MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.c

   1 /** @file
   2   Null instance of MM Unblock Page Library.
   3
   4   This library provides an interface to request non-MMRAM pages to be mapped/unblocked
   5   from inside MM environment.
   6
   7   For MM modules that need to access regions outside of MMRAMs, the agents that set up
   8   these regions are responsible for invoking this API in order for these memory areas
   9   to be accessed from inside MM.
  10
  11   Copyright (c) Microsoft Corporation.
  12   SPDX-License-Identifier: BSD-2-Clause-Patent
  13
  14 **/
  15
  16 #include <Base.h>
  17
  18 /**
  19   This API provides a way to unblock certain data pages to be accessible inside MM environment.
  20
  21   @param  UnblockAddress              The address of buffer caller requests to unblock, the address
  22                                       has to be page aligned.
  23   @param  NumberOfPages               The number of pages requested to be unblocked from MM
  24                                       environment.
  25
  26   @retval RETURN_SUCCESS              The request goes through successfully.
  27   @retval RETURN_NOT_AVAILABLE_YET    The requested functionality is not produced yet.
  28   @retval RETURN_UNSUPPORTED          The requested functionality is not supported on current platform.
  29   @retval RETURN_SECURITY_VIOLATION   The requested address failed to pass security check for
  30                                       unblocking.
  31   @retval RETURN_INVALID_PARAMETER    Input address either NULL pointer or not page aligned.
  32   @retval RETURN_ACCESS_DENIED        The request is rejected due to system has passed certain boot
  33                                       phase.
  34
  35 **/
  36 RETURN_STATUS
  37 EFIAPI
  38 MmUnblockMemoryRequest (
  39   IN PHYSICAL_ADDRESS  UnblockAddress,
  40   IN UINT64            NumberOfPages
  41   )
  42 {
  43   return RETURN_UNSUPPORTED;
  44 }