UDP busy polling is restricted to connected UDP sockets.

This is because sk_busy_loop() only takes care of one NAPI context.

There are cases where it could be extended.

1) Some hosts receive traffic on a single NIC, with one RX queue.

2) Some applications use SO_REUSEPORT and associated BPF filter
   to split the incoming traffic on one UDP socket per RX
queue/thread/cpu

3) Some UDP sockets are used to send/receive traffic for one flow, but
they do not bother with connect()

This patch records the napi_id of first received skb, giving more
reach to busy polling.

Tested:

lpaa23:~# echo 70 >/proc/sys/net/core/busy_read
lpaa24:~# echo 70 >/proc/sys/net/core/busy_read

lpaa23:~# for f in `seq 1 10`; do ./super_netperf 1 -H lpaa24 -t UDP_RR -l 5; done

Before patch :
   27867   28870   37324   41060   41215
   36764   36838   44455   41282   43843
After patch :
   73920   73213   70147   74845   71697
   68315   68028   75219   70082   73707
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sowmini Varadhan says:

====================
RDS: TCP: HA/Failover fixes

This series contains a set of fixes for bugs exposed when
we ran the following in a loop between a test machine pair:

 while (1); do
   # modprobe rds-tcp on test nodes
   # run rds-stress in bi-dir mode between test machine pair
   # modprobe -r rds-tcp on test nodes
 done

rds-stress in bi-dir mode will cause both nodes to initiate
RDS-TCP connections at almost the same instant, exposing the
bugs fixed in this series.

Without the fixes, rds-stress reports sporadic packet drops,
and packets arriving out of sequence. After the fixes,we have
been able to run the  test overnight, without any issues.

Each patch has a detailed description of the root-cause fixed
by the patch.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

When 2 RDS peers initiate an RDS-TCP connection simultaneously,
there is a potential for "duelling syns" on either/both sides.
See commit 241b2719 ("RDS-TCP: Reset tcp callbacks if re-using an
outgoing socket in rds_tcp_accept_one()") for a description of this
condition, and the arbitration logic which ensures that the
numerically large IP address in the TCP connection is bound to the
RDS_TCP_PORT ("canonical ordering").

The rds_connection should not be marked as RDS_CONN_UP until the
arbitration logic has converged for the following reason. The sender
may start transmitting RDS datagrams as soon as RDS_CONN_UP is set,
and since the sender removes all datagrams from the rds_connection's
cp_retrans queue based on TCP acks. If the TCP ack was sent from
a tcp socket that got reset as part of duel aribitration (but
before data was delivered to the receivers RDS socket layer),
the sender may end up prematurely freeing the datagram, and
the datagram is no longer reliably deliverable.

This patch remedies that condition by making sure that, upon
receipt of 3WH completion state change notification of TCP_ESTABLISHED
in rds_tcp_state_change, we mark the rds_connection as RDS_CONN_UP
if, and only if, the IP addresses and ports for the connection are
canonically ordered. In all other cases, rds_tcp_state_change will
force an rds_conn_path_drop(), and rds_queue_reconnect() on
both peers will restart the connection to ensure canonical ordering.

A side-effect of enforcing this condition in rds_tcp_state_change()
is that rds_tcp_accept_one_path() can now be refactored for simplicity.
It is also no longer possible to encounter an RDS_CONN_UP connection in
the arbitration logic in rds_tcp_accept_one().
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The RDS transport has to be able to distinguish between
two types of failure events:
(a) when the transport fails (e.g., TCP connection reset)
    but the RDS socket/connection layer on both sides stays
    the same
(b) when the peer's RDS layer itself resets (e.g., due to module
    reload or machine reboot at the peer)
In case (a) both sides must reconnect and continue the RDS messaging
without any message loss or disruption to the message sequence numbers,
and this is achieved by rds_send_path_reset().

In case (b) we should reset all rds_connection state to the
new incarnation of the peer. Examples of state that needs to
be reset are next expected rx sequence number from, or messages to be
retransmitted to, the new incarnation of the peer.

To achieve this, the RDS handshake probe added as part of
commit 5916e2c1 ("RDS: TCP: Enable multipath RDS for TCP")
is enhanced so that sender and receiver of the RDS ping-probe
will add a generation number as part of the RDS_EXTHDR_GEN_NUM
extension header. Each peer stores local and remote generation
numbers as part of each rds_connection. Changes in generation
number will be detected via incoming handshake probe ping
request or response and will allow the receiver to reset rds_connection
state.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As noted in rds_recv_incoming() sequence numbers on data packets
can decreas for the failover case, and the Rx path is equipped
to recover from this, if the RDS_FLAG_RETRANSMITTED is set
on the rds header of an incoming message with a suspect sequence
number.

The RDS_FLAG_RETRANSMITTED is predicated on the RDS_FLAG_RETRANSMITTED
flag in the rds_message, so make sure the flag is set on messages
queued for retransmission.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As sugested by Joe Perches, we could replace all
if (netif_msg_type(priv)) dev_xxx(priv->devices, ...)
by the simpler macro netif_xxx(priv, hw, priv->dev, ...)
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some printing have the function name hardcoded.
It is better to use __func__ instead.
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The stmmac driver use lots of pr_xxx functions to print information.
This is bad since we cannot know which device logs the information.
(moreover if two stmmac device are present)

Furthermore, it seems that it assumes wrongly that all logs will always
be subsequent by using a dev_xxx then some indented pr_xxx like this:
kernel: sun7i-dwmac 1c50000.ethernet: no reset control found
kernel:  Ring mode enabled
kernel:  No HW DMA feature register supported
kernel:  Normal descriptors
kernel:  TX Checksum insertion supported

So this patch replace all pr_xxx by their netdev_xxx counterpart.
Excepts for some printing where netdev "cause" unpretty output like:
sun7i-dwmac 1c50000.ethernet (unnamed net_device) (uninitialized): no reset control found
In those case, I keep dev_xxx.

In the same time I remove some "stmmac:" print since
this will be a duplicate with that dev_xxx displays.
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When I wrote sch_fq.c, hash_ptr() on 64bit arches was awful,
and I chose hash_32().

Linus Torvalds and George Spelvin fixed this issue, so we can
use hash_ptr() to get more entropy on 64bit arches with Terabytes
of memory, and avoid the cast games.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Calling napi_hash_del() after netif_napi_del() is pointless.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is no need calling napi_hash_del()+synchronize_rcu() before
calling netif_napi_del()

netif_napi_del() does this already.

Using napi_hash_del() in a driver is useful only when dealing with
a batch of NAPI structures, so that a single synchronize_rcu() can
be used. mlx4_en_deactivate_cq() is deactivating a single NAPI.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jiri Pirko says:

====================
mlxsw: Introduce support for I2C bus

Vadim says:

This patchset adds I2C access support for SwitchX, SwitchX2, SwitchIB,
SwitchIB2 and Spectrum silicones.

It contains:
 - Small changes in mlxsw core code, needed for I2C bus support;
 - I2C driver, which obtains I2C input/output mailboxes setting and
   provides command interface implementation.
 - Minimal driver, which works on top of I2C driver and allows running
   of mlxsw command interface over I2C bus;

Use case:
On system, which does not have PCI to ASIC (BMC), hwmon functionality
(sensors, pwm, tacho) will be available through I2C.

Usage (manual probing):
echo mlxsw_minimal 0x48 > /sys/bus/i2c/devices/i2c-2/new_device

Sysfs interface:
/sys/bus/i2c/devices/2-0048/hwmon/hwmon5/pwm1
/sys/bus/i2c/devices/2-0048/hwmon/hwmon5/temp1_input
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add I2C access support for Mellanox ASICs:
- Virtual Protocol Interconnect switches SwitchX, SwitchX2,
  providing InfiniBand, Ethernet and Fibre Channel connectivity;
- Infiniband switches SwitchIB, SwitchIB2:
- Ethernet switch Spectrum.

Example of probing activation:
echo mlxsw_minimal 0x48 > /sys/bus/i2c/devices/i2c-2/new_device
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We are going to add a minimal driver on top of the mlxsw core
infrastructure, which will be mainly used for hardware monitoring in
Baseboard management controller (BMC) installations.

Unlike the switch drivers (e.g., spectrum, switchx2), this driver does not
initialize the ASIC and therefore doesn't need to implement the init() and
fini() methods in its 'mlxsw_driver' struct.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add I2C bus implementation for Mellanox Technologies Switch ASICs.
This includes command interface implementation using input / out mailboxes,
whose location is retrieved from the firmware during probe time.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The mlxsw core infrastructure currently assumes that communication with
the ASIC is always possible using Ethernet management datagrams (EMADs),
but this is only possible when the PCI bus is used.

The bus capability flag is added to indicate EMAD support and make core
initialize EMAD communication only when it's set. Otherwise, register
access is done using command interface.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

knav_queue_open always returns an ERR_PTR value, never NULL.  This can be
confirmed by unfolding the function calls and conforms to the function's
documentation.  Thus, replace IS_ERR_OR_NULL by IS_ERR in error checks.

The change is made using the following semantic patch:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x;
statement S;
@@

x = knav_queue_open(...);
if (
-   IS_ERR_OR_NULL
+   IS_ERR
    (x)) S
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now sctp transport rhashtable uses hash(lport, dport, daddr) as the key
to hash a node to one chain. If in one host thousands of assocs connect
to one server with the same lport and different laddrs (although it's
not a normal case), all the transports would be hashed into the same
chain.

It may cause to keep returning -EBUSY when inserting a new node, as the
chain is too long and sctp inserts a transport node in a loop, which
could even lead to system hangs there.

The new rhlist interface works for this case that there are many nodes
with the same key in one chain. It puts them into a list then makes this
list be as a node of the chain.

This patch is to replace rhashtable_ interface with rhltable_ interface.
Since a chain would not be too long and it would not return -EBUSY with
this fix when inserting a node, the reinsert loop is also removed here.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Michael Chan says:

====================
bnxt_en: Updates.

New firmware spec. update, autoneg update, and UDP RSS support.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

To display and modify the RSS hash.
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The newer chips have proper support for 4-tuple UDP RSS.
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

On some dual port NICs, the speed setting on one port can affect the
available speed on the other port.  Add logic to detect these changes
and adjust the advertised speed settings when necessary.
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use the new FORCE_LINK_DWN bit to shutdown link during close.
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Callers of netpoll_poll_lock() own NAPI_STATE_SCHED

Callers of netpoll_poll_unlock() have BH blocked between
the NAPI_STATE_SCHED being cleared and poll_lock is released.

We can avoid the spinlock which has no contention, and use cmpxchg()
on poll_owner which we need to set anyway.

This removes a possible lockdep violation after the cited commit,
since sk_busy_loop() re-enables BH before calling busy_poll_stop()

Fixes: 217f6974 ("net: busy-poll: allow preemption in sk_busy_loop()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

New Cadence GEM hardware support Large Segment Offload (LSO):
TCP segmentation offload (TSO) as well as UDP fragmentation
offload (UFO). Support for those features was added to the driver.
Signed-off-by: David S. Miller <davem@davemloft.net>

The netdev->real_num_rx_queues setting is only available if CONFIG_SYSFS
is enabled, so we now get a build failure when that is turned off:

netronome/nfp/nfp_net_common.c: In function 'nfp_net_ring_swap_enable':
netronome/nfp/nfp_net_common.c:2489:18: error: 'struct net_device' has no member named 'real_num_rx_queues'; did you mean 'real_num_tx_queues'?

As far as I can tell, the check here is only used as an optimization that
we can skip in order to fix the compilation. If sysfs is disabled,
the following netif_set_real_num_rx_queues() has no effect.

Fixes: 164d1e9e ("nfp: add support for ethtool .set_channels")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Calling napi_hash_del() after netif_napi_del() is pointless.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Edward Cree <ecree@solarflare.com>
Cc: Bert Kenward <bkenward@solarflare.com>
Acked-by: Bert Kenward <bkenward@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch changes the lwtunnel_headroom() function which is called
in ipv4_mtu() and ip6_mtu(), to also return the correct headroom
value when the lwtunnel state is OUTPUT_REDIRECT.

This patch enables e.g. SR-IPv6 encapsulations to work without
manually setting the route mtu.
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

The recent merge commit bb598c1b ("Merge
git://git.kernel.org/pub/scm/linux/kernel/git/davem/net") would cause
the FIB abort warning to fire whenever we flush the FIB tables - either
during module removal or actual abort.

Move it back to its rightful location in the FIB abort function.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The SPEED_UNFORCED indicates the MAC & PHY should perform
auto-negotiation to determine a speed which works. If this is called
for, don't set the force bit. If it is set, the MAC actually does
10Gbps, why the internal PHYs don't support.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tom Lendacky says:

====================
amd-xgbe: AMD XGBE driver updates 2016-11-15

This patch series addresses some minor issues found in the recently
accepted patch series for the AMD XGBE driver.

The following fixes are included in this driver update series:

- Fix a possibly uninitialized variable in the debugfs support
- Fix the GPIO pin number constraint check

This patch series is based on net-next.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The GPIO support in the hardware allows for up to 16 GPIO pins, enumerated
from 0 to 15.  The driver uses the wrong value (16) to validate the GPIO
pin range in the routines to set and clear the GPIO output pins.  Update
the code to use the correct value (15).
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The debugfs support in the driver uses a common routine to write the
debugfs values. In this routine, if the input file position is non-zero
then the write routine will not return an error and an output parameter
will not have been set. Because an error isn't returned an uninitialized
value will be written into a register.

Fix the common write routine to return an error if the input file position
is non-zero, which will propagate back to the caller.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Florian Fainelli says:

====================
net: Implenent ethtool::nway_reset for a few drivers

This patch series depends on "net: phy: Centralize auto-negotation restart"
since it provides phy_ethtool_nway_reset as a helper function.

The drivers here already support PHYLIB, so there really is no reason why
restarting auto-negotiation would not be possible with these.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Implement ethtool::nway_reset using phy_ethtool_nway_reset. We are
already using dev->phydev all over the place so this comes for free.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Implement ethtool::nway_reset using phy_ethtool_nway_reset. We are
already using dev->phydev all over the place so this comes for free.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Implement ethtool::nway_reset using phy_ethtool_nway_reset. We are
already using dev->phydev all over the place so this comes for free.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Implement ethtool::nway_reset using phy_ethtool_nway_reset. We are
already using dev->phydev all over the place so this comes for free.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Utilize the generic phy_ethtool_nway_reset() helper function to
implement an autonegotiation restart.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Eric Dumazet says:

====================
net: busy-poll: allow preemption and other optimizations

It is time to have preemption points in sk_busy_loop() and improve
its scalability.

Also napi_complete() and friends can tell drivers when it is safe to
not re-enable device interrupts, saving some overhead under
high busy polling.

mlx4 and bnx2x are changed accordingly, to show how this busy polling
status can be exploited by drivers.

Next steps will implement Zach Brown suggestion, where NAPI polling
would be enabled all the time for some chosen queues.
This is needed for efficient epoll() support anyway.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>