[PATCH V3] arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9

[Anshuman Khandual]

On 3/12/25 09:16, Anshuman Khandual wrote:
> 
> 
> On 3/11/25 22:47, Catalin Marinas wrote:
>> On Thu, 27 Feb 2025 09:21:19 +0530, Anshuman Khandual wrote:
>>> FEAT_PMUv3p9 registers such as PMICNTR_EL0, PMICFILTR_EL0, and PMUACR_EL1
>>> access from EL1 requires appropriate EL2 fine grained trap configuration
>>> via FEAT_FGT2 based trap control registers HDFGRTR2_EL2 and HDFGWTR2_EL2.
>>> Otherwise such register accesses will result in traps into EL2.
>>>
>>> Add a new helper __init_el2_fgt2() which initializes FEAT_FGT2 based fine
>>> grained trap control registers HDFGRTR2_EL2 and HDFGWTR2_EL2 (setting the
>>> bits nPMICNTR_EL0, nPMICFILTR_EL0 and nPMUACR_EL1) to enable access into
>>> PMICNTR_EL0, PMICFILTR_EL0, and PMUACR_EL1 registers.
>>>
>>> [...]
>>
>> Applied to arm64 (for-next/el2-enable-feat-pmuv3p9), thanks!
>>
>> [1/1] arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9
>>       https://git.kernel.org/arm64/c/858c7bfcb35e
>>
>> I removed Cc: stable since, if it gets backported automatically, it will
>> miss the sysreg updates and break the build. Please send it to stable
>> directly once it lands upstream, together with the dependencies.
> 
> Sure, will do that.
> 

Just FYI,

This patch along with required tools sysreg patches are merged in applicable
stable branches which are now available in v6.12.25 and v6.14.4 respectively.