RTAS_FN_WRITE_PCI_CONFIG
write_pci_config = rtas_function_token(RTAS_FN_WRITE_PCI_CONFIG);
rval = rtas_call(rtas_function_token(RTAS_FN_WRITE_PCI_CONFIG), 3, 1, NULL,
rval = rtas_call(rtas_function_token(RTAS_FN_WRITE_PCI_CONFIG), 3, 1, NULL,