Re: [PATCH v10 01/30] arm64/sysreg: Update SMIDR_EL1 to DDI0601 2025-06

[Mark Rutland <mark.rutland@arm.com>]

On Fri, Mar 06, 2026 at 05:00:53PM +0000, Mark Brown wrote:
> Update the definition of SMIDR_EL1 in the sysreg definition to reflect the
> information in DD0601 2025-06. This includes somewhat more generic ways of
> describing the sharing of SMCUs, more information on supported priorities
> and provides additional resolution for describing affinity groups.

FWIW, these are all in ARM DDI 0487 M.b:

  https://developer.arm.com/documentation/ddi0487/mb/

Is anything later in the series going to depend on these fields, or
would everything behave correctly with the existing RES0 field
definitions?

> Reviewed-by: Fuad Tabba <tabba@google.com>
> Signed-off-by: Mark Brown <broonie@kernel.org>
> ---
>  arch/arm64/tools/sysreg | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg
> index 9d1c21108057..b6586accf344 100644
> --- a/arch/arm64/tools/sysreg
> +++ b/arch/arm64/tools/sysreg
> @@ -3655,11 +3655,15 @@ Field	3:0	BS
>  EndSysreg
>  
>  Sysreg	SMIDR_EL1	3	1	0	0	6
> -Res0	63:32
> +Res0	63:60
> +Field	59:56	NSMC
> +Field	55:52	HIP

Reading the ARM ARM, HIP is arguably a backwards-incompatible change.

Do we expect to expose that to VMs, or just hide priorities entirely? I
suspect we probably want to require that the guest sees
SMIDR_EL1.SMPS==0, and not care about any of that.

Mark.

> +Field	51:32	AFFINITY2
>  Field	31:24	IMPLEMENTER
>  Field	23:16	REVISION
>  Field	15	SMPS
> -Res0	14:12
> +Field	14:13	SH
> +Res0	12
>  Field	11:0	AFFINITY
>  EndSysreg
>  
> 
> -- 
> 2.47.3
>