Re: [Xen-devel] [PATCH 2/3] mwait-idle: add support for AMD processors

["Woods, Brian" <Brian.Woods@xxxxxxx>]

On 3/13/19 4:42 AM, Jan Beulich wrote:
>>>> On 25.02.19 at 21:23, <Brian.Woods@xxxxxxx> wrote:
>> Newer AMD processors (F17h) have mwait support.  Add some checks to make
>> sure vendor specific code is run correctly and some infrastructure to
>> facilitate adding AMD processors.
> 
> Both my Fam15 and my Fam10 system have CPUID[1].ECX[3] set - why
> the reference to Fam17 here?

We added CPUID_Fn00000005_EDX to match Intel starting with F17h M01h 
(Naples).  Therefore going forward, we're just enabling with Naples and 
further processors.

Noted about other comments.

Brian

>> @@ -1115,6 +1122,9 @@ static void __init sklh_idle_state_table_update(void)
>>    */
>>   static void __init mwait_idle_state_table_update(void)
>>   {
>> +    if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
>> +            return;
> 
> Please use != INTEL here.
> 
>> @@ -1126,13 +1136,24 @@ static void __init 
>> mwait_idle_state_table_update(void)
>>      case 0x5e: /* SKL-H */
>>              sklh_idle_state_table_update();
>>              break;
>> -    }
>> +    }
>>   }
>>   
>>   static int __init mwait_idle_probe(void)
>>   {
>>      unsigned int eax, ebx, ecx;
>> -    const struct x86_cpu_id *id = x86_match_cpu(intel_idle_ids);
>> +    const struct x86_cpu_id *id;
>> +
>> +    switch (boot_cpu_data.x86_vendor) {
>> +    case X86_VENDOR_INTEL:
>> +            id = x86_match_cpu(intel_idle_ids);
>> +            break;
>> +    case X86_VENDOR_AMD:
>> +            id = x86_match_cpu(amd_idle_ids);
>> +            break;
>> +    default:
>> +            id = NULL;
>> +    }
> 
> Missing break statement again, but perhaps even better here to drop
> the default: and make NULL the variable's initializer.
> 
> Jan
> 
> 

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel