Plenty of designated smoking areas after security but not on most concourses. Most gates are not too far from main lobbies and smoking areas. Pretty much a smoke anywhere airport. Only no smoking area noted was in the immigration and customs queues. Smoking allowed in most bars and bars frequently distributed along the concourse.
Smoking is permitted in most areas of the terminal, though there are designated smoking areas.
No smoking in immigration queues. No smoking airport. Only smoking area I have found is on the train platform. Hard to get to and a long ways from gates. Also note that United's Red Carpet Club has gone non-smoking in this airport.