From owner-cvs-all Wed Sep 29 8:41:40 1999 Delivered-To: cvs-all@freebsd.org Received: from eclogite.eps.nagoya-u.ac.jp (eclogite.eps.nagoya-u.ac.jp [133.6.124.145]) by hub.freebsd.org (Postfix) with ESMTP id A29F515890; Wed, 29 Sep 1999 08:38:29 -0700 (PDT) (envelope-from kato@ganko.eps.nagoya-u.ac.jp) Received: from localhost (gneiss.eps.nagoya-u.ac.jp [133.6.124.148]) by eclogite.eps.nagoya-u.ac.jp (8.9.3/3.7W) with ESMTP id AAA06210; Thu, 30 Sep 1999 00:38:08 +0900 (JST) To: bde@zeta.org.au Cc: nyan@FreeBSD.org, imp@village.org, winter@jurai.net, kato@FreeBSD.org, cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org, FreeBSD98-hackers@jp.freebsd.org Subject: Re: cvs commit: src/sys/conf files src/sys/i386/conf files.i386 From: KATO Takenori In-Reply-To: Your message of "Wed, 29 Sep 1999 03:06:50 +1000 (EST)" References: X-Mailer: Mew version 1.93 on Emacs 19.34 / Mule 2.3 (SUETSUMUHANA) X-PGP-Fingerprint: 03 72 85 36 62 46 23 03 52 B1 10 22 44 10 0D 9E Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <19990930003738A.kato@gneiss.eps.nagoya-u.ac.jp> Date: Thu, 30 Sep 1999 00:37:38 +0900 X-Dispatcher: imput version 980905(IM100) Lines: 31 Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk Bruce Evans wrote: > Doesn't this require changing all drivers that currently use the > bus space functions to be changed to initialise their sc->sc_bsh.base > instead of their sc->sc_bsh? This is uglier than casting. It would be hard work. But compilng LINT kernel may tell us missing changes. > 1) Only one bus type supported, and the tag for that is a compile-time > constant. Otherwise, there will be an extra branch in the bus space > routines for getting to the inirect case. This branch will cost > more than indirection on most machines. Of cource, your method has advantage to performance. But if we use your method (using bus_space_foo with zero offset) in a driver, I think that there isn't much meaing of usinge bus space. If performance loss is not negligible, separating such code into MD part and using inb/outb may solve the problem. If performance loss is negligible, using bus_space_foo with non-zero offset could not have performacne problem. -----------------------------------------------+--------------------------+ KATO Takenori | FreeBSD | Dept. Earth Planet. Sci, Nagoya Univ. | The power to serve! | Nagoya, 464-8602, Japan | http://www.FreeBSD.org/ | ++++ FreeBSD(98) 3.2: Rev. 01 available! |http://www.jp.FreeBSD.org/| ++++ FreeBSD(98) 2.2.8: Rev. 02 available! +==========================+ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message