[PATCH] PCI bus number management
John Baldwin
jhb at freebsd.org
Thu Feb 6 22:39:12 UTC 2014
On Thursday, February 06, 2014 2:47:09 pm Thomas Hoffmann wrote:
> On Thu, Feb 6, 2014 at 2:37 PM, John Baldwin <jhb at freebsd.org> wrote:
>
> > I have a patch to teach the PCI bus code and PCI-PCI bridge driver to
> > manage
> > PCI bus numbers. The approach is somewhat similar to how NEW_PCIB manages
> > I/O
> > windows for briges. Each bridge creates an rman to manage the bus numbers
> > for
> > all buses and bridges that live below it. Each bus allocates a bus
> > resource
> > from its parent bridge, and child bridges allocate their ranges from their
> > parent devices. At the "top" of the PCI tree, the Host-PCI bridges
> > allocate
> > their respective bus ranges from their PCI domain/segment. There isn't
> > really
> > a device node for PCI domains, so I created a helper API that basically
> > auto-
> > creates a PCI bus rman for each domain on first use and then sub-allocates
> > from that for Host-PCI bridges.
> >
> > The current patch (with some extra debugging) is at
> > http://people.FreeBSD.org/~jhb/patches/pci_bus_rman.3.patch
> >
> > I would like to commit this to HEAD soon but thought I would post it for
> > some
> > pre-commit testing for the brave. :) If you are really brave, try booting
> > with 'hw.pci.clear_buses=1' which will force the kernel to renumber all
> > buses
> > in the system. If you are really, really brave, try booting with
> > 'hw.pci.clear_bars=1', 'hw.pci.clear_buses=1', and 'hw.pci.clear_pcib=1'.
> > (My
> > laptop survives with all those set)
> >
> > Note that the patch only enables bus number management on amd64 and i386.
> > I
> > believe ia64 just needs to define PCI_RES_BUS for this to work since it
> > mandates ACPI. Porting this to other platforms requires handling
> > PCI_RES_BUS
> > rseources for Host-PCI bridges in bus_alloc_resource(),
> > bus_adjust_resource(),
> > and bus_release_resource().
> >
> > --
> > John Baldwin
> >
>
> I get a "404 - Not Found" trying to follow the link.
Oops, it is:
http://people.freebsd.org/~jhb/patches/pci_bus_rman3.patch
--
John Baldwin
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