Date: Tue, 30 Sep 2003 14:23:02 -0400 (EDT) From: John Baldwin <jhb@FreeBSD.org> To: Brooks Davis <brooks@one-eyed-alien.net> Cc: net@freebsd.org Subject: Re: adding if_dev member to struct ifnet Message-ID: <XFMail.20030930142302.jhb@FreeBSD.org> In-Reply-To: <20030930174815.GC31908@Odin.AC.HMC.Edu>
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On 30-Sep-2003 Brooks Davis wrote: > On Tue, Sep 30, 2003 at 01:14:39PM -0400, John Baldwin wrote: >> >> Fair enough. I think that Brooks planned to use a NULL device_t for >> interfaces w/o a backing new-bus device. However, that means you >> still need if_name for all the non-newbus devices, so this seems >> somewhat pointless if if_name is the only reason. Another counterpoint >> is that the new-bus namespace and the netif namespace aren't the same >> anyway and that seemed to be the point of this linkage. The >> dev_t <> softc <> device_t linkages aren't about unifying namespaces. > > The idea here is that virtually all uses of if_name/if_unit that aren't > just there for the users benefit are actually references to the > underlying driver not name of the interface. Currently they are the > same (i.e. ifname is nearly always device_get_name(dev) or a bug prone > manual version there of), but I would like to separate them so we can > rename interfaces. > > Since device_t is as close to a repository of driver/instance > information as we've got, I though using it would be a reasonable way > to go. As a side benefit, most drivers have a copy of it in their softc > already so you'd have a standard place to put it. > > I suppose a usable alternative would be to revive if_name and if_unit > as something like if_drvname and if_drvunit. Are these uses all within the driver itself? If so, then just giving ifnet a void * that is private to the driver would allow ifnet devices hung off of new-bus devices to cache their device_t w/o requiring the rest of the kernel to know what that private variable is. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/
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