#ifndef _LINUX_DMA_MAPPING_H#define _LINUX_DMA_MAPPING_H#ifdef CONFIG_HAS_DMA# error Virtio userspace code does not support CONFIG_HAS_DMA#endif#define PCI_DMA_BUS_IS_PHYS 1enumdma_data_direction{DMA_BIDIRECTIONAL=0,DMA_TO_DEVICE=1,DMA_FROM_DEVICE=2,DMA_NONE=3,};#endif