iommu/vt-d: Refactor device_to_iommu() helper
It is refactored in two ways:
- Make it global so that it could be used in other files.
- Make bus/devfn optional so that callers could ignore these two returned
values when they only want to get the coresponding iommu pointer.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20200724014925.15523-9-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
3 files changed