OHCI1394_AT_DATA_Q0_srcBusID_MASK
return !!((data[0] & OHCI1394_AT_DATA_Q0_srcBusID_MASK) >> OHCI1394_AT_DATA_Q0_srcBusID_SHIFT);
data[0] &= cpu_to_le32(~OHCI1394_AT_DATA_Q0_srcBusID_MASK);
data[0] |= cpu_to_le32((src_bus_id << OHCI1394_AT_DATA_Q0_srcBusID_SHIFT) & OHCI1394_AT_DATA_Q0_srcBusID_MASK);