Although the majority of PCI devices can generate PMEs that in
principle may be used to wake up devices suspended at run time,
platform support is generally necessary to convert PMEs into wake-up
events that can be delivered to the kernel.  If ACPI is used for this
purpose, PME signals generated by a PCI device will trigger the ACPI
GPE associated with the device to generate an ACPI wake-up event that
we can set up a handler for, provided that everything is configured
correctly.

Unfortunately, the subset of PCI devices that have GPEs associated
with them is quite limited.  The devices without dedicated GPEs have
to rely on the GPEs associated with other devices (in the majority of
cases their upstream bridges and, possibly, the root bridge) to
generate ACPI wake-up events in response to PME signals from them.

Add ACPI platform support for PCI PME wake-up:
o Add a framework making is possible to use ACPI system notify
  handlers for run-time PM.
o Add new PCI platform callback ->run_wake() to struct
  pci_platform_pm_ops allowing us to enable/disable the platform to
  generate wake-up events for given device.  Implemet this callback
  for the ACPI platform.
o Define ACPI wake-up handlers for PCI devices and PCI root buses and
  make the PCI-ACPI binding code register wake-up notifiers for all
  PCI devices present in the ACPI tables.
o Add function pci_dev_run_wake() which can be used by PCI drivers to
  check if given device is capable of generating wake-up events at
  run time.

Developed in cooperation with Matthew Garrett <mjg@redhat.com>.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Add function pci_check_pme_status() that will check the PME status
bit of given device and clear it along with the PME enable bit.  It
will be necessary for PCI run-time power management.

Based on a patch from Shaohua Li <shaohua.li@intel.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Currently, drivers/pci/quirks.c is built unconditionally, but if
CONFIG_PCI_QUIRKS is unset, the only things actually built in this
file are definitions of global variables and empty functions (due to
the #ifdef CONFIG_PCI_QUIRKS embracing all of the code inside the
file).  This is not particularly nice and if someone overlooks
the #ifdef CONFIG_PCI_QUIRKS, build errors are introduced.

To clean that up, move the definitions of the global variables in
quirks.c that are always built to pci.c, move the definitions of
the empty functions (compiled when CONFIG_PCI_QUIRKS is unset) to
headers (additionally make these functions static inline) and modify
drivers/pci/Makefile so that quirks.c is only built if
CONFIG_PCI_QUIRKS is set.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

It turns out that some PCI devices require extra delays when changing
power state from D3 to D0 (and the other way around).  Although this
is against the PCI specification, we can handle it quite easily by
allowing drivers to define arbitrary D3 delays for devices known to
require extra time for switching power states.

Introduce additional field d3_delay in struct pci_dev and use it to
store the value of the device's D0->D3 delay, in miliseconds.  Make
the PCI PM core code use the per-device d3_delay unless
pci_pm_d3_delay is greater (in which case the latter is used).
[This also allows the driver to specify d3_delay shorter than the
 10 ms required by the PCI standard if the device is known to be able
 to handle that.]

Make the sky2 driver set d3_delay to 150 for devices handled by it.

Fixes http://bugzilla.kernel.org/show_bug.cgi?id=14730 which is a
listed regression from 2.6.30.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

After commit b9c3b266 ("PCI: support
device-specific reset methods") the kernel build is broken if
CONFIG_PCI_QUIRKS is unset.

Fix this by moving pci_dev_specific_reset() to drivers/pci/quirks.c and
providing an empty replacement for !CONFIG_PCI_QUIRKS builds.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The cardbus code creates PCI devices without ever going through the
necessary fixup bits and pieces that normal PCI devices go through.

There's in fact a commented out call to pcibios_fixup_bus() in there,
it's commented because ... it doesn't work.

I could make pcibios_fixup_bus() do the right thing on powerpc easily
but I felt it cleaner instead to provide a specific hook pci_fixup_cardbus
for which a weak empty implementation is provided by the PCI core.

This fixes cardbus on powerbooks and probably all other PowerPC
platforms which was broken completely for ever on some platforms and
since 2.6.31 on others such as PowerBooks when we made the DMA ops
mandatory (since those are setup by the fixups).
Acked-by: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Changing occurrences of variants of PCI-X and PCIe to the PCI-SIG
terms listed in the "Trademark and Logo Usage Guidelines".
http://www.pcisig.com/developers/procedures/logos/Trademark_and_Logo_Usage_Guidelines_updated_112206.pdf

Patch is limited to drivers/pci/ and changes concern comments only.
Signed-off-by: NStefan Assmann <sassmann@redhat.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Add a new type of quirk for resetting devices at pci_dev_reset time.
This is necessary to handle device with nonstandard reset procedures,
especially useful for guest drivers.
Signed-off-by: NYu Zhao <yu.zhao@intel.com>
Signed-off-by: NDexuan Cui <dexuan.cui@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Remove a stray space in pci_save_state().
Signed-off-by: NKleber Sacilotto de Souza <klebers@linux.vnet.ibm.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Commit ae21ee65 "PCI: acs p2p upsteram
forwarding enabling" doesn't actually enable ACS.

Add a function to pci core to allow an IOMMU to request that ACS
be enabled.  The existing mechanism of using iommu_found() in the pci
core to know when ACS should be enabled doesn't actually work due to
initialization order;  iommu has only been detected not initialized.

Have Intel and AMD IOMMUs request ACS, and Xen does as well during early
init of dom0.

Cc: Allen Kay <allen.m.kay@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The pcie_flr routine writes the device control register with the FLR bit
set clearing all other fields for the FLR duration. Among other fields,
the Max_Payload_Size is also cleared which can cause errors if there are
transactions lurking in the HW pipeline. The patch replaces the blank
write with read-modify-write of the control register keeping the other
fields intact.
Signed-off-by: NShmulik Ravid <shmulikr@broadcom.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This allows us to find out what DMA mask is used for each PCI device at boot
time; useful for debugging.

After the patch:
ehci_hcd 0000:00:02.1: using 31bit consistent DMA mask
e1000 0000:0b:01.0: using 64bit DMA mask
e1000 0000:0b:01.0: using 64bit consistent DMA mask
e1000e 0000:04:00.0: using 64bit DMA mask
e1000e 0000:04:00.0: using 64bit consistent DMA mask
ixgb 0000:0c:01.0: using 64bit DMA mask
ixgb 0000:0c:01.0: using 64bit consistent DMA mask
aacraid 0000:86:00.0: using 32bit DMA mask
aacraid 0000:86:00.0: using 32bit consistent DMA mask
aacraid 0000:86:00.0: using 64bit DMA mask
aacraid 0000:86:00.0: using 64bit consistent DMA mask
qla2xxx 0000:0c:02.0: using 64bit consistent DMA mask
qla2xxx 0000:0c:02.1: using 64bit consistent DMA mask
lpfc 0000:06:00.0: using 64bit DMA mask
lpfc 0000:06:00.1: using 64bit DMA mask
pata_amd 0000:00:06.0: using 32bit DMA mask
pata_amd 0000:00:06.0: using 32bit consistent DMA mask
mptsas 0000:0c:04.0: using 64bit DMA mask
mptsas 0000:0c:04.0: using 64bit consistent DMA mask

forcedeth 0000:00:08.0: using 39bit DMA mask
forcedeth 0000:00:08.0: using 39bit consistent DMA mask
niu 0000:02:00.0: using 44bit DMA mask
niu 0000:02:00.0: using 44bit consistent DMA mask
sata_nv 0000:00:05.0: using 32bit DMA mask
sata_nv 0000:00:05.0: using 32bit consistent DMA mask
ib_mthca 0000:03:00.0: using 64bit DMA mask
ib_mthca 0000:03:00.0: using 64bit consistent DMA mask
Reviewed-by: NGrant Grundler <grundler@google.com>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Change for PCI core to use pci_is_pcie() instead of checking
pci_dev->is_pcie.
Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Use pcie_cap() instead of pci_find_capability() to get PCIe capability
offset in PCI core code. This avoids unnecessary search in PCI
configuration space.
Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

I'm not entirely sure it needs to go into 32, but it's probably the right
thing to do. Another way of explaining the patch is:

 - we currently pick the _first_ exactly matching bus resource entry, but
   the _last_ inexactly matching one. Normally first/last shouldn't
   matter, but bus resource entries aren't actually all created equal: in
   a transparent bus, the last resources will be the parent resources,
   which we should generally try to avoid unless we have no choice. So
   "first matching" is the thing we should always aim for.

 - the patch is a bit bigger than it needs to be, because I simplified the
   logic at the same time. It used to be a fairly incomprehensible

	if ((res->flags & IORESOURCE_PREFETCH) && !(r->flags & IORESOURCE_PREFETCH))
		best = r;       /* Approximating prefetchable by non-prefetchable */

   and technically, all the patch did was to make that complex choice be
   even more complex (it basically added a "&& !best" to say that if we
   already gound a non-prefetchable window for the prefetchable resource,
   then we won't override an earlier one with that later one: remember
   "first matching").

 - So instead of that complex one with three separate conditionals in one,
   I split it up a bit, and am taking advantage of the fact that we
   already handled the exact case, so if 'res->flags' has the PREFETCH
   bit, then we already know that 'r->flags' will _not_ have it. So the
   simplified code drops the redundant test, and does the new '!best' test
   separately. It also uses 'continue' as a way to ignore the bus
   resource we know doesn't work (ie a prefetchable bus resource is _not_
   acceptable for anything but an exact match), so it turns into:

	/* We can't insert a non-prefetch resource inside a prefetchable parent .. */
	if (r->flags & IORESOURCE_PREFETCH)
		continue;
	/* .. but we can put a prefetchable resource inside a non-prefetchable one */
	if (!best)
		best = r;

   instead. With the comments, it's now six lines instead of two, but it's
   conceptually simpler, and I _could_ have written it as two lines:

	if ((res->flags & IORESOURCE_PREFETCH) && !best)
		best = r;	/* Approximating prefetchable by non-prefetchable */

   but I thought that was too damn subtle.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

SPIN_LOCK_UNLOCKED is deprecated. Use DEFINE_SPINLOCK instead.

Make the lock static while at it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This makes PCI resource management messages more consistent and adds a few
new messages to aid debugging.

Whenever we assign resources to a device, update a BAR, or change a
bridge aperture, it's worth noting it.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Messages about PME# being supported and enabled/disabled are probably
useful for debug, but maybe don't need to be on the console.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Jesse accidentally applied v1 [1] of the patchset instead of v2 [2].  This
is the diff between v1 and v2.

The changes in this patch are:
    - tidied vsprintf stack buffer to shrink and compute size more
      accurately
    - use %pR for decoding and %pr for "raw" (with type and flags) instead
      of adding %pRt and %pRf

[1] http://lkml.org/lkml/2009/10/6/491
[2] http://lkml.org/lkml/2009/10/13/441Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Note: dom0 checking in v4 has been separated out into 2/2.

This patch enables P2P upstream forwarding in ACS capable PCIe switches.
It solves two potential problems in virtualization environment where a PCIe
device is assigned to a guest domain using a HW iommu such as VT-d:

1) Unintentional failure caused by guest physical address programmed
   into the device's DMA that happens to match the memory address range
   of other downstream ports in the same PCIe switch.  This causes the PCI
   transaction to go to the matching downstream port instead of go to the
   root complex to get translated by VT-d as it should be.

2) Malicious guest software intentionally attacks another downstream
   PCIe device by programming the DMA address into the assigned device
   that matches memory address range of the downstream PCIe port.

We are in process of implementing device filtering software in KVM/XEN
management software to allow device assignment of PCIe devices behind a PCIe
switch only if it has ACS capability and with the P2P upstream forwarding bits
enabled.  This patch is intended to work for both KVM and Xen environments.
Signed-off-by: NAllen Kay <allen.m.kay@intel.com>
Reviewed-by: NMathew Wilcox <willy@linux.intel.com>
Reviewed-by: NChris Wright <chris@sous-sol.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This uses %pRt to print additional resource information (type, size,
prefetchability, etc.) consistently.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

pci_dfl_cache_line_size is marked as __initdata but referenced by
pci_init() which is __devinit.  Make it __devinitdata instead of
__initdata.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

For non hotplug PCI devices, the system firmware usually configures
CLS correctly.  For pccard devices system firmware can't do it and
Linux PCI layer doesn't do it either.  Unfortunately this leads to
poor performance for certain devices (sata_sil).  Unless MWI, which
requires separate configuration, is to be used, CLS doesn't affect
correctness, so the configuration should be harmless.

This patch makes pci_set_cacheline_size() always built and export it
and make pccard call it during attach.

Please note that some other PCI hotplug drivers (shpchp and pciehp)
also configure CLS on hotplug.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Daniel Ritz <daniel.ritz@gmx.ch>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Greg KH <greg@kroah.com>
Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Cc: Axel Birndt <towerlexa@gmx.de>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

sparc64 is now the only user of PCI_CACHE_LINE_BYTES.  Drop it and set
pci_dfl_cache_line_size from pcibios_init() instead and drop
PCI_CACHE_LINE_BYTES handling from generic pci code.

Orignally-From: David Miller <davem@davemloft.net>
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Till now, CLS has been determined either by arch code or as
L1_CACHE_BYTES.  Only x86 and ia64 set CLS explicitly and x86 doesn't
always get it right.  On most configurations, the chance is that
firmware configures the correct value during boot.

This patch makes pci_init() determine CLS by looking at what firmware
has configured.  It scans all devices and if all non-zero values
agree, the value is used.  If none is configured or there is a
disagreement, pci_dfl_cache_line_size is used.  arch can set the dfl
value (via PCI_CACHE_LINE_BYTES or pci_dfl_cache_line_size) or
override the actual one.

ia64, x86 and sparc64 updated to set the default cls instead of the
actual one.

While at it, declare pci_cache_line_size and pci_dfl_cache_line_size
in pci.h and drop private declarations from arch code.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NDavid Miller <davem@davemloft.net>
Acked-by: NGreg KH <gregkh@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This function may have done more in the past, but all it does now is
apply the PCI_FIXUP_FINAL quirks. So name it sensibly and put it where
it belongs.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Fix kernel-doc notation (& warnings) in pci/pci.c.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

After attempting to change the power state of a PCI device
pci_raw_set_power_state() doesn't check if the value it wrote into
the device's PCI_PM_CTRL register has been stored in there, but
unconditionally modifies the device's current_state field to reflect
the change.  This may cause problems to happen if the power state of
the device hasn't been changed in fact, because it will make the PCI
PM core make a wrong assumption.

To prevent such situations from happening modify
pci_raw_set_power_state() so that it reads the device's PCI_PM_CTRL
register after writing into it and uses the value read from the
register to update the device's current_state field.  Also make it
print a message saying that the device refused to change its power
state as requested (returning an error code in such cases would cause
suspend regressions to appear on some systems, where device drivers'
suspend routines return error codes if pci_set_power_state() fails).
Reviewed-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Some PCI devices fail if their standard configuration registers are
restored twice in a row.  Prevent this from happening by making
pci_restore_state() clear the saved_state flag of the device right
after the device's standard configuration registers have been
populated with the previously saved values.

Simplify PCI PM callbacks by removing the direct clearing of
state_saved from them, as it shouldn't be necessary any more (except
in pci_pm_thaw(), where it has to be cleared, so that the values saved
during the "freeze" phase of hibernation are not used later by mistake).
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Introduce a new PCI device flag, wakeup_prepared, to prevent PCI
wake-up preparation code from being executed twice in a row for the
same device and for the same purpose.
Reviewed-by: NMatthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Rework the PCI wake-up code so that it's easier to read without
changing the functionality.
Reviewed-by: NMatthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

In general a BIOS may goof or we may hotplug in a hotplug controller.
In either case the kernel needs to reserve resources for plugging
in more devices in the future instead of creating a minimal resource
assignment.

We already do this for cardbus bridges I am just adding a variant
for pcie bridges.

v2: Make testing for pcie hotplug bridges based on a flag.

    So far we only set the flag for pcie but a header_quirk
    could easily be added for the non-standard pci hotplug
    bridges.
Signed-off-by: NEric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Background:
Graphic devices are accessed through ranges in I/O or memory space. While most
modern devices allow relocation of such ranges, some "Legacy" VGA devices
implemented on PCI will typically have the same "hard-decoded" addresses as
they did on ISA. For more details see "PCI Bus Binding to IEEE Std 1275-1994
Standard for Boot (Initialization Configuration) Firmware Revision 2.1"
Section 7, Legacy Devices.

The Resource Access Control (RAC) module inside the X server currently does
the task of arbitration when more than one legacy device co-exists on the same
machine. But the problem happens when these devices are trying to be accessed
by different userspace clients (e.g. two server in parallel). Their address
assignments conflict. Therefore an arbitration scheme _outside_ of the X
server is needed to control the sharing of these resources. This document
introduces the operation of the VGA arbiter implemented for Linux kernel.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NTiago Vignatti <tiago.vignatti@nokia.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Some devices allow an individual function to be reset without affecting
other functions in the same device: that's what pci_reset_function does.
For devices that have this support, expose reset attribite in sysfs.

This is useful e.g. for virtualization, where a qemu userspace
process wants to reset the device when the guest is reset,
to emulate machine reboot as closely as possible.
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Without the check, the config space may be filled with zeros. Though
the driver should try to avoid call restoring before saving, but the
pci layer also should check this.

Also removes the existing check in pci_restore_standard_config, since
it's superfluous with the new check in restore_state.
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NAlek Du <alek.du@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

For many purposes, including interrupt-swizzling, devices with ARI
enabled behave as if they have one device (number 0) and 256 functions.
This probably hasn't bitten us in practice because all ARI devices I've
seen are also IOV devices, and IOV devices are required to use MSI.
This isn't guaranteed, and there are legitimate reasons to use ARI
without IOV, and hence potentially use pin-based interrupts.
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

For devices attached to the root bus, we can't trigger Secondary Bus
Reset because there is no bridge device associated with the bus. So
need to check bus->self again NULL first before using it.
Reviewed-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NYu Zhao <yu.zhao@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Other functions use type bool, so use that for pci_enable_wake as well.
Signed-off-by: NFrans Pop <elendil@planet.nl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

If a PCI device is not power-manageable either by the platform, or
with the help of the native PCI PM interface, pci_target_state() will
return either PCI_D3hot, or PCI_POWER_ERROR for it, depending on
whether or not the device is configured to wake up the system.  Alas,
none of these return values is correct, because each of them causes
pci_prepare_to_sleep() to return error code, although it should
complete successfully in such a case.

Fix this problem by making pci_target_state() always return PCI_D0
for devices that cannot be power managed.

Cc: stable@kernel.org
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

PCI-to-PCI Bridge 1.2 specifies that the Secondary Bus Reset bit can
force the assertion of RST# on the secondary interface, which can be
used to reset all devices including subordinates under this bus. This
can be used to reset a function if this function is the only device
under this bus.
Reviewed-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NYu Zhao <yu.zhao@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>