AGP_I965_IFPADDR
hi = pci_conf_read(pc, tag, AGP_I965_IFPADDR+4);
lo = pci_conf_read(pc, tag, AGP_I965_IFPADDR);
pci_conf_write(pc, tag, AGP_I965_IFPADDR+4, hi);
pci_conf_write(pc, tag, AGP_I965_IFPADDR, lo);
AGP_I965_IFPADDR, 0);
AGP_I965_IFPADDR + 4, 0);