[PATCH 4/9] lib: sbi: Use finer permission sematics to decide on PMP bits

[Anup Patel]

On Tue, Dec 20, 2022 at 4:17 PM Himanshu Chauhan
<hchauhan at ventanamicro.com> wrote:
>
> Use the fine grained permission bits to decide if the region
> permissions are to enforced on all modes. Also use the new

s/are to/are to be/

> permission bits for deciding on R/W/X bits in pmpcfg register.
>
> Signed-off-by: Himanshu Chauhan <hchauhan at ventanamicro.com>

Otherwise, looks good to me.

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

Regards,
Anup

> ---
>  lib/sbi/sbi_hart.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
> index 5447c52..2ded55b 100644
> --- a/lib/sbi/sbi_hart.c
> +++ b/lib/sbi/sbi_hart.c
> @@ -303,14 +303,20 @@ int sbi_hart_pmp_configure(struct sbi_scratch *scratch)
>                         break;
>
>                 pmp_flags = 0;
> -               if (reg->flags & SBI_DOMAIN_MEMREGION_READABLE)
> +
> +               /*
> +                * If permissions are to be enforced for all modes on this region,
> +                * the lock bit should be set.
> +                */
> +               if (reg->flags & SBI_DOMAIN_MEMREGION_ENF_PERMISSIONS)
> +                       pmp_flags |= PMP_L;
> +
> +               if (reg->flags & SBI_DOMAIN_MEMREGION_SU_READABLE)
>                         pmp_flags |= PMP_R;
> -               if (reg->flags & SBI_DOMAIN_MEMREGION_WRITEABLE)
> +               if (reg->flags & SBI_DOMAIN_MEMREGION_SU_WRITABLE)
>                         pmp_flags |= PMP_W;
> -               if (reg->flags & SBI_DOMAIN_MEMREGION_EXECUTABLE)
> +               if (reg->flags & SBI_DOMAIN_MEMREGION_SU_EXECUTABLE)
>                         pmp_flags |= PMP_X;
> -               if (reg->flags & SBI_DOMAIN_MEMREGION_MMODE)
> -                       pmp_flags |= PMP_L;
>
>                 pmp_addr =  reg->base >> PMP_SHIFT;
>                 if (pmp_gran_log2 <= reg->order && pmp_addr < pmp_addr_max)
> --
> 2.39.0
>
>
> --
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