RDMA/restrack: Translate from ID to restrack object

Add new general helper to get restrack entry given by ID and their
respective type.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
diff --git a/include/rdma/restrack.h b/include/rdma/restrack.h
index 16e11b4..44ce32c 100644
--- a/include/rdma/restrack.h
+++ b/include/rdma/restrack.h
@@ -179,4 +179,7 @@
 int rdma_nl_put_driver_u64(struct sk_buff *msg, const char *name, u64 value);
 int rdma_nl_put_driver_u64_hex(struct sk_buff *msg, const char *name,
 			       u64 value);
+struct rdma_restrack_entry *rdma_restrack_get_byid(struct ib_device *dev,
+						   enum rdma_restrack_type type,
+						   u32 id);
 #endif /* _RDMA_RESTRACK_H_ */