539  * Calculate the P2PDMA mapping type and distance between two PCI devices.
542  * PCI_P2PDMA_MAP_BUS_ADDR and a distance of 0.
545  * PCI_P2PDMA_MAP_BUS_ADDR and a distance of 2 (one hop up to the bridge,
549  * return a distance of 4. This corresponds to the following PCI tree:
558  * The distance is 4 because we traverse from Device A to Downstream Port 0
570  * PCI_P2PDMA_MAP_THRU_HOST_BRIDGE with the distance set to the number of
670  * pci_p2pdma_distance_many - Determine the cumulative distance between
693 	int i, distance;  in pci_p2pdma_distance_many()  local
707 		map = calc_map_type_and_dist(provider, pci_client, &distance,  in pci_p2pdma_distance_many()
718 		total_dist += distance;  in pci_p2pdma_distance_many()
748  *	the specified list of clients and shortest distance
756  * distance away, one will be chosen at random.
765 	int distance;  in pci_p2pmem_find_many()  local
780 		distance = pci_p2pdma_distance_many(pdev, clients,  in pci_p2pmem_find_many()
782 		if (distance < 0 || distance > closest_distance)  in pci_p2pmem_find_many()
785 		if (distance == closest_distance && dev_cnt >= max_devs)  in pci_p2pmem_find_many()
788 		if (distance < closest_distance) {  in pci_p2pmem_find_many()
793 			closest_distance = distance;  in pci_p2pmem_find_many()