[PATCH 3/5] lib: utils: Improve fdt_cpu_fixup() implementation

[Anup Patel]

> -----Original Message-----
> From: Atish Patra <atishp at atishpatra.org>
> Sent: 11 September 2020 06:35
> To: Anup Patel <Anup.Patel at wdc.com>
> Cc: Atish Patra <Atish.Patra at wdc.com>; Alistair Francis
> <Alistair.Francis at wdc.com>; Anup Patel <anup at brainfault.org>; OpenSBI
> <opensbi at lists.infradead.org>
> Subject: Re: [PATCH 3/5] lib: utils: Improve fdt_cpu_fixup() implementation
> 
> On Wed, Sep 9, 2020 at 7:51 AM Anup Patel <anup.patel at wdc.com> wrote:
> >
> > The fdt_cpu_fixup() should work fine even if HARTs without MMU are not
> > marked invalid by platform support code.
> >
> > In future, we plan to treat HARTs without MMU as valid in the generic
> > platform support so that we can hold these HARTs in HSM STOPPED state.
> >
> > Signed-off-by: Anup Patel <anup.patel at wdc.com>
> > ---
> >  lib/utils/fdt/fdt_fixup.c | 13 +++++++++++--
> >  1 file changed, 11 insertions(+), 2 deletions(-)
> >
> > diff --git a/lib/utils/fdt/fdt_fixup.c b/lib/utils/fdt/fdt_fixup.c
> > index 4da7397..8f554e1 100644
> > --- a/lib/utils/fdt/fdt_fixup.c
> > +++ b/lib/utils/fdt/fdt_fixup.c
> > @@ -21,7 +21,8 @@ void fdt_cpu_fixup(void *fdt)  {
> >         struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
> >         const struct sbi_platform *plat = sbi_platform_ptr(scratch);
> > -       int err, cpu_offset, cpus_offset;
> > +       int err, cpu_offset, cpus_offset, len;
> > +       const char *mmu_type;
> >         u32 hartid;
> >
> >         err = fdt_open_into(fdt, fdt, fdt_totalsize(fdt) + 32); @@
> > -37,7 +38,15 @@ void fdt_cpu_fixup(void *fdt)
> >                 if (err)
> >                         continue;
> >
> > -               if (sbi_platform_hart_invalid(plat, hartid))
> > +               /*
> > +                * Disable a HART DT node if one of the following is true:
> > +                * 1. The HART is marked invalid by platform support
> > +                * 2. MMU is not available for the HART
> > +                */
> > +
> > +               mmu_type = fdt_getprop(fdt, cpu_offset, "mmu-type", &len);
> > +               if (sbi_platform_hart_invalid(plat, hartid) ||
> > +                   !mmu_type || !len)
> >                         fdt_setprop_string(fdt, cpu_offset, "status",
> >                                            "disabled");
> >         }
> > --
> > 2.25.1
> >
> >
> > --
> > opensbi mailing list
> > opensbi at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/opensbi
> 
> 
> Reviewed-by: Atish Patra <atish.patra at wdc.com>

Applied this patch to the riscv/opensbi repo

Regards,
Anup