alder_lake_bios/Intel/AlderLake/AlderLakePlatSamplePkg/Features/Me/MeUlvCheckDxe/MeUlvCheck.c

/**@file
  Perform Check for ULV mismatch (ULV PCH not paired with ULV/LV CPU)

@copyright
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  Unless otherwise agreed by Intel in writing, you may not remove or alter
  this notice or any other notice embedded in Materials by Intel or
  Intel's suppliers or licensors in any way.

  This file contains a 'Sample Driver' and is licensed as such under the terms
  of your license agreement with Intel or your vendor. This file may be modified
  by the user, subject to the additional terms of the license agreement.

@par Specification Reference:
**/

#include <Library/UefiBootServicesTableLib.h>
#include <Library/DebugLib.h>
#include <Library/BaseLib.h>
#include <Library/PciSegmentLib.h>
#include <Library/ConfigBlockLib.h>
#include <Library/MeFwStsLib.h>
#include <Protocol/MePolicy.h>
#include <Register/MeRegs.h>
#include <Register/HeciRegs.h>
#include <MeFwHob.h>
#include <MeState.h>

/**
  Perform End User messaging and halt booting because of ILLEGAL CPU-PCH configuration

  @param[in]  Event                 The event signaled.
  @param[in]  Context               The context passed in by the event notifier.
**/
VOID
EFIAPI
IllegalCpuForUlvPchHandler (
  IN  EFI_EVENT   Event,
  IN  VOID        *Context
  );

/**
  Entry point for the driver.
  Perform Check for ULV mismatch (ULV PCH not paired with ULV/LV CPU)
  In case of mismatch reported by FW, wait for ConsoleOut to initialize to warn user
  and stop booting process.

  @param[in]  ImageHandle  Image Handle.
  @param[in]  SystemTable  EFI System Table.

  @retval     EFI_SUCCESS  Function has completed successfully.
  @retval     Others       All other error conditions encountered result in an ASSERT.
**/
EFI_STATUS
EFIAPI
MeUlvCheckEntryPoint (
  IN EFI_HANDLE               ImageHandle,
  IN EFI_SYSTEM_TABLE         *SystemTable
  )
{
  EFI_EVENT            ConOutInitEvent;
  EFI_STATUS           Status;
  HECI_FWS_REGISTER    MeFirmwareStatus;
  UINT64               HeciBaseAddress;

  DEBUG ((DEBUG_INFO, "%a () start\n", __FUNCTION__));

  Status              = EFI_SUCCESS;
  ConOutInitEvent     = NULL;
  MeFirmwareStatus.ul = 0;
  HeciBaseAddress     = PCI_SEGMENT_LIB_ADDRESS (ME_SEGMENT, ME_BUS, ME_DEVICE_NUMBER, HECI_FUNCTION_NUMBER, 0);

  //
  // Find out whether HECI is disabled, if so, read it from Fwsts HOB.
  //
  if (PciSegmentRead32 (HeciBaseAddress + PCI_VENDOR_ID_OFFSET) == 0xFFFFFFFF) {
    MeFirmwareStatus = GetMeStatusFromFwstsHob ();
  } else {
    MeFirmwareStatus.ul = PciSegmentRead32 (HeciBaseAddress + R_ME_HFS);
  }

  //
  // Make sure HECI FWS register bit [3:0] CURRENT WORKING STATE is NOT equal value 8 (INVALID_CPU_PLUGGED_IN)
  // If INVALID_CPU_PLUGGED_IN determined it means that invalid CPU SKU is populated as determined by PCH HW SKU
  // BIOS must halt the platform and display appropriate message as follows:
  //
  if (MeFirmwareStatus.r.CurrentState == ME_STATE_INVALID_CPU) {
    DEBUG ((DEBUG_ERROR, "(ULV) An unsupported CPU/PCH configuration has been identified!\n"));
    //
    // Register callback for informing user and stopping the platform when CONOUT is initialized
    //
    Status = gBS->CreateEvent (
                    EVT_NOTIFY_SIGNAL,
                    TPL_CALLBACK,
                    IllegalCpuForUlvPchHandler,
                    NULL,
                    &ConOutInitEvent
                    );
    ASSERT_EFI_ERROR (Status);
  }

  return EFI_SUCCESS;
}

/**
  Perform End User messaging and halt booting because of ILLEGAL CPU-PCH configuration

  @param[in]  Event                 The event signaled.
  @param[in]  Context               The context passed in by the event notifier.
**/
VOID
EFIAPI
IllegalCpuForUlvPchHandler (
  IN  EFI_EVENT   Event,
  IN  VOID        *Context
  )
{
  ME_POLICY_PROTOCOL      *MePolicyInstance;
  EFI_STATUS              Status;
  ME_DXE_CONFIG           *MeDxeConfig;

  gBS->CloseEvent (Event);

  Status = gBS->LocateProtocol (&gDxeMePolicyGuid, NULL, (VOID **) &MePolicyInstance);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "(ULV) Failed to read ME Policy! Status = %r\n", Status));
    return;
  }

  Status = GetConfigBlock ((VOID *) MePolicyInstance, &gMeDxeConfigGuid, (VOID *) &MeDxeConfig);
  ASSERT_EFI_ERROR (Status);
  //
  // Indicate illegal configuration to End User and hang permanently
  //
  MeDxeConfig->MeReportError (MSG_ILLEGAL_CPU_PLUGGED_IN);
  CpuDeadLoop ();
}