audk/MdePkg/Library/BaseIoLibIntrinsic/IoLibGcc.c

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

  GCC - uses EFIAPI assembler. __asm__ calls GAS. __volatile__ makes sure the
  compiler puts the assembler in this exact location. The complex GNUC
  operations are not optimzed. It would be possible to also write these
  with EFIAPI assembler.

  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"

/**
  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
  )
{
  return *(volatile UINT8*)Address;
}

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

/**
  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 written to the Mmio. It equals to the input
          Value instead of the actual value read back from the
          Mmio.
**/
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
  )
{
  ASSERT ((Address & 3) == 0);
  return *(volatile UINT32*)Address;
}

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

/**
  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;
}



/**
  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.

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

  __asm__ __volatile__ ("inb %w1,%b0" : "=a" (Data) : "d" ((UINT16)Port));
  return Data;
}

/**
  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. It equals to the
          input Value instead of the actual value read back from
          the I/O port.

**/
__inline__
UINT8
EFIAPI
IoWrite8 (
  IN      UINTN                     Port,
  IN      UINT8                     Value
  )
{
  __asm__ __volatile__ ("outb %b0,%w1" : : "a" (Value), "d" ((UINT16)Port));
  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.

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

  ASSERT ((Port & 1) == 0);
  __asm__ __volatile__ ("inw %w1,%w0" : "=a" (Data) : "d" ((UINT16)Port));
  return Data;
}

/**
  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 to the I/O port. It equals to the
          input Value instead of the actual value read back from
          the I/O port.

**/
__inline__
UINT16
EFIAPI
IoWrite16 (
  IN      UINTN                     Port,
  IN      UINT16                    Value
  )
{
  ASSERT ((Port & 1) == 0);
  __asm__ __volatile__ ("outw %w0,%w1" : : "a" (Value), "d" ((UINT16)Port));
  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.

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

  ASSERT ((Port & 3) == 0);
  __asm__ __volatile__ ("inl %w1,%0" : "=a" (Data) : "d" ((UINT16)Port));
  return Data;
}

/**
  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 to the I/O port. It equals to the
          input Value instead of the actual value read back from
          the I/O port.

**/
__inline__
UINT32
EFIAPI
IoWrite32 (
  IN      UINTN                     Port,
  IN      UINT32  Value
  )
{
  ASSERT ((Port & 3) == 0);
  __asm__ __volatile__ ("outl %0,%w1" : : "a" (Value), "d" ((UINT16)Port));
  return Value;
}