Re: [PATCH v3 00/10] Consolidate the probe_device path

[Jason Gunthorpe <jgg@nvidia.com>]

On Mon, Jun 05, 2023 at 09:59:38PM -0300, Jason Gunthorpe wrote:
> Now that the domain allocation path is less duplicated we can tackle the
> probe_device path. Details of this are spread across several functions,
> broadly move most of the code into __iommu_probe_device() and organize it
> more strictly in terms of paired do/undo functions.
> 
> Make the locking simpler by obtaining the group->mutex fewer times and
> avoiding adding a half-initialized device to an initialized
> group. Previously we would lock/unlock the group three times on these
> paths.
> 
> This locking change is the primary point of the series, creating the
> paired do/undo functions is a path to being able to organize the setup
> code under a single lock and still have a logical, not duplicated, error
> unwind.
> 
> The reorganizing is done with the idea that a following series will
> consolidate all of the different places calling arm_iommu_create_mapping()
> and iommu_setup_dma_ops() into the new consolidated probe path and get rid
> of probe_finalize.
> 
> This is on github: https://github.com/jgunthorpe/linux/commits/iommu_probe
> 
> v3:
>  - Rebase to Joerg's tree with both iommu_group_add/remove patchsets and
>    the iommu_err_unwind series
>  - Remove redundant lockdep_assert_held()
>  - No functional change from v2
> v2: https://lore.kernel.org/r/0-v2-3c3bb7aa6e48+1916b-iommu_probe_jgg@nvidia.com
>  - Rebase to v6.4-rc2
>  - Move the POWER cleanup to an independent -rc fix due to the iommu driver
>    being merged
>  - Update commit messages
>  - Rename iommu_init_driver() to iommu_init_device()
>  - Simplify __iommu_group_remove_device()
> v1: https://lore.kernel.org/r/0-v1-8aecc628b904+2f42-iommu_probe_jgg@nvidia.com
> 
> Cc: Nicolin Chen <nicolinc@nvidia.com>
> Cc: Lu Baolu <baolu.lu@linux.intel.com>
> Cc: Kevin Tian <kevin.tian@intel.com>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> 
> Jason Gunthorpe (10):
>   iommu: Have __iommu_probe_device() check for already probed devices
>   iommu: Use iommu_group_ref_get/put() for dev->iommu_group
>   iommu: Inline iommu_group_get_for_dev() into __iommu_probe_device()
>   iommu: Simplify the __iommu_group_remove_device() flow
>   iommu: Add iommu_init/deinit_device() paired functions
>   iommu: Move the iommu driver sysfs setup into
>     iommu_init/deinit_device()
>   iommu: Do not export iommu_device_link/unlink()
>   iommu: Always destroy the iommu_group during iommu_release_device()
>   iommu: Split iommu_group_add_device()
>   iommu: Avoid locking/unlocking for iommu_probe_device()

Joerg? I think we are good on this one now, it has been quite for two weeks

Thanks,
Jason