Hi all, this series finishes off converting our dma mask model to split between device capabilities (dev->dma_mask and dev->coherent_dma_mask) and system limitations (dev->bus_dma_mask). We already accept larger than required masks in most dma_map_ops implementation, in case of x86 and implementations based on it since the dawn of time. Only one parisc and two sparc64 instances failed larger than required DMA masks, and this series fixes that up and updates the documentation that devices don't need to handle DMA mask fallbacks.