414  * Calculate the P2PDMA mapping type and distance between two PCI devices.
417  * PCI_P2PDMA_MAP_BUS_ADDR and a distance of 0.
420  * PCI_P2PDMA_MAP_BUS_ADDR and a distance of 2 (one hop up to the bridge,
424  * return a distance of 4. This corresponds to the following PCI tree:
433  * The distance is 4 because we traverse from Device A to Downstream Port 0
445  * PCI_P2PDMA_MAP_THRU_HOST_BRIDGE with the distance set to the number of
545  * pci_p2pdma_distance_many - Determine the cumulative distance between
568 	int i, distance;  in pci_p2pdma_distance_many()  local
582 		map = calc_map_type_and_dist(provider, pci_client, &distance,  in pci_p2pdma_distance_many()
593 		total_dist += distance;  in pci_p2pdma_distance_many()
623  *	the specified list of clients and shortest distance (as determined
632  * distance away, one will be chosen at random.
641 	int distance;  in pci_p2pmem_find_many()  local
656 		distance = pci_p2pdma_distance_many(pdev, clients,  in pci_p2pmem_find_many()
658 		if (distance < 0 || distance > closest_distance)  in pci_p2pmem_find_many()
661 		if (distance == closest_distance && dev_cnt >= max_devs)  in pci_p2pmem_find_many()
664 		if (distance < closest_distance) {  in pci_p2pmem_find_many()
669 			closest_distance = distance;  in pci_p2pmem_find_many()