[PATCH 6/7] lib: utils: Copy over restricted root domain memregions to FDT domains

[Alistair Francis]

On Sat, 2021-04-10 at 12:48 +0530, Anup Patel wrote:
> We should copy over all restricted memregions from the root domain
> to the domains populated from FDT. These restricted root memregions
> are typically firmware memregion and M-mode only mmio memregions.
> 
> Signed-off-by: Anup Patel <anup.patel at wdc.com>

Reviewed-by: Alistair Francis <alistair.francis at wdc.com>

Alistair

> ---
>  lib/utils/fdt/fdt_domain.c | 26 ++++++++++++++++++++++----
>  1 file changed, 22 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/utils/fdt/fdt_domain.c b/lib/utils/fdt/fdt_domain.c
> index 09615e5..95c195d 100644
> --- a/lib/utils/fdt/fdt_domain.c
> +++ b/lib/utils/fdt/fdt_domain.c
> @@ -222,7 +222,7 @@ static u32 fdt_domains_count;
>  static struct sbi_domain fdt_domains[FDT_DOMAIN_MAX_COUNT];
>  static struct sbi_hartmask fdt_masks[FDT_DOMAIN_MAX_COUNT];
>  static struct sbi_domain_memregion
> -       fdt_regions[FDT_DOMAIN_MAX_COUNT][FDT_DOMAIN_REGION_MAX_COUNT +
> 2];
> +       fdt_regions[FDT_DOMAIN_MAX_COUNT][FDT_DOMAIN_REGION_MAX_COUNT +
> 1];
>  
>  static int __fdt_parse_region(void *fdt, int domain_offset,
>                               int region_offset, u32 region_access,
> @@ -276,7 +276,7 @@ static int __fdt_parse_domain(void *fdt, int
> domain_offset, void *opaque)
>         struct sbi_hartmask *mask;
>         struct sbi_hartmask assign_mask;
>         int *cold_domain_offset = opaque;
> -       struct sbi_domain_memregion *regions;
> +       struct sbi_domain_memregion *reg, *regions;
>         int i, err, len, cpus_offset, cpu_offset, doffset;
>  
>         /* Sanity check on maximum domains we can handle */
> @@ -314,13 +314,31 @@ static int __fdt_parse_domain(void *fdt, int
> domain_offset, void *opaque)
>         /* Setup memregions from DT */
>         val32 = 0;
>         sbi_memset(regions, 0,
> -                  sizeof(*regions) * (FDT_DOMAIN_REGION_MAX_COUNT +
> 2));
> +                  sizeof(*regions) * (FDT_DOMAIN_REGION_MAX_COUNT +
> 1));
>         dom->regions = regions;
>         err = fdt_iterate_each_memregion(fdt, domain_offset, &val32,
>                                          __fdt_parse_region);
>         if (err)
>                 return err;
> -       sbi_domain_memregion_initfw(&regions[val32]);
> +
> +       /*
> +        * Copy over root domain memregions which don't allow
> +        * read, write and execute from lower privilege modes.
> +        *
> +        * These root domain memregions without read, write,
> +        * and execute permissions include:
> +        * 1) firmware region protecting the firmware memory
> +        * 2) mmio regions protecting M-mode only mmio devices
> +        */
> +       sbi_domain_for_each_memregion(&root, reg) {
> +               if ((reg->flags & SBI_DOMAIN_MEMREGION_READABLE) ||
> +                   (reg->flags & SBI_DOMAIN_MEMREGION_WRITEABLE) ||
> +                   (reg->flags & SBI_DOMAIN_MEMREGION_EXECUTABLE))
> +                       continue;
> +               if (FDT_DOMAIN_REGION_MAX_COUNT <= val32)
> +                       return SBI_EINVAL;
> +               sbi_memcpy(&regions[val32++], reg, sizeof(*reg));
> +       }
>  
>         /* Read "boot-hart" DT property */
>         val32 = -1U;