The rear brakes are the same brakes as the rear brakes on the regular 3 (whether or not the S60 uses the same rears as the 3, I don't know).
The front brakes use the same calipers and rotor size (just drilled for 5x114.3 instead of Volvo's 5x108) as the Volvo S40 T5 AWD (ONLY the AWD variant, not the regular T5).