[RFC PATCH 09/12] platform: generic: parse root domain WID config from DT

[Yu-Chien Peter Lin]

On Wed, Jul 08, 2026 at 05:39:34PM -0700, Pawandeep Oza wrote:
> On Fri, Jun 26, 2026 at 3:17 AM Yu-Chien Peter Lin <peter.lin at sifive.com> wrote:
> >
> > Parse root-domain-next-wid (32-bit) and root-domain-next-widlist
> > (64-bit) properties from /chosen/opensbi,config node during
> > generic_domains_init(). Sets root.next_wid/has_next_wid and
> > root.next_widlist.
> >
> > Signed-off-by: Yu-Chien Peter Lin <peter.lin at sifive.com>
> > ---
> >  platform/generic/platform.c | 20 +++++++++++++++++++-
> >  1 file changed, 19 insertions(+), 1 deletion(-)
> >
> > diff --git a/platform/generic/platform.c b/platform/generic/platform.c
> > index 51e9f342..de12deb5 100644
> > --- a/platform/generic/platform.c
> > +++ b/platform/generic/platform.c
> > @@ -11,6 +11,7 @@
> >  #include <platform_override.h>
> >  #include <sbi/riscv_asm.h>
> >  #include <sbi/sbi_bitops.h>
> > +#include <sbi/sbi_domain.h>
> >  #include <sbi/sbi_hartmask.h>
> >  #include <sbi/sbi_heap.h>
> >  #include <sbi/sbi_platform.h>
> > @@ -276,7 +277,9 @@ int generic_extensions_init(bool cold_boot)
> >  int generic_domains_init(void)
> >  {
> >         const void *fdt = fdt_get_address();
> > -       int offset, ret;
> > +       const fdt32_t *val;
> > +       int len, offset, ret;
> > +       u64 val64;
> >
> >         ret = fdt_domains_populate(fdt);
> >         if (ret < 0)
> > @@ -290,6 +293,21 @@ int generic_domains_init(void)
> >                 if (offset >= 0 &&
> >                     fdt_get_property(fdt, offset, "system-suspend-test", NULL))
> >                         sbi_system_suspend_test_enable();
> > +
> > +               if (offset >= 0) {
> > +                       val = fdt_getprop(fdt, offset, "root-domain-next-wid", &len);
> > +                       if (val && len == sizeof(fdt32_t)) {
> > +                               root.next_wid = fdt32_to_cpu(val[0]);
> > +                               root.has_next_wid = true;
> > +                       }
> > +
> > +                       val = fdt_getprop(fdt, offset, "root-domain-next-widlist", &len);
> Oza: Root domain WID config is semantically identical to per-domain
> WID config but lives in a completely different DT location
> root can be another default domain under chosen { opensbi-domains {

Sure, it would be better to have root domain wid configuration
specified under the opensbi-domain parent node alongside other
domains. I also am planning to introduce "opensbi,domain,instance,root"
compatible string.

Thanks,
Peter Lin

> > +                       if (val && (len == (2 * sizeof(fdt32_t)))) {
> > +                               val64 = fdt32_to_cpu(val[0]);
> > +                               val64 = (val64 << 32) | fdt32_to_cpu(val[1]);
> > +                               root.next_widlist = val64;
> > +                       }
> > +               }
> >         }
> >
> >         return 0;
> > --
> > 2.43.7
> >
> >
> > --
> > opensbi mailing list
> > opensbi at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/opensbi