Re: [PATCH v3 02/10] arm/domain: Get rid of READ/WRITE_SYSREG32

[Michal Orzel <michal.orzel@xxxxxxx>]

Hi Julien,

On 05.05.2021 20:03, Julien Grall wrote:
> Hi Michal,
> 
> On 05/05/2021 08:43, Michal Orzel wrote:
>> AArch64 registers are 64bit whereas AArch32 registers
>> are 32bit or 64bit. MSR/MRS are expecting 64bit values thus
>> we should get rid of helpers READ/WRITE_SYSREG32
>> in favour of using READ/WRITE_SYSREG.
>> We should also use register_t type when reading sysregs
>> which can correspond to uint64_t or uint32_t.
>> Even though many AArch64 registers have upper 32bit reserved
>> it does not mean that they can't be widen in the future.
>>
>> Modify type of register cntkctl to register_t.
>>
>> Modify accesses to thumbee registers to use READ/WRITE_SYSREG.
>> Thumbee registers are only usable by a 32bit domain and in fact
>> should be only accessed on ARMv7 as they were retrospectively dropped
>> on ARMv8.
> 
> Sorry for not replying on v2. How about:
> 
> "
> Thumbee registers are only usable by a 32-bit domain and therefore we can 
> just store the bottom 32-bit (IOW there is no type change). In fact, this 
> could technically be restricted to Armv7 HW (the support was dropped 
> retrospectively in Armv8) but leave it as-is for now.
> "
> 
> If you are happy with it, I will do it on commit.
> 
I am happy with it. Please ack and change it on commit.
Thanks.
> Cheers,
> 

Cheers,
Michal