Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965338AbcJXSGi (ORCPT ); Mon, 24 Oct 2016 14:06:38 -0400 Received: from mga11.intel.com ([192.55.52.93]:16652 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965234AbcJXSGd (ORCPT ); Mon, 24 Oct 2016 14:06:33 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,542,1473145200"; d="scan'208";a="893420373" Subject: [net-next PATCH RFC 17/26] arch/powerpc: Add option to skip DMA sync as a part of mapping From: Alexander Duyck To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , brouer@redhat.com, linuxppc-dev@lists.ozlabs.org, davem@davemloft.net Date: Mon, 24 Oct 2016 08:05:56 -0400 Message-ID: <20161024120556.16276.90940.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: 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); }