On Mon, 25 Jan 2010 18:35:46 -0800 adharmap@xxxxxxxxxxxxxx wrote: > From: Abhijeet Dharmapurikar <adharmap@xxxxxxxxxxx> > > Tests have shown that there is a significant performance gain > when a driver uses mapping/unmapping functions without a barrier > multiple times and calls dsb() only after the last buffer. This > api adds support for barrierless dma operations on ARMv6 > and ARMv7. > > Signed-off-by: Abhijeet Dharmapurikar <adharmap@xxxxxxxxxxxxxx> > --- > > Please refer to the earlier post here http://lkml.org/lkml/2010/1/4/347. > These changes only are only for the arm v6 and v7 > architecture and introduce dma_map/unmap_single_nobarrier api. > The idea is to extend the cpu_cache_fns.dma_.*_range functions to accept > a third boolean argument that tells it whether to execute the barrier or > skip it. Note that this applies over Linux 2.6.33-rc5 and needs a few changes > to apply on the linux-next tree. > > > arch/arm/include/asm/cacheflush.h | 12 ++++---- > arch/arm/include/asm/dma-mapping.h | 57 ++++++++++++++++++++++++++++++++++-- > arch/arm/mm/cache-v6.S | 15 ++++++---- > arch/arm/mm/cache-v7.S | 19 +++++++++++- > arch/arm/mm/dma-mapping.c | 17 ++++++----- > drivers/staging/dream/pmem.c | 4 +- > 6 files changed, 97 insertions(+), 27 deletions(-) Along with the other comments, the patch is also missing updates to Documentation/DMA-API.txt ... --- ~Randy -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
