+/**
+ * Device level DMA map function.
+ * After a successful call, the memory segment will be mapped to the
+ * given device.
+ *
+ * @param dev
+ * Device pointer.
+ * @param addr
+ * Virtual address to map.
+ * @param iova
+ * IOVA address to map.
+ * @param len
+ * Length of the memory segment being mapped.
+ *
+ * @return
+ * 0 if mapping was successful.
+ * Negative value and rte_errno is set otherwise.
+ */
+typedef int (*rte_dev_dma_map_t)(struct rte_device *dev, void *addr,
+ uint64_t iova, size_t len);
+
+/**
+ * Device level DMA unmap function.
+ * After a successful call, the memory segment will no longer be
+ * accessible by the given device.
+ *
+ * @param dev
+ * Device pointer.
+ * @param addr
+ * Virtual address to unmap.
+ * @param iova
+ * IOVA address to unmap.
+ * @param len
+ * Length of the memory segment being mapped.
+ *
+ * @return
+ * 0 if un-mapping was successful.
+ * Negative value and rte_errno is set otherwise.
+ */
+typedef int (*rte_dev_dma_unmap_t)(struct rte_device *dev, void *addr,
+ uint64_t iova, size_t len);
+
+/**
+ * Implement a specific hot-unplug handler, which is responsible for
+ * handle the failure when device be hot-unplugged. When the event of
+ * hot-unplug be detected, it could call this function to handle
+ * the hot-unplug failure and avoid app crash.
+ * @param dev
+ * Pointer of the device structure.
+ *
+ * @return
+ * 0 on success.
+ * !0 on error.
+ */
+typedef int (*rte_bus_hot_unplug_handler_t)(struct rte_device *dev);
+
+/**
+ * Implement a specific sigbus handler, which is responsible for handling
+ * the sigbus error which is either original memory error, or specific memory
+ * error that caused of device be hot-unplugged. When sigbus error be captured,
+ * it could call this function to handle sigbus error.
+ * @param failure_addr
+ * Pointer of the fault address of the sigbus error.
+ *
+ * @return
+ * 0 for success handle the sigbus for hot-unplug.
+ * 1 for not process it, because it is a generic sigbus error.
+ * -1 for failed to handle the sigbus for hot-unplug.
+ */
+typedef int (*rte_bus_sigbus_handler_t)(const void *failure_addr);
+
+/**
+ * Bus scan policies
+ */
+enum rte_bus_scan_mode {
+ RTE_BUS_SCAN_UNDEFINED,
+ RTE_BUS_SCAN_WHITELIST,
+ RTE_BUS_SCAN_BLACKLIST,
+};
+
+/**
+ * A structure used to configure bus operations.
+ */
+struct rte_bus_conf {
+ enum rte_bus_scan_mode scan_mode; /**< Scan policy. */
+};
+
+
+/**
+ * Get common iommu class of the all the devices on the bus. The bus may
+ * check that those devices are attached to iommu driver.
+ * If no devices are attached to the bus. The bus may return with don't care
+ * (_DC) value.
+ * Otherwise, The bus will return appropriate _pa or _va iova mode.
+ *
+ * @return
+ * enum rte_iova_mode value.
+ */
+typedef enum rte_iova_mode (*rte_bus_get_iommu_class_t)(void);
+
+