linux.git/drivers/pci/hotplug/pci_hotplug_core.c, branch v2.6.29

PCI: Hotplug core: remove 'name'

2008-10-22T23:42:43+00:00

Now that the PCI core manages the 'name' for each individual
hotplug driver, and all drivers (except rpaphp) have been converted
to use hotplug_slot_name(), there is no need for the PCI hotplug
core to drag around its own copy of name either.

Cc: kristen.c.accardi@intel.com
Cc: matthew@wil.cx
Acked-by: Kenji Kaneshige 
Signed-off-by: Alex Chiang 
Signed-off-by: Jesse Barnes

PCI: prevent duplicate slot names

2008-10-22T23:42:39+00:00

Prevent callers of pci_create_slot() from registering slots with
duplicate names. This condition occurs most often when PCI hotplug
drivers are loaded on platforms with broken firmware that assigns
identical names to multiple slots.

We now rename these duplicate slots on behalf of the user.

If firmware assigns the name N to multiple slots, then:

	The first registered slot is assigned N
	The second registered slot is assigned N-1
	The third registered slot is assigned N-2
	etc.

This is the permanent fix mentioned in earlier commits d6a9e9b4 and
167e782e (shpchp/pciehp: Rename duplicate slot name...).

We take advantage of the new 'hotplug' parameter in pci_create_slot()
to prevent a slot create/rename race between hotplug drivers and
detection drivers.

	Scenario A:
	hotplug driver                  detection driver
	--------------                  ----------------
	pci_create_slot(hotplug=set)
					pci_create_slot(hotplug=NULL)

The hotplug driver creates the slot with its desired name, and then
releases the semaphore. Now, the detection driver tries to create
the same slot, but it already exists. We don't care about renaming,
so return the existing slot.

	Scenario B:
	hotplug driver                  detection driver
	--------------                  ----------------
					pci_create_slot(hotplug=NULL)
	pci_create_slot(hotplug=set)

The detection driver creates the slot with name "X". Then the hotplug
driver tries to create the same slot, but wants the name "Y" instead.
We detect that we're trying to create the same slot and that we also
want a rename, so rename the slot to "Y" and return.

	Scenario C:
	hotplug driver                  hotplug driver
	--------------                  ----------------
	pci_create_slot(hotplug=set)
					pci_create_slot(hotplug=set)

Two separate hotplug drivers are attempting to claim the slot and
are passing valid hotplug_slot args to pci_create_slot(). We detect
that the slot already has a ->hotplug callback, prevent a rename,
and return -EBUSY.

Cc: kristen.c.accardi@intel.com
Cc: matthew@wil.cx
Acked-by: Kenji Kaneshige 
Signed-off-by: Alex Chiang 
Signed-off-by: Jesse Barnes

PCI Hotplug: serialize pci_hp_register and pci_hp_deregister

2008-10-22T23:42:38+00:00

Convert the pci_hotplug_slot_list_lock, which only protected the
list of hotplug slots, to a pci_hp_mutex which now protects both
interfaces.

Signed-off-by: Kenji Kaneshige 
Signed-off-by: Alex Chiang 
Signed-off-by: Jesse Barnes

PCI: update pci_create_slot() to take a 'hotplug' param

2008-10-22T23:42:38+00:00

Slot detection drivers can co-exist with hotplug drivers. The names
of the detected/claimed slots may be different depending on module
load order.

For legacy reasons, we need to allow hotplug drivers to override
the slot name if a detection driver is loaded first (and they find
the same slots).

Creating and overriding slot names should be an atomic operation,
otherwise you get a locking nightmare as various drivers race to
call pci_create_slot().

pci_create_slot() is already serialized by grabbing the pci_bus_sem.

We update the API and add a 'hotplug' param, which is:

	set if the caller is a hotplug driver
	NULL if the caller is a detection driver

pci_create_slot() does not actually use the 'hotplug' parameter in this
patch. A later patch will add the logic that uses it.

Cc: kristen.c.accardi@intel.com
Cc: matthew@wil.cx
Acked-by: Kenji Kaneshige 
Signed-off-by: Alex Chiang 
Signed-off-by: Jesse Barnes

PCI Hotplug core: add 'name' param pci_hp_register interface

2008-10-22T23:42:37+00:00

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 
Reviewed-by: Matthew Wilcox 
Signed-off-by: Alex Chiang 
Signed-off-by: Jesse Barnes

PCI hotplug: fix get_##name return value problem

2008-10-20T18:01:50+00:00

The commit 356a9d6f3dd283f83861adf1ac909879f0e66411 (PCI: fix hotplug
get_##name return value problem) doesn't seem to be merged properly.
Because of this, PCI hotplug no longer works (Read/Write PCI hotplug
files always returns -ENODEV).

This patch fixes wrong check of try_module_get() return value check in
get_##name().

Signed-off-by: Kenji Kaneshige 
Signed-off-by: Jesse Barnes

PCI: fix hotplug get_##name return value problem

2008-10-20T17:54:25+00:00

Currently, get_##name in pci_hotplug_core.c will return 0 if module
unload wins the race between unload & reading the hotplug file.  Fix
that case to return -ENODEV like it should.

Reviewed-by: Alex Chiang 
Reviewed-by: Matthew Wilcox 
Signed-off-by: Yu Zhao 
Signed-off-by: Jesse Barnes

Remove unnecessary 'tmp' variable from pci_hp_register().

2008-06-25T22:58:39+00:00

Signed-off-by: Kenji Kaneshige 
Signed-off-by: Jesse Barnes

PCI: fixup kdoc blocks for hotplug functions

2008-06-25T22:27:34+00:00

A few warnings snuck in as parameters were added or renamed.

Signed-off-by: Jesse Barnes

PCI: ACPI PCI slot detection driver

2008-06-10T21:37:14+00:00

Detect all physical PCI slots as described by ACPI, and create entries in
/sys/bus/pci/slots/.

Not all physical slots are hotpluggable, and the acpiphp module does not
detect them.  Now we know the physical PCI geography of our system, without
caring about hotplug.

[kaneshige.kenji@jp.fujitsu.com: export-kobject_rename-for-pci_hotplug_core]
Signed-off-by: Kenji Kaneshige 
Acked-by: Greg KH 
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix build with CONFIG_DMI=n]
Signed-off-by: Alex Chiang 
Cc: Greg KH 
Cc: Kristen Carlson Accardi 
Cc: Len Brown 
Acked-by: Len Brown 
Acked-by: Kenji Kaneshige 
Signed-off-by: Andrew Morton 
Signed-off-by: Andrew Morton 
Signed-off-by: Jesse Barnes