DynamicTablesPkg/SsdtCpuTopology: Allow multi-packages topologies

The topology of a platform is represented in ACPI using the PPTT
table. It is possible to append information to CPUs/processor
containers using their associated AML nodes in a SSDT
table.
A platform might have multiple 'physical packages' (or top-level
nodes) in their PPTT topology representation. It can be assumed
from [1] that a 'physical packages' is always a 'top-level node',
and conversely.

The SSDT topology generator doesn't support having multiple top-level
nodes. The top-level node is also not generated in the SSDT topology
representation.
Add support to generate multiple top-level nodes in the SSDT topology
generator and generate an AML node for this top-level node. This will
allow to have matching PPTT and SSDT topology representations. Prior
to this patch, this top-level AML node was not generated.

Also factorize the flag checking in CheckProcNode() and add more
checks.

This patch takes inspiration from the discussion at:
- v1: https://edk2.groups.io/g/devel/message/99410
- v2: https://edk2.groups.io/g/devel/message/99615

[1]
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.""
- "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."

Suggested-by: Jeff Brasen <jbrasen@nvidia.com>
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Jeff Brasen <jbrasen@nvidia.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

2 files changed, 84 insertions, 51 deletions

diff --git a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCpuTopologyGenerator.c b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCpuTopologyGenerator.c
index c24da8ec71..6fb131b664 100644
--- a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCpuTopologyGenerator.c
+++ b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCpuTopologyGenerator.c
@@ -805,6 +805,57 @@ CreateAmlProcessorContainer (
   return Status;

 }

 

+/** Check flags and topology of a ProcNode.

+

+  @param [in]  NodeFlags        Flags of the ProcNode to check.

+  @param [in]  IsLeaf           The ProcNode is a leaf.

+  @param [in]  NodeToken        NodeToken of the ProcNode.

+  @param [in]  ParentNodeToken  Parent NodeToken of the ProcNode.

+

+  @retval EFI_SUCCESS             Success.

+  @retval EFI_INVALID_PARAMETER   Invalid parameter.

+**/

+STATIC

+EFI_STATUS

+EFIAPI

+CheckProcNode (

+  UINT32           NodeFlags,

+  BOOLEAN          IsLeaf,

+  CM_OBJECT_TOKEN  NodeToken,

+  CM_OBJECT_TOKEN  ParentNodeToken

+  )

+{

+  BOOLEAN  InvalidFlags;

+  BOOLEAN  HasPhysicalPackageBit;

+  BOOLEAN  IsTopLevelNode;

+

+  HasPhysicalPackageBit = (NodeFlags & EFI_ACPI_6_3_PPTT_PACKAGE_PHYSICAL) ==

+                          EFI_ACPI_6_3_PPTT_PACKAGE_PHYSICAL;

+  IsTopLevelNode = (ParentNodeToken == CM_NULL_TOKEN);

+

+  // A top-level node is a Physical Package and conversely.

+  InvalidFlags = HasPhysicalPackageBit ^ IsTopLevelNode;

+

+  // Check Leaf specific flags.

+  if (IsLeaf) {

+    InvalidFlags |= ((NodeFlags & PPTT_LEAF_MASK) != PPTT_LEAF_MASK);

+  } else {

+    InvalidFlags |= ((NodeFlags & PPTT_LEAF_MASK) != 0);

+  }

+

+  if (InvalidFlags) {

+    DEBUG ((

+      DEBUG_ERROR,

+      "ERROR: SSDT-CPU-TOPOLOGY: Invalid flags for ProcNode: 0x%p.\n",

+      (VOID *)NodeToken

+      ));

+    ASSERT (0);

+    return EFI_INVALID_PARAMETER;

+  }

+

+  return EFI_SUCCESS;

+}

+

 /** Create an AML representation of the Cpu topology.

 

   A processor container is by extension any non-leave device in the cpu topology.

@@ -814,7 +865,6 @@ CreateAmlProcessorContainer (
                                       Protocol Interface.

   @param [in] NodeToken               Token of the CM_ARM_PROC_HIERARCHY_INFO

                                       currently handled.

-                                      Cannot be CM_NULL_TOKEN.

   @param [in] ParentNode              Parent node to attach the created

                                       node to.

   @param [in,out] ProcContainerIndex  Pointer to the current processor container

@@ -838,6 +888,7 @@ CreateAmlCpuTopologyTree (
   EFI_STATUS              Status;

   UINT32                  Index;

   UINT32                  CpuIndex;

+  UINT32                  ProcContainerName;

   AML_OBJECT_NODE_HANDLE  ProcContainerNode;

   UINT32                  Uid;

   UINT16                  Name;

@@ -846,11 +897,11 @@ CreateAmlCpuTopologyTree (
   ASSERT (Generator->ProcNodeList != NULL);

   ASSERT (Generator->ProcNodeCount != 0);

   ASSERT (CfgMgrProtocol != NULL);

-  ASSERT (NodeToken != CM_NULL_TOKEN);

   ASSERT (ParentNode != NULL);

   ASSERT (ProcContainerIndex != NULL);

 

-  CpuIndex = 0;

+  CpuIndex          = 0;

+  ProcContainerName = 0;

 

   for (Index = 0; Index < Generator->ProcNodeCount; Index++) {

     // Find the children of the CM_ARM_PROC_HIERARCHY_INFO

@@ -859,16 +910,15 @@ CreateAmlCpuTopologyTree (
       // Only Cpus (leaf nodes in this tree) have a GicCToken.

       // Create a Cpu node.

       if (Generator->ProcNodeList[Index].GicCToken != CM_NULL_TOKEN) {

-        if ((Generator->ProcNodeList[Index].Flags & PPTT_PROCESSOR_MASK) !=

-            PPTT_CPU_PROCESSOR_MASK)

-        {

-          DEBUG ((

-            DEBUG_ERROR,

-            "ERROR: SSDT-CPU-TOPOLOGY: Invalid flags for cpu: 0x%x.\n",

-            Generator->ProcNodeList[Index].Flags

-            ));

+        Status = CheckProcNode (

+                   Generator->ProcNodeList[Index].Flags,

+                   TRUE,

+                   Generator->ProcNodeList[Index].Token,

+                   NodeToken

+                   );

+        if (EFI_ERROR (Status)) {

           ASSERT (0);

-          return EFI_INVALID_PARAMETER;

+          return Status;

         }

 

         if (Generator->ProcNodeList[Index].OverrideNameUidEnabled) {

@@ -893,24 +943,22 @@ CreateAmlCpuTopologyTree (
       } else {

         // If this is not a Cpu, then this is a processor container.

 

-        // Acpi processor Id for clusters is not handled.

-        if ((Generator->ProcNodeList[Index].Flags & PPTT_PROCESSOR_MASK) !=

-            PPTT_CLUSTER_PROCESSOR_MASK)

-        {

-          DEBUG ((

-            DEBUG_ERROR,

-            "ERROR: SSDT-CPU-TOPOLOGY: Invalid flags for cluster: 0x%x.\n",

-            Generator->ProcNodeList[Index].Flags

-            ));

+        Status = CheckProcNode (

+                   Generator->ProcNodeList[Index].Flags,

+                   FALSE,

+                   Generator->ProcNodeList[Index].Token,

+                   NodeToken

+                   );

+        if (EFI_ERROR (Status)) {

           ASSERT (0);

-          return EFI_INVALID_PARAMETER;

+          return Status;

         }

 

         if (Generator->ProcNodeList[Index].OverrideNameUidEnabled) {

           Name = Generator->ProcNodeList[Index].OverrideName;

           Uid  = Generator->ProcNodeList[Index].OverrideUid;

         } else {

-          Name = *ProcContainerIndex;

+          Name = ProcContainerName;

           Uid  = *ProcContainerIndex;

         }

 

@@ -933,6 +981,13 @@ CreateAmlCpuTopologyTree (
         (*ProcContainerIndex)++;

         CpuIndex = 0;

 

+        // And reset the cluster name whenever there is a package.

+        if (NodeToken == CM_NULL_TOKEN) {

+          ProcContainerName = 0;

+        } else {

+          ProcContainerName++;

+        }

+

         // Recursively continue creating an AML tree.

         Status = CreateAmlCpuTopologyTree (

                    Generator,

@@ -974,8 +1029,6 @@ CreateTopologyFromProcHierarchy (
   )

 {

   EFI_STATUS  Status;

-  UINT32      Index;

-  UINT32      TopLevelProcNodeIndex;

   UINT32      ProcContainerIndex;

 

   ASSERT (Generator != NULL);

@@ -984,8 +1037,7 @@ CreateTopologyFromProcHierarchy (
   ASSERT (CfgMgrProtocol != NULL);

   ASSERT (ScopeNode != NULL);

 

-  TopLevelProcNodeIndex = MAX_UINT32;

-  ProcContainerIndex    = 0;

+  ProcContainerIndex = 0;

 

   Status = TokenTableInitialize (Generator, Generator->ProcNodeCount);

   if (EFI_ERROR (Status)) {

@@ -993,33 +1045,10 @@ 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;

-      }

-

-      TopLevelProcNodeIndex = Index;

-    }

-  } // for

-

   Status = CreateAmlCpuTopologyTree (

              Generator,

              CfgMgrProtocol,

-             Generator->ProcNodeList[TopLevelProcNodeIndex].Token,

+             CM_NULL_TOKEN,

              ScopeNode,

              &ProcContainerIndex

              );

diff --git a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCpuTopologyGenerator.h b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCpuTopologyGenerator.h
index f174d9c2e2..48e4455490 100644
--- a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCpuTopologyGenerator.h
+++ b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCpuTopologyGenerator.h
@@ -34,6 +34,10 @@
           (EFI_ACPI_6_3_PPTT_PROCESSOR_ID_INVALID << 1) |                     \

           (EFI_ACPI_6_3_PPTT_NODE_IS_NOT_LEAF << 3))

 

+// Leaf nodes specific mask.

+#define PPTT_LEAF_MASK  ((EFI_ACPI_6_3_PPTT_PROCESSOR_ID_VALID << 1) |        \

+                         (EFI_ACPI_6_3_PPTT_NODE_IS_LEAF << 3))

+

 /** LPI states are stored in the ASL namespace at '\_SB_.Lxxx',

     with xxx being the node index of the LPI state.

 */