--- zzzz-none-000/linux-4.4.60/arch/arm64/mm/dma-mapping.c	2017-04-08 07:53:53.000000000 +0000
+++ dragonfly-4020-701/linux-4.4.60/arch/arm64/mm/dma-mapping.c	2018-11-08 13:36:17.000000000 +0000
@@ -993,3 +993,4 @@
 	dev->archdata.dma_coherent = coherent;
 	__iommu_setup_dma_ops(dev, dma_base, size, iommu);
 }
+EXPORT_SYMBOL(arch_setup_dma_ops);