Re: [PATCH] riscv: Do not invoke early_init_dt_verify() twice

From: Changbin Du
Date: Thu Mar 25 2021 - 11:56:55 EST


On Wed, Mar 24, 2021 at 08:51:06PM +0530, Anup Patel wrote:
> On Wed, Mar 24, 2021 at 8:33 PM Changbin Du <changbin.du@xxxxxxxxx> wrote:
> >
> > In the setup_arch() of riscv, function early_init_dt_verify() has
> > been done by parse_dtb(). So no need to call it again. Just directly
> > invoke unflatten_device_tree().
> >
> > Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
> > ---
> > arch/riscv/kernel/setup.c | 5 +----
> > 1 file changed, 1 insertion(+), 4 deletions(-)
> >
> > diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> > index f8f15332caa2..2a3d487e1710 100644
> > --- a/arch/riscv/kernel/setup.c
> > +++ b/arch/riscv/kernel/setup.c
> > @@ -255,10 +255,7 @@ void __init setup_arch(char **cmdline_p)
> > #if IS_ENABLED(CONFIG_BUILTIN_DTB)
> > unflatten_and_copy_device_tree();
> > #else
> > - if (early_init_dt_verify(__va(dtb_early_pa)))
> > - unflatten_device_tree();
> > - else
> > - pr_err("No DTB found in kernel mappings\n");
> > + unflatten_device_tree();
> > #endif
>
> The early_init_dt_verify() set he DTB base address in Linux OF.
>
> When parse_dtb() calls early_init_dt_verify(), MMU is enabled but
> we have temporary mapping for DTB (i.e. dtb_early_va).
>
> After paging_init(), we have moved to final swapper_pg_dir so
> temporary mapping for DTB does not exists anymore but DTB
> is at same physical address so update DTB base address in
> Linux OF by calling early_init_dt_verify() again.
>
> Based on above, NACK to this patch.
>
No problem, thanks!

> Regards,
> Anup
>
> > misc_mem_init();
> >
> > --
> > 2.30.2
> >
> >
> > _______________________________________________
> > linux-riscv mailing list
> > linux-riscv@xxxxxxxxxxxxxxxxxxx
> > http://lists.infradead.org/mailman/listinfo/linux-riscv

--
Cheers,
Changbin Du