From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx125.postini.com [74.125.245.125]) by kanga.kvack.org (Postfix) with SMTP id B9B2E6B00F4 for ; Tue, 27 Mar 2012 09:43:30 -0400 (EDT) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: TEXT/PLAIN Received: from euspt1 ([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 <0M1J00KSHQ4FO160@mailout4.w1.samsung.com> for linux-mm@kvack.org; Tue, 27 Mar 2012 14:43:27 +0100 (BST) Received: from linux.samsung.com ([106.116.38.10]) by spt1.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0M1J008F2Q4CGS@spt1.w1.samsung.com> for linux-mm@kvack.org; Tue, 27 Mar 2012 14:43:25 +0100 (BST) Date: Tue, 27 Mar 2012 15:42:47 +0200 From: Marek Szyprowski Subject: [PATCHv2 13/14] common: DMA-mapping: add WRITE_COMBINE attribute In-reply-to: <1332855768-32583-1-git-send-email-m.szyprowski@samsung.com> Message-id: <1332855768-32583-14-git-send-email-m.szyprowski@samsung.com> References: <1332855768-32583-1-git-send-email-m.szyprowski@samsung.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: Benjamin Herrenschmidt , Thomas Gleixner , Andrew Morton , Arnd Bergmann , Stephen Rothwell , FUJITA Tomonori , microblaze-uclinux@itee.uq.edu.au, linux-arch@vger.kernel.org, x86@kernel.org, linux-sh@vger.kernel.org, linux-alpha@vger.kernel.org, sparclinux@vger.kernel.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mips@linux-mips.org, discuss@x86-64.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linaro-mm-sig@lists.linaro.org, Jonathan Corbet , Marek Szyprowski , Kyungmin Park , Andrzej Pietrasiewicz , Kevin Cernekee , Dezhong Diao , Richard Kuo , "David S. Miller" , Michal Simek , Guan Xuetao , Paul Mundt , Richard Henderson , Ivan Kokshaysky , Matt Turner , Tony Luck , Fenghua Yu 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 Acked-by: Kyungmin Park Reviewed-by: Arnd Bergmann --- 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org