registers into a caller supplied buffer.
  
    Reads the range of PCI configuration registers specified by StartAddress and
    Size into the buffer specified by Buffer. This function only allows the PCI
    configuration registers from a single PCI function to be read. Size is
    returned. When possible 32-bit PCI configuration read cycles are used to read
    from StartAdress to StartAddress + Size. Due to alignment restrictions, 8-bit
    and 16-bit PCI configuration read cycles may be used at the beginning and the
    end of the range.
  
    If StartAddress > 0x0FFFFFFF, then ASSERT().
    If ((StartAddress & 0xFFF) + Size) > 0x1000, then ASSERT().
    If Size > 0 and Buffer is NULL, then ASSERT().
  
    @param  StartAddress  Starting Address that encodes the PCI Segment, Bus, Device,
                          Function and Register.
    @param  Size          Size in bytes of the transfer.
    @param  Buffer        Pointer to a buffer receiving the data read.
  
    @return Size
  
  **/
  UINTN
  EFIAPI
  PciSegmentReadBuffer (
    IN      UINT64                    StartAddress,
    IN      UINTN                     Size,
    OUT     VOID                      *Buffer
    )
  {
    UINTN                             ReturnValue;
  
    ASSERT_INVALID_PCI_SEGMENT_ADDRESS (StartAddress, 0);
    ASSERT (((StartAddress & 0xFFF) + Size) <= 0x1000);
  
    if (Size == 0) {
      return Size;
    }
  
    ASSERT (Buffer != NULL);
  
    //
    // Save Size for return
    //
    ReturnValue = Size;
  
    if ((StartAddress & 1) != 0) {
      //
      // Read a byte if StartAddress is byte aligned
      //
      *(volatile UINT8 *)Buffer = PciSegmentRead8 (StartAddress);
      StartAddress += sizeof (UINT8);
      Size -= sizeof (UINT8);
      Buffer = (UINT8*)Buffer + 1;
    }
  
    if (Size >= sizeof (UINT16) && (StartAddress & 2) != 0) {
      //
      // Read a word if StartAddress is word aligned
      //
      *(volatile UINT16 *)Buffer = PciSegmentRead16 (StartAddress);
      StartAddress += sizeof (UINT16);
      Size -= sizeof (UINT16);
      Buffer = (UINT16*)Buffer + 1;
    }
  
    while (Size >= sizeof (UINT32)) {
      //
      // Read as many double words as possible
      //
      *(volatile UINT32 *)Buffer = PciSegmentRead32 (StartAddress);
      StartAddress += sizeof (UINT32);
      Size -= sizeof (UINT32);
      Buffer = (UINT32*)Buffer + 1;
    }
  
    if (Size >= sizeof (UINT16)) {
      //
      // Read the last remaining word if exist
      //
      *(volatile UINT16 *)Buffer = PciSegmentRead16 (StartAddress);
      StartAddress += sizeof (UINT16);
      Size -= sizeof (UINT16);
      Buffer = (UINT16*)Buffer + 1;
    }
  
    if (Size >= sizeof (UINT8)) {
      //
      // Read the last remaining byte if exist
      //
      *(volatile UINT8 *)Buffer = PciSegmentRead8 (StartAddress);
    }
  
    return ReturnValue;
  }
  
  /**
    Copies the data in a caller supplied buffer to a specified range of PCI
    configuration space.
  
    Writes the range of PCI configuration registers specified by StartAddress and
    Size from the buffer specified by Buffer. This function only allows the PCI
    configuration registers from a single PCI function to be written. Size is
    returned. When possible 32-bit PCI configuration write cycles are used to
    write from StartAdress to StartAddress + Size. Due to alignment restrictions,
    8-bit and 16-bit PCI configuration write cycles may be used at the beginning
    and the end of the range.
  
    If StartAddress > 0x0FFFFFFF, then ASSERT().
    If ((StartAddress & 0xFFF) + Size) > 0x1000, then ASSERT().
    If Size > 0 and Buffer is NULL, then ASSERT().
  
    @param  StartAddress  Starting Address that encodes the PCI Segment, Bus, Device,
                          Function and Register.
    @param  Size          Size in bytes of the transfer.
    @param  Buffer        Pointer to a buffer containing the data to write.
  
    @return Size
  
  **/
  UINTN
  EFIAPI
  PciSegmentWriteBuffer (
    IN      UINT64                    StartAddress,
    IN      UINTN                     Size,
    IN      VOID                      *Buffer
    )
  {
    UINTN                             ReturnValue;
  
    ASSERT_INVALID_PCI_SEGMENT_ADDRESS (StartAddress, 0);
    ASSERT (((StartAddress & 0xFFF) + Size) <= 0x1000);
  
    if (Size == 0) {
      return 0;
    }
  
    ASSERT (Buffer != NULL);
  
    //
    // Save Size for return
    //
    ReturnValue = Size;
  
    if ((StartAddress & 1) != 0) {
      //
      // Write a byte if StartAddress is byte aligned
      //
      PciSegmentWrite8 (StartAddress, *(UINT8*)Buffer);
      StartAddress += sizeof (UINT8);
      Size -= sizeof (UINT8);
      Buffer = (UINT8*)Buffer + 1;
    }
  
    if (Size >= sizeof (UINT16) && (StartAddress & 2) != 0) {
      //
      // Write a word if StartAddress is word aligned
      //
      PciSegmentWrite16 (StartAddress, *(UINT16*)Buffer);
      StartAddress += sizeof (UINT16);
      Size -= sizeof (UINT16);
      Buffer = (UINT16*)Buffer + 1;
    }
  
    while (Size >= sizeof (UINT32)) {
      //
      // Write as many double words as possible
      //
      PciSegmentWrite32 (StartAddress, *(UINT32*)Buffer);
      StartAddress += sizeof (UINT32);
      Size -= sizeof (UINT32);
      Buffer = (UINT32*)Buffer + 1;
    }
  
    if (Size >= sizeof (UINT16)) {
      //
      // Write the last remaining word if exist
      //
      PciSegmentWrite16 (StartAddress, *(UINT16*)Buffer);
      StartAddress += sizeof (UINT16);
      Size -= sizeof (UINT16);
      Buffer = (UINT16*)Buffer + 1;
    }
  
    if (Size >= sizeof (UINT8)) {
      //
      // Write the last remaining byte if exist
      //
      PciSegmentWrite8 (StartAddress, *(UINT8*)Buffer);
    }
  
    return ReturnValue;
  }
  