acpi_iort_map_pci_msi
int acpi_iort_map_pci_msi(u_int seg, u_int rid, u_int *xref, u_int *devid);
err = acpi_iort_map_pci_msi(sc->base.ecam, rid, &xref, &devid);
err = acpi_iort_map_pci_msi(sc->base.ecam, rid, &xref, &devid);