On 30-Sep-2003 Poul-Henning Kamp wrote: > In message <[EMAIL PROTECTED]>, John Baldwin writes: > >>>>Yes, if it helps to remove if_name/if_unit, it is a thing to do. Moreover it >>>>sounds a good idea to have the if_dev field into the ifnet structure. >>> >>> Somebody please explain how this would work for non-hardware >>> interfaces like if_loop, if_tun, if_tap etc ? >>> >>> device_t is what we use to hitch drivers to hardware. >>> >>> ifnet is what we use to hitch drivers to the netstack. >>> >>> They should not be tangled. >> >>You mean like dev_t and device_t shouldn't be tangled like we do >>with si_drv1? Oh, wait... > > I don't think any correctly written driver stores it's device_t in > a dev_t. It should store it's softc structure, which should contain > pointers to both. Even if there is a driver which does do that, > it happens inside the device driver, and it does not handicap the > remaining device drivers with its choice.
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. > There is nothing in the "data-model" of the kernel that says that > a network interface corresponds to exactly one hardware device > and more importantly: there shouldn't be either. Agreed. > If all you want is an extra field in "struct ifnet" to hang driver > information on, then by all means add that field. As long as you > give it type "void *" and make it private to the driver I have no > problem with that. Fair enough, though I don't think this is what Brooks was after. -- John Baldwin <[EMAIL PROTECTED]> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "[EMAIL PROTECTED]"
