dma-mapping: move the remap helpers to a separate file
The dma remap code only makes sense for not cache coherent architectures
(or possibly the corner case of highmem CMA allocations) and currently
is only used by arm, arm64, csky and xtensa. Split it out into a
separate file with a separate Kconfig symbol, which gets the right
copyright notice given that this code was written by Laura Abbott
working for Code Aurora at that point.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index d29b736..239bfb1 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -11,6 +11,7 @@
select CLONE_BACKWARDS
select COMMON_CLK
select DMA_DIRECT_OPS
+ select DMA_REMAP if MMU
select GENERIC_ATOMIC64
select GENERIC_CLOCKEVENTS
select GENERIC_IRQ_SHOW