Re: [PATCH V2] arm64/cpufeature: Drop open encodings while extracting parange

[Will Deacon]

On Mon, May 18, 2020 at 05:59:59PM +0100, Will Deacon wrote:
> On Wed, May 13, 2020 at 02:33:34PM +0530, Anshuman Khandual wrote:
> > Currently there are multiple instances of parange feature width mask open
> > encodings while fetching it's value. Even the width mask value (0x7) itself
> > is not accurate. It should be (0xf) per ID_AA64MMFR0_EL1.PARange[3:0] as in
> > ARM ARM (0487F.a). Replace them with cpuid_feature_extract_unsigned_field()
> > which can extract given standard feature (4 bits width i.e 0xf mask) field.
> > 
> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> > Cc: Will Deacon <will@xxxxxxxxxx>
> > Cc: Marc Zyngier <maz@xxxxxxxxxx>
> > Cc: James Morse <james.morse@xxxxxxx>
> > Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx
> > Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> > Cc: linux-kernel@xxxxxxxxxxxxxxx
> > 
> > Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> > ---
> > Changes in V2:
> > 
> > - Used cpuid_feature_extract_unsigned_field() per Mark
> > 
> > Changes in V1: (https://patchwork.kernel.org/patch/11541913/)
> > 
> >  arch/arm64/kernel/cpufeature.c |  3 ++-
> >  arch/arm64/kvm/reset.c         | 11 ++++++++---
> >  2 files changed, 10 insertions(+), 4 deletions(-)
> 
> Acked-by: Will Deacon <will@xxxxxxxxxx>
> 
> I'm assuming Marc will take this, but let me know if it should go via arm64
> instead (where we have a bunch of other cpufeature stuff queued).

Hmm, but having just spotted [1], it looks like we might need a bit of
co-ordination here. Marc?

Will

[1] https://lore.kernel.org/r/1589248647-22925-1-git-send-email-anshuman.khandual@xxxxxxx