1941 J. Smiley 55 Up. This is usually added to another as ‘coffee up’ ‘waitress up’ or ‘bread up’ and designates the want or approach of a person or thing.
1950 ‘D. Divine’ xxi. 177 They heard her voice, ‘Chow up!’
1972 J. Porter xi. 138 Grub's up!.. Them as wants forks can fetch 'em!
1981 J. Wainwright 14 ‘Tea up.’ Wooley..carrying a steaming pot.