MdeModulePkg/Universal/Acpi/S3SaveStateDxe/AcpiS3ContextSave.c - device/linaro/bootloader/edk2 - Git at Google

 /** @file
   This is the implementation to save ACPI S3 Context.

 Copyright (c) 2006 - 2016, 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/HobLib.h>
 #include <Library/LockBoxLib.h>
 #include <Library/PcdLib.h>
 #include <Library/DebugLib.h>
 #include <Guid/AcpiS3Context.h>
 #include <Guid/Acpi.h>
 #include <IndustryStandard/Acpi.h>
 #include <Protocol/LockBox.h>

 //
 // 8 extra pages for PF handler.
 //
 #define EXTRA_PAGE_TABLE_PAGES   8

 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);
 }

 /**
   The function will check if long mode waking vector is supported.

   @param[in] Facs   Pointer to FACS table.

   @retval TRUE   Long mode waking vector is supported.
   @retval FALSE  Long mode waking vector is not supported.

 **/
 BOOLEAN
 IsLongModeWakingVectorSupport (
   IN EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *Facs
   )
 {
   if ((Facs == NULL) ||
       (Facs->Signature != EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE) ) {
     //
     // Something wrong with FACS.
     //
     return FALSE;
   }
   if ((Facs->Version == EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_VERSION) &&
       ((Facs->Flags & EFI_ACPI_4_0_64BIT_WAKE_SUPPORTED_F) != 0)) {
     //
     // BIOS supports 64bit waking vector.
     //
     if (FeaturePcdGet (PcdDxeIplSwitchToLongMode)) {
       return TRUE;
     }
   }
   return FALSE;
 }

 /**
   Allocates page table buffer.

   @param[in] LongModeWakingVectorSupport    Support long mode waking vector or not.

   If BootScriptExector driver will run in 64-bit mode, this function will establish the 1:1
   virtual to physical mapping page table when long mode waking vector is supported, otherwise
   create 4G page table when long mode waking vector is not supported and let PF handler to
   handle > 4G request.
   If BootScriptExector driver will not run in 64-bit mode, this function will do nothing.

   @return Page table base address.

 **/
 EFI_PHYSICAL_ADDRESS
 S3AllocatePageTablesBuffer (
   IN BOOLEAN    LongModeWakingVectorSupport
   )
 {
   if (FeaturePcdGet (PcdDxeIplSwitchToLongMode)) {
     UINTN                                         ExtraPageTablePages;
     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;
     }

     ExtraPageTablePages = 0;
     if (!LongModeWakingVectorSupport) {
       //
       // Create 4G page table when BIOS does not support long mode waking vector,
       // and let PF handler to handle > 4G request.
       //
       PhysicalAddressBits = 32;
       ExtraPageTablePages = EXTRA_PAGE_TABLE_PAGES;
     }

     //
     // 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);
     }

     TotalPageTableSize += ExtraPageTablePages;
     DEBUG ((EFI_D_ERROR, "AcpiS3ContextSave TotalPageTableSize - 0x%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;
   }
 }

 /**
   Callback function executed when the EndOfDxe event group is signaled.

   @param[in] Event      Event whose notification function is being invoked.
   @param[in] Context    The pointer to the notification function's context, which
                         is implementation-dependent.
 **/
 VOID
 EFIAPI
 AcpiS3ContextSaveOnEndOfDxe (
   IN EFI_EVENT  Event,
   IN VOID       *Context
   )
 {
   EFI_STATUS                                    Status;
   EFI_PHYSICAL_ADDRESS                          AcpiS3ContextBuffer;
   ACPI_S3_CONTEXT                               *AcpiS3Context;
   IA32_DESCRIPTOR                               *Idtr;
   IA32_IDT_GATE_DESCRIPTOR                      *IdtGate;
   EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE  *Facs;
   VOID                                          *Interface;

   DEBUG ((EFI_D_INFO, "AcpiS3ContextSave!\n"));

   Status = gBS->LocateProtocol (&gEfiLockBoxProtocolGuid, NULL, &Interface);
   if (EFI_ERROR (Status)) {
     DEBUG ((EFI_D_INFO | EFI_D_WARN, "ACPI S3 context can't be saved without LockBox!\n"));
     goto Done;
   }

   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
   //
   Facs = (EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *) FindAcpiFacsTable ();
   AcpiS3Context->AcpiFacsTable = (EFI_PHYSICAL_ADDRESS) (UINTN) Facs;
   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 = S3AllocatePageTablesBuffer (IsLongModeWakingVectorSupport (Facs));

   //
   // 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));
   DEBUG((EFI_D_INFO, "AcpiS3Context: BootScriptStackBase is 0x%8x\n", AcpiS3Context->BootScriptStackBase));
   DEBUG((EFI_D_INFO, "AcpiS3Context: BootScriptStackSize is 0x%8x\n", AcpiS3Context->BootScriptStackSize));

   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);

 Done:
   //
   // Close the event, deregistering the callback and freeing resources.
   //
   Status = gBS->CloseEvent (Event);
   ASSERT_EFI_ERROR (Status);
 }
	/** @file
	This is the implementation to save ACPI S3 Context.

	Copyright (c) 2006 - 2016, 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/HobLib.h>
	#include <Library/LockBoxLib.h>
	#include <Library/PcdLib.h>
	#include <Library/DebugLib.h>
	#include <Guid/AcpiS3Context.h>
	#include <Guid/Acpi.h>
	#include <IndustryStandard/Acpi.h>
	#include <Protocol/LockBox.h>

	//
	// 8 extra pages for PF handler.
	//
	#define EXTRA_PAGE_TABLE_PAGES 8

	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);
	}

	/**
	The function will check if long mode waking vector is supported.

	@param[in] Facs Pointer to FACS table.

	@retval TRUE Long mode waking vector is supported.
	@retval FALSE Long mode waking vector is not supported.

	**/
	BOOLEAN
	IsLongModeWakingVectorSupport (
	IN EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *Facs
	)
	{
	if ((Facs == NULL) \|\|
	(Facs->Signature != EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE) ) {
	//
	// Something wrong with FACS.
	//
	return FALSE;
	}
	if ((Facs->Version == EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_VERSION) &&
	((Facs->Flags & EFI_ACPI_4_0_64BIT_WAKE_SUPPORTED_F) != 0)) {
	//
	// BIOS supports 64bit waking vector.
	//
	if (FeaturePcdGet (PcdDxeIplSwitchToLongMode)) {
	return TRUE;
	}
	}
	return FALSE;
	}

	/**
	Allocates page table buffer.

	@param[in] LongModeWakingVectorSupport Support long mode waking vector or not.

	If BootScriptExector driver will run in 64-bit mode, this function will establish the 1:1
	virtual to physical mapping page table when long mode waking vector is supported, otherwise
	create 4G page table when long mode waking vector is not supported and let PF handler to
	handle > 4G request.
	If BootScriptExector driver will not run in 64-bit mode, this function will do nothing.

	@return Page table base address.

	**/
	EFI_PHYSICAL_ADDRESS
	S3AllocatePageTablesBuffer (
	IN BOOLEAN LongModeWakingVectorSupport
	)
	{
	if (FeaturePcdGet (PcdDxeIplSwitchToLongMode)) {
	UINTN ExtraPageTablePages;
	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;
	}

	ExtraPageTablePages = 0;
	if (!LongModeWakingVectorSupport) {
	//
	// Create 4G page table when BIOS does not support long mode waking vector,
	// and let PF handler to handle > 4G request.
	//
	PhysicalAddressBits = 32;
	ExtraPageTablePages = EXTRA_PAGE_TABLE_PAGES;
	}

	//
	// 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);
	}

	TotalPageTableSize += ExtraPageTablePages;
	DEBUG ((EFI_D_ERROR, "AcpiS3ContextSave TotalPageTableSize - 0x%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;
	}
	}

	/**
	Callback function executed when the EndOfDxe event group is signaled.

	@param[in] Event Event whose notification function is being invoked.
	@param[in] Context The pointer to the notification function's context, which
	is implementation-dependent.
	**/
	VOID
	EFIAPI
	AcpiS3ContextSaveOnEndOfDxe (
	IN EFI_EVENT Event,
	IN VOID *Context
	)
	{
	EFI_STATUS Status;
	EFI_PHYSICAL_ADDRESS AcpiS3ContextBuffer;
	ACPI_S3_CONTEXT *AcpiS3Context;
	IA32_DESCRIPTOR *Idtr;
	IA32_IDT_GATE_DESCRIPTOR *IdtGate;
	EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *Facs;
	VOID *Interface;

	DEBUG ((EFI_D_INFO, "AcpiS3ContextSave!\n"));

	Status = gBS->LocateProtocol (&gEfiLockBoxProtocolGuid, NULL, &Interface);
	if (EFI_ERROR (Status)) {
	DEBUG ((EFI_D_INFO \| EFI_D_WARN, "ACPI S3 context can't be saved without LockBox!\n"));
	goto Done;
	}

	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
	//
	Facs = (EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *) FindAcpiFacsTable ();
	AcpiS3Context->AcpiFacsTable = (EFI_PHYSICAL_ADDRESS) (UINTN) Facs;
	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 = S3AllocatePageTablesBuffer (IsLongModeWakingVectorSupport (Facs));

	//
	// 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));
	DEBUG((EFI_D_INFO, "AcpiS3Context: BootScriptStackBase is 0x%8x\n", AcpiS3Context->BootScriptStackBase));
	DEBUG((EFI_D_INFO, "AcpiS3Context: BootScriptStackSize is 0x%8x\n", AcpiS3Context->BootScriptStackSize));

	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);

	Done:
	//
	// Close the event, deregistering the callback and freeing resources.
	//
	Status = gBS->CloseEvent (Event);
	ASSERT_EFI_ERROR (Status);
	}