Date: Mon, 1 Oct 2001 13:28:44 -0700 (PDT) From: Matthew Jacob <mjacob@feral.com> To: Julian Elischer <julian@elischer.org>, Garrett Wollman <wollman@khavrinen.lcs.mit.edu> Cc: freebsd-net@freebsd.org Subject: Re: review of minor clarifying comments Message-ID: <Pine.BSF.4.21.0110011323270.99893-100000@beppo> In-Reply-To: <Pine.BSF.4.21.0110011410510.87441-100000@InterJet.elischer.org>
next in thread | previous in thread | raw e-mail | index | archive | help
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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.4.21.0110011323270.99893-100000>