Re: [PATCH] ARM: decompressor: Fix mmu mapping for non-DRAM address space.

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On Wed, May 9, 2012 at 4:40 PM, Russell King - ARM Linux
<linux@xxxxxxxxxxxxxxxx> wrote:
>
> On Wed, May 09, 2012 at 03:44:08PM -0500, Buckley, Bryan wrote:
> > On Wed, May 9, 2012 at 10:48 AM, Russell King - ARM Linux
> > <linux@xxxxxxxxxxxxxxxx> wrote:
> > >
> > > On Wed, May 09, 2012 at 06:00:10PM +0530, Shilimkar, Santosh wrote:
> > > > On Wed, May 9, 2012 at 5:53 PM, Russell King - ARM Linux
> > > > <linux@xxxxxxxxxxxxxxxx> wrote:
> > > > > On Wed, May 09, 2012 at 02:20:28PM +0530, Shilimkar, Santosh wrote:
> > > > >> The only change done common code is  clearing 'XN' bit for DRAM
> > > > >> region in page table entries. The other change of setting the DACR
> > > > >> register is done in ARMv7 specific code.
> > > > >
> > > > > Yes, XN is an ARMv6+ thing.  Before ARMv5, it was implementation defined.
> > > > >
> > > > > Some implementations used the bit to mean "allow writes to update the
> > > > > cache".  Other implementations labelled this bit as "should be zero"
> > > > > while others labelled it as "should be one".
> > > > >
> > > > Good to know.
> > > >
> > > > > The upshot of this is, we know that having this bit as '1' means that
> > > > > all the CPUs we support today work.  I would be _very_ concerned to
> > > > > change this bit to zero as we _really_ don't know how the pre-ARMv6
> > > > > CPUs would react.
> > > > >
> > > > I agree.
> > > >
> > > > > The solution to this is pretty simple - if ARMv6+ needs a different
> > > > > base section mapping value, then we need to extract that from the code
> > > > > and pass in the base section mapping value.
> > > > >
> > > > > I'll sort out a patch later today for this.
> > > > Great.
> > >
> > > This works for my 4430SDP board.  I haven't booted it on anything else yet.
> > > Please can you check that this solves the issue for you?  Thanks.
> > >
> >
> > Solves the issue for OMAP5. Thanks Russel and company.
>
> Can I add this attributation for this patch:
>
> Tested-by: Bryan Buckley <bryan.buckley@xxxxxx>
>
> ?

If still applicable, yes that is fine.

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