UefiCpuPkg/PiSmmCpuDxeSmm/X64/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 X86_ASSEMBLY_PATCH_LABEL gPatchSmmRelocationOriginalAddressPtr32;
  13 X86_ASSEMBLY_PATCH_LABEL gPatchRebasedFlagAddr32;
  14
  15 UINTN             mSmmRelocationOriginalAddress;
  16 volatile BOOLEAN  *mRebasedFlag;
  17
  18 /**
  19 AP Semaphore operation in 32-bit mode while BSP runs in 64-bit mode.
  20 **/
  21 VOID
  22 SmmRelocationSemaphoreComplete32 (
  23   VOID
  24   );
  25
  26 /**
  27   Hook return address of SMM Save State so that semaphore code
  28   can be executed immediately after AP exits SMM to indicate to
  29   the BSP that an AP has exited SMM after SMBASE relocation.
  30
  31   @param[in] CpuIndex     The processor index.
  32   @param[in] RebasedFlag  A pointer to a flag that is set to TRUE
  33                           immediately after AP exits SMM.
  34
  35 **/
  36 VOID
  37 SemaphoreHook (
  38   IN UINTN             CpuIndex,
  39   IN volatile BOOLEAN  *RebasedFlag
  40   )
  41 {
  42   SMRAM_SAVE_STATE_MAP  *CpuState;
  43   UINTN                 TempValue;
  44
  45   mRebasedFlag       = RebasedFlag;
  46   PatchInstructionX86 (
  47     gPatchRebasedFlagAddr32,
  48     (UINT32)(UINTN)mRebasedFlag,
  49     4
  50     );
  51
  52   CpuState = (SMRAM_SAVE_STATE_MAP *)(UINTN)(SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET);
  53   mSmmRelocationOriginalAddress = HookReturnFromSmm (
  54                                     CpuIndex,
  55                                     CpuState,
  56                                     (UINT64)(UINTN)&SmmRelocationSemaphoreComplete32,
  57                                     (UINT64)(UINTN)&SmmRelocationSemaphoreComplete
  58                                     );
  59
  60   //
  61   // Use temp value to fix ICC complier warning
  62   //
  63   TempValue = (UINTN)&mSmmRelocationOriginalAddress;
  64   PatchInstructionX86 (
  65     gPatchSmmRelocationOriginalAddressPtr32,
  66     (UINT32)TempValue,
  67     4
  68     );
  69 }