[PATCH 2/3] lib: utils/fdt/fdt_domain: Simplify region access permission check

[Anup Patel]

On Fri, Feb 24, 2023 at 10:01 AM Bin Meng <bmeng at tinylab.org> wrote:
>
> The region access permission check in __fdt_parse_region() can be
> simplified as masking SBI_DOMAIN_MEMREGION_{M,SU}_ACCESS_MASK is
> enough.
>
> While we are here, update the confusing comments to match the codes.
>
> Signed-off-by: Bin Meng <bmeng at tinylab.org>

Looks good to me.

Reviewed-by: Anup Patel <anup at brainfault.org>

Applied this patch to the riscv/opensbi repo.

Thanks,
Anup

> ---
>
>  lib/utils/fdt/fdt_domain.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/lib/utils/fdt/fdt_domain.c b/lib/utils/fdt/fdt_domain.c
> index 2b51a8e..bc30010 100644
> --- a/lib/utils/fdt/fdt_domain.c
> +++ b/lib/utils/fdt/fdt_domain.c
> @@ -244,13 +244,11 @@ static int __fdt_parse_region(void *fdt, int domain_offset,
>          * access permissions. M-mode regions can only be part of
>          * root domain.
>          *
> -        * SU permission bits can't be all zeroes and M-mode permission
> -        * bits must be all set.
> +        * SU permission bits can't be all zeroes when M-mode permission
> +        * bits have at least one bit set.
>          */
> -       if (!((region_access & SBI_DOMAIN_MEMREGION_SU_ACCESS_MASK)
> -            & SBI_DOMAIN_MEMREGION_SU_RWX)
> -           && ((region_access & SBI_DOMAIN_MEMREGION_M_ACCESS_MASK)
> -               & SBI_DOMAIN_MEMREGION_M_RWX))
> +       if (!(region_access & SBI_DOMAIN_MEMREGION_SU_ACCESS_MASK)
> +           && (region_access & SBI_DOMAIN_MEMREGION_M_ACCESS_MASK))
>                 return SBI_EINVAL;
>
>         /* Find next region of the domain */
> --
> 2.25.1
>