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

From: Will Deacon
Date: Mon May 18 2020 - 13:00:05 EST


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).

Will