From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761559AbXGKKBF (ORCPT ); Wed, 11 Jul 2007 06:01:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757640AbXGKKAy (ORCPT ); Wed, 11 Jul 2007 06:00:54 -0400 Received: from moutng.kundenserver.de ([212.227.126.179]:51949 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756690AbXGKKAx (ORCPT ); Wed, 11 Jul 2007 06:00:53 -0400 Message-ID: <4694AA52.6040207@anagramm.de> Date: Wed, 11 Jul 2007 12:00:50 +0200 From: Clemens Koller User-Agent: Thunderbird 2.0.0.4 (Windows/20070604) MIME-Version: 1.0 To: Manu Abraham CC: Nobin Mathew , "vraghavan3@mail.gatech.edu" , linux-kernel@vger.kernel.org Subject: Re: Reading a physical memory location References: <1184010444.469290cce48df@webmail.mail.gatech.edu> <8d6898730707091539y14cf5afbsed7ed769526da0a1@mail.gmail.com> <1184091142.4693cc06850f7@webmail.mail.gatech.edu> <1a297b360707101502t2670f0d7g5197b9c32ecb967c@mail.gmail.com> <8d6898730707102243t60861fdar147f052501c31958@mail.gmail.com> <1a297b360707110111u25a786c5m4857673e3e1b90a1@mail.gmail.com> <8d6898730707110114p3c02e24as8ca8359731fdc320@mail.gmail.com> <1a297b360707110150x56e8ad6cu64ab768e7d3ce6ed@mail.gmail.com> In-Reply-To: <1a297b360707110150x56e8ad6cu64ab768e7d3ce6ed@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Provags-ID: V01U2FsdGVkX1/pB/xxVBsJ2buvd8fMAQrjZJqcP5e0jowpMRv 9ZZ+5SwFI9bHrRAlFHQ0yM7HsIn45DynQqc8iKSUawDVeS8EIY Yr+ftYuPHt1FZkiGpaSaw== Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Manu Abraham schrieb: > On 7/11/07, Nobin Mathew wrote: >> See this in the documentation >> >> The returned virtual address is a current CPU mapping for the memory >> address given. It is only valid to use this function on addresses that >> have a kernel mapping >> >> This function does not handle bus mappings for DMA transfers. In >> almost all conceivable cases a device driver should not be using this >> function >> > > To get a better idea, look here > http://tldp.org/LDP/khg/HyperNews/get/devices/addrxlate.html Very nice! I have two more questions: 1. Is the document up to date? 2. Can anybody give an example how to "map" lots of pages (which got filled by i.e. a scatter gather DMA chain) from a driver (kernel space) to userspace? Thanks -- Clemens Koller __________________________________ R&D Imaging Devices Anagramm GmbH Rupert-Mayer-Straße 45/1 Linhof Werksgelände D-81379 München Tel.089-741518-50 Fax 089-741518-19 http://www.anagramm-technology.com