sid_bus
sbus = sid_bus(sid);
bus = sid_bus(sid);
ih.tag = pci_make_tag(NULL, sid_bus(devid), sid_dev(devid), sid_fun(devid));
sid_bus(sid), sid_dev(sid), sid_fun(sid));
ctx = &iommu->ctx[sid_bus(dd->sid)][sid_devfn(dd->sid)];
sid_bus(dd->sid),