hlist_entry
*item = hlist_entry(list, struct drm_hash_item, head);
(ptr) ? hlist_entry(ptr, type, member) : NULL
p ? (tp = hlist_entry(p, typeof(*tp), field)): NULL; p = p->next)
for (; p ? (tp = hlist_entry(p, typeof(*tp), field)): NULL; p = p->next)