For PCI devices, pci_bus_assign_resources() must be called to set up the
pci_device->resource array before pci_bus_add_devices() can be called, else
attempts to load drivers results in BAR collision errors where there are none.
This is not done in fakephp, so devices can be "unplugged" but scanning the
parent bus won't bring the devices back due to resource unallocation.  Move the
pci_bus_add_device-calling logic into pci_rescan_bus and preface it with a call
to pci_bus_assign_resources so that we only have to (re)allocate resources once
per bus where a new device is found.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

pci_get_slot does a pci_dev_get, so pci_dev_put needs to be called in an
error case.

An alterative would be to move the test_and_set_bit before the call to
pci_get_slot.

The problem was fixed using the following semantic patch.
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
local idexpression *n;
statement S1,S2;
expression E,E1;
expression *ptr != NULL;
type T,T1;
@@

(
if (!(n = pci_get_slot(...))) S1
|
n = pci_get_slot(...)
)
<... when != pci_dev_put(n)
    when != if (...) { <+... pci_dev_put(n) ...+> }
    when != true !n  || ...
    when != n = (T)E
    when != E = n
if (!n || ...) S2
...>
(
  return \(0\|<+...n...+>\|ptr\);
|
+ pci_dev_put(n);
return ...;
|
pci_dev_put(n);
|
n = (T1)E1
|
E1 = n
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

The PCI core now manages slot names on behalf of slot detection
and slot hotplug drivers, including the handling of duplicate
slot names.

We can use the fakephp driver to help test the new functionality.
Add a 'dup_slots' module param to force fakephp to create multiple
slots with the same name. We can then verify that the PCI core
correctly renamed the slots.

	sapphire:/sys/bus/pci/slots # modprobe fakephp dup_slots
	sapphire:/sys/bus/pci/slots # ls
	fake    fake-10  fake-3  fake-5  fake-7  fake-9
	fake-1  fake-2   fake-4  fake-6  fake-8

Cc: kristen.c.accardi@intel.com
Cc: matthew@wil.cx
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Remove 'name' from fakephp's struct dummy_slot, as the PCI core
will now manage our slot name for us.

Cc: jbarnes@virtuousgeek.org
Cc: kristen.c.accardi@intel.com
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Update pci_hp_register() to take a const char *name parameter.

The motivation for this is to clean up the individual hotplug
drivers so that each one does not have to manage its own name.
The PCI core should be the place where we manage the name.

We update the interface and all callsites first, in a
"no functional change" manner, and clean up the drivers later.

Cc: kristen.c.accardi@intel.com
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Commit fe99740cac117f208707488c03f3789cf4904957 (construct one
fakephp slot per PCI slot) introduced a regression, causing a
deadlock when removing a PCI device.

We also never actually removed the device from the PCI core.

So we:

	- remove the device from the PCI core
	- do not directly call remove_slot() to prevent deadlock

Yu Zhao reported and diagnosed this defect.

Signed-off-by: Alex Chiang <achiang@hp.com>
Acked-by: Yu Zhao <yu.zhao@intel.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Currently, /sys/bus/pci/slots/ only exposes hotplug attributes when a
hotplug driver is loaded, but PCI slots have attributes such as address,
speed, width, etc.  that are not related to hotplug at all.

Introduce pci_slot as the primary data structure and kobject model.
Hotplug attributes described in hotplug_slot become a secondary
structure associated with the pci_slot.

This patch only creates the infrastructure that allows the separation of
PCI slot attributes and hotplug attributes.  In this patch, the PCI
hotplug core remains the only user of this infrastructure, and thus,
/sys/bus/pci/slots/ will still only become populated when a hotplug
driver is loaded.

A later patch in this series will add a second user of this new
infrastructure and demonstrate splitting the task of exposing pci_slot
attributes from hotplug_slot attributes.

  - Make pci_slot the primary sysfs entity. hotplug_slot becomes a
    subsidiary structure.
    o pci_create_slot() creates and registers a slot with the PCI core
    o pci_slot_add_hotplug() gives it hotplug capability

  - Change the prototype of pci_hp_register() to take the bus and
    slot number (on parent bus) as parameters.

  - Remove all the ->get_address methods since this functionality is
    now handled by pci_slot directly.

[achiang@hp.com: rpaphp-correctly-pci_hp_register-for-empty-pci-slots]
Tested-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: make headers_check happy]
[akpm@linux-foundation.org: nuther build fix]
[akpm@linux-foundation.org: fix typo in #include]
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Cc: Greg KH <greg@kroah.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: Len Brown <lenb@kernel.org>
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Register one slot per slot, rather than one slot per function.  Change the
name of the slot to fake%d instead of the pci address.

Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Cc: Greg KH <greg@kroah.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The 'power' attribute of the fakephp driver originally only let one turn a
slot off.  If one tried to turn a slot on (echo 1 > .../power), it would
return ENODEV, as fakephp did not support this function.

An old (pre-git) patch changed this:
2004/11/11 16:33:31-08:00 jdittmer
[PATCH] fakephp: add pci bus rescan ability
http://article.gmane.org/gmane.linux.kernel/251183

Now writing "1" to the power attribute has the effect of triggering a bus
rescan, but it still returns ENODEV, probably an oversight in the above
patch.

Using the BusyBox echo will not produce an error message, but will
trigger *two* bus rescans (and return an exit code of 1):
~ # strace echo -n 1 > /sys/bus/pci/slots/0000:00:00.0/power
...
write(1, "1", 1)                        = -1 ENODEV (No such device)
write(1, "1", 1)                        = -1 ENODEV (No such device)
exit(1)                                 = ?

Using cp gives a write error, even though the write did happen and a rescan
was triggered:
~ # echo -n 1 > tmp ; cp tmp /sys/bus/pci/slots/0000:00:00.0/power
cp: Write Error: No such device

It seems much better to return success instead of failure.  The actual
status of the bus rescan is hard to return.  It happens asynchronously in a
work thread, so the sysfs store functions returns before any status is
ready (the whole point of the work queue).  And even if it didn't do this,
the rescan doesn't have any clear status to return.

Signed-off-by: Trent Piepho <tpiepho@freescale.com>
CC: Jan Dittmer <jdittmer@ppp0.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>