Vlv2TbltDevicePkg/SmramSaveInfoHandlerSmm/SmramSaveInfoHandlerSmm.c

   1 /** @file
   2   A helper driver to save information to SMRAM after SMRR is enabled.
   3
   4   This driver is for ECP platforms.
   5
   6   Copyright (c) 2010 - 2015, Intel Corporation. All rights reserved.<BR>
   7
   8   SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10
  11
  12 **/
  13
  14 #include <PiSmm.h>
  15 #include <Library/DebugLib.h>
  16 #include <Library/UefiDriverEntryPoint.h>
  17 #include <Library/UefiRuntimeServicesTableLib.h>
  18 #include <Library/SmmServicesTableLib.h>
  19 #include <Library/BaseLib.h>
  20 #include <Library/BaseMemoryLib.h>
  21 #include <Library/IoLib.h>
  22 #include <Protocol/SmmSwDispatch.h>
  23 #include <Protocol/SmmReadyToLock.h>
  24 #include <Protocol/SmmControl.h>
  25 #include <Guid/Vlv2DeviceRefCodePkgTokenSpace.h>
  26
  27 #define SMM_FROM_SMBASE_DRIVER        0x55
  28 #define SMM_FROM_CPU_DRIVER_SAVE_INFO 0x81
  29
  30 #define EFI_SMRAM_CPU_NVS_HEADER_GUID \
  31   { \
  32     0x429501d9, 0xe447, 0x40f4, 0x86, 0x7b, 0x75, 0xc9, 0x3a, 0x1d, 0xb5, 0x4e \
  33   }
  34
  35 UINT8    mSmiDataRegister;
  36 BOOLEAN  mLocked = FALSE;
  37 EFI_GUID mSmramCpuNvsHeaderGuid = EFI_SMRAM_CPU_NVS_HEADER_GUID;
  38
  39 /**
  40   Dispatch function for a Software SMI handler.
  41
  42   @param  DispatchHandle        The handle of this dispatch function.
  43   @param  DispatchContext       The pointer to the dispatch function's context.
  44                                 The SwSmiInputValue field is filled in
  45                                 by the software dispatch driver prior to
  46                                 invoking this dispatch function.
  47                                 The dispatch function will only be called
  48                                 for input values for which it is registered.
  49
  50   @return None
  51
  52 **/
  53 VOID
  54 EFIAPI
  55 SmramSaveInfoHandler (
  56   IN  EFI_HANDLE                    DispatchHandle,
  57   IN  EFI_SMM_SW_DISPATCH_CONTEXT   *DispatchContext
  58   )
  59 {
  60   ASSERT (DispatchContext != NULL);
  61   ASSERT (DispatchContext->SwSmiInputValue == SMM_FROM_SMBASE_DRIVER);
  62
  63   if (!mLocked && IoRead8 (mSmiDataRegister) == SMM_FROM_CPU_DRIVER_SAVE_INFO) {
  64       CopyMem (
  65         (VOID *)(UINTN)(PcdGetEx64 (&gEfiVLVTokenSpaceGuid, PcdCpuLockBoxDataAddress)),
  66         (VOID *)(UINTN)(PcdGetEx64 (&gEfiVLVTokenSpaceGuid, PcdCpuSmramCpuDataAddress)),
  67         (UINTN)(PcdGetEx64 (&gEfiVLVTokenSpaceGuid, PcdCpuLockBoxSize))
  68         );
  69   }
  70 }
  71
  72 /**
  73   Smm Ready To Lock event notification handler.
  74
  75   It sets a flag indicating that SMRAM has been locked.
  76
  77   @param[in] Protocol   Points to the protocol's unique identifier.
  78   @param[in] Interface  Points to the interface instance.
  79   @param[in] Handle     The handle on which the interface was installed.
  80
  81   @retval EFI_SUCCESS   Notification handler runs successfully.
  82  **/
  83 EFI_STATUS
  84 EFIAPI
  85 SmmReadyToLockEventNotify (
  86   IN CONST EFI_GUID  *Protocol,
  87   IN VOID            *Interface,
  88   IN EFI_HANDLE      Handle
  89   )
  90 {
  91   mLocked = TRUE;
  92   return EFI_SUCCESS;
  93 }
  94
  95 /**
  96   Entry point function of this driver.
  97
  98   @param[in] ImageHandle  The firmware allocated handle for the EFI image.
  99   @param[in] SystemTable  A pointer to the EFI System Table.
 100
 101   @retval EFI_SUCCESS     The entry point is executed successfully.
 102   @retval other           Some error occurs when executing this entry point.
 103 **/
 104 EFI_STATUS
 105 EFIAPI
 106 SmramSaveInfoHandlerSmmMain (
 107   IN EFI_HANDLE        ImageHandle,
 108   IN EFI_SYSTEM_TABLE  *SystemTable
 109   )
 110 {
 111   EFI_STATUS                    Status;
 112   EFI_SMM_SW_DISPATCH_PROTOCOL  *SmmSwDispatch;
 113   EFI_SMM_SW_DISPATCH_CONTEXT   SmmSwDispatchContext;
 114   EFI_HANDLE                    DispatchHandle;
 115   EFI_SMM_CONTROL_PROTOCOL      *SmmControl;
 116   EFI_SMM_CONTROL_REGISTER      SmmControlRegister;
 117   VOID                          *Registration;
 118
 119   //
 120   // Get SMI data register
 121   //
 122   Status = SystemTable->BootServices->LocateProtocol (
 123                                         &gEfiSmmControlProtocolGuid,
 124                                         NULL,
 125                                         (VOID **)&SmmControl
 126                                         );
 127   ASSERT_EFI_ERROR (Status);
 128   Status = SmmControl->GetRegisterInfo (SmmControl, &SmmControlRegister);
 129   ASSERT_EFI_ERROR (Status);
 130   mSmiDataRegister = SmmControlRegister.SmiDataRegister;
 131
 132   //
 133   // Register software SMI handler
 134   //
 135
 136   Status = SystemTable->BootServices->LocateProtocol (
 137                                         &gEfiSmmSwDispatchProtocolGuid,
 138                                         NULL,
 139                                         (VOID **)&SmmSwDispatch
 140                                         );
 141   ASSERT_EFI_ERROR (Status);
 142
 143   SmmSwDispatchContext.SwSmiInputValue = SMM_FROM_SMBASE_DRIVER;
 144   Status = SmmSwDispatch->Register (
 145                             SmmSwDispatch,
 146                             &SmramSaveInfoHandler,
 147                             &SmmSwDispatchContext,
 148                             &DispatchHandle
 149                             );
 150   ASSERT_EFI_ERROR (Status);
 151
 152   //
 153   // Register SMM Ready To Lock Protocol notification
 154   //
 155   Status = gSmst->SmmRegisterProtocolNotify (
 156                     &gEfiSmmReadyToLockProtocolGuid,
 157                     SmmReadyToLockEventNotify,
 158                     &Registration
 159                     );
 160   ASSERT_EFI_ERROR (Status);
 161
 162   return Status;
 163 }
 164