UefiCpuPkg: Implements MmSaveStateLib library instance

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4182

Implements MmSaveStateLib Library class for
AMD cpu family.

Cc: Paul Grimes <paul.grimes@amd.com>
Cc: Abner Chang <abner.chang@amd.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>

Signed-off-by: Abdul Lateef Attar <abdattar@amd.com>
Reviewed-by: Abner Chang <abner.chang@amd.com>

UefiCpuPkg/Library/MmSaveStateLib/MmSaveState.h

@@ -0,0 +1,94 @@
+/** @file
+  SMRAM Save State Map header file.
+
+  Copyright (c) 2010 - 2019, Intel Corporation. All rights reserved.<BR>
+  Copyright (C) 2023 Advanced Micro Devices, Inc. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef MM_SAVESTATE_H_
+#define MM_SAVESTATE_H_
+
+#include <Uefi/UefiBaseType.h>
+#include <Protocol/MmCpu.h>
+#include <Library/DebugLib.h>
+#include <Library/MmSaveStateLib.h>
+#include <Library/SmmServicesTableLib.h>
+#include <Library/BaseMemoryLib.h>
+
+// Macro used to simplify the lookup table entries of type CPU_MM_SAVE_STATE_REGISTER_RANGE
+#define MM_REGISTER_RANGE(Start, End)  { Start, End, End - Start + 1 }
+
+// Structure used to describe a range of registers
+typedef struct {
+  EFI_MM_SAVE_STATE_REGISTER    Start;
+  EFI_MM_SAVE_STATE_REGISTER    End;
+  UINTN                         Length;
+} CPU_MM_SAVE_STATE_REGISTER_RANGE;
+
+// Structure used to build a lookup table to retrieve the widths and offsets
+// associated with each supported EFI_MM_SAVE_STATE_REGISTER value
+
+typedef struct {
+  UINT8      Width32;
+  UINT8      Width64;
+  UINT16     Offset32;
+  UINT16     Offset64Lo;
+  UINT16     Offset64Hi;
+  BOOLEAN    Writeable;
+} CPU_MM_SAVE_STATE_LOOKUP_ENTRY;
+
+/**
+  Returns LMA value of the Processor.
+
+  @retval     UINT8     returns LMA bit value.
+**/
+UINT8
+MmSaveStateGetRegisterLma (
+  VOID
+  );
+
+/**
+  Read information from the CPU save state.
+
+  @param  Register  Specifies the CPU register to read form the save state.
+  @param  RegOffset Offset for the next register index.
+
+  @retval 0   Register is not valid
+  @retval >0  Index into mCpuWidthOffset[] associated with Register
+
+**/
+UINTN
+MmSaveStateGetRegisterIndex (
+  IN EFI_MM_SAVE_STATE_REGISTER  Register,
+  IN UINTN                       RegOffset
+  );
+
+/**
+  Read a CPU Save State register on the target processor.
+
+  This function abstracts the differences that whether the CPU Save State register is in the
+  IA32 CPU Save State Map or X64 CPU Save State Map.
+
+  This function supports reading a CPU Save State register in SMBase relocation handler.
+
+  @param[in]  CpuIndex       Specifies the zero-based index of the CPU save state.
+  @param[in]  RegisterIndex  Index into mCpuWidthOffset[] look up table.
+  @param[in]  Width          The number of bytes to read from the CPU save state.
+  @param[out] Buffer         Upon return, this holds the CPU register value read from the save state.
+
+  @retval EFI_SUCCESS           The register was read from Save State.
+  @retval EFI_NOT_FOUND         The register is not defined for the Save State of Processor.
+  @retval EFI_INVALID_PARAMTER  This or Buffer is NULL.
+
+**/
+EFI_STATUS
+MmSaveStateReadRegisterByIndex (
+  IN UINTN  CpuIndex,
+  IN UINTN  RegisterIndex,
+  IN UINTN  Width,
+  OUT VOID  *Buffer
+  );
+
+#endif