From: Alexander Duyck Date: Wed, 14 Dec 2016 23:04:41 +0000 (-0800) Subject: arch/c6x: add option to skip sync on DMA map and unmap X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=64c596b59c726514f548e15f13a87010efbff40d;p=linux-beck.git arch/c6x: add option to skip sync on DMA map and unmap This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it later via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113442.76501.7673.stgit@ahduyck-blue-test.jf.intel.com Signed-off-by: Alexander Duyck Acked-by: Mark Salter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/c6x/kernel/dma.c b/arch/c6x/kernel/dma.c index db4a6a301f5e..6752df32ef06 100644 --- a/arch/c6x/kernel/dma.c +++ b/arch/c6x/kernel/dma.c @@ -42,14 +42,17 @@ static dma_addr_t c6x_dma_map_page(struct device *dev, struct page *page, { dma_addr_t handle = virt_to_phys(page_address(page) + offset); - c6x_dma_sync(handle, size, dir); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + c6x_dma_sync(handle, size, dir); + return handle; } static void c6x_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size, enum dma_data_direction dir, unsigned long attrs) { - c6x_dma_sync(handle, size, dir); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + c6x_dma_sync(handle, size, dir); } static int c6x_dma_map_sg(struct device *dev, struct scatterlist *sglist, @@ -60,7 +63,8 @@ static int c6x_dma_map_sg(struct device *dev, struct scatterlist *sglist, for_each_sg(sglist, sg, nents, i) { sg->dma_address = sg_phys(sg); - c6x_dma_sync(sg->dma_address, sg->length, dir); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + c6x_dma_sync(sg->dma_address, sg->length, dir); } return nents; @@ -72,9 +76,11 @@ static void c6x_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, struct scatterlist *sg; int i; + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + return; + for_each_sg(sglist, sg, nents, i) c6x_dma_sync(sg_dma_address(sg), sg->length, dir); - } static void c6x_dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle,