/** @file

Copyright (c) 2018, 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 that 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 "S3NvramSave.h"
#include <Protocol/Decompress.h>
#include <Library/CompressLib.h>
#include <Protocol/VariableLock.h>

/**

  This function will retrieve the S3 data from HOBs produced by MRC
  and will save it to NVRAM if the data is absent or different from
  the previously saved data.

  @param VOID

  @retval VOID

**/
VOID
SaveS3StructToNvram (
  VOID
  )
{
  EFI_STATUS                      Status;
  UINTN                           BufferSize;
  UINTN                           CurrentHobSize;
  UINTN                           S3ChunkSize;
  CHAR16                          EfiMemoryConfigVariable[] = L"MemoryConfig0";
  EFI_HOB_GUID_TYPE               *GuidHob      = NULL;
  VOID                            *HobData      = NULL;
  VOID                            *VariableData = NULL;
  
  UINTN                           CompressedDataSize;
  UINT32                          ScratchSize;
  VOID                            *CompressedData = NULL;
  VOID                            *Scratch = NULL;
  EFI_DECOMPRESS_PROTOCOL         *Decompress = NULL;
  VOID                            *CompressedVariableData = NULL;
  UINTN                           CompressedBufferSize;
  EDKII_VARIABLE_LOCK_PROTOCOL    *VariableLock = NULL;
  
  //
  // Get first S3 data HOB
  //
  GuidHob = GetFirstGuidHob (&gEfiMemoryConfigDataHobGuid);

  Status = gBS->LocateProtocol (&gEfiDecompressProtocolGuid, NULL, (VOID **) &Decompress);
  DEBUG((DEBUG_INFO, "[SaveMemoryConfigEntryPoint] Locate Decompress protocol - %r\n", Status));
  if(EFI_ERROR (Status)) {
    ASSERT_EFI_ERROR (Status);
    return;
  }
  
  Status = gBS->LocateProtocol(&gEdkiiVariableLockProtocolGuid, NULL, (VOID **)&VariableLock);
  DEBUG((DEBUG_INFO, "[SaveMemoryConfigEntryPoint] Locate Variable Lock protocol - %r\n", Status));
  ASSERT_EFI_ERROR(Status); 

  while (TRUE) {
    if (GuidHob == NULL) {
      break;
    }
    HobData = GET_GUID_HOB_DATA(GuidHob); 
    CurrentHobSize = GET_GUID_HOB_DATA_SIZE (GuidHob);

    DEBUG((EFI_D_INFO, "   Current Hob Size(bytes) is: %d\n", CurrentHobSize));
    //
    // Use the HOB data to save Memory Configuration Data
    //
    BufferSize = CurrentHobSize;
    Status = gBS->AllocatePool (
                    EfiBootServicesData,
                    BufferSize,
                    (VOID**)&VariableData
                    );

    ASSERT (VariableData != NULL); 
    S3ChunkSize = MAX_HOB_ENTRY_SIZE / 8;
    DEBUG((EFI_D_INFO, "   S3ChunkSize Hob Size(bytes): %d\n", S3ChunkSize));

    while (CurrentHobSize) {
      if (S3ChunkSize > CurrentHobSize) {
        S3ChunkSize = CurrentHobSize;
      }
      BufferSize = S3ChunkSize;
      CompressedDataSize = 0;
      ScratchSize = 0;
      Status = gRT->GetVariable (
                      EfiMemoryConfigVariable,
                      &gEfiMemoryConfigDataGuid,
                      NULL,
                      &CompressedDataSize,
                      NULL
                      );
                    
      if(Status == EFI_BUFFER_TOO_SMALL) {
        Status = gBS->AllocatePool (
                        EfiBootServicesData,
                        CompressedDataSize,
                        (VOID**)&CompressedData
                        );
        ASSERT (Status == EFI_SUCCESS); 
      }

      if(!EFI_ERROR (Status))
      {
        Status = gRT->GetVariable (
                        EfiMemoryConfigVariable,
                        &gEfiMemoryConfigDataGuid,
                        NULL,
                        &CompressedDataSize,
                        CompressedData
                        );

        if (!EFI_ERROR (Status)) {
         Status = Decompress->GetInfo (
                                Decompress,
                                CompressedData,
                                (UINT32)CompressedDataSize,
                                (UINT32*)&BufferSize,
                                &ScratchSize
                                );
        }

        if (!EFI_ERROR (Status)) {
          Status = gBS->AllocatePool (
                          EfiBootServicesData,
                          ScratchSize,
                          (VOID**)&Scratch
                          );
        }

        if (!EFI_ERROR (Status)) {
          Status = Decompress->Decompress (
                                 Decompress,
                                 CompressedData,
                                 (UINT32)CompressedDataSize,
                                 VariableData,
                                 (UINT32)BufferSize,
                                 Scratch,
                                 ScratchSize
                                 );
        }

        if (EFI_ERROR (Status)) {
          DEBUG((EFI_D_ERROR, "Getting variables error: 0x%x\n", Status));
          ASSERT (Status == EFI_SUCCESS); 
        }

        if(Scratch != NULL) {
          gBS->FreePool (Scratch);
          Scratch = NULL;
        }
      }

      if(CompressedData != NULL) {
        gBS->FreePool (CompressedData);
        CompressedData = NULL;
      }

      if ( (EFI_ERROR(Status)) || (CompareMem (HobData, VariableData, S3ChunkSize) != 0) ) {
        Status = gBS->AllocatePool (
                        EfiBootServicesData,
                        BufferSize,
                        (VOID**)&CompressedVariableData
                        );
        ASSERT (CompressedVariableData != NULL); 
        if (Status == EFI_SUCCESS) {
          CompressedBufferSize = BufferSize;
          Status = Compress(HobData, S3ChunkSize, CompressedVariableData, &CompressedBufferSize);
          if (Status == EFI_BUFFER_TOO_SMALL){
            gBS->FreePool(CompressedVariableData);
            Status = gBS->AllocatePool(
                            EfiBootServicesData,
                            CompressedBufferSize,
                            (VOID**)&CompressedVariableData
                            );
            ASSERT (CompressedVariableData != NULL);
            Status = Compress(HobData, S3ChunkSize, CompressedVariableData, &CompressedBufferSize);
          }
          if(Status == EFI_SUCCESS) {
            Status = gRT->SetVariable (
                            EfiMemoryConfigVariable,
                            &gEfiMemoryConfigDataGuid,
                            EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
                            CompressedBufferSize,
                            CompressedVariableData
                            );
          }
          if(CompressedVariableData != NULL) {
            gBS->FreePool(CompressedVariableData);
            CompressedVariableData = NULL;
          }
      }
    
        if (EFI_ERROR (Status)) {
          DEBUG((EFI_D_ERROR, "Set variable error. Status: 0x%x\n", Status));
          ASSERT_EFI_ERROR (Status);
        }
      }
      //
      // Lock the Memory Config Variable
      //
      Status = VariableLock->RequestToLock(VariableLock, EfiMemoryConfigVariable, &gEfiMemoryConfigDataGuid);
      ASSERT_EFI_ERROR(Status);
      HobData = (UINT8 *) (HobData) + S3ChunkSize;
    
      CurrentHobSize -= S3ChunkSize;
      EfiMemoryConfigVariable[12]++;  // Increment number in the string
    }
    //
    // Get next S3 Config data hob, if none left, results NULL
    //
    GuidHob = GET_NEXT_HOB (GuidHob); // Increment to next HOB
    GuidHob = GetNextGuidHob (&gEfiMemoryConfigDataHobGuid, GuidHob);  // Now search for next MemConfig HOB

    if(VariableData != NULL) {
      gBS->FreePool(VariableData);
      VariableData = NULL;
    }
  }

  return;
}

EFI_STATUS
EFIAPI
S3NvramSaveEntry ( 
  IN EFI_HANDLE                         ImageHandle,
  IN EFI_SYSTEM_TABLE                   *SystemTable
  ) 
/**

  This is the main entry point of the S3 NVRAM Save module.

  @param ImageHandle  -  Handle for the image of this driver.
  @param SystemTable  -  Pointer to the EFI System Table.

  @retval EFI_SUCCESS  -  Module launched successfully.

**/
{
  EFI_STATUS Status = EFI_SUCCESS;
  
  //
  // Save the s3 strututre from MRC into NVRAM if needed
  //
  SaveS3StructToNvram();
  
  return Status;
  
}