From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx119.postini.com [74.125.245.119]) by kanga.kvack.org (Postfix) with SMTP id D04126B004D for ; Tue, 10 Apr 2012 09:17:30 -0400 (EDT) From: Arnd Bergmann Subject: Re: [PATCHv8 07/10] ARM: dma-mapping: move all dma bounce code to separate dma ops structure Date: Tue, 10 Apr 2012 13:17:08 +0000 References: <1334055852-19500-1-git-send-email-m.szyprowski@samsung.com> <201204101224.24959.arnd@arndb.de> <002801cd1718$b556a1e0$2003e5a0$%szyprowski@samsung.com> In-Reply-To: <002801cd1718$b556a1e0$2003e5a0$%szyprowski@samsung.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201204101317.08765.arnd@arndb.de> Sender: owner-linux-mm@kvack.org List-ID: To: Marek Szyprowski Cc: linux-arm-kernel@lists.infradead.org, linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, iommu@lists.linux-foundation.org, 'Kyungmin Park' , 'Joerg Roedel' , 'Russell King - ARM Linux' , 'Chunsang Jeong' , 'Krishna Reddy' , 'KyongHo Cho' , Andrzej Pietrasiewicz , 'Benjamin Herrenschmidt' , 'Konrad Rzeszutek Wilk' , 'Hiroshi Doyu' , 'Subash Patel' On Tuesday 10 April 2012, Marek Szyprowski wrote: > Before patch no 6, there were custom methods for all scatter/gather > related operations. They iterated over the whole scatter list and called > cache related operations directly (which in turn checked if we use dma > bounce code or not and called respective version). Patch no 6 changed > them not to use such shortcut for direct calling cache related operations. > > Instead it provides similar loop over scatter list and calls methods > from the current device's dma_map_ops structure. This way, after patch no > 7 these functions call simple dma_map_page() method for all standard > devices and dma bounce aware version for devices registered for dma > bouncing (with use different dma_map_ops). Ok, thanks for the explanation. > I can provide a separate set of scatter/gather list related functions for > the linear dma mapping implementation and dma bouncing implementation > if you think that the current approach is too complicated or > over-engineered. It's probably not needed, though I have not looked at the big picture with all the patches applied. which I should do at some point. Arnd -- 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