Re: [PATCH 1/2] DynamicTablesPkg: IORT generator updates for Rev E.e spec

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

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Hi Swatisri,

Thank you for this patch,

I have some suggestions marked inline as [SAMI].

Regards,

Sami Mujawar

On 25/01/2023 06:40 pm, Name wrote:
> From: Swatisri Kantamsetti<swatisrik@nvidia.com>
>
> The IO Remapping Table, Platform Design Document, Revision E.e,
> Sept 2022 (https://developer.arm.com/documentation/den0049/ee)
> added flags in SMMUv3 node for validity of ID mappings for MSIs
> related to control interrupts.
> It makes one small addition to SMMUv3 nodes to
> describe MSI support independently of wired GSIV support
>
> Therefore, update the IORT generator to:
> - increment IORT table revision to 6
> - increment SMMUV3 node revision to 5
> - for SMMUV3 node revision >=5 check the DeviceID mapping index
>    valid flag to populate DeviceIdMappingIndex field
> - preserve backward compatibility.
>
> Signed-off-by: Swatisri Kantamsetti<swatisrik@nvidia.com>
> ---
>   .../Acpi/Arm/AcpiIortLibArm/IortGenerator.c   | 36 ++++++++++++++-----
>   1 file changed, 28 insertions(+), 8 deletions(-)
>
> diff --git a/DynamicTablesPkg/Library/Acpi/Arm/AcpiIortLibArm/IortGenerator.c b/DynamicTablesPkg/Library/Acpi/Arm/AcpiIortLibArm/IortGenerator.c
> index f28973c1a8..235a475629 100644
> --- a/DynamicTablesPkg/Library/Acpi/Arm/AcpiIortLibArm/IortGenerator.c
> +++ b/DynamicTablesPkg/Library/Acpi/Arm/AcpiIortLibArm/IortGenerator.c
[SAMI] Can you update the file header with the IORT Spec revision, please?
> @@ -1554,9 +1554,14 @@ AddSmmuV3Nodes (
>       {
>         SmmuV3Node->Node.Revision   = 2;
>         SmmuV3Node->Node.Identifier = EFI_ACPI_RESERVED_DWORD;
> -    } else {
> +    } else if (AcpiTableInfo->AcpiTableRevision <
> +               EFI_ACPI_IO_REMAPPING_TABLE_REVISION_06)
> +    {
>         SmmuV3Node->Node.Revision   = 4;
>         SmmuV3Node->Node.Identifier = NodeList->Identifier;
> +    } else {
> +      SmmuV3Node->Node.Revision   = 5;
> +      SmmuV3Node->Node.Identifier = NodeList->Identifier;
>       }
>   
>       // SMMUv3 specific data
> @@ -1577,12 +1582,27 @@ AddSmmuV3Nodes (
>         SmmuV3Node->ProximityDomain = 0;
>       }

> <SNIP>
> -    if ((SmmuV3Node->Event != 0) && (SmmuV3Node->Pri != 0) &&
> -        (SmmuV3Node->Gerr != 0) && (SmmuV3Node->Sync != 0))
> -    {
> -      // If all the SMMU control interrupts are GSIV based,
> -      // the DeviceID mapping index field is ignored.
> -      SmmuV3Node->DeviceIdMappingIndex = 0;
> +    /* DeviceID mapping valid flag was introduced in IORT rev E.e
> +     * for SMMUV3 nodes rev. > 5.
> +     * For older revisions, if all the SMMU control interrupts are GSIV
> +     * based, DeviceID mapping index field is ignored.
> +     * If the DeviceID mapping index valid flag is set to 0,
> +     * DeviceID mapping index field must be ignored.
> +     * Where the SMMU uses message signaled interrupts for
> +     * its control interrupts, DeviceId Mapping Index contains an
> +     * index into the array of ID mapping.
> +     */
> +
> +    if ((SmmuV3Node->Node.Revision < 5) || (!(SmmuV3Node->Flags & EFI_ACPI_IORT_SMMUv3_FLAG_DEVICEID_VALID))) {
> +      if ((SmmuV3Node->Event != 0) && (SmmuV3Node->Pri != 0) &&
> +          (SmmuV3Node->Gerr != 0) && (SmmuV3Node->Sync != 0))
> +      {
> +        // If all the SMMU control interrupts are GSIV based,
> +        // the DeviceID mapping index field is ignored.
> +        SmmuV3Node->DeviceIdMappingIndex = 0;
> +      } else {
> +        SmmuV3Node->DeviceIdMappingIndex = NodeList->DeviceIdMappingIndex;
> +      }
>       } else {
>         SmmuV3Node->DeviceIdMappingIndex = NodeList->DeviceIdMappingIndex;
>       }

</SNIP>

[SAMI] I think the above code should be changed to the following:

     /* For older SMMUV3 nodes rev. < 5.
        If all the SMMU control interrupts are GSIV based,
        the DeviceID mapping index field is ignored.
        DeviceID mapping valid flag was introduced in IORT rev E.e
        for SMMUV3 nodes rev. > 5.
        If the DeviceID mapping index valid flag is set to 0,
        DeviceID mapping index field must be ignored.
        Where the SMMU uses message signaled interrupts for
        its control interrupts, DeviceId Mapping Index contains an
        index into the array of ID mapping.
      */
     if (((SmmuV3Node->Node.Revision < 5) &&
          (SmmuV3Node->Event != 0)        &&
          (SmmuV3Node->Pri != 0)          &&
          (SmmuV3Node->Gerr != 0)         &&
          (SmmuV3Node->Sync != 0)
         ) ||
         ((SmmuV3Node->Node.Revision >= 5) &&
          ((SmmuV3Node->Flags & EFI_ACPI_IORT_SMMUv3_FLAG_DEVICEID_VALID) == 0))
        ) {
       SmmuV3Node->DeviceIdMappingIndex = 0;
     } else {
       SmmuV3Node->DeviceIdMappingIndex = NodeList->DeviceIdMappingIndex;
     }

Can you check, please?

[/SAMI]

> @@ -2819,7 +2839,7 @@ ACPI_IORT_GENERATOR  IortGenerator = {
>       // ACPI Table Signature
>       EFI_ACPI_6_4_IO_REMAPPING_TABLE_SIGNATURE,
>       // ACPI Table Revision supported by this Generator
> -    EFI_ACPI_IO_REMAPPING_TABLE_REVISION_05,
> +    EFI_ACPI_IO_REMAPPING_TABLE_REVISION_06,
>       // Minimum supported ACPI Table Revision
>       EFI_ACPI_IO_REMAPPING_TABLE_REVISION_00,
>       // Creator ID

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