Hi Nicolin,
On Tue, Jul 15, 2025 at 11:42:24AM -0700, Nicolin Chen wrote:
> Sorry for the late response.
No problem at all.
> On Fri, Jul 11, 2025 at 05:14:27PM +0100, Will Deacon wrote:
> > > /* MMIO registers */
> > > #define ARM_SMMU_IDR0 0x0
> > > @@ -720,6 +721,10 @@ struct arm_smmu_impl_ops {
> > > int (*init_structures)(struct arm_smmu_device *smmu);
> > > struct arm_smmu_cmdq *(*get_secondary_cmdq)(
> > > struct arm_smmu_device *smmu, struct arm_smmu_cmdq_ent *ent);
> > > + const size_t vsmmu_size;
> > > + const enum iommu_viommu_type vsmmu_type;
> > > + int (*vsmmu_init)(struct arm_vsmmu *vsmmu,
> > > + const struct iommu_user_data *user_data);
> >
> > It would be nice to avoid adding data members to the ops structure, if
>
> You mean the "vsmmu_size" and "vsmmu_type" right?
Yup.
> So you want them to be removed, by having two impl_ops:
> size_t get_vsmmu_size(enum iommu_viommu_type vsmmu_type);
> int (*vsmmu_init)(struct arm_vsmmu *vsmmu,
> const struct iommu_user_data *user_data);
>
> right?
Yes, please.
> > at all possible. The easiest thing would probably be to add a function
> > for getting the vsmmu size and then pushing the two checks against
> > 'vsmmu_type' down into the impl_ops callbacks so that:
> >
> > 1. If the type is IOMMU_VIOMMU_TYPE_ARM_SMMUV3, we don't bother with
> > the impl_ops at all in arm_vsmmu_init() and arm_smmu_get_viommu_size()
>
> Hmm, I was hoping for an implementation could support the default
> IOMMU_VIOMMU_TYPE_ARM_SMMUV3 while having its own viommu_ops or so.
> But I think your suggestion is fine since there is no such a use
> case at this moment :)
>
> > 2. Otherwise, we pass the type into the impl_ops and they can check it
> >
> > Of course, that can be a patch on top of the series as there's no point
> > respinning the whole just for this.
>
> Thanks for that! I can draft a patch to send later this week once
> the requirements are confirmed.
Thank you!
Will
