Re: [PATCH v5 2/9] iommu/arm-smmu-v3: Replace s1_cfg with cdtab_cfg

From: Will Deacon
Date: Wed Aug 09 2023 - 12:27:59 EST


On Wed, Aug 09, 2023 at 01:26:41PM -0300, Jason Gunthorpe wrote:
> On Wed, Aug 09, 2023 at 05:22:54PM +0100, Will Deacon wrote:
>
> > > > If we want to use 4k leaf tables in some cases, how would you add
> > > > that? Such a change shouldn't need the low-level strtab creation
> > > > code to change.
> > >
> > > You would modify arm_smmu_ctx_desc_cfg to teach it about the different
> > > format. It would gain some (enum?) member that specifies the CD table
> > > layout and geometry. arm_smmu_get_cd_ste() will interpret that member
> > > and generate the correct STE for the specifc cd table.
> >
> > Sounds a lot like the existing s1fmt field. Can we keep it?
>
> If you are OK with the dead code, I don't object. But let's put it in
> the struct arm_smmu_ctx_desc_cfg.

Ok, we have a deal!

Will