drm_vma_offset_lock_lookup — Lock lookup for extended private use
| void drm_vma_offset_lock_lookup ( | struct drm_vma_offset_manager * mgr ); | 
   Lock VMA manager for extended lookups. Only *_locked VMA function calls
   are allowed while holding this lock. All other contexts are blocked from VMA
   until the lock is released via drm_vma_offset_unlock_lookup.
   
   Use this if you need to take a reference to the objects returned by
   drm_vma_offset_lookup_locked before releasing this lock again.
   
This lock must not be used for anything else than extended lookups. You must not call any other VMA helpers while holding this lock.