amin Herrenschmidt 1316474318 +1000 dma-mapping: Add get_required_mask if arch overrides default If an architecture sets ARCH_HAS_DMA_GET_REQUIRED_MASK and has settable dma_map_ops, the required mask may change by the ops implementation. For example, a system that always has an mmu inline may only require 32 bits while a swiotlb would desire bits to cover all of memory. Therefore add the field if the architecture does not use the generic definition of dma_get_required_mask. The first use will by by powerpc. Note that this does add some dependency on the order in which files are visible here. Signed-off-by: Milton Miller Signed-off-by: Nishanth Aravamudan Signed-off-by: Benjamin Herrenschmidt Acked-by: FUJITA Tomonori