A data processing apparatus is provided, which includes: a plurality of processor cores; a shared processor cache, the shared processor cache being connected to each of the processor cores and to a main memory; a bus controller, the bus controller being connected to the shared processor cache and performing, in response to receiving a descriptor sent by one of the processor cores, a transfer of requested data indicated by the descriptor from the shared processor cache to an input/output (I/O) device; a bus unit, the bus unit being connected to the bus controller and transferring data to/from the I/O device; wherein the shared processor cache includes means for prefetching the requested data from the shared processor cache or main memory by performing a direct memory access in response to receiving a descriptor from the one of the processor cores.