FUJITA Tomonori wrote: > On Fri, 12 Mar 2010 20:12:39 +0100 > Albert Herranz <albert_herr...@yahoo.es> wrote: > >> The current SWIOTLB code does not support NOT_COHERENT_CACHE platforms. >> This patch adds support for NOT_COHERENT_CACHE platforms to SWIOTLB by >> adding two platform specific functions swiotlb_dma_sync_page() and >> swiotlb_dma_sync() which can be used to explicitly manage cache coherency. >> >> On PowerPC these functions are mapped to their corresponding >> __dma_sync_page() and __dma_sync() functions. >> On other architectures using SWIOTLB these functions are optimized out. >> >> This will be used later to support SWIOTLB on the Nintendo Wii video game >> console. >> >> CC: linuxppc-dev@lists.ozlabs.org >> CC: linux-ker...@vger.kernel.org >> CC: x...@kernel.org >> CC: linux-i...@vger.kernel.org >> Signed-off-by: Albert Herranz <albert_herr...@yahoo.es> >> --- >> arch/ia64/include/asm/swiotlb.h | 10 ++++++++++ >> arch/powerpc/include/asm/swiotlb.h | 3 +++ >> arch/x86/include/asm/swiotlb.h | 10 ++++++++++ >> lib/swiotlb.c | 30 ++++++++++++++++++++++++------ >> 4 files changed, 47 insertions(+), 6 deletions(-) > > Why can't you use dma_sync_single_* instead of inventing new > swiotlb sync functions? >
At least on PowerPC, the DMA ops are per-device hooks. We attach the swiotlb DMA ops functions to those hooks when we are using swiotlb. So calling dma_sync_single_*() would end up calling swiotlb_sync_single_*() which is not what we want. Thanks, Albert _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
