From owner-freebsd-net Mon Oct 1 13:28:58 2001 Delivered-To: freebsd-net@freebsd.org Received: from beppo.feral.com (beppo.feral.com [192.67.166.79]) by hub.freebsd.org (Postfix) with ESMTP id 06BA337B40A for ; Mon, 1 Oct 2001 13:28:52 -0700 (PDT) Received: from mailhost.feral.com (mjacob@mailhost.feral.com [192.67.166.1]) by beppo.feral.com (8.11.3/8.11.3) with ESMTP id f91KSjH85007; Mon, 1 Oct 2001 13:28:45 -0700 (PDT) (envelope-from mjacob@feral.com) Date: Mon, 1 Oct 2001 13:28:44 -0700 (PDT) From: Matthew Jacob X-Sender: mjacob@beppo Reply-To: mjacob@feral.com To: Julian Elischer , Garrett Wollman Cc: freebsd-net@freebsd.org Subject: Re: review of minor clarifying comments In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Yes- this may have been true for a long time - but quite a number of Unix variants don't require it, so I forgot :-).. For example, neither OpenBSD nor NetBSD seem to require it. It turns out that this is only stumbled on rarely- but if it's all the same to you, a comment would help a lot. -matt On Mon, 1 Oct 2001, Julian Elischer wrote: > Not only that but the ifnet structure must be the first part of the arpcom > struct so that arpcm, ifnet and softc often need to be the same.. I've > been gradually trying to remove this requirement over the last 10 years > but it's still there.. :-/ > > Comments can't hurt though.. > > > On Mon, 1 Oct 2001, Matthew Jacob wrote: > > > > > This bit me in the butt yet again about FreeBSD and some assumptions about how > > a NIC's softc is laid out- I don't really it stated elsewhere, so a couple > > source file comments seem in order.. Frankly, this kind of assumption is > > dangerous and unnecessary with methods, but at the very least it ought to be > > commented, no? > > > > -matt > > > > > > Index: net/if_var.h > > =================================================================== > > RCS file: /home/ncvs/src/sys/net/if_var.h,v > > retrieving revision 1.37 > > diff -u -r1.37 if_var.h > > --- net/if_var.h 2001/09/18 17:41:42 1.37 > > +++ net/if_var.h 2001/10/01 20:00:08 > > @@ -105,6 +105,11 @@ > > * > > * (Would like to call this struct ``if'', but C isn't PL/1.) > > */ > > + > > +/* > > + * NB: For FreeBSD, it is assumed that each NIC driver's softc starts with > > + * one of these structures, typically held within an arpcom structure. > > + */ > > struct ifnet { > > void *if_softc; /* pointer to driver state */ > > char *if_name; /* name, e.g. ``en'' or ``lo'' */ > > Index: dev/mii/mii.c > > =================================================================== > > RCS file: /home/ncvs/src/sys/dev/mii/mii.c,v > > retrieving revision 1.9 > > diff -u -r1.9 mii.c > > --- dev/mii/mii.c 2001/09/29 18:40:06 1.9 > > +++ dev/mii/mii.c 2001/10/01 20:00:09 > > @@ -167,6 +167,9 @@ > > struct mii_data *mii; > > > > mii = device_get_softc(dev); > > + /* > > + * Note that each NIC's softc must start with an ifnet structure. > > + */ > > mii->mii_ifp = device_get_softc(device_get_parent(dev)); > > v = device_get_ivars(dev); > > ifmedia_upd = v[0]; > > @@ -233,6 +236,9 @@ > > MIIBUS_LINKCHG(parent); > > > > mii = device_get_softc(dev); > > + /* > > + * Note that each NIC's softc must start with an ifnet structure. > > + */ > > ifp = device_get_softc(parent); > > > > if (mii->mii_media_status & IFM_AVALID) { > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > with "unsubscribe freebsd-net" in the body of the message > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message