From: Rusty Russell Date: Fri, 9 Nov 2007 20:31:37 +1100 Subject: [PATCH] dma_map_sg_ring() helper No arch changes needed; it's easy to use dma_map_sg on one part at a time. Signed-off-by: Rusty Russell --- drivers/base/dma-mapping.c | 13 +++++++++++++ include/linux/dma-mapping.h | 4 ++++ 2 files changed, 17 insertions(+), 0 deletions(-) diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c index ca9186f..3d2f9eb 100644 --- a/drivers/base/dma-mapping.c +++ b/drivers/base/dma-mapping.c @@ -8,6 +8,7 @@ */ #include +#include /* * Managed DMA API @@ -162,6 +163,18 @@ void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr, } EXPORT_SYMBOL(dmam_free_noncoherent); +void dma_map_sg_ring(struct device *dev, struct sg_ring *sg, + enum dma_data_direction direction) +{ + struct sg_ring *i = sg; + + do { + BUG_ON(i->num > i->max); + i->num = dma_map_sg(dev, i->sg, i->num, direction); + } while ((i = sg_ring_next(i)) != sg); +} +EXPORT_SYMBOL(dma_map_sg_ring); + #ifdef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY static void dmam_coherent_decl_release(struct device *dev, void *res) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 101a2d4..06315b4 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -87,6 +87,10 @@ dma_mark_declared_memory_occupied(struct device *dev, } #endif +struct sg_ring; +extern void dma_map_sg_ring(struct device *dev, struct sg_ring *sg, + enum dma_data_direction direction); + /* * Managed DMA API */ -- 1.5.2.5