OvmfPkg/AcpiS3SaveDxe/AcpiS3Save.c - third_party/edk2 - Git at Google

 /** @file
   This is an implementation of the ACPI S3 Save protocol.  This is defined in
   S3 boot path specification 0.9.

 Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>

 This program and the accompanying materials
 are licensed and made available under the terms and conditions
 of the BSD License which accompanies this distribution.  The
 full text of the license may be found at
 http://opensource.org/licenses/bsd-license.php

 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

 **/

 #include <PiDxe.h>
 #include <Library/BaseLib.h>
 #include <Library/BaseMemoryLib.h>
 #include <Library/UefiBootServicesTableLib.h>
 #include <Library/UefiRuntimeServicesTableLib.h>
 #include <Library/HobLib.h>
 #include <Library/LockBoxLib.h>
 #include <Library/PcdLib.h>
 #include <Library/DebugLib.h>
 #include <Library/QemuFwCfgLib.h>
 #include <Guid/AcpiVariableCompatibility.h>
 #include <Guid/AcpiS3Context.h>
 #include <Guid/Acpi.h>
 #include <Protocol/AcpiS3Save.h>
 #include <Protocol/S3SaveState.h>
 #include <Protocol/DxeSmmReadyToLock.h>
 #include <Protocol/LockBox.h>
 #include <IndustryStandard/Acpi.h>

 #include "AcpiS3Save.h"

 UINTN     mLegacyRegionSize;

 EFI_ACPI_S3_SAVE_PROTOCOL mS3Save = {
   LegacyGetS3MemorySize,
   S3Ready,
 };

 EFI_GUID              mAcpiS3IdtrProfileGuid = {
   0xdea652b0, 0xd587, 0x4c54, { 0xb5, 0xb4, 0xc6, 0x82, 0xe7, 0xa0, 0xaa, 0x3d }
 };

 /**
   Allocate memory below 4G memory address.

   This function allocates memory below 4G memory address.

   @param  MemoryType   Memory type of memory to allocate.
   @param  Size         Size of memory to allocate.

   @return Allocated address for output.

 **/
 VOID*
 AllocateMemoryBelow4G (
   IN EFI_MEMORY_TYPE    MemoryType,
   IN UINTN              Size
   )
 {
   UINTN                 Pages;
   EFI_PHYSICAL_ADDRESS  Address;
   EFI_STATUS            Status;
   VOID*                 Buffer;

   Pages = EFI_SIZE_TO_PAGES (Size);
   Address = 0xffffffff;

   Status  = gBS->AllocatePages (
                    AllocateMaxAddress,
                    MemoryType,
                    Pages,
                    &Address
                    );
   ASSERT_EFI_ERROR (Status);

   Buffer = (VOID *) (UINTN) Address;
   ZeroMem (Buffer, Size);

   return Buffer;
 }

 /**

   This function scan ACPI table in RSDT.

   @param Rsdt      ACPI RSDT
   @param Signature ACPI table signature

   @return ACPI table

 **/
 VOID *
 ScanTableInRSDT (
   IN EFI_ACPI_DESCRIPTION_HEADER    *Rsdt,
   IN UINT32                         Signature
   )
 {
   UINTN                              Index;
   UINT32                             EntryCount;
   UINT32                             *EntryPtr;
   EFI_ACPI_DESCRIPTION_HEADER        *Table;

   if (Rsdt == NULL) {
     return NULL;
   }

   EntryCount = (Rsdt->Length - sizeof (EFI_ACPI_DESCRIPTION_HEADER)) / sizeof(UINT32);

   EntryPtr = (UINT32 *)(Rsdt + 1);
   for (Index = 0; Index < EntryCount; Index ++, EntryPtr ++) {
     Table = (EFI_ACPI_DESCRIPTION_HEADER *)((UINTN)(*EntryPtr));
     if (Table->Signature == Signature) {
       return Table;
     }
   }

   return NULL;
 }

 /**

   This function scan ACPI table in XSDT.

   @param Xsdt      ACPI XSDT
   @param Signature ACPI table signature

   @return ACPI table

 **/
 VOID *
 ScanTableInXSDT (
   IN EFI_ACPI_DESCRIPTION_HEADER    *Xsdt,
   IN UINT32                         Signature
   )
 {
   UINTN                          Index;
   UINT32                         EntryCount;
   UINT64                         EntryPtr;
   UINTN                          BasePtr;
   EFI_ACPI_DESCRIPTION_HEADER    *Table;

   if (Xsdt == NULL) {
     return NULL;
   }

   EntryCount = (Xsdt->Length - sizeof (EFI_ACPI_DESCRIPTION_HEADER)) / sizeof(UINT64);

   BasePtr = (UINTN)(Xsdt + 1);
   for (Index = 0; Index < EntryCount; Index ++) {
     CopyMem (&EntryPtr, (VOID *)(BasePtr + Index * sizeof(UINT64)), sizeof(UINT64));
     Table = (EFI_ACPI_DESCRIPTION_HEADER *)((UINTN)(EntryPtr));
     if (Table->Signature == Signature) {
       return Table;
     }
   }

   return NULL;
 }

 /**
   To find Facs in FADT.

   @param Fadt   FADT table pointer

   @return  Facs table pointer.
 **/
 EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE  *
 FindAcpiFacsFromFadt (
   IN EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE     *Fadt
   )
 {
   EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE  *Facs;
   UINT64                                        Data64;

   if (Fadt == NULL) {
     return NULL;
   }

   if (Fadt->Header.Revision < EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_REVISION) {
     Facs = (EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *)(UINTN)Fadt->FirmwareCtrl;
   } else {
     if (Fadt->FirmwareCtrl != 0) {
       Facs = (EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *)(UINTN)Fadt->FirmwareCtrl;
     } else {
       CopyMem (&Data64, &Fadt->XFirmwareCtrl, sizeof(UINT64));
       Facs = (EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *)(UINTN)Data64;
     }
   }
   return Facs;
 }

 /**
   To find Facs in Acpi tables.

   To find Firmware ACPI control strutcure in Acpi Tables since the S3 waking vector is stored
   in the table.

   @param AcpiTableGuid   The guid used to find ACPI table in UEFI ConfigurationTable.

   @return  Facs table pointer.
 **/
 EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE  *
 FindAcpiFacsTableByAcpiGuid (
   IN EFI_GUID  *AcpiTableGuid
   )
 {
   EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER  *Rsdp;
   EFI_ACPI_DESCRIPTION_HEADER                   *Rsdt;
   EFI_ACPI_DESCRIPTION_HEADER                   *Xsdt;
   EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE     *Fadt;
   EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE  *Facs;
   UINTN                                         Index;

   Rsdp  = NULL;
   //
   // found ACPI table RSD_PTR from system table
   //
   for (Index = 0; Index < gST->NumberOfTableEntries; Index++) {
     if (CompareGuid (&(gST->ConfigurationTable[Index].VendorGuid), AcpiTableGuid)) {
       //
       // A match was found.
       //
       Rsdp = gST->ConfigurationTable[Index].VendorTable;
       break;
     }
   }

   if (Rsdp == NULL) {
     return NULL;
   }

   //
   // Search XSDT
   //
   if (Rsdp->Revision >= EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER_REVISION) {
     Xsdt = (EFI_ACPI_DESCRIPTION_HEADER *)(UINTN) Rsdp->XsdtAddress;
     Fadt = ScanTableInXSDT (Xsdt, EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE);
     if (Fadt != NULL) {
       Facs = FindAcpiFacsFromFadt (Fadt);
       if (Facs != NULL) {
         return Facs;
       }
     }
   }

   //
   // Search RSDT
   //
   Rsdt = (EFI_ACPI_DESCRIPTION_HEADER *)(UINTN) Rsdp->RsdtAddress;
   Fadt = ScanTableInRSDT (Rsdt, EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE);
   if (Fadt != NULL) {
     Facs = FindAcpiFacsFromFadt (Fadt);
     if (Facs != NULL) {
       return Facs;
     }
   }

   return NULL;
 }

 /**
   To find Facs in Acpi tables.

   To find Firmware ACPI control strutcure in Acpi Tables since the S3 waking vector is stored
   in the table.

   @return  Facs table pointer.
 **/
 EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE  *
 FindAcpiFacsTable (
   VOID
   )
 {
   EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *Facs;

   Facs = FindAcpiFacsTableByAcpiGuid (&gEfiAcpi20TableGuid);
   if (Facs != NULL) {
     return Facs;
   }

   return FindAcpiFacsTableByAcpiGuid (&gEfiAcpi10TableGuid);
 }

 /**
   Allocates and fills in the Page Directory and Page Table Entries to
   establish a 1:1 Virtual to Physical mapping.
   If BootScriptExector driver will run in 64-bit mode, this function will establish the 1:1
   virtual to physical mapping page table.
   If BootScriptExector driver will not run in 64-bit mode, this function will do nothing.

   @return  the 1:1 Virtual to Physical identity mapping page table base address.

 **/
 EFI_PHYSICAL_ADDRESS
 S3CreateIdentityMappingPageTables (
   VOID
   )
 {
   if (FeaturePcdGet (PcdDxeIplSwitchToLongMode)) {
     UINT32                                        RegEax;
     UINT32                                        RegEdx;
     UINT8                                         PhysicalAddressBits;
     UINT32                                        NumberOfPml4EntriesNeeded;
     UINT32                                        NumberOfPdpEntriesNeeded;
     EFI_PHYSICAL_ADDRESS                          S3NvsPageTableAddress;
     UINTN                                         TotalPageTableSize;
     VOID                                          *Hob;
     BOOLEAN                                       Page1GSupport;

     Page1GSupport = FALSE;
     if (PcdGetBool(PcdUse1GPageTable)) {
       AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL);
       if (RegEax >= 0x80000001) {
         AsmCpuid (0x80000001, NULL, NULL, NULL, &RegEdx);
         if ((RegEdx & BIT26) != 0) {
           Page1GSupport = TRUE;
         }
       }
     }

     //
     // 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;
     }

     //
     // Calculate the table entries needed.
     //
     if (PhysicalAddressBits <= 39 ) {
       NumberOfPml4EntriesNeeded = 1;
       NumberOfPdpEntriesNeeded = (UINT32)LShiftU64 (1, (PhysicalAddressBits - 30));
     } else {
       NumberOfPml4EntriesNeeded = (UINT32)LShiftU64 (1, (PhysicalAddressBits - 39));
       NumberOfPdpEntriesNeeded = 512;
     }

     //
     // We need calculate whole page size then allocate once, because S3 restore page table does not know each page in Nvs.
     //
     if (!Page1GSupport) {
       TotalPageTableSize = (UINTN)(1 + NumberOfPml4EntriesNeeded + NumberOfPml4EntriesNeeded * NumberOfPdpEntriesNeeded);
     } else {
       TotalPageTableSize = (UINTN)(1 + NumberOfPml4EntriesNeeded);
     }
     DEBUG ((EFI_D_ERROR, "TotalPageTableSize - %x pages\n", TotalPageTableSize));

     //
     // By architecture only one PageMapLevel4 exists - so lets allocate storage for it.
     //
     S3NvsPageTableAddress = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocateMemoryBelow4G (EfiReservedMemoryType, EFI_PAGES_TO_SIZE(TotalPageTableSize));
     ASSERT (S3NvsPageTableAddress != 0);
     return S3NvsPageTableAddress;
   } else {
     //
     // If DXE is running 32-bit mode, no need to establish page table.
     //
     return  (EFI_PHYSICAL_ADDRESS) 0;
   }
 }

 /**
   Gets the buffer of legacy memory below 1 MB
   This function is to get the buffer in legacy memory below 1MB that is required during S3 resume.

   @param This           A pointer to the EFI_ACPI_S3_SAVE_PROTOCOL instance.
   @param Size           The returned size of legacy memory below 1 MB.

   @retval EFI_SUCCESS           Size is successfully returned.
   @retval EFI_INVALID_PARAMETER The pointer Size is NULL.

 **/
 EFI_STATUS
 EFIAPI
 LegacyGetS3MemorySize (
   IN  EFI_ACPI_S3_SAVE_PROTOCOL   *This,
   OUT UINTN                       *Size
   )
 {
   if (Size == NULL) {
     return EFI_INVALID_PARAMETER;
   }

   *Size = mLegacyRegionSize;
   return EFI_SUCCESS;
 }

 /**
   Save the S3 boot script.

   Note that we trigger DxeSmmReadyToLock here -- otherwise the script wouldn't
   be saved actually. Triggering this protocol installation event in turn locks
   down SMM, so no further changes to LockBoxes or SMRAM are possible
   afterwards.
 **/
 STATIC
 VOID
 EFIAPI
 SaveS3BootScript (
   VOID
   )
 {
   EFI_STATUS                 Status;
   EFI_S3_SAVE_STATE_PROTOCOL *BootScript;
   EFI_HANDLE                 Handle;
   STATIC CONST UINT8         Info[] = { 0xDE, 0xAD, 0xBE, 0xEF };

   Status = gBS->LocateProtocol (&gEfiS3SaveStateProtocolGuid, NULL,
                   (VOID **) &BootScript);
   ASSERT_EFI_ERROR (Status);

   //
   // Despite the opcode documentation in the PI spec, the protocol
   // implementation embeds a deep copy of the info in the boot script, rather
   // than storing just a pointer to runtime or NVS storage.
   //
   Status = BootScript->Write(BootScript, EFI_BOOT_SCRIPT_INFORMATION_OPCODE,
                          (UINT32) sizeof Info,
                          (EFI_PHYSICAL_ADDRESS)(UINTN) &Info);
   ASSERT_EFI_ERROR (Status);

   Handle = NULL;
   Status = gBS->InstallProtocolInterface (&Handle,
                   &gEfiDxeSmmReadyToLockProtocolGuid, EFI_NATIVE_INTERFACE,
                   NULL);
   ASSERT_EFI_ERROR (Status);
 }


 /**
   Prepares all information that is needed in the S3 resume boot path.

   Allocate the resources or prepare informations and save in ACPI variable set for S3 resume boot path

   @param This                 A pointer to the EFI_ACPI_S3_SAVE_PROTOCOL instance.
   @param LegacyMemoryAddress  The base address of legacy memory.

   @retval EFI_NOT_FOUND         Some necessary information cannot be found.
   @retval EFI_SUCCESS           All information was saved successfully.
   @retval EFI_OUT_OF_RESOURCES  Resources were insufficient to save all the information.
   @retval EFI_INVALID_PARAMETER The memory range is not located below 1 MB.

 **/
 EFI_STATUS
 EFIAPI
 S3Ready (
   IN EFI_ACPI_S3_SAVE_PROTOCOL    *This,
   IN VOID                         *LegacyMemoryAddress
   )
 {
   EFI_STATUS                                    Status;
   EFI_PHYSICAL_ADDRESS                          AcpiS3ContextBuffer;
   ACPI_S3_CONTEXT                               *AcpiS3Context;
   STATIC BOOLEAN                                AlreadyEntered;
   IA32_DESCRIPTOR                               *Idtr;
   IA32_IDT_GATE_DESCRIPTOR                      *IdtGate;

   DEBUG ((EFI_D_INFO, "S3Ready!\n"));

   //
   // Platform may invoke AcpiS3Save->S3Save() before ExitPmAuth, because we need save S3 information there, while BDS ReadyToBoot may invoke it again.
   // So if 2nd S3Save() is triggered later, we need ignore it.
   //
   if (AlreadyEntered) {
     return EFI_SUCCESS;
   }
   AlreadyEntered = TRUE;

   AcpiS3Context = AllocateMemoryBelow4G (EfiReservedMemoryType, sizeof(*AcpiS3Context));
   ASSERT (AcpiS3Context != NULL);
   AcpiS3ContextBuffer = (EFI_PHYSICAL_ADDRESS)(UINTN)AcpiS3Context;

   //
   // Get ACPI Table because we will save its position to variable
   //
   AcpiS3Context->AcpiFacsTable = (EFI_PHYSICAL_ADDRESS)(UINTN)FindAcpiFacsTable ();
   ASSERT (AcpiS3Context->AcpiFacsTable != 0);

   IdtGate = AllocateMemoryBelow4G (EfiReservedMemoryType, sizeof(IA32_IDT_GATE_DESCRIPTOR) * 0x100 + sizeof(IA32_DESCRIPTOR));
   Idtr = (IA32_DESCRIPTOR *)(IdtGate + 0x100);
   Idtr->Base  = (UINTN)IdtGate;
   Idtr->Limit = (UINT16)(sizeof(IA32_IDT_GATE_DESCRIPTOR) * 0x100 - 1);
   AcpiS3Context->IdtrProfile = (EFI_PHYSICAL_ADDRESS)(UINTN)Idtr;

   Status = SaveLockBox (
              &mAcpiS3IdtrProfileGuid,
              (VOID *)(UINTN)Idtr,
              (UINTN)sizeof(IA32_DESCRIPTOR)
              );
   ASSERT_EFI_ERROR (Status);

   Status = SetLockBoxAttributes (&mAcpiS3IdtrProfileGuid, LOCK_BOX_ATTRIBUTE_RESTORE_IN_PLACE);
   ASSERT_EFI_ERROR (Status);

   //
   // Allocate page table
   //
   AcpiS3Context->S3NvsPageTableAddress = S3CreateIdentityMappingPageTables ();

   //
   // Allocate stack
   //
   AcpiS3Context->BootScriptStackSize = PcdGet32 (PcdS3BootScriptStackSize);
   AcpiS3Context->BootScriptStackBase = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocateMemoryBelow4G (EfiReservedMemoryType, PcdGet32 (PcdS3BootScriptStackSize));
   ASSERT (AcpiS3Context->BootScriptStackBase != 0);

   //
   // Allocate a code buffer < 4G for S3 debug to load external code, set invalid code instructions in it.
   //
   AcpiS3Context->S3DebugBufferAddress = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocateMemoryBelow4G (EfiReservedMemoryType, EFI_PAGE_SIZE);
   SetMem ((VOID *)(UINTN)AcpiS3Context->S3DebugBufferAddress, EFI_PAGE_SIZE, 0xff);

   DEBUG((EFI_D_INFO, "AcpiS3Context: AcpiFacsTable is 0x%8x\n", AcpiS3Context->AcpiFacsTable));
   DEBUG((EFI_D_INFO, "AcpiS3Context: IdtrProfile is 0x%8x\n", AcpiS3Context->IdtrProfile));
   DEBUG((EFI_D_INFO, "AcpiS3Context: S3NvsPageTableAddress is 0x%8x\n", AcpiS3Context->S3NvsPageTableAddress));
   DEBUG((EFI_D_INFO, "AcpiS3Context: S3DebugBufferAddress is 0x%8x\n", AcpiS3Context->S3DebugBufferAddress));

   Status = SaveLockBox (
              &gEfiAcpiVariableGuid,
              &AcpiS3ContextBuffer,
              sizeof(AcpiS3ContextBuffer)
              );
   ASSERT_EFI_ERROR (Status);

   Status = SaveLockBox (
              &gEfiAcpiS3ContextGuid,
              (VOID *)(UINTN)AcpiS3Context,
              (UINTN)sizeof(*AcpiS3Context)
              );
   ASSERT_EFI_ERROR (Status);

   Status = SetLockBoxAttributes (&gEfiAcpiS3ContextGuid, LOCK_BOX_ATTRIBUTE_RESTORE_IN_PLACE);
   ASSERT_EFI_ERROR (Status);

   //
   // Save the boot script too. Note that this requires/includes emitting the
   // DxeSmmReadyToLock event, which in turn locks down SMM.
   //
   SaveS3BootScript ();
   return EFI_SUCCESS;
 }

 /**
   The Driver Entry Point.

   The function is the driver Entry point which will produce AcpiS3SaveProtocol.

   @param ImageHandle   A handle for the image that is initializing this driver
   @param SystemTable   A pointer to the EFI system table

   @retval EFI_SUCCESS:              Driver initialized successfully
   @retval EFI_LOAD_ERROR:           Failed to Initialize or has been loaded
   @retval EFI_OUT_OF_RESOURCES      Could not allocate needed resources

 **/
 EFI_STATUS
 EFIAPI
 InstallAcpiS3Save (
   IN EFI_HANDLE           ImageHandle,
   IN EFI_SYSTEM_TABLE     *SystemTable
   )
 {
   EFI_STATUS        Status;

   if (!QemuFwCfgS3Enabled()) {
     return EFI_LOAD_ERROR;
   }

   if (!FeaturePcdGet(PcdPlatformCsmSupport)) {
     //
     // More memory for no CSM tip, because GDT need relocation
     //
     mLegacyRegionSize = 0x250;
   } else {
     mLegacyRegionSize = 0x100;
   }

   Status = gBS->InstallMultipleProtocolInterfaces (
                   &ImageHandle,
                   &gEfiAcpiS3SaveProtocolGuid, &mS3Save,
                   &gEfiLockBoxProtocolGuid, NULL,
                   NULL
                   );
   ASSERT_EFI_ERROR (Status);
   return Status;
 }
	/** @file
	This is an implementation of the ACPI S3 Save protocol. This is defined in
	S3 boot path specification 0.9.

	Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>

	This program and the accompanying materials
	are licensed and made available under the terms and conditions
	of the BSD License which accompanies this distribution. The
	full text of the license may be found at
	http://opensource.org/licenses/bsd-license.php

	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

	**/

	#include <PiDxe.h>
	#include <Library/BaseLib.h>
	#include <Library/BaseMemoryLib.h>
	#include <Library/UefiBootServicesTableLib.h>
	#include <Library/UefiRuntimeServicesTableLib.h>
	#include <Library/HobLib.h>
	#include <Library/LockBoxLib.h>
	#include <Library/PcdLib.h>
	#include <Library/DebugLib.h>
	#include <Library/QemuFwCfgLib.h>
	#include <Guid/AcpiVariableCompatibility.h>
	#include <Guid/AcpiS3Context.h>
	#include <Guid/Acpi.h>
	#include <Protocol/AcpiS3Save.h>
	#include <Protocol/S3SaveState.h>
	#include <Protocol/DxeSmmReadyToLock.h>
	#include <Protocol/LockBox.h>
	#include <IndustryStandard/Acpi.h>

	#include "AcpiS3Save.h"

	UINTN mLegacyRegionSize;

	EFI_ACPI_S3_SAVE_PROTOCOL mS3Save = {
	LegacyGetS3MemorySize,
	S3Ready,
	};

	EFI_GUID mAcpiS3IdtrProfileGuid = {
	0xdea652b0, 0xd587, 0x4c54, { 0xb5, 0xb4, 0xc6, 0x82, 0xe7, 0xa0, 0xaa, 0x3d }
	};

	/**
	Allocate memory below 4G memory address.

	This function allocates memory below 4G memory address.

	@param MemoryType Memory type of memory to allocate.
	@param Size Size of memory to allocate.

	@return Allocated address for output.

	**/
	VOID*
	AllocateMemoryBelow4G (
	IN EFI_MEMORY_TYPE MemoryType,
	IN UINTN Size
	)
	{
	UINTN Pages;
	EFI_PHYSICAL_ADDRESS Address;
	EFI_STATUS Status;
	VOID* Buffer;

	Pages = EFI_SIZE_TO_PAGES (Size);
	Address = 0xffffffff;

	Status = gBS->AllocatePages (
	AllocateMaxAddress,
	MemoryType,
	Pages,
	&Address
	);
	ASSERT_EFI_ERROR (Status);

	Buffer = (VOID *) (UINTN) Address;
	ZeroMem (Buffer, Size);

	return Buffer;
	}

	/**

	This function scan ACPI table in RSDT.

	@param Rsdt ACPI RSDT
	@param Signature ACPI table signature

	@return ACPI table

	**/
	VOID *
	ScanTableInRSDT (
	IN EFI_ACPI_DESCRIPTION_HEADER *Rsdt,
	IN UINT32 Signature
	)
	{
	UINTN Index;
	UINT32 EntryCount;
	UINT32 *EntryPtr;
	EFI_ACPI_DESCRIPTION_HEADER *Table;

	if (Rsdt == NULL) {
	return NULL;
	}

	EntryCount = (Rsdt->Length - sizeof (EFI_ACPI_DESCRIPTION_HEADER)) / sizeof(UINT32);

	EntryPtr = (UINT32 *)(Rsdt + 1);
	for (Index = 0; Index < EntryCount; Index ++, EntryPtr ++) {
	Table = (EFI_ACPI_DESCRIPTION_HEADER )((UINTN)(EntryPtr));
	if (Table->Signature == Signature) {
	return Table;
	}
	}

	return NULL;
	}

	/**

	This function scan ACPI table in XSDT.

	@param Xsdt ACPI XSDT
	@param Signature ACPI table signature

	@return ACPI table

	**/
	VOID *
	ScanTableInXSDT (
	IN EFI_ACPI_DESCRIPTION_HEADER *Xsdt,
	IN UINT32 Signature
	)
	{
	UINTN Index;
	UINT32 EntryCount;
	UINT64 EntryPtr;
	UINTN BasePtr;
	EFI_ACPI_DESCRIPTION_HEADER *Table;

	if (Xsdt == NULL) {
	return NULL;
	}

	EntryCount = (Xsdt->Length - sizeof (EFI_ACPI_DESCRIPTION_HEADER)) / sizeof(UINT64);

	BasePtr = (UINTN)(Xsdt + 1);
	for (Index = 0; Index < EntryCount; Index ++) {
	CopyMem (&EntryPtr, (VOID )(BasePtr + Index sizeof(UINT64)), sizeof(UINT64));
	Table = (EFI_ACPI_DESCRIPTION_HEADER *)((UINTN)(EntryPtr));
	if (Table->Signature == Signature) {
	return Table;
	}
	}

	return NULL;
	}

	/**
	To find Facs in FADT.

	@param Fadt FADT table pointer

	@return Facs table pointer.
	**/
	EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *
	FindAcpiFacsFromFadt (
	IN EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE *Fadt
	)
	{
	EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *Facs;
	UINT64 Data64;

	if (Fadt == NULL) {
	return NULL;
	}

	if (Fadt->Header.Revision < EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_REVISION) {
	Facs = (EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *)(UINTN)Fadt->FirmwareCtrl;
	} else {
	if (Fadt->FirmwareCtrl != 0) {
	Facs = (EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *)(UINTN)Fadt->FirmwareCtrl;
	} else {
	CopyMem (&Data64, &Fadt->XFirmwareCtrl, sizeof(UINT64));
	Facs = (EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *)(UINTN)Data64;
	}
	}
	return Facs;
	}

	/**
	To find Facs in Acpi tables.

	To find Firmware ACPI control strutcure in Acpi Tables since the S3 waking vector is stored
	in the table.

	@param AcpiTableGuid The guid used to find ACPI table in UEFI ConfigurationTable.

	@return Facs table pointer.
	**/
	EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *
	FindAcpiFacsTableByAcpiGuid (
	IN EFI_GUID *AcpiTableGuid
	)
	{
	EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER *Rsdp;
	EFI_ACPI_DESCRIPTION_HEADER *Rsdt;
	EFI_ACPI_DESCRIPTION_HEADER *Xsdt;
	EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE *Fadt;
	EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *Facs;
	UINTN Index;

	Rsdp = NULL;
	//
	// found ACPI table RSD_PTR from system table
	//
	for (Index = 0; Index < gST->NumberOfTableEntries; Index++) {
	if (CompareGuid (&(gST->ConfigurationTable[Index].VendorGuid), AcpiTableGuid)) {
	//
	// A match was found.
	//
	Rsdp = gST->ConfigurationTable[Index].VendorTable;
	break;
	}
	}

	if (Rsdp == NULL) {
	return NULL;
	}

	//
	// Search XSDT
	//
	if (Rsdp->Revision >= EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER_REVISION) {
	Xsdt = (EFI_ACPI_DESCRIPTION_HEADER *)(UINTN) Rsdp->XsdtAddress;
	Fadt = ScanTableInXSDT (Xsdt, EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE);
	if (Fadt != NULL) {
	Facs = FindAcpiFacsFromFadt (Fadt);
	if (Facs != NULL) {
	return Facs;
	}
	}
	}

	//
	// Search RSDT
	//
	Rsdt = (EFI_ACPI_DESCRIPTION_HEADER *)(UINTN) Rsdp->RsdtAddress;
	Fadt = ScanTableInRSDT (Rsdt, EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE);
	if (Fadt != NULL) {
	Facs = FindAcpiFacsFromFadt (Fadt);
	if (Facs != NULL) {
	return Facs;
	}
	}

	return NULL;
	}

	/**
	To find Facs in Acpi tables.

	To find Firmware ACPI control strutcure in Acpi Tables since the S3 waking vector is stored
	in the table.

	@return Facs table pointer.
	**/
	EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *
	FindAcpiFacsTable (
	VOID
	)
	{
	EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *Facs;

	Facs = FindAcpiFacsTableByAcpiGuid (&gEfiAcpi20TableGuid);
	if (Facs != NULL) {
	return Facs;
	}

	return FindAcpiFacsTableByAcpiGuid (&gEfiAcpi10TableGuid);
	}

	/**
	Allocates and fills in the Page Directory and Page Table Entries to
	establish a 1:1 Virtual to Physical mapping.
	If BootScriptExector driver will run in 64-bit mode, this function will establish the 1:1
	virtual to physical mapping page table.
	If BootScriptExector driver will not run in 64-bit mode, this function will do nothing.

	@return the 1:1 Virtual to Physical identity mapping page table base address.

	**/
	EFI_PHYSICAL_ADDRESS
	S3CreateIdentityMappingPageTables (
	VOID
	)
	{
	if (FeaturePcdGet (PcdDxeIplSwitchToLongMode)) {
	UINT32 RegEax;
	UINT32 RegEdx;
	UINT8 PhysicalAddressBits;
	UINT32 NumberOfPml4EntriesNeeded;
	UINT32 NumberOfPdpEntriesNeeded;
	EFI_PHYSICAL_ADDRESS S3NvsPageTableAddress;
	UINTN TotalPageTableSize;
	VOID *Hob;
	BOOLEAN Page1GSupport;

	Page1GSupport = FALSE;
	if (PcdGetBool(PcdUse1GPageTable)) {
	AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL);
	if (RegEax >= 0x80000001) {
	AsmCpuid (0x80000001, NULL, NULL, NULL, &RegEdx);
	if ((RegEdx & BIT26) != 0) {
	Page1GSupport = TRUE;
	}
	}
	}

	//
	// 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;
	}

	//
	// Calculate the table entries needed.
	//
	if (PhysicalAddressBits <= 39 ) {
	NumberOfPml4EntriesNeeded = 1;
	NumberOfPdpEntriesNeeded = (UINT32)LShiftU64 (1, (PhysicalAddressBits - 30));
	} else {
	NumberOfPml4EntriesNeeded = (UINT32)LShiftU64 (1, (PhysicalAddressBits - 39));
	NumberOfPdpEntriesNeeded = 512;
	}

	//
	// We need calculate whole page size then allocate once, because S3 restore page table does not know each page in Nvs.
	//
	if (!Page1GSupport) {
	TotalPageTableSize = (UINTN)(1 + NumberOfPml4EntriesNeeded + NumberOfPml4EntriesNeeded * NumberOfPdpEntriesNeeded);
	} else {
	TotalPageTableSize = (UINTN)(1 + NumberOfPml4EntriesNeeded);
	}
	DEBUG ((EFI_D_ERROR, "TotalPageTableSize - %x pages\n", TotalPageTableSize));

	//
	// By architecture only one PageMapLevel4 exists - so lets allocate storage for it.
	//
	S3NvsPageTableAddress = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocateMemoryBelow4G (EfiReservedMemoryType, EFI_PAGES_TO_SIZE(TotalPageTableSize));
	ASSERT (S3NvsPageTableAddress != 0);
	return S3NvsPageTableAddress;
	} else {
	//
	// If DXE is running 32-bit mode, no need to establish page table.
	//
	return (EFI_PHYSICAL_ADDRESS) 0;
	}
	}

	/**
	Gets the buffer of legacy memory below 1 MB
	This function is to get the buffer in legacy memory below 1MB that is required during S3 resume.

	@param This A pointer to the EFI_ACPI_S3_SAVE_PROTOCOL instance.
	@param Size The returned size of legacy memory below 1 MB.

	@retval EFI_SUCCESS Size is successfully returned.
	@retval EFI_INVALID_PARAMETER The pointer Size is NULL.

	**/
	EFI_STATUS
	EFIAPI
	LegacyGetS3MemorySize (
	IN EFI_ACPI_S3_SAVE_PROTOCOL *This,
	OUT UINTN *Size
	)
	{
	if (Size == NULL) {
	return EFI_INVALID_PARAMETER;
	}

	*Size = mLegacyRegionSize;
	return EFI_SUCCESS;
	}

	/**
	Save the S3 boot script.

	Note that we trigger DxeSmmReadyToLock here -- otherwise the script wouldn't
	be saved actually. Triggering this protocol installation event in turn locks
	down SMM, so no further changes to LockBoxes or SMRAM are possible
	afterwards.
	**/
	STATIC
	VOID
	EFIAPI
	SaveS3BootScript (
	VOID
	)
	{
	EFI_STATUS Status;
	EFI_S3_SAVE_STATE_PROTOCOL *BootScript;
	EFI_HANDLE Handle;
	STATIC CONST UINT8 Info[] = { 0xDE, 0xAD, 0xBE, 0xEF };

	Status = gBS->LocateProtocol (&gEfiS3SaveStateProtocolGuid, NULL,
	(VOID **) &BootScript);
	ASSERT_EFI_ERROR (Status);

	//
	// Despite the opcode documentation in the PI spec, the protocol
	// implementation embeds a deep copy of the info in the boot script, rather
	// than storing just a pointer to runtime or NVS storage.
	//
	Status = BootScript->Write(BootScript, EFI_BOOT_SCRIPT_INFORMATION_OPCODE,
	(UINT32) sizeof Info,
	(EFI_PHYSICAL_ADDRESS)(UINTN) &Info);
	ASSERT_EFI_ERROR (Status);

	Handle = NULL;
	Status = gBS->InstallProtocolInterface (&Handle,
	&gEfiDxeSmmReadyToLockProtocolGuid, EFI_NATIVE_INTERFACE,
	NULL);
	ASSERT_EFI_ERROR (Status);
	}


	/**
	Prepares all information that is needed in the S3 resume boot path.

	Allocate the resources or prepare informations and save in ACPI variable set for S3 resume boot path

	@param This A pointer to the EFI_ACPI_S3_SAVE_PROTOCOL instance.
	@param LegacyMemoryAddress The base address of legacy memory.

	@retval EFI_NOT_FOUND Some necessary information cannot be found.
	@retval EFI_SUCCESS All information was saved successfully.
	@retval EFI_OUT_OF_RESOURCES Resources were insufficient to save all the information.
	@retval EFI_INVALID_PARAMETER The memory range is not located below 1 MB.

	**/
	EFI_STATUS
	EFIAPI
	S3Ready (
	IN EFI_ACPI_S3_SAVE_PROTOCOL *This,
	IN VOID *LegacyMemoryAddress
	)
	{
	EFI_STATUS Status;
	EFI_PHYSICAL_ADDRESS AcpiS3ContextBuffer;
	ACPI_S3_CONTEXT *AcpiS3Context;
	STATIC BOOLEAN AlreadyEntered;
	IA32_DESCRIPTOR *Idtr;
	IA32_IDT_GATE_DESCRIPTOR *IdtGate;

	DEBUG ((EFI_D_INFO, "S3Ready!\n"));

	//
	// Platform may invoke AcpiS3Save->S3Save() before ExitPmAuth, because we need save S3 information there, while BDS ReadyToBoot may invoke it again.
	// So if 2nd S3Save() is triggered later, we need ignore it.
	//
	if (AlreadyEntered) {
	return EFI_SUCCESS;
	}
	AlreadyEntered = TRUE;

	AcpiS3Context = AllocateMemoryBelow4G (EfiReservedMemoryType, sizeof(*AcpiS3Context));
	ASSERT (AcpiS3Context != NULL);
	AcpiS3ContextBuffer = (EFI_PHYSICAL_ADDRESS)(UINTN)AcpiS3Context;

	//
	// Get ACPI Table because we will save its position to variable
	//
	AcpiS3Context->AcpiFacsTable = (EFI_PHYSICAL_ADDRESS)(UINTN)FindAcpiFacsTable ();
	ASSERT (AcpiS3Context->AcpiFacsTable != 0);

	IdtGate = AllocateMemoryBelow4G (EfiReservedMemoryType, sizeof(IA32_IDT_GATE_DESCRIPTOR) * 0x100 + sizeof(IA32_DESCRIPTOR));
	Idtr = (IA32_DESCRIPTOR *)(IdtGate + 0x100);
	Idtr->Base = (UINTN)IdtGate;
	Idtr->Limit = (UINT16)(sizeof(IA32_IDT_GATE_DESCRIPTOR) * 0x100 - 1);
	AcpiS3Context->IdtrProfile = (EFI_PHYSICAL_ADDRESS)(UINTN)Idtr;

	Status = SaveLockBox (
	&mAcpiS3IdtrProfileGuid,
	(VOID *)(UINTN)Idtr,
	(UINTN)sizeof(IA32_DESCRIPTOR)
	);
	ASSERT_EFI_ERROR (Status);

	Status = SetLockBoxAttributes (&mAcpiS3IdtrProfileGuid, LOCK_BOX_ATTRIBUTE_RESTORE_IN_PLACE);
	ASSERT_EFI_ERROR (Status);

	//
	// Allocate page table
	//
	AcpiS3Context->S3NvsPageTableAddress = S3CreateIdentityMappingPageTables ();

	//
	// Allocate stack
	//
	AcpiS3Context->BootScriptStackSize = PcdGet32 (PcdS3BootScriptStackSize);
	AcpiS3Context->BootScriptStackBase = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocateMemoryBelow4G (EfiReservedMemoryType, PcdGet32 (PcdS3BootScriptStackSize));
	ASSERT (AcpiS3Context->BootScriptStackBase != 0);

	//
	// Allocate a code buffer < 4G for S3 debug to load external code, set invalid code instructions in it.
	//
	AcpiS3Context->S3DebugBufferAddress = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocateMemoryBelow4G (EfiReservedMemoryType, EFI_PAGE_SIZE);
	SetMem ((VOID *)(UINTN)AcpiS3Context->S3DebugBufferAddress, EFI_PAGE_SIZE, 0xff);

	DEBUG((EFI_D_INFO, "AcpiS3Context: AcpiFacsTable is 0x%8x\n", AcpiS3Context->AcpiFacsTable));
	DEBUG((EFI_D_INFO, "AcpiS3Context: IdtrProfile is 0x%8x\n", AcpiS3Context->IdtrProfile));
	DEBUG((EFI_D_INFO, "AcpiS3Context: S3NvsPageTableAddress is 0x%8x\n", AcpiS3Context->S3NvsPageTableAddress));
	DEBUG((EFI_D_INFO, "AcpiS3Context: S3DebugBufferAddress is 0x%8x\n", AcpiS3Context->S3DebugBufferAddress));

	Status = SaveLockBox (
	&gEfiAcpiVariableGuid,
	&AcpiS3ContextBuffer,
	sizeof(AcpiS3ContextBuffer)
	);
	ASSERT_EFI_ERROR (Status);

	Status = SaveLockBox (
	&gEfiAcpiS3ContextGuid,
	(VOID *)(UINTN)AcpiS3Context,
	(UINTN)sizeof(*AcpiS3Context)
	);
	ASSERT_EFI_ERROR (Status);

	Status = SetLockBoxAttributes (&gEfiAcpiS3ContextGuid, LOCK_BOX_ATTRIBUTE_RESTORE_IN_PLACE);
	ASSERT_EFI_ERROR (Status);

	//
	// Save the boot script too. Note that this requires/includes emitting the
	// DxeSmmReadyToLock event, which in turn locks down SMM.
	//
	SaveS3BootScript ();
	return EFI_SUCCESS;
	}

	/**
	The Driver Entry Point.

	The function is the driver Entry point which will produce AcpiS3SaveProtocol.

	@param ImageHandle A handle for the image that is initializing this driver
	@param SystemTable A pointer to the EFI system table

	@retval EFI_SUCCESS: Driver initialized successfully
	@retval EFI_LOAD_ERROR: Failed to Initialize or has been loaded
	@retval EFI_OUT_OF_RESOURCES Could not allocate needed resources

	**/
	EFI_STATUS
	EFIAPI
	InstallAcpiS3Save (
	IN EFI_HANDLE ImageHandle,
	IN EFI_SYSTEM_TABLE *SystemTable
	)
	{
	EFI_STATUS Status;

	if (!QemuFwCfgS3Enabled()) {
	return EFI_LOAD_ERROR;
	}

	if (!FeaturePcdGet(PcdPlatformCsmSupport)) {
	//
	// More memory for no CSM tip, because GDT need relocation
	//
	mLegacyRegionSize = 0x250;
	} else {
	mLegacyRegionSize = 0x100;
	}

	Status = gBS->InstallMultipleProtocolInterfaces (
	&ImageHandle,
	&gEfiAcpiS3SaveProtocolGuid, &mS3Save,
	&gEfiLockBoxProtocolGuid, NULL,
	NULL
	);
	ASSERT_EFI_ERROR (Status);
	return Status;
	}