[PATCH v3 02/22] arm64: Generate sign macro for sysreg Enums

Ben Horgan ben.horgan at arm.com
Fri Jun 27 02:04:21 PDT 2025


Hi Colton,

On 6/26/25 21:04, Colton Lewis wrote:
> There's no reason Enums shouldn't be equivalent to UnsignedEnums and
> explicitly specify they are unsigned. This will avoid the annoyance I
> had with HPMN0.
An Enum can be annotated with the field's sign by updating it to 
UnsignedEnum or SignedEnum. This is explained in [1].

With this change ID_AA64PFR1_EL1.MTE_frac would be marked as unsigned 
when it should really be considered signed.

Enum	43:40	MTE_frac
	0b0000	ASYNC
	0b1111	NI
EndEnum


> 
> Signed-off-by: Colton Lewis <coltonlewis at google.com>
> ---
>   arch/arm64/tools/gen-sysreg.awk | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm64/tools/gen-sysreg.awk b/arch/arm64/tools/gen-sysreg.awk
> index f2a1732cb1f6..fa21a632d9b7 100755
> --- a/arch/arm64/tools/gen-sysreg.awk
> +++ b/arch/arm64/tools/gen-sysreg.awk
> @@ -308,6 +308,7 @@ $1 == "Enum" && (block_current() == "Sysreg" || block_current() == "SysregFields
>   	parse_bitdef(reg, field, $2)
>   
>   	define_field(reg, field, msb, lsb)
> +	define_field_sign(reg, field, "false")
>   
>   	next
>   }

Thanks,

Ben

[1] 
https://lore.kernel.org/all/20221207-arm64-sysreg-helpers-v4-1-25b6b3fb9d18@kernel.org/




More information about the linux-arm-kernel mailing list