From 4bfa135abec99f4b35b5636f56a6db75ce3c64d7 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Wed, 14 Dec 2016 15:05:21 -0800 Subject: [PATCH] arch/xtensa: add option to skip DMA sync as a part of mapping 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 via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113555.76501.52536.stgit@ahduyck-blue-test.jf.intel.com Signed-off-by: Alexander Duyck Cc: Max Filippov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/xtensa/kernel/pci-dma.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c index 1e68806d6695..6a16decf278f 100644 --- a/arch/xtensa/kernel/pci-dma.c +++ b/arch/xtensa/kernel/pci-dma.c @@ -189,7 +189,9 @@ static dma_addr_t xtensa_map_page(struct device *dev, struct page *page, { dma_addr_t dma_handle = page_to_phys(page) + offset; - xtensa_sync_single_for_device(dev, dma_handle, size, dir); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + xtensa_sync_single_for_device(dev, dma_handle, size, dir); + return dma_handle; } @@ -197,7 +199,8 @@ static void xtensa_unmap_page(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction dir, unsigned long attrs) { - xtensa_sync_single_for_cpu(dev, dma_handle, size, dir); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + xtensa_sync_single_for_cpu(dev, dma_handle, size, dir); } static int xtensa_map_sg(struct device *dev, struct scatterlist *sg,