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Message-ID: <4c25e3ad-0eb6-5c41-48b2-7c10e745bd5d@linux.ibm.com>
Date:   Thu, 7 Jul 2022 08:49:54 -0400
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Subject: Re: [PATCH v3 15/15] iommu: Clean up bus_set_iommu()
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To:     Robin Murphy <robin.murphy@arm.com>, joro@8bytes.org
Cc:     will@kernel.org, iommu@lists.linux.dev,
        linux-arm-kernel@lists.infradead.org, baolu.lu@linux.intel.com,
        suravee.suthikulpanit@amd.com, vasant.hegde@amd.com,
        gerald.schaefer@linux.ibm.com, schnelle@linux.ibm.com,
        linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org
References: <cover.1657034827.git.robin.murphy@arm.com>
 <dc44a2269276e1d0fa6715d4530a51df4e7b781c.1657034828.git.robin.murphy@arm.com>
From:   Matthew Rosato <mjrosato@linux.ibm.com>
In-Reply-To: <dc44a2269276e1d0fa6715d4530a51df4e7b781c.1657034828.git.robin.murphy@arm.com>
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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@arm.com>
> ---
> 
> 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.

To tolerate that, this series needs a change along the lines of:


From: Matthew Rosato <mjrosato@linux.ibm.com> 

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@linux.ibm.com> 

--- 

  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; 

  }  return &zdev->iommu_dev; 

  }