The actual opinion is quite short. https://www.supremecourt.gov/opinions/16pdf/15-777_7lho.pdf

It basically states that if a single component of a multi-component device infringes a patent, then calculations of damages based on profit can (but aren't required to) consider only the profit made on that component. While the ruling is in Samsung's favor, it seems unlikely to make much of a difference in the disposition of the case.