Re: [PATCH v6 02/12] iommu: Add pasid_bits field in struct dev_iommu

[Jason Gunthorpe]

On Wed, May 11, 2022 at 09:00:50AM +0100, Jean-Philippe Brucker wrote:

> > /**
> >  * struct iommu_device - IOMMU core representation of one IOMMU hardware
> >  *                       instance
> >  * @list: Used by the iommu-core to keep a list of registered iommus
> >  * @ops: iommu-ops for talking to this iommu
> >  * @dev: struct device for sysfs handling
> >  */
> > struct iommu_device {
> >         struct list_head list;
> >         const struct iommu_ops *ops;
> >         struct fwnode_handle *fwnode;
> >         struct device *dev;
> > };
> > 
> > I haven't checked ARM code yet, but it works for x86 as far as I can
> > see.
> 
> Arm also supports non-PCI PASID by reading a firmware property:
> 
>         device_property_read_u32(dev, "pasid-num-bits", &master->ssid_bits);
> 
> should be the only difference

That is not "ARM" that is generic DT/ACPI for platform devices and
should be handled by the core code in the same place it does PCI
discovery.

Jason