Reapply "OvmfPkg/QemuVideoDxe: Helper functions for unaligned port I/O."

This reverts commit 438ada5aa5,
reapplying 05a5379458.

Note that the commit now being reverted is technically correct; the only
reason we're reverting it is because it should not have been pushed past
the Soft Feature Freeze for the edk2-stable201811 tag.

Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Julien Grall <julien.grall@linaro.org>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Cc: yuchenlin <yuchenlin@synology.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1319
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: yuchenlin <yuchenlin@synology.com>

OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf

@@ -41,9 +41,15 @@
   Qemu.h
 
 [Sources.Ia32, Sources.X64]
+  UnalignedIoGcc.c    | GCC
+  UnalignedIoIcc.c    | INTEL
+  UnalignedIoMsc.c    | MSFT
   VbeShim.c
   VbeShim.h
 
+[Sources.EBC]
+  UnalignedIoUnsupported.c
+
 [Packages]
   MdePkg/MdePkg.dec
   MdeModulePkg/MdeModulePkg.dec

OvmfPkg/QemuVideoDxe/UnalignedIoGcc.c

@@ -0,0 +1,70 @@
+/** @file
+  Unaligned Port I/O. This file has compiler specifics for GCC as there is no
+  ANSI C standard for doing IO.
+
+  Based on IoLibGcc.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"
+
+/**
+  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
+  )
+{
+  __asm__ __volatile__ ( "outl %0, %1" : : "a" (Value), "d" ((UINT16)Port) );
+  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 Data;
+  __asm__ __volatile__ ( "inl %1, %0" : "=a" (Data) : "d" ((UINT16)Port) );
+  return Data;
+}
+

OvmfPkg/QemuVideoDxe/UnalignedIoIcc.c

@@ -0,0 +1,80 @@
+/** @file
+  Unaligned port I/O. This file has compiler specifics for ICC as there
+  is no ANSI C standard for doing IO.
+
+  Based on IoLibIcc.c.
+
+  Copyright (c) 2006 - 2008, 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"
+
+/**
+  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
+  )
+{
+  __asm {
+    mov eax, dword ptr [Value]
+    mov dx, word ptr [Port]
+    out dx, eax
+  }
+
+  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 Data;
+
+  __asm {
+    mov dx, word ptr [Port]
+    in  eax, dx
+    mov dword ptr [Data], eax
+  }
+
+  return Data;
+}

OvmfPkg/QemuVideoDxe/UnalignedIoInternal.h

@@ -0,0 +1,59 @@
+/** @file
+  Unaligned port I/O, with implementations for various x86 compilers and a
+  dummy for platforms which do not support unaligned port I/O.
+
+  Copyright (c) 2017, Phil Dennis-Jordan.<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.
+
+**/
+
+#ifndef _UNALIGNED_IO_INTERNAL_H_
+#define _UNALIGNED_IO_INTERNAL_H_
+
+/**
+  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
+  );
+
+/**
+  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
+  );
+
+#endif

OvmfPkg/QemuVideoDxe/UnalignedIoMsc.c

@@ -0,0 +1,78 @@
+/** @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;
+}

OvmfPkg/QemuVideoDxe/UnalignedIoUnsupported.c

@@ -0,0 +1,66 @@
+/** @file
+  Unaligned port I/O dummy implementation for platforms which do not support it.
+
+  Copyright (c) 2017, Phil Dennis-Jordan.<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 <Library/DebugLib.h>
+#include "UnalignedIoInternal.h"
+
+/**
+  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
+  )
+{
+  ASSERT (FALSE);
+  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
+  )
+{
+  ASSERT (FALSE);
+  return 0;
+}