From owner-cvs-src@FreeBSD.ORG Thu Sep 15 19:15:05 2005 Return-Path: X-Original-To: cvs-src@FreeBSD.org Delivered-To: cvs-src@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7A64A16A41F; Thu, 15 Sep 2005 19:15:05 +0000 (GMT) (envelope-from scottl@samsco.org) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.FreeBSD.org (Postfix) with ESMTP id C496D43D53; Thu, 15 Sep 2005 19:15:00 +0000 (GMT) (envelope-from scottl@samsco.org) Received: from [192.168.254.11] (junior.samsco.home [192.168.254.11]) (authenticated bits=0) by pooker.samsco.org (8.13.4/8.13.4) with ESMTP id j8FJExku001454; Thu, 15 Sep 2005 13:14:59 -0600 (MDT) (envelope-from scottl@samsco.org) Message-ID: <4329C835.6020104@samsco.org> Date: Thu, 15 Sep 2005 13:15:01 -0600 From: Scott Long User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.7.8) Gecko/20050615 X-Accept-Language: en-us, en MIME-Version: 1.0 To: John Baldwin References: <200509151709.j8FH9hkm099887@repoman.freebsd.org> <200509151341.42862.jhb@FreeBSD.org> In-Reply-To: <200509151341.42862.jhb@FreeBSD.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-2.8 required=3.8 tests=ALL_TRUSTED autolearn=failed version=3.0.2 X-Spam-Checker-Version: SpamAssassin 3.0.2 (2004-11-16) on pooker.samsco.org Cc: cvs-src@FreeBSD.org, src-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/alpha/alpha busdma_machdep.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Sep 2005 19:15:05 -0000 John Baldwin wrote: > On Thursday 15 September 2005 01:09 pm, John Baldwin wrote: > >>jhb 2005-09-15 17:09:42 UTC >> >> FreeBSD src repository >> >> Modified files: >> sys/alpha/alpha busdma_machdep.c >> Log: >> Add a memory barrier for PREWRITE operations to ensure all writes by the >> CPU have drained before further writes to kick off the operation. > > > Other architectures with relaxed memory ordering probably also need thus such > as ia64, powerpc, and perhaps amd64. sparc64 already has a barrier. BTW, it > seems that the bus_dma code could be somewhat simplified if there was a > sys/kern/subr_busdma.c that contained routines to implement bounce buffers > that could be used by the MD code since the MD code that does do bounce pages > tends to duplicate a lot of stuff between the different archs. > Indeed it does, and if you want to work on it, please feel free to send it to me for review. Scott