/** @file
  GTDT table parser

  Copyright (c) 2016 - 2024, Arm Limited. All rights reserved.
  SPDX-License-Identifier: BSD-2-Clause-Patent

  @par Reference(s):
    - ACPI 6.4 Specification - January 2021
  **/

#include <IndustryStandard/Acpi.h>
#include <Library/UefiLib.h>
#include "AcpiParser.h"
#include "AcpiTableParser.h"
#include "AcpiViewConfig.h"

// "The number of GT Block Timers must be less than or equal to 8"
#define GT_BLOCK_TIMER_COUNT_MAX  8

// Local variables
STATIC CONST UINT32                  *GtdtPlatformTimerCount;
STATIC CONST UINT32                  *GtdtPlatformTimerOffset;
STATIC CONST UINT8                   *PlatformTimerType;
STATIC CONST UINT16                  *PlatformTimerLength;
STATIC CONST UINT32                  *GtBlockTimerCount;
STATIC CONST UINT32                  *GtBlockTimerOffset;
STATIC ACPI_DESCRIPTION_HEADER_INFO  AcpiHdrInfo;

/**
  This function validates the GT Block timer count.

  @param [in] Ptr     Pointer to the start of the field data.
  @param [in] Length  Length of the field.
  @param [in] Context Pointer to context specific information e.g. this
                      could be a pointer to the ACPI table header.
**/
STATIC
VOID
EFIAPI
ValidateGtBlockTimerCount (
  IN UINT8   *Ptr,
  IN UINT32  Length,
  IN VOID    *Context
  )
{
  UINT32  BlockTimerCount;

  BlockTimerCount = *(UINT32 *)Ptr;

  if (BlockTimerCount > GT_BLOCK_TIMER_COUNT_MAX) {
    IncrementErrorCount ();
    Print (
      L"\nERROR: Timer Count = %d. Max Timer Count is %d.",
      BlockTimerCount,
      GT_BLOCK_TIMER_COUNT_MAX
      );
  }
}

/**
  This function validates the GT Frame Number.

  @param [in] Ptr     Pointer to the start of the field data.
  @param [in] Length  Length of the field.
  @param [in] Context Pointer to context specific information e.g. this
                      could be a pointer to the ACPI table header.
**/
STATIC
VOID
EFIAPI
ValidateGtFrameNumber (
  IN UINT8   *Ptr,
  IN UINT32  Length,
  IN VOID    *Context
  )
{
  UINT8  FrameNumber;

  FrameNumber = *(UINT8 *)Ptr;

  if (FrameNumber >= GT_BLOCK_TIMER_COUNT_MAX) {
    IncrementErrorCount ();
    Print (
      L"\nERROR: GT Frame Number = %d. GT Frame Number must be in range 0-%d.",
      FrameNumber,
      GT_BLOCK_TIMER_COUNT_MAX - 1
      );
  }
}

/**
  An ACPI_PARSER array describing the ACPI GTDT Table.
**/
STATIC CONST ACPI_PARSER  GtdtParser[] = {
  PARSE_ACPI_HEADER (&AcpiHdrInfo),
  { L"CntControlBase Physical Address",8,      36,  L"0x%lx", NULL, NULL,
    NULL,                             NULL },
  { L"Reserved",                      4,      44,  L"0x%x",  NULL, NULL,NULL,  NULL },
  { L"Secure EL1 timer GSIV",         4,      48,  L"0x%x",  NULL, NULL,NULL,  NULL },
  { L"Secure EL1 timer FLAGS",        4,      52,  L"0x%x",  NULL, NULL,NULL,  NULL },

  { L"Non-Secure EL1 timer GSIV",     4,      56,  L"0x%x",  NULL, NULL,NULL,  NULL },
  { L"Non-Secure EL1 timer FLAGS",    4,      60,  L"0x%x",  NULL, NULL,NULL,  NULL },

  { L"Virtual timer GSIV",            4,      64,  L"0x%x",  NULL, NULL,NULL,  NULL },
  { L"Virtual timer FLAGS",           4,      68,  L"0x%x",  NULL, NULL,NULL,  NULL },

  { L"Non-Secure EL2 timer GSIV",     4,      72,  L"0x%x",  NULL, NULL,NULL,  NULL },
  { L"Non-Secure EL2 timer FLAGS",    4,      76,  L"0x%x",  NULL, NULL,NULL,  NULL },

  { L"CntReadBase Physical address",  8,      80,  L"0x%lx", NULL, NULL,NULL,  NULL },
  { L"Platform Timer Count",          4,      88,  L"%d",    NULL,
    (VOID **)&GtdtPlatformTimerCount, NULL,   NULL },
  { L"Platform Timer Offset",         4,      92,  L"0x%x",  NULL,
    (VOID **)&GtdtPlatformTimerOffset,NULL,   NULL },
  { L"Virtual EL2 Timer GSIV",        4,      96,  L"0x%x",  NULL, NULL,NULL,  NULL },
  { L"Virtual EL2 Timer Flags",       4,      100, L"0x%x",  NULL, NULL,NULL,  NULL }
};

/**
  An ACPI_PARSER array describing the Platform timer header.
**/
STATIC CONST ACPI_PARSER  GtPlatformTimerHeaderParser[] = {
  { L"Type",     1, 0, NULL, NULL, (VOID **)&PlatformTimerType,   NULL, NULL },
  { L"Length",   2, 1, NULL, NULL, (VOID **)&PlatformTimerLength, NULL, NULL },
  { L"Reserved", 1, 3, NULL, NULL, NULL,                          NULL, NULL }
};

/**
  An ACPI_PARSER array describing the Platform GT Block.
**/
STATIC CONST ACPI_PARSER  GtBlockParser[] = {
  { L"Type",                          1, 0,  L"%d",    NULL, NULL,                         NULL, NULL },
  { L"Length",                        2, 1,  L"%d",    NULL, NULL,                         NULL, NULL },
  { L"Reserved",                      1, 3,  L"%x",    NULL, NULL,                         NULL, NULL },
  { L"Physical address (CntCtlBase)", 8, 4,  L"0x%lx", NULL, NULL,                         NULL, NULL },
  { L"Timer Count",                   4, 12, L"%d",    NULL, (VOID **)&GtBlockTimerCount,
    ValidateGtBlockTimerCount, NULL },
  { L"Timer Offset",                  4, 16, L"%d",    NULL, (VOID **)&GtBlockTimerOffset, NULL,
    NULL }
};

/**
  An ACPI_PARSER array describing the GT Block timer.
**/
STATIC CONST ACPI_PARSER  GtBlockTimerParser[] = {
  { L"Frame Number",                   1, 0,  L"%d",       NULL,       NULL, ValidateGtFrameNumber, NULL },
  { L"Reserved",                       3, 1,  L"%x %x %x", Dump3Chars, NULL, NULL,                  NULL },
  { L"Physical address (CntBaseX)",    8, 4,  L"0x%lx",    NULL,       NULL, NULL,                  NULL },
  { L"Physical address (CntEL0BaseX)", 8, 12, L"0x%lx",    NULL,       NULL, NULL,
    NULL },
  { L"Physical Timer GSIV",            4, 20, L"0x%x",     NULL,       NULL, NULL,                  NULL },
  { L"Physical Timer Flags",           4, 24, L"0x%x",     NULL,       NULL, NULL,                  NULL },
  { L"Virtual Timer GSIV",             4, 28, L"0x%x",     NULL,       NULL, NULL,                  NULL },
  { L"Virtual Timer Flags",            4, 32, L"0x%x",     NULL,       NULL, NULL,                  NULL },
  { L"Common Flags",                   4, 36, L"0x%x",     NULL,       NULL, NULL,                  NULL }
};

/**
  An ACPI_PARSER array describing the Platform Watchdog.
**/
STATIC CONST ACPI_PARSER  ArmGenericWatchdogParser[] = {
  { L"Type",                          1, 0,  L"%d",    NULL, NULL, NULL, NULL },
  { L"Length",                        2, 1,  L"%d",    NULL, NULL, NULL, NULL },
  { L"Reserved",                      1, 3,  L"%x",    NULL, NULL, NULL, NULL },
  { L"RefreshFrame Physical address", 8, 4,  L"0x%lx", NULL, NULL, NULL, NULL },
  { L"ControlFrame Physical address", 8, 12, L"0x%lx", NULL, NULL, NULL, NULL },
  { L"Watchdog Timer GSIV",           4, 20, L"0x%x",  NULL, NULL, NULL, NULL },
  { L"Watchdog Timer Flags",          4, 24, L"0x%x",  NULL, NULL, NULL, NULL }
};

/**
  This function parses the Platform GT Block.

  @param [in] Ptr       Pointer to the start of the GT Block data.
  @param [in] Length    Length of the GT Block structure.
**/
STATIC
VOID
DumpGTBlock (
  IN UINT8   *Ptr,
  IN UINT16  Length
  )
{
  UINT32  Index;
  UINT32  Offset;

  ParseAcpi (
    TRUE,
    2,
    "GT Block",
    Ptr,
    Length,
    PARSER_PARAMS (GtBlockParser)
    );

  // Check if the values used to control the parsing logic have been
  // successfully read.
  if ((GtBlockTimerCount == NULL) ||
      (GtBlockTimerOffset == NULL))
  {
    IncrementErrorCount ();
    Print (
      L"ERROR: Insufficient GT Block Structure length. Length = %d.\n",
      Length
      );
    return;
  }

  Offset = *GtBlockTimerOffset;
  Index  = 0;

  // Parse the specified number of GT Block Timer Structures or the GT Block
  // Structure buffer length. Whichever is minimum.
  while ((Index++ < *GtBlockTimerCount) &&
         (Offset < Length))
  {
    Offset += ParseAcpi (
                TRUE,
                2,
                "GT Block Timer",
                Ptr + Offset,
                Length - Offset,
                PARSER_PARAMS (GtBlockTimerParser)
                );
  }
}

/**
  This function parses the Platform Watchdog timer.

  @param [in] Ptr     Pointer to the start of the watchdog timer data.
  @param [in] Length  Length of the watchdog timer structure.
**/
STATIC
VOID
DumpWatchdogTimer (
  IN UINT8   *Ptr,
  IN UINT16  Length
  )
{
  ParseAcpi (
    TRUE,
    2,
    "Arm Generic Watchdog",
    Ptr,
    Length,
    PARSER_PARAMS (ArmGenericWatchdogParser)
    );
}

/**
  This function parses the ACPI GTDT table.
  When trace is enabled this function parses the GTDT table and
  traces the ACPI table fields.

  This function also parses the following platform timer structures:
    - GT Block timer
    - Watchdog timer

  This function also performs validation of the ACPI table fields.

  @param [in] Trace              If TRUE, trace the ACPI fields.
  @param [in] Ptr                Pointer to the start of the buffer.
  @param [in] AcpiTableLength    Length of the ACPI table.
  @param [in] AcpiTableRevision  Revision of the ACPI table.
**/
VOID
EFIAPI
ParseAcpiGtdt (
  IN BOOLEAN  Trace,
  IN UINT8    *Ptr,
  IN UINT32   AcpiTableLength,
  IN UINT8    AcpiTableRevision
  )
{
  UINT32  Index;
  UINT32  Offset;
  UINT8   *TimerPtr;

  if (!Trace) {
    return;
  }

  ParseAcpi (
    TRUE,
    0,
    "GTDT",
    Ptr,
    AcpiTableLength,
    PARSER_PARAMS (GtdtParser)
    );

  // Check if the values used to control the parsing logic have been
  // successfully read.
  if ((GtdtPlatformTimerCount == NULL) ||
      (GtdtPlatformTimerOffset == NULL))
  {
    IncrementErrorCount ();
    Print (
      L"ERROR: Insufficient table length. AcpiTableLength = %d.\n",
      AcpiTableLength
      );
    return;
  }

  TimerPtr = Ptr + *GtdtPlatformTimerOffset;
  Offset   = *GtdtPlatformTimerOffset;
  Index    = 0;

  // Parse the specified number of Platform Timer Structures or the GTDT
  // buffer length. Whichever is minimum.
  while ((Index++ < *GtdtPlatformTimerCount) &&
         (Offset < AcpiTableLength))
  {
    // Parse the Platform Timer Header to obtain Length and Type
    ParseAcpi (
      FALSE,
      0,
      NULL,
      TimerPtr,
      AcpiTableLength - Offset,
      PARSER_PARAMS (GtPlatformTimerHeaderParser)
      );

    // Check if the values used to control the parsing logic have been
    // successfully read.
    if ((PlatformTimerType == NULL) ||
        (PlatformTimerLength == NULL))
    {
      IncrementErrorCount ();
      Print (
        L"ERROR: Insufficient remaining table buffer length to read the " \
        L"Platform Timer Structure header. Length = %d.\n",
        AcpiTableLength - Offset
        );
      return;
    }

    // Validate Platform Timer Structure length
    if ((*PlatformTimerLength == 0) ||
        ((Offset + (*PlatformTimerLength)) > AcpiTableLength))
    {
      IncrementErrorCount ();
      Print (
        L"ERROR: Invalid Platform Timer Structure length. " \
        L"Length = %d. Offset = %d. AcpiTableLength = %d.\n",
        *PlatformTimerLength,
        Offset,
        AcpiTableLength
        );
      return;
    }

    switch (*PlatformTimerType) {
      case EFI_ACPI_6_4_GTDT_GT_BLOCK:
        DumpGTBlock (TimerPtr, *PlatformTimerLength);
        break;
      case EFI_ACPI_6_4_GTDT_ARM_GENERIC_WATCHDOG:
        DumpWatchdogTimer (TimerPtr, *PlatformTimerLength);
        break;
      default:
        IncrementErrorCount ();
        Print (
          L"ERROR: Invalid Platform Timer Type = %d\n",
          *PlatformTimerType
          );
        break;
    } // switch

    TimerPtr += *PlatformTimerLength;
    Offset   += *PlatformTimerLength;
  } // while
}