From owner-svn-src-head@FreeBSD.ORG Wed Jan 12 22:20:52 2011 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1DB52106566C; Wed, 12 Jan 2011 22:20:52 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id E3F438FC13; Wed, 12 Jan 2011 22:20:51 +0000 (UTC) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id 470ED46B38; Wed, 12 Jan 2011 17:20:51 -0500 (EST) Received: from jhbbsd.localnet (smtp.hudson-trading.com [209.249.190.9]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id 731F98A009; Wed, 12 Jan 2011 17:20:50 -0500 (EST) From: John Baldwin To: mdf@freebsd.org Date: Wed, 12 Jan 2011 17:06:28 -0500 User-Agent: KMail/1.13.5 (FreeBSD/7.4-CBSD-20110107; KDE/4.4.5; amd64; ; ) References: <201101122108.p0CL8o3Q012038@svn.freebsd.org> <201101121621.30371.jhb@freebsd.org> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201101121706.28930.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (bigwig.baldwin.cx); Wed, 12 Jan 2011 17:20:50 -0500 (EST) X-Virus-Scanned: clamav-milter 0.96.3 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-1.9 required=4.2 tests=BAYES_00 autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on bigwig.baldwin.cx Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r217330 - head/sys/x86/x86 X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 12 Jan 2011 22:20:52 -0000 On Wednesday, January 12, 2011 4:27:40 pm mdf@freebsd.org wrote: > On Wed, Jan 12, 2011 at 1:21 PM, John Baldwin wrote: > > On Wednesday, January 12, 2011 4:08:50 pm Matthew D Fleming wrote: > >> Author: mdf > >> Date: Wed Jan 12 21:08:49 2011 > >> New Revision: 217330 > >> URL: http://svn.freebsd.org/changeset/base/217330 > >> > >> Log: > >> Fix a brain fart. Since this file is shared between i386 and amd64, a > >> bus_size_t may be 32 or 64 bits. Change the bounce_zone alignment field > >> to explicitly be 32 bits, as I can't really imagine a DMA device that > >> needs anything close to 2GB alignment of data. > > > > Hmm, we do have devices with 4GB boundaries though. I think I'd prefer it if > > you instead if you did this: > > > > #if defined(amd64) || defined(PAE) > > #define SYSCTL_ADD_BUS_SIZE_T SYSCTL_ADD_UQUAD > > #else > > #define SYSCTL_ADD_BUS_SIZE_T SYSCTL_ADD_UINT > > #endif > > > > and then just used SYSCTL_ADD_BUS_SIZE_T() in the code so we could let the > > members in the bounce zone retain the same types passed to > > bus_dma_tag_create(). > > But would there be a device that can't start DMA except on a 4GB > boundary? I thought that's what this member was for. Probably not today, but I'd still prefer the types to be the real types. :) If this wasn't in x86 I'd imagine we'd be leaving the types as the real types and that other platforms that use bounce zones probably use the real types here as well. -- John Baldwin