[PATCH v2 3/9] lib: fdt_domain: parse domain WID properties

[Pawandeep Oza]

On Mon, Aug 17, 2026 at 2:05 AM Yu-Chien Peter Lin <peter.lin at sifive.com> wrote:
>
> Add wid and widdeleg fields to struct sbi_domain to store the
> RISC-V Worlds mlwid and mwideleg CSR values for each domain.
> Also, parse the root and user-defined domains' WID during
> fdt_domains_populate().
>
> Signed-off-by: Yu-Chien Peter Lin <peter.lin at sifive.com>
> ---
> Changes v1 -> v2:
> - Add root subnode for root domain configuration (Oza and Anup)
> - Rename next_wid/widlist to wid/widdeleg (Oza)
> ---
>  include/sbi/sbi_domain.h   |  6 +++++
>  lib/utils/fdt/fdt_domain.c | 50 ++++++++++++++++++++++++++++++++++++++
>  2 files changed, 56 insertions(+)
>
> diff --git a/include/sbi/sbi_domain.h b/include/sbi/sbi_domain.h
> index 16edd4ce..44c8befc 100644
> --- a/include/sbi/sbi_domain.h
> +++ b/include/sbi/sbi_domain.h
> @@ -215,6 +215,12 @@ struct sbi_domain {
>         bool system_reset_allowed;
>         /** Is domain allowed to suspend the system */
>         bool system_suspend_allowed;
> +       /** World ID for this domain (mlwid value) */
> +       u32 wid;
> +       /** Whether World ID was explicitly set */
> +       bool has_wid;
Oza: again here you may be able to find out if wid == UINT_MAX then
wid is not set. because we have finite number of N wolrds so max is N
-1 ?
you can then drop bool has_wid;

> +       /** World ID delegation bitmask for this domain (mwiddeleg value) */
> +       u64 widdeleg;
>         /** Identifies whether to include the firmware region */
>         bool fw_region_inited;
>  };
> diff --git a/lib/utils/fdt/fdt_domain.c b/lib/utils/fdt/fdt_domain.c
> index 61627db3..68dd6da4 100644
> --- a/lib/utils/fdt/fdt_domain.c
> +++ b/lib/utils/fdt/fdt_domain.c
> @@ -307,6 +307,27 @@ static int __fdt_parse_region(const void *fdt, int domain_offset,
>         return 0;
>  }
>
> +static void fdt_parse_domain_wid_props(const void *fdt, int offset,
> +                                      struct sbi_domain *dom)
> +{
> +       const fdt32_t *val;
> +       int len;
> +       u64 val64;
> +
> +       val = fdt_getprop(fdt, offset, "wid", &len);
> +       if (val && len == sizeof(fdt32_t)) {
> +               dom->wid = fdt32_to_cpu(val[0]);
> +               dom->has_wid = true;
> +       }
> +
> +       val = fdt_getprop(fdt, offset, "widdeleg", &len);
> +       if (val && (len == (2 * sizeof(fdt32_t)))) {
> +               val64 = fdt32_to_cpu(val[0]);
> +               val64 = (val64 << 32) | fdt32_to_cpu(val[1]);
> +               dom->widdeleg = val64;
> +       }
> +}
> +
>  static int __fdt_parse_domain(const void *fdt, int domain_offset, void *opaque)
>  {
>         u32 val32;
> @@ -469,6 +490,9 @@ static int __fdt_parse_domain(const void *fdt, int domain_offset, void *opaque)
>         }
>         dom->next_mode = val32;
>
> +       /* Read "wid" and "widdeleg" DT properties */
> +       fdt_parse_domain_wid_props(fdt, domain_offset, dom);
> +
>         /* Read "system-reset-allowed" DT property */
>         if (fdt_get_property(fdt, domain_offset,
>                              "system-reset-allowed", NULL))
> @@ -535,6 +559,29 @@ fail_free_domain:
>         return err;
>  }
>
> +static void fdt_parse_root_domain(const void *fdt)
> +{
> +       int offset;
> +
> +       if (!fdt)
> +               return;
> +
> +       offset = fdt_path_offset(fdt, "/chosen");
> +       if (offset < 0)
> +               return;
> +
> +       offset = fdt_node_offset_by_compatible(fdt, offset,
> +                                              "opensbi,domain,config");
> +       if (offset < 0)
> +               return;
> +
> +       offset = fdt_subnode_offset(fdt, offset, "root");
> +       if (offset < 0)
> +               return;
> +
> +       fdt_parse_domain_wid_props(fdt, offset, &root);
> +}
> +
>  int fdt_domains_populate(const void *fdt)
>  {
>         const u32 *val;
> @@ -573,6 +620,9 @@ int fdt_domains_populate(const void *fdt)
>                 break;
>         }
>
> +       /* Parse root domain config from "root" subnode */
> +       fdt_parse_root_domain(fdt);
> +
>         /* Iterate over each domain in FDT and populate details */
>         return fdt_iterate_each_domain_ro(fdt, &cold_domain_offset,
>                                           __fdt_parse_domain);
> --
> 2.43.7
>