Re: [PATCH v3 15/15] iommu: Clean up bus_set_iommu()

[Robin Murphy]

On 2022-07-07 13:54, Matthew Rosato wrote:
> On 7/7/22 8:49 AM, Matthew Rosato wrote:
> > On 7/5/22 1:08 PM, Robin Murphy wrote:
> > > Clean up the remaining trivial bus_set_iommu() callsites along
> > > with the implementation. Now drivers only have to know and care
> > > about iommu_device instances, phew!
> > >
> > > Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
> > > ---
> > >
> > > v3: Also catch Intel's cheeky open-coded assignment
> >
> > ...
> >
> > > diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
> > > index c898bcbbce11..dd957145fb81 100644
> > > --- a/drivers/iommu/s390-iommu.c
> > > +++ b/drivers/iommu/s390-iommu.c
> > > @@ -385,9 +385,3 @@ static const struct iommu_ops s390_iommu_ops = {
> > >           .free        = s390_domain_free,
> > >       }
> > >   };
> > > -
> > > -static int __init s390_iommu_init(void)
> > > -{
> > > -    return bus_set_iommu(&pci_bus_type, &s390_iommu_ops);
> > > -}
> > > -subsys_initcall(s390_iommu_init);
> >
> > Previously s390_iommu_ops was only being set for pci_bus_type, but 
> > with this series it will now also be set for platform_bus_type.

Ah, indeed I hadn't got as far as fully appreciating that to_zpci_dev() 
isn't robust enough on its own. Thanks for the patch, I've pulled it in 
and will include it in v4. Do I take it that all else works OK with this 
fixed?

Cheers,
Robin.

> > To tolerate that, this series needs a change along the lines of:
>
> ...  Sorry, let's try that again without a mangled diff:
>
> From: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
> Date: Thu, 7 Jul 2022 08:45:44 -0400
> Subject: [PATCH] iommu/s390: fail probe for non-pci device
>
>
> s390-iommu only supports pci_bus_type today
>
>
> Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
> ---
>   drivers/iommu/s390-iommu.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
>
>
> diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
> index dd957145fb81..762f892b4ec3 100644
> --- a/drivers/iommu/s390-iommu.c
> +++ b/drivers/iommu/s390-iommu.c
> @@ -185,7 +185,12 @@ static void s390_iommu_detach_device(struct 
> iommu_domain *domain,
>
>
>   static struct iommu_device *s390_iommu_probe_device(struct device *dev)
>   {
> -       struct zpci_dev *zdev = to_zpci_dev(dev);
> +       struct zpci_dev *zdev;
> +
> +       if (!dev_is_pci(dev))
> +               return ERR_PTR(-ENODEV);
> +
> +       zdev = to_zpci_dev(dev);
>
>
>          return &zdev->iommu_dev;
>   }