From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailout4.w1.samsung.com (mailout4.w1.samsung.com [210.118.77.14]) by ozlabs.org (Postfix) with ESMTP id 830A5B7198 for ; Fri, 23 Dec 2011 23:38:07 +1100 (EST) MIME-version: 1.0 Content-type: TEXT/PLAIN Received: from euspt2 ([210.118.77.14]) by mailout4.w1.samsung.com (Sun Java(tm) System Messaging Server 6.3-8.04 (built Jul 29 2009; 32bit)) with ESMTP id <0LWN005K4PANDJ40@mailout4.w1.samsung.com> for linuxppc-dev@lists.ozlabs.org; Fri, 23 Dec 2011 12:28:00 +0000 (GMT) Received: from linux.samsung.com ([106.116.38.10]) by spt2.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0LWN00K8RPAN36@spt2.w1.samsung.com> for linuxppc-dev@lists.ozlabs.org; Fri, 23 Dec 2011 12:27:59 +0000 (GMT) Date: Fri, 23 Dec 2011 13:27:32 +0100 From: Marek Szyprowski Subject: [PATCH 13/14] common: DMA-mapping: add WRITE_COMBINE attribute In-reply-to: <1324643253-3024-1-git-send-email-m.szyprowski@samsung.com> To: linux-kernel@vger.kernel.org Message-id: <1324643253-3024-14-git-send-email-m.szyprowski@samsung.com> References: <1324643253-3024-1-git-send-email-m.szyprowski@samsung.com> Cc: linux-mips@linux-mips.org, linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, linux-mm@kvack.org, sparclinux@vger.kernel.org, Marek Szyprowski , linux-arch@vger.kernel.org, Stephen Rothwell , Jonathan Corbet , x86@kernel.org, Arnd Bergmann , microblaze-uclinux@itee.uq.edu.au, linaro-mm-sig@lists.linaro.org, Andrzej Pietrasiewicz , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, discuss@x86-64.org, Kyungmin Park , linux-alpha@vger.kernel.org, Andrew Morton , linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , DMA_ATTR_WRITE_COMBINE specifies that writes to the mapping may be buffered to improve performance. It will be used by the replacement for ARM/ARV32 specific dma_alloc_writecombine() function. Signed-off-by: Marek Szyprowski Signed-off-by: Kyungmin Park --- Documentation/DMA-attributes.txt | 10 ++++++++++ include/linux/dma-attrs.h | 1 + 2 files changed, 11 insertions(+), 0 deletions(-) diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt index b768cc0..811a5d4 100644 --- a/Documentation/DMA-attributes.txt +++ b/Documentation/DMA-attributes.txt @@ -31,3 +31,13 @@ may be weakly ordered, that is that reads and writes may pass each other. Since it is optional for platforms to implement DMA_ATTR_WEAK_ORDERING, those that do not will simply ignore the attribute and exhibit default behavior. + +DMA_ATTR_WRITE_COMBINE +---------------------- + +DMA_ATTR_WRITE_COMBINE specifies that writes to the mapping may be +buffered to improve performance. + +Since it is optional for platforms to implement DMA_ATTR_WRITE_COMBINE, +those that do not will simply ignore the attribute and exhibit default +behavior. diff --git a/include/linux/dma-attrs.h b/include/linux/dma-attrs.h index 71ad34e..ada61e1 100644 --- a/include/linux/dma-attrs.h +++ b/include/linux/dma-attrs.h @@ -13,6 +13,7 @@ enum dma_attr { DMA_ATTR_WRITE_BARRIER, DMA_ATTR_WEAK_ORDERING, + DMA_ATTR_WRITE_COMBINE, DMA_ATTR_MAX, }; -- 1.7.1.569.g6f426