MdePkg/SmmIoLib: Add header file.

This SmmIoLib is used to check if an IO resource
is valid in SMM.

Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>

MdePkg/Include/Library/SmmIoLib.h

@@ -0,0 +1,42 @@
+/** @file
+  Provides services for SMM IO Operation.
+
+  The SMM IO Library provides function for checking if IO resource is accessible inside of SMM.
+
+  Copyright (c) 2017, 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.
+
+**/
+
+#ifndef _SMM_IO_LIB_H_
+#define _SMM_IO_LIB_H_
+
+/**
+  This function check if the MMIO resource is valid per processor architecture and
+  valid per platform design.
+
+  @param BaseAddress  The MMIO start address to be checked.
+  @param Length       The MMIO length to be checked.
+  @param Owner        A GUID representing the owner of the resource.
+                      This GUID may be used by producer to correlate the device ownership of the resource.
+                      NULL means no specific owner.
+
+  @retval TRUE  This MMIO resource is valid per processor architecture and valid per platform design.
+  @retval FALSE This MMIO resource is not valid per processor architecture or valid per platform design.
+**/
+BOOLEAN
+EFIAPI
+SmmIsMmioValid (
+  IN EFI_PHYSICAL_ADDRESS  BaseAddress,
+  IN UINT64                Length,
+  IN EFI_GUID              *Owner  OPTIONAL
+  );
+
+#endif
+