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

Copyright (c) 2006 - 2015, 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 <Guid/AcpiVariableCompatibility.h>
#include <Guid/AcpiS3Context.h>
#include <Guid/Acpi.h>
#include <Protocol/AcpiS3Save.h>
#include <IndustryStandard/Acpi.h>

#include "AcpiS3Save.h"

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

/**
  Hook point for AcpiVariableThunkPlatform for InstallAcpiS3Save.
**/
VOID
InstallAcpiS3SaveThunk (
  VOID
  );

/**
  Hook point for AcpiVariableThunkPlatform for S3Ready.

  @param AcpiS3Context   ACPI s3 context
**/
VOID
S3ReadyThunkPlatform (
  IN ACPI_S3_CONTEXT      *AcpiS3Context
  );

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);
}

/**
  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->XFirmwareWakingVector != 0) {
    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, "AcpiS3Save 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;  
  }
}

/**
  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;
}

/**
  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;
  EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE  *Facs;

  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
  //
  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);

  if (FeaturePcdGet(PcdFrameworkCompatibilitySupport)) {
    S3ReadyThunkPlatform (AcpiS3Context);
  }

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

  if (FeaturePcdGet(PcdFrameworkCompatibilitySupport)) {
    InstallAcpiS3SaveThunk ();
  }

  Status = gBS->InstallProtocolInterface (
                  &ImageHandle,
                  &gEfiAcpiS3SaveProtocolGuid,
                  EFI_NATIVE_INTERFACE,
                  &mS3Save
                  );
  ASSERT_EFI_ERROR (Status);
  return Status;
}