Re: [edk2-platforms:PATCH] Intel/IntelSiliconPkg Implement SmmAccess in IntelSiliconPkg

["Ni, Ray" <ray.ni@intel.com>]

Marc,
the dependency may be not ideal right now. but recommendation is not changed😊

> -----Original Message-----
> From: Chen, Marc W
> Sent: Friday, August 23, 2019 11:26 PM
> To: Ni, Ray <ray.ni@intel.com>; Chaganty, Rangasai V <rangasai.v.chaganty@intel.com>; devel@edk2.groups.io
> Subject: RE: [edk2-platforms:PATCH] Intel/IntelSiliconPkg Implement SmmAccess in IntelSiliconPkg
> 
> Thanks Ray and Sai for reviewing, please see my below reply for your questions.
> 
> 1. The reason why I put the Library folder in Feature/SmmAccess folder is because I saw Feature/Capsule also doing it this way,
> so I thought we want to put all related implementation in the same feature folder including library, please let me know if you
> want me to move the PeiSmmAccessLib to root Library folder.
> 
> 2. I saw that Vtd also depend on MdeModulePkg, so I thought IntelSiliconPkg is allowed to use MdeModulePkg, and SmmAccess
> code need SmmAccess.h, which is in MdeModulePkg, even we can change to use MmAccess.h from MdePkg now, but I thought
> the SMM is belong to x86 silicon, so use SmmAccess.h is better than MmAccess.h, let me know if you prefer to use MmAccess,
> then I'll modify the Patch to use that.
> 
> Thanks,
> Marc
> 
> > -----Original Message-----
> > From: Ni, Ray
> > Sent: Saturday, August 24, 2019 5:03 AM
> > To: Chaganty, Rangasai V <rangasai.v.chaganty@intel.com>; Chen, Marc W
> > <marc.w.chen@intel.com>; devel@edk2.groups.io
> > Subject: RE: [edk2-platforms:PATCH] Intel/IntelSiliconPkg Implement
> > SmmAccess in IntelSiliconPkg
> >
> > It's not recommended to make IntelSiliconPkg depend on MdeModulePkg.
> >
> > > -----Original Message-----
> > > From: Chaganty, Rangasai V
> > > Sent: Friday, August 23, 2019 11:34 AM
> > > To: Chen, Marc W <marc.w.chen@intel.com>; devel@edk2.groups.io
> > > Cc: Ni, Ray <ray.ni@intel.com>
> > > Subject: RE: [edk2-platforms:PATCH] Intel/IntelSiliconPkg Implement
> > SmmAccess in IntelSiliconPkg
> > >
> > > May I know the reason to implement the SmmAccessLib instance under
> > \Feature folder?
> > > Can we move it under IntelSiliconPkg\Library (We need to create a library
> > folder in the root) and keep just the module in the
> > > \Feature folder?
> > >
> > > I've noticed there is a dependency on MdeModulePkg with this change.
> > > Could you provide the reason to have such dependency as part of this
> > change?
> > >
> > > Thanks,
> > > Sai
> > >
> > > -----Original Message-----
> > > From: Chen, Marc W
> > > Sent: Friday, August 23, 2019 3:28 AM
> > > To: devel@edk2.groups.io
> > > Cc: Chen, Marc W <marc.w.chen@intel.com>; Ni, Ray <ray.ni@intel.com>;
> > Chaganty, Rangasai V
> > > <rangasai.v.chaganty@intel.com>
> > > Subject: [edk2-platforms:PATCH] Intel/IntelSiliconPkg Implement
> > SmmAccess in IntelSiliconPkg
> > >
> > > REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2121
> > >
> > > Implement SmmAccess for PEI and DXE phase in IntelSiliconPkg
> > >
> > > Signed-off-by: Marc Chen <marc.w.chen@intel.com>
> > > Cc: Ray Ni <ray.ni@intel.com>
> > > Cc: Rangasai V Chaganty <rangasai.v.chaganty@intel.com>
> > > ---
> > >  .../Library/PeiSmmAccessLib/PeiSmmAccessLib.c      | 343
> > +++++++++++++++++++++
> > >  .../Library/PeiSmmAccessLib/PeiSmmAccessLib.inf    |  42 +++
> > >  .../Feature/SmmAccess/SmmAccessDxe/SmmAccess.inf   |  47 +++
> > >  .../SmmAccess/SmmAccessDxe/SmmAccessDriver.c       | 267
> > ++++++++++++++++
> > >  .../SmmAccess/SmmAccessDxe/SmmAccessDriver.h       | 160 ++++++++++
> > >  .../IntelSiliconPkg/Include/Library/SmmAccessLib.h |  32 ++
> > >  6 files changed, 891 insertions(+)
> > >  create mode 100644
> > Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/Library/PeiSmmAccessLib/
> > PeiSmmAccessLib.c
> > >  create mode 100644
> > Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/Library/PeiSmmAccessLib/
> > PeiSmmAccessLib.inf
> > >  create mode 100644
> > Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/SmmAccessDxe/SmmAcce
> > ss.inf
> > >  create mode 100644
> > Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/SmmAccessDxe/SmmAcce
> > ssDriver.c
> > >  create mode 100644
> > Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/SmmAccessDxe/SmmAcce
> > ssDriver.h
> > >  create mode 100644
> > Silicon/Intel/IntelSiliconPkg/Include/Library/SmmAccessLib.h
> > >
> > > diff --git
> > a/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/Library/PeiSmmAccessLi
> > b/PeiSmmAccessLib.c
> > >
> > b/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/Library/PeiSmmAccessLi
> > b/PeiSmmAccessLib.c
> > > new file mode 100644
> > > index 0000000000..88eb217d2a
> > > --- /dev/null
> > > +++
> > b/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/Library/PeiSmmAcce
> > > +++ ssLib/PeiSmmAccessLib.c
> > > @@ -0,0 +1,343 @@
> > > +/** @file
> > > +  This is to publish the SMM Access Ppi instance.
> > > +
> > > +  Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
> > > +  SPDX-License-Identifier: BSD-2-Clause-Patent
> > > +
> > > +**/
> > > +#include <Library/BaseMemoryLib.h>
> > > +#include <Library/DebugLib.h>
> > > +#include <Library/MemoryAllocationLib.h> #include
> > > +<Library/PciSegmentLib.h> #include <Library/PeiServicesLib.h> #include
> > > +<Library/HobLib.h> #include <Uefi/UefiBaseType.h> #include
> > > +<Guid/SmramMemoryReserve.h>
> > > +
> > > +#include <Ppi/SmmAccess.h>
> > > +#include <IndustryStandard/Pci22.h>
> > > +
> > > +#define SMM_ACCESS_PRIVATE_DATA_SIGNATURE SIGNATURE_32 ('4',
> > '5', 's',
> > > +'a')
> > > +
> > > +///
> > > +/// Private data
> > > +///
> > > +typedef struct {
> > > +  UINTN                 Signature;
> > > +  EFI_HANDLE            Handle;
> > > +  PEI_SMM_ACCESS_PPI    SmmAccess;
> > > +  //
> > > +  // Local Data for SMM Access interface goes here
> > > +  //
> > > +  UINTN                 NumberRegions;
> > > +  EFI_SMRAM_DESCRIPTOR  *SmramDesc;
> > > +} SMM_ACCESS_PRIVATE_DATA;
> > > +
> > > +#define SMM_ACCESS_PRIVATE_DATA_FROM_THIS(a) \
> > > +        CR (a, \
> > > +          SMM_ACCESS_PRIVATE_DATA, \
> > > +          SmmAccess, \
> > > +          SMM_ACCESS_PRIVATE_DATA_SIGNATURE \
> > > +      )
> > > +
> > > +/**
> > > +  This routine accepts a request to "open" a region of SMRAM.  The
> > > +  region could be legacy ABSEG, HSEG, or TSEG near top of physical
> > memory.
> > > +  The use of "open" means that the memory is visible from all PEIM
> > > +  and SMM agents.
> > > +
> > > +  @param[in] This             -  Pointer to the SMM Access Interface.
> > > +  @param[in] DescriptorIndex  -  Region of SMRAM to Open.
> > > +  @param[in] PeiServices      -  General purpose services available to every
> > PEIM.
> > > +
> > > +  @retval EFI_SUCCESS            -  The region was successfully opened.
> > > +  @retval EFI_DEVICE_ERROR       -  The region could not be opened
> > because locked by
> > > +                                    chipset.
> > > +  @retval EFI_INVALID_PARAMETER  -  The descriptor index was out of
> > bounds.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +Open (
> > > +  IN EFI_PEI_SERVICES           **PeiServices,
> > > +  IN PEI_SMM_ACCESS_PPI         *This,
> > > +  IN UINTN                      DescriptorIndex
> > > +  )
> > > +{
> > > +  SMM_ACCESS_PRIVATE_DATA *SmmAccess;
> > > +
> > > +  SmmAccess = SMM_ACCESS_PRIVATE_DATA_FROM_THIS (This);  if
> > > + (DescriptorIndex >= SmmAccess->NumberRegions) {
> > > +    DEBUG ((DEBUG_WARN, "SMRAM region out of range\n"));
> > > +
> > > +    return EFI_INVALID_PARAMETER;
> > > +  } else if (SmmAccess->SmramDesc[DescriptorIndex].RegionState &
> > EFI_SMRAM_LOCKED) {
> > > +    //
> > > +    // Cannot open a "locked" region
> > > +    //
> > > +    DEBUG ((DEBUG_WARN, "Cannot open a locked SMRAM region\n"));
> > > +
> > > +    return EFI_DEVICE_ERROR;
> > > +  }
> > > +
> > > +  SmmAccess->SmramDesc[DescriptorIndex].RegionState &= (UINT64)
> > > +~(EFI_SMRAM_CLOSED | EFI_ALLOCATED);
> > > +  SmmAccess->SmramDesc[DescriptorIndex].RegionState |= (UINT64)
> > > +EFI_SMRAM_OPEN;
> > > +  SmmAccess->SmmAccess.OpenState = TRUE;
> > > +  return EFI_SUCCESS;
> > > +}
> > > +
> > > +/**
> > > +  This routine accepts a request to "close" a region of SMRAM.  This is
> > > +valid for
> > > +  compatible SMRAM region.
> > > +
> > > +  @param[in] PeiServices      -  General purpose services available to every
> > PEIM.
> > > +  @param[in] This             -  Pointer to the SMM Access Interface.
> > > +  @param[in] DescriptorIndex  -  Region of SMRAM to Close.
> > > +
> > > +  @retval EFI_SUCCESS            -  The region was successfully closed.
> > > +  @retval EFI_DEVICE_ERROR       -  The region could not be closed because
> > locked by
> > > +                                    chipset.
> > > +  @retval EFI_INVALID_PARAMETER  -  The descriptor index was out of
> > bounds.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +Close (
> > > +  IN EFI_PEI_SERVICES        **PeiServices,
> > > +  IN PEI_SMM_ACCESS_PPI      *This,
> > > +  IN UINTN                   DescriptorIndex
> > > +  )
> > > +{
> > > +  SMM_ACCESS_PRIVATE_DATA *SmmAccess;
> > > +  BOOLEAN                 OpenState;
> > > +  UINT8                   Index;
> > > +
> > > +  SmmAccess = SMM_ACCESS_PRIVATE_DATA_FROM_THIS (This);  if
> > > + (DescriptorIndex >= SmmAccess->NumberRegions) {
> > > +    DEBUG ((DEBUG_WARN, "SMRAM region out of range\n"));
> > > +
> > > +    return EFI_INVALID_PARAMETER;
> > > +  } else if (SmmAccess->SmramDesc[DescriptorIndex].RegionState &
> > EFI_SMRAM_LOCKED) {
> > > +    //
> > > +    // Cannot close a "locked" region
> > > +    //
> > > +    DEBUG ((DEBUG_WARN, "Cannot close a locked SMRAM region\n"));
> > > +
> > > +    return EFI_DEVICE_ERROR;
> > > +  }
> > > +
> > > +  if (SmmAccess->SmramDesc[DescriptorIndex].RegionState &
> > EFI_SMRAM_CLOSED) {
> > > +    return EFI_DEVICE_ERROR;
> > > +  }
> > > +
> > > +  SmmAccess->SmramDesc[DescriptorIndex].RegionState &= (UINT64)
> > > + ~EFI_SMRAM_OPEN;  SmmAccess-
> > >SmramDesc[DescriptorIndex].RegionState |=
> > > + (UINT64) (EFI_SMRAM_CLOSED | EFI_ALLOCATED);
> > > +
> > > +  //
> > > +  // Find out if any regions are still open  //  OpenState = FALSE;
> > > + for (Index = 0; Index < SmmAccess->NumberRegions; Index++) {
> > > +    if ((SmmAccess->SmramDesc[Index].RegionState & EFI_SMRAM_OPEN)
> > == EFI_SMRAM_OPEN) {
> > > +      OpenState = TRUE;
> > > +    }
> > > +  }
> > > +
> > > +  SmmAccess->SmmAccess.OpenState = OpenState;
> > > +  return EFI_SUCCESS;
> > > +}
> > > +
> > > +/**
> > > +  This routine accepts a request to "lock" SMRAM.  The
> > > +  region could be legacy AB or TSEG near top of physical memory.
> > > +  The use of "lock" means that the memory can no longer be opened
> > > +  to PEIM.
> > > +
> > > +  @param[in] PeiServices      - General purpose services available to every
> > PEIM.
> > > +  @param[in] This             -  Pointer to the SMM Access Interface.
> > > +  @param[in] DescriptorIndex  -  Region of SMRAM to Lock.
> > > +
> > > +  @retval EFI_SUCCESS            -  The region was successfully locked.
> > > +  @retval EFI_DEVICE_ERROR       -  The region could not be locked because
> > at least
> > > +                                    one range is still open.
> > > +  @retval EFI_INVALID_PARAMETER  -  The descriptor index was out of
> > bounds.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +Lock (
> > > +  IN EFI_PEI_SERVICES          **PeiServices,
> > > +  IN PEI_SMM_ACCESS_PPI        *This,
> > > +  IN UINTN                     DescriptorIndex
> > > +  )
> > > +{
> > > +  SMM_ACCESS_PRIVATE_DATA *SmmAccess;
> > > +
> > > +  SmmAccess = SMM_ACCESS_PRIVATE_DATA_FROM_THIS (This);  if
> > > + (DescriptorIndex >= SmmAccess->NumberRegions) {
> > > +    DEBUG ((DEBUG_WARN, "SMRAM region out of range\n"));
> > > +
> > > +    return EFI_INVALID_PARAMETER;
> > > +  } else if (SmmAccess->SmmAccess.OpenState) {
> > > +    DEBUG ((DEBUG_WARN, "Cannot lock SMRAM when SMRAM regions
> > are still
> > > + open\n"));
> > > +
> > > +    return EFI_DEVICE_ERROR;
> > > +  }
> > > +
> > > +  SmmAccess->SmramDesc[DescriptorIndex].RegionState |= (UINT64)
> > > + EFI_SMRAM_LOCKED;  SmmAccess->SmmAccess.LockState = TRUE;
> > > +
> > > +  return EFI_SUCCESS;
> > > +}
> > > +
> > > +/**
> > > +  This routine services a user request to discover the SMRAM
> > > +  capabilities of this platform.  This will report the possible
> > > +  ranges that are possible for SMRAM access, based upon the
> > > +  memory controller capabilities.
> > > +
> > > +  @param[in] PeiServices   - General purpose services available to every
> > PEIM.
> > > +  @param[in] This          -  Pointer to the SMRAM Access Interface.
> > > +  @param[in] SmramMapSize  -  Pointer to the variable containing size of
> > the
> > > +                              buffer to contain the description information.
> > > +  @param[in] SmramMap      -  Buffer containing the data describing the
> > Smram
> > > +                              region descriptors.
> > > +
> > > +  @retval EFI_BUFFER_TOO_SMALL  -  The user did not provide a sufficient
> > buffer.
> > > +  @retval EFI_SUCCESS           -  The user provided a sufficiently-sized buffer.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +GetCapabilities (
> > > +  IN EFI_PEI_SERVICES                **PeiServices,
> > > +  IN PEI_SMM_ACCESS_PPI              *This,
> > > +  IN OUT UINTN                       *SmramMapSize,
> > > +  IN OUT EFI_SMRAM_DESCRIPTOR        *SmramMap
> > > +  )
> > > +{
> > > +  EFI_STATUS              Status;
> > > +  SMM_ACCESS_PRIVATE_DATA *SmmAccess;
> > > +  UINTN                   NecessaryBufferSize;
> > > +
> > > +  SmmAccess           = SMM_ACCESS_PRIVATE_DATA_FROM_THIS (This);
> > > +  NecessaryBufferSize = SmmAccess->NumberRegions * sizeof
> > > + (EFI_SMRAM_DESCRIPTOR);  if (*SmramMapSize < NecessaryBufferSize)
> > {
> > > +    DEBUG ((DEBUG_WARN, "SMRAM Map Buffer too small\n"));
> > > +
> > > +    Status = EFI_BUFFER_TOO_SMALL;
> > > +  } else {
> > > +    CopyMem (SmramMap, SmmAccess->SmramDesc,
> > NecessaryBufferSize);
> > > +    Status = EFI_SUCCESS;
> > > +  }
> > > +
> > > +  *SmramMapSize = NecessaryBufferSize;
> > > +  return Status;
> > > +}
> > > +
> > > +/**
> > > +  This function is to install an SMM Access PPI
> > > +  - <b>Introduction</b> \n
> > > +    A module to install a PPI for controlling SMM mode memory access
> > basically for S3 resume usage.
> > > +
> > > +  - @pre
> > > +    - _PEI_MASTER_BOOT_MODE_PEIM_PPI: A PPI published by
> > foundation to get bootmode executed earlier.
> > > +    - _PEI_PERMANENT_MEMORY_INSTALLED_PPI: a PPI that will be
> > installed after memory controller initialization completed
> > > to indicate that physical memory is usable after this point.
> > > +
> > > +  - @result
> > > +    Publish _PEI_SMM_ACCESS_PPI.
> > > +
> > > +    @retval EFI_SUCCESS           - Ppi successfully started and installed.
> > > +    @retval EFI_NOT_FOUND         - Ppi can't be found.
> > > +    @retval EFI_OUT_OF_RESOURCES  - Ppi does not have enough
> > resources to initialize the driver.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +PeiInstallSmmAccessPpi (
> > > +  VOID
> > > +  )
> > > +{
> > > +  EFI_STATUS                      Status;
> > > +  UINTN                           Index;
> > > +  EFI_PEI_PPI_DESCRIPTOR          *PpiList;
> > > +  EFI_SMRAM_HOB_DESCRIPTOR_BLOCK  *DescriptorBlock;
> > > +  SMM_ACCESS_PRIVATE_DATA         *SmmAccessPrivate;
> > > +  VOID                            *HobList;
> > > +  EFI_BOOT_MODE                   BootMode;
> > > +
> > > +  Status = PeiServicesGetBootMode (&BootMode);  if (EFI_ERROR (Status))
> > > + {
> > > +    //
> > > +    // If not in S3 boot path. do nothing
> > > +    //
> > > +    return EFI_SUCCESS;
> > > +  }
> > > +
> > > +  if (BootMode != BOOT_ON_S3_RESUME) {
> > > +    return EFI_SUCCESS;
> > > +  }
> > > +  //
> > > +  // Initialize private data
> > > +  //
> > > +  SmmAccessPrivate  = AllocateZeroPool (sizeof (*SmmAccessPrivate));
> > > + ASSERT (SmmAccessPrivate != NULL);  if (SmmAccessPrivate == NULL) {
> > > +    return EFI_OUT_OF_RESOURCES;
> > > +  }
> > > +  PpiList           = AllocateZeroPool (sizeof (*PpiList));
> > > +  ASSERT (PpiList != NULL);
> > > +  if (PpiList == NULL) {
> > > +    return EFI_OUT_OF_RESOURCES;
> > > +  }
> > > +
> > > +  SmmAccessPrivate->Signature =
> > SMM_ACCESS_PRIVATE_DATA_SIGNATURE;
> > > +  SmmAccessPrivate->Handle    = NULL;
> > > +
> > > +  //
> > > +  // Get Hob list
> > > +  //
> > > +  HobList = GetFirstGuidHob (&gEfiSmmSmramMemoryGuid);  if (HobList
> > ==
> > > + NULL) {
> > > +    DEBUG ((DEBUG_WARN, "SmramMemoryReserve HOB not found\n"));
> > > +    return EFI_NOT_FOUND;
> > > +  }
> > > +
> > > +  DescriptorBlock = (EFI_SMRAM_HOB_DESCRIPTOR_BLOCK *) ((UINT8 *)
> > > + HobList + sizeof (EFI_HOB_GUID_TYPE));
> > > +
> > > +  //
> > > +  // Alloc space for SmmAccessPrivate->SmramDesc  //
> > > + SmmAccessPrivate->SmramDesc = AllocateZeroPool
> > > + ((DescriptorBlock->NumberOfSmmReservedRegions) * sizeof
> > (EFI_SMRAM_DESCRIPTOR));  if (SmmAccessPrivate->SmramDesc
> > > == NULL) {
> > > +    DEBUG ((DEBUG_WARN, "Alloc SmmAccessPrivate->SmramDesc
> > fail.\n"));
> > > +    return EFI_OUT_OF_RESOURCES;
> > > +  }
> > > +
> > > +  DEBUG ((DEBUG_INFO, "Alloc SmmAccessPrivate->SmramDesc
> > success.\n"));
> > > +
> > > +  //
> > > +  // use the hob to publish SMRAM capabilities  //  for (Index = 0;
> > > + Index < DescriptorBlock->NumberOfSmmReservedRegions; Index++) {
> > > +    SmmAccessPrivate->SmramDesc[Index].PhysicalStart  =
> > DescriptorBlock->Descriptor[Index].PhysicalStart;
> > > +    SmmAccessPrivate->SmramDesc[Index].CpuStart       = DescriptorBlock-
> > >Descriptor[Index].CpuStart;
> > > +    SmmAccessPrivate->SmramDesc[Index].PhysicalSize   =
> > DescriptorBlock->Descriptor[Index].PhysicalSize;
> > > +    SmmAccessPrivate->SmramDesc[Index].RegionState    =
> > DescriptorBlock->Descriptor[Index].RegionState;
> > > +  }
> > > +
> > > +  SmmAccessPrivate->NumberRegions             = Index;
> > > +  SmmAccessPrivate->SmmAccess.Open            = Open;
> > > +  SmmAccessPrivate->SmmAccess.Close           = Close;
> > > +  SmmAccessPrivate->SmmAccess.Lock            = Lock;
> > > +  SmmAccessPrivate->SmmAccess.GetCapabilities = GetCapabilities;
> > > +  SmmAccessPrivate->SmmAccess.LockState       = FALSE;
> > > +  SmmAccessPrivate->SmmAccess.OpenState       = FALSE;
> > > +
> > > +  //
> > > +  // Install PPI
> > > +  //
> > > +  PpiList->Flags  = (EFI_PEI_PPI_DESCRIPTOR_PPI |
> > EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST);
> > > +  PpiList->Guid   = &gPeiSmmAccessPpiGuid;
> > > +  PpiList->Ppi    = &SmmAccessPrivate->SmmAccess;
> > > +
> > > +  Status          = PeiServicesInstallPpi (PpiList);
> > > +  ASSERT_EFI_ERROR (Status);
> > > +
> > > +  return EFI_SUCCESS;
> > > +}
> > > diff --git
> > a/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/Library/PeiSmmAccessLi
> > b/PeiSmmAccessLib.inf
> > >
> > b/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/Library/PeiSmmAccessLi
> > b/PeiSmmAccessLib.inf
> > > new file mode 100644
> > > index 0000000000..0c6f5f65d8
> > > --- /dev/null
> > > +++
> > b/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/Library/PeiSmmAcce
> > > +++ ssLib/PeiSmmAccessLib.inf
> > > @@ -0,0 +1,42 @@
> > > +## @file
> > > +# Library description file for the SmmAccess module # # Copyright (c)
> > > +2019, Intel Corporation. All rights reserved.<BR> #
> > > +SPDX-License-Identifier: BSD-2-Clause-Patent # ##
> > > +
> > > +
> > > +[Defines]
> > > +INF_VERSION = 0x00010017
> > > +BASE_NAME = PeiSmmAccessLib
> > > +FILE_GUID = 54020881-B594-442A-8377-A57AFF98C7CF
> > > +VERSION_STRING = 1.0
> > > +MODULE_TYPE = PEIM
> > > +LIBRARY_CLASS = SmmAccessLib
> > > +
> > > +
> > > +[LibraryClasses]
> > > +BaseLib
> > > +BaseMemoryLib
> > > +HobLib
> > > +PciSegmentLib
> > > +PeiServicesLib
> > > +
> > > +
> > > +[Packages]
> > > +MdePkg/MdePkg.dec
> > > +MdeModulePkg/MdeModulePkg.dec
> > > +IntelSiliconPkg/IntelSiliconPkg.dec
> > > +
> > > +
> > > +[Sources]
> > > +PeiSmmAccessLib.c
> > > +
> > > +
> > > +[Ppis]
> > > +gPeiSmmAccessPpiGuid ## PRODUCES
> > > +
> > > +
> > > +[Guids]
> > > +gEfiSmmSmramMemoryGuid
> > > diff --git
> > a/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/SmmAccessDxe/SmmAc
> > cess.inf
> > >
> > b/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/SmmAccessDxe/SmmAc
> > cess.inf
> > > new file mode 100644
> > > index 0000000000..b1c988844f
> > > --- /dev/null
> > > +++
> > b/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/SmmAccessDxe/SmmAc
> > > +++ cess.inf
> > > @@ -0,0 +1,47 @@
> > > +## @file
> > > +# Component description file for the SmmAccess module # # Copyright (c)
> > > +2019, Intel Corporation. All rights reserved.<BR> #
> > > +SPDX-License-Identifier: BSD-2-Clause-Patent # ##
> > > +
> > > +
> > > +[Defines]
> > > +INF_VERSION = 0x00010017
> > > +BASE_NAME = SmmAccess
> > > +FILE_GUID = 1323C7F8-DAD5-4126-A54B-7A05FBF41515
> > > +VERSION_STRING = 1.0
> > > +MODULE_TYPE = DXE_DRIVER
> > > +ENTRY_POINT = SmmAccessDriverEntryPoint
> > > +
> > > +
> > > +[LibraryClasses]
> > > +UefiDriverEntryPoint
> > > +BaseLib
> > > +BaseMemoryLib
> > > +DebugLib
> > > +HobLib
> > > +
> > > +
> > > +[Packages]
> > > +MdePkg/MdePkg.dec
> > > +MdeModulePkg/MdeModulePkg.dec
> > > +IntelSiliconPkg/IntelSiliconPkg.dec
> > > +
> > > +
> > > +[Sources]
> > > +SmmAccessDriver.h
> > > +SmmAccessDriver.c
> > > +
> > > +
> > > +[Protocols]
> > > +gEfiSmmAccess2ProtocolGuid       ## PRODUCES
> > > +
> > > +
> > > +[Guids]
> > > +gEfiSmmSmramMemoryGuid
> > > +
> > > +
> > > +[Depex]
> > > +TRUE
> > > diff --git
> > a/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/SmmAccessDxe/SmmAc
> > cessDriver.c
> > >
> > b/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/SmmAccessDxe/SmmAc
> > cessDriver.c
> > > new file mode 100644
> > > index 0000000000..3d3c4ab206
> > > --- /dev/null
> > > +++
> > b/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/SmmAccessDxe/SmmAc
> > > +++ cessDriver.c
> > > @@ -0,0 +1,267 @@
> > > +/** @file
> > > +  This is the driver that publishes the SMM Access Protocol
> > > +  instance for System Agent.
> > > +
> > > +  Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
> > > +  SPDX-License-Identifier: BSD-2-Clause-Patent
> > > +
> > > +**/
> > > +#include "SmmAccessDriver.h"
> > > +
> > > +static SMM_ACCESS_PRIVATE_DATA  mSmmAccess;
> > > +
> > > +/**
> > > +  This is the standard EFI driver point that
> > > +  installs an SMM Access Protocol
> > > +
> > > +  @param[in] ImageHandle     - Handle for the image of this driver
> > > +  @param[in] SystemTable     - Pointer to the EFI System Table
> > > +
> > > +  @retval EFI_SUCCESS           - Protocol was installed successfully
> > > +  @exception EFI_UNSUPPORTED    - Protocol was not installed
> > > +  @retval EFI_NOT_FOUND         - Protocol can't be found.
> > > +  @retval EFI_OUT_OF_RESOURCES  - Protocol does not have enough
> > resources to initialize the driver.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +SmmAccessDriverEntryPoint (
> > > +  IN EFI_HANDLE         ImageHandle,
> > > +  IN EFI_SYSTEM_TABLE   *SystemTable
> > > +  )
> > > +{
> > > +  EFI_STATUS                      Status;
> > > +  UINTN                           Index;
> > > +  EFI_SMRAM_HOB_DESCRIPTOR_BLOCK  *DescriptorBlock;
> > > +  EFI_PEI_HOB_POINTERS            *Hob;
> > > +
> > > +  //
> > > +  // Initialize Global variables
> > > +  //
> > > +  ZeroMem (&mSmmAccess, sizeof (mSmmAccess));
> > > +
> > > +  mSmmAccess.Signature        =
> > SMM_ACCESS_PRIVATE_DATA_SIGNATURE;
> > > +  mSmmAccess.Handle           = NULL;
> > > +
> > > +  //
> > > +  // Get Hob list
> > > +  //
> > > +  Hob = GetFirstGuidHob (&gEfiSmmSmramMemoryGuid);  if (Hob ==
> > NULL) {
> > > +    DEBUG ((DEBUG_WARN, "SmramMemoryReserve HOB not found\n"));
> > > +    return EFI_NOT_FOUND;
> > > +  }
> > > +
> > > +  DescriptorBlock = (VOID *) ((UINT8 *) Hob + sizeof
> > > + (EFI_HOB_GUID_TYPE));
> > > +
> > > +  //
> > > +  // Alloc space for mSmmAccess.SmramDesc  //
> > mSmmAccess.SmramDesc =
> > > + AllocateZeroPool ((DescriptorBlock->NumberOfSmmReservedRegions) *
> > > + sizeof (EFI_SMRAM_DESCRIPTOR));  if (mSmmAccess.SmramDesc ==
> > NULL) {
> > > +    DEBUG ((DEBUG_WARN, "Alloc mSmmAccess.SmramDesc fail.\n"));
> > > +    return EFI_OUT_OF_RESOURCES;
> > > +  }
> > > +
> > > +  DEBUG ((DEBUG_INFO, "Alloc mSmmAccess.SmramDesc success.\n"));
> > > +
> > > +  //
> > > +  // Use the HOB to publish SMRAM capabilities  //  for (Index = 0;
> > > + Index < DescriptorBlock->NumberOfSmmReservedRegions; Index++) {
> > > +    mSmmAccess.SmramDesc[Index].PhysicalStart = DescriptorBlock-
> > >Descriptor[Index].PhysicalStart;
> > > +    mSmmAccess.SmramDesc[Index].CpuStart      = DescriptorBlock-
> > >Descriptor[Index].CpuStart;
> > > +    mSmmAccess.SmramDesc[Index].PhysicalSize  = DescriptorBlock-
> > >Descriptor[Index].PhysicalSize;
> > > +    mSmmAccess.SmramDesc[Index].RegionState   = DescriptorBlock-
> > >Descriptor[Index].RegionState;
> > > +  }
> > > +
> > > +  mSmmAccess.NumberRegions              = Index;
> > > +  mSmmAccess.SmmAccess.Open             = Open;
> > > +  mSmmAccess.SmmAccess.Close            = Close;
> > > +  mSmmAccess.SmmAccess.Lock             = Lock;
> > > +  mSmmAccess.SmmAccess.GetCapabilities  = GetCapabilities;
> > > +  mSmmAccess.SmmAccess.LockState        = FALSE;
> > > +  mSmmAccess.SmmAccess.OpenState        = FALSE;
> > > +
> > > +  //
> > > +  // Install our protocol interfaces on the device's handle  //  Status
> > > + = gBS->InstallMultipleProtocolInterfaces (
> > > +                  &mSmmAccess.Handle,
> > > +                  &gEfiSmmAccess2ProtocolGuid,
> > > +                  &mSmmAccess.SmmAccess,
> > > +                  NULL
> > > +                  );
> > > +  if (EFI_ERROR (Status)) {
> > > +    DEBUG ((DEBUG_WARN, "InstallMultipleProtocolInterfaces returned
> > %r\n", Status));
> > > +    return EFI_UNSUPPORTED;
> > > +  }
> > > +
> > > +  return EFI_SUCCESS;
> > > +}
> > > +
> > > +/**
> > > +  This routine accepts a request to "open" a region of SMRAM.  The
> > > +  region could be legacy ABSEG, HSEG, or TSEG near top of physical
> > memory.
> > > +  The use of "open" means that the memory is visible from all
> > > +boot-service
> > > +  and SMM agents.
> > > +
> > > +  @param[in] This               - Pointer to the SMM Access Interface.
> > > +
> > > +  @retval EFI_SUCCESS           - The region was successfully opened.
> > > +  @retval EFI_DEVICE_ERROR      - The region could not be opened because
> > locked by
> > > +                          chipset.
> > > +  @retval EFI_INVALID_PARAMETER - The descriptor index was out of
> > bounds.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +Open (
> > > +  IN EFI_SMM_ACCESS2_PROTOCOL *This
> > > +  )
> > > +{
> > > +  SMM_ACCESS_PRIVATE_DATA *SmmAccess;
> > > +  UINTN                   DescriptorIndex;
> > > +
> > > +  SmmAccess = SMM_ACCESS_PRIVATE_DATA_FROM_THIS (This);  for
> > > + (DescriptorIndex = 0; DescriptorIndex < SmmAccess->NumberRegions;
> > DescriptorIndex++) {
> > > +    if (SmmAccess->SmramDesc[DescriptorIndex].RegionState &
> > EFI_SMRAM_LOCKED) {
> > > +      DEBUG ((DEBUG_WARN, "Cannot open a locked SMRAM region\n"));
> > > +      return EFI_DEVICE_ERROR;
> > > +    }
> > > +  }
> > > +
> > > +  for (DescriptorIndex = 0; DescriptorIndex < SmmAccess-
> > >NumberRegions; DescriptorIndex++) {
> > > +    SmmAccess->SmramDesc[DescriptorIndex].RegionState &= (UINT64)
> > ~(EFI_SMRAM_CLOSED | EFI_ALLOCATED);
> > > +    SmmAccess->SmramDesc[DescriptorIndex].RegionState |= (UINT64)
> > > +EFI_SMRAM_OPEN;
> > > +  }
> > > +  SmmAccess->SmmAccess.OpenState = TRUE;
> > > +  return EFI_SUCCESS;
> > > +}
> > > +
> > > +/**
> > > +  This routine accepts a request to "close" a region of SMRAM.  The
> > > +  region could be legacy AB or TSEG near top of physical memory.
> > > +  The use of "close" means that the memory is only visible from SMM
> > > +agents,
> > > +  not from BS or RT code.
> > > +
> > > +  @param[in] This               - Pointer to the SMM Access Interface.
> > > +
> > > +  @retval EFI_SUCCESS           - The region was successfully closed.
> > > +  @retval EFI_DEVICE_ERROR      - The region could not be closed because
> > locked by chipset.
> > > +  @retval EFI_INVALID_PARAMETER - The descriptor index was out of
> > bounds.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +Close (
> > > +  IN EFI_SMM_ACCESS2_PROTOCOL  *This
> > > +  )
> > > +{
> > > +  SMM_ACCESS_PRIVATE_DATA *SmmAccess;
> > > +  BOOLEAN                 OpenState;
> > > +  UINT8                   Index;
> > > +  UINTN                   DescriptorIndex;
> > > +
> > > +  SmmAccess = SMM_ACCESS_PRIVATE_DATA_FROM_THIS (This);
> > > +
> > > +  for (DescriptorIndex = 0; DescriptorIndex < SmmAccess-
> > >NumberRegions; DescriptorIndex++) {
> > > +    if (SmmAccess->SmramDesc[DescriptorIndex].RegionState &
> > EFI_SMRAM_LOCKED) {
> > > +      DEBUG ((DEBUG_WARN, "Cannot close a locked SMRAM region\n"));
> > > +      continue;
> > > +    }
> > > +
> > > +    SmmAccess->SmramDesc[DescriptorIndex].RegionState &= (UINT64)
> > ~EFI_SMRAM_OPEN;
> > > +    SmmAccess->SmramDesc[DescriptorIndex].RegionState |= (UINT64)
> > > + (EFI_SMRAM_CLOSED | EFI_ALLOCATED);  }
> > > +
> > > +  //
> > > +  // Find out if any regions are still open  //  OpenState = FALSE;
> > > + for (Index = 0; Index < mSmmAccess.NumberRegions; Index++) {
> > > +    if ((SmmAccess->SmramDesc[Index].RegionState & EFI_SMRAM_OPEN)
> > == EFI_SMRAM_OPEN) {
> > > +      OpenState = TRUE;
> > > +    }
> > > +  }
> > > +
> > > +  SmmAccess->SmmAccess.OpenState = OpenState;
> > > +  return EFI_SUCCESS;
> > > +}
> > > +
> > > +/**
> > > +  This routine accepts a request to "lock" SMRAM.  The
> > > +  region could be legacy AB or TSEG near top of physical memory.
> > > +  The use of "lock" means that the memory can no longer be opened
> > > +  to BS state..
> > > +
> > > +  @param[in] This               - Pointer to the SMM Access Interface.
> > > +
> > > +  @retval EFI_SUCCESS           - The region was successfully locked.
> > > +  @retval EFI_DEVICE_ERROR      - The region could not be locked because
> > at least
> > > +                                  one range is still open.
> > > +  @retval EFI_INVALID_PARAMETER - The descriptor index was out of
> > bounds.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +Lock (
> > > +  IN EFI_SMM_ACCESS2_PROTOCOL *This
> > > +  )
> > > +{
> > > +  SMM_ACCESS_PRIVATE_DATA *SmmAccess;
> > > +  UINTN                   DescriptorIndex;
> > > +
> > > +  SmmAccess = SMM_ACCESS_PRIVATE_DATA_FROM_THIS (This);
> > > +
> > > +  if (SmmAccess->SmmAccess.OpenState) {
> > > +    DEBUG ((DEBUG_WARN, "Cannot lock SMRAM when SMRAM regions
> > are still open\n"));
> > > +    return EFI_DEVICE_ERROR;
> > > +  }
> > > +  for (DescriptorIndex = 0; DescriptorIndex < SmmAccess-
> > >NumberRegions; DescriptorIndex++) {
> > > +    SmmAccess->SmramDesc[DescriptorIndex].RegionState |=
> > > + EFI_SMRAM_LOCKED;  }  SmmAccess->SmmAccess.LockState = TRUE;
> > > +
> > > +  return EFI_SUCCESS;
> > > +}
> > > +
> > > +/**
> > > +  This routine services a user request to discover the SMRAM
> > > +  capabilities of this platform.  This will report the possible
> > > +  ranges that are possible for SMRAM access, based upon the
> > > +  memory controller capabilities.
> > > +
> > > +  @param[in] This                  - Pointer to the SMRAM Access Interface.
> > > +  @param[in] SmramMapSize          - Pointer to the variable containing size
> > of the
> > > +                                     buffer to contain the description information.
> > > +  @param[in] SmramMap              - Buffer containing the data describing the
> > Smram
> > > +                                     region descriptors.
> > > +
> > > +  @retval EFI_BUFFER_TOO_SMALL  - The user did not provide a sufficient
> > buffer.
> > > +  @retval EFI_SUCCESS           - The user provided a sufficiently-sized buffer.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +GetCapabilities (
> > > +  IN CONST EFI_SMM_ACCESS2_PROTOCOL  *This,
> > > +  IN OUT UINTN                       *SmramMapSize,
> > > +  IN OUT EFI_SMRAM_DESCRIPTOR        *SmramMap
> > > +  )
> > > +{
> > > +  EFI_STATUS              Status;
> > > +  SMM_ACCESS_PRIVATE_DATA *SmmAccess;
> > > +  UINTN                   NecessaryBufferSize;
> > > +
> > > +  SmmAccess           = SMM_ACCESS_PRIVATE_DATA_FROM_THIS (This);
> > > +
> > > +  NecessaryBufferSize = SmmAccess->NumberRegions * sizeof
> > > + (EFI_SMRAM_DESCRIPTOR);
> > > +
> > > +  if (*SmramMapSize < NecessaryBufferSize) {
> > > +    DEBUG ((DEBUG_WARN, "SMRAM Map Buffer too small\n"));
> > > +    Status = EFI_BUFFER_TOO_SMALL;
> > > +  } else {
> > > +    CopyMem (SmramMap, SmmAccess->SmramDesc,
> > NecessaryBufferSize);
> > > +    Status = EFI_SUCCESS;
> > > +  }
> > > +
> > > +  *SmramMapSize = NecessaryBufferSize;
> > > +
> > > +  return Status;
> > > +}
> > > diff --git
> > a/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/SmmAccessDxe/SmmAc
> > cessDriver.h
> > >
> > b/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/SmmAccessDxe/SmmAc
> > cessDriver.h
> > > new file mode 100644
> > > index 0000000000..c0ff3a250b
> > > --- /dev/null
> > > +++
> > b/Silicon/Intel/IntelSiliconPkg/Feature/SmmAccess/SmmAccessDxe/SmmAc
> > > +++ cessDriver.h
> > > @@ -0,0 +1,160 @@
> > > +/** @file
> > > +  Header file for SMM Access Driver.
> > > +
> > > +  Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
> > > +  SPDX-License-Identifier: BSD-2-Clause-Patent
> > > +
> > > +**/
> > > +#ifndef _SMM_ACCESS_DRIVER_H_
> > > +#define _SMM_ACCESS_DRIVER_H_
> > > +
> > > +#include <Library/BaseMemoryLib.h>
> > > +#include <Library/DebugLib.h>
> > > +#include <Library/HobLib.h>
> > > +#include <Library/PciLib.h>
> > > +#include <Library/MemoryAllocationLib.h> #include
> > > +<Library/UefiBootServicesTableLib.h>
> > > +#include <Uefi/UefiBaseType.h>
> > > +
> > > +#include <Guid/SmramMemoryReserve.h>
> > > +#include <Protocol/SmmAccess2.h>
> > > +#include <IndustryStandard/Pci22.h>
> > > +
> > > +#define SMM_ACCESS_PRIVATE_DATA_SIGNATURE SIGNATURE_32 ('4',
> > '5', 's',
> > > +'a')
> > > +
> > > +///
> > > +/// Private data
> > > +///
> > > +typedef struct {
> > > +  UINTN                           Signature;
> > > +  EFI_HANDLE                      Handle;
> > > +  EFI_SMM_ACCESS2_PROTOCOL        SmmAccess;
> > > +
> > > +  ///
> > > +  /// Local Data for SMM Access interface goes here
> > > +  ///
> > > +  UINTN                           NumberRegions;
> > > +  EFI_SMRAM_DESCRIPTOR            *SmramDesc;
> > > +} SMM_ACCESS_PRIVATE_DATA;
> > > +
> > > +#define SMM_ACCESS_PRIVATE_DATA_FROM_THIS(a) \
> > > +  CR (a, \
> > > +      SMM_ACCESS_PRIVATE_DATA, \
> > > +      SmmAccess, \
> > > +      SMM_ACCESS_PRIVATE_DATA_SIGNATURE \
> > > +      )
> > > +
> > > +//
> > > +// Prototypes
> > > +// Driver model protocol interface
> > > +//
> > > +/**
> > > +  <b>SMM Access Driver Entry Point</b>
> > > +  This driver installs an SMM Access Protocol
> > > +  - <b>Introduction</b> \n
> > > +    This module publishes the SMM access protocol.  The protocol is used
> > by the SMM Base driver to access the SMRAM region
> > > when the processor is not in SMM.
> > > +    The SMM Base driver uses the services provided by the SMM access
> > protocol to open SMRAM during post and copy the SMM
> > > handler.
> > > +    SMM access protocol is also used to close the SMRAM region once the
> > copying is done.
> > > +    Finally, the SMM access protocol provides services to "Lock" the
> > SMRAM region.
> > > +    Please refer the SMM Protocols section in the attached SMM CIS
> > Specification version 0.9 for further details.
> > > +    This driver is required if SMM is supported. Proper configuration of
> > SMM registers is recommended even if SMM is not
> > > supported.
> > > +
> > > +  - @result
> > > +    Publishes the _EFI_SMM_ACCESS_PROTOCOL: Documented in the
> > System
> > > + Management Mode Core Interface Specification, available at the URL:
> > > + http://www.intel.com/technology/framework/spec.htm
> > > +
> > > +  - <b>Porting Recommendations</b> \n
> > > +    No modification of this module is recommended.  Any modification
> > should be done in compliance with the
> > > _EFI_SMM_ACCESS_PROTOCOL protocol definition.
> > > +
> > > +  @param[in] ImageHandle     - Handle for the image of this driver
> > > +  @param[in] SystemTable     - Pointer to the EFI System Table
> > > +
> > > +  @retval EFI_SUCCESS     - Protocol was installed successfully
> > > +  @exception EFI_UNSUPPORTED - Protocol was not installed **/
> > > +EFI_STATUS EFIAPI SmmAccessDriverEntryPoint (
> > > +  IN EFI_HANDLE         ImageHandle,
> > > +  IN EFI_SYSTEM_TABLE   *SystemTable
> > > +  );
> > > +
> > > +/**
> > > +  This routine accepts a request to "open" a region of SMRAM.  The
> > > +  region could be legacy ABSEG, HSEG, or TSEG near top of physical
> > memory.
> > > +  The use of "open" means that the memory is visible from all
> > > +boot-service
> > > +  and SMM agents.
> > > +
> > > +  @param[in] This                  - Pointer to the SMM Access Interface.
> > > +
> > > +  @retval EFI_SUCCESS           - The region was successfully opened.
> > > +  @retval EFI_DEVICE_ERROR      - The region could not be opened because
> > locked by
> > > +                          chipset.
> > > +  @retval EFI_INVALID_PARAMETER - The descriptor index was out of
> > bounds.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +Open (
> > > +  IN EFI_SMM_ACCESS2_PROTOCOL *This
> > > +  );
> > > +
> > > +/**
> > > +  This routine accepts a request to "close" a region of SMRAM.  The
> > > +  region could be legacy AB or TSEG near top of physical memory.
> > > +  The use of "close" means that the memory is only visible from SMM
> > > +agents,
> > > +  not from BS or RT code.
> > > +
> > > +  @param[in] This                  - Pointer to the SMM Access Interface.
> > > +
> > > +  @retval EFI_SUCCESS           - The region was successfully closed.
> > > +  @retval EFI_DEVICE_ERROR      - The region could not be closed because
> > locked by
> > > +                            chipset.
> > > +  @retval EFI_INVALID_PARAMETER - The descriptor index was out of
> > bounds.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +Close (
> > > +  IN EFI_SMM_ACCESS2_PROTOCOL  *This
> > > +  );
> > > +
> > > +/**
> > > +  This routine accepts a request to "lock" SMRAM.  The
> > > +  region could be legacy AB or TSEG near top of physical memory.
> > > +  The use of "lock" means that the memory can no longer be opened
> > > +  to BS state..
> > > +
> > > +  @param[in] This                  - Pointer to the SMM Access Interface.
> > > +
> > > +  @retval EFI_SUCCESS           - The region was successfully locked.
> > > +  @retval EFI_DEVICE_ERROR      - The region could not be locked because
> > at least
> > > +                          one range is still open.
> > > +  @retval EFI_INVALID_PARAMETER - The descriptor index was out of
> > bounds.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +Lock (
> > > +  IN EFI_SMM_ACCESS2_PROTOCOL *This
> > > +  );
> > > +
> > > +/**
> > > +  This routine services a user request to discover the SMRAM
> > > +  capabilities of this platform.  This will report the possible
> > > +  ranges that are possible for SMRAM access, based upon the
> > > +  memory controller capabilities.
> > > +
> > > +  @param[in] This                  - Pointer to the SMRAM Access Interface.
> > > +  @param[in] SmramMapSize          - Pointer to the variable containing size
> > of the
> > > +                            buffer to contain the description information.
> > > +  @param[in] SmramMap              - Buffer containing the data describing the
> > Smram
> > > +                            region descriptors.
> > > +
> > > +  @retval EFI_BUFFER_TOO_SMALL  - The user did not provide a sufficient
> > buffer.
> > > +  @retval EFI_SUCCESS           - The user provided a sufficiently-sized buffer.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +GetCapabilities (
> > > +  IN CONST EFI_SMM_ACCESS2_PROTOCOL  *This,
> > > +  IN OUT UINTN                   *SmramMapSize,
> > > +  IN OUT EFI_SMRAM_DESCRIPTOR    *SmramMap
> > > +  );
> > > +#endif
> > > diff --git a/Silicon/Intel/IntelSiliconPkg/Include/Library/SmmAccessLib.h
> > > b/Silicon/Intel/IntelSiliconPkg/Include/Library/SmmAccessLib.h
> > > new file mode 100644
> > > index 0000000000..b7cb88f6ca
> > > --- /dev/null
> > > +++ b/Silicon/Intel/IntelSiliconPkg/Include/Library/SmmAccessLib.h
> > > @@ -0,0 +1,32 @@
> > > +/** @file
> > > +  Header file for SMM Access Driver.
> > > +
> > > +  Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
> > > +  SPDX-License-Identifier: BSD-2-Clause-Patent
> > > +
> > > +**/
> > > +#ifndef _SMM_ACCESS_H_
> > > +#define _SMM_ACCESS_H_
> > > +
> > > +/**
> > > +  This function is to install an SMM Access PPI
> > > +  - <b>Introduction</b> \n
> > > +    A module to install a PPI for controlling SMM mode memory access
> > basically for S3 resume usage.
> > > +
> > > +  - @pre
> > > +    - _PEI_MASTER_BOOT_MODE_PEIM_PPI: A PPI published by
> > foundation to get bootmode executed earlier.
> > > +    - _PEI_PERMANENT_MEMORY_INSTALLED_PPI: a PPI that will be
> > installed after memory controller initialization completed
> > > to indicate that physical memory is usable after this point.
> > > +
> > > +  - @result
> > > +    Publish _PEI_SMM_ACCESS_PPI.
> > > +
> > > +    @retval EFI_SUCCESS           - Ppi successfully started and installed.
> > > +    @retval EFI_NOT_FOUND         - Ppi can't be found.
> > > +    @retval EFI_OUT_OF_RESOURCES  - Ppi does not have enough
> > resources to initialize the driver.
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +PeiInstallSmmAccessPpi (
> > > +  VOID
> > > +  );
> > > +#endif
> > > --
> > > 2.16.2.windows.1