hfi1_rcd_head
return hfi1_rcd_head(rcd) != tail;
packet->rhqoff = hfi1_rcd_head(rcd);
update_usrhead(packet->rcd, hfi1_rcd_head(packet->rcd), packet->updegr,
return hfi1_rcd_head(rcd) != get_rcvhdrtail(rcd);