Drivers/OpTeeRpmb: Add an OP-TEE backed RPMB driver

A following patch is adding support for building StMM in order to run it
from OP-TEE.
OP-TEE in combination with a NS-world supplicant can use the RPMB
partition of an eMMC to store EFI variables. The supplicant
functionality is currently available in U-Boot only but can be ported
into EDK2. Assuming similar functionality is added in EDK2, this will
allow any hardware with an RPMB partition to store EFI variables
securely.

So let's add a driver that enables access of the RPMB partition through
OP-TEE. Since the upper layers expect a byte addressable interface,
the driver allocates memory and patches the PCDs, while syncing the
memory/hardware on read/write callbacks.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

Author: apalos

Drivers/OpTeeRpmb/FixupPcd.c

@@ -0,0 +1,74 @@
+/** @file
+
+  Update the patched PCDs to their correct value
+
+  Copyright (c) 2020, Linaro Ltd. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+/**
+ * Patch the relevant PCDs of the RPMB driver with the correct address of the
+ * allocated memory
+ *
+**/
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MmServicesTableLib.h>
+#include <Library/PcdLib.h>
+
+#include <Protocol/FirmwareVolumeBlock.h>
+#include <Protocol/SmmFirmwareVolumeBlock.h>
+
+#include "OpTeeRpmbFvb.h"
+
+/**
+  Fixup the Pcd values for variable storage
+
+  Since the upper layers of EDK2 expect a memory mapped interface and we can't
+  offer that from an RPMB, the driver allocates memory on init and passes that
+  on the upper layers. Since the memory is dynamically allocated and we can't set the
+  PCD is StMM context, we need to patch it correctly on each access
+
+  @retval EFI_SUCCESS Protocol was found and PCDs patched up
+
+ **/
+EFI_STATUS
+EFIAPI
+FixPcdMemory (
+  VOID
+  )
+{
+  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *FvbProtocol;
+  MEM_INSTANCE                        *Instance;
+  EFI_STATUS                          Status;
+
+  //
+  // Locate SmmFirmwareVolumeBlockProtocol
+  //
+  Status = gMmst->MmLocateProtocol (
+                    &gEfiSmmFirmwareVolumeBlockProtocolGuid,
+                    NULL,
+                    (VOID **) &FvbProtocol
+                    );
+  ASSERT_EFI_ERROR (Status);
+
+  Instance = INSTANCE_FROM_FVB_THIS(FvbProtocol);
+  // Patch PCDs with the the correct values
+  PatchPcdSet32 (PcdFlashNvStorageVariableBase, Instance->MemBaseAddress);
+  PatchPcdSet32 (PcdFlashNvStorageFtwWorkingBase, Instance->MemBaseAddress +
+    PcdGet32 (PcdFlashNvStorageVariableSize));
+  PatchPcdSet32 (PcdFlashNvStorageFtwSpareBase, Instance->MemBaseAddress +
+    PcdGet32 (PcdFlashNvStorageVariableSize) +
+    PcdGet32 (PcdFlashNvStorageFtwWorkingSize));
+
+  DEBUG ((DEBUG_INFO, "%a: Fixup PcdFlashNvStorageVariableBase: 0x%lx\n",
+    __FUNCTION__, PcdGet32 (PcdFlashNvStorageVariableBase)));
+  DEBUG ((DEBUG_INFO, "%a: Fixup PcdFlashNvStorageFtwWorkingBase: 0x%lx\n",
+    __FUNCTION__, PcdGet32 (PcdFlashNvStorageFtwWorkingBase)));
+  DEBUG ((DEBUG_INFO, "%a: Fixup PcdFlashNvStorageFtwSpareBase: 0x%lx\n",
+    __FUNCTION__, PcdGet32 (PcdFlashNvStorageFtwSpareBase)));
+
+  return Status;
+}

Drivers/OpTeeRpmb/FixupPcd.inf

@@ -0,0 +1,44 @@
+## @file
+#  Instance of Base Memory Library without assembly.
+#
+#  Copyright (c) 2020, Linaro Ltd. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x0001001A
+  BASE_NAME                      = FixupPcd
+  FILE_GUID                      = a827c337-a9c6-301b-aeb7-acbc95d8da22
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 0.1
+  LIBRARY_CLASS                  = RpmbPcdFixup|MM_STANDALONE
+  CONSTRUCTOR                    = FixPcdMemory
+
+[Sources]
+  FixupPcd.c
+  OpTeeRpmbFvb.h
+
+[Packages]
+  MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
+  MmServicesTableLib
+  PcdLib
+
+[Pcd]
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableSize
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingSize
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareSize
+
+
+[Protocols]
+  gEfiSmmFirmwareVolumeBlockProtocolGuid          ## CONSUMES

Drivers/OpTeeRpmb/OpTeeRpmbFv.inf

@@ -0,0 +1,58 @@
+## @file
+#
+#  Component description file for OpTeeRpmbFv module
+#
+#  Copyright (c) 2020, Linaro Ltd. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x0001001A
+  BASE_NAME                      = OpTeeRpmbFv
+  FILE_GUID                      = 4803FC20-E583-3BCD-8C60-141E85C9A2CF
+  MODULE_TYPE                    = MM_STANDALONE
+  VERSION_STRING                 = 0.1
+  PI_SPECIFICATION_VERSION       = 0x00010032
+  ENTRY_POINT                    = OpTeeRpmbFvbInit
+
+[Sources]
+  OpTeeRpmbFvb.c
+  OpTeeRpmbFvb.h
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  ArmPlatformPkg/ArmPlatformPkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
+  StandaloneMmPkg/StandaloneMmPkg.dec
+
+[LibraryClasses]
+  ArmSvcLib
+  BaseLib
+  BaseMemoryLib
+  DebugLib
+  MemoryAllocationLib
+  MmServicesTableLib
+  PcdLib
+  StandaloneMmDriverEntryPoint
+
+[Guids]
+  gEfiAuthenticatedVariableGuid
+  gEfiSystemNvDataFvGuid
+  gEfiVariableGuid
+
+[Pcd]
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableSize
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingSize
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareSize
+
+[Protocols]
+  gEfiSmmFirmwareVolumeBlockProtocolGuid          ## PRODUCES
+
+[Depex]
+  TRUE