linux-kernel - Re: [PATCH 7/8] arm64: cpufeature: Relax checks for AArch32 support at EL[0-2]

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Message-ID: <714f124c-7eb7-b750-e98c-63da64ddae75@arm.com>
Date:   Wed, 15 Apr 2020 11:50:58 +0100
From:   Suzuki K Poulose <suzuki.poulose@....com>
To:     will@...nel.org, linux-arm-kernel@...ts.infradead.org,
        kvmarm@...ts.cs.columbia.edu
Cc:     linux-kernel@...r.kernel.org, mark.rutland@....com, maz@...nel.org,
        anshuman.khandual@....com, catalin.marinas@....com,
        saiprakash.ranjan@...eaurora.org, dianders@...omium.org,
        kernel-team@...roid.com
Subject: Re: [PATCH 7/8] arm64: cpufeature: Relax checks for AArch32 support
 at EL[0-2]

On 04/14/2020 10:31 PM, Will Deacon wrote:
> We don't need to be quite as strict about mismatched AArch32 support,
> which is good because the friendly hardware folks have been busy
> mismatching this to their hearts' content.
> 
>    * We don't care about EL2 or EL3 (there are silly comments concerning
>      the latter, so remove those)
> 
>    * EL1 support is gated by the ARM64_HAS_32BIT_EL1 capability and handled
>      gracefully when a mismatch occurs
> 
>    * EL1 support is gated by the ARM64_HAS_32BIT_EL0 capability and handled

s/EL1/EL0

>      gracefully when a mismatch occurs
> 
> Relax the AArch32 checks to FTR_NONSTRICT.

Agreed. We should do something similar for the features exposed by the
ELF_HWCAP, of course in a separate series.

> 
> Signed-off-by: Will Deacon <will@...nel.org>

Reviewed-by: Suzuki K Poulose <suzuki.poulose@....com>