Introduce helper functions pci_bus_{get|put}() to manage PCI bus
reference count.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Commit 4f535093cf "PCI: Put pci_dev in device tree as early as possible"
moved final fixups from pci_bus_add_device() to pci_device_add().  But
pci_device_add() happens before resource assignment, so BARs may not be
valid yet.

Typical flow for hot-add:

    pciehp_configure_device
      pci_scan_slot
        pci_scan_single_device
          pci_device_add
            pci_fixup_device(pci_fixup_final, dev)  # previous location
      # resource assignment happens here
      pci_bus_add_devices
        pci_bus_add_device
          pci_fixup_device(pci_fixup_final, dev)    # new location

[bhelgaas: changelog, move fixups to pci_bus_add_device()]
Reference: https://lkml.kernel.org/r/20130415182614.GB9224@xanatos
Reported-by: David Bulkow <David.Bulkow@stratus.com>
Tested-by: David Bulkow <David.Bulkow@stratus.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org	# v3.9+

* pci/cleanup:
  PCI: Remove "extern" from function declarations
  PCI: Warn about failures instead of "must_check" functions
  PCI: Remove __must_check from definitions
  PCI: Remove unused variables
  PCI: Move cpci_hotplug_init() proto to header file
  PCI: Make local functions/structs static
  PCI: Fix missing prototype for pcie_port_acpi_setup()

Conflicts:
	drivers/pci/hotplug/acpiphp.h
	include/linux/pci.h

These places capture return values to avoid "must_check" warnings,
but we didn't *do* anything with the return values, which causes
"set but not used" warnings.  We might as well do something instead
of just trying to evade the "must_check" warnings.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Now pci_bus->is_added is only used to guard invoking of
pcibios_fixup_bus() in pci_scan_child_bus(), so just set
it directly after the fixups and remove the other test
and set in pci_bus_add_devices().

[bhelgaas: changelog]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Yinghai Lu <yinghai@kernel.org>

We want to put pci_dev structs in the device tree as soon as possible so
for_each_pci_dev() iteration will not miss them, but driver attachment
needs to be delayed until after pci_assign_unassigned_resources() to make
sure all devices have resources assigned first.

This patch moves device registering from pci_bus_add_devices() to
pci_device_add(), which happens earlier, leaving driver attachment in
pci_bus_add_devices().

It also removes unattached child bus handling in pci_bus_add_devices().
That's not needed because child bus via pci_add_new_bus() is already
in parent bus children list.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

We want to add PCI devices to the device tree as early as possible but
delay attaching drivers.

device_add() adds a device to the device hierarchy and (via
device_attach()) attaches a matching driver and calls its .probe() method.
We want to separate adding the device to the hierarchy from attaching the
driver.

This patch does that by adding "match_driver" in struct pci_dev.  When
false, we return failure from pci_bus_match(), which makes device_attach()
believe there's no matching driver.

Later, we set "match_driver = true" and call device_attach() again, which
now attaches the driver and calls its .probe() method.

[bhelgaas: changelog, explicitly init dev->match_driver,
fold device_attach() call into pci_bus_add_device()]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Firmware may have assigned PCI BARs for hot-added devices, so reserve
those resources before trying to allocate more.

[bhelgaas: move empty weak definition here]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

* pci/mjg-pci-roms-from-efi:
  x86: Use PCI setup data
  PCI: Add support for non-BAR ROMs
  PCI: Add pcibios_add_device
  EFI: Stash ROMs if they're not in the PCI BAR

Platforms may want to provide architecture-specific functionality during
PCI enumeration. Add a pcibios_add_device() call that architectures can
override to do so.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Seth Forshee <seth.forshee@canonical.com>