Re: [PATCH v2 3/4] arm: add ISAR2, MMFR0 and MMFR1 fields in cpufeature

[Bertrand Marquis <Bertrand.Marquis@xxxxxxx>]

Hi Stefano,

> On 3 Jun 2022, at 02:45, Stefano Stabellini <sstabellini@xxxxxxxxxx> wrote:
> 
> On Tue, 31 May 2022, Bertrand Marquis wrote:
>> Complete AA64ISAR2 and AA64MMFR[0-1] with more fields.
>> While there add a comment for MMFR bitfields as for other registers in
>> the cpuinfo structure definition.
>> 
>> Signed-off-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
>> ---
>> Changes in v2:
>> - patch introduced to isolate changes in cpufeature.h
>> - complete MMFR0 and ISAR2 to sync with sysregs.h status
>> ---
>> xen/arch/arm/include/asm/cpufeature.h | 28 ++++++++++++++++++++++-----
>> 1 file changed, 23 insertions(+), 5 deletions(-)
>> 
>> diff --git a/xen/arch/arm/include/asm/cpufeature.h 
>> b/xen/arch/arm/include/asm/cpufeature.h
>> index 9649a7afee..57eb6773d3 100644
>> --- a/xen/arch/arm/include/asm/cpufeature.h
>> +++ b/xen/arch/arm/include/asm/cpufeature.h
>> @@ -234,6 +234,7 @@ struct cpuinfo_arm {
>> union {
>> register_t bits[3];
>> struct {
>> + /* MMFR0 */
>> unsigned long pa_range:4;
>> unsigned long asid_bits:4;
>> unsigned long bigend:4;
>> @@ -242,18 +243,31 @@ struct cpuinfo_arm {
>> unsigned long tgranule_16K:4;
>> unsigned long tgranule_64K:4;
>> unsigned long tgranule_4K:4;
>> - unsigned long __res0:32;
>> -
>> + unsigned long tgranule_16k_2:4;
>> + unsigned long tgranule_64k_2:4;
>> + unsigned long tgranule_4k:4;
> 
> Should be tgranule_4k_2:4

Right I will fix that.

> 
> 
>> + unsigned long exs:4;
>> + unsigned long __res0:8;
>> + unsigned long fgt:4;
>> + unsigned long ecv:4;
>> +
>> + /* MMFR1 */
>> unsigned long hafdbs:4;
>> unsigned long vmid_bits:4;
>> unsigned long vh:4;
>> unsigned long hpds:4;
>> unsigned long lo:4;
>> unsigned long pan:4;
>> - unsigned long __res1:8;
>> - unsigned long __res2:28;
>> + unsigned long specsei:4;
>> + unsigned long xnx:4;
>> + unsigned long twed:4;
>> + unsigned long ets:4;
>> + unsigned long __res1:4;
> 
> hcx?
> 
> 
>> + unsigned long afp:4;
>> + unsigned long __res2:12;
> 
> ntlbpa
> tidcp1
> cmow
> 
>> unsigned long ecbhb:4;
> 
> Strangely enough I am looking at DDI0487H and ecbhb is not there
> (D13.2.65). Am I looking at the wrong location?

Right now I declared here only the values which have a corresponding
declaration in sysregs.h
If I add more fields here we will not be in sync with it anymore.

And on ecbhb it will be in the next revision of the manual yes.


> 
> 
>> + /* MMFR2 */
>> unsigned long __res3:64;
>> };
>> } mm64;
>> @@ -297,7 +311,11 @@ struct cpuinfo_arm {
>> unsigned long __res2:8;
>> 
>> /* ISAR2 */
>> - unsigned long __res3:28;
>> + unsigned long wfxt:4;
>> + unsigned long rpres:4;
>> + unsigned long gpa3:4;
>> + unsigned long apa3:4;
>> + unsigned long __res3:12;
> 
> mops
> bc
> pac_frac
> 
> 
>> unsigned long clearbhb:4;
> 
> And again this is not described at D13.2.63. Probably the bhb stuff
> didn't make it into the ARM ARM yet.

As said before, are you ok with only adding stuff declared in sysregs
to make it simpler to sync with Linux ?

Cheers
Bertrand

> 
> 
>> 
>> unsigned long __res4:32;
>> -- 
>> 2.25.1