a73d5cc09f
The MIPS busdma sync operations currently are a big no-op on coherent memory. This isn't strictly correct behaviour as we need a SYNC in here to ensure that the writes have finished and are visible in main memory before the MMIO accesses occur. This will have to be addressed in a later commit. But, before that happens, let's at least do a flush here to make things more "correct". This is required for even remotely sensible behaviour on mips74k with write-through memory enabled.