[net-next PATCH 08/27] arch/c6x: Add option to skip sync on DMA map and unmap
From: Alexander Duyck <hidden>
Date: 2016-10-25 21:44:06
Also in:
intel-wired-lan, linux-mm, lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
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. Cc: Mark Salter <redacted> Cc: Aurelien Jacquiot <redacted> Signed-off-by: Alexander Duyck <redacted> --- arch/c6x/kernel/dma.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/arch/c6x/kernel/dma.c b/arch/c6x/kernel/dma.c
index db4a6a3..6752df3 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, --
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