Re: [PATCH 4/5] lib: sbi: Extend hart protection abstraction to allow ID configuration

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

On Mon, Jul 20, 2026 at 04:19:10PM +0530, Anup Patel wrote:
> On Mon, Jul 20, 2026 at 3:40 PM Yu-Chien Peter Lin <peter.lin@sifive.com> wrote:
> >
> > Hi Anup and Raymond,
> >
> > On Fri, Jul 17, 2026 at 01:14:12PM +0530, Anup Patel wrote:
> > > There are various ID configuration ISA extensions such as RISC-V Worlds,
> > > Supervisor domain ID, QoS ID, etc which need to be re-configured upon
> > > domain context switch on a hart. Extend hart protection abstraction to
> > > support both memory protection and ID configuration ISA extensions.
> >
> > I will rework my "[RFC,00/12] Add RISC-V Worlds ISA support to OpenSBI"
> > series based on this series.
> 
> Thanks Peter!
> 
> The RISC-V world DT property parsing can be done at the
> time of parsing domains from FDT (like already done in this
> series). The hart platform abstraction will be only for configuring
> the RISC-V world CSRs.
> 
> May be you can add sbi_hart_worlds.c (just like sbi_hart_pmp.c) ?
> 
> For RISC-V world checkers, we can have separate FDT based driver
> under lib/utils which will register sbi_domain_data instance upon probe
> of each RISC-V world checker instance. The domain_setup() and
> domain_cleanup() callbacks of the RISC-V worlds checker driver will
> program the RISC-V world checker MMIO registers.

Sounds great, thanks for the direction. Will follow this approach and
update in v2.

Thanks,
Peter Lin

> 
> Regards,
> Anup
> 
> >
> > Thanks,
> > Peter Lin
> >
> > >
> > > Signed-off-by: Anup Patel <anup.patel@oss.qualcomm.com>
> > > ---
> > >  include/sbi/sbi_hart_protection.h | 16 +++++-
> > >  lib/sbi/sbi_hart_pmp.c            |  2 +
> > >  lib/sbi/sbi_hart_protection.c     | 94 ++++++++++++++++++++++++++-----
> > >  lib/sbi/sbi_init.c                |  2 +-
> > >  platform/generic/eswin/eic770x.c  |  1 +
> > >  5 files changed, 98 insertions(+), 17 deletions(-)
> > >
> > > diff --git a/include/sbi/sbi_hart_protection.h b/include/sbi/sbi_hart_protection.h
> > > index 5e170f05..1358b5be 100644
> > > --- a/include/sbi/sbi_hart_protection.h
> > > +++ b/include/sbi/sbi_hart_protection.h
> > > @@ -13,6 +13,13 @@
> > >  struct sbi_scratch;
> > >  struct sbi_domain;
> > >
> > > +/** Different types of hart protection mechanisms */
> > > +enum sbi_hart_protection_type {
> > > +     SBI_HART_PROTECTION_TYPE_MEMORY = 0,
> > > +     SBI_HART_PROTECTION_TYPE_ID,
> > > +     SBI_HART_PROTECTIOn_TYPE_MAX
> > > +};
> > > +
> > >  /** Representation of hart protection mechanism */
> > >  struct sbi_hart_protection {
> > >       /** List head */
> > > @@ -21,6 +28,9 @@ struct sbi_hart_protection {
> > >       /** Name of the hart protection mechanism */
> > >       char name[32];
> > >
> > > +     /** Type of the hart protection mechanism */
> > > +     enum sbi_hart_protection_type type;
> > > +
> > >       /** Ratings of the hart protection mechanism (higher is better) */
> > >       unsigned long rating;
> > >
> > > @@ -40,11 +50,11 @@ struct sbi_hart_protection {
> > >  };
> > >
> > >  /**
> > > - * Get the best hart protection mechanism
> > > + * Get the best hart memory protection mechanism
> > >   *
> > > - * @return pointer to best hart protection mechanism
> > > + * @return pointer to best hart memory protection mechanism
> > >   */
> > > -struct sbi_hart_protection *sbi_hart_protection_best(void);
> > > +struct sbi_hart_protection *sbi_hart_memory_protection_best(void);
> > >
> > >  /**
> > >   * Register a hart protection mechanism
> > > diff --git a/lib/sbi/sbi_hart_pmp.c b/lib/sbi/sbi_hart_pmp.c
> > > index 5ede3cc1..c0a4ce1b 100644
> > > --- a/lib/sbi/sbi_hart_pmp.c
> > > +++ b/lib/sbi/sbi_hart_pmp.c
> > > @@ -425,6 +425,7 @@ static void sbi_hart_pmp_unconfigure(struct sbi_scratch *scratch,
> > >  static struct sbi_hart_protection pmp_protection = {
> > >       .name = "pmp",
> > >       .rating = 100,
> > > +     .type = SBI_HART_PROTECTION_TYPE_MEMORY,
> > >       .configure = sbi_hart_oldpmp_configure,
> > >       .unconfigure = sbi_hart_pmp_unconfigure,
> > >  };
> > > @@ -432,6 +433,7 @@ static struct sbi_hart_protection pmp_protection = {
> > >  static struct sbi_hart_protection epmp_protection = {
> > >       .name = "epmp",
> > >       .rating = 200,
> > > +     .type = SBI_HART_PROTECTION_TYPE_MEMORY,
> > >       .configure = sbi_hart_smepmp_configure,
> > >       .unconfigure = sbi_hart_pmp_unconfigure,
> > >       .map_range = sbi_hart_smepmp_map_range,
> > > diff --git a/lib/sbi/sbi_hart_protection.c b/lib/sbi/sbi_hart_protection.c
> > > index fecefde8..d31e9938 100644
> > > --- a/lib/sbi/sbi_hart_protection.c
> > > +++ b/lib/sbi/sbi_hart_protection.c
> > > @@ -10,12 +10,16 @@
> > >
> > >  static SBI_LIST_HEAD(hart_protection_list);
> > >
> > > -struct sbi_hart_protection *sbi_hart_protection_best(void)
> > > +struct sbi_hart_protection *sbi_hart_memory_protection_best(void)
> > >  {
> > > -     if (sbi_list_empty(&hart_protection_list))
> > > -             return NULL;
> > > +     struct sbi_hart_protection *pos;
> > >
> > > -     return sbi_list_first_entry(&hart_protection_list, struct sbi_hart_protection, head);
> > > +     sbi_list_for_each_entry(pos, &hart_protection_list, head) {
> > > +             if (pos->type == SBI_HART_PROTECTION_TYPE_MEMORY)
> > > +                     return pos;
> > > +     }
> > > +
> > > +     return NULL;
> > >  }
> > >
> > >  int sbi_hart_protection_register(struct sbi_hart_protection *hprot)
> > > @@ -74,33 +78,97 @@ static void __hart_protection_unconfigure(struct sbi_scratch *scratch,
> > >  int sbi_hart_protection_configure(struct sbi_scratch *scratch,
> > >                                 struct sbi_domain *dom)
> > >  {
> > > -     return __hart_protection_configure(scratch, sbi_hart_protection_best(), dom);
> > > +     bool do_configure, memory_protect_done = false;
> > > +     struct sbi_hart_protection *hprot;
> > > +     int ret;
> > > +
> > > +     sbi_list_for_each_entry(hprot, &hart_protection_list, head) {
> > > +             do_configure = false;
> > > +             switch (hprot->type) {
> > > +             case SBI_HART_PROTECTION_TYPE_MEMORY:
> > > +                     do_configure = !memory_protect_done;
> > > +                     memory_protect_done = true;
> > > +                     break;
> > > +             case SBI_HART_PROTECTION_TYPE_ID:
> > > +                     do_configure = true;
> > > +                     break;
> > > +             default:
> > > +                     break;
> > > +             }
> > > +             if (!do_configure)
> > > +                     continue;
> > > +
> > > +             ret = __hart_protection_configure(scratch, hprot, dom);
> > > +             if (ret)
> > > +                     return ret;
> > > +     }
> > > +
> > > +     return 0;
> > >  }
> > >
> > >  void sbi_hart_protection_unconfigure(struct sbi_scratch *scratch,
> > >                                    struct sbi_domain *dom)
> > >  {
> > > -     __hart_protection_unconfigure(scratch, sbi_hart_protection_best(), dom);
> > > +
> > > +     bool do_unconfigure, memory_protect_done = false;
> > > +     struct sbi_hart_protection *hprot;
> > > +
> > > +     sbi_list_for_each_entry(hprot, &hart_protection_list, head) {
> > > +             do_unconfigure = false;
> > > +             switch (hprot->type) {
> > > +             case SBI_HART_PROTECTION_TYPE_MEMORY:
> > > +                     do_unconfigure = !memory_protect_done;
> > > +                     memory_protect_done = true;
> > > +                     break;
> > > +             case SBI_HART_PROTECTION_TYPE_ID:
> > > +                     do_unconfigure = true;
> > > +                     break;
> > > +             default:
> > > +                     break;
> > > +             }
> > > +             if (!do_unconfigure)
> > > +                     continue;
> > > +
> > > +             __hart_protection_unconfigure(scratch, hprot, dom);
> > > +     }
> > >  }
> > >
> > >  int sbi_hart_protection_reconfigure(struct sbi_scratch *scratch,
> > >                                   struct sbi_domain *current_dom,
> > >                                   struct sbi_domain *next_dom)
> > >  {
> > > -     struct sbi_hart_protection *hprot = sbi_hart_protection_best();
> > > +     bool do_reconfigure, memory_protect_done = false;
> > > +     struct sbi_hart_protection *hprot;
> > >       int ret;
> > >
> > > -     __hart_protection_unconfigure(scratch, hprot, current_dom);
> > > -     ret = __hart_protection_configure(scratch, hprot, next_dom);
> > > -     if (ret)
> > > -             return ret;
> > > +     sbi_list_for_each_entry(hprot, &hart_protection_list, head) {
> > > +             do_reconfigure = false;
> > > +             switch (hprot->type) {
> > > +             case SBI_HART_PROTECTION_TYPE_MEMORY:
> > > +                     do_reconfigure = !memory_protect_done;
> > > +                     memory_protect_done = true;
> > > +                     break;
> > > +             case SBI_HART_PROTECTION_TYPE_ID:
> > > +                     do_reconfigure = true;
> > > +                     break;
> > > +             default:
> > > +                     break;
> > > +             }
> > > +             if (!do_reconfigure)
> > > +                     continue;
> > > +
> > > +             __hart_protection_unconfigure(scratch, hprot, current_dom);
> > > +             ret = __hart_protection_configure(scratch, hprot, next_dom);
> > > +             if (ret)
> > > +                     return ret;
> > > +     }
> > >
> > >       return 0;
> > >  }
> > >
> > >  int sbi_hart_protection_map_range(unsigned long base, unsigned long size)
> > >  {
> > > -     struct sbi_hart_protection *hprot = sbi_hart_protection_best();
> > > +     struct sbi_hart_protection *hprot = sbi_hart_memory_protection_best();
> > >
> > >       if (!hprot || !hprot->map_range)
> > >               return 0;
> > > @@ -110,7 +178,7 @@ int sbi_hart_protection_map_range(unsigned long base, unsigned long size)
> > >
> > >  int sbi_hart_protection_unmap_range(unsigned long base, unsigned long size)
> > >  {
> > > -     struct sbi_hart_protection *hprot = sbi_hart_protection_best();
> > > +     struct sbi_hart_protection *hprot = sbi_hart_memory_protection_best();
> > >
> > >       if (!hprot || !hprot->unmap_range)
> > >               return 0;
> > > diff --git a/lib/sbi/sbi_init.c b/lib/sbi/sbi_init.c
> > > index d74dc67c..3f1f136a 100644
> > > --- a/lib/sbi/sbi_init.c
> > > +++ b/lib/sbi/sbi_init.c
> > > @@ -93,7 +93,7 @@ static void sbi_boot_print_general(struct sbi_scratch *scratch)
> > >       sbi_printf("Platform Features           : %s\n", str);
> > >       sbi_printf("Platform HART Count         : %u\n",
> > >                  sbi_platform_hart_count(plat));
> > > -     hprot = sbi_hart_protection_best();
> > > +     hprot = sbi_hart_memory_protection_best();
> > >       sbi_printf("Platform HART Protection    : %s\n",
> > >                  (hprot) ? hprot->name : "---");
> > >       idev = sbi_ipi_get_device();
> > > diff --git a/platform/generic/eswin/eic770x.c b/platform/generic/eswin/eic770x.c
> > > index da4d0e34..c71198a8 100644
> > > --- a/platform/generic/eswin/eic770x.c
> > > +++ b/platform/generic/eswin/eic770x.c
> > > @@ -470,6 +470,7 @@ static void eswin_eic7700_pmp_unconfigure(struct sbi_scratch *scratch,
> > >  static struct sbi_hart_protection eswin_eic7700_pmp_protection = {
> > >       .name = "eic7700_pmp",
> > >       .rating = -1UL,
> > > +     .type = SBI_HART_PROTECTION_TYPE_MEMORY,
> > >       .configure = eswin_eic7700_pmp_configure,
> > >       .unconfigure = eswin_eic7700_pmp_unconfigure,
> > >  };

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