path: root/SecurityPkg/Tcg/TcgSmm/TcgSmm.c

/** @file
  It updates TPM items in ACPI table and registers SMI callback
  functions for physical presence and ClearMemory.

Copyright (c) 2011, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials 
are licensed and made available under the terms and conditions of the BSD License 
which accompanies this distribution.  The full text of the license may be found at 
http://opensource.org/licenses/bsd-license.php

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/


#include <PiDxe.h>
#include <IndustryStandard/Acpi.h>
#include <Guid/PhysicalPresenceData.h>
#include <Guid/MemoryOverwriteControl.h>
#include <Protocol/SmmSwDispatch2.h>
#include <Protocol/AcpiTable.h>
#include <Protocol/SmmVariable.h>

#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/SmmServicesTableLib.h>
#include <Library/UefiDriverEntryPoint.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/DxeServicesLib.h>

//
// AML parsing definitions
//
#define AML_OPREGION_OP     0x80
#define AML_BYTE_PREFIX     0x0A
#define AML_DWORD_PREFIX    0x0C

#pragma pack(1)
typedef struct {
  UINT8                  SoftwareSmi;
  UINT32                 Parameter;
  UINT32                 Response;
  UINT32                 Request;
  UINT32                 LastRequest;
  UINT32                 ReturnCode;
} PHYSICAL_PRESENCE_NVS;

typedef struct {
  UINT8                  SoftwareSmi;
  UINT32                 Parameter;
  UINT32                 Request;
} MEMORY_CLEAR_NVS;

typedef struct {
  PHYSICAL_PRESENCE_NVS  PhysicalPresence;
  MEMORY_CLEAR_NVS       MemoryClear;
} TCG_NVS;

typedef struct {
  UINT8                  OpRegionOp;
  UINT32                 NameString;
  UINT8                  RegionSpace;
  UINT8                  DWordPrefix;
  UINT32                 RegionOffset;
  UINT8                  BytePrefix;
  UINT8                  RegionLen;
} AML_OP_REGION_32_8;
#pragma pack()

EFI_SMM_VARIABLE_PROTOCOL  *mSmmVariable;
TCG_NVS                    *mTcgNvs;

/**
  Software SMI callback for TPM physical presence which is called from ACPI method.

  @param[in]      DispatchHandle  The unique handle assigned to this handler by SmiHandlerRegister().
  @param[in]      Context         Points to an optional handler context which was specified when the
                                  handler was registered.
  @param[in, out] CommBuffer      A pointer to a collection of data in memory that will
                                  be conveyed from a non-SMM environment into an SMM environment.
  @param[in, out] CommBufferSize  The size of the CommBuffer.

  @retval EFI_SUCCESS             The interrupt was handled successfully.

**/
EFI_STATUS
EFIAPI
PhysicalPresenceCallback (
  IN EFI_HANDLE                  DispatchHandle,
  IN CONST VOID                  *Context,
  IN OUT VOID                    *CommBuffer,
  IN OUT UINTN                   *CommBufferSize
  )
{
  EFI_STATUS                     Status;
  UINTN                          DataSize;
  EFI_PHYSICAL_PRESENCE          PpData;
  UINT8                          Flags;
  BOOLEAN                        RequestConfirmed;

  //
  // Get the Physical Presence variable
  //
  DataSize = sizeof (EFI_PHYSICAL_PRESENCE);
  Status = mSmmVariable->SmmGetVariable (
                           PHYSICAL_PRESENCE_VARIABLE,
                           &gEfiPhysicalPresenceGuid,
                           NULL,
                           &DataSize,
                           &PpData
                           );
  if (EFI_ERROR (Status)) {
    return EFI_SUCCESS;
  }

  DEBUG ((EFI_D_INFO, "[TPM] PP callback, Parameter = %x\n", mTcgNvs->PhysicalPresence.Parameter));
  if (mTcgNvs->PhysicalPresence.Parameter == 5) {
    //
    // Return TPM Operation Response to OS Environment
    //
    mTcgNvs->PhysicalPresence.LastRequest = PpData.LastPPRequest;
    mTcgNvs->PhysicalPresence.Response    = PpData.PPResponse;

  } else if ((mTcgNvs->PhysicalPresence.Parameter == 2) || (mTcgNvs->PhysicalPresence.Parameter == 7)) {
    //
    // Submit TPM Operation Request to Pre-OS Environment
    //

    if (mTcgNvs->PhysicalPresence.Request == SET_OPERATOR_AUTH) {
      //
      // This command requires UI to prompt user for Auth data, NOT implemented.
      //
      mTcgNvs->PhysicalPresence.ReturnCode = 1;
      return EFI_SUCCESS;
    }

    if (PpData.PPRequest != mTcgNvs->PhysicalPresence.Request) {
      PpData.PPRequest = (UINT8) mTcgNvs->PhysicalPresence.Request;
      DataSize = sizeof (EFI_PHYSICAL_PRESENCE);
      Status = mSmmVariable->SmmSetVariable (
                               PHYSICAL_PRESENCE_VARIABLE,
                               &gEfiPhysicalPresenceGuid,
                               EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
                               DataSize,
                               &PpData
                               );
    }

    if (EFI_ERROR (Status)) { 
      //
      // General failure.
      //
      mTcgNvs->PhysicalPresence.ReturnCode = 2;
      return EFI_SUCCESS;
    }
    mTcgNvs->PhysicalPresence.ReturnCode = 0;
  } else if (mTcgNvs->PhysicalPresence.Parameter == 8) {
    // 
    // Get User Confirmation Status for Operation
    //
    Flags = PpData.Flags;  
    RequestConfirmed = FALSE;

    switch (mTcgNvs->PhysicalPresence.Request) {
      case ENABLE:
      case DISABLE:
      case ACTIVATE:
      case DEACTIVATE:
      case ENABLE_ACTIVATE:
      case DEACTIVATE_DISABLE:
      case SET_OWNER_INSTALL_TRUE:
      case SET_OWNER_INSTALL_FALSE:
      case ENABLE_ACTIVATE_OWNER_TRUE:
      case DEACTIVATE_DISABLE_OWNER_FALSE:
        if ((Flags & FLAG_NO_PPI_PROVISION) != 0) {
          RequestConfirmed = TRUE;
        }
        break;

      case CLEAR:
      case ENABLE_ACTIVATE_CLEAR:
        if ((Flags & FLAG_NO_PPI_CLEAR) != 0) {
          RequestConfirmed = TRUE;
        }
        break;

      case DEFERRED_PP_UNOWNERED_FIELD_UPGRADE:
        if ((Flags & FLAG_NO_PPI_MAINTENANCE) != 0) {
          RequestConfirmed = TRUE;
        }
        break;

      case ENABLE_ACTIVATE_CLEAR_ENABLE_ACTIVATE:
      case CLEAR_ENABLE_ACTIVATE:
        if ((Flags & FLAG_NO_PPI_CLEAR) != 0 && (Flags & FLAG_NO_PPI_PROVISION) != 0) {
          RequestConfirmed = TRUE;
        }
        break;  

      case SET_NO_PPI_PROVISION_FALSE:
      case SET_NO_PPI_CLEAR_FALSE:
      case SET_NO_PPI_MAINTENANCE_FALSE:
      case NO_ACTION:
        RequestConfirmed = TRUE;
        break;

      case SET_OPERATOR_AUTH:
        //
        // This command requires UI to prompt user for Auth data
        // Here it is NOT implemented
        //
        mTcgNvs->PhysicalPresence.ReturnCode = 0; 
        return EFI_SUCCESS;
    }

    if (RequestConfirmed) {
      //
      // Allowed and physically present user not required 
      //
      mTcgNvs->PhysicalPresence.ReturnCode = 4;
    } else {
      //
      // Allowed and physically present user required 
      //
      mTcgNvs->PhysicalPresence.ReturnCode = 3;
    }    
  } 

  return EFI_SUCCESS;
}


/**
  Software SMI callback for MemoryClear which is called from ACPI method.

  @param[in]      DispatchHandle  The unique handle assigned to this handler by SmiHandlerRegister().
  @param[in]      Context         Points to an optional handler context which was specified when the
                                  handler was registered.
  @param[in, out] CommBuffer      A pointer to a collection of data in memory that will
                                  be conveyed from a non-SMM environment into an SMM environment.
  @param[in, out] CommBufferSize  The size of the CommBuffer.

  @retval EFI_SUCCESS             The interrupt was handled successfully.

**/
EFI_STATUS
EFIAPI
MemoryClearCallback (
  IN EFI_HANDLE                  DispatchHandle,
  IN CONST VOID                  *Context,
  IN OUT VOID                    *CommBuffer,
  IN OUT UINTN                   *CommBufferSize
  )
{
  EFI_STATUS                     Status;
  UINTN                          DataSize;
  UINT8                          MorControl;

  if (mTcgNvs->MemoryClear.Parameter == 1) {
    //
    // Called from ACPI _DSM method, save the MOR data to variable.
    //
    MorControl = (UINT8) mTcgNvs->MemoryClear.Request;
  } else if (mTcgNvs->MemoryClear.Parameter == 2) {
    //
    // Called from ACPI _PTS method, setup ClearMemory flags if needed.
    //
    DataSize = sizeof (UINT8);
    Status = mSmmVariable->SmmGetVariable (
                             MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME,
                             &gEfiMemoryOverwriteControlDataGuid,
                             NULL,
                             &DataSize,
                             &MorControl
                             );
    if (EFI_ERROR (Status)) {
      ASSERT (Status == EFI_NOT_FOUND);
      return EFI_SUCCESS;
    }

    if (MOR_CLEAR_MEMORY_VALUE (MorControl) == 0x0) {
      return EFI_SUCCESS;
    }
    MorControl &= ~MOR_CLEAR_MEMORY_BIT_MASK;
  }

  DataSize = sizeof (UINT8);
  Status = mSmmVariable->SmmSetVariable (
                           MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME,
                           &gEfiMemoryOverwriteControlDataGuid,
                           EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
                           DataSize,
                           &MorControl
                           );
  ASSERT_EFI_ERROR (Status);

  return EFI_SUCCESS;
}

/**
  Find the operation region in TCG ACPI table by given Name and Size,
  and initialize it if the region is found.

  @param[in, out] Table          The TPM item in ACPI table.
  @param[in]      Name           The name string to find in TPM table.
  @param[in]      Size           The size of the region to find.

  @return                        The allocated address for the found region.

**/
VOID *
AssignOpRegion (
  EFI_ACPI_DESCRIPTION_HEADER    *Table,
  UINT32                         Name,
  UINT16                         Size
  )
{
  EFI_STATUS                     Status;
  AML_OP_REGION_32_8             *OpRegion;
  EFI_PHYSICAL_ADDRESS           MemoryAddress;

  MemoryAddress = SIZE_4GB - 1;

  //
  // Patch some pointers for the ASL code before loading the SSDT.
  //
  for (OpRegion  = (AML_OP_REGION_32_8 *) (Table + 1);
       OpRegion <= (AML_OP_REGION_32_8 *) ((UINT8 *) Table + Table->Length);
       OpRegion  = (AML_OP_REGION_32_8 *) ((UINT8 *) OpRegion + 1)) {
    if ((OpRegion->OpRegionOp  == AML_OPREGION_OP) && 
        (OpRegion->NameString  == Name) &&
        (OpRegion->RegionLen   == Size) &&
        (OpRegion->DWordPrefix == AML_DWORD_PREFIX) &&
        (OpRegion->BytePrefix  == AML_BYTE_PREFIX)) {

      Status = gBS->AllocatePages(AllocateMaxAddress, EfiACPIMemoryNVS, EFI_SIZE_TO_PAGES (Size), &MemoryAddress);
      ASSERT_EFI_ERROR (Status);
      ZeroMem ((VOID *)(UINTN)MemoryAddress, Size);
      OpRegion->RegionOffset = (UINT32) (UINTN) MemoryAddress;
      break;
    }
  }

  return (VOID *) (UINTN) MemoryAddress;
}

/**
  Initialize and publish TPM items in ACPI table.

  @retval   EFI_SUCCESS     The TCG ACPI table is published successfully.
  @retval   Others          The TCG ACPI table is not published.

**/
EFI_STATUS
PublishAcpiTable (
  VOID
  )
{
  EFI_STATUS                     Status;
  EFI_ACPI_TABLE_PROTOCOL        *AcpiTable;
  UINTN                          TableKey;
  EFI_ACPI_DESCRIPTION_HEADER    *Table;
  UINTN                          TableSize;

  Status = GetSectionFromFv (
             &gEfiCallerIdGuid,
             EFI_SECTION_RAW,
             0,
             (VOID **) &Table,
             &TableSize
             );
  ASSERT_EFI_ERROR (Status);

  ASSERT (Table->OemTableId == SIGNATURE_64 ('T', 'c', 'g', 'T', 'a', 'b', 'l', 'e'));
  mTcgNvs = AssignOpRegion (Table, SIGNATURE_32 ('T', 'N', 'V', 'S'), (UINT16) sizeof (TCG_NVS));
  ASSERT (mTcgNvs != NULL);

  //
  // Publish the TPM ACPI table
  //
  Status = gBS->LocateProtocol (&gEfiAcpiTableProtocolGuid, NULL, (VOID **) &AcpiTable);
  ASSERT_EFI_ERROR (Status);

  TableKey = 0;
  Status = AcpiTable->InstallAcpiTable (
                        AcpiTable,
                        Table,
                        TableSize,
                        &TableKey
                        );
  ASSERT_EFI_ERROR (Status);

  return Status;
}

/**
  The driver's entry point.

  It install callbacks for TPM physical presence and MemoryClear, and locate 
  SMM variable to be used in the callback function.

  @param[in] ImageHandle  The firmware allocated handle for the EFI image.  
  @param[in] SystemTable  A pointer to the EFI System Table.
  
  @retval EFI_SUCCESS     The entry point is executed successfully.
  @retval Others          Some error occurs when executing this entry point.

**/
EFI_STATUS
EFIAPI
InitializeTcgSmm (
  IN EFI_HANDLE                  ImageHandle,
  IN EFI_SYSTEM_TABLE            *SystemTable
  )
{
  EFI_STATUS                     Status;
  EFI_SMM_SW_DISPATCH2_PROTOCOL  *SwDispatch;
  EFI_SMM_SW_REGISTER_CONTEXT    SwContext;
  EFI_HANDLE                     SwHandle;

  Status = PublishAcpiTable ();
  ASSERT_EFI_ERROR (Status);

  //
  // Get the Sw dispatch protocol and register SMI callback functions.
  //
  Status = gSmst->SmmLocateProtocol (&gEfiSmmSwDispatch2ProtocolGuid, NULL, (VOID**)&SwDispatch);
  ASSERT_EFI_ERROR (Status);
  SwContext.SwSmiInputValue = (UINTN) -1;
  Status = SwDispatch->Register (SwDispatch, PhysicalPresenceCallback, &SwContext, &SwHandle);
  ASSERT_EFI_ERROR (Status);
  if (EFI_ERROR (Status)) {
    return Status;
  }
  mTcgNvs->PhysicalPresence.SoftwareSmi = (UINT8) SwContext.SwSmiInputValue;

  SwContext.SwSmiInputValue = (UINTN) -1;
  Status = SwDispatch->Register (SwDispatch, MemoryClearCallback, &SwContext, &SwHandle);
  ASSERT_EFI_ERROR (Status);
  if (EFI_ERROR (Status)) {
    return Status;
  }
  mTcgNvs->MemoryClear.SoftwareSmi = (UINT8) SwContext.SwSmiInputValue;
  
  //
  // Locate SmmVariableProtocol.
  //
  Status = gSmst->SmmLocateProtocol (&gEfiSmmVariableProtocolGuid, NULL, (VOID**)&mSmmVariable);
  ASSERT_EFI_ERROR (Status);

  return EFI_SUCCESS;
}