[PATCH v4 22/29] arm64: add Permission Overlay Extension Kconfig

[Anshuman Khandual]

On 5/3/24 18:31, Joey Gouly wrote:
> Now that support for POE and Protection Keys has been implemented, add a
> config to allow users to actually enable it.
> 
> Signed-off-by: Joey Gouly <joey.gouly at arm.com>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Will Deacon <will at kernel.org>

Reviewed-by: Anshuman Khandual <anshuman.khandual at arm.com>

> ---
>  arch/arm64/Kconfig | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 7b11c98b3e84..676ebe4bf9eb 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -2095,6 +2095,28 @@ config ARM64_EPAN
>  	  if the cpu does not implement the feature.
>  endmenu # "ARMv8.7 architectural features"
>  
> +menu "ARMv8.9 architectural features"

Agree with Kevin regarding need for an empty line here.

> +config ARM64_POE
> +	prompt "Permission Overlay Extension"
> +	def_bool y
> +	select ARCH_USES_HIGH_VMA_FLAGS
> +	select ARCH_HAS_PKEYS
> +	help
> +	  The Permission Overlay Extension is used to implement Memory
> +	  Protection Keys. Memory Protection Keys provides a mechanism for
> +	  enforcing page-based protections, but without requiring modification
> +	  of the page tables when an application changes protection domains.
> +
> +	  For details, see Documentation/core-api/protection-keys.rst
> +
> +	  If unsure, say y.
> +
> +config ARCH_PKEY_BITS
> +	int
> +	default 3
> +
> +endmenu # "ARMv8.9 architectural features"
> +
>  config ARM64_SVE
>  	bool "ARM Scalable Vector Extension support"
>  	default y