This adjusts PCI_IOAPIC to be user configurable (possibly as a
module) on x86, since the base architecture code for adding
IO-APICs dynamically isn't there yet (and hence having the code
present everywhere is pretty pointless).

To make this consistent, a MODULE_DEVICE_TABLE() declaration
gets added, the class specifications get corrected (by properly
using PCI_DEVICE_CLASS() intended for purposes like this), and
the probe and remove functions get their sections adjusted.
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/4EDDD71A02000078000659F1@nat28.tlf.novell.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

Previously we claimed device ID 0x7450, regardless of the vendor, which is
clearly wrong.  Now we'll claim that device ID only for AMD.

I suspect this was just a typo in the original code, but it's possible this
change will break shpchp on non-7450 AMD bridges.  If so, we'll have to fix
them as we find them.

Reference: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=638863Reported-by: NRalf Jung <ralfjung-e@gmx.de>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

If the port supports Link speeds greater than 5.0 GT/s, we must wait
for 100 ms after Link training completes before sending configuration
request.
Acked-by: NYinghai Lu <yinghai@kernel.org>
Tested-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

We need to wait for 1000 ms after Data Link Layer Link Active (DLLLA)
bit reads 1b before sending configuration request. Currently pciehp
does this wait after checking Link Training (LT) bit. But we need it
before checking LT bit because LT is still set even after DLLLA bit is
set on some platforms.
Acked-by: NYinghai Lu <yinghai@kernel.org>
Tested-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

During hot plug, board_added will call pciehp_power_on_slot().
But link speed is updated in pciehp_power_on_slot().

We should not update link speed there, because that is too early.

So move the link speed update to pciehp_check_link_status() after making
sure the link has been trained.

-v2: fix compile warning that Kenji found.
Signed-off-by: NYinghai Lu <yinghai.lu@oracle.com>
Reviewed-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Tested-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

These were getting module.h implicitly from device.h but we want
to clean that up, so we fix it here to avoid things like:

pci/slot.c: In function ‘pci_hp_create_module_link’:
pci/slot.c:383: error: ‘module_kset’ undeclared (first use in this function)

Similarly, rpadlpar_core.c is modular, so add module.h to its includes.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

They were implicitly getting it from device.h --> module.h but
we want to clean that up.  So add the minimal header for these
macros.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

There's no other Kconfig symbol that depends on XEN_PCIDEV_FE_DEBUG.
Neither is there anything that uses CONFIG_XEN_PCIDEV_FE_DEBUG.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

This avoids the PCI_PRI question in 'make config' when PCI
is not selected.
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

If the kernel has requested control of the PCIe native hotplug
feature for a given root complex, the acpiphp driver should not try
to handle that root complex and it should leave it to pciehp.
Failing to do so causes problems to happen if acpiphp is loaded
before pciehp on such systems.

To address this issue make find_root_bridges() ignore PCIe root
complexes with PCIe native hotplug enabled and make add_bridge()
return error code if PCIe native hotplug is enabled for the given
root port.  This causes acpiphp to refuse to load if PCIe native
hotplug is enabled for all complexes and to refuse binding to
the root complexes with PCIe native hotplug is enabled.
Acked-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>

Clean-up MPS debug output to make it a single line and aligned, thus
making it more readable for a large number of buses and devices in a
single system.

Suggested by Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NJon Mason <mason@myri.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

When configuring the PCIe settings for "performance", we allow parents
to have a larger Max Payload Size than children and rely on children
Max Read Request Size to not be larger than their own MPS to avoid
having the host bridge generate responses they can't cope with.

However, various drivers in Linux call pci_set_readrq() with arbitrary
values, assuming this to be a simple performance tweak. This breaks
under our "performance" configuration.

Fix that by making sure the value programmed by pcie_set_readrq() is
never larger than the configured MPS for that device.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NJon Mason <mason@myri.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Rework the "performance" MPS option to configure the device MPS with the
smaller of the device MPSS or the bridge MPS (which is assumed to be
properly configured at this point to the largest allowable MPS based on
its parent bus).

Also, rework the MRRS setting to report an inability to set the MRRS to
a valid setting.
Signed-off-by: NJon Mason <mason@myri.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Intel 5000 and 5100 series memory controllers have a known issue if read
completion coalescing is enabled and the PCI-E Maximum Payload Size is
set to 256B.  To work around this issue, disable read completion
coalescing in the memory controller and root complexes.  Unfortunately,
it must always be disabled, even if no 256B MPS devices are present, due
to the possibility of one being hotplugged.

Links to erratas:
http://www.intel.com/content/dam/doc/specification-update/5000-chipset-memory-controller-hub-specification-update.pdf
http://www.intel.com/content/dam/doc/specification-update/5100-memory-controller-hub-chipset-specification-update.pdf

Thanks to Jesse Brandeburg and Ben Hutchings for providing insight into
the problem.
Tested-and-Reported-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NJon Mason <mason@myri.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Devices supporting Process Address Space Identifiers
(PASIDs) can use an IOMMU to access multiple IO address
spaces at the same time. A PCIe device indicates support for
this feature by implementing the PASID capability. This
patch adds support for the capability to the Linux kernel.
Reviewed-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Implement the necessary functions to handle PRI capabilities
on PCIe devices. With PRI devices behind an IOMMU can signal
page fault conditions to software and recover from such
faults.
Reviewed-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This patch makes the ATS functions usable for modules.
They will be used by a module implementing some advanced
AMD IOMMU features.
Reviewed-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

ATS does not depend on IOV support, so move the code into
its own file. This file will also include support for the
PRI and PASID capabilities later.
Also give ATS its own Kconfig variable to allow selecting it
without IOV support.
Reviewed-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The result returned by acpi_dev_run_wake() is always either -EINVAL
or -ENODEV, while obviously it should return 0 on success.  The
problem is that the leftover error variable, that's not really used
in the function, is initialized with -ENODEV and then returned
without modification.

To fix this issue remove the error variable from acpi_dev_run_wake()
and make the function return 0 on success as appropriate.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

I originally submitted a patch to workaround this by pushing all Ejection
Requests and Device Checks onto the kacpi_hotplug queue.

http://marc.info/?l=linux-acpi&m=131678270930105&w=2

The patch is still insufficient in that Bus Checks also need to be added.

Rather than add all events, including non-PCI-hotplug events, to the
hotplug queue, mjg suggested that a better approach would be to modify
the acpiphp driver so only acpiphp events would be added to the
kacpi_hotplug queue.

It's a longer patch, but at least we maintain the benefit of having separate
queues in ACPI.  This, of course, is still only a workaround the problem.
As Bjorn and mjg pointed out, we have to refactor a lot of this code to do
the right thing but at this point it is a better to have this code working.

The acpi core places all events on the kacpi_notify queue.  When the acpiphp
driver is loaded and a PCI card with a PCI-to-PCI bridge is removed the
following call sequence occurs:

cleanup_p2p_bridge()
	    -> cleanup_bridge()
		    -> acpi_remove_notify_handler()
			    -> acpi_os_wait_events_complete()
				    -> flush_workqueue(kacpi_notify_wq)

which is the queue we are currently executing on and the process will hang.

Move all hotplug acpiphp events onto the kacpi_hotplug workqueue.  In
handle_hotplug_event_bridge() and handle_hotplug_event_func() we can simply
push the rest of the work onto the kacpi_hotplug queue and then avoid the
deadlock.
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Cc: mjg@redhat.com
Cc: bhelgaas@google.com
Cc: linux-acpi@vger.kernel.org
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>

Commit 15bed0f2 added a quirk for the e823 Ricoh card reader to lower the
base frequency.  However, the quirk first checks to see if the proprietary
MMC controller is disabled, and returns if so.  On some devices, such as the
Lenovo X220, the MMC controller is already disabled by firmware it seems,
but the frequency change is still needed so sdhci-pci can talk to the cards.
Since the MMC controller is disabled, the frequency fixup was never being run
on these machines.

This moves the e823 check above the MMC controller check so that it always
gets run.

This fixes https://bugzilla.redhat.com/show_bug.cgi?id=722509Signed-off-by: NJosh Boyer <jwboyer@redhat.com>
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>

Using legacy interrupts and TLPs > 256 bytes on the SFC4000 (all
revisions) may cause interrupt messages to be replayed.  In some
systems this results in a non-recoverable MCE.  Early boards using the
SFC4000 set the maximum payload size supported (MPSS) to 1024 bytes
and we should override that.

There are probably other devices with similar issues, so give this
quirk a generic name.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
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>

Change the CONFIG_DMAR to CONFIG_INTEL_IOMMU to be consistent
with the other IOMMU options.

Rename the CONFIG_INTR_REMAP to CONFIG_IRQ_REMAP to match the
irq subsystem name.

And define the CONFIG_DMAR_TABLE for the common ACPI DMAR
routines shared by both CONFIG_INTEL_IOMMU and CONFIG_IRQ_REMAP.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: yinghai@kernel.org
Cc: youquan.song@intel.com
Cc: joerg.roedel@amd.com
Cc: tony.luck@intel.com
Cc: dwmw2@infradead.org
Link: http://lkml.kernel.org/r/20110824001456.558630224@sbsiddha-desk.sc.intel.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

In pcie_find_smpss(), we have the following statement:

 	if (dev->is_hotplug_bridge && (!list_is_singular(&dev->bus->devices) ||
	    dev->bus->self->pcie_type != PCI_EXP_TYPE_ROOT_PORT))

The problem is that at least on my machine, this gets called for the
root complex (virtual P2P bridge), and dev->bus->self is NULL since
the parent bus for this is not itself anchor to a PCI device.

This adds the necessary NULL check.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NJon Mason <mason@myri.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Modifying the Maximum Read Request Size to 0 (value of 128Bytes) has
massive negative ramifications on some devices.  Without knowing which
devices have this issue, do not modify from the default value when
walking the PCI-E bus in pcie_bus_safe mode.  Also, make pcie_bus_safe
the default procedure.
Tested-by: NSven Schnelle <svens@stackframe.org>
Tested-by: NSimon Kirby <sim@hostway.ca>
Tested-by: NStephen M. Cameron <scameron@beardog.cce.hp.com>
Reported-and-tested-by: NEric Dumazet <eric.dumazet@gmail.com>
Reported-and-tested-by: NNiels Ole Salscheider <niels_ole@salscheider-online.de>
References: https://bugzilla.kernel.org/show_bug.cgi?id=42162Signed-off-by: NJon Mason <mason@myri.com>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit b03e7495 ("PCI: Set PCI-E Max Payload Size on fabric")
introduced a potential NULL pointer dereference in calls to
pcie_bus_configure_settings due to attempts to access pci_bus self
variables when the self pointer is NULL.

To correct this, verify that the self pointer in pci_bus is non-NULL
before dereferencing it.
Reported-by: NStanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: NShyam Iyer <shyam_iyer@dell.com>
Signed-off-by: NJon Mason <mason@myri.com>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With Xen changeset 23428 "libxl: Add 'e820_host' option to config file"
the E820 as seen from the host can now be passed into the guest.
This means that a PV guest can now:
 - Use the correct PCI I/O gap. Before these patches, Linux guest would
   boot up and would tell:
   [    0.000000] Allocating PCI resources starting at 40000000 (gap: 40000000:c0000000)
   while in actuality the PCI I/O gap should have been:
   [    0.000000] Allocating PCI resources starting at b0000000 (gap: b0000000:4c000000)

 - The PV domain with PCI devices was limited to 3GB. It now can be booted
   with 4GB, 8GB, or whatever number you want. The PCI devices will now _not_ conflict
   with System RAM. Meaning the drivers can load.

CC: Jesse Barnes <jbarnes@virtuousgeek.org>
CC: linux-pci@vger.kernel.org
CC: stable@kernel.org
[v2: Made the string less broken up. Suggested by Joe Perches]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Fix new kernel-doc warning in pci.c:

  Warning(drivers/pci/pci.c:3259): No description found for parameter 'mps'
  Warning(drivers/pci/pci.c:3259): Excess function parameter 'rq' description in 'pcie_set_mps'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In pcibios_get_phb_of_node(), we will crash while booting if
bus->bridge->parent is NULL.

Check for this case and avoid dereferencing the NULL pointer.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

pcie_bus_configure_settings needs to be exported if the PCI hotplug
driver is being compiled as a module.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NJon Mason <mason@myri.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

a) adjust_resource_sorted() is now called reassign_resource_sorted()
b) nice-to-have is now called optional
c) add_list is now called realloc_list.
Signed-off-by: NRam Pai <linuxram@us.ibm.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Allocate resources to cardbus bridge only after all other genuine
resources requests are satisfied. Dont retry if resource allocation
for cardbus-bridges fail.
Signed-off-by: NRam Pai <linuxram@us.ibm.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

From: Yinghai Lu <yinghai@kernel.org>

Allocate resources to SRIOV BARs only after all other required
resource-requests are satisfied. Dont retry if resource allocation for SRIOV
BARs fail.
Signed-off-by: NRam Pai <linuxram@us.ibm.com>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

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>

git commit c8adf9a3
    "PCI: pre-allocate additional resources to devices only after
	successful allocation of essential resources."

fails to take into consideration the optional-resources needed by children
devices while calculating the optional-resource needed by the bridge.

This can be a problem on some setup. For example, if a hotplug bridge has 8
children hotplug bridges, the bridge should have enough resources to accomodate
the hotplug requirements for each of its children hotplug bridges.  Currently
this is not the case.

This patch fixes the problem.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Reviewed-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>