MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeCache.h

   1 /** @file
   2   The common variable volatile store routines shared by the DXE_RUNTIME variable
   3   module and the DXE_SMM variable module.
   4
   5 Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
   6 SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 #ifndef _VARIABLE_RUNTIME_CACHE_H_
  11 #define _VARIABLE_RUNTIME_CACHE_H_
  12
  13 #include "Variable.h"
  14
  15 /**
  16   Copies any pending updates to runtime variable caches.
  17
  18   @retval EFI_UNSUPPORTED         The volatile store to be updated is not initialized properly.
  19   @retval EFI_SUCCESS             The volatile store was updated successfully.
  20
  21 **/
  22 EFI_STATUS
  23 FlushPendingRuntimeVariableCacheUpdates (
  24   VOID
  25   );
  26
  27 /**
  28   Synchronizes the runtime variable caches with all pending updates outside runtime.
  29
  30   Ensures all conditions are met to maintain coherency for runtime cache updates. This function will attempt
  31   to write the given update (and any other pending updates) if the ReadLock is available. Otherwise, the
  32   update is added as a pending update for the given variable store and it will be flushed to the runtime cache
  33   at the next opportunity the ReadLock is available.
  34
  35   @param[in] VariableRuntimeCache Variable runtime cache structure for the runtime cache being synchronized.
  36   @param[in] Offset               Offset in bytes to apply the update.
  37   @param[in] Length               Length of data in bytes of the update.
  38
  39   @retval EFI_SUCCESS             The update was added as a pending update successfully. If the variable runtime
  40                                   cache ReadLock was available, the runtime cache was updated successfully.
  41   @retval EFI_UNSUPPORTED         The volatile store to be updated is not initialized properly.
  42
  43 **/
  44 EFI_STATUS
  45 SynchronizeRuntimeVariableCache (
  46   IN  VARIABLE_RUNTIME_CACHE          *VariableRuntimeCache,
  47   IN  UINTN                           Offset,
  48   IN  UINTN                           Length
  49   );
  50
  51 #endif