bcmpcie_decompose_tag
bcmpcie_decompose_tag(sc, ih.ih_tag, &bus, &dev, &fn);
void bcmpcie_decompose_tag(void *, pcitag_t, int *, int *, int *);
sc->sc_pc.pc_decompose_tag = bcmpcie_decompose_tag;
bcmpcie_decompose_tag(sc, tag, &bus, &dev, &fn);
bcmpcie_decompose_tag(sc, tag, &bus, &dev, &fn);