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

[Yu-Chien Peter Lin <peter.lin@sifive.com>]

Hi Oza,

On Thu, Sep 03, 2026 at 02:18:48PM -0700, Pawandeep Oza wrote:
> On Mon, Aug 17, 2026 at 2:05 AM Yu-Chien Peter Lin <peter.lin@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@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;

Agreed, will drop in next patch version.

Thanks,
Peter Lin

> 
> > +       /** 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
> >

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