* pci/yinghai-root-bus-hotplug:
  PCI: Put pci_dev in device tree as early as possible
  PCI: Skip attaching driver in device_add()
  PCI: acpiphp: Keep driver loaded even if no slots found
  PCI/ACPI: Print info if host bridge notify handler installation fails
  PCI: acpiphp: Move host bridge hotplug to pci_root.c
  PCI/ACPI: acpiphp: Rename alloc_acpiphp_hp_work() to alloc_acpi_hp_work()
  PCI: Make device create/destroy logic symmetric
  PCI: Fix reference count leak in pci_dev_present()
  PCI: Set pci_dev dev_node early so IOAPIC irq_descs are allocated locally
  PCI: Add root bus children dev's res to fail list
  PCI: acpiphp: Add is_hotplug_bridge detection

Conflicts:
	drivers/pci/pci.h

* pci/acpi-scan2:
  ACPI / scan: Drop acpi_bus_add() and use acpi_bus_scan() instead
  ACPI: update ej_event interface to take acpi_device
  ACPI / scan: Add second pass to acpi_bus_trim()
  ACPI / scan: Change the implementation of acpi_bus_trim()
  ACPI / scan: Drop the second argument of acpi_bus_trim()
  ACPI / scan: Drop the second argument of acpi_device_unregister()
  ACPI: Remove the ops field from struct acpi_device
  ACPI: remove unused acpi_op_bind and acpi_op_unbind
  ACPI / scan: Fix check of device_attach() return value.

* pci/yijing-ari:
  PCI: shpchp: Iterate over all devices in slot, not functions 0-7
  PCI: sgihp: Iterate over all devices in slot, not functions 0-7
  PCI: cpcihp: Iterate over all devices in slot, not functions 0-7
  PCI: pciehp: Iterate over all devices in slot, not functions 0-7
  PCI: Consolidate "next-function" functions
  PCI: Rename pci_enable_ari() to pci_configure_ari()
  PCI: Enable ARI if dev and upstream bridge support it; disable otherwise

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>

Could have root bus hot-added later and there may be slots that need
acpiphp.

The result returned by acpiphp_get_num_slots() is meaningless, because
the bridge the slots are under may be added after this function has been
called, so drop acpiphp_get_num_slots() and the code using it.
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>

acpi_install_notify_handler() could fail.  So check the exit status
and give a better debug info.
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
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>

The acpiphp driver is confusing because it contains partial support for PCI
host bridge hotplug as well as support for hotplug of PCI devices.

This patch moves the host bridge hot-add support to pci_root.c and adds
hot-remove support in pci_root.c.

How to test it: if sci_emu patch is applied, find out root bus number to
ACPI root name mapping from dmesg or /sys.  To remove root bus:

  echo "\_SB.PCIB 3" > /sys/kernel/debug/acpi/sci_notify

To add back root bus:

  echo "\_SB.PCIB 1" > /sys/kernel/debug/acpi/sci_notify
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>

Will need to use it for PCI root bridge hotplug support, so rename
*acpiphp* to *acpi* and move to osc.c.  Also make kacpi_hotplug_wq static
after that.
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>
CC: Len Brown <lenb@kernel.org>
CC: linux-acpi@vger.kernel.org

According to device model documentation, the way to create/destroy PCI
devices should be symmetric.  The rule is to either use
  1) device_register()/device_unregister()
or
  2) device_initialize()/device_add()/device_del()/put_device().

So change PCI core logic to follow the rule and get rid of the redundant
pci_dev_get()/pci_dev_put() pair.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
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>

Function pci_get_dev_by_id() takes a reference on the pci_dev returned, so
pci_dev_present() should release the corresponding reference.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
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>

Otherwise irq_desc for PCI bridge with hot-added IOAPIC may not be
allocated on the local node.
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 can stop trying according to try_number now and do not need to use
root_bus checking as stop sign.

In extreme case we could need to reallocate resource for device just
under root bus.  For PCI root bus hot-add, we need to retry to assign
resources to PCI devices just under pci root bus.
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>

When system support hotplug bridge with children hotplug slots, we need
to make sure that parent bridge get preallocated resource so later when
device is plugged into children slot, those children devices will get
resource allocated.

We do not meet this problem, because for PCIe hotplug card, when acpiphp
is used, pci_scan_bridge will set that for us when detect hotplug bit in
slot cap.
Reported-and-tested-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Merge branch 'acpi-scan' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm into pci/acpi-scan2

* 'acpi-scan' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / scan: Drop acpi_bus_add() and use acpi_bus_scan() instead
  ACPI: update ej_event interface to take acpi_device
  ACPI / scan: Add second pass to acpi_bus_trim()
  ACPI / scan: Change the implementation of acpi_bus_trim()
  ACPI / scan: Drop the second argument of acpi_bus_trim()
  ACPI / scan: Drop the second argument of acpi_device_unregister()
  ACPI: Remove the ops field from struct acpi_device
  ACPI: remove unused acpi_op_bind and acpi_op_unbind
  ACPI / scan: Fix check of device_attach() return value.

Iterate through devices in a slot by using the upstream bridge's
"bus->devices" list instead of assuming they are functions 0-7.  It's
possible there are several slots on the same pci_bus, so restrict it to
only devices matching this slot's device number.

ARI (which allows functions 0-255) is a PCIe-only feature, and this is
a PCI hotplug driver, so we shouldn't find anything other than functions
0-7, but it's better to iterate the same way as other hotplug drivers.

[bhelgaas: changelog, check PCI_SLOT, fix shpchp_unconfigure_device()]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Iterate through devices in a slot by using the upstream bridge's
"bus->devices" list instead of assuming they are functions 0-7.  It's
possible there are several slots on the same pci_bus, so restrict it to
only devices matching this slot's device number.

ARI (which allows functions 0-255) is a PCIe-only feature, and this is
a PCI hotplug driver, so we shouldn't find anything other than functions
0-7, but it's better to iterate the same way as other hotplug drivers.

[bhelgaas: changelog, check PCI_SLOT, fix disable_slot()]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Iterate through devices in a slot by using the upstream bridge's
"bus->devices" list instead of assuming they are functions 0-7.  It's
possible there are several slots on the same pci_bus, so restrict it to
only devices matching this slot's device number.

ARI (which allows functions 0-255) is a PCIe-only feature, and this is
a PCI hotplug driver, so we shouldn't find anything other than functions
0-7, but it's better to iterate the same way as other hotplug drivers.

[bhelgaas: changelog, check PCI_SLOT, fix cpci_unconfigure_slot()]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Currently, we enumerate devices in a slot with pci_scan_slot(), then
iterate through all the devices we found by looking for functions 0-7.  But
that's wrong for ARI devices, which may have function numbers up to 255.

This means that when we hot-add an ARI device, pciehp only initializes
functions 0-7, and other functions don't work correctly.  Additionally, if
we hot-remove the device, pciehp only removes functions 0-7, leaving stale
pci_dev structures for any other functions.

This patch fixes the problem by iterating over devices in a slot by using
the upstream bridge's "bus->devices" list instead.

[bhelgaas: changelog]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

There are several next_fn functions (no_next_fn, next_trad_fn,
next_ari_fn); consolidate them in next_fn() to simplify the code.

[bhelgaas: make next_fn() static, rework control flow]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

pci_enable_ari() now supports enabling or disabling ARI forwarding.  So
rename pci_enable_ari() to pci_configure_ari() for easy understanding.

No functional change.

[bhelgaas: changelog]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Currently, we enable ARI in a device's upstream bridge if the bridge and
the device support it.  But we never disable ARI, even if the device is
removed and replaced with a device that doesn't support ARI.

This means that if we hot-remove an ARI device and replace it with a
non-ARI multi-function device, we find only function 0 of the new device
because the upstream bridge still has ARI enabled, and next_ari_fn()
only returns function 0 for the new non-ARI device.

This patch disables ARI in the upstream bridge if the device doesn't
support ARI.  See the PCIe spec, r3.0, sec 6.13.

[bhelgaas: changelog, function comment]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

The only difference between acpi_bus_scan() and acpi_bus_add() is the
invocation of acpi_update_all_gpes() in the latter which in fact is
unnecessary, because acpi_update_all_gpes() has already been called
by acpi_scan_init() and the way it is implemented guarantees the next
invocations of it to do nothing.

For this reason, drop acpi_bus_add() and make all its callers use
acpi_bus_scan() directly instead of it.  Additionally, rearrange the
code in acpi_scan_init() slightly to improve the visibility of the
acpi_update_all_gpes() call in there.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>

* pci/rafael-set-root-bridge-handle:
  ACPI / PCI: Set root bridge ACPI handle in advance

Should use acpi_device pointer directly instead of use handle and
get the device pointer again later.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Make acpi_bus_trim() work in analogy with acpi_bus_scan() and carry
out two passes such that ACPI drivers will be detached from device
nodes being removed in the first pass and the device nodes themselves
will be removed in the second pass.

For this purpose split the driver unregistration out of
acpi_bus_remove() into a new routine, acpi_bus_device_detach(), that
will be executed by acpi_bus_trim() in the additional first pass as
a post-order callback.

This is necessary, because some ACPI drivers' .remove() routines
unregister struct device objects associated with the ACPI device
nodes being removed and that needs to happen while the ACPI
device nodes are still around (for example, in case they need to be
used for power management or similar things at that time).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>

The current acpi_bus_trim() implementation is not really
straightforward and may be simplified significantly by using
acpi_walk_namespace() with acpi_bus_remove() as a post-order
callback.

Observe that acpi_bus_remove(), as called by acpi_bus_trim(), cannot
actually fail, because its first argument is guaranteed not to be
NULL thanks to the acpi_bus_get_device() check in acpi_bus_trim(),
so simply move the acpi_bus_get_device() check to acpi_bus_remove()
and use acpi_walk_namespace() to execute it for every device under
start->handle as a post-order callback.  The, run it directly for
start->handle itself.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>

All callers of acpi_bus_trim() pass 1 (true) as the second argument
of it, so remove that argument entirely and change acpi_bus_trim()
to always behave as though it were 1.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>

Drop the second argument of acpi_device_unregister(), type, which is
not used by that function.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>

The ops field in struct acpi_device is not used anywhere, so remove
it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>

With commit f2a33cde55a03 "ACPI: Drop ACPI device .bind() and .unbind()
callbacks", acpi_op_bind and acpi_op_unbind are not used any more. So
remove them.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The ACPI handles of PCI root bridges need to be known to
acpi_bind_one(), so that it can create the appropriate
"firmware_node" and "physical_node" files for them, but currently
the way it gets to know those handles is not exactly straightforward
(to put it lightly).

This is how it works, roughly:

  1. acpi_bus_scan() finds the handle of a PCI root bridge,
     creates a struct acpi_device object for it and passes that
     object to acpi_pci_root_add().

  2. acpi_pci_root_add() creates a struct acpi_pci_root object,
     populates its "device" field with its argument's address
     (device->handle is the ACPI handle found in step 1).

  3. The struct acpi_pci_root object created in step 2 is passed
     to pci_acpi_scan_root() and used to get resources that are
     passed to pci_create_root_bus().

  4. pci_create_root_bus() creates a struct pci_host_bridge object
     and passes its "dev" member to device_register().

  5. platform_notify(), which for systems with ACPI is set to
     acpi_platform_notify(), is called.

So far, so good.  Now it starts to be "interesting".

  6. acpi_find_bridge_device() is used to find the ACPI handle of
     the given device (which is the PCI root bridge) and executes
     acpi_pci_find_root_bridge(), among other things, for the
     given device object.

  7. acpi_pci_find_root_bridge() uses the name (sic!) of the given
     device object to extract the segment and bus numbers of the PCI
     root bridge and passes them to acpi_get_pci_rootbridge_handle().

  8. acpi_get_pci_rootbridge_handle() browses the list of ACPI PCI
     root bridges and finds the one that matches the given segment
     and bus numbers.  Its handle is then used to initialize the
     ACPI handle of the PCI root bridge's device object by
     acpi_bind_one().  However, this is *exactly* the ACPI handle we
     started with in step 1.

Needless to say, this is quite embarassing, but it may be avoided
thanks to commit f3fd0c8a (ACPI: Allow ACPI handles of devices to be
initialized in advance), which makes it possible to initialize the
ACPI handle of a device before passing it to device_register().

Accordingly, add a new __weak routine, pcibios_root_bridge_prepare(),
defaulting to an empty implementation that can be replaced by the
interested architecutres (x86 and ia64 at the moment) with functions
that will set the root bridge's ACPI handle before its dev member is
passed to device_register().  Make both x86 and ia64 provide such
implementations of pcibios_root_bridge_prepare() and remove
acpi_pci_find_root_bridge() and acpi_get_pci_rootbridge_handle() that
aren't necessary any more.

Included is a fix for breakage on systems with non-ACPI PCI host
bridges from Bjorn Helgaas.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Since device_attach() returns 1 on success (a driver has been bound
to the device), the check against its return value in
acpi_bus_device_attach() should modified to take that into accout.
Make it so.

[rjw: Subject and changelog.]
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

* pci/yinghai-survey-resources+acpi-scan:
  ACPI / scan: Treat power resources in a special way
  ACPI: Remove unused struct acpi_pci_root.id member
  ACPI: Drop ACPI device .bind() and .unbind() callbacks
  ACPI / PCI: Move the _PRT setup and cleanup code to pci-acpi.c
  ACPI / PCI: Rework the setup and cleanup of device wakeup
  ACPI: Add .setup() and .cleanup() callbacks to struct acpi_bus_type
  ACPI: Make acpi_bus_scan() and acpi_bus_add() take only one argument
  ACPI: Replace ACPI device add_type field with a match_driver flag
  ACPI: Drop the second argument of acpi_bus_scan()
  ACPI: Remove the arguments of acpi_bus_add() that are not used
  ACPI: Remove acpi_start_single_object() and acpi_bus_start()
  ACPI / PCI: Fold acpi_pci_root_start() into acpi_pci_root_add()
  ACPI: Change the ordering of acpi_bus_check_add()
  ACPI: Replace struct acpi_bus_ops with enum type
  ACPI: Reduce the usage of struct acpi_bus_ops
  ACPI: Make acpi_bus_add() and acpi_bus_start() visibly different
  ACPI: Change the ordering of PCI root bridge driver registrarion
  ACPI: Separate adding ACPI device objects from probing ACPI drivers

Merge branch 'acpi-scan' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm into pci/yinghai-survey-resources+acpi-scan

* 'acpi-scan' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / scan: Treat power resources in a special way
  ACPI: Remove unused struct acpi_pci_root.id member
  ACPI: Drop ACPI device .bind() and .unbind() callbacks
  ACPI / PCI: Move the _PRT setup and cleanup code to pci-acpi.c
  ACPI / PCI: Rework the setup and cleanup of device wakeup
  ACPI: Add .setup() and .cleanup() callbacks to struct acpi_bus_type
  ACPI: Make acpi_bus_scan() and acpi_bus_add() take only one argument
  ACPI: Replace ACPI device add_type field with a match_driver flag
  ACPI: Drop the second argument of acpi_bus_scan()
  ACPI: Remove the arguments of acpi_bus_add() that are not used
  ACPI: Remove acpi_start_single_object() and acpi_bus_start()
  ACPI / PCI: Fold acpi_pci_root_start() into acpi_pci_root_add()
  ACPI: Change the ordering of acpi_bus_check_add()
  ACPI: Replace struct acpi_bus_ops with enum type
  ACPI: Reduce the usage of struct acpi_bus_ops
  ACPI: Make acpi_bus_add() and acpi_bus_start() visibly different
  ACPI: Change the ordering of PCI root bridge driver registrarion
  ACPI: Separate adding ACPI device objects from probing ACPI drivers

Conflicts:
	drivers/acpi/pci_root.c

* pci/yinghai-survey-resources:
  x86/PCI: Implement pcibios_resource_survey_bus()
  PCI/ACPI: Reserve firmware-allocated resources for hot-added root buses
  x86/PCI: Keep resource allocation functions after boot
  x86/PCI: Don't track firmware-assigned BAR values for hot-added devices
  x86/PCI: Factor out pcibios_allocate_dev_rom_resource()
  x86/PCI: Allocate resources on a per-bus basis for hot-adding root buses
  x86/PCI: Factor out pcibios_allocate_dev_resources()
  x86/PCI: Factor out pcibios_allocate_bridge_resources()

* pci/misc:
  PCI: cpqphp: Cleanup and remove unreachable paths
  PCI: Drop "__" prefix on __pci_enable_device_flags()
  PCI: Use "unsigned long" for __pci_enable_device_flags to match ioport.h
  mn10300/PCI: Remove unused pci_root_bus
  frv/PCI: Remove unused pci_root_bus
  x86/PCI: Remove unused pci_root_bus

During testing remove/rescan root bus 00, found
[  338.142574] bus: 'pci': really_probe: probing driver ata_piix with device 0000:00:01.1
[  338.146788] ata_piix 0000:00:01.1: device not available (can't reserve [io  0x01f0-0x01f7])
[  338.150565] ata_piix: probe of 0000:00:01.1 failed with error -22

because that fixed resource is not claimed.
For bootint path it is claimed in  from
        arch/x86/pci/i386.c::pcibios_allocate_resources()

Claim those resources, so on the remove/rescan will still use old
resources.

It is some kind honoring FW setting in the registers during hot add.
esp root-bus hot add is through acpi, BIOS has chance to set some registers
before handing over.

[bhelgaas: move weak definition to patch that uses it]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.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>

The PCI resource allocation functions will be used for hot-added
devices, so keep them around.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>