From owner-svn-src-projects@FreeBSD.ORG Sun Jun 6 12:53:42 2010 Return-Path: Delivered-To: svn-src-projects@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 679161065676; Sun, 6 Jun 2010 12:53:42 +0000 (UTC) (envelope-from xcllnt@mac.com) Received: from asmtpout024.mac.com (asmtpout024.mac.com [17.148.16.99]) by mx1.freebsd.org (Postfix) with ESMTP id 462BC8FC1F; Sun, 6 Jun 2010 12:53:42 +0000 (UTC) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; charset=us-ascii Received: from macbook-pro.lan.xcllnt.net (mail.xcllnt.net [75.101.29.67]) by asmtp024.mac.com (Sun Java(tm) System Messaging Server 6.3-8.01 (built Dec 16 2008; 32bit)) with ESMTPSA id <0L3L00JC8FSVUB80@asmtp024.mac.com>; Sun, 06 Jun 2010 05:53:19 -0700 (PDT) X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 ipscore=0 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx engine=6.0.2-1004200000 definitions=main-1006060063 X-Proofpoint-Virus-Version: vendor=fsecure engine=1.12.8161:2.4.5,1.2.40,4.0.166 definitions=2010-06-06_01:2010-02-06, 2010-06-06, 2010-06-05 signatures=0 From: Marcel Moolenaar In-reply-to: Date: Sun, 06 Jun 2010 05:53:18 -0700 Message-id: References: <201006052041.o55KfMF6032155@svn.freebsd.org> <184A275D-B98A-4DBF-9F4D-22F27B9319DD@mac.com> <20100605.203348.651115405925906974.imp@bsdimp.com> <516EEDC6-069A-4780-84DF-BBFF43ABCDE5@samsco.org> To: Scott Long X-Mailer: Apple Mail (2.1078) Cc: svn-src-projects@FreeBSD.org, src-committers@FreeBSD.org, nwhitehorn@FreeBSD.org, "M. Warner Losh" Subject: Re: busdma [was: Re: svn commit: r208850 - projects/ppc64/sys/powerpc/include] X-BeenThere: svn-src-projects@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the src " projects" tree" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 06 Jun 2010 12:53:42 -0000 [about unifying busdma implementations] On Jun 6, 2010, at 1:06 AM, Scott Long wrote: >> Can you send me whatever you have or have done before so that I >> can leverage. >> > > I struggle with answering the question of whether to just reorg the interface definitions but leave the interface alone, or whether to rewrite the interface definitions in the context of having a new DMA api. *snip* I understand. All I can say is that when 90-95% of busdma is MI code and you only have a few MD functions, interface redesigns are a lot easier to manage and much less time-consuming to implement and test. I have an interest in busdma/mi, simply because it allows me add a feature to ia64 in a way that benefits all platforms and as such makes the work useful even if I have to abandon ia64 altogether. If busdma/mi ends your struggle and starts your work on busdma/ng, then I'm fine with that too. Then busdma/mi was still useful, just in a different way. Maybe busdma/ng cannot really happen without having busdma/mi first... -- Marcel Moolenaar xcllnt@mac.com