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

Ben Horgan
2025-06-27T09:04:27Z

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@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]