[PATCH 3/4] arm64: sysreg: Mark fields the architecture dropped as RES0

[Steffen Eiden]

On Tue, Oct 13, 2026 at 02:02:46PM +0100, Fuad Tabba wrote:
> Commit d65bf6e317e7 ("KVM: arm64: Remove all traces of FEAT_TME")
> turned the TME fields of SCTLR_EL1 into RES0, but left their copies in
> SCTLRMASK_EL1. PMICFILTR_EL0.T and BRBFCR_EL1.LASTFAILED have gone from
> the architecture as well. All six fields are RES0 in DDI0601 2026-09.
> 
> Mark them RES0 to match the spec. Nothing in the tree refers to them.
> 
> Signed-off-by: Fuad Tabba <fuad.tabba at linux.dev>

Verified values with DDI0601 2026-09.

While checking I noticed that Bit 58 of PMICFILTR_EL0 is also defined as
RES0 in DDI0601 2026-09 but is defined as SYNC in tools/sysreg. Not sure
if this demands a separate patch or can be folded into this one as you
already are touching this reg. This field is unused as well.

Anyways, 

Reviewed-by: Steffen Eiden <seiden at linux.ibm.com>

Steffen

> ---
>  arch/arm64/tools/sysreg | 11 +++--------
>  1 file changed, 3 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg
> index 341db8e9b6c37..99af1c39478be 100644
> --- a/arch/arm64/tools/sysreg
> +++ b/arch/arm64/tools/sysreg
> @@ -1420,8 +1420,7 @@ Field	17	DIRECT
>  Field	16	EnI
>  Res0	15:8
>  Field	7	PAUSED
> -Field	6	LASTFAILED
> -Res0	5:0
> +Res0	6:0
>  EndSysreg
>  
>  Sysreg	BRBTS_EL1	2	1	9	0	2
> @@ -2663,11 +2662,7 @@ Field	57	EPAN
>  Field	56	EnALS
>  Field	55	EnAS0
>  Field	54	EnASR
> -Field	53	TME
> -Field	52	TME0
> -Field	51	TMT
> -Field	50	TMT0
> -Res0	49:47
> +Res0	53:47
>  Field	46	TWEDEL
>  Field	45	TWEDEn
>  Field	44	DSSBS
> @@ -2985,7 +2980,7 @@ Field	27	NSH
>  Field	26	M
>  Res0	25
>  Field	24	SH
> -Field	23	T
> +Res0	23
>  Field	22	RLK
>  Field	21	RLU
>  Field	20	RLH
> -- 
> 2.39.5
>