Implement RxRPC slow-start, which is similar to RFC 5681 for TCP.  A
tracepoint is added to log the state of the congestion management algorithm
and the decisions it makes.

Notes:

 (1) Since we send fixed-size DATA packets (apart from the final packet in
     each phase), counters and calculations are in terms of packets rather
     than bytes.

 (2) The ACK packet carries the equivalent of TCP SACK.

 (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly
     suited to SACK of a small number of packets.  It seems that, almost
     inevitably, by the time three 'duplicate' ACKs have been seen, we have
     narrowed the loss down to one or two missing packets, and the
     FLIGHT_SIZE calculation ends up as 2.

 (4) In rxrpc_resend(), if there was no data that apparently needed
     retransmission, we transmit a PING ACK to ask the peer to tell us what
     its Rx window state is.
Signed-off-by: David Howells <dhowells@redhat.com>

If we've sent all the request data in a client call but haven't seen any
sign of the reply data yet, schedule an ACK to be sent to the server to
find out if the reply data got lost.

If the server hasn't yet hard-ACK'd the request data, we send a PING ACK to
demand a response to find out whether we need to retransmit.

If the server says it has received all of the data, we send an IDLE ACK to
tell the server that we haven't received anything in the receive phase as
yet.

To make this work, a non-immediate PING ACK must carry a delay.  I've chosen
the same as the IDLE ACK for the moment.
Signed-off-by: David Howells <dhowells@redhat.com>

Generate a summary of the Tx buffer packet state when an ACK is received
for use in a later patch that does congestion management.
Signed-off-by: David Howells <dhowells@redhat.com>

When determining the resend timer value, we have a value in nsec but the
timer is in jiffies which may be a million or more times more coarse.
nsecs_to_jiffies() rounds down - which means that the resend timeout
expressed as jiffies is very likely earlier than the one expressed as
nanoseconds from which it was derived.

The problem is that rxrpc_resend() gets triggered by the timer, but can't
then find anything to resend yet.  It sets the timer again - but gets
kicked off immediately again and again until the nanosecond-based expiry
time is reached and we actually retransmit.

Fix this by adding 1 to the jiffies-based resend_at value to counteract the
rounding and make sure that the timer happens after the nanosecond-based
expiry is passed.

Alternatives would be to adjust the timestamp on the packets to align
with the jiffie scale or to switch back to using jiffie-timestamps.
Signed-off-by: David Howells <dhowells@redhat.com>

Clear the ACK reason, ACK timer and resend timer when entering the client
reply phase when the first DATA packet is received.  New ACKs will be
proposed once the data is queued.

The resend timer is no longer relevant and we need to cancel ACKs scheduled
to probe for a lost reply.
Signed-off-by: David Howells <dhowells@redhat.com>

In a client call, include the serial number of the last DATA packet of the
reply in the final ACK.
Signed-off-by: David Howells <dhowells@redhat.com>

Send an immediate ACK if we fill in a hole in the buffer left by an
out-of-sequence packet.  This may allow the congestion management in the peer
to avoid a retransmission if packets got reordered on the wire.
Signed-off-by: David Howells <dhowells@redhat.com>

Send an ACK if we haven't sent one for the last two packets we've received.
This keeps the other end apprised of where we've got to - which is
important if they're doing slow-start.

We do this in recvmsg so that we can dispatch a packet directly without the
need to wake up the background thread.

This should possibly be made configurable in future.
Signed-off-by: David Howells <dhowells@redhat.com>

Typo's and spelling errors. Also remove old comment from staging era.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sunil Goutham says:

====================
BQL support and fix for a regression issue

These patches add byte queue limit support and also fixes a regression
issue introduced by commit
'net: thunderx: Use netdev's name for naming VF's interrupts'

Changes from v1:
- As suggested added 'Fixes' tag with commit id of previous commit
  which cuased issue.
- Also fixed the missing netdev_tx_reset_queue() function call in
  byte queue limits support patch.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds support for byte queue limits
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes a regression caused by previous commit
when irq name exceeds 20 byte array if interface's name
size is large.

Fixes: e4126213 ("net: thunderx: Use netdev's name for naming VF's interrupts")
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is an earlier check and return if err is non-zero, so
the check to see if it is zero is redundant in every iteration
of the loop and hence the check can be removed.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

fix typo in
Documentation/devicetree/bindings/net/mediatek-net.txt

Cc: devicetree@vger.kernel.org
Reported-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

add phy-mode "trgmii" to
Documentation/devicetree/bindings/net/ethernet.txt

Cc: devicetree@vger.kernel.org
Reported-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'rxrpc-rewrite-20160923' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

David Howells says:

====================
rxrpc: Bug fixes and tracepoints

Here are a bunch of bug fixes:

 (1) Need to set the timestamp on a Tx packet before queueing it to avoid
     trouble with the retransmission function.

 (2) Don't send an ACK at the end of the service reply transmission; it's
     the responsibility of the client to send an ACK to close the call.
     The service can resend the last DATA packet or send a PING ACK.

 (3) Wake sendmsg() on abnormal call termination.

 (4) Use ktime_add_ms() not ktime_add_ns() to add millisecond offsets.

 (5) Use before_eq() & co. to compare serial numbers (which may wrap).

 (6) Start the resend timer on DATA packet transmission.

 (7) Don't accidentally cancel a retransmission upon receiving a NACK.

 (8) Fix the call timer setting function to deal with timeouts that are now
     or past.

 (9) Don't use a flag to communicate the presence of the last packet in the
     Tx buffer from sendmsg to the input routines where ACK and DATA
     reception is handled.  The problem is that there's a window between
     queueing the last packet for transmission and setting the flag in
     which ACKs or reply DATA packets can arrive, causing apparent state
     machine violation issues.

     Instead use the annotation buffer to mark the last packet and pick up
     and set the flag in the input routines.

(10) Don't call the tx_ack tracepoint and don't allocate a serial number if
     someone else nicked the ACK we were about to transmit.

There are also new tracepoints and one altered tracepoint used to track
down the above bugs:

(11) Call timer tracepoint.

(12) Data Tx tracepoint (and adjustments to ACK tracepoint).

(13) Injected Rx packet loss tracepoint.

(14) Ack proposal tracepoint.

(15) Retransmission selection tracepoint.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
10GbE Intel Wired LAN Driver Updates 2016-09-23

This series contains updates to ixgbe and ixgbevf.

Emil provides several changes, first simplifies the logic for setting VLAN
filtering by checking the VMDQ flag and the old 82598 MAC, instead of
having to maintain a list of MAC types.  Then made two functions static
that are used only within the file, a by-product is sparse is now happy.
Added spinlocks to make sure that the MTU configuration is handled
properly.  Fixed an issue where when SR-IOV is enabled while the
ixgbevf driver is loaded would result in all mailbox requests being
rejected by ixgbe, so call ixgbe_sriov_reinit() before pci_enable_sriov()
to ensure mailbox requests are properly handled.

Mark resolves a NULL pointer issue by simply setting the read and write
*_ref_mdi pointers for x550em_a devices.  Then clearly indicates within
ethtool that all MACs support pause frames and made sure that the
advertising is set to the requested mode.  Fixed an issue where
MDIO_PRTAD_NONE was not being used consistently to indicate no PHY
address.

Alex fixes an issue, where the support for multiple queues when SR-IOV
is enabled was added but the support was not reported.  With that, fix
an issue where the hardware redirection table could support more queues
then the PF currently has when SR-IOV is enabled, so use the RSS mask to
trim off the bits that are not used.  Lastly, instead of limiting the
VFs if we do not use 4 queues for RSS in the PF, we can instead just limit
the RSS queues used to a power of 2.  We can now support use cases where
VFs are using more queues than the PF is currently using and can support
RSS if so desired.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2016-09-23

Only two patches this time:

1) Fix a comment reference to struct xfrm_replay_state_esn.
   From Richard Guy Briggs.

2) Convert xfrm_state_lookup to rcu, we don't need the
   xfrm_state_lock anymore in the input path.
   From Florian Westphal.

Please pull or let me know if there are problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
40GbE Intel Wired LAN Driver Updates 2016-09-22

This series contains updates to i40e and i40evf only.

Sridhar fixes link state event handling by updating the carrier and
starts/stops the Tx queues based on the link state notification from PF.

Brady fixes an issue where a user defined RSS hash key was not being
set because a user defined indirection table is not supplied when changing
the hash key, so if an indirection table is not supplied now, then a
default one is created and the hash key is correctly set.  Also fixed
an issue where when NPAR was enabled, we were still using pf->mac_seid
to perform the dump port query. Instead, go through the VSI to determine
the correct ID to use in either case.

Mitch provides one fix where a conditional return code was reversed, so
he does a "switheroo" to fix the issue.

Carolyn has two fixes, first fixes an issue in the virt channel code,
where a return code was not checked for NULL when applicable.  Second,
fixes an issue where we were byte swapping the port parameter, then
byte swapping it again in function execution.

Colin Ian King fixes a potential NULL pointer dereference.

Bimmy changes up i40evf_up_complete() to be void since it always returns
success anyways, which allows cleaning up of code which checked the
return code from this function.

Alex fixed an issue where the driver was incorrectly assuming that we
would always be pulling no more than 1 descriptor from each fragment.
So to correct this, we just need to make certain to test all the way to
the end of the fragments as it is possible for us to span 2 descriptors
in the block before us so we need to guarantee that even the last 6
descriptors have enough data to fill a full frame.

v2: dropped patches 1-3, 10 and 12 from the original series since Or
    Gerlitz pointed out several areas of improvement in the implementation
    of the VF Port representor netdev.  Sridhar is re-working the series
    for later submission.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Tariq Toukan says:

====================
mlx4 VF vlan protocol 802.1ad support

This patchset adds VF VLAN protocol 802.1ad support to the
mlx4 driver.
We extended the VF VLAN API with an additional parameter
for VLAN protocol, and kept 802.1Q as drivers' default.

We prepared a userspace support (ip link tool).
The patch will be submitted to the iproute2 mailing list.

The ip link tool VF VLAN protocol parameter is optional (default: 802.1Q).
A configuration command of VF VLAN that is used prior to this patchset
will result in same functionality as today's (VST with VLAN protocol 802.1Q).

The series generated against net-next commit:
688dc536 "Merge branch 'mlx4-next'"

All maintainers of the modified modules are in cc.

v3:
  Expand the UAPI to a nested list to support future use-cases.
  Use a more formal feature name.

v2:
  Drop patch 4 ("net/mlx4_core: Add an option to configure SVLAN TPID").
  Patch 1/5: Update commit log.
  2-3/5: Split patch 2 into two patches, to separate between changes
         done in mlx4_core and the ones done in mlx4_en.
  4-5/5: Split patch 3 into two patches, to separate between the
         addition of a protocol parameter and the actual implementation
	 in mlx4_en.
	 In addition, we implement a handshake mechanism so PF and VF
	 exchange their VST QinQ support capability.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Move the vf to VST 802.1ad mode (mlx4 VST QinQ mode) by setting vf vlan
protocol to 802.1ad.
VST 802.1ad mode in mlx4, is used for STAG strip/insertion by PF, while
the CTAG is set by the VF.
Read current vlan protocol as part of the vf configuration state.

Upon setting vf vlan protocol to 802.1ad, we use a mechanism of handshake
to verify that both the vf and the pf driver version support it.
The handshake uses the command QUERY_FUNC_CAP:
- The vf sets a pre-defined support bit in input modifier.
- A pf that supports the feature sends the request to the vf through a
  pre-defined field in the output mailbox.
- In case vf does not support the feature, the pf will fail the control
  command (in this case, IP link tool command to set the vf vlan
  protocol to 802.1ad).

No change in VST 802.1Q mode.
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Introduce new rtnl UAPI that exposes a list of vlans per VF, giving
the ability for user-space application to specify it for the VF, as an
option to support 802.1ad.
We adjusted IP Link tool to support this option.

For future use cases, the new UAPI supports multiple vlans. For now we
limit the list size to a single vlan in kernel.
Add IFLA_VF_VLAN_LIST in addition to IFLA_VF_VLAN to keep backward
compatibility with older versions of IP Link tool.

Add a vlan protocol parameter to the ndo_set_vf_vlan callback.
We kept 802.1Q as the drivers' default vlan protocol.
Suitable ip link tool command examples:
  Set vf vlan protocol 802.1ad:
    ip link set eth0 vf 1 vlan 100 proto 802.1ad
  Set vf to VST (802.1Q) mode:
    ip link set eth0 vf 1 vlan 100 proto 802.1Q
  Or by omitting the new parameter
    ip link set eth0 vf 1 vlan 100
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In Ethernet VF, disable vlan HW acceleration on VF
while it is set to VF vlan protocol 802.1ad mode.
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Check device capability to support VF vlan protocol 802.1ad mode.
Add vport attribute vlan protocol.
Init vport vlan protocol by default to 802.1Q.
Add update QP support for VF vlan protocol 802.1ad.
Add func capability vlan_offload_disable to disable all
vlan HW acceleration on VF while the VF is set to VF vlan protocol
802.1ad mode.
No change in VF vlan protocol 802.1Q (VST) mode.
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Separate QUERY_FUNC_CAP flags0 from QUERY_FUNC_CAP flags, as 'flags' is
already used for another set of flags in FUNC CAP, while phv bit should be
part of a different set of flags.
Remove QUERY_FUNC_CAP port_flags field, as it is not in use.

Fixes: 77fc29c4 ('net/mlx4_core: Preparations for 802.1ad VLAN support')
Fixes: 5cc914f1 ('mlx4_core: Added FW commands and their wrappers for supporting SRIOV')
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a tracepoint to log in rxrpc_resend() which packets will be
retransmitted.  Note that if a positive ACK comes in whilst we have dropped
the lock to retransmit another packet, the actual retransmission may not
happen, though some of the effects will (such as altering the congestion
management).
Signed-off-by: David Howells <dhowells@redhat.com>

Add a tracepoint to log proposed ACKs, including whether the proposal is
used to update a pending ACK or is discarded in favour of an easlier,
higher priority ACK.

Whilst we're at it, get rid of the rxrpc_acks() function and access the
name array directly.  We do, however, need to validate the ACK reason
number given to trace_rxrpc_rx_ack() to make sure we don't overrun the
array.
Signed-off-by: David Howells <dhowells@redhat.com>

Add a tracepoint to log received packets that get discarded due to Rx
packet loss.
Signed-off-by: David Howells <dhowells@redhat.com>

Add a tracepoint to log transmission of DATA packets (including loss
injection).

Adjust the ACK transmission tracepoint to include the packet serial number
and to line this up with the DATA transmission display.
Signed-off-by: David Howells <dhowells@redhat.com>

Add a tracepoint to log call timer initiation, setting and expiry.
Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc_send_call_packet() is invoking the tx_ack tracepoint before it checks
whether there's an ACK to transmit (another thread may jump in and transmit
it).

Fix this by only invoking the tracepoint if we get a valid ACK to transmit.

Further, only allocate a serial number if we're going to actually transmit
something.
Signed-off-by: David Howells <dhowells@redhat.com>

When the last packet of data to be transmitted on a call is queued, tx_top
is set and then the RXRPC_CALL_TX_LAST flag is set.  Unfortunately, this
leaves a race in the ACK processing side of things because the flag affects
the interpretation of tx_top and also allows us to start receiving reply
data before we've finished transmitting.

To fix this, make the following changes:

 (1) rxrpc_queue_packet() now sets a marker in the annotation buffer
     instead of setting the RXRPC_CALL_TX_LAST flag.

 (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the
     same context as the routines that use it.

 (3) rxrpc_end_tx_phase() is simplified to just shift the call state.
     The Tx window must have been rotated before calling to discard the
     last packet.

 (4) rxrpc_receiving_reply() is added to handle the arrival of the first
     DATA packet of a reply to a client call (which is an implicit ACK of
     the Tx phase).

 (5) The last part of rxrpc_input_ack() is reordered to perform Tx
     rotation, then soft-ACK application and then to end the phase if we've
     rotated the last packet.  In the event of a terminal ACK, the soft-ACK
     application will be skipped as nAcks should be 0.

 (6) rxrpc_input_ackall() now has to rotate as well as ending the phase.

In addition:

 (7) Alter the transmit tracepoint to log the rotation of the last packet.

 (8) Remove the no-longer relevant queue_reqack tracepoint note.  The
     ACK-REQUESTED packet header flag is now set as needed when we actually
     transmit the packet and may vary by retransmission.
Signed-off-by: David Howells <dhowells@redhat.com>

Fix the call timer in the following ways:

 (1) If call->resend_at or call->ack_at are before or equal to the current
     time, then ignore that timeout.

 (2) If call->expire_at is before or equal to the current time, then don't
     set the timer at all (possibly we should queue the call).

 (3) Don't skip modifying the timer if timer_pending() is true.  This
     indicates that the timer is working, not that it has expired and is
     running/waiting to run its expiry handler.

Also call rxrpc_set_timer() to start the call timer going rather than
calling add_timer().
Signed-off-by: David Howells <dhowells@redhat.com>

When rxrpc_input_soft_acks() is parsing the soft-ACKs from an ACK packet,
it updates the Tx packet annotations in the annotation buffer.  If a
soft-ACK is an ACK, then we overwrite unack'd, nak'd or to-be-retransmitted
states and that is fine; but if the soft-ACK is an NACK, we overwrite the
to-be-retransmitted with a nak - which isn't.

Instead, we need to let any scheduled retransmission stand if the packet
was NAK'd.

Note that we don't reissue a resend if the annotation is in the
to-be-retransmitted state because someone else must've scheduled the
resend already.
Signed-off-by: David Howells <dhowells@redhat.com>

This reverts commit c0c64c15.

There is no vif->ctrl_task member, so this change broke
the build.
Signed-off-by: David S. Miller <davem@davemloft.net>

When a DATA packet has its initial transmission, we may need to start or
adjust the resend timer.  Without this we end up relying on being sent a
NACK to initiate the resend.
Signed-off-by: David Howells <dhowells@redhat.com>

before_eq() and friends should be used to compare serial numbers (when not
checking for (non)equality) rather than casting to int, subtracting and
checking the result.
Signed-off-by: David Howells <dhowells@redhat.com>

Daniel Borkmann says:

====================
Few minor BPF helper improvements

Just a few minor improvements around BPF helpers, first one is a
fix but given this late stage and that it's not really a critical
one, I think net-next is just fine. For details please see the
individual patches.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a small helper that complements 36bbef52 ("bpf: direct packet
write and access for helpers for clsact progs") for invalidating the
current skb->hash after mangling on headers via direct packet write.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Same motivation as in commit 80b48c44 ("bpf: don't use raw processor
id in generic helper"), but this time for XDP typed programs. Thus, allow
for preemption checks when we have DEBUG_PREEMPT enabled, and otherwise
use the raw variant.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>