Re: [PATCH 2/2] drivers/arm-smmu-v3: Implement .iotlb_sync_map callback

Jason Gunthorpe
2025-09-29T12:47:23Z

On Mon, Sep 29, 2025 at 12:24:28PM +0000, Mostafa Saleh wrote:
> On Mon, Sep 29, 2025 at 08:58:03AM -0300, Jason Gunthorpe wrote:
> > On Sat, Sep 27, 2025 at 10:39:53PM +0000, Daniel Mentz wrote:
> > > @@ -3700,6 +3713,7 @@ static const struct iommu_ops arm_smmu_ops = {
> > > .map_pages = arm_smmu_map_pages,
> > > .unmap_pages = arm_smmu_unmap_pages,
> > > .flush_iotlb_all = arm_smmu_flush_iotlb_all,
> > > + .iotlb_sync_map = arm_smmu_iotlb_sync_map,
> >
> > Shouldn't this avoid defining the op on coherent systems?
>
> Does that mean we need to have 2 iommu_ops, one for
> coherent/non-coherent SMMUs, as both can be mixed in the same system.

Yes, I think you'd have to do it with two ops..

It just seems wrong to penalize the normal fast case for these
systems.

Jason