There is inline function to test if carrier present,
so it makes open-coded solution redundant.
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Acked-by: NYuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

BBR congestion control depends on pacing, and pacing is
currently handled by sch_fq packet scheduler for performance reasons,
and also because implemening pacing with FQ was convenient to truly
avoid bursts.

However there are many cases where this packet scheduler constraint
is not practical.
- Many linux hosts are not focusing on handling thousands of TCP
  flows in the most efficient way.
- Some routers use fq_codel or other AQM, but still would like
  to use BBR for the few TCP flows they initiate/terminate.

This patch implements an automatic fallback to internal pacing.

Pacing is requested either by BBR or use of SO_MAX_PACING_RATE option.

If sch_fq happens to be in the egress path, pacing is delegated to
the qdisc, otherwise pacing is done by TCP itself.

One advantage of pacing from TCP stack is to get more precise rtt
estimations, and less work done from TX completion, since TCP Small
queue limits are not generally hit. Setups with single TX queue but
many cpus might even benefit from this.

Note that unlike sch_fq, we do not take into account header sizes.
Taking care of these headers would add additional complexity for
no practical differences in behavior.

Some performance numbers using 800 TCP_STREAM flows rate limited to
~48 Mbit per second on 40Gbit NIC.

If MQ+pfifo_fast is used on the NIC :

$ sar -n DEV 1 5 | grep eth
14:48:44         eth0 725743.00 2932134.00  46776.76 4335184.68      0.00      0.00      1.00
14:48:45         eth0 725349.00 2932112.00  46751.86 4335158.90      0.00      0.00      0.00
14:48:46         eth0 725101.00 2931153.00  46735.07 4333748.63      0.00      0.00      0.00
14:48:47         eth0 725099.00 2931161.00  46735.11 4333760.44      0.00      0.00      1.00
14:48:48         eth0 725160.00 2931731.00  46738.88 4334606.07      0.00      0.00      0.00
Average:         eth0 725290.40 2931658.20  46747.54 4334491.74      0.00      0.00      0.40
$ vmstat 1 5
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 4  0      0 259825920  45644 2708324    0    0    21     2  247   98  0  0 100  0  0
 4  0      0 259823744  45644 2708356    0    0     0     0 2400825 159843  0 19 81  0  0
 0  0      0 259824208  45644 2708072    0    0     0     0 2407351 159929  0 19 81  0  0
 1  0      0 259824592  45644 2708128    0    0     0     0 2405183 160386  0 19 80  0  0
 1  0      0 259824272  45644 2707868    0    0     0    32 2396361 158037  0 19 81  0  0

Now use MQ+FQ :

lpaa23:~# echo fq >/proc/sys/net/core/default_qdisc
lpaa23:~# tc qdisc replace dev eth0 root mq

$ sar -n DEV 1 5 | grep eth
14:49:57         eth0 678614.00 2727930.00  43739.13 4033279.14      0.00      0.00      0.00
14:49:58         eth0 677620.00 2723971.00  43674.69 4027429.62      0.00      0.00      1.00
14:49:59         eth0 676396.00 2719050.00  43596.83 4020125.02      0.00      0.00      0.00
14:50:00         eth0 675197.00 2714173.00  43518.62 4012938.90      0.00      0.00      1.00
14:50:01         eth0 676388.00 2719063.00  43595.47 4020171.64      0.00      0.00      0.00
Average:         eth0 676843.00 2720837.40  43624.95 4022788.86      0.00      0.00      0.40
$ vmstat 1 5
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 2  0      0 259832240  46008 2710912    0    0    21     2  223  192  0  1 99  0  0
 1  0      0 259832896  46008 2710744    0    0     0     0 1702206 198078  0 17 82  0  0
 0  0      0 259830272  46008 2710596    0    0     0     0 1696340 197756  1 17 83  0  0
 4  0      0 259829168  46024 2710584    0    0    16     0 1688472 197158  1 17 82  0  0
 3  0      0 259830224  46024 2710408    0    0     0     0 1692450 197212  0 18 82  0  0

As expected, number of interrupts per second is very different.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Van Jacobson <vanj@google.com>
Cc: Jerry Chu <hkchu@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Paolo Abeni says:

====================
udp: scalability improvements

This patch series implement an idea suggested by Eric Dumazet to
reduce the contention of the udp sk_receive_queue lock when the socket is
under flood.

An ancillary queue is added to the udp socket, and the socket always
tries first to read packets from such queue. If it's empty, we splice
the content from sk_receive_queue into the ancillary queue.

The first patch introduces some helpers to keep the udp code small, and the
following two implement the ancillary queue strategy. The code is split
to hopefully help the reviewing process.

The measured overall gain under udp flood is up to the 30% depending on
the numa layout and the number of ingress queue used by the relevant nic.

The performance numbers have been gathered using pktgen as sender, with 64
bytes packets, random src port on a host b2b connected via a 10Gbs link
with the dut.

The receiver used the udp_sink program by Jesper [1] and an h/w l4 rx hash on
the ingress nic, so that the number of ingress nic rx queues hit by the udp
traffic could be controlled via ethtool -L.

The udp_sink program was bound to the first idle cpu, to get more
stable numbers.

On a single numa node receiver:

nic rx queues           vanilla                 patched kernel
1                       1820 kpps               1900 kpps
2                       1950 kpps               2500 kpps
16                      1670 kpps               2120 kpps

When using a single nic rx queue, busy polling was also enabled,
elsewhere, in the above scenario, the bh processing becomes the bottle-neck
and this produces large artifacts in the measured performances (e.g.
improving the udp sink run time, decreases the overall tput, since more
action from the scheduler comes into play).

[1] https://github.com/netoptimizer/network-testing/blob/master/src/udp_sink.c

v1 -> v2:
  Patches 1/3 and 2/3 are unchanged, in patch 3/3 the rx_queue_lock_held param
  of udp_rmem_release() is now a bool.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On packet reception, when we are forced to splice the
sk_receive_queue, we can keep the related lock held, so
that we can avoid re-acquiring it, if fwd memory
scheduling is required.

v1 -> v2:
  the rx_queue_lock_held param in udp_rmem_release() is
  now a bool
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

under udp flood the sk_receive_queue spinlock is heavily contended.
This patch try to reduce the contention on such lock adding a
second receive queue to the udp sockets; recvmsg() looks first
in such queue and, only if empty, tries to fetch the data from
sk_receive_queue. The latter is spliced into the newly added
queue every time the receive path has to acquire the
sk_receive_queue lock.

The accounting of forward allocated memory is still protected with
the sk_receive_queue lock, so udp_rmem_release() needs to acquire
both locks when the forward deficit is flushed.

On specific scenarios we can end up acquiring and releasing the
sk_receive_queue lock multiple times; that will be covered by
the next patch
Suggested-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

And update __sk_queue_drop_skb() to work on the specified queue.
This will help the udp protocol to use an additional private
rx queue in a later patch.
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jakub Kicinski says:

====================
nfp: LSO, checksum and XDP datapath updates

This series introduces a number of refinements to standard features
like LSO and checksum offload.  Three major features are support for
CHECKSUM_COMPLETE, refinement of TSO handling and another small speed
up for XDP TX.  This series also switches from depending on some
app FW<>driver ABI versions to heavier use of capabilities.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Given that our rings are always a power of 2, we can simplify the
calculation of number of completed TX descriptors by using masking
instead of if statement based on whether the index have wrapped
or not.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We have a number of places where we calculate the descriptor
index based on a value which may have overflown.  Create a
macro for masking with the ring size.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since XDP TX ring holds "spare" RX buffers anyway, we don't have to
rush the completion.  We can wait until ring fills up completely
before trying to reclaim buffers.  If RX poll has ended an no
buffer has been queued for XDP TX we have no guarantee we will see
another interrupt, so run the reclaim there as well, to make sure
TX statistics won't become stale.

This should help us reclaim more buffers per single queue controller
register read.

Note that the XDP completion is very trivial, it only adds up
the sizes of transmitted frames for statistics so the latency
spike should be acceptable.  In case user sets the ring sizes
to something crazy, limit the completion to 2k entries.

The check if the ring is empty at the beginning of xdp_complete()
is no longer needed - the callers will perform it.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce NFP_NET_CFG_CTRL_CSUM_COMPLETE capability and implement parsing
of CHECKSUM_COMPLETE metadata.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NEdwin Peer <edwin.peer@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ABI version 4 introduced metadata chaining. Using the ABI version to signal
metadata chaining precludes firmware that advertises new capabilities which
rely on prepended metadata from working on older kernels.

Capability bits are thus better suited to signalling the chained metadata
format. A new version of the RSS capability is introduced to distinguish
between the differing metadata formats for ABI versions other than 4.
Signed-off-by: NEdwin Peer <edwin.peer@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Even if capability for RSS and IRQ moderation are present we may
have not initialized them for control vNIC.  Depend on selected
features mask (ctrl) rather than capabilities (cap) to determine
which features should be enabled.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Firmware advertising the LSO2 capability exploits driver provided L3 and L4
offsets in order to avoid parsing packet headers in the TX path. The vlan
field in struct nfp_net_tx_desc is repurposed, making TXVLAN a mutually
exclusive configuration to LSO2.
Signed-off-by: NEdwin Peer <edwin.peer@netronome.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The l4_offset field referred to by NFD is confusingly named. It is not the
offset of the L4 transport header, but rather the L4 payload.

The LSO2 capability supported by alternative device firmware requires
the actual L4 offset, thus the rename seems prudent.
Signed-off-by: NEdwin Peer <edwin.peer@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We advertise TSO to the stack but leave it disabled by default.
Make sure it's not only disabled in the netdev features but
also on the device itself.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: Nlinzhang <xiaolou4617@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The clean up function is updated to cover duplicate config info in
files included by "source" key word in Ubuntu network config.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On the SPARC platform we need to use the DMA_ATTR_WEAK_ORDERING attribute
in our Rx path dma mapping in order to get the expected performance out
of the receive path.  Adding it to the Tx path has little effect, so
that's not a part of this patch.
Signed-off-by: NShannon Nelson <shannon.nelson@oracle.com>
Reviewed-by: NTushar Dave <tushar.n.dave@oracle.com>
Reviewed-by: NTom Saeger <tom.saeger@oracle.com>
Acked-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Iyappan Subramanian says:

====================
drivers: net: xgene: Add ethtool stats and bug fixes

This patch set,

- adds ethtool extended statistics support
- addresses errata workarounds
- fixes bugs related to statistics

v2: Address review comments from v1
	- Adds lock to protect mdio-xgene indirect MAC access
	- Refactors xgene-enet indirect MAC read/write functions
	- Uses mdio-xgene MAC access routines, if xgene-enet port
	  use the same HW.
v1:
	- Initial version
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NQuan Nguyen <qnguyen@apm.com>
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Prefetch buffer cleanup code was called twice, causing EDAC to
report errors during reboot.

[ 1130.972475] xgene-edac 78800000.edac: IOB bridge agent (BA) transaction
error
[ 1130.979584] xgene-edac 78800000.edac: IOB BA write response error
[ 1130.985648] xgene-edac 78800000.edac: IOB BA write access at 0x00.00000000
()
[ 1130.993612] xgene-edac 78800000.edac: IOB BA requestor ID 0x00002400
[ 1131.000242] xgene-edac 78800000.edac: IOB bridge agent (BA) transaction
error
...

This patch fixes the errors by,

- removing the redundant prefetch buffer cleanup from port_ops->shutdown()
- moving port_ops->shutdown() after delete_rings()
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds workaround for HW errata 10GE_10 and ENET_15:
"HW statistic counters value are duplicated".

- RFCS duplicates RALN counter
- RFLR duplicates RUND counter
- TFCS duplicates TFRG counter
- RALN should be intepreted as 0 in 10G mode
Signed-off-by: NQuan Nguyen <qnguyen@apm.com>
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds statistic counter for frames recovered from HW errata
10GE_8 and ENET_11:
"HW reports Length error for valid 64 byte frames with len <46 bytes".
Signed-off-by: NQuan Nguyen <qnguyen@apm.com>
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds workaround for HW errata 10GE_4:
"XGENET_ICM_ECM_DROP_COUNT_REG_0 reg not clear on read".
Signed-off-by: NQuan Nguyen <qnguyen@apm.com>
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds rx_overrun and tx_underrun ethtool statistic counters.
Signed-off-by: NQuan Nguyen <qnguyen@apm.com>
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds extended ethtool statistics support.
Signed-off-by: NQuan Nguyen <qnguyen@apm.com>
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch cleans up unused macros to improve readability.
Signed-off-by: NQuan Nguyen <qnguyen@apm.com>
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes the tx error counters and adds more rx error counters.
Signed-off-by: NQuan Nguyen <qnguyen@apm.com>
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 5944701d ("net: remove useless memset's in drivers get_stats64")
makes the pdata->stats redundant. This patch removes pdata->stats and
updates get_stats64() callback accordingly.
Signed-off-by: NQuan Nguyen <qnguyen@apm.com>
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch switches to use rgmii mdio mac access routines if available,
as they share the same HW.
Signed-off-by: NQuan Nguyen <qnguyen@apm.com>
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch,

- refactors mac access routine
- adds lock to protect mac indirect access
Signed-off-by: NQuan Nguyen <qnguyen@apm.com>
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch,

     - refactors mac read/write functions
     - adds lock to protect indirect mac access
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NQuan Nguyen <qnguyen@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull networking fixes from David Miller:

 1) Track alignment in BPF verifier so that legitimate programs won't be
    rejected on !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS architectures.

 2) Make tail calls work properly in arm64 BPF JIT, from Deniel
    Borkmann.

 3) Make the configuration and semantics Generic XDP make more sense and
    don't allow both generic XDP and a driver specific instance to be
    active at the same time. Also from Daniel.

 4) Don't crash on resume in xen-netfront, from Vitaly Kuznetsov.

 5) Fix use-after-free in VRF driver, from Gao Feng.

 6) Use netdev_alloc_skb_ip_align() to avoid unaligned IP headers in
    qca_spi driver, from Stefan Wahren.

 7) Always run cleanup routines in BPF samples when we get SIGTERM, from
    Andy Gospodarek.

 8) The mdio phy code should bring PHYs out of reset using the shared
    GPIO lines before invoking bus->reset(). From Florian Fainelli.

 9) Some USB descriptor access endian fixes in various drivers from
    Johan Hovold.

10) Handle PAUSE advertisements properly in mlx5 driver, from Gal
    Pressman.

11) Fix reversed test in mlx5e_setup_tc(), from Saeed Mahameed.

12) Cure netdev leak in AF_PACKET when using timestamping via control
    messages. From Douglas Caetano dos Santos.

13) netcp doesn't support HWTSTAMP_FILTER_ALl, reject it. From Miroslav
    Lichvar.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (52 commits)
  ldmvsw: stop the clean timer at beginning of remove
  ldmvsw: unregistering netdev before disable hardware
  net: netcp: fix check of requested timestamping filter
  ipv6: avoid dad-failures for addresses with NODAD
  qed: Fix uninitialized data in aRFS infrastructure
  mdio: mux: fix device_node_continue.cocci warnings
  net/packet: fix missing net_device reference release
  net/mlx4_core: Use min3 to select number of MSI-X vectors
  macvlan: Fix performance issues with vlan tagged packets
  net: stmmac: use correct pointer when printing normal descriptor ring
  net/mlx5: Use underlay QPN from the root name space
  net/mlx5e: IPoIB, Only support regular RQ for now
  net/mlx5e: Fix setup TC ndo
  net/mlx5e: Fix ethtool pause support and advertise reporting
  net/mlx5e: Use the correct pause values for ethtool advertising
  vmxnet3: ensure that adapter is in proper state during force_close
  sfc: revert changes to NIC revision numbers
  net: ch9200: add missing USB-descriptor endianness conversions
  net: irda: irda-usb: fix firmware name on big-endian hosts
  net: dsa: mv88e6xxx: add default case to switch
  ...

Pull cifs fixes from Steve French:
 "A set of minor cifs fixes"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  [CIFS] Minor cleanup of xattr query function
  fs: cifs: transport: Use time_after for time comparison
  SMB2: Fix share type handling
  cifs: cifsacl: Use a temporary ops variable to reduce code length
  Don't delay freeing mids when blocked on slow socket write of request
  CIFS: silence lockdep splat in cifs_relock_file()

Shannon Nelson says:

====================
ldmvsw: port removal stability

Under heavy reboot stress testing we found a couple of timing issues
when removing the device that could cause the kernel great heartburn,
addressed by these two patches.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Stop the clean timer earlier to be sure there's no asynchronous
interference while stopping the port.

Orabug: 25748241
Signed-off-by: NShannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When running LDom binding/unbinding test, kernel may panic
in ldmvsw_open(). It is more likely that because we're removing
the ldc connection before unregistering the netdev in vsw_port_remove(),
we set up a window of time where one process could be removing the
device while another trying to UP the device. This also sometimes causes
vio handshake error due to opening a device without closing it completely.
We should unregister the netdev before we disable the "hardware".

Orabug: 25980913, 25925306
Signed-off-by: NThomas Tai <thomas.tai@oracle.com>
Signed-off-by: NShannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver doesn't support timestamping of all received packets and
should return error when trying to enable the HWTSTAMP_FILTER_ALL
filter.

Cc: WingMan Kwok <w-kwok2@ti.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: NMiroslav Lichvar <mlichvar@redhat.com>
Acked-by: NRichard Cochran <richardcochran@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
Mellanox, mlx5 fixes 2017-05-12

This series contains some mlx5 fixes for net.
Please pull and let me know if there's any problem.

For -stable:
("net/mlx5e: Fix ethtool pause support and advertise reporting") kernels >= 4.8
("net/mlx5e: Use the correct pause values for ethtool advertising") kernels >= 4.8

v1->v2:
 Dropped statistics spinlock patch, it needs some extra work.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Every address gets added with TENTATIVE flag even for the addresses with
IFA_F_NODAD flag and dad-work is scheduled for them. During this DAD process
we realize it's an address with NODAD and complete the process without
sending any probe. However the TENTATIVE flags stays on the
address for sometime enough to cause misinterpretation when we receive a NS.
While processing NS, if the address has TENTATIVE flag, we mark it DADFAILED
and endup with an address that was originally configured as NODAD with
DADFAILED.

We can't avoid scheduling dad_work for addresses with NODAD but we can
avoid adding TENTATIVE flag to avoid this racy situation.
Signed-off-by: NMahesh Bandewar <maheshb@google.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>