From owner-cvs-all@FreeBSD.ORG Wed Apr 26 17:12:21 2006 Return-Path: X-Original-To: cvs-all@FreeBSD.org Delivered-To: cvs-all@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A019816A401; Wed, 26 Apr 2006 17:12:21 +0000 (UTC) (envelope-from jmg@hydrogen.funkthat.com) Received: from hydrogen.funkthat.com (gate.funkthat.com [69.17.45.168]) by mx1.FreeBSD.org (Postfix) with ESMTP id 33BDF43D48; Wed, 26 Apr 2006 17:12:21 +0000 (GMT) (envelope-from jmg@hydrogen.funkthat.com) Received: from hydrogen.funkthat.com (2fxx3klqxkn5f80z@localhost.funkthat.com [127.0.0.1]) by hydrogen.funkthat.com (8.13.4/8.13.3) with ESMTP id k3QHC4U5002214; Wed, 26 Apr 2006 10:12:04 -0700 (PDT) (envelope-from jmg@hydrogen.funkthat.com) Received: (from jmg@localhost) by hydrogen.funkthat.com (8.13.4/8.13.3/Submit) id k3QHBwBf002207; Wed, 26 Apr 2006 10:11:58 -0700 (PDT) (envelope-from jmg) Date: Wed, 26 Apr 2006 10:11:57 -0700 From: John-Mark Gurney To: "M. Warner Losh" Message-ID: <20060426171157.GE728@funkthat.com> References: <20060425223519.F65802@ns1.feral.com> <444F0923.8050508@samsco.org> <20060426.101245.90994186.imp@bsdimp.com> <20060426.102502.11595340.imp@bsdimp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060426.102502.11595340.imp@bsdimp.com> User-Agent: Mutt/1.4.2.1i X-Operating-System: FreeBSD 5.4-RELEASE-p6 i386 X-PGP-Fingerprint: B7 EC EF F8 AE ED A7 31 96 7A 22 B3 D8 56 36 F4 X-Files: The truth is out there X-URL: http://resnet.uoregon.edu/~gurney_j/ X-Resume: http://resnet.uoregon.edu/~gurney_j/resume.html Cc: scottl@samsco.org, src-committers@FreeBSD.org, bde@zeta.org.au, jhb@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org, mj@feral.com Subject: Re: cvs commit: src/sys/dev/bce if_bcereg.h X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: John-Mark Gurney List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Apr 2006 17:12:21 -0000 Warner Losh wrote this message on Wed, Apr 26, 2006 at 10:25 -0600: > In message: <20060426.101245.90994186.imp@bsdimp.com> > : bus_size_t is for differences between two bus_addr_t quantities, since > : it specifies the size of resources on a bus. It is also used for > : transfer sizes and the like. That's why I think it should be a 64-bit > : quantity: 64-bit - 64-bit = 64-bit. > > I should have added that if there's a substantial penalty for going to > 64-bits, then we should avoid it. My objections are based on the > resource allocation perspective, not the DMA segment size perspective. > It will be a while before video cards have > 4G window of resources > presented to the system. While an individual DMA transfer on the > PCI-E bus may not cross such a boundary, I bleieve that individual > resources can consume more than 4G. Our PCI code doesn't handle BARs > that are > 4G in size correctly, but it does handle BARs that are > mapped anywhere in a 64-bit address space. I have patches (in the sun4v tree) to the pcib code that has it properly support 64bit addresses... -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."