iommu: Introduce iommu_paging_domain_alloc_flags()

iommu: Introduce iommu_paging_domain_alloc_flags()

Currently drivers calls iommu_paging_domain_alloc(dev) to get an
UNMANAGED domain. This is not sufficient to support PASID with
UNMANAGED domain as some HW like AMD requires certain page table type
to support PASIDs.

Also the domain_alloc_paging op only passes device as param for domain
allocation. This is not sufficient for AMD driver to decide the right
page table.

Instead of extending ops->domain_alloc_paging() it was decided to
enhance ops->domain_alloc_user() so that caller can pass various
additional flags.

Hence add iommu_paging_domain_alloc_flags() API which takes flags as
parameter. Caller can pass additional parameter to indicate type of
domain required, etc. iommu_paging_domain_alloc_flags() internally calls
appropriate callback function to allocate a domain.

Signed-off-by: Jason Gunthorpe <jgg@ziepe.ca>
[Added description - Vasant]
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20241028093810.5901-3-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>