From 782e6769c0df744e773dc2acff71c974b3bba4e9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 16 Apr 2018 15:24:51 +0200 Subject: dma-mapping: provide a generic dma-noncoherent implementation Add a new dma_map_ops implementation that uses dma-direct for the address mapping of streaming mappings, and which requires arch-specific implemenations of coherent allocate/free. Architectures have to provide flushing helpers to ownership trasnfers to the device and/or CPU, and can provide optional implementations of the coherent mmap functionality, and the cache_flush routines for non-coherent long term allocations. Signed-off-by: Christoph Hellwig Tested-by: Alexey Brodkin Acked-by: Vineet Gupta --- include/asm-generic/dma-mapping.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/asm-generic') diff --git a/include/asm-generic/dma-mapping.h b/include/asm-generic/dma-mapping.h index 880a292d792f..ad2868263867 100644 --- a/include/asm-generic/dma-mapping.h +++ b/include/asm-generic/dma-mapping.h @@ -4,7 +4,16 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) { + /* + * Use the non-coherent ops if available. If an architecture wants a + * more fine-grained selection of operations it will have to implement + * get_arch_dma_ops itself or use the per-device dma_ops. + */ +#ifdef CONFIG_DMA_NONCOHERENT_OPS + return &dma_noncoherent_ops; +#else return &dma_direct_ops; +#endif } #endif /* _ASM_GENERIC_DMA_MAPPING_H */ -- cgit v1.2.1