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From:   Krishna Reddy <vdumpa@nvidia.com>
To:     Robin Murphy <robin.murphy@arm.com>,
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Subject: RE: [PATCH 02/13] iommu: Move bus setup to IOMMU device registration
Thread-Topic: [PATCH 02/13] iommu: Move bus setup to IOMMU device registration
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Date:   Fri, 22 Apr 2022 18:37:08 +0000
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Good effort to isolate bus config from smmu drivers.
Reviewed-By: Krishna Reddy <vdumpa@nvidia.com>

I have an orthogonal question here.
Can the following code handle the case, where different buses have differen=
t type of SMMU instances(like one bus has SMMUv2 and another bus has SMMUv3=
)?
If it need to handle the above case, can the smmu device bus be matched wit=
h specific bus here and ops set only for that bus?=20


> +       for (int i =3D 0; i < ARRAY_SIZE(iommu_buses); i++) {
> +               struct bus_type *bus =3D iommu_buses[i];
> +               const struct iommu_ops *bus_ops =3D bus->iommu_ops;
> +               int err;
> +
> +               WARN_ON(bus_ops && bus_ops !=3D ops);
> +               bus->iommu_ops =3D ops;
> +               err =3D bus_iommu_probe(bus);
> +               if (err) {
> +                       bus_for_each_dev(bus, NULL, iommu,
> remove_iommu_group);
> +                       bus->iommu_ops =3D bus_ops;
> +                       return err;
> +               }
> +       }


-KR