OvmfPkg/SmmAccess/SmmAccess2Dxe.c

   1 /** @file
   2
   3   A DXE_DRIVER providing SMRAM access by producing EFI_SMM_ACCESS2_PROTOCOL.
   4
   5   Q35 TSEG is expected to have been verified and set up by the SmmAccessPei
   6   driver.
   7
   8   Copyright (C) 2013, 2015, Red Hat, Inc.<BR>
   9   Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
  10
  11   This program and the accompanying materials are licensed and made available
  12   under the terms and conditions of the BSD License which accompanies this
  13   distribution. The full text of the license may be found at
  14   http://opensource.org/licenses/bsd-license.php
  15
  16   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
  17   WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  18
  19 **/
  20
  21 #include <Library/DebugLib.h>
  22 #include <Library/PcdLib.h>
  23 #include <Library/UefiBootServicesTableLib.h>
  24 #include <Protocol/SmmAccess2.h>
  25
  26 #include "SmramInternal.h"
  27
  28 /**
  29   Opens the SMRAM area to be accessible by a boot-service driver.
  30
  31   This function "opens" SMRAM so that it is visible while not inside of SMM.
  32   The function should return EFI_UNSUPPORTED if the hardware does not support
  33   hiding of SMRAM. The function should return EFI_DEVICE_ERROR if the SMRAM
  34   configuration is locked.
  35
  36   @param[in] This           The EFI_SMM_ACCESS2_PROTOCOL instance.
  37
  38   @retval EFI_SUCCESS       The operation was successful.
  39   @retval EFI_UNSUPPORTED   The system does not support opening and closing of
  40                             SMRAM.
  41   @retval EFI_DEVICE_ERROR  SMRAM cannot be opened, perhaps because it is
  42                             locked.
  43 **/
  44 STATIC
  45 EFI_STATUS
  46 EFIAPI
  47 SmmAccess2DxeOpen (
  48   IN EFI_SMM_ACCESS2_PROTOCOL  *This
  49   )
  50 {
  51   return SmramAccessOpen (&This->LockState, &This->OpenState);
  52 }
  53
  54 /**
  55   Inhibits access to the SMRAM.
  56
  57   This function "closes" SMRAM so that it is not visible while outside of SMM.
  58   The function should return EFI_UNSUPPORTED if the hardware does not support
  59   hiding of SMRAM.
  60
  61   @param[in] This           The EFI_SMM_ACCESS2_PROTOCOL instance.
  62
  63   @retval EFI_SUCCESS       The operation was successful.
  64   @retval EFI_UNSUPPORTED   The system does not support opening and closing of
  65                             SMRAM.
  66   @retval EFI_DEVICE_ERROR  SMRAM cannot be closed.
  67 **/
  68 STATIC
  69 EFI_STATUS
  70 EFIAPI
  71 SmmAccess2DxeClose (
  72   IN EFI_SMM_ACCESS2_PROTOCOL  *This
  73   )
  74 {
  75   return SmramAccessClose (&This->LockState, &This->OpenState);
  76 }
  77
  78 /**
  79   Inhibits access to the SMRAM.
  80
  81   This function prohibits access to the SMRAM region.  This function is usually
  82   implemented such that it is a write-once operation.
  83
  84   @param[in] This          The EFI_SMM_ACCESS2_PROTOCOL instance.
  85
  86   @retval EFI_SUCCESS      The device was successfully locked.
  87   @retval EFI_UNSUPPORTED  The system does not support locking of SMRAM.
  88 **/
  89 STATIC
  90 EFI_STATUS
  91 EFIAPI
  92 SmmAccess2DxeLock (
  93   IN EFI_SMM_ACCESS2_PROTOCOL  *This
  94   )
  95 {
  96   return SmramAccessLock (&This->LockState, &This->OpenState);
  97 }
  98
  99 /**
 100   Queries the memory controller for the possible regions that will support
 101   SMRAM.
 102
 103   @param[in]     This           The EFI_SMM_ACCESS2_PROTOCOL instance.
 104   @param[in,out] SmramMapSize   A pointer to the size, in bytes, of the
 105                                 SmramMemoryMap buffer.
 106   @param[in,out] SmramMap       A pointer to the buffer in which firmware
 107                                 places the current memory map.
 108
 109   @retval EFI_SUCCESS           The chipset supported the given resource.
 110   @retval EFI_BUFFER_TOO_SMALL  The SmramMap parameter was too small.  The
 111                                 current buffer size needed to hold the memory
 112                                 map is returned in SmramMapSize.
 113 **/
 114 STATIC
 115 EFI_STATUS
 116 EFIAPI
 117 SmmAccess2DxeGetCapabilities (
 118   IN CONST EFI_SMM_ACCESS2_PROTOCOL  *This,
 119   IN OUT UINTN                       *SmramMapSize,
 120   IN OUT EFI_SMRAM_DESCRIPTOR        *SmramMap
 121   )
 122 {
 123   return SmramAccessGetCapabilities (This->LockState, This->OpenState,
 124            SmramMapSize, SmramMap);
 125 }
 126
 127 //
 128 // LockState and OpenState will be filled in by the entry point.
 129 //
 130 STATIC EFI_SMM_ACCESS2_PROTOCOL mAccess2 = {
 131   &SmmAccess2DxeOpen,
 132   &SmmAccess2DxeClose,
 133   &SmmAccess2DxeLock,
 134   &SmmAccess2DxeGetCapabilities
 135 };
 136
 137 //
 138 // Entry point of this driver.
 139 //
 140 EFI_STATUS
 141 EFIAPI
 142 SmmAccess2DxeEntryPoint (
 143   IN EFI_HANDLE       ImageHandle,
 144   IN EFI_SYSTEM_TABLE *SystemTable
 145   )
 146 {
 147   //
 148   // This module should only be included if SMRAM support is required.
 149   //
 150   ASSERT (FeaturePcdGet (PcdSmmSmramRequire));
 151
 152   GetStates (&mAccess2.LockState, &mAccess2.OpenState);
 153   return gBS->InstallMultipleProtocolInterfaces (&ImageHandle,
 154                 &gEfiSmmAccess2ProtocolGuid, &mAccess2,
 155                 NULL);
 156 }