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To:     Robin Murphy <robin.murphy@arm.com>,
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Subject: RE: [PATCH v3 04/15] iommu: Move bus setup to IOMMU device
 registration
Thread-Topic: [PATCH v3 04/15] iommu: Move bus setup to IOMMU device
 registration
Thread-Index: AQHYkJHwF7q1lwdLwUOXyHWeZ9Wy4K1ydjbA
Date:   Thu, 7 Jul 2022 06:51:17 +0000
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> From: Robin Murphy <robin.murphy@arm.com>
> Sent: Wednesday, July 6, 2022 1:08 AM
>=20
> @@ -202,12 +210,32 @@ int iommu_device_register(struct iommu_device
> *iommu,
>  	spin_lock(&iommu_device_lock);
>  	list_add_tail(&iommu->list, &iommu_device_list);
>  	spin_unlock(&iommu_device_lock);
> +
> +	for (int i =3D 0; i < ARRAY_SIZE(iommu_buses); i++) {
> +		struct bus_type *bus =3D iommu_buses[i];
> +		int err;
> +
> +		if (bus->iommu_ops && bus->iommu_ops !=3D ops) {
> +			err =3D -EBUSY;
> +		} else {
> +			bus->iommu_ops =3D ops;
> +			err =3D bus_iommu_probe(bus);
> +		}
> +		if (err) {
> +			iommu_device_unregister(iommu);
> +			return err;
> +		}
> +	}
> +

Probably move above into a new function bus_iommu_probe_all():

	/* probe all buses for devices associated with this iommu */
	err =3D bus_iommu_probe_all();
	if (err) {
		iommu_device_unregister(iommu);
		return err;
	}

Just  my personal preference on leaving logic in iommu_device_register()
more relevant to the iommu instance itself.

Apart from that:

Reviewed-by: Kevin Tian <kevin.tian@intel.com>