It's pay parking in most areas of Dublin on Sundays. If you are driving from Kerry, maybe parking in the Luas park and ride at Red Cow will take alot of the hassle out of it. Parking is €4 for the whole day, but your Luas ticket will be €3.80 for the return journey per adult.
Not southside but I always think a good place to park is at the Tesco on the Finglas Road not far from the M50, then just jump on a bus into Drumcondra. Bus takes 10 minutes and if it gets stuck at Harts Corner you can just walk the rest of the way to Croke Park.