From owner-freebsd-arch@FreeBSD.ORG  Tue Sep 23 14:15:34 2003
Return-Path: <owner-freebsd-arch@FreeBSD.ORG>
Delivered-To: freebsd-arch@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 4587E16A4B3
	for <arch@freebsd.org>; Tue, 23 Sep 2003 14:15:34 -0700 (PDT)
Received: from harmony.village.org (rover.bsdimp.com [204.144.255.66])
	by mx1.FreeBSD.org (Postfix) with ESMTP id D881343FE0
	for <arch@freebsd.org>; Tue, 23 Sep 2003 14:15:32 -0700 (PDT)
	(envelope-from imp@bsdimp.com)
Received: from localhost (warner@rover2.village.org [10.0.0.1])
	by harmony.village.org (8.12.9p1/8.12.3) with ESMTP id h8NLFUGA067802;
	Tue, 23 Sep 2003 15:15:31 -0600 (MDT)
	(envelope-from imp@bsdimp.com)
Date: Tue, 23 Sep 2003 15:15:30 -0600 (MDT)
Message-Id: <20030923.151530.84357823.imp@bsdimp.com>
To: dfr@nlsystems.com
From: "M. Warner Losh" <imp@bsdimp.com>
In-Reply-To: <1064305850.68463.67.camel@herring.nlsystems.com>
References: <1064266269.68463.42.camel@herring.nlsystems.com>
	<1494190000.1064269463@aslan.btc.adaptec.com>
	<1064305850.68463.67.camel@herring.nlsystems.com>
X-Mailer: Mew version 2.2 on Emacs 21.3 / Mule 5.0 (SAKAKI)
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
cc: gibbs@scsiguy.com
cc: arch@freebsd.org
Subject: Re: kobj multiple inheritance
X-BeenThere: freebsd-arch@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Discussion related to FreeBSD architecture
	<freebsd-arch.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>,
	<mailto:freebsd-arch-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-arch>
List-Post: <mailto:freebsd-arch@freebsd.org>
List-Help: <mailto:freebsd-arch-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>,
	<mailto:freebsd-arch-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 23 Sep 2003 21:15:34 -0000

In message: <1064305850.68463.67.camel@herring.nlsystems.com>
            Doug Rabson <dfr@nlsystems.com> writes:
: Hmm. Some kind of SYSINIT-driven ivar index allocator, perhaps?

I've logn thought this is an excellent idea.  Have a 32 bit name
space.  16 allocated to an interface and 16 that are private to that
interface.  That should be plenty of bits, and the read/write ivar
routines would still be simple.  Hide it behind a macro, and it
doesn't matter the sizes.

You'd change:

	switch (which) {
	case PCI_IVAR_ETHADDR:
	...
	}

to

	if (IVAR_SELECTOR(which) != pci_ivar)
		return (EIO);	 /* or pass it on? */
	switch (IVAR_PRIVATE(which))
	{
	case PCI_IVAR_ETHADDR:
	...
	}

Which isn't burdonsome at all.  If you have more than 65,000
interfaces in the system, then you have bigger issues :-)

Warner