On Sun, Mar 18, 2012 at 11:42 PM, Yinghai Lu [off-list ref] wrote:

Set up iobusn_resource tree, and register bus number range to it.
Later when need to find bus range, will try to allocate from the tree

Need to test on arches other than x86. esp for ia64 and powerpc that support
 more than on peer root buses.

The patches need to apply to linux v3.3 + pci-next and
       [PATCH -v3] PCI: pci_host_bridge related cleanup

could be found at:
       git://git.kernel.org/pub/scm/linux/kernel/git/yinghai/linux-yinghai.git for-pci-busn-alloc

I started merging this series, but I didn't get very far.  I stopped
at the "resources: Add probe_resource()" patch because I don't think
that interface makes sense yet.  My work-in-progress is at
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git on the
topic/yinghai-busn-alloc branch.

I *could* merge that branch, but I don't think they fix anything (that
would come in the later patches), and there are still some issues in
my mind.

  - I think we really want a [bus 00-ff] resource for each *domain*,
with each host bridge in the domain requesting part of that range.  I
think these patches only track bus number usage within each host
bridge, and I'm not sure there's any place we would detect conflicts
between host bridges.

  - I think I made a mistake in the pci_create_root_bus() and
pci_scan_root_bus() interfaces.  They currently take a bus number and
a list of resources, and we expect the arch to include the bus number
aperture in the list.  The bus number argument should have been
replaced with a bus number aperture resource.  The bus number aperture
is essential, while the MMIO/IO aperture list may be empty.  And it's
stupid to pass both the starting bus number and a bus resource that
contains the starting bus number.  Fixing this would make some of
these patches quite a bit simpler.

  - In some of the arches (sparc, powerpc), you added a bus number
resource right next to existing first_busno, last_busno fields.  So
now that data lives two places, which will bite us later.

Bjorn

Yinghai Lu (30):
 x86, PCI: Add print all root info for not using _CRS path
 x86, PCI: Allocate temp range array in amd_bus pci_root_info probing
 x86, PCI: Merge pcibios_scan_root and pci_scan_bus_on_node
 PCI: Add busn_res into struct pci_bus.
 PCI: Add busn_res operation functions
 PCI: Release busn_res when removing bus
 PCI: Insert busn_res in pci_create_root_bus()
 PCI: Checking busn_res in pci_scan_root_bus()
 PCI: Add default busn_resource
 PCI: Add default busn_res for pci_scan_bus()
 x86, PCI: Add busn_res into resources list for acpi path
 x86, PCI: Put busn resource in pci_root_info for not using _CRS path
 PCI, ia64: Register busn_res for root buses
 PCI, sparc: Register busn_res for root buses
 PCI, powerpc: Register busn_res for root buses
 PCI, parisc: Register busn_res for root buses
 resources: Add probe_resource()
 resources: Replace registered resource in tree.
 PCI: Add pci_bus_extend/shrink_top()
 PCI: Probe safe range that we can use for unassigned bridge.
 PCI: Add pci_bus_replace_busn_res()
 PCI: Allocate bus range instead of use max blindly
 PCI: Strict checking of valid range for bridge
 PCI: Kill pci_fixup_parent_subordinate_busnr()
 PCI: Seperate child bus scanning to two passes overall
 pcmcia: Remove workaround for fixing pci parent bus subordinate
 PCI: Double checking setting for bus register and bus struct.
 PCI, pciehp: Remove not needed bus number range checking
 PCI: More strict checking of valid range for bridge
 PCI: Don't shrink too much for hotplug bridge

 arch/ia64/pci/pci.c                   |    2 +
 arch/powerpc/include/asm/pci-bridge.h |    1 +
 arch/powerpc/kernel/pci-common.c      |   10 +-
 arch/sparc/kernel/pci.c               |    4 +
 arch/sparc/kernel/pci_impl.h          |    1 +
 arch/x86/pci/acpi.c                   |   11 +-
 arch/x86/pci/amd_bus.c                |   14 +-
 arch/x86/pci/bus_numa.c               |   30 ++-
 arch/x86/pci/bus_numa.h               |    4 +-
 arch/x86/pci/common.c                 |   27 +--
 drivers/parisc/dino.c                 |    5 +
 drivers/parisc/lba_pci.c              |    3 +
 drivers/pci/hotplug/pciehp_pci.c      |   12 +-
 drivers/pci/probe.c                   |  439 +++++++++++++++++++++++++++------
 drivers/pci/remove.c                  |    1 +
 drivers/pcmcia/yenta_socket.c         |   75 ------
 include/linux/ioport.h                |    8 +
 include/linux/pci.h                   |    6 +
 kernel/resource.c                     |  175 +++++++++++++-
 19 files changed, 613 insertions(+), 215 deletions(-)

--
1.7.7