UefiCpuPkg/Library/SmmCpuPlatformHookLibNull/SmmCpuPlatformHookLibNull.c

   1 /** @file
   2 SMM CPU Platform Hook NULL library instance.
   3
   4 Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
   5 SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8 #include <PiSmm.h>
   9 #include <Library/SmmCpuPlatformHookLib.h>
  10
  11 /**
  12   Checks if platform produces a valid SMI.
  13
  14   This function checks if platform produces a valid SMI. This function is
  15   called at SMM entry to detect if this is a spurious SMI. This function
  16   must be implemented in an MP safe way because it is called by multiple CPU
  17   threads.
  18
  19   @retval TRUE              There is a valid SMI
  20   @retval FALSE             There is no valid SMI
  21
  22 **/
  23 BOOLEAN
  24 EFIAPI
  25 PlatformValidSmi (
  26   VOID
  27   )
  28 {
  29   return TRUE;
  30 }
  31
  32 /**
  33   Clears platform top level SMI status bit.
  34
  35   This function clears platform top level SMI status bit.
  36
  37   @retval TRUE              The platform top level SMI status is cleared.
  38   @retval FALSE             The platform top level SMI status cannot be cleared.
  39
  40 **/
  41 BOOLEAN
  42 EFIAPI
  43 ClearTopLevelSmiStatus (
  44   VOID
  45   )
  46 {
  47   return TRUE;
  48 }
  49
  50 /**
  51   Performs platform specific way of SMM BSP election.
  52
  53   This function performs platform specific way of SMM BSP election.
  54
  55   @param  IsBsp             Output parameter. TRUE: the CPU this function executes
  56                             on is elected to be the SMM BSP. FALSE: the CPU this
  57                             function executes on is to be SMM AP.
  58
  59   @retval EFI_SUCCESS       The function executes successfully.
  60   @retval EFI_NOT_READY     The function does not determine whether this CPU should be
  61                             BSP or AP. This may occur if hardware init sequence to
  62                             enable the determination is yet to be done, or the function
  63                             chooses not to do BSP election and will let SMM CPU driver to
  64                             use its default BSP election process.
  65   @retval EFI_DEVICE_ERROR  The function cannot determine whether this CPU should be
  66                             BSP or AP due to hardware error.
  67
  68 **/
  69 EFI_STATUS
  70 EFIAPI
  71 PlatformSmmBspElection (
  72   OUT BOOLEAN  *IsBsp
  73   )
  74 {
  75   return EFI_NOT_READY;
  76 }
  77
  78 /**
  79   Get platform page table attribute.
  80
  81   This function gets page table attribute of platform.
  82
  83   @param  Address        Input parameter. Obtain the page table entries attribute on this address.
  84   @param  PageSize       Output parameter. The size of the page.
  85   @param  NumOfPages     Output parameter. Number of page.
  86   @param  PageAttribute  Output parameter. Paging Attributes (WB, UC, etc).
  87
  88   @retval EFI_SUCCESS      The platform page table attribute from the address is determined.
  89   @retval EFI_UNSUPPORTED  The platform does not support getting page table attribute for the address.
  90
  91 **/
  92 EFI_STATUS
  93 EFIAPI
  94 GetPlatformPageTableAttribute (
  95   IN  UINT64                 Address,
  96   IN OUT SMM_PAGE_SIZE_TYPE  *PageSize,
  97   IN OUT UINTN               *NumOfPages,
  98   IN OUT UINTN               *PageAttribute
  99   )
 100 {
 101   return EFI_UNSUPPORTED;
 102 }