[PATCH] powerpc/iommu: Fix the missing iommu_group_put() during platform domain attach

[Jason Gunthorpe]

On Wed, Feb 14, 2024 at 11:53:20PM +1100, Michael Ellerman wrote:
> Venkat Rao Bagalkote <venkat88 at linux.vnet.ibm.com> writes:
> > Thanks for the patch. Applied this patch and verified and issue is fixed.
> >
> > This issue way originally reported in the below mail.
> >
> > https://marc.info/?l=linux-kernel&m=170737160630106&w=2
> 
> Please use lore for links, in this case:
> 
> https://lore.kernel.org/all/274e0d2b-b5cc-475e-94e6-8427e88e271d@linux.vnet.ibm.com/

Also if you are respinning you may prefer this

@@ -1285,14 +1285,15 @@ spapr_tce_platform_iommu_attach_dev(struct iommu_domain *platform_domain,
                                    struct device *dev)
 {
        struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
-       struct iommu_group *grp = iommu_group_get(dev);
        struct iommu_table_group *table_group;
+       struct iommu_group *grp;
        int ret = -EINVAL;
 
        /* At first attach the ownership is already set */
        if (!domain)
                return 0;
 
+       grp = iommu_group_get(dev);
        if (!grp)
                return -ENODEV;

Which is sort of why this happened in the first place :)

Jason