Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938840AbcJXSGG (ORCPT ); Mon, 24 Oct 2016 14:06:06 -0400 Received: from mga02.intel.com ([134.134.136.20]:55509 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S938692AbcJXSGB (ORCPT ); Mon, 24 Oct 2016 14:06:01 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,542,1473145200"; d="scan'208";a="1075007902" Subject: [net-next PATCH RFC 11/26] arch/metag: 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, James Hogan , linux-metag@vger.kernel.org, davem@davemloft.net Date: Mon, 24 Oct 2016 08:05:24 -0400 Message-ID: <20161024120524.16276.61479.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: 2027 Lines: 59 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); } }