Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941998AbcJYWBG (ORCPT ); Tue, 25 Oct 2016 18:01:06 -0400 Received: from smtprelay4.synopsys.com ([198.182.47.9]:46902 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751741AbcJYWBF (ORCPT ); Tue, 25 Oct 2016 18:01:05 -0400 Subject: Re: [net-next PATCH 04/27] arch/arc: Add option to skip sync on DMA mapping To: Alexander Duyck , "netdev@vger.kernel.org" , "intel-wired-lan@lists.osuosl.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" References: <20161025153220.4815.61239.stgit@ahduyck-blue-test.jf.intel.com> <20161025153709.4815.82720.stgit@ahduyck-blue-test.jf.intel.com> CC: Vineet Gupta , "linux-snps-arc@lists.infradead.org" , "davem@davemloft.net" , "brouer@redhat.com" From: Vineet Gupta Message-ID: <64b46a7b-7ad4-5d09-5a0b-22dfaed8855e@synopsys.com> Date: Tue, 25 Oct 2016 15:00:55 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <20161025153709.4815.82720.stgit@ahduyck-blue-test.jf.intel.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.10.161.33] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1036 Lines: 33 On 10/25/2016 02:38 PM, Alexander Duyck wrote: > 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: Vineet Gupta > Cc: linux-snps-arc@lists.infradead.org > Signed-off-by: Alexander Duyck > --- > arch/arc/mm/dma.c | 5 ++++- Acked-by: Vineet Gupta > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c > index 20afc65..6303c34 100644 > --- a/arch/arc/mm/dma.c > +++ b/arch/arc/mm/dma.c > @@ -133,7 +133,10 @@ static dma_addr_t arc_dma_map_page(struct device *dev, struct page *page, > unsigned long attrs) > { > phys_addr_t paddr = page_to_phys(page) + offset; > - _dma_cache_sync(paddr, size, dir); > + > + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) > + _dma_cache_sync(paddr, size, dir); > + > return plat_phys_to_dma(dev, paddr); > } > > >