Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933180AbcKBRQT (ORCPT ); Wed, 2 Nov 2016 13:16:19 -0400 Received: from mga09.intel.com ([134.134.136.24]:26478 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932766AbcKBRQQ (ORCPT ); Wed, 2 Nov 2016 13:16:16 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,583,1473145200"; d="scan'208";a="26680032" Subject: [mm PATCH v2 18/26] arch/powerpc: Add option to skip DMA sync as a part of mapping From: Alexander Duyck To: linux-mm@kvack.org, akpm@linux-foundation.org Cc: Benjamin Herrenschmidt , linux-kernel@vger.kernel.org, Paul Mackerras , Michael Ellerman , netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Date: Wed, 02 Nov 2016 07:15:18 -0400 Message-ID: <20161102111513.79519.65315.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> 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: 1373 Lines: 40 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: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Alexander Duyck --- arch/powerpc/kernel/dma.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c index e64a601..6877e3f 100644 --- a/arch/powerpc/kernel/dma.c +++ b/arch/powerpc/kernel/dma.c @@ -203,6 +203,10 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, for_each_sg(sgl, sg, nents, i) { sg->dma_address = sg_phys(sg) + get_dma_offset(dev); sg->dma_length = sg->length; + + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; + __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction); } @@ -235,7 +239,10 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev, unsigned long attrs) { BUG_ON(dir == DMA_NONE); - __dma_sync_page(page, offset, size, dir); + + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + __dma_sync_page(page, offset, size, dir); + return page_to_phys(page) + offset + get_dma_offset(dev); }