Anyone experience with integration of OpenCL within simulink models for xPC / Linux targets?

Recently i followed a seminar on OpenCL. This seems to be a quite powerfull framework to exploit processing power on FPGA's and have flexibility in the way it is synthesized. We use simulink to develop xPC and linux based realtime control systems. OpenCL would give an opportunity to offload specific high-performance filtering/processing needs. Has anyone tried this before? Can you share your experience with respect to integration of the tooling? Is there support from simulink to integrate OpenCL calculations or are S-function the only way?