[PATCH v2 1/6] MdeModulePkg: DxeMmUnblockMemoryLib: Added definition and null instance

["Kun Qin" <kun.q@outlook.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3168

This interface definition provides an abstraction layer for DXE drivers
to request certain memory blocks to be mapped/unblocked for accessibility
inside MM environment.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>

Signed-off-by: Kun Qin <kun.q@outlook.com>
---

Notes:
    v2:
    - Resend with practical usage. No change [Hao]

 MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.c   | 40 ++++++++++++++++++++
 MdeModulePkg/Include/Library/DxeMmUnblockMemoryLib.h                     | 40 ++++++++++++++++++++
 MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.inf | 29 ++++++++++++++
 MdeModulePkg/MdeModulePkg.dec                                            |  5 +++
 MdeModulePkg/MdeModulePkg.dsc                                            |  2 +
 5 files changed, 116 insertions(+)

diff --git a/MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.c b/MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.c
new file mode 100644
index 000000000000..774a7e41cfb0
--- /dev/null
+++ b/MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.c
@@ -0,0 +1,40 @@
+/** @file
+  Null instance of MM Unblock Page Library.
+
+  This library provides an abstraction layer of requesting certain page access to be unblocked
+  by MM environment if applicable.
+
+  Copyright (c), Microsoft Corporation.
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+
+/**
+  This API provides a way to unblock certain data pages to be accessible inside MM environment.
+
+  @param  UnblockAddress          The address of buffer caller requests to unblock, the address
+                                  has to be page aligned.
+  @param  NumberOfPages           The number of pages requested to be unblocked from MM
+                                  environment.
+
+  @return EFI_SUCCESS             The request goes through successfully.
+  @return EFI_NOT_AVAILABLE_YET   The requested functionality is not produced yet.
+  @return EFI_UNSUPPORTED         The requested functionality is not supported on current platform.
+  @return EFI_SECURITY_VIOLATION  The requested address failed to pass security check for
+                                  unblocking.
+  @return EFI_INVALID_PARAMETER   Input address either NULL pointer or not page aligned.
+  @return EFI_ACCESS_DENIED       The request is rejected due to system has passed certain boot
+                                  phase.
+
+**/
+EFI_STATUS
+EFIAPI
+DxeMmUnblockMemoryRequest (
+  IN EFI_PHYSICAL_ADDRESS   UnblockAddress,
+  IN UINT64                 NumberOfPages
+  )
+{
+  return EFI_UNSUPPORTED;
+}
diff --git a/MdeModulePkg/Include/Library/DxeMmUnblockMemoryLib.h b/MdeModulePkg/Include/Library/DxeMmUnblockMemoryLib.h
new file mode 100644
index 000000000000..8b63eb74a078
--- /dev/null
+++ b/MdeModulePkg/Include/Library/DxeMmUnblockMemoryLib.h
@@ -0,0 +1,40 @@
+/** @file
+  MM Unblock Memory Library Interface.
+
+  This library provides an abstraction layer of requesting certain page access to be unblocked
+  by MM environment if applicable.
+
+  Copyright (c), Microsoft Corporation.
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef _DXE_MM_UNBLOCK_MEMORY_LIB_H_
+#define _DXE_MM_UNBLOCK_MEMORY_LIB_H_
+
+/**
+  This API provides a way to unblock certain data pages to be accessible inside MM environment.
+
+  @param  UnblockAddress          The address of buffer caller requests to unblock, the address
+                                  has to be page aligned.
+  @param  NumberOfPages           The number of pages requested to be unblocked from MM
+                                  environment.
+
+  @return EFI_SUCCESS             The request goes through successfully.
+  @return EFI_NOT_AVAILABLE_YET   The requested functionality is not produced yet.
+  @return EFI_UNSUPPORTED         The requested functionality is not supported on current platform.
+  @return EFI_SECURITY_VIOLATION  The requested address failed to pass security check for
+                                  unblocking.
+  @return EFI_INVALID_PARAMETER   Input address either NULL pointer or not page aligned.
+  @return EFI_ACCESS_DENIED       The request is rejected due to system has passed certain boot
+                                  phase.
+
+**/
+EFI_STATUS
+EFIAPI
+DxeMmUnblockMemoryRequest (
+  IN EFI_PHYSICAL_ADDRESS   UnblockAddress,
+  IN UINT64                 NumberOfPages
+);
+
+#endif // _DXE_MM_UNBLOCK_MEMORY_LIB_H_
diff --git a/MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.inf b/MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.inf
new file mode 100644
index 000000000000..e40462e5ab81
--- /dev/null
+++ b/MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.inf
@@ -0,0 +1,29 @@
+## @file
+#  Null instance of MM Unblock Page Library.
+#
+#  This library provides an abstraction layer of requesting certain page access to be unblocked
+#  by MM environment if applicable.
+#
+#  Copyright (c), Microsoft Corporation.
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x0001001B
+  BASE_NAME                      = DxeMmUnblockMemoryLibNull
+  FILE_GUID                      = 9E890F68-5C95-4C31-95DD-59E6286F85EA
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = DxeMmUnblockMemoryLib
+
+#
+#  VALID_ARCHITECTURES           = IA32 X64
+#
+
+[Sources]
+  DxeMmUnblockMemoryLibNull.c
+
+[Packages]
+  MdePkg/MdePkg.dec
diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 148395511034..1bb5017da2c5 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -154,6 +154,11 @@ [LibraryClasses]
   #
   VariablePolicyHelperLib|Include/Library/VariablePolicyHelperLib.h
 
+  ##  @libraryclass  This library provides an interface for DXE drivers to request MM environment
+  #   to map/unblock a memory region for accessibility inside MM.
+  #
+  DxeMmUnblockMemoryLib|Include/Library/DxeMmUnblockMemoryLib.h
+
 [Guids]
   ## MdeModule package token space guid
   # Include/Guid/MdeModulePkgTokenSpace.h
diff --git a/MdeModulePkg/MdeModulePkg.dsc b/MdeModulePkg/MdeModulePkg.dsc
index 7ca4a1bb3080..2bc6b8730b8b 100644
--- a/MdeModulePkg/MdeModulePkg.dsc
+++ b/MdeModulePkg/MdeModulePkg.dsc
@@ -100,6 +100,7 @@ [LibraryClasses]
   SafeIntLib|MdePkg/Library/BaseSafeIntLib/BaseSafeIntLib.inf
   DisplayUpdateProgressLib|MdeModulePkg/Library/DisplayUpdateProgressLibGraphics/DisplayUpdateProgressLibGraphics.inf
   VariablePolicyHelperLib|MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.inf
+  DxeMmUnblockMemoryLib|MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.inf
 
 [LibraryClasses.EBC.PEIM]
   IoLib|MdePkg/Library/PeiIoLibCpuIo/PeiIoLibCpuIo.inf
@@ -332,6 +333,7 @@ [Components]
   MdeModulePkg/Library/BaseBmpSupportLib/BaseBmpSupportLib.inf
   MdeModulePkg/Library/DisplayUpdateProgressLibGraphics/DisplayUpdateProgressLibGraphics.inf
   MdeModulePkg/Library/DisplayUpdateProgressLibText/DisplayUpdateProgressLibText.inf
+  MdeModulePkg/Library/DxeMmUnblockMemoryLib/DxeMmUnblockMemoryLibNull.inf
 
   MdeModulePkg/Universal/BdsDxe/BdsDxe.inf
   MdeModulePkg/Application/BootManagerMenuApp/BootManagerMenuApp.inf
-- 
2.30.0.windows.1