Re: [edk2-devel] [PATCH v1 1/4] ShellPkg: acpiview: Improve PPTT table field validation

["Krzysztof Koch" <krzysztof.koch@arm.com>]

Hi Zhichao,

Thank you for the review. You can see my responses in line with your comments marked with [Krzysztof]

Kind regards,

Krzysztof

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Gao, Zhichao via Groups.Io
Sent: Monday, July 1, 2019 4:49
To: Krzysztof Koch <Krzysztof.Koch@arm.com>; devel@edk2.groups.io
Cc: Carsey, Jaben <jaben.carsey@intel.com>; Ni, Ray <ray.ni@intel.com>; Sami Mujawar <Sami.Mujawar@arm.com>; Matteo Carlini <Matteo.Carlini@arm.com>; nd <nd@arm.com>
Subject: Re: [edk2-devel] [PATCH v1 1/4] ShellPkg: acpiview: Improve PPTT table field validation

Minor comment on ValidateCacheAssociativity:

> -----Original Message-----
> From: Krzysztof Koch [mailto:krzysztof.koch@arm.com]
> Sent: Friday, June 28, 2019 6:25 PM
> To: devel@edk2.groups.io
> Cc: Carsey, Jaben <jaben.carsey@intel.com>; Ni, Ray 
> <ray.ni@intel.com>; Gao, Zhichao <zhichao.gao@intel.com>; 
> Sami.Mujawar@arm.com; Matteo.Carlini@arm.com; nd@arm.com
> Subject: [PATCH v1 1/4] ShellPkg: acpiview: Improve PPTT table field 
> validation
> 
> Add Cache Structure (Type 1) 'Number of sets' and 'Associativity'
> field validation in the acpiview Processor Properties Topology Table 
> (PPTT) parser.
> 
> Replace literal values with precompiler macros for existing Cache 
> Structure validation functions.
> 
> Signed-off-by: Krzysztof Koch <krzysztof.koch@arm.com>
> ---
> 
> Changes can be seen at:
> https://github.com/KrzysztofKoch1/edk2/commit/014f98b8f1ba29607d8d46
> 5cac779badc3c79982
> 
> Notes:
>     v1:
>     - Use macros to define constant values used for validation [Krzysztof]
>     - Add two new PPTT Type 1 structure validation functions 
> [Krzysztof]
> 
>
> ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Pptt/PpttParser.c
> | 102 ++++++++++++++++++--
> ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Pptt/PpttParser.h
> |  38 ++++++++
>  2 files changed, 130 insertions(+), 10 deletions(-)
> 
> diff --git
> a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Pptt/PpttParser.
> c
> b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Pptt/PpttParser.
> c
> index
> 71b6e7ae7c727ee0ea12f74e60c27c4c46e05872..cec57be55e77096f9448f637e
> a129af2b42111ad 100644
> ---
> a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Pptt/PpttParser.
> c
> +++
> b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Pptt/PpttPars
> +++ er.c
> @@ -5,12 +5,15 @@
>    SPDX-License-Identifier: BSD-2-Clause-Patent
> 
>    @par Reference(s):
> -    - ACPI 6.2 Specification - Errata A, September 2017
> +    - ACPI 6.3 Specification - January 2019
> +    - ARM Architecture Reference Manual ARMv8 (D.a)
>  **/
> 
>  #include <Library/PrintLib.h>
>  #include <Library/UefiLib.h>
>  #include "AcpiParser.h"
> +#include "AcpiView.h"
> +#include "PpttParser.h"
> 
>  // Local variables
>  STATIC CONST UINT8*  ProcessorTopologyStructureType; @@ -19,11 +22,80 
> @@ STATIC CONST UINT32* NumberOfPrivateResources;  STATIC 
> ACPI_DESCRIPTION_HEADER_INFO AcpiHdrInfo;
> 
>  /**
> -  An ACPI_PARSER array describing the ACPI PPTT Table.
> +  This function validates the Cache Type Structure (Type 1) 'Number of sets'
> +  field.
> +
> +  @param [in] Ptr       Pointer to the start of the field data.
> +  @param [in] Context   Pointer to context specific information e.g. this
> +                        could be a pointer to the ACPI table header.
>  **/
> -STATIC CONST ACPI_PARSER PpttParser[] = {
> -  PARSE_ACPI_HEADER (&AcpiHdrInfo)
> -};
> +STATIC
> +VOID
> +EFIAPI
> +ValidateCacheNumberOfSets (
> +  IN UINT8* Ptr,
> +  IN VOID*  Context
> +  )
> +{
> +  UINT32 NumberOfSets;
> +  NumberOfSets = *(UINT32*)Ptr;
> +
> +  if (NumberOfSets == 0) {
> +    IncrementErrorCount ();
> +    Print (L"\nERROR: Cache number of sets must be greater than 0");
> +    return;
> +  }
> +
> +#if defined(MDE_CPU_ARM) || defined (MDE_CPU_AARCH64)
> +  if (NumberOfSets > PPTT_ARM_CCIDX_CACHE_NUMBER_OF_SETS_MAX)
> {
> +    IncrementErrorCount ();
> +    Print (
> +      L"\nERROR: When ARMv8.3-CCIDX is implemented the maximum cache
> number of "
> +        L"sets must be less than or equal to %d",
> +      PPTT_ARM_CCIDX_CACHE_NUMBER_OF_SETS_MAX
> +      );
> +    return;
> +  }
> +
> +  if (NumberOfSets > PPTT_ARM_CACHE_NUMBER_OF_SETS_MAX) {
> +    IncrementWarningCount ();
> +    Print (
> +      L"\nWARNING: Without ARMv8.3-CCIDX, the maximum cache number
> of sets "
> +        L"must be less than or equal to %d. Ignore this message if "
> +        L"ARMv8.3-CCIDX is implemented",
> +      PPTT_ARM_CACHE_NUMBER_OF_SETS_MAX
> +      );
> +    return;
> +  }
> +#endif
> +
> +}
> +
> +/**
> +  This function validates the Cache Type Structure (Type 1) 'Associativity'
> +  field.
> +
> +  @param [in] Ptr       Pointer to the start of the field data.
> +  @param [in] Context   Pointer to context specific information e.g. this
> +                        could be a pointer to the ACPI table header.
> +**/
> +STATIC
> +VOID
> +EFIAPI
> +ValidateCacheAssociativity (
> +  IN UINT8* Ptr,
> +  IN VOID*  Context
> +  )
> +{
> +  UINT8 Associativity;
> +  Associativity = *(UINT8*)Ptr;
> +
> +  if (Associativity == 0) {
> +    IncrementErrorCount ();
> +    Print (L"\nERROR: Cache associativity must be greater than 0");
> +    return;
> +  }
> +}

I see you add the PPTT_ARM_CCIDX_CACHE_ASSOCIATIVITY_MAX  and PPTT_ARM_CACHE_ASSOCIATIVITY_MAX but they are not include in ValidateCacheAssociativity.
Is this a missing?

Thanks,
Zhichao

[Krzysztof] I added PPTT_ARM_CCIDX_CACHE_ASSOCIATIVITY_MAX  and PPTT_ARM_CACHE_ASSOCIATIVITY_MAX to entirely cover Arm architecture. However, the Associativity field in PPTT Type 1 structure is only one byte long, therefore, values of 2^10 or 2^21 will never be reached.

These macros are not used as of now, but I think that this table field is likely to get expanded in the future and PPTT_ARM_CCIDX_CACHE_ASSOCIATIVITY_MAX  and PPTT_ARM_CACHE_ASSOCIATIVITY_MAX will become valid checks.

> 
>  /**
>    This function validates the Cache Type Structure (Type 1) Line size field.
> @@ -49,11 +121,14 @@ ValidateCacheLineSize (
>    UINT16 LineSize;
>    LineSize = *(UINT16*)Ptr;
> 
> -  if ((LineSize < 16) || (LineSize > 2048)) {
> +  if ((LineSize < PPTT_ARM_CACHE_LINE_SIZE_MIN) ||
> +      (LineSize > PPTT_ARM_CACHE_LINE_SIZE_MAX)) {
>      IncrementErrorCount ();
>      Print (
> -      L"\nERROR: The cache line size must be between 16 and 2048 bytes"
> -        L" on ARM Platforms."
> +      L"\nERROR: The cache line size must be between %d and %d bytes"
> +        L" on ARM Platforms.",
> +      PPTT_ARM_CACHE_LINE_SIZE_MIN,
> +      PPTT_ARM_CACHE_LINE_SIZE_MAX
>        );
>      return;
>    }
> @@ -96,6 +171,13 @@ ValidateCacheAttributes (
>    }
>  }
> 
> +/**
> +  An ACPI_PARSER array describing the ACPI PPTT Table.
> +**/
> +STATIC CONST ACPI_PARSER PpttParser[] = {
> +  PARSE_ACPI_HEADER (&AcpiHdrInfo)
> +};
> +
>  /**
>    An ACPI_PARSER array describing the processor topology structure header.
>  **/
> @@ -133,8 +215,8 @@ STATIC CONST ACPI_PARSER 
> CacheTypeStructureParser[] = {
>    {L"Flags", 4, 4, L"0x%x", NULL, NULL, NULL, NULL},
>    {L"Next Level of Cache", 4, 8, L"0x%x", NULL, NULL, NULL, NULL},
>    {L"Size", 4, 12, L"0x%x", NULL, NULL, NULL, NULL},
> -  {L"Number of sets", 4, 16, L"%d", NULL, NULL, NULL, NULL},
> -  {L"Associativity", 1, 20, L"%d", NULL, NULL, NULL, NULL},
> +  {L"Number of sets", 4, 16, L"%d", NULL, NULL, 
> + ValidateCacheNumberOfSets, NULL},  {L"Associativity", 1, 20, L"%d", 
> + NULL, NULL, ValidateCacheAssociativity, NULL},
>    {L"Attributes", 1, 21, L"0x%x", NULL, NULL, ValidateCacheAttributes, NULL},
>    {L"Line size", 2, 22, L"%d", NULL, NULL, ValidateCacheLineSize, 
> NULL}  }; diff --git 
> a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Pptt/PpttParser.
> h
> b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Pptt/PpttParser.
> h
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..2a671203fb0035bbc407ff4bb0
> ca9960706fa588
> --- /dev/null
> +++
> b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Pptt/PpttPars
> +++ er.h
> @@ -0,0 +1,38 @@
> +/** @file
> +  Header file for PPTT parser
> +
> +  Copyright (c) 2019, ARM Limited. All rights reserved.
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +  @par Reference(s):
> +    - ARM Architecture Reference Manual ARMv8 (D.a) **/
> +
> +#ifndef PPTT_PARSER_H_
> +#define PPTT_PARSER_H_
> +
> +#if defined (MDE_CPU_ARM) || defined (MDE_CPU_AARCH64)
> +
> +/// Cache parameters allowed by the architecture with /// 
> +ARMv8.3-CCIDX (Cache extended number of sets) /// Derived from 
> +CCSIDR_EL1 when
> +ID_AA64MMFR2_EL1.CCIDX==0001
> +#define PPTT_ARM_CCIDX_CACHE_NUMBER_OF_SETS_MAX       (1 << 24)
> +#define PPTT_ARM_CCIDX_CACHE_ASSOCIATIVITY_MAX        (1 << 21)
> +
> +/// Cache parameters allowed by the architecture without /// 
> +ARMv8.3-CCIDX (Cache extended number of sets) /// Derived from
> +CCSIDR_EL1 when ID_AA64MMFR2_EL1.CCIDX==0000
> +#define PPTT_ARM_CACHE_NUMBER_OF_SETS_MAX             (1 << 15)
> +#define PPTT_ARM_CACHE_ASSOCIATIVITY_MAX              (1 << 10)
> +
> +/// Common cache parameters
> +/// Derived from CCSIDR_EL1
> +/// The LineSize is represented by bits 2:0 /// (Log2(Number of bytes 
> +in cache line)) - 4 is used to represent /// the LineSize bits.
> +#define PPTT_ARM_CACHE_LINE_SIZE_MAX                  (1 << 11)
> +#define PPTT_ARM_CACHE_LINE_SIZE_MIN                  (1 << 4)
> +
> +#endif // if defined (MDE_CPU_ARM) || defined (MDE_CPU_AARCH64)
> +
> +#endif // PPTT_PARSER_H_
> --
> 'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'
>