Requested by Greg KH to fix a race condition in the creating of PCI bus
cpuaffinity files.
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
After remove the device from /sys, we have to rescan all or
find out the bridge and access /sys../device/rescan there.
this patch add /sys/.../pci_bus/.../rescan. So user can rescan more easy.
that is more clean and easy to understand.
like after remove 0000:c4:00.0, you can rescan 0000:c4 directly.
-v2: According to Jesse, use function instead of exposing attr, so could hide
#ifdef in header file.
also add code to remove rescan file in remove path.
-v3: GregKH pointed out that we should use dev_attrs to avoid racing.
So add pcibus_attrs and make it to be member of pcibus_attrs.
-v4: Change name to pcibus_dev_attrs according to GregKH
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
pci_add_new_bus() calls pci_alloc_child_bus() which calls pci_alloc_bus()
that allocates memory dynamically with kzalloc(). The return value of
kzalloc() is the pointer that's eventually returned from
pci_add_new_bus(), so since kzalloc() can fail and return NULL so can
pci_add_new_bus(). Thus we may end up dereferencing a NULL pointer in
drivers/pci/probe.c::pci_scan_bridge(). Seems to me we should test for
this and bail out if it happens rather than crashing.
Also removed some trailing whitespace that bugged me while looking at
this.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Previously we had to have CONFIG_PCI_DEBUG=y or CONFIG_DYNAMIC_DEBUG=y
to turn on this printk, but I think the IDs are valuable enough that it's
worth putting them in the log always.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
It is a known issue that mmio decoding shall be disabled while doing PCI
bar sizing. Host bridge and other devices (PCI PIC) shall be excluded for
certain platforms. This patch mainly comes from Mathew Willcox's
patch in http://kerneltrap.org/mailarchive/linux-kernel/2007/9/13/258969.
A new flag bit "mmio_alway_on" is added to pci_dev with the intention that
devices with their mmio decoding cannot be disabled during BAR sizing shall
have this bit set, preferrablly in their quirks.
Without this patch, Intel Moorestown platform graphics unit will be
corrupted during bar sizing activities.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Now, a dedicated HEST tabling parsing code is used for PCIE AER
firmware_first setup. It is rebased on general HEST tabling parsing
code of APEI. The firmware_first setup code is moved from PCI core to
AER driver too, because it is only AER related.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Len Brown <len.brown@intel.com>
This reverts c519a5a7da. That change added a warning about devices that
didn't respond correctly when sizing BARs, which helped diagnose broken
devices. But the test wasn't specific enough, so it also complained about
working devices with zero-size BARs, e.g.,
https://bugzilla.kernel.org/show_bug.cgi?id=15822
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
If we can tell that a device isn't working correctly, we should tell
the user to make debugging easier. Otherwise, it can take a lot of
work to determine whether the problem is in the driver, PCMCIA, PCI,
hardware, etc., as in http://bugzilla.kernel.org/show_bug.cgi?id=12006
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
No functional change; this just tweaks the changes from 349e1823a405
so the new printks for disabled PCI-to-PCI bridge windows match the
ones for the enabled windows.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
CC: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
No functional change; just add names for the primary/secondary/subordinate
bus numbers read from config space rather than repeatedly masking/shifting.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Set power.async_suspend for all PCI devices and PCIe port services,
so that they can be suspended and resumed in parallel with other
devices they don't depend on in a known way (i.e. devices which are
not their parents or children).
This only affects the "regular" suspend and resume stages, which
means in particular that the restoration of the PCI devices' standard
configuration registers during resume will still be carried out
synchronously (at the "early" resume stage).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Previously we used a table of size PCI_BUS_NUM_RESOURCES (16) for resources
forwarded to a bus by its upstream bridge. We've increased this size
several times when the table overflowed.
But there's no good limit on the number of resources because host bridges
and subtractive decode bridges can forward any number of ranges to their
secondary buses.
This patch reduces the table to only PCI_BRIDGE_RESOURCE_NUM (4) entries,
which corresponds to the number of windows a PCI-to-PCI (3) or CardBus (4)
bridge can positively decode. Any additional resources, e.g., PCI host
bridge windows or subtractively-decoded regions, are kept in a list.
I'd prefer a single list rather than this split table/list approach, but
that requires simultaneous changes to every architecture. This approach
only requires immediate changes where we set up (a) host bridges with more
than four windows and (b) subtractive-decode P2P bridges, and we can
incrementally change other architectures to use the list.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
No functional change; this fills in the bus subtractive decode resources
after reading the bridge window information rather than before. Also,
print out the subtractive decode resources as we already do for the
positive decode windows.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
No functional change; this breaks up pci_read_bridge_bases() into separate
pieces for the I/O, memory, and prefetchable memory windows, similar to how
Yinghai recently split up pci_setup_bridge() in 68e84ff3bdc.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
We already track unassigned resources in struct resource, and this
prevents us from overwriting resource flags and info in the unassigned
case.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Yinghai pointed out that the new pci_scan_slot() crashes when called
on an ARI-capable slot that is empty. Fix this by exiting early from
pci_scan_slot if there is no device in the slot.
Also make next_ari_func() robust against devices not existing in case
the ARI capability is corrupt. ARI also requires that the devices be
listed in order, so if we find a function listed that is out of order,
stop scanning to prevent loops.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Take advantage of some gaps in the table to fit in support for AGP speeds.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Both PCIe and PCI-X bridges report their secondary bus speed in their
respective capabilities.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Move the max_bus_speed and cur_bus_speed into the pci_bus. Expose the
values through the PCI slot driver instead of the hotplug slot driver.
Update all the hotplug drivers to use the pci_bus instead of their own
data structures.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The Alternate Routing-ID Interpretation capability allows a single device
to have up to 256 functions. They can be populated sparsely, so the
current technique of scanning every eighth function is not guaranteed
to find them all. By introducing a 'next_fn' function pointer, we can
use the linked list of functions in the ARI capability to scan all the
functions which exist.
We can then speed up the pci_scan_slot by skipping the scan of subsequent
devfns for PCIe devices which are the direct children of Root Ports or
Downstream Ports. These devices are only permitted to implement device
0, unless they are ARI devices, in which case they'll be scanned by the
ARI code above.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
We are missing these when building the pci_dev from scratch off
the Open Firmware device-tree
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Commit ae21ee65e8 "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: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Jesse 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: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
There are a lot of codes that searches PCI express capability offset
in the PCI configuration space using pci_find_capability(). Caching it
in the struct pci_dev will reduce unncecessary search. This patch adds
an additional 'pcie_cap' fields into struct pci_dev, which is
initialized at pci device scan time (in set_pcie_port_type()).
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse 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: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Since we have a struct device, we might as well use dev_printk. Note that
both pr_debug() and dev_dbg() are completely compiled out unless DEBUG or
DYNAMIC_DEBUG is defined.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse 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/2009/10/13/441
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Change to populate the subsystem vendor and subsytem device IDs for
PCI-PCI bridges that implement the PCI Subsystem Vendor ID capability.
Previously bridges left subsystem vendor IDs unpopulated.
Signed-off-by: Gabe Black <gabe.black@ni.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Feedback from Hidetoshi Seto and Kenji Kaneshige incorporated. This
correctly handles PCI-X bridges, PCIe root ports and endpoints, and
prints debug messages when invalid/reserved types are found in the
HEST. PCI devices not in domain/segment 0 are not represented in
HEST, thus will be ignored.
Today, the PCIe Advanced Error Reporting (AER) driver attaches itself
to every PCIe root port for which BIOS reports it should, via ACPI
_OSC.
However, _OSC alone is insufficient for newer BIOSes. Part of ACPI
4.0 is the new APEI (ACPI Platform Error Interfaces) which is a way
for OS and BIOS to handshake over which errors for which components
each will handle. One table in ACPI 4.0 is the Hardware Error Source
Table (HEST), where BIOS can define that errors for certain PCIe
devices (or all devices), should be handled by BIOS ("Firmware First
mode"), rather than be handled by the OS.
Dell PowerEdge 11G server BIOS defines Firmware First mode in HEST, so
that it may manage such errors, log them to the System Event Log, and
possibly take other actions. The aer driver should honor this, and
not attach itself to devices noted as such.
Furthermore, Kenji Kaneshige reminded us to disallow changing the AER
registers when respecting Firmware First mode. Platform firmware is
expected to manage these, and if changes to them are allowed, it could
break that firmware's behavior.
The HEST parsing code may be replaced in the future by a more
feature-rich implementation. This patch provides the minimum needed
to prevent breakage until that implementation is available.
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
When probing for ROM BAR size, we should not change bits 1:10 in this
BAR, because these bits are marked as "reserved for future use" in PCI
spec, so changing them might have side effects.
No such issue for I/O or memory, as there is an implementation note in
PCI spec which explicitly allows writing 0xfffffffff there.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This patch is predicated on Jeremy's patch in include/xen/xen.h. It'll
prevent ACS init unless the platform has both an IOMMU and we're running
as dom0.
Signed-off-by: Allen Kay <allen.m.kay@intel.com>
Signed-off-by: Jesse 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: Allen Kay <allen.m.kay@intel.com>
Reviewed-by: Mathew Wilcox <willy@linux.intel.com>
Reviewed-by: Chris Wright <chris@sous-sol.org>
Signed-off-by: Jesse 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: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse 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: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
We already print it out for pci bridges, so also print it out for pci devices.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This was #define'd as 0 on all platforms, so let's get rid of it.
This change makes pci_scan_slot() slightly easier to read.
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Tony Luck <tony.luck@intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Russell King <linux@arm.linux.org.uk>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Use pci_is_root_bus() in pci_read_bridge_bases() to check if the pci
bus is root, for code consistency.
Reviewed-by: Alex Chiang <achiang@hp.com>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
We should not assign 64bit ranges to PCI devices that only take 32bit
prefetchable addresses.
Try to set IORESOURCE_MEM_64 in 64bit resource of pci_device/pci_bridge
and make the bus resource only have that bit set when all devices under
it support 64bit prefetchable memory. Use that flag to allocate
resources from that range.
Reported-by: Yannick <yannick.roehlly@free.fr>
Reviewed-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The device class may be changed after the fixup, so re-read the class
value from pci_dev when configuring the device. Otherwise some devices
such as JMicron SATA controller won't work.
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Tested-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Commit 30a18d6c3f introduced a new
function to set the PCI bus resources. Unfortunately, neither the
author, nor the committers seemed to know that we already have somewhere
to do that -- pcibios_fixup_bus(). This patch moves the hook (used only
by the K8 code) into x86-specific code where it should have been in the
first place.
Cc: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
pci_rescan_bus was annotated as __devinit, which is wrong,
because it will never be part of device initialization.
Howevever, we can't simply drop the annotation, because then we
get section warnings about calling pci_scan_child_bus (which is
correctly marked as __devinit).
pci_rescan_bus will only get built when CONFIG_HOTPLUG is set,
meaning that __devinit is a nop, so we know that pci_scan_child_bus
has not been freed.
Annotate as __ref to silence modpost.
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
New pci_cfg_space_size() needs invalid pdev->class, put it in the
right place in the pci_setup_device().
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This interface allows the user to force a rescan of all PCI buses
in system, and rediscover devices that have been removed earlier.
pci_bus_attrs implementation from Trent Piepho.
Thanks to Vegard Nossum for discovering locking issues with the
sysfs interface.
Cc: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This API is used by the PCI core to rescan a bus and rediscover
newly added devices.
Over time, it is expected that the various PCI hotplug drivers
will migrate to this interface and away from the old
pci_do_scan_bus() interface.
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
While scanning bridges, we stop our scan if we encounter a bus
that we've seen before, to work around some buggy chipsets. This
is a good idea, but prevents us from fully scanning the PCI bus
at a future time (to find newly hot-added devices, for example).
Change the logic so that we skip _re-adding_ an existing bus
that we've seen before, but also allow the scan to descend to
all child buses.
Now that we're potentially scanning our child buses again, we
also need to be sure not to attempt re-initializing their BARs
so we avoid that.
This patch lays the groundwork to allow the user to issue a
rescan of the PCI bus at any time.
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
pci_scan_slot() has been rewritten to be less complex and will now
return the number of *new* devices found.
Existing callers need not worry because they already assume that
they can't call pci_scan_slot() on an already-scanned slot.
Thus, there is no semantic change for existing callers: returning
newly found devices (this patch) is exactly equal to returning all
found devices (before this patch).
This patch adds some more groundwork to allow us to rescan the
PCI bus during runtime to discover newly added devices.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Reviewed-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
pci_scan_single_device is supposed to add newly discovered
devices to pci_bus->devices, but doesn't check to see if the
device has already been added. This can cause problems if we ever
want to use this interface to rescan the PCI bus.
If the device is already added, just return it.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Move the device setup stuff into pci_setup_device() which will be used
to setup the Virtual Function later.
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
