05a5379458
The VMWare SVGA display device implemented by Qemu (-vga vmware) uses an I/O-type BAR which is laid out such that some register offsets are not aligned to the read/write width with which they are expected to be accessed. (The register value port has an offset of 1 and requires 32 bit wide read/write access.) The EFI_PCI_IO_PROTOCOL's Io.Read/Io.Write functions do not support such unaligned I/O. Before a driver for this device can be added to QemuVideoDxe, helper functions for unaligned I/O are therefore required. This adds the functions UnalignedIoWrite32 and UnalignedIoRead32, based on IoLib's IoWrite32 and IoRead32, for the Ia32 and X64 architectures. Port I/O requires inline assembly, so implementations are provided for the GCC, ICC, and Microsoft compiler families. Such I/O is not possible on other architectures, a dummy (ASSERT()ing) implementation is therefore provided to satisfy the linker. Cc: Jordan Justen <jordan.l.justen@intel.com> Cc: Laszlo Ersek <lersek@redhat.com> Suggested-by: Jordan Justen <jordan.l.justen@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
79 lines
2.2 KiB
C
79 lines
2.2 KiB
C
/** @file
|
|
Unaligned port I/O. This file has compiler specifics for Microsoft C as there
|
|
is no ANSI C standard for doing IO.
|
|
|
|
Based on IoLibMsc.c
|
|
|
|
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 "UnalignedIoInternal.h"
|
|
|
|
unsigned long _inpd (unsigned short port);
|
|
unsigned long _outpd (unsigned short port, unsigned long dataword );
|
|
void _ReadWriteBarrier (void);
|
|
|
|
/**
|
|
Performs a 32-bit write to the specified, possibly unaligned I/O-type
|
|
address.
|
|
|
|
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 unaligned I/O port operations are not supported, then ASSERT().
|
|
|
|
@param[in] Port I/O port address
|
|
@param[in] Value 32-bit word to write
|
|
|
|
@return The value written to the I/O port.
|
|
|
|
**/
|
|
UINT32
|
|
UnalignedIoWrite32 (
|
|
IN UINTN Port,
|
|
IN UINT32 Value
|
|
)
|
|
{
|
|
_ReadWriteBarrier ();
|
|
_outpd ((UINT16)Port, Value);
|
|
_ReadWriteBarrier ();
|
|
return Value;
|
|
}
|
|
|
|
/**
|
|
Reads a 32-bit word from the specified, possibly unaligned I/O-type address.
|
|
|
|
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 unaligned I/O port operations are not supported, then ASSERT().
|
|
|
|
@param[in] Port The I/O port to read.
|
|
|
|
@return The value read.
|
|
|
|
**/
|
|
UINT32
|
|
UnalignedIoRead32 (
|
|
IN UINTN Port
|
|
)
|
|
{
|
|
UINT32 Value;
|
|
|
|
_ReadWriteBarrier ();
|
|
Value = _inpd ((UINT16)Port);
|
|
_ReadWriteBarrier ();
|
|
return Value;
|
|
}
|