From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: [mm PATCH v2 11/26] arch/m68k: Add option to skip DMA sync as a part of mapping Date: Wed, 02 Nov 2016 07:14:17 -0400 Message-ID: <20161102111415.79519.38511.stgit@ahduyck-blue-test.jf.intel.com> References: <20161102111031.79519.14741.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, linux-m68k@lists.linux-m68k.org, Geert Uytterhoeven , linux-kernel@vger.kernel.org To: linux-mm@kvack.org, akpm@linux-foundation.org Return-path: In-Reply-To: <20161102111031.79519.14741.stgit@ahduyck-blue-test.jf.intel.com> Sender: linux-kernel-owner@vger.kernel.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 later via a sync_for_cpu or sync_for_device call. Cc: Geert Uytterhoeven Cc: linux-m68k@lists.linux-m68k.org Signed-off-by: Alexander Duyck --- arch/m68k/kernel/dma.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/m68k/kernel/dma.c b/arch/m68k/kernel/dma.c index 8cf97cb..0707006 100644 --- a/arch/m68k/kernel/dma.c +++ b/arch/m68k/kernel/dma.c @@ -134,7 +134,9 @@ static dma_addr_t m68k_dma_map_page(struct device *dev, struct page *page, { dma_addr_t handle = page_to_phys(page) + offset; - dma_sync_single_for_device(dev, handle, size, dir); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_sync_single_for_device(dev, handle, size, dir); + return handle; } @@ -146,6 +148,10 @@ static int m68k_dma_map_sg(struct device *dev, struct scatterlist *sglist, for_each_sg(sglist, sg, nents, i) { sg->dma_address = sg_phys(sg); + + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; + dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir); }