common: DMA-mapping: add DMA_ATTR_NO_KERNEL_MAPPING attribute
authorMarek Szyprowski <m.szyprowski@samsung.com>
Wed, 16 May 2012 13:20:37 +0000 (15:20 +0200)
committerHiroshi Doyu <hdoyu@nvidia.com>
Fri, 7 Sep 2012 08:46:11 +0000 (11:46 +0300)
commitcd6a5b1bc9dc9790dda7d7054bbb88e0496f19ef
tree8ea73b05c4319fb8b42eab5ddead73f4a6bc9493
parentb1d956d891d30fd6cec9e9e46dd9cf40be8ef4aa
common: DMA-mapping: add DMA_ATTR_NO_KERNEL_MAPPING attribute

This patch adds DMA_ATTR_NO_KERNEL_MAPPING attribute which lets the
platform to avoid creating a kernel virtual mapping for the allocated
buffer. On some architectures creating such mapping is non-trivial task
and consumes very limited resources (like kernel virtual address space
or dma consistent address space). Buffers allocated with this attribute
can be only passed to user space by calling dma_mmap_attrs().

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Documentation/DMA-attributes.txt
include/linux/dma-attrs.h