/** @file
  PCCT table parser

  Copyright (c) 2021 - 2024, Arm Limited. All rights reserved.
  SPDX-License-Identifier: BSD-2-Clause-Patent

  @par Reference(s):
    - ACPI 6.4 Specification - January 2021
**/

#include <Library/BaseMemoryLib.h>
#include <Library/PrintLib.h>
#include <Library/UefiLib.h>
#include "AcpiParser.h"
#include "AcpiView.h"
#include "AcpiViewConfig.h"
#include "PcctParser.h"

// Local variables
STATIC ACPI_DESCRIPTION_HEADER_INFO  AcpiHdrInfo;

STATIC UINT32  *PccGlobalFlags;
STATIC UINT8   *PccSubspaceLength;
STATIC UINT8   *PccSubspaceType;
STATIC UINT8   *ExtendedPccSubspaceInterruptFlags;

/**
  This function validates the length coded on 4 bytes of a shared memory range

  @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
ValidateRangeLength4 (
  IN UINT8   *Ptr,
  IN UINT32  Length,
  IN VOID    *Context
  )
{
  if (*(UINT32 *)Ptr < MIN_EXT_PCC_SUBSPACE_MEM_RANGE_LEN) {
    IncrementErrorCount ();
    Print (
      L"\nError: Shared memory range length is too short.\n"
      L"Length is %u when it should be greater than or equal to %u",
      *(UINT32 *)Ptr,
      MIN_EXT_PCC_SUBSPACE_MEM_RANGE_LEN
      );
  }
}

/**
  This function validates the length coded on 8 bytes of a shared memory range

  @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
ValidateRangeLength8 (
  IN UINT8   *Ptr,
  IN UINT32  Length,
  IN VOID    *Context
  )
{
  if (*(UINT64 *)Ptr <= MIN_MEMORY_RANGE_LENGTH) {
    IncrementErrorCount ();
    Print (
      L"\nError: Shared memory range length is too short.\n"
      L"Length is %u when it should be greater than %u",
      *(UINT64 *)Ptr,
      MIN_MEMORY_RANGE_LENGTH
      );
  }
}

/**
  This function validates address space for Memory/IO GAS.

  @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
ValidatePccMemoryIoGas (
  IN UINT8   *Ptr,
  IN UINT32  Length,
  IN VOID    *Context
  )
{
  switch (*(UINT8 *)Ptr) {
 #if !(defined (MDE_CPU_ARM) || defined (MDE_CPU_AARCH64))
    case EFI_ACPI_6_4_SYSTEM_IO:
 #endif //if not (defined (MDE_CPU_ARM) || defined (MDE_CPU_AARCH64))
    case EFI_ACPI_6_4_SYSTEM_MEMORY:
      return;
    default:
      IncrementErrorCount ();
      Print (L"\nError: Invalid address space");
  }
}

/**
  This function validates address space for structures of types other than 0.

  @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
ValidatePccGas (
  IN UINT8   *Ptr,
  IN UINT32  Length,
  IN VOID    *Context
  )
{
  switch (*(UINT8 *)Ptr) {
 #if !(defined (MDE_CPU_ARM) || defined (MDE_CPU_AARCH64))
    case EFI_ACPI_6_4_SYSTEM_IO:
 #endif //if not (defined (MDE_CPU_ARM) || defined (MDE_CPU_AARCH64))
    case EFI_ACPI_6_4_FUNCTIONAL_FIXED_HARDWARE:
    case EFI_ACPI_6_4_SYSTEM_MEMORY:
      return;
    default:
      IncrementErrorCount ();
      Print (L"\nError: Invalid address space");
  }
}

/**
  This function validates doorbell address space for type 4 structure.

  @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
ValidatePccDoorbellGas (
  IN UINT8   *Ptr,
  IN UINT32  Length,
  IN VOID    *Context
  )
{
  // For responder subspaces this field is optional, if not present the field
  // should just contain zeros.
  if (*PccSubspaceType == EFI_ACPI_6_4_PCCT_SUBSPACE_TYPE_4_EXTENDED_PCC) {
    if (IsZeroBuffer (
          Ptr,
          sizeof (EFI_ACPI_6_4_GENERIC_ADDRESS_STRUCTURE)
          ))
    {
      return;
    }
  }

  ValidatePccGas (Ptr, Length, Context);
}

/**
  This function validates interrupt acknowledge address space for
  type 4 structure.

  @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
ValidatePccIntAckGas (
  IN UINT8   *Ptr,
  IN UINT32  Length,
  IN VOID    *Context
  )
{
  // If the subspace does not support interrupts or the interrupt is
  // edge driven the register may be omitted. A value of 0x0 on all
  // 12 bytes of the GAS structure indicates the register is not
  // present.
  if (((*PccGlobalFlags & EFI_ACPI_6_4_PCCT_FLAGS_PLATFORM_INTERRUPT) !=
       EFI_ACPI_6_4_PCCT_FLAGS_PLATFORM_INTERRUPT) ||
      ((*ExtendedPccSubspaceInterruptFlags &
        EFI_ACPI_6_4_PCCT_SUBSPACE_PLATFORM_INTERRUPT_FLAGS_MODE) ==
       EFI_ACPI_6_4_PCCT_SUBSPACE_PLATFORM_INTERRUPT_FLAGS_MODE))
  {
    if (IsZeroBuffer (
          Ptr,
          sizeof (EFI_ACPI_6_4_GENERIC_ADDRESS_STRUCTURE)
          ))
    {
      return;
    }
  }

  ValidatePccGas (Ptr, Length, Context);
}

/**
  This function validates error status address space for type 4 structure.

  @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
ValidatePccErrStatusGas (
  IN UINT8   *Ptr,
  IN UINT32  Length,
  IN VOID    *Context
  )
{
  // This field is ignored by the OSPM on responder channels.
  if (*PccSubspaceType == EFI_ACPI_6_4_PCCT_SUBSPACE_TYPE_4_EXTENDED_PCC) {
    return;
  }

  ValidatePccGas (Ptr, Length, Context);
}

/**
  This function validates platform interrupt flags for type 4 structure.

  @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
ValidatePlatInterrupt (
  IN UINT8   *Ptr,
  IN UINT32  Length,
  IN VOID    *Context
  )
{
  // If a responder subspace is present in the PCCT, then the global Platform
  // Interrupt flag must be set to 1.
  if ((*PccSubspaceType == EFI_ACPI_6_4_PCCT_SUBSPACE_TYPE_4_EXTENDED_PCC) &&
      ((*PccGlobalFlags & EFI_ACPI_6_4_PCCT_FLAGS_PLATFORM_INTERRUPT) !=
       EFI_ACPI_6_4_PCCT_FLAGS_PLATFORM_INTERRUPT))
  {
    IncrementErrorCount ();
    Print (
      L"\nError: Global Platform interrupt flag must be set to 1" \
      L" if a PCC type 4 structure is present in PCCT."
      );
  }
}

/**
  An ACPI_PARSER array describing the ACPI PCCT Table.
*/
STATIC CONST ACPI_PARSER  PcctParser[] = {
  PARSE_ACPI_HEADER (&AcpiHdrInfo),
  { L"Flags",                      4,  36, NULL, NULL, (VOID **)&PccGlobalFlags, NULL, NULL },
  { L"Reserved",                   8,  40, NULL, NULL, NULL,                     NULL, NULL }
};

/**
  An ACPI_PARSER array describing the platform communications channel subspace
  structure header.
*/
STATIC CONST ACPI_PARSER  PccSubspaceHeaderParser[] = {
  PCC_SUBSPACE_HEADER ()
  // ... Type Specific Fields ...
};

/**
  An ACPI_PARSER array describing the Generic Communications Subspace - Type 0
*/
STATIC CONST ACPI_PARSER  PccSubspaceType0Parser[] = {
  PCC_SUBSPACE_HEADER (),
  { L"Reserved",         6,   2,  L"%x %x %x %x %x %x", Dump6Chars, NULL, NULL,                   NULL },
  { L"Base Address",     8,   8,  L"0x%lx",             NULL,       NULL, NULL,                   NULL },
  { L"Memory Range Length",8,   16, L"0x%lx",             NULL,       NULL, ValidateRangeLength8,
    NULL },
  { L"Doorbell Register",12,  24, NULL,                 DumpGas,    NULL, ValidatePccMemoryIoGas,
    NULL },
  { L"Doorbell Preserve",8,   36, L"0x%lx",             NULL,       NULL, NULL,                   NULL },
  { L"Doorbell Write",   8,   44, L"0x%lx",             NULL,       NULL, NULL,                   NULL },
  { L"Nominal Latency",  4,   52, L"%u",                NULL,       NULL, NULL,                   NULL },
  { L"Maximum Periodic Access Rate",4,   56, L"%u",                NULL,       NULL, NULL,                   NULL },
  { L"Minimum Request Turnaround Time",2,   60, L"%u",                NULL,       NULL, NULL,                   NULL }
};

/**
  An ACPI_PARSER array describing the HW-Reduced Communications Subspace
  - Type 1
*/
STATIC CONST ACPI_PARSER  PccSubspaceType1Parser[] = {
  PCC_SUBSPACE_HEADER (),
  { L"Platform Interrupt",4,   2,  L"0x%x",  NULL,    NULL, NULL,                 NULL },
  { L"Platform Interrupt Flags",1,   6,  L"0x%x",  NULL,    NULL, NULL,                 NULL },
  { L"Reserved",         1,   7,  L"0x%x",  NULL,    NULL, NULL,                 NULL },
  { L"Base Address",     8,   8,  L"0x%lx", NULL,    NULL, NULL,                 NULL },
  { L"Memory Range Length",8,   16, L"0x%lx", NULL,    NULL, ValidateRangeLength8,
    NULL },
  { L"Doorbell Register",12,  24, NULL,     DumpGas, NULL,
    ValidatePccGas,      NULL },
  { L"Doorbell Preserve",8,   36, L"0x%lx", NULL,    NULL, NULL,                 NULL },
  { L"Doorbell Write",   8,   44, L"0x%lx", NULL,    NULL, NULL,                 NULL },
  { L"Nominal Latency",  4,   52, L"%u",    NULL,    NULL, NULL,                 NULL },
  { L"Maximum Periodic Access Rate",4,   56, L"%u",    NULL,    NULL, NULL,                 NULL },
  { L"Minimum Request Turnaround Time",2,   60, L"%u",    NULL,    NULL, NULL,                 NULL }
};

/**
  An ACPI_PARSER array describing the HW-Reduced Communications Subspace
  - Type 2
*/
STATIC CONST ACPI_PARSER  PccSubspaceType2Parser[] = {
  PCC_SUBSPACE_HEADER (),
  { L"Platform Interrupt",4,   2,  L"0x%x",  NULL,    NULL, NULL,                 NULL },
  { L"Platform Interrupt Flags",1,   6,  L"0x%x",  NULL,    NULL, NULL,                 NULL },
  { L"Reserved",         1,   7,  L"0x%x",  NULL,    NULL, NULL,                 NULL },
  { L"Base Address",     8,   8,  L"0x%lx", NULL,    NULL, NULL,                 NULL },
  { L"Memory Range Length",8,   16, L"0x%lx", NULL,    NULL, ValidateRangeLength8,
    NULL },
  { L"Doorbell Register",12,  24, NULL,     DumpGas, NULL,
    ValidatePccGas,      NULL },
  { L"Doorbell Preserve",8,   36, L"0x%lx", NULL,    NULL, NULL,                 NULL },
  { L"Doorbell Write",   8,   44, L"0x%lx", NULL,    NULL, NULL,                 NULL },
  { L"Nominal Latency",  4,   52, L"%u",    NULL,    NULL, NULL,                 NULL },
  { L"Maximum Periodic Access Rate",4,   56, L"%u",    NULL,    NULL, NULL,                 NULL },
  { L"Minimum Request Turnaround Time",2,   60, L"%u",    NULL,    NULL, NULL,                 NULL },
  { L"Platform Interrupt Ack Register",12,  62, NULL,     DumpGas, NULL,
    ValidatePccGas,      NULL },
  { L"Platform Interrupt Ack Preserve",8,   74, L"0x%lx", NULL,    NULL, NULL,                 NULL },
  { L"Platform Interrupt Ack Write",8,   82, L"0x%lx", NULL,    NULL,
    NULL,                NULL },
};

/**
  An ACPI_PARSER array describing the Extended PCC Subspaces - Type 3/4
*/
STATIC CONST ACPI_PARSER  PccSubspaceType3Parser[] = {
  PCC_SUBSPACE_HEADER (),
  { L"Platform Interrupt",                      4,     2,   L"0x%x",  NULL,    NULL,
    ValidatePlatInterrupt,                      NULL },
  { L"Platform Interrupt Flags",                1,     6,   L"0x%x",  NULL,
    (VOID **)&ExtendedPccSubspaceInterruptFlags,NULL,  NULL },
  { L"Reserved",                                1,     7,   L"0x%x",  NULL,    NULL,NULL,                  NULL },
  { L"Base Address",                            8,     8,   L"0x%lx", NULL,    NULL,NULL,                  NULL },
  { L"Memory Range Length",                     4,     16,  L"0x%x",  NULL,    NULL,ValidateRangeLength4,
    NULL },
  { L"Doorbell Register",                       12,    20,  NULL,     DumpGas, NULL,
    ValidatePccDoorbellGas,                     NULL },
  { L"Doorbell Preserve",                       8,     32,  L"0x%lx", NULL,    NULL,NULL,                  NULL },
  { L"Doorbell Write",                          8,     40,  L"0x%lx", NULL,    NULL,NULL,                  NULL },
  { L"Nominal Latency",                         4,     48,  L"%u",    NULL,    NULL,NULL,                  NULL },
  { L"Maximum Periodic Access Rate",            4,     52,  L"%u",    NULL,    NULL,NULL,                  NULL },
  { L"Minimum Request Turnaround Time",         4,     56,  L"%u",    NULL,    NULL,NULL,                  NULL },
  { L"Platform Interrupt Ack Register",         12,    60,  NULL,     DumpGas, NULL,
    ValidatePccIntAckGas,                       NULL },
  { L"Platform Interrupt Ack Preserve",         8,     72,  L"0x%lx", NULL,    NULL,NULL,                  NULL },
  { L"Platform Interrupt Ack Set",              8,     80,  L"0x%lx", NULL,    NULL,NULL,                  NULL },
  { L"Reserved",                                8,     88,  L"0x%lx", NULL,    NULL,NULL,                  NULL },
  { L"Cmd Complete Check Reg Addr",             12,    96,  NULL,     DumpGas, NULL,
    ValidatePccGas,                             NULL },
  { L"Cmd Complete Check Mask",                 8,     108, L"0x%lx", NULL,    NULL,NULL,                  NULL },
  { L"Cmd Update Reg Addr",                     12,    116, NULL,     DumpGas, NULL,
    ValidatePccGas,                             NULL },
  { L"Cmd Update Preserve mask",                8,     128, L"0x%lx", NULL,    NULL,NULL,                  NULL },
  { L"Cmd Update Set mask",                     8,     136, L"0x%lx", NULL,    NULL,NULL,                  NULL },
  { L"Error Status Register",                   12,    144, NULL,     DumpGas, NULL,
    ValidatePccErrStatusGas,                    NULL },
  { L"Error Status Mask",                       8,     156, L"0x%lx", NULL,    NULL,NULL,                  NULL },
};

/**
  An ACPI_PARSER array describing the HW Registers based Communications
  Subspace Structure - Type 5
*/
STATIC CONST ACPI_PARSER  PccSubspaceType5Parser[] = {
  PCC_SUBSPACE_HEADER (),
  { L"Version",            2,   2,  L"0x%x",  NULL,    NULL, NULL, NULL },
  { L"Base Address",       8,   4,  L"0x%lx", NULL,    NULL, NULL, NULL },
  { L"Shared Memory Range Length",8,   12, L"0x%lx", NULL,    NULL, NULL, NULL },
  { L"Doorbell Register",  12,  20, NULL,     DumpGas, NULL,
    ValidatePccMemoryIoGas,NULL },
  { L"Doorbell Preserve",  8,   32, L"0x%lx", NULL,    NULL, NULL, NULL },
  { L"Doorbell Write",     8,   40, L"0x%lx", NULL,    NULL, NULL, NULL },
  { L"Command Complete Check Register",12,  48, NULL,     DumpGas, NULL,
    ValidatePccMemoryIoGas,NULL },
  { L"Command Complete Check Mask",8,   60, L"0x%lx", NULL,    NULL, NULL, NULL },
  { L"Error Status Register",12,  68, NULL,     DumpGas, NULL,
    ValidatePccMemoryIoGas,NULL },
  { L"Error Status Mask",  8,   80, L"0x%lx", NULL,    NULL, NULL, NULL },
  { L"Nominal Latency",    4,   88, L"0x%x",  NULL,    NULL, NULL, NULL },
  { L"Minimum Request Turnaround Time",4,   92, L"0x%x",  NULL,    NULL, NULL, NULL }
};

/**
  This function parses the PCC Subspace type 0.

  @param [in] Ptr     Pointer to the start of Subspace Structure.
  @param [in] Length  Length of the Subspace Structure.
**/
STATIC
VOID
DumpPccSubspaceType0 (
  IN UINT8  *Ptr,
  IN UINT8  Length
  )
{
  ParseAcpi (
    TRUE,
    2,
    "Subspace Type 0",
    Ptr,
    Length,
    PARSER_PARAMS (PccSubspaceType0Parser)
    );
}

/**
  This function parses the PCC Subspace type 1.

  @param [in] Ptr     Pointer to the start of the Subspace Structure.
  @param [in] Length  Length of the Subspace Structure.
**/
STATIC
VOID
DumpPccSubspaceType1 (
  IN UINT8  *Ptr,
  IN UINT8  Length
  )
{
  ParseAcpi (
    TRUE,
    2,
    "Subspace Type 1",
    Ptr,
    Length,
    PARSER_PARAMS (PccSubspaceType1Parser)
    );
}

/**
  This function parses the PCC Subspace type 2.

  @param [in] Ptr     Pointer to the start of the Subspace Structure.
  @param [in] Length  Length of the Subspace Structure.
**/
STATIC
VOID
DumpPccSubspaceType2 (
  IN UINT8  *Ptr,
  IN UINT8  Length
  )
{
  ParseAcpi (
    TRUE,
    2,
    "Subspace Type 2",
    Ptr,
    Length,
    PARSER_PARAMS (PccSubspaceType2Parser)
    );
}

/**
  This function parses the PCC Subspace type 3.

  @param [in] Ptr     Pointer to the start of the Subspace Structure.
  @param [in] Length  Length of the Subspace Structure.
**/
STATIC
VOID
DumpPccSubspaceType3 (
  IN UINT8  *Ptr,
  IN UINT8  Length
  )
{
  ParseAcpi (
    TRUE,
    2,
    "Subspace Type 3",
    Ptr,
    Length,
    PARSER_PARAMS (PccSubspaceType3Parser)
    );
}

/**
  This function parses the PCC Subspace type 4.

  @param [in] Ptr     Pointer to the start of the Subspace Structure.
  @param [in] Length  Length of the Subspace Structure.
**/
STATIC
VOID
DumpPccSubspaceType4 (
  IN UINT8  *Ptr,
  IN UINT8  Length
  )
{
  ParseAcpi (
    TRUE,
    2,
    "Subspace Type 4",
    Ptr,
    Length,
    PARSER_PARAMS (PccSubspaceType3Parser)
    );
}

/**
  This function parses the PCC Subspace type 5.

  @param [in] Ptr     Pointer to the start of the Subspace Structure.
  @param [in] Length  Length of the Subspace Structure.
**/
STATIC
VOID
DumpPccSubspaceType5 (
  IN UINT8  *Ptr,
  IN UINT8  Length
  )
{
  ParseAcpi (
    TRUE,
    2,
    "Subspace Type 5",
    Ptr,
    Length,
    PARSER_PARAMS (PccSubspaceType5Parser)
    );
}

/**
  This function parses the ACPI PCCT table including its sub-structures
  of type 0 through 4.
  When trace is enabled this function parses the PCCT table and
  traces the ACPI table fields.

  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
ParseAcpiPcct (
  IN BOOLEAN  Trace,
  IN UINT8    *Ptr,
  IN UINT32   AcpiTableLength,
  IN UINT8    AcpiTableRevision
  )
{
  UINT32  Offset;
  UINT8   *PccSubspacePtr;
  UINTN   SubspaceCount;

  if (!Trace) {
    return;
  }

  Offset = ParseAcpi (
             TRUE,
             0,
             "PCCT",
             Ptr,
             AcpiTableLength,
             PARSER_PARAMS (PcctParser)
             );

  PccSubspacePtr = Ptr + Offset;

  SubspaceCount = 0;
  while (Offset < AcpiTableLength) {
    // Parse common structure header to obtain Type and Length.
    ParseAcpi (
      FALSE,
      0,
      NULL,
      PccSubspacePtr,
      AcpiTableLength - Offset,
      PARSER_PARAMS (PccSubspaceHeaderParser)
      );

    // Check if the values used to control the parsing logic have been
    // successfully read.
    if ((PccSubspaceType == NULL) ||
        (PccSubspaceLength == NULL))
    {
      IncrementErrorCount ();
      Print (
        L"ERROR: Insufficient remaining table buffer length to read the " \
        L"structure header. Length = %u.\n",
        AcpiTableLength - Offset
        );
      return;
    }

    // Validate Structure length
    if ((*PccSubspaceLength == 0) ||
        ((Offset + (*PccSubspaceLength)) > AcpiTableLength))
    {
      IncrementErrorCount ();
      Print (
        L"ERROR: Invalid Structure length. " \
        L"Length = %u. Offset = %u. AcpiTableLength = %u.\n",
        *PccSubspaceLength,
        Offset,
        AcpiTableLength
        );
      return;
    }

    switch (*PccSubspaceType) {
      case EFI_ACPI_6_4_PCCT_SUBSPACE_TYPE_GENERIC:
        DumpPccSubspaceType0 (
          PccSubspacePtr,
          *PccSubspaceLength
          );
        break;
      case EFI_ACPI_6_4_PCCT_SUBSPACE_TYPE_1_HW_REDUCED_COMMUNICATIONS:
        DumpPccSubspaceType1 (
          PccSubspacePtr,
          *PccSubspaceLength
          );
        break;
      case EFI_ACPI_6_4_PCCT_SUBSPACE_TYPE_2_HW_REDUCED_COMMUNICATIONS:
        DumpPccSubspaceType2 (
          PccSubspacePtr,
          *PccSubspaceLength
          );
        break;
      case EFI_ACPI_6_4_PCCT_SUBSPACE_TYPE_3_EXTENDED_PCC:
        DumpPccSubspaceType3 (
          PccSubspacePtr,
          *PccSubspaceLength
          );
        break;
      case EFI_ACPI_6_4_PCCT_SUBSPACE_TYPE_4_EXTENDED_PCC:
        DumpPccSubspaceType4 (
          PccSubspacePtr,
          *PccSubspaceLength
          );
        break;
      case EFI_ACPI_6_4_PCCT_SUBSPACE_TYPE_5_HW_REGISTERS_COMMUNICATIONS:
        DumpPccSubspaceType5 (
          PccSubspacePtr,
          *PccSubspaceLength
          );
        break;
      default:
        IncrementErrorCount ();
        Print (
          L"ERROR: Unknown PCC subspace structure:"
          L" Type = %u, Length = %u\n",
          PccSubspaceType,
          *PccSubspaceLength
          );
    }

    PccSubspacePtr += *PccSubspaceLength;
    Offset         += *PccSubspaceLength;
    SubspaceCount++;
  } // while

  if (SubspaceCount > MAX_PCC_SUBSPACES) {
    IncrementErrorCount ();
    Print (L"ERROR: Too many PCC subspaces.");
  }
}