/** @file
  This driver is responsible for the registration of child drivers
  and the abstraction of the PCH SMI sources.

Copyright (c) 2017 - 2019, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/
#include "PchSmm.h"
#include "PchSmmHelpers.h"
#include "PchSmmEspi.h"

//
// MODULE / GLOBAL DATA
//
// Module variables used by the both the main dispatcher and the source dispatchers
// Declared in PchSmm.h
//
GLOBAL_REMOVE_IF_UNREFERENCED UINT16                mAcpiBaseAddr;
GLOBAL_REMOVE_IF_UNREFERENCED UINT16                mTcoBaseAddr;
GLOBAL_REMOVE_IF_UNREFERENCED BOOLEAN               mReadyToLock;

GLOBAL_REMOVE_IF_UNREFERENCED PRIVATE_DATA          mPrivateData = {
  {
    NULL,
    NULL
  },                                    ///< CallbackDataBase linked list head
  NULL,                                 ///< EFI handle returned when calling InstallMultipleProtocolInterfaces
  NULL,                                 //
  {                                     ///< protocol arrays
    ///
    /// elements within the array
    ///
    {
      PROTOCOL_SIGNATURE,
      UsbType,
      &gEfiSmmUsbDispatch2ProtocolGuid,
      {{
        (PCH_SMM_GENERIC_REGISTER) PchSmmCoreRegister,
        (PCH_SMM_GENERIC_UNREGISTER) PchSmmCoreUnRegister,
      }}
    },
    {
      PROTOCOL_SIGNATURE,
      SxType,
      &gEfiSmmSxDispatch2ProtocolGuid,
      {{
        (PCH_SMM_GENERIC_REGISTER) PchSmmCoreRegister,
        (PCH_SMM_GENERIC_UNREGISTER) PchSmmCoreUnRegister
      }}
    },
    {
      PROTOCOL_SIGNATURE,
      SwType,
      &gEfiSmmSwDispatch2ProtocolGuid,
      {{
        (PCH_SMM_GENERIC_REGISTER) PchSmmCoreRegister,
        (PCH_SMM_GENERIC_UNREGISTER) PchSmmCoreUnRegister,
        (UINTN) MAXIMUM_SWI_VALUE
      }}
    },
    {
      PROTOCOL_SIGNATURE,
      GpiType,
      &gEfiSmmGpiDispatch2ProtocolGuid,
      {{
        (PCH_SMM_GENERIC_REGISTER) PchSmmCoreRegister,
        (PCH_SMM_GENERIC_UNREGISTER) PchSmmCoreUnRegister,
        (UINTN) V_PCH_GPIO_NUM_SUPPORTED_GPIS
      }}
    },
    {
      PROTOCOL_SIGNATURE,
      PowerButtonType,
      &gEfiSmmPowerButtonDispatch2ProtocolGuid,
      {{
        (PCH_SMM_GENERIC_REGISTER) PchSmmCoreRegister,
        (PCH_SMM_GENERIC_UNREGISTER) PchSmmCoreUnRegister
      }}
    },
    {
      PROTOCOL_SIGNATURE,
      PeriodicTimerType,
      &gEfiSmmPeriodicTimerDispatch2ProtocolGuid,
      {{
        (PCH_SMM_GENERIC_REGISTER) PchSmmCoreRegister,
        (PCH_SMM_GENERIC_UNREGISTER) PchSmmCoreUnRegister,
        (UINTN) PchSmmPeriodicTimerDispatchGetNextShorterInterval
      }}
    },
  }
};

GLOBAL_REMOVE_IF_UNREFERENCED CONTEXT_FUNCTIONS     mContextFunctions[PCH_SMM_PROTOCOL_TYPE_MAX] = {
  {
    NULL,
    NULL,
    NULL
  },
  {
    SxGetContext,
    SxCmpContext,
    NULL
  },
  {
    SwGetContext,
    SwCmpContext,
    SwGetCommBuffer
  },
  {
    NULL,
    NULL,
    NULL
  },
  {
    PowerButtonGetContext,
    PowerButtonCmpContext,
    NULL
  },
  {
    PeriodicTimerGetContext,
    PeriodicTimerCmpContext,
    PeriodicTimerGetCommBuffer
  },
};

//
// PROTOTYPES
//
// Functions use only in this file
//
EFI_STATUS
EFIAPI
PchSmmCoreDispatcher (
  IN       EFI_HANDLE         SmmImageHandle,
  IN CONST VOID               *PchSmmCore,     OPTIONAL
  IN OUT   VOID               *CommunicationBuffer,
  IN OUT   UINTN              *SourceSize
  );

//
// FUNCTIONS
//
/**
  SMM ready to lock notification event handler.

  @param  Protocol   Points to the protocol's unique identifier
  @param  Interface  Points to the interface instance
  @param  Handle     The handle on which the interface was installed

  @retval EFI_SUCCESS   SmmReadyToLockCallback runs successfully

**/
EFI_STATUS
EFIAPI
SmmReadyToLockCallback (
  IN CONST EFI_GUID                       *Protocol,
  IN VOID                                 *Interface,
  IN EFI_HANDLE                           Handle
  )
{
  mReadyToLock = TRUE;

  return EFI_SUCCESS;
}

/**
  <b>PchSmiDispatcher SMM Module Entry Point</b>\n
  - <b>Introduction</b>\n
    The PchSmiDispatcher module is an SMM driver which  provides SMI handler registration
    services for PCH generated SMIs.

  - <b>Details</b>\n
    This module provides SMI handler registration servicies for PCH SMIs.
    NOTE: All the register/unregister functions will be locked after SMM ready to boot signal event.
    Please make sure no handler is installed after that.

  - @pre
    - EFI_SMM_BASE2_PROTOCOL
      - Documented in the System Management Mode Core Interface Specification
    - EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
      - Documented in the UEFI 2.0 Specification and above
    - EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL
      - This is to ensure that PCI MMIO and IO resource has been prepared and available for this driver to allocate.
    - EFI_SMM_CPU_PROTOCOL

  - @result
    The PchSmiDispatcher driver produces:
    - EFI_SMM_USB_DISPATCH2_PROTOCOL
    - EFI_SMM_SX_DISPATCH2_PROTOCOL
    - EFI_SMM_SW_DISPATCH2_PROTOCOL
    - EFI_SMM_GPI_DISPATCH2_PROTOCOL
    - EFI_SMM_IO_TRAP_DISPATCH2_PROTOCOL
    - EFI_SMM_POWER_BUTTON_DISPATCH2_PROTOCOL
    - EFI_SMM_PERIODIC_TIMER_DISPATCH2_PROTOCOL
    - @link _PCH_SMM_IO_TRAP_CONTROL_PROTOCOL PCH_SMM_IO_TRAP_CONTROL_PROTOCOL @endlink
    - @link _PCH_PCIE_SMI_DISPATCH_PROTOCOL PCH_PCIE_SMI_DISPATCH_PROTOCOL @endlink
    - @link _PCH_TCO_SMI_DISPATCH_PROTOCOL PCH_TCO_SMI_DISPATCH_PROTOCOL @endlink
    - @link _PCH_ACPI_SMI_DISPATCH_PROTOCOL PCH_ACPI_SMI_DISPATCH_PROTOCOL @endlink
    - @link _PCH_GPIO_UNLOCK_SMI_DISPATCH_PROTOCOL PCH_GPIO_UNLOCK_SMI_DISPATCH_PROTOCOL @endlink
    - @link _PCH_SMI_DISPATCH_PROTOCOL PCH_SMI_DISPATCH_PROTOCOL @endlink
    - @link _PCH_ESPI_SMI_DISPATCH_PROTOCOL PCH_ESPI_SMI_DISPATCH_PROTOCOL @endlink

  @param[in] ImageHandle          Pointer to the loaded image protocol for this driver
  @param[in] SystemTable          Pointer to the EFI System Table

  @retval EFI_SUCCESS             PchSmmDispatcher Initialization completed.
**/
EFI_STATUS
EFIAPI
InitializePchSmmDispatcher (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  UINTN                LpcBaseAddress;
  EFI_STATUS           Status;
  VOID                 *SmmReadyToLockRegistration;

  ///
  /// Access ACPI Base Addresses Register
  ///
  LpcBaseAddress = MmPciBase (
                     DEFAULT_PCI_BUS_NUMBER_PCH,
                     PCI_DEVICE_NUMBER_PCH_LPC,
                     PCI_FUNCTION_NUMBER_PCH_LPC
                     );

  PchAcpiBaseGet (&mAcpiBaseAddr);
  ASSERT (mAcpiBaseAddr != 0);

  ///
  /// Access TCO Base Addresses Register
  ///
  PchTcoBaseGet (&mTcoBaseAddr);
  ASSERT (mTcoBaseAddr != 0);


  PchSwDispatchInit ();

  ///
  /// Register a callback function to handle subsequent SMIs.  This callback
  /// will be called by SmmCoreDispatcher.
  ///
  Status = gSmst->SmiHandlerRegister (PchSmmCoreDispatcher, NULL, &mPrivateData.SmiHandle);
  ASSERT_EFI_ERROR (Status);
  ///
  /// Initialize Callback DataBase
  ///
  InitializeListHead (&mPrivateData.CallbackDataBase);

  ///
  /// Enable SMIs on the PCH now that we have a callback
  ///
  PchSmmInitHardware ();

  //
  // Install and initialize all the needed protocols
  //
  PchSmmPublishDispatchProtocols ();
  InstallPchSmiDispatchProtocols ();
  InstallIoTrap (ImageHandle);
  InstallEspiSmi (ImageHandle);
  InstallPchSmmPeriodicTimerControlProtocol (mPrivateData.InstallMultProtHandle);

  //
  // Register EFI_SMM_READY_TO_LOCK_PROTOCOL_GUID notify function.
  //
  Status = gSmst->SmmRegisterProtocolNotify (
                    &gEfiSmmReadyToLockProtocolGuid,
                    SmmReadyToLockCallback,
                    &SmmReadyToLockRegistration
                    );
  ASSERT_EFI_ERROR (Status);

  return EFI_SUCCESS;
}

/**
  Check the Fed SwSmiInputValue to see if there is a duplicated one in the database

  @param[in] FedSwSmiInputValue   Fed SwSmiInputValue

  @retval EFI_SUCCESS             There is no duplicated SwSmiInputValue
  @retval EFI_INVALID_PARAMETER   There is a duplicated SwSmiInputValue
**/
EFI_STATUS
SmiInputValueDuplicateCheck (
  UINTN           FedSwSmiInputValue
  )
{

  DATABASE_RECORD *RecordInDb;
  LIST_ENTRY      *LinkInDb;

  LinkInDb = GetFirstNode (&mPrivateData.CallbackDataBase);
  while (!IsNull (&mPrivateData.CallbackDataBase, LinkInDb)) {
    RecordInDb = DATABASE_RECORD_FROM_LINK (LinkInDb);

    if (RecordInDb->ProtocolType == SwType) {
      if (RecordInDb->ChildContext.Sw.SwSmiInputValue == FedSwSmiInputValue) {
        return EFI_INVALID_PARAMETER;
      }
    }

    LinkInDb = GetNextNode (&mPrivateData.CallbackDataBase, &RecordInDb->Link);
  }

  return EFI_SUCCESS;
}

/**
  Register a child SMI dispatch function with a parent SMM driver.

  @param[in] This                 Pointer to the PCH_SMM_GENERIC_PROTOCOL instance.
  @param[in] DispatchFunction     Pointer to dispatch function to be invoked for this SMI source.
  @param[in] DispatchContext      Pointer to the dispatch function's context.
  @param[out] DispatchHandle      Handle of dispatch function, for when interfacing
                                  with the parent SMM driver, will be the address of linked
                                  list link in the call back record.

  @retval EFI_OUT_OF_RESOURCES    Insufficient resources to create database record
  @retval EFI_INVALID_PARAMETER   The input parameter is invalid
  @retval EFI_SUCCESS             The dispatch function has been successfully
                                  registered and the SMI source has been enabled.
**/
EFI_STATUS
EFIAPI
PchSmmCoreRegister (
  IN  PCH_SMM_GENERIC_PROTOCOL                          *This,
  IN  EFI_SMM_HANDLER_ENTRY_POINT2                      DispatchFunction,
  IN  PCH_SMM_CONTEXT                                   *DispatchContext,
  OUT EFI_HANDLE                                        *DispatchHandle
  )
{
  EFI_STATUS                  Status;
  DATABASE_RECORD             *Record;
  PCH_SMM_QUALIFIED_PROTOCOL  *Qualified;
  PCH_SMM_SOURCE_DESC         NullSourceDesc;
  UINTN                       Index;
  GPIO_PAD                    GpioPad;
  UINT8                       GpiSmiBitOffset;
  UINT32                      GpiSmiEnRegAddress;
  UINT32                      GpiSmiStsRegAddress;
  UINT32                      Data32Or;
  UINT32                      Data32And;
  UINTN                       ContextSize;

  //
  // Initialize NullSourceDesc
  //
  NullInitSourceDesc (&NullSourceDesc);

  //
  // Return access denied if the SmmReadyToLock event has been triggered
  //
  if (mReadyToLock == TRUE) {
    DEBUG ((DEBUG_ERROR, "Register is not allowed if the EndOfDxe event has been triggered! \n"));
    return EFI_ACCESS_DENIED;
  }

  Index     = 0;
  ///
  /// Create database record and add to database
  ///

  Status = gSmst->SmmAllocatePool (EfiRuntimeServicesData, sizeof (DATABASE_RECORD), (VOID **) &Record);
  if (EFI_ERROR (Status)) {
    ASSERT (FALSE);
    return EFI_OUT_OF_RESOURCES;
  }
  ZeroMem (Record, sizeof (DATABASE_RECORD));

  ///
  /// Gather information about the registration request
  ///
  Record->Callback          = DispatchFunction;

  Record->ChildContext      = *DispatchContext;

  Qualified                 = QUALIFIED_PROTOCOL_FROM_GENERIC (This);

  Record->ProtocolType      = Qualified->Type;

  Record->ContextFunctions  = mContextFunctions[Qualified->Type];
  ///
  /// Perform linked list housekeeping
  ///
  Record->Signature = DATABASE_RECORD_SIGNATURE;
  ContextSize = 0;

  switch (Qualified->Type) {
    ///
    /// By the end of this switch statement, we'll know the
    /// source description the child is registering for
    ///
    case UsbType:
      CopyMem (&Record->ChildContext, DispatchContext, sizeof (EFI_SMM_USB_REGISTER_CONTEXT));
      ///
      /// Check the validity of Context Type
      ///
      if ((Record->ChildContext.Usb.Type < UsbLegacy) || (Record->ChildContext.Usb.Type > UsbWake)) {
        goto Error;
      }

      MapUsbToSrcDesc (DispatchContext, &(Record->SrcDesc));
      Record->ClearSource = NULL;
      ContextSize = sizeof(Record->ChildContext.Usb);
      ///
      /// use default clear source function
      ///
      break;

    case SxType:
      CopyMem (&Record->ChildContext, DispatchContext, sizeof (EFI_SMM_SX_REGISTER_CONTEXT));
      ///
      /// Check the validity of Context Type and Phase
      ///
      if ((Record->ChildContext.Sx.Type < SxS0) ||
          (Record->ChildContext.Sx.Type >= EfiMaximumSleepType) ||
          (Record->ChildContext.Sx.Phase < SxEntry) ||
          (Record->ChildContext.Sx.Phase >= EfiMaximumPhase)
          ) {
        goto Error;
      }

      CopyMem ((VOID *) &(Record->SrcDesc), (VOID *) (&SX_SOURCE_DESC), sizeof (PCH_SMM_SOURCE_DESC));
      Record->ClearSource = NULL;
      ContextSize = sizeof(Record->ChildContext.Sx);
      ///
      /// use default clear source function
      ///
      break;

    case SwType:
      CopyMem (&Record->ChildContext, DispatchContext, sizeof (EFI_SMM_SW_REGISTER_CONTEXT));
      ///
      /// Check the validity of Context Value
      ///
      if (Record->ChildContext.Sw.SwSmiInputValue  == (UINTN) -1) {
        for (Index = 1; Index < MAXIMUM_SWI_VALUE; Index++) {
          if (!EFI_ERROR (SmiInputValueDuplicateCheck (Index))) {
            Record->ChildContext.Sw.SwSmiInputValue = Index;
            break;
          }
        }
        if (Record->ChildContext.Sw.SwSmiInputValue == (UINTN) -1) {
          goto Error;
        }
      }
      if (Record->ChildContext.Sw.SwSmiInputValue > MAXIMUM_SWI_VALUE) {
        goto Error;
      }

      if (EFI_ERROR (SmiInputValueDuplicateCheck (Record->ChildContext.Sw.SwSmiInputValue))) {
        goto Error;
      }
      CopyMem (DispatchContext, &Record->ChildContext, sizeof (EFI_SMM_SW_REGISTER_CONTEXT));

      CopyMem ((VOID *) &(Record->SrcDesc), (VOID *) (&SW_SOURCE_DESC), sizeof (PCH_SMM_SOURCE_DESC));
      Record->ClearSource = NULL;
      ContextSize = sizeof(Record->ChildContext.Sw);
      ///
      /// use default clear source function
      ///
      break;

    case GpiType:
      CopyMem (&Record->ChildContext, DispatchContext, sizeof (EFI_SMM_GPI_REGISTER_CONTEXT));

      Index = Record->ChildContext.Gpi.GpiNum;

      Status = GpioGetPadAndSmiRegs (
                 (UINT32) Index,
                 &GpioPad,
                 &GpiSmiBitOffset,
                 &GpiSmiEnRegAddress,
                 &GpiSmiStsRegAddress
                 );

      if (EFI_ERROR (Status)) {
        goto Error;
      }

      CopyMem (
        (VOID *) &(Record->SrcDesc),
        (VOID *) &(PCH_GPI_SOURCE_DESC_TEMPLATE),
        sizeof (PCH_SMM_SOURCE_DESC)
        );
      Record->SrcDesc.En[0].Reg.Data.raw = GpiSmiEnRegAddress;    // GPI SMI Enable register
      Record->SrcDesc.En[0].Bit = GpiSmiBitOffset;                // Bit position for selected pad
      Record->SrcDesc.Sts[0].Reg.Data.raw = GpiSmiStsRegAddress;  // GPI SMI Status register
      Record->SrcDesc.Sts[0].Bit = GpiSmiBitOffset;               // Bit position for selected pad
      Record->ClearSource = NULL;
      ContextSize = sizeof(Record->ChildContext.Gpi);
      ///
      /// use default clear source function
      ///
      ///
      /// Add GPI_SMI_EN programming into S3 boot script
      ///
      Data32Or  = (1u << GpiSmiBitOffset);
      Data32And = 0xFFFFFFFF;
      S3BootScriptSaveMemReadWrite (S3BootScriptWidthUint32, GpiSmiEnRegAddress, &Data32Or, &Data32And);

      break;

    case PowerButtonType:
      CopyMem (&Record->ChildContext, DispatchContext, sizeof (EFI_SMM_POWER_BUTTON_REGISTER_CONTEXT));
      ///
      /// Check the validity of Context Phase
      ///
      if ((Record->ChildContext.PowerButton.Phase < EfiPowerButtonEntry) ||
          (Record->ChildContext.PowerButton.Phase > EfiPowerButtonExit)
          ) {
        goto Error;
      }

      CopyMem ((VOID *) &(Record->SrcDesc), (VOID *) &POWER_BUTTON_SOURCE_DESC, sizeof (PCH_SMM_SOURCE_DESC));
      Record->ClearSource = NULL;
      ContextSize = sizeof(Record->ChildContext.PowerButton);
      ///
      /// use default clear source function
      ///
      break;

    case PeriodicTimerType:
      CopyMem (&Record->ChildContext, DispatchContext, sizeof (EFI_SMM_PERIODIC_TIMER_REGISTER_CONTEXT));
      ///
      /// Check the validity of timer value
      ///
      if (DispatchContext->PeriodicTimer.SmiTickInterval <= 0) {
        goto Error;
      }

      MapPeriodicTimerToSrcDesc (DispatchContext, &(Record->SrcDesc));
      Record->ClearSource = PchSmmPeriodicTimerClearSource;
      ContextSize = sizeof(Record->ChildContext.PeriodicTimer);
      break;

    default:
      goto Error;
      break;
  }

  if (CompareSources (&Record->SrcDesc, &NullSourceDesc)) {
    goto Error;
  }

  ///
  /// After ensuring the source of event is not null, we will insert the record into the database
  ///
  InsertTailList (&mPrivateData.CallbackDataBase, &Record->Link);

  if (Record->ClearSource == NULL) {
    ///
    /// Clear the SMI associated w/ the source using the default function
    ///
    PchSmmClearSource (&Record->SrcDesc);
  } else {
    ///
    /// This source requires special handling to clear
    ///
    Record->ClearSource (&Record->SrcDesc);
  }

  PchSmmEnableSource (&Record->SrcDesc);

  ///
  /// Child's handle will be the address linked list link in the record
  ///
  *DispatchHandle = (EFI_HANDLE) (&Record->Link);
  *DispatchContext = Record->ChildContext;

  SmiHandlerProfileRegisterHandler (Qualified->Guid, DispatchFunction, (UINTN)RETURN_ADDRESS (0), &Record->ChildContext, ContextSize);

  return EFI_SUCCESS;

Error:
  Status = gSmst->SmmFreePool (Record);
  ///
  /// DEBUG((DEBUG_ERROR,"Free pool status %d\n", Status ));
  ///
  return EFI_INVALID_PARAMETER;
}

/**
  Unregister a child SMI source dispatch function with a parent SMM driver.

  @param[in] This                 Pointer to the PCH_SMM_GENERIC_PROTOCOL instance.
  @param[in] DispatchHandle       Handle of dispatch function to deregister.

  @retval EFI_SUCCESS             The dispatch function has been successfully
                                  unregistered and the SMI source has been disabled
                                  if there are no other registered child dispatch
                                  functions for this SMI source.
  @retval EFI_INVALID_PARAMETER   Handle is invalid.
**/
EFI_STATUS
EFIAPI
PchSmmCoreUnRegister (
  IN PCH_SMM_GENERIC_PROTOCOL                           *This,
  IN EFI_HANDLE                                         *DispatchHandle
  )
{
  EFI_STATUS      Status;
  BOOLEAN         NeedClearEnable;
  UINTN           DescIndex;
  DATABASE_RECORD *RecordToDelete;
  DATABASE_RECORD *RecordInDb;
  LIST_ENTRY      *LinkInDb;
  PCH_SMM_QUALIFIED_PROTOCOL  *Qualified;

  if (DispatchHandle == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Return access denied if the SmmReadyToLock event has been triggered
  //
  if (mReadyToLock == TRUE) {
    DEBUG ((DEBUG_ERROR, "UnRegister is not allowed if the SmmReadyToLock event has been triggered! \n"));
    return EFI_ACCESS_DENIED;
  }

  RecordToDelete = DATABASE_RECORD_FROM_LINK (DispatchHandle);

  //
  // Take the entry out of the linked list
  //
  if (RecordToDelete->Link.ForwardLink == (LIST_ENTRY *) EFI_BAD_POINTER) {
    return EFI_INVALID_PARAMETER;
  }

  RemoveEntryList (&RecordToDelete->Link);

  //
  // Loop through all the souces in record linked list to see if any source enable is equal.
  // If any source enable is equal, we do not want to disable it.
  //
  for (DescIndex = 0; DescIndex < NUM_EN_BITS; ++DescIndex) {
    if (IS_BIT_DESC_NULL (RecordToDelete->SrcDesc.En[DescIndex])) {
      continue;
    }
    NeedClearEnable = TRUE;
    LinkInDb = GetFirstNode (&mPrivateData.CallbackDataBase);
    while (!IsNull (&mPrivateData.CallbackDataBase, LinkInDb)) {
      RecordInDb = DATABASE_RECORD_FROM_LINK (LinkInDb);
      if (IsBitEqualToAnySourceEn (&RecordToDelete->SrcDesc.En[DescIndex], &RecordInDb->SrcDesc)) {
        NeedClearEnable = FALSE;
        break;
      }
      LinkInDb = GetNextNode (&mPrivateData.CallbackDataBase, &RecordInDb->Link);
    }
    if (NeedClearEnable == FALSE) {
      continue;
    }
    WriteBitDesc (&RecordToDelete->SrcDesc.En[DescIndex], 0, FALSE);
  }

  if (This != NULL) {
    UINTN                       ContextSize;

    Qualified = QUALIFIED_PROTOCOL_FROM_GENERIC (This);
    switch (Qualified->Type) {
    case UsbType:
      ContextSize = sizeof(RecordToDelete->ChildContext.Usb);
      break;
    case SxType:
      ContextSize = sizeof(RecordToDelete->ChildContext.Sx);
      break;
    case SwType:
      ContextSize = sizeof(RecordToDelete->ChildContext.Sw);
      break;
    case GpiType:
      ContextSize = sizeof(RecordToDelete->ChildContext.Gpi);
      break;
    case PowerButtonType:
      ContextSize = sizeof(RecordToDelete->ChildContext.PowerButton);
      break;
    case PeriodicTimerType:
      ContextSize = sizeof(RecordToDelete->ChildContext.PeriodicTimer);
      break;
    default:
      ASSERT(FALSE);
      ContextSize = 0;
      break;
    }
    SmiHandlerProfileUnregisterHandler (Qualified->Guid, RecordToDelete->Callback, &RecordToDelete->ChildContext, ContextSize);
  } else {
    if (RecordToDelete->ProtocolGuid != NULL) {
      SmiHandlerProfileUnregisterHandler (RecordToDelete->ProtocolGuid, (EFI_SMM_HANDLER_ENTRY_POINT2)RecordToDelete->PchSmiCallback, &RecordToDelete->PchSmiType, sizeof(RecordToDelete->PchSmiType));
    }
  }

  Status = gSmst->SmmFreePool (RecordToDelete);
  if (EFI_ERROR (Status)) {
    ASSERT (FALSE);
    return Status;
  }
  return EFI_SUCCESS;
}

/**
  This function clears the pending SMI status before set EOS.
  NOTE: This only clears the pending SMI with known reason.
        Please do not clear unknown pending SMI status since that will hide potential issues.

  @param[in] SmiStsValue                SMI status
**/
static
VOID
ClearPendingSmiStatus (
  UINT32  SmiStsValue
  )
{
  //
  // Clear NewCentury status if it's not handled.
  //
  if (SmiStsValue & B_PCH_SMI_STS_TCO) {
    PchTcoClearNewCenturySts (NULL);
  }
  // Clear PWRBTNOR_STS if it's not handled.
  //
  if (IoRead16 (mAcpiBaseAddr + R_PCH_ACPI_PM1_STS) & B_PCH_ACPI_PM1_STS_PRBTNOR) {
    IoWrite16 (mAcpiBaseAddr + R_PCH_ACPI_PM1_STS, B_PCH_ACPI_PM1_STS_PRBTNOR);
  }
  //
  // Clear SWSMI if this is triggered by SmmControl.
  //
  if (SmiStsValue & B_PCH_SMI_STS_APM) {
    IoWrite32 (mAcpiBaseAddr + R_PCH_SMI_STS, B_PCH_SMI_STS_APM);
  }
}

/**
  The callback function to handle subsequent SMIs.  This callback will be called by SmmCoreDispatcher.

  @param[in] SmmImageHandle             Not used
  @param[in] PchSmmCore                 Not used
  @param[in, out] CommunicationBuffer   Not used
  @param[in, out] SourceSize            Not used

  @retval EFI_SUCCESS                   Function successfully completed
**/
EFI_STATUS
EFIAPI
PchSmmCoreDispatcher (
  IN       EFI_HANDLE         SmmImageHandle,
  IN CONST VOID               *PchSmmCore,
  IN OUT   VOID               *CommunicationBuffer,
  IN OUT   UINTN              *SourceSize
  )
{
  ///
  /// Used to prevent infinite loops
  ///
  UINTN               EscapeCount;

  BOOLEAN             ContextsMatch;
  BOOLEAN             EosSet;
  BOOLEAN             SxChildWasDispatched;

  DATABASE_RECORD     *RecordInDb;
  LIST_ENTRY          *LinkInDb;
  DATABASE_RECORD     *RecordToExhaust;
  LIST_ENTRY          *LinkToExhaust;

  PCH_SMM_CONTEXT     Context;
  VOID                *CommBuffer;
  UINTN               CommBufferSize;

  EFI_STATUS          Status;
  BOOLEAN             SciEn;
  UINT32              SmiEnValue;
  UINT32              SmiStsValue;
  UINT8               Port74Save;
  UINT8               Port76Save;

  PCH_SMM_SOURCE_DESC ActiveSource;

  //
  // Initialize ActiveSource
  //
  NullInitSourceDesc (&ActiveSource);

  EscapeCount           = 3;
  ContextsMatch         = FALSE;
  EosSet                = FALSE;
  SxChildWasDispatched  = FALSE;
  Status                = EFI_SUCCESS;

  //
  // Save IO index registers
  // @note: Save/Restore port 70h directly might break NMI_EN# setting,
  //       then save/restore 74h/76h instead.
  // @note: CF8 is not saved. Prefer method is to use MMIO instead of CF8
  //
  Port76Save = IoRead8 (R_PCH_RTC_EXT_INDEX_ALT);
  Port74Save = IoRead8 (R_PCH_RTC_INDEX_ALT);

  if (!IsListEmpty (&mPrivateData.CallbackDataBase)) {
    ///
    /// We have children registered w/ us -- continue
    ///
    while ((!EosSet) && (EscapeCount > 0)) {
      EscapeCount--;

      LinkInDb = GetFirstNode (&mPrivateData.CallbackDataBase);

      ///
      /// Cache SciEn, SmiEnValue and SmiStsValue to determine if source is active
      ///
      SciEn       = PchSmmGetSciEn ();
      SmiEnValue  = IoRead32 ((UINTN) (mAcpiBaseAddr + R_PCH_SMI_EN));
      SmiStsValue = IoRead32 ((UINTN) (mAcpiBaseAddr + R_PCH_SMI_STS));

      while (!IsNull (&mPrivateData.CallbackDataBase, LinkInDb)) {
        RecordInDb = DATABASE_RECORD_FROM_LINK (LinkInDb);

        ///
        /// look for the first active source
        ///
        if (!SourceIsActive (&RecordInDb->SrcDesc, SciEn, SmiEnValue, SmiStsValue)) {
          ///
          /// Didn't find the source yet, keep looking
          ///
          LinkInDb = GetNextNode (&mPrivateData.CallbackDataBase, &RecordInDb->Link);

          ///
          /// if it's the last one, try to clear EOS
          ///
          if (IsNull (&mPrivateData.CallbackDataBase, LinkInDb)) {
            //
            // Clear pending SMI status before EOS
            //
            ClearPendingSmiStatus (SmiStsValue);
            EosSet = PchSmmSetAndCheckEos ();
          }
        } else {
          ///
          /// We found a source. If this is a sleep type, we have to go to
          /// appropriate sleep state anyway.No matter there is sleep child or not
          ///
          if (RecordInDb->ProtocolType == SxType) {
            SxChildWasDispatched = TRUE;
          }
          ///
          /// "cache" the source description and don't query I/O anymore
          ///
          CopyMem ((VOID *) &ActiveSource, (VOID *) &(RecordInDb->SrcDesc), sizeof (PCH_SMM_SOURCE_DESC));
          LinkToExhaust = LinkInDb;

          ///
          /// exhaust the rest of the queue looking for the same source
          ///
          while (!IsNull (&mPrivateData.CallbackDataBase, LinkToExhaust)) {
            RecordToExhaust = DATABASE_RECORD_FROM_LINK (LinkToExhaust);
            ///
            /// RecordToExhaust->Link might be removed (unregistered) by Callback function, and then the
            /// system will hang in ASSERT() while calling GetNextNode().
            /// To prevent the issue, we need to get next record in DB here (before Callback function).
            ///
            LinkToExhaust = GetNextNode (&mPrivateData.CallbackDataBase, &RecordToExhaust->Link);

            if (CompareSources (&RecordToExhaust->SrcDesc, &ActiveSource)) {
              ///
              /// These source descriptions are equal, so this callback should be
              /// dispatched.
              ///
              if (RecordToExhaust->ContextFunctions.GetContext != NULL) {
                ///
                /// This child requires that we get a calling context from
                /// hardware and compare that context to the one supplied
                /// by the child.
                ///
                ASSERT (RecordToExhaust->ContextFunctions.CmpContext != NULL);

                ///
                /// Make sure contexts match before dispatching event to child
                ///
                RecordToExhaust->ContextFunctions.GetContext (RecordToExhaust, &Context);
                ContextsMatch = RecordToExhaust->ContextFunctions.CmpContext (&Context, &RecordToExhaust->ChildContext);

              } else {
                ///
                /// This child doesn't require any more calling context beyond what
                /// it supplied in registration.  Simply pass back what it gave us.
                ///
                Context       = RecordToExhaust->ChildContext;
                ContextsMatch = TRUE;
              }

              if (ContextsMatch) {
                if (RecordToExhaust->ProtocolType == PchSmiDispatchType) {
                  //
                  // For PCH SMI dispatch protocols
                  //
                  PchSmiTypeCallbackDispatcher (RecordToExhaust);
                } else {
                  //
                  // For EFI standard SMI dispatch protocols
                  //
                  if (RecordToExhaust->Callback != NULL) {
                    if (RecordToExhaust->ContextFunctions.GetCommBuffer != NULL) {
                      ///
                      /// This callback function needs CommBuffer and CommBufferSize.
                      /// Get those from child and then pass to callback function.
                      ///
                      RecordToExhaust->ContextFunctions.GetCommBuffer (RecordToExhaust, &CommBuffer, &CommBufferSize);
                    } else {
                      ///
                      /// Child doesn't support the CommBuffer and CommBufferSize.
                      /// Just pass NULL value to callback function.
                      ///
                      CommBuffer     = NULL;
                      CommBufferSize = 0;
                    }

                    PERF_START_EX (NULL, "SmmFunction", NULL, AsmReadTsc (), RecordToExhaust->ProtocolType);
                    RecordToExhaust->Callback ((EFI_HANDLE) & RecordToExhaust->Link, &Context, CommBuffer, &CommBufferSize);
                    PERF_END_EX (NULL, "SmmFunction", NULL, AsmReadTsc (), RecordToExhaust->ProtocolType);
                    if (RecordToExhaust->ProtocolType == SxType) {
                      SxChildWasDispatched = TRUE;
                    }
                  } else {
                    ASSERT (FALSE);
                  }
                }
              }
            }
          }

          if (RecordInDb->ClearSource == NULL) {
            ///
            /// Clear the SMI associated w/ the source using the default function
            ///
            PchSmmClearSource (&ActiveSource);
          } else {
            ///
            /// This source requires special handling to clear
            ///
            RecordInDb->ClearSource (&ActiveSource);
          }
          //
          // Clear pending SMI status before EOS
          //
          ClearPendingSmiStatus (SmiStsValue);
          ///
          /// Also, try to clear EOS
          ///
          EosSet = PchSmmSetAndCheckEos ();
          ///
          /// Queue is empty, reset the search
          ///
          break;
        }
      }
    }
  }
  ///
  /// If you arrive here, there are two possible reasons:
  /// (1) you've got problems with clearing the SMI status bits in the
  /// ACPI table.  If you don't properly clear the SMI bits, then you won't be able to set the
  /// EOS bit.  If this happens too many times, the loop exits.
  /// (2) there was a SMM communicate for callback messages that was received prior
  /// to this driver.
  /// If there is an asynchronous SMI that occurs while processing the Callback, let
  /// all of the drivers (including this one) have an opportunity to scan for the SMI
  /// and handle it.
  /// If not, we don't want to exit and have the foreground app. clear EOS without letting
  /// these other sources get serviced.
  ///
  /// This assert is not valid with CSM legacy solution because it generates software SMI
  /// to test for legacy USB support presence.
  /// This may not be illegal, so we cannot assert at this time.
  ///
  ///  ASSERT (EscapeCount > 0);
  ///
  if (SxChildWasDispatched) {
    ///
    /// A child of the SmmSxDispatch protocol was dispatched during this call;
    /// put the system to sleep.
    ///
    PchSmmSxGoToSleep ();
  }
  //
  // Restore IO index registers
  // @note: Save/Restore port 70h directly might break NMI_EN# setting,
  //       then save/restore 74h/76h instead.
  //
  IoWrite8 (R_PCH_RTC_EXT_INDEX_ALT, Port76Save);
  IoWrite8 (R_PCH_RTC_INDEX_ALT, Port74Save);

  return Status;
}