Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965478AbcJXSGz (ORCPT ); Mon, 24 Oct 2016 14:06:55 -0400 Received: from mga06.intel.com ([134.134.136.31]:16706 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965388AbcJXSGt (ORCPT ); Mon, 24 Oct 2016 14:06:49 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,542,1473145200"; d="scan'208";a="1049373258" Subject: [net-next PATCH RFC 20/26] arch/tile: Add option to skip DMA sync as a part of map and unmap From: Alexander Duyck To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: brouer@redhat.com, Chris Metcalf , davem@davemloft.net Date: Mon, 24 Oct 2016 08:06:12 -0400 Message-ID: <20161024120612.16276.63122.stgit@ahduyck-blue-test.jf.intel.com> In-Reply-To: <20161024115737.16276.71059.stgit@ahduyck-blue-test.jf.intel.com> References: <20161024115737.16276.71059.stgit@ahduyck-blue-test.jf.intel.com> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2026 Lines: 57 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: Chris Metcalf Signed-off-by: Alexander Duyck --- arch/tile/kernel/pci-dma.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/tile/kernel/pci-dma.c b/arch/tile/kernel/pci-dma.c index 09bb774..24e0f8c 100644 --- a/arch/tile/kernel/pci-dma.c +++ b/arch/tile/kernel/pci-dma.c @@ -213,10 +213,12 @@ static int tile_dma_map_sg(struct device *dev, struct scatterlist *sglist, for_each_sg(sglist, sg, nents, i) { sg->dma_address = sg_phys(sg); - __dma_prep_pa_range(sg->dma_address, sg->length, direction); #ifdef CONFIG_NEED_SG_DMA_LENGTH sg->dma_length = sg->length; #endif + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; + __dma_prep_pa_range(sg->dma_address, sg->length, direction); } return nents; @@ -232,6 +234,8 @@ static void tile_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, BUG_ON(!valid_dma_direction(direction)); for_each_sg(sglist, sg, nents, i) { sg->dma_address = sg_phys(sg); + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; __dma_complete_pa_range(sg->dma_address, sg->length, direction); } @@ -245,7 +249,8 @@ static dma_addr_t tile_dma_map_page(struct device *dev, struct page *page, BUG_ON(!valid_dma_direction(direction)); BUG_ON(offset + size > PAGE_SIZE); - __dma_prep_page(page, offset, size, direction); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + __dma_prep_page(page, offset, size, direction); return page_to_pa(page) + offset; } @@ -256,6 +261,9 @@ static void tile_dma_unmap_page(struct device *dev, dma_addr_t dma_address, { BUG_ON(!valid_dma_direction(direction)); + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + return; + __dma_complete_page(pfn_to_page(PFN_DOWN(dma_address)), dma_address & (PAGE_SIZE - 1), size, direction); }