dma-mapping: factor out dummy DMA ops
authorRobin Murphy <robin.murphy@arm.com>
Thu, 6 Dec 2018 21:14:44 +0000 (13:14 -0800)
committerChristoph Hellwig <hch@lst.de>
Thu, 13 Dec 2018 20:06:12 +0000 (21:06 +0100)
commit90ac706e98fcb24fb0b0a259558987f33cc2f0f6
tree3295030b39722a290ad409da73f28f223e9786f2
parent3731c3d4774e38b9d91c01943e1e6a243c1776be
dma-mapping: factor out dummy DMA ops

The dummy DMA ops are currently used by arm64 for any device which has
an invalid ACPI description and is thus barred from using DMA due to not
knowing whether is is cache-coherent or not. Factor these out into
general dma-mapping code so that they can be referenced from other
common code paths. In the process, we can prune all the optional
callbacks which just do the same thing as the default behaviour, and
fill in .map_resource for completeness.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[hch: moved to a separate source file]
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
arch/arm64/include/asm/dma-mapping.h
arch/arm64/mm/dma-mapping.c
include/linux/dma-mapping.h
kernel/dma/Makefile
kernel/dma/dummy.c [new file with mode: 0644]