dma-direct: provide generic support for uncached kernel segments
A few architectures support uncached kernel segments. In that case we get
an uncached mapping for a given physica address by using an offset in the
uncached segement. Implement support for this scheme in the generic
dma-direct code instead of duplicating it in arch hooks.
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/include/linux/dma-noncoherent.h b/include/linux/dma-noncoherent.h
index 9741767..7e0126a 100644
--- a/include/linux/dma-noncoherent.h
+++ b/include/linux/dma-noncoherent.h
@@ -80,4 +80,7 @@ static inline void arch_dma_prep_coherent(struct page *page, size_t size)
}
#endif /* CONFIG_ARCH_HAS_DMA_PREP_COHERENT */
+void *uncached_kernel_address(void *addr);
+void *cached_kernel_address(void *addr);
+
#endif /* _LINUX_DMA_NONCOHERENT_H */