Re: [PATCH] DynamicTablesPkg: Allow multiple top level physical nodes

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

There are some cases (for example the _PSL list in thermal zones) where we need to have a reference to the node and we have been doing that via an Extern and a reference to the node path. I am push a patch where the effectively the PCD I added was fixed true but was unsure if that would have unexpected issues with other vendors platforms

-Jeff

> -----Original Message-----
> From: Pierre Gondois <pierre.gondois@arm.com>
> Sent: Thursday, February 2, 2023 10:49 AM
> To: Jeff Brasen <jbrasen@nvidia.com>; devel@edk2.groups.io
> Cc: Sami.Mujawar@arm.com; Alexei.Fedorov@arm.com;
> quic_llindhol@quicinc.com; ardb+tianocore@kernel.org
> Subject: Re: [PATCH] DynamicTablesPkg: Allow multiple top level physical
> nodes
> 
> External email: Use caution opening links or attachments
> 
> 
> Hello Jeff,
> I was assuming that no other module would rely on the AML path to access
> an AML node and that nodes should be retrieved through their
> characteristics instead, i.e. internal properties/Name/Uid.
> There are currently no public API allowing to do so, but there are internal
> APIs that could be relied on to create them.
> 
> I'm not sure what Sami is thinking,
> 
> Regards,
> Pierre
> 
> On 2/2/23 17:48, Jeff Brasen wrote:
> > Just to clarify you are suggesting that all CPU nodes generated via
> > this with have an outer processor container? I am fine with that but
> > was concerned with a change in behavior to other platforms in case
> > they are expecting the CPUs to just be under \SB.C00x instead of
> > \SB.C000.C00x
> >
> > -Jeff
> >
> >
> >> -----Original Message-----
> >> From: Pierre Gondois <pierre.gondois@arm.com>
> >> Sent: Thursday, February 2, 2023 5:03 AM
> >> To: Jeff Brasen <jbrasen@nvidia.com>; devel@edk2.groups.io
> >> Cc: Sami.Mujawar@arm.com; Alexei.Fedorov@arm.com;
> >> quic_llindhol@quicinc.com; ardb+tianocore@kernel.org
> >> Subject: Re: [PATCH] DynamicTablesPkg: Allow multiple top level
> >> physical nodes
> >>
> >> External email: Use caution opening links or attachments
> >>
> >>
> >> Hello Jeff,
> >> I think it's ok to make this the generic case and remove the Pcd to enable
> it.
> >> Cf ACPI 6.5, 5.2.30.1 Processor hierarchy node structure (Type 0):
> >>
> >> "Multiple trees may be described, covering for example multiple
> packages.
> >> For the root of a tree, the parent pointer should be 0."
> >> and
> >> "Each valid processor must belong to exactly one package. That is,
> >> the leaf must itself be a physical package or have an ancestor marked
> >> as a physical package."
> >>
> >> so this original comment is incorrect:
> >> """
> >> // It is assumed that there is one unique
> CM_ARM_PROC_HIERARCHY_INFO
> >> // structure with no ParentToken and the
> >> EFI_ACPI_6_3_PPTT_PACKAGE_PHYSICAL
> >> // flag set. All other CM_ARM_PROC_HIERARCHY_INFO are non-physical
> >> and // have a ParentToken.
> >> """
> >>
> >> On 2/1/23 17:42, Jeff Brasen wrote:
> >>> In SSDT CPU topology generator allow for multiple top level physical
> >>> nodes as would be seen with a multi-socket system. This will be auto
> >>> detected if there are more then one physical device and there is a
> >>> new PCD to enable forcing of a top level processor container to
> >>> allow for consistency for systems that can be either single or multi
> socket.
> >>>
> >>> Signed-off-by: Jeff Brasen <jbrasen@nvidia.com>
> >>> ---
> >>>    DynamicTablesPkg/DynamicTablesPkg.dec         |  3 +
> >>>    .../SsdtCpuTopologyGenerator.c                | 66 ++++++++++---------
> >>>    .../SsdtCpuTopologyLibArm.inf                 |  4 ++
> >>>    3 files changed, 41 insertions(+), 32 deletions(-)
> >>>
> >>> diff --git a/DynamicTablesPkg/DynamicTablesPkg.dec
> >>> b/DynamicTablesPkg/DynamicTablesPkg.dec
> >>> index adc2e67cbf..a061b70322 100644
> >>> --- a/DynamicTablesPkg/DynamicTablesPkg.dec
> >>> +++ b/DynamicTablesPkg/DynamicTablesPkg.dec
> >>> @@ -63,5 +63,8 @@
> >>>      # Use PCI segment numbers as UID
> >>>
> >>>
> >>
> gEdkiiDynamicTablesPkgTokenSpaceGuid.PcdPciUseSegmentAsUid|FALSE|B
> >> OOLE
> >>> AN|0x40000009
> >>>
> >>> +  # Force top level container for single socket devices
> >>> +
> >>
> gEdkiiDynamicTablesPkgTokenSpaceGuid.PcdForceTopLevelProcessorContai
> >>> + ner|FALSE|BOOLEAN|0x4000000A
> >>> +
> >>>    [Guids]
> >>>      gEdkiiDynamicTablesPkgTokenSpaceGuid = { 0xab226e66, 0x31d8,
> >>> 0x4613, { 0x87, 0x9d, 0xd2, 0xfa, 0xb6, 0x10, 0x26, 0x3c } } diff
> >>> --git
> >>>
> >>
> a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCp
> >> uT
> >>> opologyGenerator.c
> >>>
> >>
> b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCp
> >> uT
> >>> opologyGenerator.c
> >>> index c24da8ec71..58f86ff508 100644
> >>> ---
> >>>
> >>
> a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCp
> >> uT
> >>> opologyGenerator.c
> >>> +++
> >> b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/Ssdt
> >>> +++ CpuTopologyGenerator.c
> >>> @@ -22,6 +22,7 @@
> >>>    #include <Library/AcpiHelperLib.h>
> >>>    #include <Library/TableHelperLib.h>
> >>>    #include <Library/AmlLib/AmlLib.h>
> >>> +#include <Library/PcdLib.h>
> >>>    #include <Protocol/ConfigurationManagerProtocol.h>
> >>>
> >>>    #include "SsdtCpuTopologyGenerator.h"
> >>> @@ -814,7 +815,8 @@ CreateAmlProcessorContainer (
> >>>                                          Protocol Interface.
> >>>      @param [in] NodeToken               Token of the
> >> CM_ARM_PROC_HIERARCHY_INFO
> >>>                                          currently handled.
> >>> -                                      Cannot be CM_NULL_TOKEN.
> >>> +                                      CM_NULL_TOKEN if top level container
> >>> +                                      should be created.
> >>>      @param [in] ParentNode              Parent node to attach the created
> >>>                                          node to.
> >>>      @param [in,out] ProcContainerIndex  Pointer to the current
> >>> processor container @@ -841,12 +843,12 @@
> CreateAmlCpuTopologyTree
> >> (
> >>>      AML_OBJECT_NODE_HANDLE  ProcContainerNode;
> >>>      UINT32                  Uid;
> >>>      UINT16                  Name;
> >>> +  UINT32                  NodeFlags;
> >>>
> >>>      ASSERT (Generator != NULL);
> >>>      ASSERT (Generator->ProcNodeList != NULL);
> >>>      ASSERT (Generator->ProcNodeCount != 0);
> >>>      ASSERT (CfgMgrProtocol != NULL);
> >>> -  ASSERT (NodeToken != CM_NULL_TOKEN);
> >>>      ASSERT (ParentNode != NULL);
> >>>      ASSERT (ProcContainerIndex != NULL);
> >>>
> >>> @@ -893,8 +895,14 @@ CreateAmlCpuTopologyTree (
> >>>          } else {
> >>>            // If this is not a Cpu, then this is a processor container.
> >>>
> >>> +        NodeFlags = Generator->ProcNodeList[Index].Flags;
> >>> +        // Allow physical property for top level nodes
> >>> +        if (NodeToken == CM_NULL_TOKEN) {
> >>> +          NodeFlags &= ~EFI_ACPI_6_3_PPTT_PACKAGE_PHYSICAL;
> >>> +        }
> >>> +
> >>
> >> Even though it was never encountered so far, it should also be
> >> possible to have a physical package consisting of only one CPU. So I
> >> guess it would be better to create a function to check the flags,
> >> whether the ProcNode is a CPU or a cluster.
> >>
> >> I attached a Wip patch base on your work where such function is created.
> >> Feel free to take it/modify it at your will.
> >>
> >>>            // Acpi processor Id for clusters is not handled.
> >>> -        if ((Generator->ProcNodeList[Index].Flags &
> >> PPTT_PROCESSOR_MASK) !=
> >>> +        if ((NodeFlags & PPTT_PROCESSOR_MASK) !=
> >>>                PPTT_CLUSTER_PROCESSOR_MASK)
> >>>            {
> >>>              DEBUG ((
> >>> @@ -973,10 +981,10 @@ CreateTopologyFromProcHierarchy (
> >>>      IN        AML_OBJECT_NODE_HANDLE                        ScopeNode
> >>>      )
> >>>    {
> >>> -  EFI_STATUS  Status;
> >>> -  UINT32      Index;
> >>> -  UINT32      TopLevelProcNodeIndex;
> >>> -  UINT32      ProcContainerIndex;
> >>> +  EFI_STATUS       Status;
> >>> +  UINT32           Index;
> >>> +  CM_OBJECT_TOKEN  TopLevelToken;
> >>> +  UINT32           ProcContainerIndex;
> >>>
> >>>      ASSERT (Generator != NULL);
> >>>      ASSERT (Generator->ProcNodeCount != 0); @@ -984,8 +992,8 @@
> >>> CreateTopologyFromProcHierarchy (
> >>>      ASSERT (CfgMgrProtocol != NULL);
> >>>      ASSERT (ScopeNode != NULL);
> >>>
> >>> -  TopLevelProcNodeIndex = MAX_UINT32;
> >>> -  ProcContainerIndex    = 0;
> >>> +  TopLevelToken      = CM_NULL_TOKEN;
> >>> +  ProcContainerIndex = 0;
> >>>
> >>>      Status = TokenTableInitialize (Generator, Generator-
> >ProcNodeCount);
> >>>      if (EFI_ERROR (Status)) {
> >>> @@ -993,33 +1001,27 @@ CreateTopologyFromProcHierarchy (
> >>>        return Status;
> >>>      }
> >>>
> >>> -  // It is assumed that there is one unique
> >>> CM_ARM_PROC_HIERARCHY_INFO
> >>> -  // structure with no ParentToken and the
> >>> EFI_ACPI_6_3_PPTT_PACKAGE_PHYSICAL
> >>> -  // flag set. All other CM_ARM_PROC_HIERARCHY_INFO are
> >>> non-physical and
> >>> -  // have a ParentToken.
> >>> -  for (Index = 0; Index < Generator->ProcNodeCount; Index++) {
> >>> -    if ((Generator->ProcNodeList[Index].ParentToken ==
> >> CM_NULL_TOKEN) &&
> >>> -        (Generator->ProcNodeList[Index].Flags &
> >>> -         EFI_ACPI_6_3_PPTT_PACKAGE_PHYSICAL))
> >>> -    {
> >>> -      if (TopLevelProcNodeIndex != MAX_UINT32) {
> >>> -        DEBUG ((
> >>> -          DEBUG_ERROR,
> >>> -          "ERROR: SSDT-CPU-TOPOLOGY: Top level
> >> CM_ARM_PROC_HIERARCHY_INFO "
> >>> -          "must be unique\n"
> >>> -          ));
> >>> -        ASSERT (0);
> >>> -        goto exit_handler;
> >>> -      }
> >>> +  if (!PcdGetBool (PcdForceTopLevelProcessorContainer)) {
> >>> +    for (Index = 0; Index < Generator->ProcNodeCount; Index++) {
> >>> +      if ((Generator->ProcNodeList[Index].ParentToken ==
> >> CM_NULL_TOKEN) &&
> >>> +          (Generator->ProcNodeList[Index].Flags &
> >>> +           EFI_ACPI_6_3_PPTT_PACKAGE_PHYSICAL))
> >>> +      {
> >>> +        // Multi-socket detected, using top level containers
> >>> +        if (TopLevelToken != CM_NULL_TOKEN) {
> >>> +          TopLevelToken = CM_NULL_TOKEN;
> >>> +          break;
> >>> +        }
> >>>
> >>> -      TopLevelProcNodeIndex = Index;
> >>> -    }
> >>> -  } // for
> >>> +        TopLevelToken = Generator->ProcNodeList[Index].Token;
> >>> +      }
> >>> +    } // for
> >>> +  }
> >>>
> >>>      Status = CreateAmlCpuTopologyTree (
> >>>                 Generator,
> >>>                 CfgMgrProtocol,
> >>> -             Generator->ProcNodeList[TopLevelProcNodeIndex].Token,
> >>> +             TopLevelToken,
> >>>                 ScopeNode,
> >>>                 &ProcContainerIndex
> >>>                 );
> >>> @@ -1106,7 +1108,7 @@ CreateTopologyFromGicC (
> >>>            break;
> >>>          }
> >>>        }
> >>> -  } // for
> >>> +  }   // for
> >>
> >> Is it possible to remove this change ?
> >>
> >>>
> >>>      return Status;
> >>>    }
> >>> diff --git
> >>>
> >>
> a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCp
> >> uT
> >>> opologyLibArm.inf
> >>>
> >>
> b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCp
> >> uT
> >>> opologyLibArm.inf
> >>> index 3e2d154749..00adfe986f 100644
> >>> ---
> >>>
> >>
> a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCp
> >> uT
> >>> opologyLibArm.inf
> >>> +++
> >> b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/Ssdt
> >>> +++ CpuTopologyLibArm.inf
> >>> @@ -31,3 +31,7 @@
> >>>      AcpiHelperLib
> >>>      AmlLib
> >>>      BaseLib
> >>> +  PcdLib
> >>> +
> >>> +[Pcd]
> >>> +
> >>>
> >>
> +gEdkiiDynamicTablesPkgTokenSpaceGuid.PcdForceTopLevelProcessorConta
> >> in
> >>> +er