StandaloneMmPkg/Library/StandaloneMmMemLib/X86StandaloneMmMemLibInternal.c

/** @file
  Internal ARCH Specific file of MM memory check library.

  MM memory check library implementation. This library consumes MM_ACCESS_PROTOCOL
  to get MMRAM information. In order to use this library instance, the platform should produce
  all MMRAM range via MM_ACCESS_PROTOCOL, including the range for firmware (like MM Core
  and MM driver) and/or specific dedicated hardware.

  Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
  Copyright (c) 2016 - 2018, ARM Limited. All rights reserved.<BR>
  Copyright (c) Microsoft Corporation.

  SPDX-License-Identifier: BSD-2-Clause-Patent

**/
#include <PiMm.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/DebugLib.h>
#include <Library/HobLib.h>

#include <Guid/MmCoreData.h>
#include <Guid/MmramMemoryReserve.h>

//
// Maximum support address used to check input buffer
//
extern EFI_PHYSICAL_ADDRESS  mMmMemLibInternalMaximumSupportAddress;
extern EFI_MMRAM_DESCRIPTOR  *mMmMemLibInternalMmramRanges;
extern UINTN                 mMmMemLibInternalMmramCount;

/**
  Calculate and save the maximum support address.

**/
VOID
MmMemLibInternalCalculateMaximumSupportAddress (
  VOID
  )
{
  VOID    *Hob;
  UINT32  RegEax;
  UINT8   PhysicalAddressBits;

  //
  // Get physical address bits supported.
  //
  Hob = GetFirstHob (EFI_HOB_TYPE_CPU);
  if (Hob != NULL) {
    PhysicalAddressBits = ((EFI_HOB_CPU *)Hob)->SizeOfMemorySpace;
  } else {
    AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL);
    if (RegEax >= 0x80000008) {
      AsmCpuid (0x80000008, &RegEax, NULL, NULL, NULL);
      PhysicalAddressBits = (UINT8)RegEax;
    } else {
      PhysicalAddressBits = 36;
    }
  }

  //
  // IA-32e paging translates 48-bit linear addresses to 52-bit physical addresses.
  //
  ASSERT (PhysicalAddressBits <= 52);
  if (PhysicalAddressBits > 48) {
    PhysicalAddressBits = 48;
  }

  //
  // Save the maximum support address in one global variable
  //
  mMmMemLibInternalMaximumSupportAddress = (EFI_PHYSICAL_ADDRESS)(UINTN)(LShiftU64 (1, PhysicalAddressBits) - 1);
  DEBUG ((DEBUG_INFO, "mMmMemLibInternalMaximumSupportAddress = 0x%lx\n", mMmMemLibInternalMaximumSupportAddress));
}

/**
  Initialize cached Mmram Ranges from HOB.

  @retval EFI_UNSUPPORTED   The routine is unable to extract MMRAM information.
  @retval EFI_SUCCESS       MmRanges are populated successfully.

**/
EFI_STATUS
MmMemLibInternalPopulateMmramRanges (
  VOID
  )
{
  VOID                            *HobStart;
  EFI_HOB_GUID_TYPE               *GuidHob;
  MM_CORE_DATA_HOB_DATA           *DataInHob;
  MM_CORE_PRIVATE_DATA            *MmCorePrivateData;
  EFI_HOB_GUID_TYPE               *MmramRangesHob;
  EFI_MMRAM_HOB_DESCRIPTOR_BLOCK  *MmramRangesHobData;
  EFI_MMRAM_DESCRIPTOR            *MmramDescriptors;

  HobStart = GetHobList ();
  DEBUG ((DEBUG_INFO, "%a - 0x%x\n", __func__, HobStart));

  //
  // Extract MM Core Private context from the Hob. If absent search for
  // a Hob containing the MMRAM ranges
  //
  GuidHob = GetNextGuidHob (&gMmCoreDataHobGuid, HobStart);
  if (GuidHob == NULL) {
    MmramRangesHob = GetFirstGuidHob (&gEfiMmPeiMmramMemoryReserveGuid);
    if (MmramRangesHob == NULL) {
      return EFI_UNSUPPORTED;
    }

    MmramRangesHobData = GET_GUID_HOB_DATA (MmramRangesHob);
    if ((MmramRangesHobData == NULL) || (MmramRangesHobData->Descriptor == NULL)) {
      return EFI_UNSUPPORTED;
    }

    mMmMemLibInternalMmramCount = MmramRangesHobData->NumberOfMmReservedRegions;
    MmramDescriptors            = MmramRangesHobData->Descriptor;
  } else {
    DataInHob = GET_GUID_HOB_DATA (GuidHob);
    if (DataInHob == NULL) {
      return EFI_UNSUPPORTED;
    }

    MmCorePrivateData = (MM_CORE_PRIVATE_DATA *)(UINTN)DataInHob->Address;
    if ((MmCorePrivateData == NULL) || (MmCorePrivateData->MmramRanges == 0)) {
      return EFI_UNSUPPORTED;
    }

    mMmMemLibInternalMmramCount = (UINTN)MmCorePrivateData->MmramRangeCount;
    MmramDescriptors            = (EFI_MMRAM_DESCRIPTOR *)(UINTN)MmCorePrivateData->MmramRanges;
  }

  mMmMemLibInternalMmramRanges = AllocatePool (mMmMemLibInternalMmramCount * sizeof (EFI_MMRAM_DESCRIPTOR));
  if (mMmMemLibInternalMmramRanges) {
    CopyMem (
      mMmMemLibInternalMmramRanges,
      MmramDescriptors,
      mMmMemLibInternalMmramCount * sizeof (EFI_MMRAM_DESCRIPTOR)
      );
  }

  return EFI_SUCCESS;
}

/**
  Deinitialize cached Mmram Ranges.

**/
VOID
MmMemLibInternalFreeMmramRanges (
  VOID
  )
{
  if (mMmMemLibInternalMmramRanges != NULL) {
    FreePool (mMmMemLibInternalMmramRanges);
  }
}