Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262226AbUCEFjz (ORCPT ); Fri, 5 Mar 2004 00:39:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262229AbUCEFjz (ORCPT ); Fri, 5 Mar 2004 00:39:55 -0500 Received: from zcars0m9.nortelnetworks.com ([47.129.242.157]:65174 "EHLO zcars0m9.nortelnetworks.com") by vger.kernel.org with ESMTP id S262226AbUCEFjx (ORCPT ); Fri, 5 Mar 2004 00:39:53 -0500 Message-ID: <404812A2.70207@nortelnetworks.com> Date: Fri, 05 Mar 2004 00:39:46 -0500 X-Sybari-Space: 00000000 00000000 00000000 00000000 From: Chris Friesen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.8) Gecko/20020204 X-Accept-Language: en-us MIME-Version: 1.0 To: Benjamin Herrenschmidt Cc: Linux Kernel list , Tom Rini Subject: Re: problem with cache flush routine for G5? References: <40479A50.9090605@nortelnetworks.com> <1078444268.5698.27.camel@gaston> <4047CBB3.9050608@nortelnetworks.com> <1078452637.5700.45.camel@gaston> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1451 Lines: 44 Benjamin Herrenschmidt wrote: > In fact, none of the cache flush code is > relying on supervisor mode, you don't need to add a syscall for > that, just copy the code you need in userland. That's useful information. > That's wrong. You should flush the cache over the range > where you need it flushed. Yeah, I know. I'm not sure why they want this. > Also, there are very few reasons > why one would want to flush the dcache, so it would be interesting > to know what you are really trying to do. I'll look into it further and see what I can find out. Assuming that I really did want to flush the whole cache, how would I go about doing that from userspace? Do it like the loop in arch/ppc/boot/common/util.S? How would this interact with virtual addresses? Would I need to mmap an appropriately sized area of kernel memory to get contiguous memory? The app is running as root, so permissions are not an issue. Thanks for your help, Chris -- Chris Friesen | MailStop: 043/33/F10 Nortel Networks | work: (613) 765-0557 3500 Carling Avenue | fax: (613) 765-2986 Nepean, ON K2H 8E9 Canada | email: cfriesen@nortelnetworks.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/