From owner-cvs-src@FreeBSD.ORG Thu Sep 15 18:21:02 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 D210A16A41F; Thu, 15 Sep 2005 18:21:02 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: from mv.twc.weather.com (mv.twc.weather.com [65.212.71.225]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2A4B343D48; Thu, 15 Sep 2005 18:21:02 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: from [10.50.41.233] (Not Verified[10.50.41.233]) by mv.twc.weather.com with NetIQ MailMarshal (v6, 0, 3, 8) id ; Thu, 15 Sep 2005 14:36:42 -0400 From: John Baldwin To: src-committers@FreeBSD.org Date: Thu, 15 Sep 2005 13:41:41 -0400 User-Agent: KMail/1.8 References: <200509151709.j8FH9hkm099887@repoman.freebsd.org> In-Reply-To: <200509151709.j8FH9hkm099887@repoman.freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-6" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200509151341.42862.jhb@FreeBSD.org> Cc: cvs-src@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 18:21:03 -0000 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. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org