Re: [edk2-devel] [PATCH v2 11/11] DynamicTablesPkg: Remove check for _CPC field

["PierreGondois" <pierre.gondois@arm.com>]

On 10/26/23 13:05, Leif Lindholm wrote:
> On Wed, Oct 25, 2023 at 13:25:40 +0200, pierre.gondois@arm.com wrote:
>> From: Pierre Gondois <pierre.gondois@arm.com>
>>
>> When generating _CPC objects, some fields are mandatory.
> 
> Mandatory by spec or mandatory by current API?
> If the former, could we either warn or add a Pcd to enable the more
> lenient behaviour?

They are mandatory by spec. These are actually the fields that are not
described as optional in:
    8.4.6.1 _CPC (Continuous Performance Control)
E.g.: 'Time Window Register': 'Optional. If supported, contains ...'

I will add a warning to signal them.

Regards,
Pierre

> 
> /
>      Leif
> 
>> Some fields cannot be supported by a the Juno platform, which is used
>> to test the _CPC generation. Therefore, don't prevent from generating
>> _CPC objects if the fields below are missing, and let the OS handle
>> the missing information.
>>
>> _CPC fields that are exempted from checks:
>> - PerformanceLimitedRegister
>> - ReferencePerformanceCounterRegister
>> - DeliveredPerformanceCounterRegister
>>
>> Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
>> ---
>>   .../Common/AmlLib/CodeGen/AmlCodeGen.c        | 19 +++++++++++++++----
>>   1 file changed, 15 insertions(+), 4 deletions(-)
>>
>> diff --git a/DynamicTablesPkg/Library/Common/AmlLib/CodeGen/AmlCodeGen.c b/DynamicTablesPkg/Library/Common/AmlLib/CodeGen/AmlCodeGen.c
>> index f350083b148c..423e64f12606 100644
>> --- a/DynamicTablesPkg/Library/Common/AmlLib/CodeGen/AmlCodeGen.c
>> +++ b/DynamicTablesPkg/Library/Common/AmlLib/CodeGen/AmlCodeGen.c
>> @@ -3531,6 +3531,11 @@ AmlCreateCpcNode (
>>       return EFI_INVALID_PARAMETER;
>>     }
>>   
>> +  // The following fields are theoretically mandatory, but not supported
>> +  // by some platforms. Don't check them:
>> +  // - PerformanceLimitedRegister
>> +  // - ReferencePerformanceCounterRegister
>> +  // - DeliveredPerformanceCounterRegister
>>     if ((IsNullGenericAddress (&CpcInfo->HighestPerformanceBuffer) &&
>>          (CpcInfo->HighestPerformanceInteger == 0)) ||
>>         (IsNullGenericAddress (&CpcInfo->NominalPerformanceBuffer) &&
>> @@ -3539,13 +3544,19 @@ AmlCreateCpcNode (
>>          (CpcInfo->LowestNonlinearPerformanceInteger == 0)) ||
>>         (IsNullGenericAddress (&CpcInfo->LowestPerformanceBuffer) &&
>>          (CpcInfo->LowestPerformanceInteger == 0)) ||
>> -      IsNullGenericAddress (&CpcInfo->DesiredPerformanceRegister) ||
>> -      IsNullGenericAddress (&CpcInfo->ReferencePerformanceCounterRegister) ||
>> -      IsNullGenericAddress (&CpcInfo->DeliveredPerformanceCounterRegister) ||
>> -      IsNullGenericAddress (&CpcInfo->PerformanceLimitedRegister))
>> +      IsNullGenericAddress (&CpcInfo->DesiredPerformanceRegister))
>>     {
>>       ASSERT (0);
>>       return EFI_INVALID_PARAMETER;
>> +  } else if ((IsNullGenericAddress (&CpcInfo->HighestPerformanceBuffer) &&
>> +              (CpcInfo->HighestPerformanceInteger == 0)) ||
>> +             (IsNullGenericAddress (&CpcInfo->NominalPerformanceBuffer) &&
>> +              (CpcInfo->NominalPerformanceInteger == 0)))
>> +  {
>> +    DEBUG ((
>> +      DEBUG_WARN,
>> +      "Missing Reference|Delivered performance field in _CPC object\n"
>> +      ));
>>     }
>>   
>>     CpcPackage = NULL;
>> -- 
>> 2.25.1
>>


-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#110517): https://edk2.groups.io/g/devel/message/110517
Mute This Topic: https://groups.io/mt/102175822/7686176
Group Owner: devel+owner@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io]
-=-=-=-=-=-=-=-=-=-=-=-