Commits · 0ad772ec464d3fcf9d210836b97e654f393606c4 · nexedi / linux

22 Oct, 2008 18 commits

PCI, PCI Hotplug: introduce slot_name helpers · 0ad772ec

Alex Chiang authored Oct 20, 2008

In preparation for cleaning up the various hotplug drivers
such that they don't have to manage their own 'name' parameters
anymore, we provide the following convenience functions:

	pci_slot_name()
	hotplug_slot_name()

These helpers will be used by individual hotplug drivers.

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>

0ad772ec

PCI: cpqphp: stop managing hotplug_slot->name · 30ac7acd

Alex Chiang authored Oct 20, 2008

We no longer need to manage our version of hotplug_slot->name
since the PCI and hotplug core manage it on our behalf.

Now, we simply advise the PCI core of the name that we would
like, and let the core take care of the rest.

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>

30ac7acd

PCI: cpci_hotplug: stop managing hotplug_slot->name · d6c479e0

Alex Chiang authored Oct 20, 2008

We no longer need to manage our version of hotplug_slot->name
since the PCI and hotplug core manage it on our behalf.

Now, we simply advise the PCI core of the name that we would
like, and let the core take care of the rest.

Cc: kristen.c.accardi@intel.com
Cc: scottm@somanetworks.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>

d6c479e0

PCI: acpiphp: remove 'name' parameter · df77cd10

Alex Chiang authored Oct 20, 2008

We do not need to manage our own name parameter, especially since
the PCI core can change it on our behalf, in the case of duplicate
slot names.

Remove 'name' from acpiphp's version of struct slot.

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>

df77cd10

PCI: prevent duplicate slot names · 5fe6cc60

Alex Chiang authored Oct 20, 2008

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 <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

5fe6cc60

PCI Hotplug: serialize pci_hp_register and pci_hp_deregister · 95cb9093

Kenji Kaneshige authored Oct 20, 2008

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 <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

95cb9093

PCI: update pci_create_slot() to take a 'hotplug' param · 828f3768

Alex Chiang authored Oct 20, 2008

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 <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

828f3768

PCI: rename pci_update_slot_number to pci_renumber_slot · d25b7c8d

Alex Chiang authored Oct 20, 2008

The GPL exported symbol pci_update_slot_number has been renamed to
pci_renumber_slot. Some of the safety checks were unnecessary and
were removed.

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>

d25b7c8d

PCI Hotplug core: add 'name' param pci_hp_register interface · 1359f270

Alex Chiang authored Oct 20, 2008

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>

1359f270

Remove PCI hotplug core MAINTAINERS entry · 48ff96ce

Jesse Barnes authored Oct 21, 2008

Per discussion w/Kristen at the LPC PCI BoF, the core hotplug code doesn't
really need a separate maintainer, so remove the entry (but leave the driver
specific ones).
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

48ff96ce

PCI: include io.h in pci.h so that ioremap_nocache is defined · 64c7f63c

Jesse Barnes authored Oct 21, 2008

Ingo pointed out that the m32r build was broken by pci_ioremap.  It looks like
some files include pci.h w/o including io.h.  The latter defines ioremap_* if
present, so it makes sense to include it in pci.h now that we have pci_ioremap
there.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

64c7f63c

PCI: add support for function level reset · 8dd7f803

Sheng Yang authored Oct 21, 2008

Sometimes, it's necessary to enable software's ability to quiesce and
reset endpoint hardware with function-level granularity, so provide
support for it.

The patch implement Function Level Reset(FLR) feature following PCI-e
spec. And this is the first step. We would add more generic method, like
D0/D3, to allow more devices support this function.

The patch contains two functions. pcie_reset_function() is the new
driver API, and, contains some action to quiesce a device.  The other
function is a helper:  pcie_execute_reset_function() just executes the
reset for a particular device function.

Current the usage model is in KVM. Function reset is necessary for
assigning device to a guest, or moving it between partitions.

For Function Level Reset(FLR), please refer to PCI Express spec chapter
6.6.2.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

8dd7f803

PCI: Fix reference counting bug · c4ed02fa

Matthew Wilcox authored Oct 20, 2008

pci_get_subsys() will decrement the reference count of the device that
it starts searching from. Unfortunately, the pci_find_device() interface
will already have decremented the reference count of the device earlier,
so the device will end up losing all reference counts and be freed.

We can fix this by incrementing the reference count of the device to
start searching from before calling pci_get_subsys().
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

c4ed02fa