o FLR from Hypervisor - When hypervisor issues a VF FLR request,
  adapter notifies the parent PF driver of the FLR request for PF
  driver to perform any cleanup on behalf of that VF.
o FLR from VF Driver - VF driver may initiate a VF FLR request,
  if VF state needs to be cleaned up before a re-initialization.
  VF re-initialization during kdump is an example.
o PF driver cleans up all resources allocated on behalf of a  VF,
  on VF FLR notifications from the adapter or from the VF driver.
Signed-off-by: Manish Chopra <manish.chopra@qlogic.com>
Signed-off-by: Sucheta Chakraborty <sucheta.chakraborty@qlogic.com>
Signed-off-by: Rajesh Borundia <rajesh.borundia@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

o 82xx adapter requires VLAN id in little endian format.
  Instead of passing vlan id parameter as __le16, pass the
  parameter as u16 and  use cpu_to_le16 at appropriate places.
Signed-off-by: Rajesh Borundia <rajesh.borundia@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Patrick McHardy says:

====================
The following patches contain an implementation of memory mapped I/O for
netlink. The implementation is modelled after AF_PACKET memory mapped I/O
with a few differences:

- In order to perform memory mapped I/O to userspace, the kernel allocates
  skbs with the data area pointing to the data area of the mapped frames.
  All netlink subsystems assume a linear data area, so for the sake of
  simplicity, the mapped data area is not attached to the paged area but
  to skb->data. This requires introduction of a special skb alloction
  function that just allocates an skb head without the data area. Since this
  is a quite rare use case, I introduced a new function based on __alloc_skb
  instead of splitting it up into head and data alloction. The alternative
  would be to   introduce an __alloc_skb_head and __alloc_skb_data function,
  which would actually be useful for a specific error case in memory mapped
  netlink, but would require a couple of extra instructions for the common
  skb allocation case, so it doesn't really seem worth it.

  In order to get the destination memory area for skb->data before message
  construction, memory mapped netlink I/O needs to look up the destination
  socket during allocation instead of during transmission because the
  ring is owned by the receiveing socket/process. A special skb allocation
  function (netlink_alloc_skb) taking the destination pid as an argument is
  used for this, all subsystems that want to support memory mapped I/O need
  to use this function, automatic fallback to the receive queue happens
  for unconverted subsystems. Dumps automatically use memory mapped I/O if
  the receiving socket has enabled it.

  The visible effect of looking up the destination socket during allocation
  instead of transmission is that message ordering in userspace might
  change in case allocation and transmission aren't performed atomically.
  This usually doesn't matter since most subsystems have a BKL-like lock
  like the rtnl mutex, to my knowledge the currently only existing case
  where it might matter is nfnetlink_queue combined with the recently
  introduced batched verdicts, but a) that subsystem already includes
  sequence numbers which allow userspace to reorder messages in case it
  cares to, also the reodering window is quite small and b) with memory
  mapped transmission batching can be performed in a subsystem indepandant
  manner.

- AF_NETLINK contains flow control for database dumps, with regular I/O
  dump continuation are triggered based on the sockets receive queue space
  and by recvmsg() calls. Since with memory mapped I/O there are no
  recvmsg() calls under normal operation, this is done in netlink_poll(),
  under the assumption that userspace has processed all pending frames
  before invoking poll(), thus the ring is expected to have room for new
  messages. Dumps currently don't benefit as much as they could from
  memory mapped I/O because each single continuation requires a poll()
  call. A more agressive approach seems like a good idea to me, especially
  in case the socket is not subscribed to any multicast groups (IOW only
  receiving explicitly requested data).

Besides that, the memory mapped netlink implementation extends the states
defined by AF_PACKET between userspace and the kernel by a SKIP status, this
is intended for the case that userspace wants to queue frames (specifically
when using nfnetlink_queue, an IDS and stream reassembly, requested by
Eric Leblond) for a longer period of time. The kernel skips over all frames
marked with SKIP when looking or unused frames and only fails when not finding
a free frame or when having skipped the entire ring.

Also noteworthy is memory mapped sendmsg: the kernel performs validation
of messages before accepting and processing them, in order to prevent
userspace from changing the messages contents after validation, the
kernel checks that the ring is only mapped once and the file descriptor
is not shared (in order to avoid having userspace set up another mapping
after the first mentioned check). If either of both is not true, the
message copied to an allocated skb and processed as with regular I/O.
I'd especially appreciate review of this part since I'm not really versed
in memory, file and process management,

The remaining interesting details are included in the changelogs of the
individual patches and the documentation, so I won't repeat them here.

As an example, nfnetlink_queue is convererted to support memory mapped
I/O. Other subsystems that would probably benefit are nfnetlink_log,
audit and maybe ISCSI, not sure.

Following are some numbers collected by Florian Westphal based on a
slightly older version, which included an experimental patch for the
nfnetlink_queue ordering issue.

===

Test hardware is a 12-core machine
Intel(R) Xeon(R) CPU E5-2620 0 @ 2.00GHz
ixgbe interfaces are used (i.e., multiqueue nics).
irqs are distributed across the cpus.

I've made several tests.

The simple one consists of 3GBit UDP traffic, packets are 1500 bytes
in size (i.e., no fragmentation), with a single nfqueue
and the test client programs in libmnl examples directory.
Packets are sent from one /24 net to another /24 net, i.e.
there are a few hundred flows active at any given time.

I've also tested with snort, but I disabled all rules.
6Gbit UDP traffic is generated in the snort case, and
6 nfqueues are used (i.e., 6 snorts run in parallel).

I've tested with 3 different kernels, all based on 3.7.1.
- 3.7.1, without the mmap patches
- 3.7.1, with Patricks mmap patches
- 3.7.1, with mmap patches and extended spinlock to ensure packet ids are
  monotonically increasing and cannot be re-ordered.  This is what we
  currently ship in our product.

  [ the spinlock that is extended is the per nfqueue spinlock, it will
    be held from the time the netlink skb is allocated until the netlink
    skb is sent to userspace:

    http://1984.lsi.us.es/git/nf-next/commit/?h=mmap-netlink3&id=b8eb19c46650fef4e9e4fe53f367f99bbf72afc9
  ]

snort is normally used in "batch mode", i.e., after processing 25 packets
a single "batch verdict" is sent to accept the packets seen so far.
"mmap snort" means RX_RING + sendmsg(), i.e. TX_RING is not used at this
time (except where noted below).

One reason is that snort has a reload thread, so kernel needs to copy;
also in the snort case no payload rewrite takes place, so compared
to the rx path the tx path is cheap.

Results:

3.7.1, without mmap patches, i.e. recv()+sendmsg() for everyone
nfq-queue:           1.7 gbit out
snort-recv-batch-25  5.1 gbit out
snort-recv-no-batch  3.1 gbit out

3.7.1 + mmap + without extended spinlocked section
nfq-queue:           1.7 gbit out (recv/sendmsg)
nfq-queue-mmap:      2.4 gbit out
snort-mmap-batch-25	 5.6 gbit out  (warning: since ids can be
                                        re-ordered, this version is "broken").
snort-recv-batch-25	 5.1 gbit out
snort-mmap-no-batch	 4.6 gbit out (i.e., one verdict per packet)

Kernel 3.7.1 + mmap + extended spinlock section:
nfq-queue:	1.4 gbit out
nfq-queue-mmap: 2.3 gbit out
snort:          5.6 gbit out

Conclusions:
- The "extended spinlocked section" hurts performance in the
  single queue case; with 6 snorts there is no measureable slowdown.
- I tried to re-write the mmap-snort to work without batch verdicts, but
  results were not very encouraging:

kernel 3.7.1 + mmap (without extended spinlocked section):

snort-mmap-batch-25      5.6 gbit out (what we currenlty ship)
snort-recv-batch-25      5.1 gbit out (without using mmap)
snort-mmap-batch-1       4.6 gbit out (with mmap but without batch verdicts)
snort-mmap-txring-25     5.2 gbit out (with mmap but without batch verdicts)
snort-mmap-txring-1      4.6 gbit out (with mmap but without batch verdicts)

The difference between the last two is that in the txring-25 case, we
put a verdict into the tx ring after every packet, but will only
invoke sendmsg(, NULL, 0) after processing 25 packets.  So the only
difference is the number of sendmsg calls/context switches.

So, i.o.w, kernel 3.7.1 + mmap + the extra locking crap is faster
than 3.7.1 + mmap-without-extra-locking and single-verdict-per packet.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Get rid of the confusing mix of pid and portid and use portid consistently
for all netlink related socket identities.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Based on AF_PACKET.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add flow control for memory mapped RX. Since user-space usually doesn't
invoke recvmsg() when using memory mapped I/O, flow control is performed
in netlink_poll(). Dumps are allowed to continue if at least half of the
ring frames are unused.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for mmap'ed recvmsg(). To allow the kernel to construct messages
into the mapped area, a dataless skb is allocated and the data pointer is
set to point into the ring frame. This means frames will be delivered to
userspace in order of allocation instead of order of transmission. This
usually doesn't matter since the order is either not determinable by
userspace or message creation/transmission is serialized. The only case
where this can have a visible difference is nfnetlink_queue. Userspace
can't assume mmap'ed messages have ordered IDs anymore and needs to check
this if using batched verdicts.

For non-mapped sockets, nothing changes.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for mmap'ed sendmsg() to netlink. Since the kernel validates
received messages before processing them, the code makes sure userspace
can't modify the message contents after invoking sendmsg(). To do that
only a single mapping of the TX ring is allowed to exist and the socket
must not be shared. If either of these two conditions does not hold, it
falls back to copying.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add helper functions for looking up mmap'ed frame headers, reading and
writing their status, allocating skbs with mmap'ed data areas and a poll
function.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for mmap'ed RX and TX ring setup and teardown based on the
af_packet.c code. The following patches will use this to add the real
mmap'ed receive and transmit functionality.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

For mmap'ed I/O a netlink specific skb destructor needs to be invoked
after the final kfree_skb() to clean up state. This doesn't work currently
since the skb's ownership is transfered to the receiving socket using
skb_set_owner_r(), which orphans the skb, thereby invoking the destructor
prematurely.

Since netlink doesn't account skbs to the originating socket, there's no
need to orphan the skb. Add a netlink specific skb_set_owner_r() variant
that does not orphan the skb and use a netlink specific destructor to
call sock_rfree().
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Netlink doesn't account skbs to the sending socket, so the there's no
need to orphan the skb before trimming it.

Removing the skb_orphan() call is required for mmap'ed netlink, which uses
a netlink specific skb destructor that must not be invoked before the
final freeing of the skb.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a function to allocate a sk_buff head without any data. This will
be used by memory mapped netlink to attach data from the mmaped area
to the skb.

Additionally change skb_release_all() to check whether the skb has a
data area to allow the skb destructor to clear the data pointer in case
only a head has been allocated.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Memory mapped netlink needs to store the receiving userspace socket
when sending from the kernel to userspace. Rename 'ssk' to 'sk' to
avoid confusion.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Patrick McHardy says:

====================
The following patches add support for 802.1ad (provider tagging) to the
VLAN driver. The patchset consists of the following parts:

- renaming of the NET_F_HW_VLAN feature flags to indicate that they only
  operate on CTAGs

- preparation for 802.1ad VLAN filtering offload by adding a proto argument
  to the rx_{add,kill}_vid net_device_ops callbacks

- preparation of the VLAN code to support multiple protocols by making the
  protocol used for tagging a property of the VLAN device and converting
  the device lookup functions accordingly

- second step of preparation of the VLAN code by making the packet tagging
  functions take a protocol argument

- introducation of 802.1ad support in the VLAN code, consisting mainly of
  checking for ETH_P_8021AD in a couple of places and testing the netdevice
  offload feature checks to take the protocol into account

- announcement of STAG offloading capabilities in a couple of drivers for
  virtual network devices

The patchset is based on net-next.git and has been tested with single and
double tagging with and without HW acceleration (for CTAGs).
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

- macvlan: propagate STAG filtering capabilities from underlying device
- ifb: announce STAG tagging support in addition to CTAG tagging support
- veth: announce STAG tagging/stripping support in addition to CTAG support
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for 802.1ad VLAN devices. This mainly consists of checking for
ETH_P_8021AD in addition to ETH_P_8021Q in a couple of places and check
offloading capabilities based on the used protocol.

Configuration is done using "ip link":

# ip link add link eth0 eth0.1000 \
	type vlan proto 802.1ad id 1000
# ip link add link eth0.1000 eth0.1000.1000 \
	type vlan proto 802.1q id 1000

52:54:00:12:34:56 > 92:b1:54:28:e4:8c, ethertype 802.1Q (0x8100), length 106: vlan 1000, p 0, ethertype 802.1Q, vlan 1000, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
    20.1.0.2 > 20.1.0.1: ICMP echo request, id 3003, seq 8, length 64
92:b1:54:28:e4:8c > 52:54:00:12:34:56, ethertype 802.1Q-QinQ (0x88a8), length 106: vlan 1000, p 0, ethertype 802.1Q, vlan 1000, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 47944, offset 0, flags [none], proto ICMP (1), length 84)
    20.1.0.1 > 20.1.0.2: ICMP echo reply, id 3003, seq 8, length 64
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a protocol argument to the VLAN packet tagging functions. In case of HW
tagging, we need that protocol available in the ndo_start_xmit functions,
so it is stored in a new field in the skb. The new field fits into a hole
(on 64 bit) and doesn't increase the sks's size.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Make the encapsulation protocol value a property of VLAN devices and change
the device lookup functions to take the protocol value into account.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Change the rx_{add,kill}_vid callbacks to take a protocol argument in
preparation of 802.1ad support. The protocol argument used so far is
always htons(ETH_P_8021Q).
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Rename the hardware VLAN acceleration features to include "CTAG" to indicate
that they only support CTAGs. Follow up patches will introduce 802.1ad
server provider tagging (STAGs) and require the distinction for hardware not
supporting acclerating both.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
This series contains updates to ixgbe and igb.

The ixgbe changes contains 2 patches from the community, one which is a
fix from akepner to fix a issue where netif_running() in shutdown was
not done under rtnl_lock.  The other community fix from Joe Perches
cleans up #ifdef CONFIG_DEBUG_FS which is no longer necessary.  The
last ixgbe patch, from Jacob Keller, adds support for WoL on 82559
SFP+ LOM.

The remaining patches are against igb, 10 of which were previously
submitted in a pull request where changes were requested.

The following igb patches:
 igb: Support for 100base-fx SFP
 igb: Support to read and export SFF-8472/8079 data
are v2 based on feedback from Dan Carpenter and Ben Hutchings in
the previous pull request.

The largest set of changes are in my patch to cleanup code comments
and whitespace to align the igb driver with the networking style of
code comments.  While cleaning up the code comments, fixed several
other whitespace/checkpatch.pl code formatting issues.

Other notable igb patches are EEE capable devices query the PHY to
determine what the link partner is advertising, added support for
i354 devices and added support for spoofchk config.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds base support for new i354 devices.  Loopback test is
unsupported for this release.
Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Add support for spoofchk configuration per VF via iproute2 tool.
Signed-off-by: Lior Levy <lior.levy@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

On EEE-capable devices, query the PHY to determine what the link partner is
advertising.
Signed-off-by: Matthew Vick <matthew.vick@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Aligns the multi-line code comments with the desired style for the
networking tree.  Also cleaned up whitespace issues found during the
cleanup of code comments (i.e. remove unnecessary blank lines,
use tabs where possible, properly wrap lines and keep strings on a
single line)
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>

This patch fixes sparse warnings on function pointers that are not
defined as static.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

It turns out that the InterruptThrottleRate module parameter was only
having the effect of locking the ITR at the starting ITR value. This was
because the values stored in rx_itr_setting and tx_itr_setting were being
ignored when configuring the initial itr_val of the q_vector.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

We only need the adapter pointer in the case of ptp.  As such we can pull the
adapter out of the main path and place it inside the if statement to avoid
the temptation of accessing the adapter pointer in the fast path.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

We were incorrectly checking the entire frag_off field when we only wanted the
fragment offset.  As a result we were not pulling in TCP headers when the DNF
flag was set.

To correct that we will now check for frag off using the IP_OFFSET mask.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch fixes code and comments as identified in the driver.
Signed-off-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Based on original patch from Aurélien Guillaume <footplus@gmail.com>
This patch adds support to turn on I2C, with sfp cage powered.

CC: Aurélien Guillaume <footplus@gmail.com>
Signed-off-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch adds support to read and export SFF-8472/8079 (SFP data)
over i2c, through Ethtool.

v2: Changed implementation to accommodate any offset within SFF module
    length boundary.
Reported-by: Aurélien Guillaume <footplus@gmail.com>
CC: Aurélien Guillaume <footplus@gmail.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch adds support for 100base-fx SFP and report proper link speed/duplex
via Ethtool.

v2: fix smatch warnings

CC: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Add some empty static inlines instead to make
the code more readable.
Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch adds software support for WoL for the 82599 SFP+ LOM device,
(ID 0x8976)
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

During shutdown it's possible for __dev_close() (which holds
rtnl_lock) to clear the __LINK_STATE_START bit, and for ixgbe
to then read that bit (without holding rtnl_lock), and then
not fail to free irqs, etc. The result is a crash like this:

------------[ cut here ]------------
kernel BUG at drivers/pci/msi.c:313!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map
CPU 1
Pid: 5910, comm: reboot Tainted: P           ----------------   2.6.32 #1 empty
RIP: 0010:[<ffffffff81305c2b>]  [<ffffffff81305c2b>] free_msi_irqs+0x11b/0x130
RSP: 0018:ffff880185c9bc88  EFLAGS: 00010282
RAX: ffff880219f58bc0 RBX: ffff88021ac53b00 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000246 RDI: 000000000000004a
RBP: ffff880185c9bcc8 R08: 0000000000000002 R09: 0000000000000106
R10: 0000000000000000 R11: 0000000000000006 R12: ffff88021e524778
R13: 0000000000000001 R14: ffff88021e524000 R15: 0000000000000000
FS:  00007f90821b7700(0000) GS:ffff880028220000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007f90818bd010 CR3: 0000000132c64000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process reboot (pid: 5910, threadinfo ffff880185c9a000, task ffff88021bf04a80)
Stack:
 ffff880185c9bc98 000000018130529d ffff880185c9bcc8 ffff88021e524000
<0> 0000000000000004 ffff88021948c700 0000000000000000 ffff880185c9bda7
<0> ffff880185c9bce8 ffffffff81305cbd ffff880185c9bce8 ffff88021948c700
Call Trace:
 [<ffffffff81305cbd>] pci_disable_msix+0x3d/0x50
 [<ffffffffa00501d5>] ixgbe_reset_interrupt_capability+0x65/0x90 [ixgbe]
 [<ffffffffa00512f6>] ixgbe_clear_interrupt_scheme+0xb6/0xd0 [ixgbe]
 [<ffffffffa005330b>] __ixgbe_shutdown+0x5b/0x200 [ixgbe]
 [<ffffffffa00534ca>] ixgbe_shutdown+0x1a/0x60 [ixgbe]
 [<ffffffff812f6c7c>] pci_device_shutdown+0x2c/0x50
 [<ffffffff813727fb>] device_shutdown+0x4b/0x160
 [<ffffffff8107d98c>] kernel_restart_prepare+0x2c/0x40
 ehci timer_action, mod_timer io_watchdog
 [<ffffffff8107d9e6>] kernel_restart+0x16/0x60
 [<ffffffff8107dbfd>] sys_reboot+0x1ad/0x200
 [<ffffffff811676cf>] ? __d_free+0x3f/0x60
 [<ffffffff81167748>] ? d_free+0x58/0x60
 [<ffffffff8116f7c0>] ? mntput_no_expire+0x30/0x100
 [<ffffffff81152b11>] ? __fput+0x191/0x200
 [<ffffffff816565fe>] ? do_page_fault+0x3e/0xa0
 [<ffffffff8100b132>] system_call_fastpath+0x16/0x1b
Code: 4c 89 ef e8 98 8c e3 ff 4d 39 f4 48 8b 43 10 75 cf 48 83 c4 18 5b 41 5c
41 5d 41 5e 41 5f c9 c3 49 8b 7d 20 e8 07 5a d3 ff eb c9 <0f> 0b 0f 1f 00 eb fb
66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00
 ehci timer_action, mod_timer io_watchdog
RIP  [<ffffffff81305c2b>] free_msi_irqs+0x11b/0x130
 RSP <ffff880185c9bc88>
---[ end trace 27de882a0fe75593 ]---

(This was seen on a pretty old kernel/driver, but looks like
the same bug is still possible.)

Signed-off-by: <akepner@riverbed.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>