This series was precipitated by Arnd removing CONFIG_VIRT_TO_BUS. The m68k WD33C93 still used virt_to_bus to convert virtual addresses to physical addresses suitable for the DMA engines (note m68k does not have an IOMMU and uses a direct mapping for DMA addresses). Arnd suggested to use dma_map_single() to set up dma mappings instead of open-coding much the same in every driver dma_setup() function. DMA setup on a3000 host adapters can be kept as-is (bounce buffers are used only where the input buffer isn't cache line aligned). Cache management is now taken care of by dma_map_single(). Note that I've restored bounce buffer allocation (dropped in v1) in order to make minimal changes to the core logic. On gvp11 and a2091 host adapters, only the lowest 16 MB of physical memory can be directy addressed by DMA, and bounce buffers from that space must be used (possibly allocated from chip RAM using the custom allocator) if buffers are located in the higher memory regions. No cache management is required for chip RAM bounce buffers. The m68k VME mvme147 driver has no DMA addressing or alignment restrictions and can be converted in the same way as the Amiga a3000 one, but will require conversion to a platform device driver first. Only compile tested so far, and hardware testing might be hard to do. Cheers, Michael
