audk/MdePkg/Library/BaseIoLibIntrinsic/IoLibMsc.c

/** @file
  I/O Library. This file has compiler specifics for Microsft C as there is no
  ANSI C standard for doing IO.

  MSC - uses intrinsic functions and the optimize will remove the function call
  overhead.

  We don't advocate putting compiler specifics in libraries or drivers but there
  is no other way to make this work.

  Copyright (c) 2006 - 2007, Intel Corporation<BR>
  All rights reserved. This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/



#include "BaseIoLibIntrinsicInternal.h"

//
// Microsoft Visual Studio 7.1 Function Prototypes for I/O Intrinsics.
//

int            _inp (unsigned short port);
unsigned short _inpw (unsigned short port);
unsigned long  _inpd (unsigned short port);
int            _outp (unsigned short port, int databyte );
unsigned short _outpw (unsigned short port, unsigned short dataword );
unsigned long  _outpd (unsigned short port, unsigned long dataword );
void          _ReadWriteBarrier (void);

#pragma intrinsic(_inp)
#pragma intrinsic(_inpw)
#pragma intrinsic(_inpd)
#pragma intrinsic(_outp)
#pragma intrinsic(_outpw)
#pragma intrinsic(_outpd)
#pragma intrinsic(_ReadWriteBarrier)

//
// _ReadWriteBarrier() forces memory reads and writes to complete at the point
// in the call. This is only a hint to the compiler and does emit code.
// In past versions of the compiler, _ReadWriteBarrier was enforced only
// locally and did not affect functions up the call tree. In Visual C++
// 2005, _ReadWriteBarrier is enforced all the way up the call tree.
//

/**
  Reads an 8-bit I/O port.

  Reads the 8-bit I/O port specified by Port. The 8-bit read value is returned.
  This function must guarantee that all I/O read and write operations are
  serialized.

  If 8-bit I/O port operations are not supported, then ASSERT().

  @param  Port  The I/O port to read.

  @return The value read from Port.

**/
UINT8
EFIAPI
IoRead8 (
  IN      UINTN                     Port
  )
{
  UINT8                             Value;

  _ReadWriteBarrier ();
  Value = (UINT8)_inp ((UINT16)Port);
  _ReadWriteBarrier ();
  return Value;
}

/**
  Writes an 8-bit I/O port.

  Writes the 8-bit I/O port specified by Port with the value specified by Value
  and returns Value. This function must guarantee that all I/O read and write
  operations are serialized.

  If 8-bit I/O port operations are not supported, then ASSERT().

  @param  Port  The I/O port to write.
  @param  Value The value to write to the I/O port.

  @return The value written the I/O port.

**/
UINT8
EFIAPI
IoWrite8 (
  IN      UINTN                     Port,
  IN      UINT8                     Value
  )
{
  _ReadWriteBarrier ();
  (UINT8)_outp ((UINT16)Port, Value);
  _ReadWriteBarrier ();
  return Value;
}

/**
  Reads a 16-bit I/O port.

  Reads the 16-bit I/O port specified by Port. The 16-bit read value is returned.
  This function must guarantee that all I/O read and write operations are
  serialized.

  If 16-bit I/O port operations are not supported, then ASSERT().

  @param  Port  The I/O port to read.

  @return The value read from Port.

**/
UINT16
EFIAPI
IoRead16 (
  IN      UINTN                     Port
  )
{
  UINT16                            Value;

  ASSERT ((Port & 1) == 0);
  _ReadWriteBarrier ();
  Value = _inpw ((UINT16)Port);
  _ReadWriteBarrier ();
  return Value;
}

/**
  Writes a 16-bit I/O port.

  Writes the 16-bit I/O port specified by Port with the value specified by Value
  and returns Value. This function must guarantee that all I/O read and write
  operations are serialized.

  If 16-bit I/O port operations are not supported, then ASSERT().

  @param  Port  The I/O port to write.
  @param  Value The value to write to the I/O port.

  @return The value written the I/O port.

**/
UINT16
EFIAPI
IoWrite16 (
  IN      UINTN                     Port,
  IN      UINT16                    Value
  )
{
  ASSERT ((Port & 1) == 0);
  _ReadWriteBarrier ();
  _outpw ((UINT16)Port, Value);
  _ReadWriteBarrier ();
  return Value;
}

/**
  Reads a 32-bit I/O port.

  Reads the 32-bit I/O port specified by Port. The 32-bit read value is returned.
  This function must guarantee that all I/O read and write operations are
  serialized.

  If 32-bit I/O port operations are not supported, then ASSERT().

  @param  Port  The I/O port to read.

  @return The value read from Port.

**/
UINT32
EFIAPI
IoRead32 (
  IN      UINTN                     Port
  )
{
  UINT32                            Value;

  ASSERT ((Port & 3) == 0);
  _ReadWriteBarrier ();
  Value = _inpd ((UINT16)Port);
  _ReadWriteBarrier ();
  return Value;
}

/**
  Writes a 32-bit I/O port.

  Writes the 32-bit I/O port specified by Port with the value specified by Value
  and returns Value. This function must guarantee that all I/O read and write
  operations are serialized.

  If 32-bit I/O port operations are not supported, then ASSERT().

  @param  Port  The I/O port to write.
  @param  Value The value to write to the I/O port.

  @return The value written the I/O port.

**/
UINT32
EFIAPI
IoWrite32 (
  IN      UINTN                     Port,
  IN      UINT32                    Value
  )
{
  ASSERT ((Port & 3) == 0);
  _ReadWriteBarrier ();
  _outpd ((UINT16)Port, Value);
  _ReadWriteBarrier ();
  return Value;
}


/**
  Reads an 8-bit MMIO register.

  Reads the 8-bit MMIO register specified by Address. The 8-bit read value is
  returned. This function must guarantee that all MMIO read and write
  operations are serialized.

  If 8-bit MMIO register operations are not supported, then ASSERT().

  @param  Address The MMIO register to read.

  @return The value read from Address.

**/
UINT8
EFIAPI
MmioRead8 (
  IN      UINTN                     Address
  )
{
  UINT8                             Value;

  Value = *(volatile UINT8*)Address;
  return Value;
}

/**
  Writes an 8-bit MMIO register.

  Writes the 8-bit MMIO register specified by Address with the value specified
  by Value and returns Value. This function must guarantee that all MMIO read
  and write operations are serialized.

  If 8-bit MMIO register operations are not supported, then ASSERT().

  @param  Address The MMIO register to write.
  @param  Value   The value to write to the MMIO register.
  
  @return The value written to the Mmio. It equals to the input
          Value instead of the actual value read back from the
          Mmio.
  
**/
UINT8
EFIAPI
MmioWrite8 (
  IN      UINTN                     Address,
  IN      UINT8                     Value
  )
{
  return *(volatile UINT8*)Address = Value;
}

/**
  Reads a 16-bit MMIO register.

  Reads the 16-bit MMIO register specified by Address. The 16-bit read value is
  returned. This function must guarantee that all MMIO read and write
  operations are serialized.

  If 16-bit MMIO register operations are not supported, then ASSERT().

  @param  Address The MMIO register to read.

  @return The value read from Address.

**/
UINT16
EFIAPI
MmioRead16 (
  IN      UINTN                     Address
  )
{
  UINT16                            Value;

  ASSERT ((Address & 1) == 0);
  Value = *(volatile UINT16*)Address;
  return Value;
}

/**
  Writes a 16-bit MMIO register.

  Writes the 16-bit MMIO register specified by Address with the value specified
  by Value and returns Value. This function must guarantee that all MMIO read
  and write operations are serialized.

  If 16-bit MMIO register operations are not supported, then ASSERT().

  @param  Address The MMIO register to write.
  @param  Value   The value to write to the MMIO register.
  
  @return The value read from the Mmio after wrote specified
          Value.

**/
UINT16
EFIAPI
MmioWrite16 (
  IN      UINTN                     Address,
  IN      UINT16                    Value
  )
{
  ASSERT ((Address & 1) == 0);
  return *(volatile UINT16*)Address = Value;
}

/**
  Reads a 32-bit MMIO register.

  Reads the 32-bit MMIO register specified by Address. The 32-bit read value is
  returned. This function must guarantee that all MMIO read and write
  operations are serialized.

  If 32-bit MMIO register operations are not supported, then ASSERT().

  @param  Address The MMIO register to read.

  @return The value read from Address.

**/
UINT32
EFIAPI
MmioRead32 (
  IN      UINTN                     Address
  )
{
  UINT32                            Value;

  ASSERT ((Address & 3) == 0);
  Value = *(volatile UINT32*)Address;
  return Value;
}

/**
  Writes a 32-bit MMIO register.

  Writes the 32-bit MMIO register specified by Address with the value specified
  by Value and returns Value. This function must guarantee that all MMIO read
  and write operations are serialized.

  If 32-bit MMIO register operations are not supported, then ASSERT().

  @param  Address The MMIO register to write.
  @param  Value   The value to write to the MMIO register.
  
  @return The value written to the Mmio. It equals to the input
          Value instead of the actual value read back from the
          Mmio.

**/
UINT32
EFIAPI
MmioWrite32 (
  IN      UINTN                     Address,
  IN      UINT32                    Value
  )
{
  ASSERT ((Address & 3) == 0);
  return *(volatile UINT32*)Address = Value;
}

/**
  Reads a 64-bit MMIO register.

  Reads the 64-bit MMIO register specified by Address. The 64-bit read value is
  returned. This function must guarantee that all MMIO read and write
  operations are serialized.

  If 64-bit MMIO register operations are not supported, then ASSERT().

  @param  Address The MMIO register to read.

  @return The value read from Address.

**/
UINT64
EFIAPI
MmioRead64 (
  IN      UINTN                     Address
  )
{
  UINT64                            Value;

  ASSERT ((Address & 7) == 0);
  Value = *(volatile UINT64*)Address;
  return Value;
}

/**
  Writes a 64-bit MMIO register.

  Writes the 64-bit MMIO register specified by Address with the value specified
  by Value and returns Value. This function must guarantee that all MMIO read
  and write operations are serialized.

  If 64-bit MMIO register operations are not supported, then ASSERT().

  @param  Address The MMIO register to write.
  @param  Value   The value to write to the MMIO register.

  @return The value written to the Mmio. It equals to the input
          Value instead of the actual value read back from the
          Mmio.
  
**/
UINT64
EFIAPI
MmioWrite64 (
  IN      UINTN                     Address,
  IN      UINT64                    Value
  )
{
  ASSERT ((Address & 7) == 0);
  return *(volatile UINT64*)Address = Value;
}