[RFC PATCH 35/36] arm64: nmi: Add Kconfig for NMI

[Jinjie Ruan]

On 7/9/2026 8:13 PM, Vladimir Murzin wrote:
> From: Mark Brown <broonie at kernel.org>
> 
> Since NMI handling is in some fairly hot paths we provide a Kconfig
> option which allows support to be compiled out when not needed.
> 
> Signed-off-by: Mark Brown <broonie at kernel.org>
> Signed-off-by: Ada Couprie Diaz <ada.coupriediaz at arm.com>
> Signed-off-by: Vladimir Murzin <vladimir.murzin at arm.com>
> ---
>  arch/arm64/Kconfig | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index e36dc4831200..968a9d97549a 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -2195,6 +2195,24 @@ endmenu # "ARMv8.7 architectural features"
>  config AS_HAS_MOPS
>  	def_bool $(as-instr,.arch_extension mops)
>  
> +menu "ARMv8.8 architectural features"
> +
> +config ARM64_NMI
> +	bool "Enable support for Non-maskable Interrupts (NMI)"

We should depends on ARM_GIC_V3 as FEAT_NMI is only valid when
FEAT_GICv3_NMI implemented.


> +	default y
> +	help
> +	  Non-maskable interrupts are an architecture and GIC feature
> +	  which allow the system to configure some interrupts to be
> +	  configured to have superpriority, allowing them to be handled
> +	  before other interrupts and masked for shorter periods of time.
> +
> +	  The feature is detected at runtime, and will remain disabled
> +	  if the cpu does not implement the feature. It will also be
> +	  disabled if pseudo NMIs are enabled at runtime.
> +
> +endmenu # "ARMv8.8 architectural features"
> +
> +
>  menu "ARMv8.9 architectural features"
>  
>  config ARM64_POE