UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/Semaphore.c

   1 /** @file
   2 Semaphore mechanism to indicate to the BSP that an AP has exited SMM
   3 after SMBASE relocation.
   4
   5 Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.<BR>
   6 SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 #include "PiSmmCpuDxeSmm.h"
  11
  12 UINTN             mSmmRelocationOriginalAddress;
  13 volatile BOOLEAN  *mRebasedFlag;
  14
  15 /**
  16   Hook return address of SMM Save State so that semaphore code
  17   can be executed immediately after AP exits SMM to indicate to
  18   the BSP that an AP has exited SMM after SMBASE relocation.
  19
  20   @param[in] CpuIndex     The processor index.
  21   @param[in] RebasedFlag  A pointer to a flag that is set to TRUE
  22                           immediately after AP exits SMM.
  23
  24 **/
  25 VOID
  26 SemaphoreHook (
  27   IN UINTN             CpuIndex,
  28   IN volatile BOOLEAN  *RebasedFlag
  29   )
  30 {
  31   SMRAM_SAVE_STATE_MAP  *CpuState;
  32
  33   mRebasedFlag = RebasedFlag;
  34
  35   CpuState                      = (SMRAM_SAVE_STATE_MAP *)(UINTN)(SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET);
  36   mSmmRelocationOriginalAddress = (UINTN)HookReturnFromSmm (
  37                                            CpuIndex,
  38                                            CpuState,
  39                                            (UINT64)(UINTN)&SmmRelocationSemaphoreComplete,
  40                                            (UINT64)(UINTN)&SmmRelocationSemaphoreComplete
  41                                            );
  42 }