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authorChristoph Hellwig <hch@lst.de>2018-04-16 15:24:51 +0200
committerChristoph Hellwig <hch@lst.de>2018-05-19 08:46:12 +0200
commit782e6769c0df744e773dc2acff71c974b3bba4e9 (patch)
tree4b7f513da50a3bce1cca7a28949258642e9c8ab7 /include/asm-generic/dma-mapping.h
parentdma-mapping: simplify Kconfig dependencies (diff)
downloadlinux-dev-782e6769c0df744e773dc2acff71c974b3bba4e9.tar.xz
linux-dev-782e6769c0df744e773dc2acff71c974b3bba4e9.zip
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 <hch@lst.de> Tested-by: Alexey Brodkin <abrodkin@synopsys.com> Acked-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to '')
-rw-r--r--include/asm-generic/dma-mapping.h9
1 files changed, 9 insertions, 0 deletions
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 */