Re: [PATCH v1 1/1] DynamicTablesPkg: Add support to specify FADT minor revision

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

Hi Pierre,

On 06/07/2022 04:03 pm, Pierre Gondois wrote:
> Hello Sami,
> The only configuration manager not using ACPI 6.4 tables is at:
> Platform/NXP/ConfigurationManagerPkg/ConfigurationManagerDxe/ConfigurationManager.c 
>
>
> I think the minor version of its FADT table needs to be updated along 
> with
> this patch. Otherwise:
>
Thank you for bringing this up.

As it stands the NXP platform would be using ACPI 6.4 which is the 
default case, and this patch will not change that. So, downgrading this 
to ACPI 6.2 may not be expected.

I have copied the NXP package maintainers for further inputs. If needed, 
I could submit a edk2-platforms patch as required.

Regards,

Sami Mujawar


> Reviewed-by: <pierre.gondois@arm.com>
>
> Regards,
> Pierre
>
> On 7/6/22 13:40, Sami Mujawar wrote:
>> The CM_STD_OBJ_ACPI_TABLE_INFO.AcpiTableRevision can be used to specify
>> the major revision number of the ACPI table that the generator must use.
>> Although most ACPI tables only have a major revision number, the FADT
>> table additionally has a minor revision number.
>>
>> The FADT generator currently defaults to setting the latest supported
>> ACPI revision for the FADT table i.e. ACPI 6.4. This means that the 
>> minor
>> revision for the FADT table is always set to 4 and there is no provision
>> for a user to specify the minor revision to be selected.
>>
>> Therefore, update CM_STD_OBJ_ACPI_TABLE_INFO to introduce a new field
>> MinorRevision which can be used to specify the minor revision for an
>> ACPI table. Also update the FADT generator to validate the supported
>> FADT revisions ans use the specified minor revision for the FADT table
>> if supported. If an unsupported minor revision is specified the FADT
>> generator defaults to the latest supported minor revision.
>>
>> Since the CM_STD_OBJ_ACPI_TABLE_INFO.MinorRevision field is added to
>> the end of the structure, it should not break existing platform code.
>>
>> Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
>> ---
>> The changes can be seen at:
>> https://github.com/samimujawar/edk2/tree/2221_support_fadt_minor_rev_v1
>>
>> DynamicTablesPkg/Include/StandardNameSpaceObjects.h | 10 ++++++-
>> DynamicTablesPkg/Library/Acpi/Arm/AcpiFadtLibArm/FadtGenerator.c | 29 
>> ++++++++++++++++++--
>>   2 files changed, 36 insertions(+), 3 deletions(-)
>>
>> diff --git a/DynamicTablesPkg/Include/StandardNameSpaceObjects.h 
>> b/DynamicTablesPkg/Include/StandardNameSpaceObjects.h
>> index 
>> 8d0c7da15a73e4910f9099c68f6e5cc2f06c0ecb..8ec3238225abe4fc16a7337c29ecd655590b408f 
>> 100644
>> --- a/DynamicTablesPkg/Include/StandardNameSpaceObjects.h
>> +++ b/DynamicTablesPkg/Include/StandardNameSpaceObjects.h
>> @@ -1,6 +1,6 @@
>>   /** @file
>>   -  Copyright (c) 2017 - 2019, ARM Limited. All rights reserved.
>> +  Copyright (c) 2017 - 2022, Arm Limited. All rights reserved.
>>       SPDX-License-Identifier: BSD-2-Clause-Patent
>>   @@ -105,6 +105,14 @@ typedef struct CmAStdObjAcpiTableInfo {
>>     /// Generators shall populate this information using the revision 
>> of the
>>     /// Configuration Manager 
>> (CM_STD_OBJ_CONFIGURATION_MANAGER_INFO.Revision).
>>     UINT32    OemRevision;
>> +
>> +  /// The minor revision of an ACPI table if required by the table.
>> +  /// Note: If this field is not populated (has value of Zero), then 
>> the
>> +  /// Generators shall populate this information based on the latest 
>> minor
>> +  /// revision of the table that is supported by the generator.
>> +  /// e.g. This field can be used to specify the minor revision to 
>> be set
>> +  /// for the FADT table.
>> +  UINT8     MinorRevision;
>>   } CM_STD_OBJ_ACPI_TABLE_INFO;
>>     /** A structure used to describe the SMBIOS table generators to 
>> be invoked.
>> diff --git 
>> a/DynamicTablesPkg/Library/Acpi/Arm/AcpiFadtLibArm/FadtGenerator.c 
>> b/DynamicTablesPkg/Library/Acpi/Arm/AcpiFadtLibArm/FadtGenerator.c
>> index 
>> 96295f539fb0505378e862edeef898be40257cdd..1d10ea55e2395c55291faa3c247e5c59e345650c 
>> 100644
>> --- a/DynamicTablesPkg/Library/Acpi/Arm/AcpiFadtLibArm/FadtGenerator.c
>> +++ b/DynamicTablesPkg/Library/Acpi/Arm/AcpiFadtLibArm/FadtGenerator.c
>> @@ -1,7 +1,7 @@
>>   /** @file
>>     FADT Table Generator
>>   -  Copyright (c) 2017 - 2021, ARM Limited. All rights reserved.
>> +  Copyright (c) 2017 - 2022, Arm Limited. All rights reserved.
>>     SPDX-License-Identifier: BSD-2-Clause-Patent
>>       @par Reference(s):
>> @@ -167,7 +167,7 @@ EFI_ACPI_6_4_FIXED_ACPI_DESCRIPTION_TABLE 
>> AcpiFadt = {
>>     // UINT16     ArmBootArch
>>     EFI_ACPI_6_4_ARM_PSCI_COMPLIANT,  // {Template}: ARM Boot 
>> Architecture Flags
>>     // UINT8      MinorRevision
>> -  EFI_ACPI_6_4_FIXED_ACPI_DESCRIPTION_TABLE_MINOR_REVISION,
>> +  EFI_ACPI_6_4_FIXED_ACPI_DESCRIPTION_TABLE_MINOR_REVISION, // 
>> {Template}
>>     // UINT64     XFirmwareCtrl
>>     0,
>>     // UINT64     XDsdt
>> @@ -546,6 +546,31 @@ BuildFadtTable (
>>       goto error_handler;
>>     }
>>   +  // Update the MinorRevision for the FADT table if it has been 
>> specified
>> +  // otherwise default to the latest FADT minor revision supported.
>> +  // Note:
>> +  // Bits 0-3 - The low order bits correspond to the minor version 
>> of the
>> +  //            specification version.
>> +  // Bits 4-7 - The high order bits correspond to the version of the 
>> ACPI
>> +  //            specification errata.
>> +  if (AcpiTableInfo->MinorRevision != 0) {
>> +    if (((AcpiTableInfo->MinorRevision & 0xF) >=
>> + EFI_ACPI_6_2_FIXED_ACPI_DESCRIPTION_TABLE_MINOR_REVISION) &&
>> +        ((AcpiTableInfo->MinorRevision & 0xF) <=
>> + EFI_ACPI_6_4_FIXED_ACPI_DESCRIPTION_TABLE_MINOR_REVISION))
>> +    {
>> +      AcpiFadt.MinorVersion = AcpiTableInfo->MinorRevision;
>> +    } else {
>> +      DEBUG ((
>> +        DEBUG_WARN,
>> +        "WARNING: FADT: Unsupported FADT Minor Revision 0x%x 
>> specified, " \
>> +        "defaulting to FADT Minor Revision 0x%x\n",
>> +        AcpiTableInfo->MinorRevision,
>> + EFI_ACPI_6_4_FIXED_ACPI_DESCRIPTION_TABLE_MINOR_REVISION
>> +        ));
>> +    }
>> +  }
>> +
>>     // Update PmProfile Info
>>     Status = FadtAddPmProfileInfo (CfgMgrProtocol);
>>     if (EFI_ERROR (Status)) {