[PATCH] ARM: vector_table: Fix creation of second level page table

[Sascha Hauer]

On Wed, Aug 24, 2016 at 09:07:22AM -0700, Andrey Smirnov wrote:
> On Wed, Aug 24, 2016 at 5:23 AM, Sascha Hauer <s.hauer at pengutronix.de> wrote:
> > The second level page tables can only start at a 1MiB section boundary,
> > so instead of calling arm_create_pte() with the high vector address
> > (which is 0xffff0000, not 1MiB aligned) we have to call it with
> > 0xfff00000 to correctly create a second level page table. The vectors
> > themselves worked as expected with the old value, but the memory around
> > it did not do a 1:1 mapping anymore. This breaks SoCs which have
> > peripherals in that area, for example Atmel SoCs like the AT91RM9200.
> >
> 
> Would you mind re-wording it as something to the effect of: "...
> mapping anymore, breaking SoCs which also have peripherals in that
> area..."? The original sentence structure, to me, reads as if this
> patch/commit introduces a change that breaks Atmel SoCs.

Sure.

> 
> > Fixes: f6b77fe9: ARM: Rework vector table setup
> >
> > Reported-by: Peter Kardos <kardos.peter.sk at gmail.com>
> > Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
> > ---
> >  arch/arm/cpu/mmu.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/arm/cpu/mmu.c b/arch/arm/cpu/mmu.c
> > index a31bce4..2b70866 100644
> > --- a/arch/arm/cpu/mmu.c
> > +++ b/arch/arm/cpu/mmu.c
> > @@ -307,7 +307,7 @@ static void create_vector_table(unsigned long adr)
> >                 vectors = xmemalign(PAGE_SIZE, PAGE_SIZE);
> >                 pr_debug("Creating vector table, virt = 0x%p, phys = 0x%08lx\n",
> >                          vectors, adr);
> > -               exc = arm_create_pte(adr);
> > +               exc = arm_create_pte(adr & ~(SZ_1M - 1));
> 
> ALIGN_DOWN(adr, SZ_1M) ?

Yes, that's better. I just sent an updated version.

Sascha

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