Re: [PATCH 1/2] Mde Pkg: Support for MPAM ACPI Table

["Sami Mujawar" <sami.mujawar@arm.com>]

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Hi Swatisri,

Apologies for the delay in feedback.

There is a new version of "ACPI for Memory System Resource Partitioning 
and Monitoring 2.0, Platform Design Document" published on 2022/Sep/30 
at https://developer.arm.com/documentation/den0065/latest.

The version 2.0 of ACPI MPAM table has a few errata fixes and some new 
additions. Therefore, the version 1.0 of the ACPI MPAM table stands 
deprecated and must not be used.

I would therefore suggest that this patch is updated to reflect ACPI 
MPAM table version 2.0. I also have some feedback below that would still 
apply.

Regards,

Sami Mujawar

On 16/08/2022 09:18 pm, Name wrote:
> From: Swatisri Kantamsetti<swatisrik@nvidia.com>
>
> Added MPAM table header, MSC and Resource Node
> info structures
>
> Signed-off-by: Swatisri Kantamsetti<swatisrik@nvidia.com>
> ---
>   MdePkg/Include/IndustryStandard/Acpi64.h |  5 ++
>   MdePkg/Include/IndustryStandard/Mpam.h   | 69 ++++++++++++++++++++++++
>   2 files changed, 74 insertions(+)
>   create mode 100644 MdePkg/Include/IndustryStandard/Mpam.h
>
> diff --git a/MdePkg/Include/IndustryStandard/Acpi64.h b/MdePkg/Include/IndustryStandard/Acpi64.h
> index fe5ebfac2b..e54f631186 100644
> --- a/MdePkg/Include/IndustryStandard/Acpi64.h
> +++ b/MdePkg/Include/IndustryStandard/Acpi64.h
> @@ -2952,6 +2952,11 @@ typedef struct {
>   ///
>   #define EFI_ACPI_6_4_PROCESSOR_PROPERTIES_TOPOLOGY_TABLE_STRUCTURE_SIGNATURE  SIGNATURE_32('P', 'P', 'T', 'T')
>   
> +///
> +/// "MPAM" Memory System Resource Partitioning And Monitoring Table
> +///
> +#define EFI_ACPI_6_4_MEMORY_SYSTEM_RESOURCE_PARTITIONING_MONITORING_TABLE_STRUCTURE_SIGNATURE  SIGNATURE_32('M', 'P', 'A', 'M')
> +
>   ///
>   /// "PSDT" Persistent System Description Table
>   ///
> diff --git a/MdePkg/Include/IndustryStandard/Mpam.h b/MdePkg/Include/IndustryStandard/Mpam.h
> new file mode 100644
> index 0000000000..e0f75f0114
> --- /dev/null
> +++ b/MdePkg/Include/IndustryStandard/Mpam.h
> @@ -0,0 +1,69 @@
> +/** @file
> +  ACPI Memory System Resource Partitioning And Monitoring (MPAM)
> +  as specified in ARM spec DEN0065
> +
> +  Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved.
> +  Copyright (c) 2022, ARM Limited. All rights reserved.
> +  SPDX-License-Identifier: BSD-2-Clause-Patent

[SAMI] Please add a '@par Specification Reference:' section as shown in 
https://edk2-docs.gitbook.io/edk-ii-c-coding-standards-specification/5_source_files/53_include_files#5.3.7-include-files-shall-not-generate-code-or-define-data-variables.

e.g.

@par Specification Reference:

- [1] ACPI for Memory System Resource Partitioning and Monitoring 2.0, 
Platform Design Document

          (https://developer.arm.com/documentation/den0065/latest)

[/SAMI]

> +**/
> +
> +#ifndef _MPAM_H_
> +#define _MPAM_H_
[SAMI] I think the leading underscore should not be present, see 
https://edk2-docs.gitbook.io/edk-ii-c-coding-standards-specification/4_naming_conventions/43_identifiers#4.3.5.4-the-names-of-guard-macros-shall-end-with-an-underscore-character.
> +
> +#pragma pack(1)
> +
> +///
> +/// Memory System Resource Partitioning and Monitoring Table (MPAM)
> +///
> +typedef struct {
> +  EFI_ACPI_DESCRIPTION_HEADER    Header;
> +  UINT32                         NumNodes;
> +  UINT32                         NodeOffset;
> +  UINT32                         Reserved;
[SAMI] I do not see the NumNodes, NodeOffset and the Reserved filed in 
the specification. Can you check, please?
> +} EFI_ACPI_6_4_MEMORY_SYSTEM_RESOURCE_PARTITIONING_MONITORING_TABLE_HEADER;

[SAMI] I think the infix '_6_4_' is not going to work, as the ACPI MPAM 
table specification is not going to be in sync with the ACPI 
specification revision. So, this can be dropped.

Also, it may be better to add a @glossary section in the file header 
describing the MPAM acronym and abbreviate the structure names to 
EFI_ACPI_MPAM_TABLE_HEADER. The macro describing the table revision can 
also follow a similar approach.

[/SAMI]

> +
> +///
> +/// MPAM Revision (as defined in ACPI 6.4 spec.)
[SAMI] I believe this should be (a defined by the 'ACPI for Memory 
System Resource Partitioning and Monitoring, Platform Design Document'). 
Or simply refer it as '(as defined by [1])'.
> +///
> +#define EFI_ACPI_6_4_MEMORY_SYSTEM_RESOURCE_PARTITIONING_MONITORING_TABLE_REVISION  0x01
[SAMI] Please move this definition before the definition of 
EFI_ACPI_6_4_MEMORY_SYSTEM_RESOURCE_PARTITIONING_MONITORING_TABLE_HEADER. 
The ACPI MPAM 1.0 table revision was 0. But for ACPI MPAM table 2.0 the 
revision is 1, so there is no need to change.
> +
> +///
> +/// Memory System Controller Node Structure
> +///
> +
> +typedef struct {
> +  UINT16    Length;
> +  UINT16    Reserved;
[SAMI] ACPI MPAM 2.0 introduces splits the Reserved field to introduce 
'Interface type'.
> +  UINT32    Identifier;
> +  UINT64    BaseAddress;
> +  UINT32    MmioSize;
> +  UINT32    OverflowInterrupt;
> +  UINT32    OverflowInterruptFlags;
> +  UINT32    Reserved1;
> +  UINT32    OverflowInterruptAff;
> +  UINT32    ErrorInterrupt;
> +  UINT32    ErrorInterruptFlags;
> +  UINT32    Reserved2;
> +  UINT32    ErrorInterruptAff;
> +  UINT32    MaxNRdyUsec;
> +  UINT64    LinkedDeviceHwId;
> +  UINT32    LinkedDeviceInstanceHwId;
> +  UINT32    NumResourceNodes;
> +} EFI_ACPI_6_4_MPAM_MSC_NODE;
> +
> +///
> +/// Resource Node Structure
> +///
> +
> +typedef struct {
> +  UINT32    Identifier;
> +  UINT8     RisIndex;
> +  UINT16    Reserved1;
> +  UINT8     LocatorType;
> +  UINT64    Locator;

[SAMI] Would it be possible to define a Locator structure with the first 
field as the LocatorType followed by a union of Locators type specific 
structures?

> +  UINT32    NumFuncDep;
> +} EFI_ACPI_6_4_MPAM_RESOURCE_NODE;
> +

[SAMI] Do you have plans to add definitions for the other structures 
defined by the specifications, or the intention is to add them as required?

Also, if possible, it would be good to add an ACPI MPAM table parser to 
Acpiview.

[/SAMI]

> +#pragma pack()
> +
> +#endif

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