From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: [mm PATCH v3 09/23] arch/metag: Add option to skip DMA sync as a part of map and unmap Date: Thu, 10 Nov 2016 06:35:03 -0500 Message-ID: <20161110113503.76501.80809.stgit@ahduyck-blue-test.jf.intel.com> References: <20161110113027.76501.63030.stgit@ahduyck-blue-test.jf.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, James Hogan , linux-metag@vger.kernel.org, linux-kernel@vger.kernel.org To: linux-mm@kvack.org, akpm@linux-foundation.org Return-path: In-Reply-To: <20161110113027.76501.63030.stgit@ahduyck-blue-test.jf.intel.com> Sender: owner-linux-mm@kvack.org List-Id: netdev.vger.kernel.org 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. Cc: James Hogan Cc: linux-metag@vger.kernel.org Signed-off-by: Alexander Duyck --- arch/metag/kernel/dma.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/arch/metag/kernel/dma.c b/arch/metag/kernel/dma.c index 0db31e2..91968d9 100644 --- a/arch/metag/kernel/dma.c +++ b/arch/metag/kernel/dma.c @@ -484,8 +484,9 @@ static dma_addr_t metag_dma_map_page(struct device *dev, struct page *page, unsigned long offset, size_t size, enum dma_data_direction direction, unsigned long attrs) { - dma_sync_for_device((void *)(page_to_phys(page) + offset), size, - direction); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_sync_for_device((void *)(page_to_phys(page) + offset), + size, direction); return page_to_phys(page) + offset; } @@ -493,7 +494,8 @@ static void metag_dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size, enum dma_data_direction direction, unsigned long attrs) { - dma_sync_for_cpu(phys_to_virt(dma_address), size, direction); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_sync_for_cpu(phys_to_virt(dma_address), size, direction); } static int metag_dma_map_sg(struct device *dev, struct scatterlist *sglist, @@ -507,6 +509,10 @@ static int metag_dma_map_sg(struct device *dev, struct scatterlist *sglist, BUG_ON(!sg_page(sg)); sg->dma_address = sg_phys(sg); + + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; + dma_sync_for_device(sg_virt(sg), sg->length, direction); } @@ -525,6 +531,10 @@ static void metag_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, BUG_ON(!sg_page(sg)); sg->dma_address = sg_phys(sg); + + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; + dma_sync_for_cpu(sg_virt(sg), sg->length, direction); } } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org