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/** @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 - 2010, 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 "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.
**/
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 to 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().
If Port is not aligned on a 16-bit boundary, then ASSERT().
@param Port The I/O port to read.
@return The value read.
**/
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().
If Port is not aligned on a 16-bit boundary, 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 to 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().
If Port is not aligned on a 32-bit boundary, then ASSERT().
@param Port The I/O port to read.
@return The value read.
**/
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().
If Port is not aligned on a 32-bit boundary, 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 to 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;
}