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 - 2014, Intel Corporation. All rights reserved.<BR>
   7
   8   This program and the accompanying materials are licensed and made available under
   9   the terms and conditions of the BSD License that accompanies this distribution.
  10   The full text of the license may be found at
  11   http://opensource.org/licenses/bsd-license.php.
  12
  13   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  14   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  15
  16
  17 **/
  18
  19 #include <PiSmm.h>
  20 #include <Library/DebugLib.h>
  21 #include <Library/UefiDriverEntryPoint.h>
  22 #include <Library/UefiRuntimeServicesTableLib.h>
  23 #include <Library/SmmServicesTableLib.h>
  24 #include <Library/BaseLib.h>
  25 #include <Library/BaseMemoryLib.h>
  26 #include <Library/IoLib.h>
  27 #include <Protocol/SmmSwDispatch.h>
  28 #include <Protocol/SmmReadyToLock.h>
  29 #include <Protocol/SmmControl.h>
  30
  31 #define SMM_FROM_SMBASE_DRIVER        0x55
  32 #define SMM_FROM_CPU_DRIVER_SAVE_INFO 0x81
  33
  34 #define EFI_SMRAM_CPU_NVS_HEADER_GUID \
  35   { \
  36     0x429501d9, 0xe447, 0x40f4, 0x86, 0x7b, 0x75, 0xc9, 0x3a, 0x1d, 0xb5, 0x4e \
  37   }
  38
  39 UINT8    mSmiDataRegister;
  40 BOOLEAN  mLocked = FALSE;
  41 EFI_GUID mSmramCpuNvsHeaderGuid = EFI_SMRAM_CPU_NVS_HEADER_GUID;
  42
  43 /**
  44   Dispatch function for a Software SMI handler.
  45
  46   @param  DispatchHandle        The handle of this dispatch function.
  47   @param  DispatchContext       The pointer to the dispatch function's context.
  48                                 The SwSmiInputValue field is filled in
  49                                 by the software dispatch driver prior to
  50                                 invoking this dispatch function.
  51                                 The dispatch function will only be called
  52                                 for input values for which it is registered.
  53
  54   @return None
  55
  56 **/
  57 VOID
  58 EFIAPI
  59 SmramSaveInfoHandler (
  60   IN  EFI_HANDLE                    DispatchHandle,
  61   IN  EFI_SMM_SW_DISPATCH_CONTEXT   *DispatchContext
  62   )
  63 {
  64   EFI_STATUS Status;
  65   UINT64     VarData[3];
  66   UINTN      VarSize;
  67
  68   ASSERT (DispatchContext != NULL);
  69   ASSERT (DispatchContext->SwSmiInputValue == SMM_FROM_SMBASE_DRIVER);
  70
  71   if (!mLocked && IoRead8 (mSmiDataRegister) == SMM_FROM_CPU_DRIVER_SAVE_INFO) {
  72     VarSize = sizeof (VarData);
  73     Status = gRT->GetVariable (
  74                     L"SmramCpuNvs",
  75                     &mSmramCpuNvsHeaderGuid,
  76                     NULL,
  77                     &VarSize,
  78                     VarData
  79                     );
  80     if (!EFI_ERROR (Status) && VarSize == sizeof (VarData)) {
  81       CopyMem (
  82         (VOID *)(UINTN)(VarData[0]),
  83         (VOID *)(UINTN)(VarData[1]),
  84         (UINTN)(VarData[2])
  85         );
  86     }
  87   }
  88 }
  89
  90 /**
  91   Smm Ready To Lock event notification handler.
  92
  93   It sets a flag indicating that SMRAM has been locked.
  94
  95   @param[in] Protocol   Points to the protocol's unique identifier.
  96   @param[in] Interface  Points to the interface instance.
  97   @param[in] Handle     The handle on which the interface was installed.
  98
  99   @retval EFI_SUCCESS   Notification handler runs successfully.
 100  **/
 101 EFI_STATUS
 102 EFIAPI
 103 SmmReadyToLockEventNotify (
 104   IN CONST EFI_GUID  *Protocol,
 105   IN VOID            *Interface,
 106   IN EFI_HANDLE      Handle
 107   )
 108 {
 109   mLocked = TRUE;
 110   return EFI_SUCCESS;
 111 }
 112
 113 /**
 114   Entry point function of this driver.
 115
 116   @param[in] ImageHandle  The firmware allocated handle for the EFI image.
 117   @param[in] SystemTable  A pointer to the EFI System Table.
 118
 119   @retval EFI_SUCCESS     The entry point is executed successfully.
 120   @retval other           Some error occurs when executing this entry point.
 121 **/
 122 EFI_STATUS
 123 EFIAPI
 124 SmramSaveInfoHandlerSmmMain (
 125   IN EFI_HANDLE        ImageHandle,
 126   IN EFI_SYSTEM_TABLE  *SystemTable
 127   )
 128 {
 129   EFI_STATUS                    Status;
 130   EFI_SMM_SW_DISPATCH_PROTOCOL  *SmmSwDispatch;
 131   EFI_SMM_SW_DISPATCH_CONTEXT   SmmSwDispatchContext;
 132   EFI_HANDLE                    DispatchHandle;
 133   EFI_SMM_CONTROL_PROTOCOL      *SmmControl;
 134   EFI_SMM_CONTROL_REGISTER      SmmControlRegister;
 135   VOID                          *Registration;
 136
 137   //
 138   // Get SMI data register
 139   //
 140   Status = SystemTable->BootServices->LocateProtocol (
 141                                         &gEfiSmmControlProtocolGuid,
 142                                         NULL,
 143                                         (VOID **)&SmmControl
 144                                         );
 145   ASSERT_EFI_ERROR (Status);
 146   Status = SmmControl->GetRegisterInfo (SmmControl, &SmmControlRegister);
 147   ASSERT_EFI_ERROR (Status);
 148   mSmiDataRegister = SmmControlRegister.SmiDataRegister;
 149
 150   //
 151   // Register software SMI handler
 152   //
 153
 154   Status = SystemTable->BootServices->LocateProtocol (
 155                                         &gEfiSmmSwDispatchProtocolGuid,
 156                                         NULL,
 157                                         (VOID **)&SmmSwDispatch
 158                                         );
 159   ASSERT_EFI_ERROR (Status);
 160
 161   SmmSwDispatchContext.SwSmiInputValue = SMM_FROM_SMBASE_DRIVER;
 162   Status = SmmSwDispatch->Register (
 163                             SmmSwDispatch,
 164                             &SmramSaveInfoHandler,
 165                             &SmmSwDispatchContext,
 166                             &DispatchHandle
 167                             );
 168   ASSERT_EFI_ERROR (Status);
 169
 170   //
 171   // Register SMM Ready To Lock Protocol notification
 172   //
 173   Status = gSmst->SmmRegisterProtocolNotify (
 174                     &gEfiSmmReadyToLockProtocolGuid,
 175                     SmmReadyToLockEventNotify,
 176                     &Registration
 177                     );
 178   ASSERT_EFI_ERROR (Status);
 179
 180   return Status;
 181 }
 182