Re: [edk2-devel] [PATCH v4 3/3] Platform/ARM: Juno: Generate _CPC objects for JunoR2

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

Hi Pierre,

Thank you for this patch.
Please find my feedback inline marked [SAMI].

Regards,

Sami Mujawar

On 12/12/2023, 09:31, "Pierre.Gondois@arm.com <mailto:Pierre.Gondois@arm.com>" <Pierre.Gondois@arm.com <mailto:Pierre.Gondois@arm.com>> wrote:


From: Pierre Gondois <pierre.gondois@arm.com <mailto:pierre.gondois@arm.com>>


The SsdtCpuTopologyGenerator can generate _CPC objects.
This is done by querying the SCP for the relevant performance
state information through SCMI. CM_ARM_CPC_INFO are then populated
and used to generate _CPC objects in the Ssdt Cpu topology.


Use the DynamicTablesScmiInfoLib and add the handling to generate
_CPC information.


Note that using _CPC is only possible if SCP is correctly tuned
to advertise performance levels on an abstract and unified scale.
A basic check is done to prevent the _CPC generation otherwise.


Signed-off-by: Pierre Gondois <pierre.gondois@arm.com <mailto:pierre.gondois@arm.com>>
---
.../ConfigurationManager.c | 233 +++++++++++++++++-
.../ConfigurationManager.h | 3 +
.../ConfigurationManagerDxe.inf | 1 +
3 files changed, 234 insertions(+), 3 deletions(-)


diff --git a/Platform/ARM/JunoPkg/ConfigurationManager/ConfigurationManagerDxe/ConfigurationManager.c b/Platform/ARM/JunoPkg/ConfigurationManager/ConfigurationManagerDxe/ConfigurationManager.c
index 15292f810a28..ba5727f65619 100644
--- a/Platform/ARM/JunoPkg/ConfigurationManager/ConfigurationManagerDxe/ConfigurationManager.c
+++ b/Platform/ARM/JunoPkg/ConfigurationManager/ConfigurationManagerDxe/ConfigurationManager.c
@@ -14,6 +14,7 @@
#include <IndustryStandard/MemoryMappedConfigurationSpaceAccessTable.h>
#include <IndustryStandard/SerialPortConsoleRedirectionTable.h>
#include <Library/ArmLib.h>
+#include <Library/DynamicTablesScmiInfoLib.h>
#include <Library/DebugLib.h>
#include <Library/IoLib.h>
#include <Library/PcdLib.h>
@@ -756,6 +757,8 @@ EDKII_PLATFORM_REPOSITORY_INFO ArmJunoPlatformRepositoryInfo = {
4,
},
},
+ { // CPC info, dynamically populated.
+ },
[SAMI] I think we should remove the above 2 lines. 
Please see my feedback for patch 2/3.
Also, if new fields are added then they should be before the CPC info objects. That way we can skip the initialisation of the CPC info in here.
[/SAMI]
};


/** A helper function for returning the Configuration Manager Objects.
@@ -1212,6 +1215,55 @@ GetPsdInfo (
return EFI_SUCCESS;
}


+/** Return Cpc Info.
+
+ @param [in] This Pointer to the Configuration Manager Protocol.
+ @param [in] CmObjectId The Object ID of the CM object requested
+ @param [in] SearchToken A unique token for identifying the requested
+ CM_ARM_PCI_INTERRUPT_MAP_INFO object.
+ @param [in, out] CmObject Pointer to the Configuration Manager Object
+ descriptor describing the requested Object.
+
+ @retval EFI_SUCCESS Success.
+ @retval EFI_INVALID_PARAMETER A parameter is invalid.
+ @retval EFI_NOT_FOUND The required object information is not found.
+**/
+EFI_STATUS
+EFIAPI
+GetCpcInfo (
+ IN CONST EDKII_CONFIGURATION_MANAGER_PROTOCOL * CONST This,
+ IN CONST CM_OBJECT_ID CmObjectId,
+ IN CONST CM_OBJECT_TOKEN SearchToken,
+ IN OUT CM_OBJ_DESCRIPTOR * CONST CmObject
+ )
+{
+ EDKII_PLATFORM_REPOSITORY_INFO * PlatformRepo;
+ UINT32 TotalObjCount;
+ UINT32 ObjIndex;
+
+ if ((This == NULL) || (CmObject == NULL)) {
+ ASSERT (This != NULL);
+ ASSERT (CmObject != NULL);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ PlatformRepo = This->PlatRepoInfo;
+
+ TotalObjCount = ARRAY_SIZE (PlatformRepo->CpcInfo);
+
+ for (ObjIndex = 0; ObjIndex < TotalObjCount; ObjIndex++) {
+ if (SearchToken == (CM_OBJECT_TOKEN)&PlatformRepo->CpcInfo[ObjIndex]) {
+ CmObject->ObjectId = CmObjectId;
+ CmObject->Size = sizeof (PlatformRepo->CpcInfo[ObjIndex]);
+ CmObject->Data = (VOID*)&PlatformRepo->CpcInfo[ObjIndex];
+ CmObject->Count = 1;
+ return EFI_SUCCESS;
+ }
+ }
+
+ return EFI_SUCCESS;
+}
+
/** Return a list of Configuration Manager object references pointed to by the
given input token.


@@ -1633,6 +1685,19 @@ GetArmNameSpaceObject (
);
break;


+ case EArmObjCpcInfo:
+ Status = HandleCmObjectRefByToken (
+ This,
+ CmObjectId,
+ PlatformRepo->CpcInfo,
+ sizeof (PlatformRepo->CpcInfo),
+ ARRAY_SIZE (PlatformRepo->CpcInfo),
+ Token,
+ GetCpcInfo,
+ CmObject
+ );
+ break;
+
default: {
Status = EFI_NOT_FOUND;
DEBUG ((
@@ -1788,6 +1853,151 @@ EDKII_CONFIGURATION_MANAGER_PROTOCOL ArmJunoPlatformConfigManagerProtocol = {
&ArmJunoPlatformRepositoryInfo
};


+/** Clear Cpc information.
+
+ If populating _CPC information fails, remove GicC tokens pointing
+ to Cpc CmObj to avoid creating corrupted _CPC objects.
+
+ @param [in] PlatformRepo Platfom Info repository.
+
+ @retval EFI_SUCCESS Success.
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+ClearCpcInfo (
+ EDKII_PLATFORM_REPOSITORY_INFO *PlatformRepo
+ )
+{
+ CM_ARM_GICC_INFO *GicCInfo;
+
+ GicCInfo = (CM_ARM_GICC_INFO*)&PlatformRepo->GicCInfo;
+
+ GicCInfo[0].CpcToken = CM_NULL_TOKEN;
+ GicCInfo[1].CpcToken = CM_NULL_TOKEN;
+ GicCInfo[2].CpcToken = CM_NULL_TOKEN;
+ GicCInfo[3].CpcToken = CM_NULL_TOKEN;
+ GicCInfo[4].CpcToken = CM_NULL_TOKEN;
+ GicCInfo[5].CpcToken = CM_NULL_TOKEN;
+
+ return EFI_SUCCESS;
+}
+
+/** Use the SCMI protocol to populate CPC objects dynamically.
+
+ @param [in] PlatformRepo Platfom Info repository.
+ @param [in] DomainId Id of the DVFS domain to probe.
+
+ @retval EFI_SUCCESS Success.
+ @retval EFI_INVALID_PARAMETER A parameter is invalid.
+ @retval EFI_UNSUPPORTED Not supported.
+ @retval !(EFI_SUCCESS) An error occured.
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+PopulateCpcInfo (
+ EDKII_PLATFORM_REPOSITORY_INFO *PlatformRepo,
+ IN UINT32 DomainId
+ )
+{
+ EFI_STATUS Status;
+ CM_ARM_GICC_INFO *GicCInfo;
+ AML_CPC_INFO *CpcInfo;
+
+ if ((PlatformRepo == NULL) ||
+ ((DomainId != PSD_BIG_DOMAIN_ID) &&
+ (DomainId != PSD_LITTLE_DOMAIN_ID))) {
+ Status = EFI_INVALID_PARAMETER;
+ ASSERT_EFI_ERROR (Status);
+ return Status;
+ }
+
+ if (PlatformRepo->JunoRevision != JUNO_REVISION_R2) {
+ /* Available frequencies are different on Juno R[0|1|2]. _CPC was
+ * only tested on Juno R2, so only enable support for this version.
+ */
+ Status = EFI_UNSUPPORTED;
+ return Status;
+ }
[SAMI] I think this check should be moved outside this function into InitializePlatformRepository() and 
if the Juno revision is not R2, the code in InitializePlatformRepository() should perform default
initialisation by calling ClearCpcInfo().
[/SAMI]

+
+ CpcInfo = &PlatformRepo->CpcInfo[DomainId];
+ GicCInfo = (CM_ARM_GICC_INFO*)&PlatformRepo->GicCInfo;
+
+ Status = DynamicTablesScmiInfoGetFastChannel (
+ PlatformRepo->PsdInfo[DomainId].Domain,
+ CpcInfo
+ );
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ /* CPPC must advertise performances on a 'continuous, abstract, unit-less
+ performance scale', i.e. CPU performances on an asymmetric platform
+ nust be represented on a unified scale.
+ CPU performance values are obtained from SCP through SCMI and advertised
+ to the OS via the _CPC objects. SCP currently maps performance requests
+ to frequency requests.
+ Thus, SCP must be modified to advertise (and correctly handle)
+ performance values on a unified scale.
+
+ Check that SCP is using a unified scale by checking that the advertised
+ lowest/nominal frequencies are not the default ones.
+ */
+ if (((DomainId == PSD_BIG_DOMAIN_ID) &&
+ (CpcInfo->LowestPerformanceInteger == 600000000) &&
+ (CpcInfo->NominalPerformanceInteger == 1000000000)) ||
+ ((DomainId == PSD_LITTLE_DOMAIN_ID) &&
+ (CpcInfo->LowestPerformanceInteger == 450000000) &&
+ (CpcInfo->NominalPerformanceInteger == 800000000))) {
+ return EFI_UNSUPPORTED;
+ }
+
+ // Juno R2's lowest/nominal frequencies.
+ // Nominal frequency != Highest frequency.
+ if (DomainId == PSD_BIG_DOMAIN_ID) {
+ CpcInfo->LowestFrequencyInteger = 600;
+ CpcInfo->NominalFrequencyInteger = 1000;
+ } else {
+ CpcInfo->LowestFrequencyInteger = 450;
+ CpcInfo->NominalFrequencyInteger = 800;
+ }
+
+ // The mapping Psd -> CPUs is available here.
+ if (DomainId == PSD_BIG_DOMAIN_ID) {
+ GicCInfo[0].CpcToken = (CM_OBJECT_TOKEN)CpcInfo;
+ GicCInfo[1].CpcToken = (CM_OBJECT_TOKEN)CpcInfo;
+ } else {
+ GicCInfo[2].CpcToken = (CM_OBJECT_TOKEN)CpcInfo;
+ GicCInfo[3].CpcToken = (CM_OBJECT_TOKEN)CpcInfo;
+ GicCInfo[4].CpcToken = (CM_OBJECT_TOKEN)CpcInfo;
+ GicCInfo[5].CpcToken = (CM_OBJECT_TOKEN)CpcInfo;
+ }
+
+ /*
+ Arm advises to use FFH to the following registers which uses AMU counters:
+ - ReferencePerformanceCounterRegister
+ - DeliveredPerformanceCounterRegister
+ Cf. Arm Functional Fixed Hardware Specification
+ s3.2 Performance management and Collaborative Processor Performance Control
+
+ AMU is not supported by the Juno, so clear these registers.
+ */
+ CpcInfo->ReferencePerformanceCounterRegister.AddressSpaceId = EFI_ACPI_6_5_SYSTEM_MEMORY;
+ CpcInfo->ReferencePerformanceCounterRegister.RegisterBitWidth = 0;
+ CpcInfo->ReferencePerformanceCounterRegister.RegisterBitOffset = 0;
+ CpcInfo->ReferencePerformanceCounterRegister.AccessSize = 0;
+ CpcInfo->ReferencePerformanceCounterRegister.Address = 0;
+
+ CpcInfo->DeliveredPerformanceCounterRegister.AddressSpaceId = EFI_ACPI_6_5_SYSTEM_MEMORY;
+ CpcInfo->DeliveredPerformanceCounterRegister.RegisterBitWidth = 0;
+ CpcInfo->DeliveredPerformanceCounterRegister.RegisterBitOffset = 0;
+ CpcInfo->DeliveredPerformanceCounterRegister.AccessSize = 0;
+ CpcInfo->DeliveredPerformanceCounterRegister.Address = 0;
+
+ return Status;
+}
+
/**
Entrypoint of Configuration Manager Dxe.


@@ -1807,6 +2017,8 @@ ConfigurationManagerDxeInitialize (
)
{
EFI_STATUS Status;
+ UINT32 Index;
+ BOOLEAN CpcFailed;


Status = gBS->InstallProtocolInterface (
&ImageHandle,
@@ -1821,7 +2033,7 @@ ConfigurationManagerDxeInitialize (
" Status = %r\n",
Status
));
- goto error_handler;
+ return Status;
}


Status = InitializePlatformRepository (
@@ -1836,6 +2048,21 @@ ConfigurationManagerDxeInitialize (
));
}


-error_handler:
- return Status;
+ CpcFailed = FALSE;
+ for (Index = 0; Index < PSD_DOMAIN_COUNT; Index++) {
+ Status = PopulateCpcInfo (&ArmJunoPlatformRepositoryInfo, Index);
+ if (EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_WARN, "WARN: Could not populate _CPC.\n"));
+ CpcFailed = TRUE;
+ break;
+ }
+ }
+
+ if (CpcFailed) {
+ // _CPC information is not mandatory and SCP might not support some
+ // SCMI requests. Failing should not prevent from booting.
+ ClearCpcInfo (&ArmJunoPlatformRepositoryInfo);
+ }
[SAMI] The above code should be moved in InitializePlatformRepository(). 
+
+ return EFI_SUCCESS;
}
diff --git a/Platform/ARM/JunoPkg/ConfigurationManager/ConfigurationManagerDxe/ConfigurationManager.h b/Platform/ARM/JunoPkg/ConfigurationManager/ConfigurationManagerDxe/ConfigurationManager.h
index e58e9cbecb23..fe3edd548faf 100644
--- a/Platform/ARM/JunoPkg/ConfigurationManager/ConfigurationManagerDxe/ConfigurationManager.h
+++ b/Platform/ARM/JunoPkg/ConfigurationManager/ConfigurationManagerDxe/ConfigurationManager.h
@@ -303,6 +303,9 @@ typedef struct PlatformRepositoryInfo {
// Power domains
CM_ARM_PSD_INFO PsdInfo[PSD_DOMAIN_COUNT];


+ // Cpc info (1 for each PSD domain)
+ CM_ARM_CPC_INFO CpcInfo[PSD_DOMAIN_COUNT];
+
/// Juno Board Revision
UINT32 JunoRevision;
} EDKII_PLATFORM_REPOSITORY_INFO;
diff --git a/Platform/ARM/JunoPkg/ConfigurationManager/ConfigurationManagerDxe/ConfigurationManagerDxe.inf b/Platform/ARM/JunoPkg/ConfigurationManager/ConfigurationManagerDxe/ConfigurationManagerDxe.inf
index 91bffe8d5d82..53060bf56531 100644
--- a/Platform/ARM/JunoPkg/ConfigurationManager/ConfigurationManagerDxe/ConfigurationManagerDxe.inf
+++ b/Platform/ARM/JunoPkg/ConfigurationManager/ConfigurationManagerDxe/ConfigurationManagerDxe.inf
@@ -35,6 +35,7 @@ [Packages]


[LibraryClasses]
ArmPlatformLib
+ DynamicTablesScmiInfoLib
PrintLib
UefiBootServicesTableLib
UefiDriverEntryPoint
-- 
2.25.1







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