* pci/host-hv:
PCI: hv: Allocate physically contiguous hypercall params buffer
PCI: hv: Delete the device earlier from hbus->children for hot-remove
PCI: hv: Fix hv_pci_remove() for hot-remove
PCI: hv: Use the correct buffer size in new_pcichild_device()
PCI: hv: Make unnecessarily global IRQ masking functions static
* pci/host-altera:
PCI: altera: Remove redundant error message in altera_pcie_parse_dt()
PCI: altera: Use builtin_platform_driver() to simplify the code
* pci/virtualization:
PCI: Add comments about ROM BAR updating
PCI: Decouple IORESOURCE_ROM_ENABLE and PCI_ROM_ADDRESS_ENABLE
PCI: Remove pci_resource_bar() and pci_iov_resource_bar()
PCI: Don't update VF BARs while VF memory space is enabled
PCI: Separate VF BAR updates from standard BAR updates
PCI: Update BARs using property bits appropriate for type
PCI: Ignore BAR updates on virtual functions
PCI: Do any VF BAR updates before enabling the BARs
PCI: Support INTx masking on ConnectX-4 with firmware x.14.1100+
PCI: Convert Mellanox broken INTx quirks to be for listed devices only
PCI: Convert broken INTx masking quirks from HEADER to FINAL
net/mlx4_core: Use device ID defines
PCI: Add Mellanox device IDs
* pci/pm:
x86/platform/intel-mid: Constify mid_pci_platform_pm
PCI: pciehp: Add runtime PM support for PCIe hotplug ports
ACPI / hotplug / PCI: Make device_is_managed_by_native_pciehp() public
ACPI / hotplug / PCI: Use cached copy of PCI_EXP_SLTCAP_HPC bit
PCI: Unfold conditions to block runtime PM on PCIe ports
PCI: Consolidate conditions to allow runtime PM on PCIe ports
PCI: Activate runtime PM on a PCIe port only if it can suspend
PCI: Speed up algorithm in pci_bridge_d3_update()
PCI: Autosense device removal in pci_bridge_d3_update()
PCI: Don't acquire ref on parent in pci_bridge_d3_update()
USB: UHCI: report non-PME wakeup signalling for Intel hardware
PCI: Check for PME in targeted sleep state
There is at least one Chelsio 10Gb card which uses VPD area to store some
non-standard blocks (example below). However pci_vpd_size() returns the
length of the first block only assuming that there can be only one VPD "End
Tag".
Since 4e1a635552 ("vfio/pci: Use kernel VPD access functions"), VFIO
blocks access beyond that offset, which prevents the guest "cxgb3" driver
from probing the device. The host system does not have this problem as its
driver accesses the config space directly without pci_read_vpd().
Add a quirk to override the VPD size to a bigger value. The maximum size
is taken from EEPROMSIZE in drivers/net/ethernet/chelsio/cxgb3/common.h.
We do not read the tag as the cxgb3 driver does as the driver supports
writing to EEPROM/VPD and when it writes, it only checks for 8192 bytes
boundary. The quirk is registered for all devices supported by the cxgb3
driver.
This adds a quirk to the PCI layer (not to the cxgb3 driver) as the cxgb3
driver itself accesses VPD directly and the problem only exists with the
vfio-pci driver (when cxgb3 is not running on the host and may not be even
loaded) which blocks accesses beyond the first block of VPD data. However
vfio-pci itself does not have quirks mechanism so we add it to PCI.
This is the controller:
Ethernet controller [0200]: Chelsio Communications Inc T310 10GbE Single Port Adapter [1425:0030]
This is what I parsed from its VPD:
===
b'\x82*\x0010 Gigabit Ethernet-SR PCI Express Adapter\x90J\x00EC\x07D76809 FN\x0746K'
0000 Large item 42 bytes; name 0x2 Identifier String
b'10 Gigabit Ethernet-SR PCI Express Adapter'
002d Large item 74 bytes; name 0x10
#00 [EC] len=7: b'D76809 '
#0a [FN] len=7: b'46K7897'
#14 [PN] len=7: b'46K7897'
#1e [MN] len=4: b'1037'
#25 [FC] len=4: b'5769'
#2c [SN] len=12: b'YL102035603V'
#3b [NA] len=12: b'00145E992ED1'
007a Small item 1 bytes; name 0xf End Tag
0c00 Large item 16 bytes; name 0x2 Identifier String
b'S310E-SR-X '
0c13 Large item 234 bytes; name 0x10
#00 [PN] len=16: b'TBD '
#13 [EC] len=16: b'110107730D2 '
#26 [SN] len=16: b'97YL102035603V '
#39 [NA] len=12: b'00145E992ED1'
#48 [V0] len=6: b'175000'
#51 [V1] len=6: b'266666'
#5a [V2] len=6: b'266666'
#63 [V3] len=6: b'2000 '
#6c [V4] len=2: b'1 '
#71 [V5] len=6: b'c2 '
#7a [V6] len=6: b'0 '
#83 [V7] len=2: b'1 '
#88 [V8] len=2: b'0 '
#8d [V9] len=2: b'0 '
#92 [VA] len=2: b'0 '
#97 [RV] len=80: b's\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'...
0d00 Large item 252 bytes; name 0x11
#00 [VC] len=16: b'122310_1222 dp '
#13 [VD] len=16: b'610-0001-00 H1\x00\x00'
#26 [VE] len=16: b'122310_1353 fp '
#39 [VF] len=16: b'610-0001-00 H1\x00\x00'
#4c [RW] len=173: b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'...
0dff Small item 0 bytes; name 0xf End Tag
10f3 Large item 13315 bytes; name 0x62
!!! unknown item name 98: b'\xd0\x03\x00@`\x0c\x08\x00\x00\x00\x00\x00\x00\x00\x00\x00'
===
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
It's not very enlightening to see
pci 0000:07:00.0: [Firmware Bug]: VPD access disabled
in the dmesg log because there's no clue about what the firmware bug is.
Expand the message to explain why we're disabling VPD.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Remove the "PCI Express Hot Plug Controller Driver" version message. I
don't think it contains any useful information. Remove unused #defines
and move the author information to a comment.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Remove the "PCI Hot Plug PCI Core" version message. I don't think it
contains any useful information. Remove unused #defines and move the
author information to a comment.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Remove the "service driver %s loaded" and unloaded messages. All service
drivers already log something in their probe functions, where they can log
more useful details.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
All other AER-related log messages use the PCI device, e.g.,
"pci 0000:00:1c.0", not the PCIe service device, e.g.,
"aer 0000:00:1c.0:pcie02".
Change the probe error messages to match the rest and include a little
context.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Remove the unused DRIVER_VERSION, DRIVER_AUTHOR, and DRIVER_DESC macros.
The author information is already included in a comment above.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
We already log a "Signaling PME" whenever the PME service driver claims a
Root Port. In fact, we also log the same message for every device in the
hierarchy below the Root Port.
Log the "Signaling PME" once (only for the Root Port, since we can
trivially find out which devices are below the Root Port), and include the
IRQ number in the message to help connect the dots with /proc/interrupts.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since we register pcie_pme_driver only for PCI_EXP_TYPE_ROOT_PORT, the PME
driver never claims Root Complex Event Collectors.
Remove unused code related to Root Complex Event Collectors.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Move PCI configuration space size macros (PCI_CFG_SPACE_SIZE and
PCI_CFG_SPACE_EXP_SIZE) from drivers/pci/pci.h to
include/uapi/linux/pci_regs.h so they can be used by more drivers and
eliminate duplicate definitions.
[bhelgaas: Expand comment to include PCI-X details]
Signed-off-by: Wang Sheng-Hui <shhuiw@foxmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This struct never needs to be modified. The size of pci-mid.o ELF
sections changes thusly:
-.data 56
+.data 0
-.rodata 32
+.rodata 88
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Some (defective) PCIe devices are not able to reliably do link retraining.
Check to see if ASPM is possible between link partners before configuring
common clocking, and doing the resulting link retraining. If ASPM is not
possible, there is no reason to risk losing access to a device due to an
unnecessary link retraining.
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
PAXC and PAXCv2 buses do not support legacy IRQs so there is no reason to
even try and map them. Without a change like this, one cannot create VFs
on Nitro ports since legacy interrupts are checked as part of the PCI
device creation process. Testing on PAXC hardware showed that VFs are
properly created with only the change to not set pcie->map_irq, but just to
be safe the change in iproc_pcie_setup() will ensure that pdev_fixup_irq()
will not panic.
Signed-off-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Ray Jui <ray.jui@broadcom.com>
If an error occurs when enabling a slot, pciehp_power_thread() turns off
the power indicator. But if the only error is that the slot was already
enabled, we should leave the power indicator on.
Return success if called to enable an already-enabled slot.
This is in the same spirit of the special handling for EEXISTS when
pciehp_configure_device() determines the slot devices already exist.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
If Slot Status indicates changes in both Data Link Layer Status and
Presence Detect, prioritize the Link status change.
When both events are observed, pciehp currently relies on the Slot Status
Presence Detect State (PDS) to agree with the Link Status Data Link Layer
Active status. The Presence Detect State, however, may be set to 1 through
out-of-band presence detect even if the link is down, which creates
conflicting events.
Since the Link Status accurately reflects the reachability of the
downstream bus, the Link Status event should take precedence over a
Presence Detect event. Skip checking the PDC status if we handled a link
event in the same handler.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Add Makefile comments to explain the Kconfig and build strategy for ARM64
drivers that work around not-quite-ECAM issues. No functional change
intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
PCIe controllers in X-Gene SoCs are not ECAM compliant: software needs to
configure additional controller's register to address device at
bus:dev:function.
Add a quirk to discover controller MMIO register space and configure
controller registers to select and address the target secondary device.
The quirk will only be applied for X-Gene PCIe MCFG table with
OEM revison 1, 2, 3 or 4 (PCIe controller v1 and v2 on X-Gene SoCs).
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Duc Dang <dhdang@apm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
ThunderX pass1.x requires to emulate the EA headers for on-chip devices
hence it has to use custom pci_thunder_ecam_ops for accessing PCI config
space (pci-thunder-ecam.c). Add new entries to MCFG quirk array where it
can be applied while probing ACPI based PCI host controller.
ThunderX pass1.x is using the same way for accessing off-chip devices
(so-called PEM) as silicon pass-2.x so we need to add PEM quirk entries
too.
Quirk is considered for ThunderX silicon pass1.x only which is identified
via MCFG revision 2.
ThunderX pass 1.x requires the following accessors:
NUMA node 0 PCI segments 0- 3: pci_thunder_ecam_ops (MCFG quirk)
NUMA node 0 PCI segments 4- 9: thunder_pem_ecam_ops (MCFG quirk)
NUMA node 1 PCI segments 10-13: pci_thunder_ecam_ops (MCFG quirk)
NUMA node 1 PCI segments 14-19: thunder_pem_ecam_ops (MCFG quirk)
[bhelgaas: change Makefile/ifdefs so quirk doesn't depend on
CONFIG_PCI_HOST_THUNDER_ECAM]
Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
ThunderX PCIe controller to off-chip devices (so-called PEM) is not fully
compliant with ECAM standard. It uses non-standard configuration space
accessors (see thunder_pem_ecam_ops) and custom configuration space
granulation (see bus_shift = 24). In order to access configuration space
and probe PEM as ACPI-based PCI host controller we need to add MCFG quirk
infrastructure. This involves:
1. A new thunder_pem_acpi_init() init function to locate PEM-specific
register ranges using ACPI.
2. Export PEM thunder_pem_ecam_ops structure so it is visible to MCFG quirk
code.
3. New quirk entries for each PEM segment. Each contains platform IDs,
mentioned thunder_pem_ecam_ops and CFG resources.
Quirk is considered for ThunderX silicon pass2.x only which is identified
via MCFG revision 1.
ThunderX pass 2.x requires the following accessors:
NUMA Node 0 PCI segments 0- 3: pci_generic_ecam_ops (ECAM-compliant)
NUMA Node 0 PCI segments 4- 9: thunder_pem_ecam_ops (MCFG quirk)
NUMA Node 1 PCI segments 10-13: pci_generic_ecam_ops (ECAM-compliant)
NUMA Node 1 PCI segments 14-19: thunder_pem_ecam_ops (MCFG quirk)
[bhelgaas: adapt to use acpi_get_rc_resources(), update Makefile/ifdefs so
quirk doesn't depend on CONFIG_PCI_HOST_THUNDER_PEM]
Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Pull the register resource lookup out of thunder_pem_init() so we can
easily add a corresponding lookup using ACPI. No functional change
intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The PCIe controller in Hip05/Hip06/Hip07 SoCs is not completely
ECAM-compliant. It is non-ECAM only for the RC bus config space; for any
other bus underneath the root bus it does support ECAM access.
Add specific quirks for PCI config space accessors. This involves:
1. New initialization call hisi_pcie_init() to obtain RC base
addresses from PNP0C02 at the root of the ACPI namespace (under \_SB).
2. New entry in common quirk array.
[bhelgaas: move to pcie-hisi.c and change Makefile/ifdefs so quirk doesn't
depend on CONFIG_PCI_HISI]
Signed-off-by: Dongdong Liu <liudongdong3@huawei.com>
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The Qualcomm Technologies QDF2432 SoC does not support accesses smaller
than 32 bits to the PCI configuration space. Register the appropriate
quirk.
[bhelgaas: add QCOM_ECAM32 macro, ifdef for ACPI and PCI_QUIRKS]
Signed-off-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The acpi_get_rc_resources() is used to get the RC register address that can
not be described in MCFG. It takes the _HID & segment to look for and
outputs the RC address resource. Use PNP0C02 devices to describe such RC
address resource. Use _UID to match segment to tell which root bus the
PNP0C02 resource belongs to.
[bhelgaas: add dev argument, wrap in #ifdef CONFIG_PCI_QUIRKS]
Signed-off-by: Dongdong Liu <liudongdong3@huawei.com>
Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The PCIe spec (r3.0, sec 7.2.2) specifies an "Enhanced Configuration Access
Mechanism" (ECAM) for memory-mapped access to configuration space. ECAM is
required for PCIe systems unless there's a standard firmware interface for
config access.
In the absence of a firmware interface, we use pci_generic_ecam_ops, and on
ACPI systems, we discover the ECAM space via the MCFG table and/or the _CBA
method.
Unfortunately some systems provide MCFG but don't implement ECAM according
to spec, so we need a mechanism for quirks to make those systems work.
Add an MCFG quirk mechanism to override the config accessor functions
and/or the memory-mapped address space.
A quirk is selected if it matches all of the following:
- OEM ID
- OEM Table ID
- OEM Revision
- PCI segment (from _SEG)
- PCI bus number range (from _CRS, wildcard allowed)
If the quirk specifies config accessor functions or a memory-mapped address
range, these override the defaults.
[bhelgaas: changelog, reorder quirk matching, fix oem_revision typo per
Duc, add under #ifdef CONFIG_PCI_QUIRKS]
Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Signed-off-by: Dongdong Liu <liudongdong3@huawei.com>
Signed-off-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
pci_mcfg_lookup() is the external interface to the generic MCFG code.
Previously it merely looked up the ECAM base address for a given domain and
bus range. We want a way to add MCFG quirks, some of which may require
special config accessors and adjustments to the ECAM address range.
Extend pci_mcfg_lookup() so it can return a pointer to a pci_ecam_ops
structure and a struct resource for the ECAM address space. For now, it
always returns &pci_generic_ecam_ops (the standard accessor) and the
resource described by the MCFG.
No functional changes intended.
[bhelgaas: changelog]
Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
On x86 and ia64, we have treated all ACPI _CRS resources of PNP0A03 host
bridge devices as "producers", i.e., as host bridge windows. That's partly
because some x86 BIOSes improperly used "consumer" descriptors to describe
windows and partly because Linux didn't have good support for handling
consumer and producer descriptors differently.
One result is that x86 BIOSes describe host bridge "consumer" resources in
the _CRS of a PNP0C02 device, not the PNP0A03 device itself. On arm64 we
don't have a legacy of firmware that has this consumer/producer confusion,
so we can handle PNP0A03 "consumer" descriptors as host bridge registers
instead of windows.
Exclude non-window ("consumer") resources from the list of host bridge
windows. This allows the use of "consumer" PNP0A03 descriptors for bridge
register space.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Currently we use one shared global acpi_pci_root_ops structure to keep
controller-specific ops. We pass its pointer to acpi_pci_root_create() and
associate it with a host bridge instance for good. Such a design implies
serious drawback. Any potential manipulation on the single system-wide
acpi_pci_root_ops leads to kernel crash. The structure content is not
really changing even across multiple host bridges creation; thus it was not
an issue so far.
In preparation for adding ECAM quirks mechanism (where controller-specific
PCI ops may be different for each host bridge) allocate new
acpi_pci_root_ops and fill in with data for each bridge. Now it is safe to
have different controller-specific info. As a consequence free
acpi_pci_root_ops when host bridge is released.
No functional changes in this patch.
Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
The static MCFG table tells us the base of ECAM space, but it does not
reserve the space -- the reservation should be done via a device in the
ACPI namespace whose _CRS includes the ECAM region.
Use acpi_resource_consumer() to check whether the ECAM space is reserved by
an ACPI namespace device. If it is, emit a message showing which device
reserves it. If not, emit a "[Firmware Bug]" warning.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Use a local "struct device *dev" for brevity. No functional change
intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Add acpi_resource_consumer(). This takes a struct resource and searches
the ACPI namespace for a device whose current resource settings (_CRS)
includes the resource. It returns the device if it exists, or NULL if no
device uses the resource.
If more than one device uses the resource (this may happen in the case of
bridges), acpi_resource_consumer() returns the first one found by
acpi_get_devices() in its modified depth-first walk of the namespace.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
pci_update_resource() updates a hardware BAR so its address matches the
kernel's struct resource UNLESS it's a disabled ROM BAR. We only update
those when we enable the ROM.
It's not obvious from the code why ROM BARs should be handled specially.
Apparently there are Matrox devices with defective ROM BARs that read as
zero when disabled. That means that if pci_enable_rom() reads the disabled
BAR, sets PCI_ROM_ADDRESS_ENABLE (without re-inserting the address), and
writes it back, it would enable the ROM at address zero.
Add comments and references to explain why we can't make the code look more
rational.
The code changes are from 755528c860 ("Ignore disabled ROM resources at
setup") and 8085ce084c ("[PATCH] Fix PCI ROM mapping").
Link: https://lkml.org/lkml/2005/8/30/138
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Remove the assumption that IORESOURCE_ROM_ENABLE == PCI_ROM_ADDRESS_ENABLE.
PCI_ROM_ADDRESS_ENABLE is the ROM enable bit defined by the PCI spec, so if
we're reading or writing a BAR register value, that's what we should use.
IORESOURCE_ROM_ENABLE is a corresponding bit in struct resource flags.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
pci_std_update_resource() only deals with standard BARs, so we don't have
to worry about the complications of VF BARs in an SR-IOV capability.
Compute the BAR address inline and remove pci_resource_bar(). That makes
pci_iov_resource_bar() unused, so remove that as well.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
If we update a VF BAR while it's enabled, there are two potential problems:
1) Any driver that's using the VF has a cached BAR value that is stale
after the update, and
2) We can't update 64-bit BARs atomically, so the intermediate state
(new lower dword with old upper dword) may conflict with another
device, and an access by a driver unrelated to the VF may cause a bus
error.
Warn about attempts to update VF BARs while they are enabled. This is a
programming error, so use dev_WARN() to get a backtrace.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Previously pci_update_resource() used the same code path for updating
standard BARs and VF BARs in SR-IOV capabilities.
Split the VF BAR update into a new pci_iov_update_resource() internal
interface, which makes it simpler to compute the BAR address (we can get
rid of pci_resource_bar() and pci_iov_resource_bar()).
This patch:
- Renames pci_update_resource() to pci_std_update_resource(),
- Adds pci_iov_update_resource(),
- Makes pci_update_resource() a wrapper that calls the appropriate one,
No functional change intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>