[PATCH 0/8] ARM: Expose Armv8 AArch32 features via hwcap

[Amit Daniel Kachhap]

On 11/22/22 00:34, Russell King (Oracle) wrote:
> On Wed, Oct 26, 2022 at 11:19:53AM +0530, Amit Daniel Kachhap wrote:
>> Hi All,
>> 
>> This series advertise availability of Armv8 features present in
>> AArch32 state. These features are mostly Advanced SIMD(fphp,
>> asimdhp, dp, fhm, bf16, i8mm) and few others(sb ssbs). These
>> features are already exposed to user in arm64 kernel. A similar
>> series advertising the features in arm64 kernel in compat mode will
>> be sent separately.
>> 
>> Some other remaining features(SPECRES,  ETS, nTLBPA, CSV3, LSMAOC)
>> are not advertised in arm64 kernel so left here also.
>> 
>> The entire series is divided feature wise as present in Armv8
>> manual. The details of these features can be found in Armv8
>> architecture reference manual available from 
>> https://developer.arm.com/documentation/ddi0487/gb/?lang=en
>> 
>> All the changes have been tested on Arm FVP Base Revc model after
>> adding necessary model parameters.
>> 
>> The series is based on Linux 6.1-rc1.
> 
> Hi Amit,
> 
> Please could you list which CPUs support running aarch32 _and_
> support these features?
> 
> Thanks!

Hi Russell,

Below are some of the cpus representing these AArch32 features. This
list is not exhaustive enough and can be found in the respective
processor manual.


Features-

fp16(fphp+asimdhp):
Architectures       - v8.2(optional)
AArch32 Processor   - Cortex A75 and A55 at all el, A710 and Neoverse N2 
at el0 only

dp:
Architectures       - v8.2(optional), v8.4(mandatory)
AArch32 Processor   - Cortex A75 and A55 at all el, A710 and Neoverse N2 
at el0 only

fhm:
Architectures       - v8.2(optional), v8.4(mandatory)
AArch32 Processor   - Cortex A710 and Neoverse N2 at el0 only

aa32bf16:
Architectures       - v8.2(optional)
AArch32 Processor   - Cortex A710 and Neoverse N2 at el0 only

aa32i8mm:
Architectures       - v8.2(optional), v8.4(mandatory)
AArch32 Processor   - Cortex A710 and Neoverse N2 at el0 only

sb:
Architectures       - v8.0(optional),v8.5(Mandatory)
AArch32 Processor   - Cortex A710 and Neoverse N2 at el0 only

ssbs:
Architectures       - v8.0(Optional), v8.5(Mandatory)
AArch32 Processor   - Cortex A76, A710 and Neoverse N2 at el0 only

Thanks,
Amit


>