Probably just the wifi TSF: https://en.wikipedia.org/wiki/Timing_Synchronization_Functio...
Notably used by the Wii U: https://patchwork.kernel.org/patch/5865651/
Notably used by the Wii U: https://patchwork.kernel.org/patch/5865651/
[0] http://web.cse.ohio-state.edu/~lai/788-Au03/2-scalibility.pd...
Meh. Still cool, but a far cry from the sub-MICROsecond accuracy the page suggest, which would indeed be quite revolutionary.