config HAS_DMA bool depends on !NO_DMA default y config NEED_SG_DMA_LENGTH bool config NEED_DMA_MAP_STATE bool config ARCH_DMA_ADDR_T_64BIT def_bool 64BIT || PHYS_ADDR_T_64BIT config ARCH_HAS_DMA_COHERENCE_H bool config HAVE_GENERIC_DMA_COHERENT bool config ARCH_HAS_SETUP_DMA_OPS bool config ARCH_HAS_SYNC_DMA_FOR_DEVICE bool config ARCH_HAS_SYNC_DMA_FOR_CPU bool select NEED_DMA_MAP_STATE config ARCH_HAS_SYNC_DMA_FOR_CPU_ALL bool config ARCH_HAS_DMA_COHERENT_TO_PFN bool config ARCH_HAS_DMA_MMAP_PGPROT bool config DMA_NONCOHERENT_CACHE_SYNC bool config DMA_VIRT_OPS bool depends on HAS_DMA config SWIOTLB bool select NEED_DMA_MAP_STATE config DMA_REMAP depends on MMU bool config DMA_DIRECT_REMAP bool select DMA_REMAP config DMA_API_DEBUG bool "Enable debugging of DMA-API usage" select NEED_DMA_MAP_STATE help Enable this option to debug the use of the DMA API by device drivers. With this option you will be able to detect common bugs in device drivers like double-freeing of DMA mappings or freeing mappings that were never allocated. This also attempts to catch cases where a page owned by DMA is accessed by the cpu in a way that could cause data corruption. For example, this enables cow_user_page() to check that the source page is not undergoing DMA. This option causes a performance degradation. Use only if you want to debug device drivers and dma interactions. If unsure, say N. config DMA_API_DEBUG_SG bool "Debug DMA scatter-gather usage" default y depends on DMA_API_DEBUG help Perform extra checking that callers of dma_map_sg() have respected the appropriate segment length/boundary limits for the given device when preparing DMA scatterlists. This is particularly likely to have been overlooked in cases where the dma_map_sg() API is used for general bulk mapping of pages rather than preparing literal scatter-gather descriptors, where there is a risk of unexpected behaviour from DMA API implementations if the scatterlist is technically out-of-spec. If unsure, say N.