DEVICE_COUNT_RESOURCE will be bigger than 16 when SRIOV supported is enabled.

Let them pass with int just like pci_enable_resources().
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Save some bytes for device resource array.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

All users of pci_create_bus() have been converted to pci_create_root_bus(),
so remove it.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

I plan to deprecate pci_scan_bus_parented(), so use pci_create_root_bus()
directly instead.  pci_scan_bus() itself will be removed as soon as all
callers are gone, so this is just an interim step.

v2: export pci_scan_bus
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

"Early" and "header" quirks often use incorrect bus resources because they
see the default resources assigned by pci_create_bus(), before the
architecture fixes them up (typically in pcibios_fixup_bus()).  Regions
reserved by these quirks end up with the wrong parents.

Here's the standard path for scanning a PCI root bus:

  pci_scan_bus or pci_scan_bus_parented
    pci_create_bus                     <-- A create with default resources
    pci_scan_child_bus
      pci_scan_slot
        pci_scan_single_device
          pci_scan_device
            pci_setup_device
              pci_fixup_device(early)  <-- B
          pci_device_add
            pci_fixup_device(header)   <-- C
      pcibios_fixup_bus                <-- D fill in correct resources

Early and header quirks at B and C use the default (incorrect) root bus
resources rather than those filled in at D.

This patch adds a new pci_scan_root_bus() function that sets the bus
resources correctly from a supplied list of resources.

I intend to remove pci_scan_bus() and pci_scan_bus_parented() after
fixing all callers.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

pci_create_bus() assigns ioport_resource and iomem_resource as the default
bus resources, i.e., the entire address space.  Architectures fix these
later, typically in pcibios_fixup_bus() or after pci_scan_bus_parented()
returns, but code that runs in the interim sees incorrect resource
information.

This patch adds a new pci_create_root_bus() that sets the bus resources
correctly from a supplied list of resources.

I intend to remove pci_create_bus() after changing all callers.

Based on original patch by Deng-Cheng Zhu.

Reference: http://www.spinics.net/lists/mips/msg41654.html
Reference: https://lkml.org/lkml/2011/8/26/88Signed-off-by: NDeng-Cheng Zhu <dczhu@mips.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

We'd like to supply a list of resources when we create a new PCI bus,
e.g., the root bus under a PCI host bridge.  These are helpers for
constructing that list.

These are exported because the plan is to replace this exported interface:
    pci_scan_bus_parented()
with this one:
    pci_add_resource(resources, ...)
    pci_scan_root_bus(..., resources)
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The 'latency timer' of PCI devices, both Type 0 and Type 1,
is setup in architecture-specific code [see: 'pcibios_set_master()'].
There are two approaches being taken by all the architectures - check
if the 'latency timer' is currently set between 16 and 255 and if not
bring it within bounds, or, do nothing (and then there is the
gratuitously different PA-RISC implementation).

There is nothing architecture-specific about PCI's 'latency timer' so
this patch pulls its setup functionality up into the PCI core by
creating a generic 'pcibios_set_master()' function using the '__weak'
attribute which can be used by all architectures as a default which,
if necessary, can then be over-ridden by architecture-specific code.

No functional change.
Signed-off-by: NMyron Stowe <myron.stowe@redhat.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Currently, pcibios_set_master() is implemented in architecture-
specific code.  There is nothing architecture-specific about PCI's
'latency timer'.

This patch adds a declaration for pcibios_set_master() to PCI's core
in preperation for pulling the function itself up into the core.
Without the addition of this declaration, subsequent patches that
remove inline definitions of pcibios_set_master() would be removing
the only declaration of such.

No functional change.
Signed-off-by: NMyron Stowe <myron.stowe@redhat.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

These new PCI services allow to probe for 2.3-compliant INTx masking
support and then use the feature from PCI interrupt handlers. The
services are properly synchronized with concurrent config space access
via sysfs or on device reset.

This enables generic PCI device drivers like uio_pci_generic or KVM's
device assignment to implement the necessary kernel-side IRQ handling
without any knowledge about device-specific interrupt status and control
registers.
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

pci_block_user_cfg_access was designed for the use case that a single
context, the IPR driver, temporarily delays user space accesses to the
config space via sysfs. This assumption became invalid by the time
pci_dev_reset was added as locking instance. Today, if you run two loops
in parallel that reset the same device via sysfs, you end up with a
kernel BUG as pci_block_user_cfg_access detect the broken assumption.

This reworks the pci_block_user_cfg_access to a sleeping service
pci_cfg_access_lock and an atomic-compatible variant called
pci_cfg_access_trylock. The former not only blocks user space access as
before but also waits if access was already locked. The latter service
just returns false in this case, allowing the caller to resolve the
conflict instead of raising a BUG.

Adaptions of the ipr driver were originally written by Brian King.
Acked-by: NBrian King <brking@linux.vnet.ibm.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This patch adds a per-pci-device subdirectory in sysfs called:
/sys/bus/pci/devices/<device>/msi_irqs

This sub-directory exports the set of msi vectors allocated by a given
pci device, by creating a numbered sub-directory for each vector beneath
msi_irqs.  For each vector various attributes can be exported.
Currently the only attribute is called mode, which tracks the
operational mode of that vector (msi vs. msix)
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This patch adds a per-pci-device subdirectory in sysfs called:
/sys/bus/pci/devices/<device>/msi_irqs

This sub-directory exports the set of msi vectors allocated by a given
pci device, by creating a numbered sub-directory for each vector beneath
msi_irqs.  For each vector various attributes can be exported.
Currently the only attribute is called mode, which tracks the
operational mode of that vector (msi vs. msix)
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The ats and sroiv members of 'struct pci_dev' are required
for the ATS code already, even without IOV support compiled
in. So depend on ATS here. This is fine with PCI_IOV too
because it selects PCI_ATS. Also the prototypes for ATS
need to be available for PCI_ATS.
Reported-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The land of PCI power management is a land of sorrow and ugliness,
especially in the area of signaling events by devices.  There are
devices that set their PME Status bits, but don't really bother
to send a PME message or assert PME#.  There are hardware vendors
who don't connect PME# lines to the system core logic (they know
who they are).  There are PCI Express Root Ports that don't bother
to trigger interrupts when they receive PME messages from the devices
below.  There are ACPI BIOSes that forget to provide _PRW methods for
devices capable of signaling wakeup.  Finally, there are BIOSes that
do provide _PRW methods for such devices, but then don't bother to
call Notify() for those devices from the corresponding _Lxx/_Exx
GPE-handling methods.  In all of these cases the kernel doesn't have
a chance to receive a proper notification that it should wake up a
device, so devices stay in low-power states forever.  Worse yet, in
some cases they continuously send PME Messages that are silently
ignored, because the kernel simply doesn't know that it should clear
the device's PME Status bit.

This problem was first observed for "parallel" (non-Express) PCI
devices on add-on cards and Matthew Garrett addressed it by adding
code that polls PME Status bits of such devices, if they are enabled
to signal PME, to the kernel.  Recently, however, it has turned out
that PCI Express devices are also affected by this issue and that it
is not limited to add-on devices, so it seems necessary to extend
the PME polling to all PCI devices, including PCI Express and planar
ones.  Still, it would be wasteful to poll the PME Status bits of
devices that are known to receive proper PME notifications, so make
the kernel (1) poll the PME Status bits of all PCI and PCIe devices
enabled to signal PME and (2) disable the PME Status polling for
devices for which correct PME notifications are received.
Tested-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The "powernv" platform of the powerpc architecture needs to assign PCI
resources using a specific algorithm to fit some HW constraints of
the IBM "IODA" architecture (related to the ability to create error
handling domains that encompass specific segments of MMIO space).

For doing so, it wants to call pci_setup_bridge() from architecture
specific resource management in order to configure bridges after all
resources have been assigned. So make it non-static.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Add the ability to disable PCI-E MPS turning and using the BIOS
configured MPS defaults.  Due to the number of issues recently
discovered on some x86 chipsets, make this the default behavior.

Also, add the option for peer to peer DMA MPS configuration.  Peer to
peer DMA is outside the scope of this patch, but MPS configuration could
prevent it from working by having the MPS on one root port different
than the MPS on another.  To work around this, simply make the system
wide MPS the smallest possible value (128B).
Signed-off-by: NJon Mason <mason@myri.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Device drivers that create and destroy SR-IOV virtual functions via
calls to pci_enable_sriov() and pci_disable_sriov can cause catastrophic
failures if they attempt to destroy VFs while they are assigned to
guest virtual machines.  By adding a flag for use by the KVM module
to indicate that a device is assigned a device driver can check that
flag and avoid destroying VFs while they are assigned and avoid system
failures.

CC: Ian Campbell <ijc@hellion.org.uk>
CC: Konrad Wilk <konrad.wilk@oracle.com>
Signed-off-by: NGreg Rose <gregory.v.rose@intel.com>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Currently pci-bridges are allocated enough resources to satisfy their immediate
requirements.  Any additional resource-requests fail if additional free space,
contiguous to the one already allocated, is not available. This behavior is not
reasonable since sufficient contiguous resources, that can satisfy the request,
are available at a different location.

This patch provides the ability to expand and relocate a allocated resource.

	v2: Changelog: Fixed size calculation in pci_reassign_resource()
	v3: Changelog : Split this patch. The resource.c changes are already
			upstream. All the pci driver changes are in here.
Signed-off-by: NRam Pai <linuxram@us.ibm.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

On a given PCI-E fabric, each device, bridge, and root port can have a
different PCI-E maximum payload size.  There is a sizable performance
boost for having the largest possible maximum payload size on each PCI-E
device.  However, if improperly configured, fatal bus errors can occur.
Thus, it is important to ensure that PCI-E payloads sends by a device
are never larger than the MPS setting of all devices on the way to the
destination.

This can be achieved two ways:

- A conservative approach is to use the smallest common denominator of
  the entire tree below a root complex for every device on that fabric.

This means for example that having a 128 bytes MPS USB controller on one
leg of a switch will dramatically reduce performances of a video card or
10GE adapter on another leg of that same switch.

It also means that any hierarchy supporting hotplug slots (including
expresscard or thunderbolt I suppose, dbl check that) will have to be
entirely clamped to 128 bytes since we cannot predict what will be
plugged into those slots, and we cannot change the MPS on a "live"
system.

- A more optimal way is possible, if it falls within a couple of
  constraints:
* The top-level host bridge will never generate packets larger than the
  smallest TLP (or if it can be controlled independently from its MPS at
  least)
* The device will never generate packets larger than MPS (which can be
  configured via MRRS)
* No support of direct PCI-E <-> PCI-E transfers between devices without
  some additional code to specifically deal with that case

Then we can use an approach that basically ignores downstream requests
and focuses exclusively on upstream requests. In that case, all we need
to care about is that a device MPS is no larger than its parent MPS,
which allows us to keep all switches/bridges to the max MPS supported by
their parent and eventually the PHB.

In this case, your USB controller would no longer "starve" your 10GE
Ethernet and your hotplug slots won't affect your global MPS.
Additionally, the hotplugged devices themselves can be configured to a
larger MPS up to the value configured in the hotplug bridge.

To choose between the two available options, two PCI kernel boot args
have been added to the PCI calls.  "pcie_bus_safe" will provide the
former behavior, while "pcie_bus_perf" will perform the latter behavior.
By default, the latter behavior is used.

NOTE: due to the location of the enablement, each arch will need to add
calls to this function.  This patch only enables x86.

This patch includes a number of changes recommended by Benjamin
Herrenschmidt.

Tested-by: Jordan_Hargrave@dell.com
Signed-off-by: NJon Mason <mason@myri.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: NArun Sharma <asharma@fb.com>
Reviewed-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Aside of the usual motivation for constification,  this function has a
history of being abused a hook for interrupt and other fixups so I turned
this function const ages ago in the MIPS code but it should be done
treewide.

Due to function pointer passing in varous places a few other functions
had to be constified as well.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
To: Anton Vorontsov <avorontsov@mvista.com>
To: Chris Metcalf <cmetcalf@tilera.com>
To: Colin Cross <ccross@android.com>
Acked-by: N"David S. Miller" <davem@davemloft.net>
To: Eric Miao <eric.y.miao@gmail.com>
To: Erik Gilling <konkers@android.com>
Acked-by: NGuan Xuetao <gxt@mprc.pku.edu.cn>
To: "H. Peter Anvin" <hpa@zytor.com>
To: Imre Kaloz <kaloz@openwrt.org>
To: Ingo Molnar <mingo@redhat.com>
To: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
To: Jesse Barnes <jbarnes@virtuousgeek.org>
To: Krzysztof Halasa <khc@pm.waw.pl>
To: Lennert Buytenhek <kernel@wantstofly.org>
To: Matt Turner <mattst88@gmail.com>
To: Nicolas Pitre <nico@fluxnic.net>
To: Olof Johansson <olof@lixom.net>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
To: Richard Henderson <rth@twiddle.net>
To: Russell King <linux@arm.linux.org.uk>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-pci@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

'pci_obff_signal_type' is passed between drivers and the kernel API.
This patch explicitly assigns values to the enumeration type's constants
which aids in detecting any future changes or additions that would break
the kernel's ABI.

No functional change.
Signed-off-by: NMyron Stowe <myron.stowe@redhat.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This should ease finding similarities with different platforms,
with the intention of solving problems once in a generic framework
which everyone can use.

Note: to move intel-iommu.c, the declaration of pci_find_upstream_pcie_bridge()
has to move from drivers/pci/pci.h to include/linux/pci.h. This is handled
in this patch, too.

As suggested, also drop DMAR's EXPERIMENTAL tag while we're at it.

Compile-tested on x86_64.
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

The generic code always get the device-node in the right place now
so a single implementation will work for all archs
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NMichal Simek <monstr@monstr.eu>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>

All archs do more or less the same thing now, move it into
a single generic place.

I chose pci.h rather than of_pci.h to avoid having to change
all call-sites to include the later.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NMichal Simek <monstr@monstr.eu>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>

powerpc has two different ways of matching PCI devices to their
corresponding OF node (if any) for historical reasons. The ppc64 one
does a scan looking for matching bus/dev/fn, while the ppc32 one does a
scan looking only for matching dev/fn on each level in order to be
agnostic to busses being renumbered (which Linux does on some
platforms).

This removes both and instead moves the matching code to the PCI core
itself. It's the most logical place to do it: when a pci_dev is created,
we know the parent and thus can do a single level scan for the matching
device_node (if any).

The benefit is that all archs now get the matching for free. There's one
hook the arch might want to provide to match a PHB bus to its device
node. A default weak implementation is provided that looks for the
parent device device node, but it's not entirely reliable on powerpc for
various reasons so powerpc provides its own.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NMichal Simek <monstr@monstr.eu>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>

For KVM device assignment, we'd like to save off the state of a device
prior to passing it to the guest and restore it later.  We also want
to allow pci_reset_funciton() to be called while the device is owned
by the guest.  This however overwrites and invalidates the struct pci_dev
buffers, so we can't just manually call save and restore.  Add generic
interfaces for the saved state to be stored and reloaded back into
struct pci_dev at a later time.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This will allow us to store and load it later.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Latency tolerance reporting allows devices to send messages to the root
complex indicating their latency tolerance for snooped & unsnooped
memory transactions.  Add support for enabling & disabling this
feature, along with a routine to set the max latencies a device should
send upstream.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

OBFF (optimized buffer flush/fill), where supported, can help improve
energy efficiency by giving devices information about when interrupts
and other activity will have a reduced power impact.  It requires
support from both the device and system (i.e. not only does the device
need to respond to OBFF messages, but the platform must be capable of
generating and routing them to the end point).
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Add support to allow drivers to enable/disable ID-based ordering.  Where
supported, ID-based ordering can significantly improve the latency of
individual requests by preventing them from queueing up behind unrelated
traffic.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

So in a lot of modern systems, a GPU will always be below a parent bridge that won't share with any other GPUs. This means VGA arbitration on those GPUs can be controlled by using the bridge routing instead of io/mem decodes.

The problem is locating which GPUs share which upstream bridges. This patch attempts to identify all the GPUs which can be controlled via bridges, and ones that can't. This patch endeavours to work out the bridge sharing semantics.

When disabling GPUs via a bridge, it doesn't do irq callbacks or touch the io/mem decodes for the gpu.
Signed-off-by: NDave Airlie <airlied@redhat.com>

We need to distinguish the situation in which ASPM support is
disabled from the command line or through .config from the situation
in which it is disabled, because the hardware or BIOS can't handle
it.  In the former case we should not report ASPM support to the BIOS
through ACPI _OSC, but in the latter case we should do that.

Introduce pcie_aspm_support_enabled() that can be used by
acpi_pci_root_add() to determine whether or not it should report ASPM
support to the BIOS through _OSC.

Cc: stable@kernel.org
References: https://bugzilla.kernel.org/show_bug.cgi?id=29722
References: https://bugzilla.kernel.org/show_bug.cgi?id=20232Reported-and-tested-by: NOrtwin Glück <odi@odi.ch>
Reviewed-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Tested-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This patch adds code to verify the checksum stored in the "RV" info
keyword of the RODATA VPD section.
Signed-off-by: NMatt Carlson <mcarlson@broadcom.com>
Reviewed-by: NMichael Chan <mchan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When CONFIG_PCI is not enabled, tlan.c has a build error:
drivers/net/tlan.c:503: error: implicit declaration of function 'pci_wake_from_d3'

so add an inline function stub for this function to pci.h when
PCI is not enabled, similar to other stubbed PCI functions.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NSakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The compilation of drivers/acpi/pci_root.c fails if
CONFIG_PCIEPORTBUS is unset.  Fix the problem.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After recent changes related to wakeup events pm_wakeup_event()
automatically checks if the given device is configured to signal wakeup,
so pci_wakeup_event() may be a static inline function calling
pm_wakeup_event() directly.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Move the evaluation of acpi_pci_osc_control_set() (to request control of
PCI Express native features) into acpi_pci_root_add() to avoid calling
it many times for the same root complex with the same arguments.
Additionally, check if all of the requisite _OSC support bits are set
before calling acpi_pci_osc_control_set() for a given root complex.

References: https://bugzilla.kernel.org/show_bug.cgi?id=20232Reported-by: NOzan Caglayan <ozan@pardus.org.tr>
Tested-by: NOzan Caglayan <ozan@pardus.org.tr>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

pci_restore_state only ever returns 0, thus there is no benefit in
having it return any value.  Also, a large majority of the callers do
not check the return code of pci_restore_state.  Make the
pci_restore_state a void return and avoid the overhead.
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NJon Mason <jon.mason@exar.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>