On 07-Aug-2003 M. Warner Losh wrote: > In message: <[EMAIL PROTECTED]> > Bernd Walter <[EMAIL PROTECTED]> writes: >: The host bridge is not available yet at probing time of the host bridge. >: What we have is the host bridges parent (nexus) in the calling function. >: Either we hand out the parents device_t to nexus_pcib_is_host_bridge, or >: we find it out later. > > Don't you mean legacy_pcib_is_host_bridge? That's where the matching > is done in current right now (well, at least as of my last sync) If > so, passing the host bridge's device down to it would be trivial to > add. It would also allow other CPUs with builtin host bridges to do > similar tricks to the one that is done for the ELAN. These sorts of > features have been very common in other CPU families, and there's no > reason to think that there won't be more of them in the x86 family as > time goes on. > > I'm not sure that adding it to nexus at this stage of the boot would > truly work. Since the legacy device has decided to attach, the nexus > bus is already walking through its children. Adding a child during > that walk strikes me as dangerous, since we have no locking on the > children element of the device_t. Hmmm, looks I just found a source > of problems in my newbus locking code that might explain some weird > things happening when I enable it.... Thanks for making me go look :-)
You would add it to legacy, not nexus. What you probably really want to do is to write a host-PCI bridge driver that attaches to the actual PCI device like 'hostb' and 'agp' do that creates a suitable child bus for the MMCR stuff. This works for both ACPI and non-ACPI and doesn't require hacking the legacy_pcib stuff. -- 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-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
