Re: [PATCH v6 06/13] arm64/cpufeature: detect pointer authentication

[Richard Henderson]

On 12/7/18 12:39 PM, Kristina Martsenko wrote:
> From: Mark Rutland <mark.rutland@xxxxxxx>
> 
> So that we can dynamically handle the presence of pointer authentication
> functionality, wire up probing code in cpufeature.c.
> 
> From ARMv8.3 onwards, ID_AA64ISAR1 is no longer entirely RES0, and now
> has four fields describing the presence of pointer authentication
> functionality:
> 
> * APA - address authentication present, using an architected algorithm
> * API - address authentication present, using an IMP DEF algorithm
> * GPA - generic authentication present, using an architected algorithm
> * GPI - generic authentication present, using an IMP DEF algorithm
> 
> This patch checks for both address and generic authentication,
> separately. It is assumed that if all CPUs support an IMP DEF algorithm,
> the same algorithm is used across all CPUs.
> 
> Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
> Signed-off-by: Kristina Martsenko <kristina.martsenko@xxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> ---
>  arch/arm64/include/asm/cpucaps.h    |  8 +++-
>  arch/arm64/include/asm/cpufeature.h | 12 +++++
>  arch/arm64/kernel/cpufeature.c      | 90 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 109 insertions(+), 1 deletion(-)

Reviewed-by: Richard Henderson <richard.henderson@xxxxxxxxxx>


r~