[Linaro-mm-sig] [PATCH 2/8] ARM: dma-mapping: implement dma_map_single on top of dma_map_page
m.szyprowski at samsung.com
Mon Jun 20 15:15:43 UTC 2011
On Monday, June 20, 2011 4:39 PM Russell King - ARM Linux wrote:
> On Mon, Jun 20, 2011 at 09:50:07AM +0200, Marek Szyprowski wrote:
> > This patch consolidates dma_map_single and dma_map_page calls. This is
> > required to let dma-mapping framework on ARM architecture use common,
> > generic dma-mapping helpers.
> This breaks DMA API debugging, which requires that dma_map_page and
> dma_unmap_page are paired separately from dma_map_single and
Ok, right. This can be fixed by creating appropriate static inline functions
in dma-mapping.h and moving dma_debug_* calls there. These function will be
later removed by using dma_map_ops and include/asm-generic/dma-mapping-common.h
inlines, which do all the dma_debug_* calls correctly anyway.
> This also breaks dmabounce when used with a highmem-enabled system -
> dmabounce refuses the dma_map_page() API but allows the dma_map_single()
I really not sure how this change will break dma bounce code.
Does it mean that it is allowed to call dma_map_single() on kmapped HIGH_MEM
Samsung Poland R&D Center
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