Re: [PATCH v5 5/7] iommu/arm-smmu-v3: Populate smmu_domain->invs when attaching masters

Nicolin Chen
2025-11-24T23:19:56Z

On Mon, Nov 24, 2025 at 07:13:41PM -0400, Jason Gunthorpe wrote:
> On Mon, Nov 24, 2025 at 09:43:18PM +0000, Will Deacon wrote:
> > > + /*
> > > + * We are committed to updating the STE. Ensure the invalidation array
> > > + * is visable to concurrent map/unmap threads, and acquire any racying
> > > + * IOPTE updates.
> > > + */
> > > + smp_mb();
> >
> > Sorry, but the comment hasn't really helped me here. We're ordering the
> > publishing of the invalidation array above before ... what?
>
> "concurrent map/unmap threads" means other threads calling
> arm_smmu_iotlb_sync().. I think the matching comment describing this
> and introducing the pair'd smp_mb() is in a later patch.
...
> Nicolin maybe this barrier line should be moved to be added in the
> patch that add's the pair'd barrier and description?

Sure. I can move that to PATCH-6.

Thanks
Nicolin