Re: [PATCH v2 18/21] DynamicTablesPkg: AML code generation for a _LPI object

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

Hi Pierre,

Thank you for this patch.

Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

Regards,

Sami Mujawar

On 07/10/2021 04:32 PM, Pierre.Gondois@arm.com wrote:
> From: Pierre Gondois <Pierre.Gondois@arm.com>
>
> _LPI object provides a method to describe Low Power Idle
> states that define the local power states for each node
> in a hierarchical processor topology.
>
> Therefore, add AmlCreateLpiNode() to generate code for a
> _LPI object.
>
> AmlCreateLpiNode ("_LPI", 0, 1, ParentNode, &LpiNode) is
> equivalent of the following ASL code:
>    Name (_LPI, Package (
>               0,  // Revision
>               1,  // LevelId
>               0   // Count
>               ))
>
> Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
> ---
>   .../Include/Library/AmlLib/AmlLib.h           |  44 ++++++
>   .../Common/AmlLib/CodeGen/AmlCodeGen.c        | 133 ++++++++++++++++++
>   2 files changed, 177 insertions(+)
>
> diff --git a/DynamicTablesPkg/Include/Library/AmlLib/AmlLib.h b/DynamicTablesPkg/Include/Library/AmlLib/AmlLib.h
> index 7740aac24470..40c45073d303 100644
> --- a/DynamicTablesPkg/Include/Library/AmlLib/AmlLib.h
> +++ b/DynamicTablesPkg/Include/Library/AmlLib/AmlLib.h
> @@ -672,6 +672,50 @@ AmlCodeGenMethodRetNameString (
>     OUT       AML_OBJECT_NODE_HANDLE  * NewObjectNode        OPTIONAL
>     );
>
> +/** Create a _LPI name.
> +
> +  AmlCreateLpiNode ("_LPI", 0, 1, ParentNode, &LpiNode) is
> +  equivalent of the following ASL code:
> +    Name (_LPI, Package (
> +                  0,  // Revision
> +                  1,  // LevelId
> +                  0   // Count
> +                  ))
> +
> +  This function doesn't define any LPI state. As shown above, the count
> +  of _LPI state is set to 0.
> +  The AmlAddLpiState () function must be used to add LPI states.
> +
> +  Cf ACPI 6.3 specification, s8.4.4 "Lower Power Idle States".
> +
> +  @ingroup CodeGenApis
> +
> +  @param [in]  LpiNameString  The new LPI 's object name.
> +                              Must be a NULL-terminated ASL NameString
> +                              e.g.: "_LPI", "DEV0.PLPI", etc.
> +                              The input string is copied.
> +  @param [in]  Revision       Revision number of the _LPI states.
> +  @param [in]  LevelId        A platform defined number that identifies the
> +                              level of hierarchy of the processor node to
> +                              which the LPI states apply.
> +  @param [in]  ParentNode     If provided, set ParentNode as the parent
> +                              of the node created.
> +  @param [out] NewLpiNode     If success, contains the created node.
> +
> +  @retval EFI_SUCCESS             The function completed successfully.
> +  @retval EFI_INVALID_PARAMETER   Invalid parameter.
> +  @retval EFI_OUT_OF_RESOURCES    Failed to allocate memory.
> +**/
> +EFI_STATUS
> +EFIAPI
> +AmlCreateLpiNode (
> +  IN  CONST CHAR8                   * LpiNameString,
> +  IN        UINT16                    Revision,
> +  IN        UINT64                    LevelId,
> +  IN        AML_NODE_HANDLE           ParentNode,  OPTIONAL
> +  OUT       AML_OBJECT_NODE_HANDLE  * NewLpiNode   OPTIONAL
> +  );
> +
>   // DEPRECATED APIS
>   #ifndef DISABLE_NEW_DEPRECATED_INTERFACES
>
> diff --git a/DynamicTablesPkg/Library/Common/AmlLib/CodeGen/AmlCodeGen.c b/DynamicTablesPkg/Library/Common/AmlLib/CodeGen/AmlCodeGen.c
> index 67474094b975..2223e4bcfef9 100644
> --- a/DynamicTablesPkg/Library/Common/AmlLib/CodeGen/AmlCodeGen.c
> +++ b/DynamicTablesPkg/Library/Common/AmlLib/CodeGen/AmlCodeGen.c
> @@ -1442,3 +1442,136 @@ error_handler:
>     }
>     return Status;
>   }
> +
> +/** Create a _LPI name.
> +
> +  AmlCreateLpiNode ("_LPI", 0, 1, ParentNode, &LpiNode) is
> +  equivalent of the following ASL code:
> +    Name (_LPI, Package (
> +                  0,  // Revision
> +                  1,  // LevelId
> +                  0   // Count
> +                  ))
> +
> +  This function doesn't define any LPI state. As shown above, the count
> +  of _LPI state is set to 0.
> +  The AmlAddLpiState () function allows to add LPI states.
> +
> +  Cf ACPI 6.3 specification, s8.4.4 "Lower Power Idle States".
> +
> +  @param [in]  LpiNameString  The new LPI 's object name.
> +                              Must be a NULL-terminated ASL NameString
> +                              e.g.: "_LPI", "DEV0.PLPI", etc.
> +                              The input string is copied.
> +  @param [in]  Revision       Revision number of the _LPI states.
> +  @param [in]  LevelId        A platform defined number that identifies the
> +                              level of hierarchy of the processor node to
> +                              which the LPI states apply.
> +  @param [in]  ParentNode     If provided, set ParentNode as the parent
> +                              of the node created.
> +  @param [out] NewLpiNode     If success, contains the created node.
> +
> +  @retval EFI_SUCCESS             The function completed successfully.
> +  @retval EFI_INVALID_PARAMETER   Invalid parameter.
> +  @retval EFI_OUT_OF_RESOURCES    Failed to allocate memory.
> +**/
> +EFI_STATUS
> +EFIAPI
> +AmlCreateLpiNode (
> +  IN  CONST CHAR8                   * LpiNameString,
> +  IN        UINT16                    Revision,
> +  IN        UINT64                    LevelId,
> +  IN        AML_NODE_HANDLE           ParentNode,  OPTIONAL
> +  OUT       AML_OBJECT_NODE_HANDLE  * NewLpiNode   OPTIONAL
> +  )
> +{
> +  EFI_STATUS                Status;
> +  AML_OBJECT_NODE_HANDLE    PackageNode;
> +  AML_OBJECT_NODE_HANDLE    IntegerNode;
> +
> +  if ((LpiNameString == NULL)                           ||
> +      ((ParentNode == NULL) && (NewLpiNode == NULL))) {
> +    ASSERT (0);
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  IntegerNode = NULL;
> +
> +  Status = AmlCodeGenPackage (&PackageNode);
> +  if (EFI_ERROR (Status)) {
> +    ASSERT (0);
> +    return Status;
> +  }
> +
> +  // Create and attach Revision
> +  Status = AmlCodeGenInteger (Revision, &IntegerNode);
> +  if (EFI_ERROR (Status)) {
> +    ASSERT (0);
> +    IntegerNode = NULL;
> +    goto error_handler;
> +  }
> +
> +  Status = AmlVarListAddTail (
> +             (AML_NODE_HANDLE)PackageNode,
> +             (AML_NODE_HANDLE)IntegerNode
> +             );
> +  if (EFI_ERROR (Status)) {
> +    ASSERT (0);
> +    goto error_handler;
> +  }
> +
> +  IntegerNode = NULL;
> +
> +  // Create and attach LevelId
> +  Status = AmlCodeGenInteger (LevelId, &IntegerNode);
> +  if (EFI_ERROR (Status)) {
> +    ASSERT (0);
> +    IntegerNode = NULL;
> +    goto error_handler;
> +  }
> +
> +  Status = AmlVarListAddTail (
> +             (AML_NODE_HANDLE)PackageNode,
> +             (AML_NODE_HANDLE)IntegerNode
> +             );
> +  if (EFI_ERROR (Status)) {
> +    ASSERT (0);
> +    goto error_handler;
> +  }
> +
> +  IntegerNode = NULL;
> +
> +  // Create and attach Count. No LPI state is added, so 0.
> +  Status = AmlCodeGenInteger (0, &IntegerNode);
> +  if (EFI_ERROR (Status)) {
> +    ASSERT (0);
> +    IntegerNode = NULL;
> +    goto error_handler;
> +  }
> +
> +  Status = AmlVarListAddTail (
> +             (AML_NODE_HANDLE)PackageNode,
> +             (AML_NODE_HANDLE)IntegerNode
> +             );
> +  if (EFI_ERROR (Status)) {
> +    ASSERT (0);
> +    goto error_handler;
> +  }
> +
> +  IntegerNode = NULL;
> +
> +  Status = AmlCodeGenName (LpiNameString, PackageNode, ParentNode, NewLpiNode);
> +  if (EFI_ERROR (Status)) {
> +    ASSERT (0);
> +    goto error_handler;
> +  }
> +
> +  return Status;
> +
> +error_handler:
> +  AmlDeleteTree ((AML_NODE_HANDLE)PackageNode);
> +  if (IntegerNode != NULL) {
> +    AmlDeleteTree ((AML_NODE_HANDLE)IntegerNode);
> +  }
> +  return Status;
> +}

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