Re: [PATCH] arm/smmu: Complete SMR masking support

[Julien Grall <julien@xxxxxxx>]

Hi,


On 12/09/2024 17:59, Rahul Singh wrote:
> > On 4 Sep 2024, at 1:43 PM, Michal Orzel <michal.orzel@xxxxxxx> wrote:
> >
> > SMR masking support allows deriving a mask either using a 2-cell iommu
> > specifier (per master) or stream-match-mask SMMU dt property (global
> > config). Even though the mask is stored in the fwid when adding a
> > device (in arm_smmu_dt_xlate_generic()), we still set it to 0 when
> > allocating SMEs (in arm_smmu_master_alloc_smes()). So at the end, we
> > always ignore the mask when programming SMRn registers. This leads to
> > SMMU failures. Fix it by completing the support.
> >
> > A bit of history:
> > Linux support for SMR allocation was mainly done with:
> > 588888a7399d ("iommu/arm-smmu: Intelligent SMR allocation")
> > 021bb8420d44 ("iommu/arm-smmu: Wire up generic configuration support")
> >
> > Taking the mask into account in arm_smmu_master_alloc_smes() was added
> > as part of the second commit, although quite hidden in the thicket of
> > other changes. We backported only the first patch with: 0435784cc75d
> > ("xen/arm: smmuv1: Intelligent SMR allocation") but the changes to take
> > the mask into account were missed.
> >
> > Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>
> Reviewed-by: Rahul Singh <rahul.singh@xxxxxxx>
Committed.

Cheers,

--
Julien Grall