Re: [PATCH v3 09/10] iommu/amd: Reorder attach device code

[Jason Gunthorpe <jgg@ziepe.ca>]

On Wed, Oct 16, 2024 at 05:35:00AM +0000, Vasant Hegde wrote:
> Ideally in attach device path, it should take dev_data lock before
> making changes to device data including IOPF enablement. So far dev_data
> was using spinlock and it was hitting lock order issue when it tries to
> enable IOPF. Hence Commit 526606b0a199 ("iommu/amd: Fix Invalid wait
> context issue") moved IOPF enablement outside dev_data->lock.
> 
> Previous patch converted dev_data lock to mutex. Now its safe to call
> amd_iommu_iopf_add_device() with dev_data->mutex. Hence move back PCI
> device capability enablement (ATS, PRI, PASID) and IOPF enablement code
> inside the lock. Also in attach_device(), update 'dev_data->domain' at
> the end so that error handling becomes simple.
> 
> Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
> ---
>  drivers/iommu/amd/iommu.c | 65 +++++++++++++++++----------------------
>  1 file changed, 29 insertions(+), 36 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason