OvmfPkg/SmmAccess/SmramInternal.h

/** @file

  Functions and types shared by the SMM accessor PEI and DXE modules.

  Copyright (C) 2015, Red Hat, Inc.

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

**/

#include <Pi/PiMultiPhase.h>

//
// We'll have two SMRAM ranges.
//
// The first is a tiny one that hosts an SMM_S3_RESUME_STATE object, to be
// filled in by the CPU SMM driver during normal boot, for the PEI instance of
// the LockBox library (which will rely on the object during S3 resume).
//
// The other SMRAM range is the main one, for the SMM core and the SMM drivers.
//
typedef enum {
  DescIdxSmmS3ResumeState = 0,
  DescIdxMain             = 1,
  DescIdxCount            = 2
} DESCRIPTOR_INDEX;

//
// The value of PcdQ35TsegMbytes is saved into this variable at module startup.
//
extern UINT16 mQ35TsegMbytes;

/**
  Save PcdQ35TsegMbytes into mQ35TsegMbytes.
**/
VOID
InitQ35TsegMbytes (
  VOID
  );

/**
  Save PcdQ35SmramAtDefaultSmbase into mQ35SmramAtDefaultSmbase.
**/
VOID
InitQ35SmramAtDefaultSmbase (
  VOID
  );

/**
  Read the MCH_SMRAM and ESMRAMC registers, and update the LockState and
  OpenState fields in the PEI_SMM_ACCESS_PPI / EFI_SMM_ACCESS2_PROTOCOL object,
  from the D_LCK and T_EN bits.

  PEI_SMM_ACCESS_PPI and EFI_SMM_ACCESS2_PROTOCOL member functions can rely on
  the LockState and OpenState fields being up-to-date on entry, and they need
  to restore the same invariant on exit, if they touch the bits in question.

  @param[out] LockState  Reflects the D_LCK bit on output; TRUE iff SMRAM is
                         locked.
  @param[out] OpenState  Reflects the inverse of the T_EN bit on output; TRUE
                         iff SMRAM is open.
**/
VOID
GetStates (
  OUT BOOLEAN *LockState,
  OUT BOOLEAN *OpenState
  );

//
// The functions below follow the PEI_SMM_ACCESS_PPI and
// EFI_SMM_ACCESS2_PROTOCOL member declarations. The PeiServices and This
// pointers are removed (TSEG doesn't depend on them), and so is the
// DescriptorIndex parameter (TSEG doesn't support range-wise locking).
//
// The LockState and OpenState members that are common to both
// PEI_SMM_ACCESS_PPI and EFI_SMM_ACCESS2_PROTOCOL are taken and updated in
// isolation from the rest of the (non-shared) members.
//

EFI_STATUS
SmramAccessOpen (
  OUT BOOLEAN *LockState,
  OUT BOOLEAN *OpenState
  );

EFI_STATUS
SmramAccessClose (
  OUT BOOLEAN *LockState,
  OUT BOOLEAN *OpenState
  );

EFI_STATUS
SmramAccessLock (
  OUT    BOOLEAN *LockState,
  IN OUT BOOLEAN *OpenState
  );

EFI_STATUS
SmramAccessGetCapabilities (
  IN BOOLEAN                  LockState,
  IN BOOLEAN                  OpenState,
  IN OUT UINTN                *SmramMapSize,
  IN OUT EFI_SMRAM_DESCRIPTOR *SmramMap
  );