Re: [PATCH v4 2/3] DynamicTablesPkg: AML Code generation to add _CPC entries

["Jeff Brasen" <jbrasen@nvidia.com>]

Thanks will fix those in v5. Will see if Sami has any other comments before pushing these.


-Jeff


> -----Original Message-----
> From: Pierre Gondois <pierre.gondois@arm.com>
> Sent: Tuesday, September 20, 2022 8:54 AM
> To: Jeff Brasen <jbrasen@nvidia.com>; devel@edk2.groups.io
> Cc: ardb+tianocore@kernel.org; Alexei.Fedorov@arm.com; nd@arm.com;
> sami.mujawar@arm.com
> Subject: Re: [PATCH v4 2/3] DynamicTablesPkg: AML Code generation to add
> _CPC entries
> 
> External email: Use caution opening links or attachments
> 
> 
> Hello Jeff,
> Just 2 minors comments. Maybe Sami will have more.
> Otherwise, for the 3 patches:
> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
> 
> Regards,
> Pierre
> 
> On 9/20/22 00:01, Jeff Brasen wrote:
> > _CPC entries can describe CPU performance information.
> > The object is described in ACPI 6.4 s8.4.7.1.
> > "_CPC (Continuous Performance Control)".
> >
> > Add AmlCreateCpcNode() helper function to add _CPC entries to an
> > existing CPU object.
> >
> > Signed-off-by: Jeff Brasen <jbrasen@nvidia.com>
> > ---
> >   .../Include/Library/AmlLib/AmlLib.h           |  54 ++
> >   .../Common/AmlLib/CodeGen/AmlCodeGen.c        | 476
> ++++++++++++++++++
> >   2 files changed, 530 insertions(+)
> >
> > diff --git a/DynamicTablesPkg/Include/Library/AmlLib/AmlLib.h
> > b/DynamicTablesPkg/Include/Library/AmlLib/AmlLib.h
> > index 39968660f2..ebaccba811 100644
> > --- a/DynamicTablesPkg/Include/Library/AmlLib/AmlLib.h
> > +++ b/DynamicTablesPkg/Include/Library/AmlLib/AmlLib.h
> 
> [snip]
> 
> > +
> > +/** Adds an integer or register to the package
> > +
> > +  @ingroup CodeGenApis
> > +
> > +  @param [in]  Register     If provided, register that will be added to
> package
> > +  @param [in]  Integer      If Register is NULL, integer that will be added to
> the package
> > +  @param [in]  PackageNode  Package to add value to
> > +
> > +  @retval EFI_SUCCESS             The function completed successfully.
> > +  @retval EFI_INVALID_PARAMETER   Invalid parameter.
> > +  @retval EFI_OUT_OF_RESOURCES    Failed to allocate memory.
> > +**/
> > +STATIC
> > +EFI_STATUS
> > +EFIAPI
> > +AmlAddRegisterOrIntegerToPackage (
> > +  IN EFI_ACPI_6_4_GENERIC_ADDRESS_STRUCTURE  *Register OPTIONAL,
> > +  IN UINT32                                  Integer,
> > +  IN AML_OBJECT_NODE_HANDLE                  PackageNode
> > +  )
> > +{
> > +  EFI_STATUS              Status;
> > +  AML_OBJECT_NODE_HANDLE  IntegerNode;
> > +
> > +  IntegerNode = NULL;
> > +
> 
> I think that with IsNullGenericAddress(), the first
>   (Register != NULL)
> is not necessary.
> 
> > +  if ((Register != NULL) && !IsNullGenericAddress (Register)) {
> > +    Status = AmlAddRegisterToPackage (Register, PackageNode);  } else
> > + {
> > +    Status = AmlCodeGenInteger (Integer, &IntegerNode);
> > +    if (EFI_ERROR (Status)) {
> > +      ASSERT_EFI_ERROR (Status);
> > +      return Status;
> > +    }
> > +
> > +    Status = AmlVarListAddTail (
> > +               (AML_NODE_HANDLE)PackageNode,
> > +               (AML_NODE_HANDLE)IntegerNode
> > +               );
> > +  }
> > +
> > +  if (EFI_ERROR (Status)) {
> > +    ASSERT_EFI_ERROR (Status);
> > +    if (IntegerNode != NULL) {
> > +      AmlDeleteTree ((AML_NODE_HANDLE)IntegerNode);
> > +    }
> > +  }
> > +
> > +  return Status;
> > +}
> > +
> > +/** Create a _CPC node.
> > +
> > +  Creates and optionally adds the following node
> > +   Name(_CPC, Package()
> > +   {
> > +    NumEntries,                              // Integer
> > +    Revision,                                // Integer
> > +    HighestPerformance,                      // Integer or Buffer (Resource
> Descriptor)
> > +    NominalPerformance,                      // Integer or Buffer (Resource
> Descriptor)
> > +    LowestNonlinearPerformance,              // Integer or Buffer (Resource
> Descriptor)
> > +    LowestPerformance,                       // Integer or Buffer (Resource
> Descriptor)
> > +    GuaranteedPerformanceRegister,           // Buffer (Resource Descriptor)
> > +    DesiredPerformanceRegister ,             // Buffer (Resource Descriptor)
> > +    MinimumPerformanceRegister ,             // Buffer (Resource Descriptor)
> > +    MaximumPerformanceRegister ,             // Buffer (Resource Descriptor)
> > +    PerformanceReductionToleranceRegister,   // Buffer (Resource
> Descriptor)
> > +    TimeWindowRegister,                      // Buffer (Resource Descriptor)
> > +    CounterWraparoundTime,                   // Integer or Buffer (Resource
> Descriptor)
> > +    ReferencePerformanceCounterRegister,     // Buffer (Resource
> Descriptor)
> > +    DeliveredPerformanceCounterRegister,     // Buffer (Resource
> Descriptor)
> > +    PerformanceLimitedRegister,              // Buffer (Resource Descriptor)
> > +    CPPCEnableRegister                       // Buffer (Resource Descriptor)
> > +    AutonomousSelectionEnable,               // Integer or Buffer (Resource
> Descriptor)
> > +    AutonomousActivityWindowRegister,        // Buffer (Resource
> Descriptor)
> > +    EnergyPerformancePreferenceRegister,     // Buffer (Resource
> Descriptor)
> > +    ReferencePerformance                     // Integer or Buffer (Resource
> Descriptor)
> > +    LowestFrequency,                         // Integer or Buffer (Resource
> Descriptor)
> > +    NominalFrequency                         // Integer or Buffer (Resource
> Descriptor)
> > +  })
> > +
> > +  If resource buffer is NULL then integer will be used.
> > +
> > +  Cf. ACPI 6.4, s8.4.7.1 _CPC (Continuous Performance Control)
> > +
> > +  @ingroup CodeGenApis
> > +
> > +  @param [in]  CpcInfo               CpcInfo object
> > +  @param [in]  ParentNode            If provided, set ParentNode as the
> parent
> > +                                     of the node created.
> > +  @param [out] NewCpcNode            If success and provided, 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
> > +AmlCreateCpcNode (
> > +  IN  AML_CPC_INFO            *CpcInfo,
> > +  IN  AML_NODE_HANDLE         ParentNode   OPTIONAL,
> > +  OUT AML_OBJECT_NODE_HANDLE  *NewCpcNode   OPTIONAL
> > +  )
> > +{
> > +  EFI_STATUS              Status;
> > +  AML_OBJECT_NODE_HANDLE  CpcNode;
> > +  AML_OBJECT_NODE_HANDLE  CpcPackage;
> > +  UINT32                  NumberOfEntries;
> > +
> > +  if ((CpcInfo == NULL) ||
> > +      ((ParentNode == NULL) && (NewCpcNode == NULL)))  {
> > +    ASSERT (0);
> > +    return EFI_INVALID_PARAMETER;
> > +  }
> > +
> > +  // Revision 3 per ACPI 6.4 specification  if (CpcInfo->Revision ==
> > + 3) {
> > +    // NumEntries 23 per ACPI 6.4 specification
> > +    NumberOfEntries = 23;
> > +  } else {
> > +    ASSERT (0);
> > +    return EFI_INVALID_PARAMETER;
> > +  }
> > +
> 
> It seems CpcInfo is already checked earlier. It seems the checks below could
> be part of the other checks above (where ParentNode is checked).
> 
> > +  if ((CpcInfo == NULL) ||
> > +      (IsNullGenericAddress (&CpcInfo->HighestPerformanceBuffer) &&
> > +       (CpcInfo->HighestPerformanceInteger == 0)) ||
> > +      (IsNullGenericAddress (&CpcInfo->NominalPerformanceBuffer) &&
> > +       (CpcInfo->NominalPerformanceInteger == 0)) ||
> > +      (IsNullGenericAddress (&CpcInfo-
> >LowestNonlinearPerformanceBuffer) &&
> > +       (CpcInfo->LowestNonlinearPerformanceInteger == 0)) ||
> > +      (IsNullGenericAddress (&CpcInfo->LowestPerformanceBuffer) &&
> > +       (CpcInfo->LowestPerformanceInteger == 0)) ||
> > +      IsNullGenericAddress (&CpcInfo->DesiredPerformanceRegister) ||
> > +      IsNullGenericAddress (&CpcInfo-
> >ReferencePerformanceCounterRegister) ||
> > +      IsNullGenericAddress (&CpcInfo-
> >DeliveredPerformanceCounterRegister) ||
> > +      IsNullGenericAddress (&CpcInfo->PerformanceLimitedRegister))
> > +  {
> > +    ASSERT (0);
> > +    return EFI_INVALID_PARAMETER;
> > +  }
> > +
> > +  CpcPackage = NULL;
> > +
> > +  Status = AmlCodeGenNamePackage ("_CPC", NULL, &CpcNode);  if
> > + (EFI_ERROR (Status)) {
> > +    ASSERT_EFI_ERROR (Status);
> > +    return Status;
> > +  }
> > +
> 
> [snip]