Re: [PATCH 4/7] iommu/arm-smmu: Support buggy implementations where all config accesses are secure

[Andreas Herrmann <andreas.herrmann-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>]

On Thu, Oct 10, 2013 at 11:47:27AM -0400, Will Deacon wrote:
> On Wed, Oct 09, 2013 at 11:38:03PM +0100, Andreas Herrmann wrote:
> > In such a case we have to use secure aliases of some non-secure
> > registers.
> > 
> > This handling is switched on by DT property
> > "arm,smmu-secure-config-access" for an SMMU node.
> > 
> > Signed-off-by: Andreas Herrmann <andreas.herrmann-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>
> > ---
> >  drivers/iommu/arm-smmu.c |   30 +++++++++++++++++++++---------
> >  1 file changed, 21 insertions(+), 9 deletions(-)
> > 
> > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> > index f877d02..91316a8 100644
> > --- a/drivers/iommu/arm-smmu.c
> > +++ b/drivers/iommu/arm-smmu.c
> > @@ -51,6 +51,7 @@
> >  /* Driver options */
> >  #define ARM_SMMU_OPT_ISOLATE_DEVICES		(1 << 0)
> >  #define ARM_SMMU_OPT_MASK_STREAM_IDS		(1 << 1)
> > +#define ARM_SMMU_OPT_SECURE_CONFIG_ACCESS	(1 << 2)
> >  
> >  /* Maximum number of stream IDs assigned to a single device */
> >  #define MAX_MASTER_STREAMIDS		8
> > @@ -65,6 +66,15 @@
> >  #define ARM_SMMU_GR0(smmu)		((smmu)->base)
> >  #define ARM_SMMU_GR1(smmu)		((smmu)->base + (smmu)->pagesize)
> >  
> > +/*
> > + * SMMU global address space with conditional offset to access secure aliases of
> > + * non-secure registers (e.g. nsCR0: 0x400, nsGFSR: 0x448, nsGFSYNR0: 0x450)
> > + */
> > +#define ARM_SMMU_GR0_NS(smmu)						\
> > +	((smmu)->base +							\
> > +		((smmu->options & ARM_SMMU_OPT_SECURE_CONFIG_ACCESS)	\
> > +			? 0x400 : 0))
> 
> You have a slight issue with the ordering of your patches, as this macro is
> used by the stream masking patch, but this patch is based on top of the
> latter.
> 
> Can you introduce this patch first please? I think it's ok for merging, but
> I still have reservations with the other one.

Oops, I've done some shuffling to update the first patch in the
series. Obviously I mixed something up during this.

I'll fix this asap.


Andreas