From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw0-f197.google.com (mail-yw0-f197.google.com [209.85.161.197]) by kanga.kvack.org (Postfix) with ESMTP id E3EE66B02B7 for ; Wed, 2 Nov 2016 13:15:44 -0400 (EDT) Received: by mail-yw0-f197.google.com with SMTP id r204so34433528ywb.0 for ; Wed, 02 Nov 2016 10:15:44 -0700 (PDT) Received: from mga06.intel.com (mga06.intel.com. [134.134.136.31]) by mx.google.com with ESMTPS id hi7si3449821pac.149.2016.11.02.10.15.44 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 02 Nov 2016 10:15:44 -0700 (PDT) Subject: [mm PATCH v2 15/26] arch/nios2: Add option to skip DMA sync as a part of map and unmap From: Alexander Duyck Date: Wed, 02 Nov 2016 07:14:47 -0400 Message-ID: <20161102111445.79519.84229.stgit@ahduyck-blue-test.jf.intel.com> In-Reply-To: <20161102111031.79519.14741.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 Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, akpm@linux-foundation.org Cc: Ley Foon Tan , linux-kernel@vger.kernel.org, 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: Ley Foon Tan Signed-off-by: Alexander Duyck --- arch/nios2/mm/dma-mapping.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/arch/nios2/mm/dma-mapping.c b/arch/nios2/mm/dma-mapping.c index d800fad..f6a5dcf 100644 --- a/arch/nios2/mm/dma-mapping.c +++ b/arch/nios2/mm/dma-mapping.c @@ -98,13 +98,17 @@ static int nios2_dma_map_sg(struct device *dev, struct scatterlist *sg, int i; for_each_sg(sg, sg, nents, i) { - void *addr; + void *addr = sg_virt(sg); - addr = sg_virt(sg); - if (addr) { - __dma_sync_for_device(addr, sg->length, direction); - sg->dma_address = sg_phys(sg); - } + if (!addr) + continue; + + sg->dma_address = sg_phys(sg); + + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; + + __dma_sync_for_device(addr, sg->length, direction); } return nents; @@ -117,7 +121,9 @@ static dma_addr_t nios2_dma_map_page(struct device *dev, struct page *page, { void *addr = page_address(page) + offset; - __dma_sync_for_device(addr, size, direction); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + __dma_sync_for_device(addr, size, direction); + return page_to_phys(page) + offset; } @@ -125,7 +131,8 @@ static void nios2_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 void nios2_dma_unmap_sg(struct device *dev, struct scatterlist *sg, @@ -138,6 +145,9 @@ static void nios2_dma_unmap_sg(struct device *dev, struct scatterlist *sg, if (direction == DMA_TO_DEVICE) return; + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + return; + for_each_sg(sg, sg, nhwentries, i) { addr = sg_virt(sg); if (addr) -- 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