Pierce meat with a sharp knife in several places and press the garlic paste into the openings. Rub the meat with the remaining garlic mixture and olive oil. Place pork loin into oven, turning and basting with pan liquids. Cook until the pork is no longer pink in the center, about 1 hour. An instant-read thermometer inserted into the center should read 145 degrees F (63 degrees C). Remove roast to a platter.