[PATCH v2 26/37] arm64: mte: Convert gcr_user into an exclude mask

[Catalin Marinas]

On Tue, Sep 15, 2020 at 11:16:08PM +0200, Andrey Konovalov wrote:
> From: Vincenzo Frascino <vincenzo.frascino at arm.com>
> 
> The gcr_user mask is a per thread mask that represents the tags that are
> excluded from random generation when the Memory Tagging Extension is
> present and an 'irg' instruction is invoked.
> 
> gcr_user affects the behavior on EL0 only.
> 
> Currently that mask is an include mask and it is controlled by the user
> via prctl() while GCR_EL1 accepts an exclude mask.
> 
> Convert the include mask into an exclude one to make it easier the
> register setting.
> 
> Note: This change will affect gcr_kernel (for EL1) introduced with a
> future patch.
> 
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino at arm.com>
> Signed-off-by: Andrey Konovalov <andreyknvl at google.com>

Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>