This is just common path code that belongs to ocelot_init,
it has nothing to do with a specific SoC/board instance.
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Allow these functions to be called from the .port_enable and
.port_disable callbacks of DSA.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We need a function for the DSA front-end that does none of the
net_device registration, but initializes the hardware ports.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The VSC7514 switch (Ocelot) is a 10-port device, while VSC9959 (Felix)
is 6-port. Therefore the VLAN filtering mask would be out of bounds when
calling for this new switch. Fix that.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Convert them into an implementation that can be called from DSA as well.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The ocelot and ocelot_port structures will be used by a new DSA driver,
so the ocelot_board.c file will have to allocate and work with a private
structure (ocelot_port_private), which embeds the generic struct
ocelot_port. This is because in DSA, at least one interface does not
have a net_device, and the DSA driver API does not interact with that
anyway.

The ocelot_port structure is equivalent to dsa_port, and ocelot to
dsa_switch. The members of ocelot_port which have an equivalent in
dsa_port (such as dp->vlan_filtering) have been moved to
ocelot_port_private.

We want to enforce the coding convention that "ocelot_port" refers to
the structure, and "port" refers to the integer index. One can retrieve
the structure at any time from ocelot->ports[port].

The patch is large but only contains variable renaming and mechanical
movement of fields from one structure to another.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The ocelot_port structure has a net_device embedded in it, which makes
it unsuitable for leaving it in the driver implementation functions.

Leave ocelot_flower.c untouched. In that file, ocelot_port is used as an
interface to the tc shared blocks. That will be addressed in the next
patch.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is needed so that the Felix DSA front-end can call the Ocelot
implementations.

The implementation of the "mc_disabled" switchdev attribute has also
been simplified by using the read-modify-write macro instead of
open-coding that operation.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is needed in order to present a simpler prototype to the DSA
front-end of ocelot.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

To be able to implement a DSA front-end over ocelot_fdb_add,
ocelot_fdb_del, ocelot_fdb_dump, these need to have a simple function
prototype that is independent of struct net_device, netlink skb, etc.

So rename the ndo ops of the ocelot driver into
ocelot_port_fdb_{add,del,dump}, and have them all call the abstract
implementations. At the same time, refactor ocelot_port_fdb_do_dump into
a function whose prototype is compatible with dsa_fdb_dump_cb_t, so that
the do_dump implementations can live together and be called by the
ocelot_fdb_dump through a function pointer.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We need an implementation of these functions that is agnostic to the
higher layer (switchdev or dsa).
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch transforms the ocelot_vlan_port_apply function ("apply
what?") into 3 standalone functions:

- ocelot_port_vlan_filtering
- ocelot_port_set_native_vlan
- ocelot_port_set_pvid

These functions have a prototype that is better aligned to the DSA API.

The function also had some static initialization (TPID, drop frames with
multicast source MAC) which was not being changed from any place, so
that was just moved to ocelot_probe_port (one of the 6 callers of
ocelot_vlan_port_apply).
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Iwan R Timmer says:

====================
net: dsa: mv88e6xxx: Add support for port mirroring

This patch series add support for port mirroring in the mv88e6xx switch driver.
The first patch changes the set_egress_port function to allow different egress
ports for egress and ingress traffic. The second patch adds the actual code for
port mirroring support.

Tested on a 88E6176 with:

tc qdisc add dev wan0 clsact
tc filter add dev wan0 ingress matchall skip_sw \
        action mirred egress mirror dev lan2
tc filter add dev wan0 egress matchall skip_sw \
        action mirred egress mirror dev lan3

Changes in v3

- Use enum for egress traffic direction
- Keep track of egress ports on mv88e6390
- Move booleans in struct for better structure packing

Changes in v2

- Support mirroring egress and ingress traffic to different ports
- Check for invalid configurations when multiple ports are mirrored
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for configuring port mirroring through the cls_matchall
classifier. We do a full ingress and/or egress capture towards a
capture port. It allows setting a different capture port for ingress
and egress traffic.

It keeps track of the mirrored ports and the destination ports to
prevent changes to the capture port while other ports are being
mirrored.
Signed-off-by: Iwan R Timmer <irtimmer@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Separate the configuration of the egress and ingress monitor port.
This allows the port mirror functionality to do ingress and egress
port mirroring to separate ports.
Signed-off-by: Iwan R Timmer <irtimmer@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

The LAN743x Ethernet controller provides two independent PTP event
channels. Each one can be used to generate a periodic output from
the PTP clock. The output can be routed to any one of the available
GPIO pins on the device.

The PTP clock API can now be used to:
- select any LAN743x GPIO pin to function as a periodic output
- select either LAN743x PTP event channel to generate the output

The LAN7430 has 4 GPIO pins that are multiplexed with its internal
PHY LED control signals. A pin assigned to the LED control function
will be assigned to the GPIO function if selected for PTP periodic
output.
Signed-off-by: John Efstathiades <john.efstathiades@pebblebay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Vladimir Oltean says:

====================
Unlock new potential in SJA1105 with PTP system timestamping

The SJA1105 being an automotive switch means it is designed to live in a
set-and-forget environment, far from the configure-at-runtime nature of
Linux. Frequently resetting the switch to change its static config means
it loses track of its PTP time, which is not good.

This patch series implements PTP system timestamping for this switch
(using the API introduced for SPI here:
https://www.mail-archive.com/netdev@vger.kernel.org/msg316725.html),
adding the following benefits to the driver:
- When under control of a user space PTP servo loop (ptp4l, phc2sys),
  the loss of sync during a switch reset is much more manageable, and
  the switch still remains in the s2 (locked servo) state.
- When synchronizing the switch using the software technique (based on
  reading clock A and writing the value to clock B, as opposed to
  relying on hardware timestamping), e.g. by using phc2sys, the sync
  accuracy is vastly improved due to the fact that the actual switch PTP
  time can now be more precisely correlated with something of better
  precision (CLOCK_REALTIME). The issue is that SPI transfers are
  inherently bad for measuring time with low jitter, but the newly
  introduced API aims to alleviate that issue somewhat.

This series is also a requirement for a future patch set that adds full
time-aware scheduling offload support for the switch.
====================
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The purpose here is to avoid ptp4l fail due to this condition:

  timed out while polling for tx timestamp
  increasing tx_timestamp_timeout may correct this issue, but it is likely caused by a driver bug
  port 1: send peer delay request failed

So either reset the switch before the management frame was sent, or
after it was timestamped as well, but not in the middle.

The condition may arise either due to a true timeout (i.e. because
re-uploading the static config takes time), or due to the TX timestamp
actually getting lost due to reset. For the former we can increase
tx_timestamp_timeout in userspace, for the latter we need this patch.

Locking all traffic during switch reset does not make sense at all,
though. Forcing all CPU-originated traffic to potentially block waiting
for a sleepable context to send > 800 bytes over SPI is not a good idea.
Flows that are autonomously forwarded by the switch will get dropped
anyway during switch reset no matter what. So just let all other
CPU-originated traffic be dropped as well.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The PTP time of the switch is not preserved when uploading a new static
configuration. Work around this hardware oddity by reading its PTP time
before a static config upload, and restoring it afterwards.

Static config changes are expected to occur at runtime even in scenarios
directly related to PTP, i.e. the Time-Aware Scheduler of the switch is
programmed in this way.

Perhaps the larger implication of this patch is that the PTP .gettimex64
and .settime functions need to be exposed to sja1105_main.c, where the
PTP lock needs to be held during this entire process. So their core
implementation needs to move to some common functions which get exposed
in sja1105_ptp.h.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Through the PTP_SYS_OFFSET_EXTENDED ioctl, it is possible for userspace
applications (i.e. phc2sys) to compensate for the delays incurred while
reading the PHC's time.

The task itself of taking the software timestamp is delegated to the SPI
subsystem, through the newly introduced API in struct spi_transfer. The
goal is to cross-timestamp I/O operations on the switch's PTP clock with
values in the local system clock (CLOCK_REALTIME). For that we need to
understand a bit of the hardware internals.

The 'read PTP time' message is a 12 byte structure, first 4 bytes of
which represent the SPI header, and the last 8 bytes represent the
64-bit PTP time. The switch itself starts processing the command
immediately after receiving the last bit of the address, i.e. at the
middle of byte 3 (last byte of header). The PTP time is shadowed to a
buffer register in the switch, and retrieved atomically during the
subsequent SPI frames.

A similar thing goes on for the 'write PTP time' message, although in
that case the switch waits until the 64-bit PTP time becomes fully
available before taking any action. So the byte that needs to be
software-timestamped is byte 11 (last) of the transfer.

The patch creates a common (and local) sja1105_xfer implementation for
the SPI I/O, and offers 3 front-ends:

- sja1105_xfer_u32 and sja1105_xfer_u64: these are capable of optionally
  requesting a PTP timestamp

- sja1105_xfer_buf: this is for large transfers (e.g. the static config
  buffer) and other misc data, and there is no point in giving
  timestamping capabilities to this.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Heiner Kallweit says:

====================
r8169: improve PHY configuration

This series adds helpers to improve and simplify the PHY
configuration on various network chip versions.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

rtl8168c_4_hw_phy_config() duplicates rtl8168c_3_hw_phy_config(),
so we can remove the function.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Certain integrated PHY's from RTL8168d support extended pages. On page
0x0007 the number of the extended page is written to register 0x1e,
then the registers on the extended page can be accessed. Add a helper
for this to improve readability and simplify the code.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use the phylib MDIO access functions in more places to simplify
the code.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Integrated PHY's from RTL8168d support an indirect access method for
PHY parameters. On page 0x0005 parameter number is written to register
0x05, then the parameter can be accessed via register 0x06.
Add a helper for this to improve readability and simplify the code.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Integrated PHY's from RTL8168g support an indirect access method for
PHY parameters. On page 0x0a43 parameter number is written to register
0x13, then the parameter can be accessed via register 0x14.
Add a helper for this to improve readability and simplify the code.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The current upstream interface is an all-or-nothing, which is
sub-optimal for future changes, as it doesn't allow the upstream driver
to prepare for the SFP module becoming available, as it is at boot.

Switch to a find-sfp-bus, add-upstream, del-upstream, put-sfp-bus
interface structure instead, which allows the upstream driver to
prepare for a module being available as soon as add-upstream is called.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

One conflict in the BPF samples Makefile, some fixes in 'net' whilst
we were converting over to Makefile.target rules in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull networking fixes from David Miller:

 1) BPF sample build fixes from Björn Töpel

 2) Fix powerpc bpf tail call implementation, from Eric Dumazet.

 3) DCCP leaks jiffies on the wire, fix also from Eric Dumazet.

 4) Fix crash in ebtables when using dnat target, from Florian Westphal.

 5) Fix port disable handling whne removing bcm_sf2 driver, from Florian
    Fainelli.

 6) Fix kTLS sk_msg trim on fallback to copy mode, from Jakub Kicinski.

 7) Various KCSAN fixes all over the networking, from Eric Dumazet.

 8) Memory leaks in mlx5 driver, from Alex Vesker.

 9) SMC interface refcounting fix, from Ursula Braun.

10) TSO descriptor handling fixes in stmmac driver, from Jose Abreu.

11) Add a TX lock to synchonize the kTLS TX path properly with crypto
    operations. From Jakub Kicinski.

12) Sock refcount during shutdown fix in vsock/virtio code, from Stefano
    Garzarella.

13) Infinite loop in Intel ice driver, from Colin Ian King.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (108 commits)
  ixgbe: need_wakeup flag might not be set for Tx
  i40e: need_wakeup flag might not be set for Tx
  igb/igc: use ktime accessors for skb->tstamp
  i40e: Fix for ethtool -m issue on X722 NIC
  iavf: initialize ITRN registers with correct values
  ice: fix potential infinite loop because loop counter being too small
  qede: fix NULL pointer deref in __qede_remove()
  net: fix data-race in neigh_event_send()
  vsock/virtio: fix sock refcnt holding during the shutdown
  net: ethernet: octeon_mgmt: Account for second possible VLAN header
  mac80211: fix station inactive_time shortly after boot
  net/fq_impl: Switch to kvmalloc() for memory allocation
  mac80211: fix ieee80211_txq_setup_flows() failure path
  ipv4: Fix table id reference in fib_sync_down_addr
  ipv6: fixes rt6_probe() and fib6_nh->last_probe init
  net: hns: Fix the stray netpoll locks causing deadlock in NAPI path
  net: usb: qmi_wwan: add support for DW5821e with eSIM support
  CDC-NCM: handle incomplete transfer of MTU
  nfc: netlink: fix double device reference drop
  NFC: st21nfca: fix double free
  ...

Pull block fixes from Jens Axboe:

 - Two NVMe device removal crash fixes, and a compat fixup for for an
   ioctl that was introduced in this release (Anton, Charles, Max - via
   Keith)

 - Missing error path mutex unlock for drbd (Dan)

 - cgroup writeback fixup on dead memcg (Tejun)

 - blkcg online stats print fix (Tejun)

* tag 'for-linus-2019-11-08' of git://git.kernel.dk/linux-block:
  cgroup,writeback: don't switch wbs immediately on dead wbs if the memcg is dead
  block: drbd: remove a stray unlock in __drbd_send_protocol()
  blkcg: make blkcg_print_stat() print stats only for online blkgs
  nvme: change nvme_passthru_cmd64 to explicitly mark rsvd
  nvme-multipath: fix crash in nvme_mpath_clear_ctrl_paths
  nvme-rdma: fix a segmentation fault during module unload

Jeff Kirsher says:

====================
Intel Wired LAN Driver Fixes 2019-11-08

This series contains fixes to igb, igc, ixgbe, i40e, iavf and ice
drivers.

Colin Ian King fixes a potentially wrap-around counter in a for-loop.

Nick fixes the default ITR values for the iavf driver to 50 usecs
interval.

Arkadiusz fixes 'ethtool -m' for X722 devices where the correct value
cannot be obtained from the firmware, so add X722 to the check to ensure
the wrong value is not returned.

Jake fixes igb and igc drivers in their implementation of launch time
support by declaring skb->tstamp value as ktime_t instead of s64.

Magnus fixes ixgbe and i40e where the need_wakeup flag for transmit may
not be set for AF_XDP sockets that are only used to send packets.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The need_wakeup flag for Tx might not be set for AF_XDP sockets that
are only used to send packets. This happens if there is at least one
outstanding packet that has not been completed by the hardware and we
get that corresponding completion (which will not generate an
interrupt since interrupts are disabled in the napi poll loop) between
the time we stopped processing the Tx completions and interrupts are
enabled again. In this case, the need_wakeup flag will have been
cleared at the end of the Tx completion processing as we believe we
will get an interrupt from the outstanding completion at a later point
in time. But if this completion interrupt occurs before interrupts
are enable, we lose it and should at that point really have set the
need_wakeup flag since there are no more outstanding completions that
can generate an interrupt to continue the processing. When this
happens, user space will see a Tx queue need_wakeup of 0 and skip
issuing a syscall, which means will never get into the Tx processing
again and we have a deadlock.

This patch introduces a quick fix for this issue by just setting the
need_wakeup flag for Tx to 1 all the time. I am working on a proper
fix for this that will toggle the flag appropriately, but it is more
challenging than I anticipated and I am afraid that this patch will
not be completed before the merge window closes, therefore this easier
fix for now. This fix has a negative performance impact in the range
of 0% to 4%. Towards the higher end of the scale if you have driver
and application on the same core and issue a lot of packets, and
towards no negative impact if you use two cores, lower transmission
speeds and/or a workload that also receives packets.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The need_wakeup flag for Tx might not be set for AF_XDP sockets that
are only used to send packets. This happens if there is at least one
outstanding packet that has not been completed by the hardware and we
get that corresponding completion (which will not generate an
interrupt since interrupts are disabled in the napi poll loop) between
the time we stopped processing the Tx completions and interrupts are
enabled again. In this case, the need_wakeup flag will have been
cleared at the end of the Tx completion processing as we believe we
will get an interrupt from the outstanding completion at a later point
in time. But if this completion interrupt occurs before interrupts
are enable, we lose it and should at that point really have set the
need_wakeup flag since there are no more outstanding completions that
can generate an interrupt to continue the processing. When this
happens, user space will see a Tx queue need_wakeup of 0 and skip
issuing a syscall, which means will never get into the Tx processing
again and we have a deadlock.

This patch introduces a quick fix for this issue by just setting the
need_wakeup flag for Tx to 1 all the time. I am working on a proper
fix for this that will toggle the flag appropriately, but it is more
challenging than I anticipated and I am afraid that this patch will
not be completed before the merge window closes, therefore this easier
fix for now. This fix has a negative performance impact in the range
of 0% to 4%. Towards the higher end of the scale if you have driver
and application on the same core and issue a lot of packets, and
towards no negative impact if you use two cores, lower transmission
speeds and/or a workload that also receives packets.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

When implementing launch time support in the igb and igc drivers, the
skb->tstamp value is assumed to be a s64, but it's declared as a ktime_t
value.

Although ktime_t is typedef'd to s64 it wasn't always, and the kernel
provides accessors for ktime_t values.

Use the ktime_to_timespec64 and ktime_set accessors instead of directly
assuming that the variable is always an s64.

This improves portability if the code is ever moved to another kernel
version, or if the definition of ktime_t ever changes again in the
future.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch contains fix for a problem with command:
'ethtool -m <dev>'
which breaks functionality of:
'ethtool <dev>'
when called on X722 NIC

Disallowed update of link phy_types on X722 NIC
Currently correct value cannot be obtained from FW
Previously wrong value returned by FW was used and was
a root cause for incorrect output of 'ethtool <dev>' command
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Since commit 92418fb1 ("i40e/i40evf: Use usec value instead of reg
value for ITR defines") the driver tracks the interrupt throttling
intervals in single usec units, although the actual ITRN registers are
programmed in 2 usec units. Most register programming flows in the driver
correctly handle the conversion, although it is currently not applied when
the registers are initialized to their default values. Most of the time
this doesn't present a problem since the default values are usually
immediately overwritten through the standard adaptive throttling mechanism,
or updated manually by the user, but if adaptive throttling is disabled and
the interval values are left alone then the incorrect value will persist.

Since the intended default interval of 50 usecs (vs. 100 usecs as
programmed) performs better for most traffic workloads, this can lead to
performance regressions.

This patch adds the correct conversion when writing the initial values to
the ITRN registers.
Signed-off-by: Nicholas Nunley <nicholas.d.nunley@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Currently the for-loop counter i is a u8 however it is being checked
against a maximum value hw->num_tx_sched_layers which is a u16. Hence
there is a potential wrap-around of counter i back to zero if
hw->num_tx_sched_layers is greater than 255.  Fix this by making i
a u16.

Addresses-Coverity: ("Infinite loop")
Fixes: b36c598c ("ice: Updates to Tx scheduler code")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Xin Long says:

====================
sctp: update from rfc7829

SCTP-PF was implemented based on a Internet-Draft in 2012:

  https://tools.ietf.org/html/draft-nishida-tsvwg-sctp-failover-05

It's been updated quite a few by rfc7829 in 2016.

This patchset adds the following features:

  1. add SCTP_ADDR_POTENTIALLY_FAILED notification
  2. add pf_expose per netns/sock/asoc
  3. add SCTP_EXPOSE_POTENTIALLY_FAILED_STATE sockopt
  4. add ps_retrans per netns/sock/asoc/transport
     (Primary Path Switchover)
  5. add spt_pathcpthld for SCTP_PEER_ADDR_THLDS sockopt

v1->v2:
  - See Patch 2/5 and Patch 5/5.
v2->v3:
  - See Patch 1/5, 2/5 and 3/5.
v3->v4:
  - See Patch 1/5, 2/5, 3/5 and 4/5.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Section 7.2 of rfc7829: "Peer Address Thresholds (SCTP_PEER_ADDR_THLDS)
Socket Option" extends 'struct sctp_paddrthlds' with 'spt_pathcpthld'
added to allow a user to change ps_retrans per sock/asoc/transport, as
other 2 paddrthlds: pf_retrans, pathmaxrxt.

Note: to not break the user's program, here to support pf_retrans dump
and setting by adding a new sockopt SCTP_PEER_ADDR_THLDS_V2, and a new
structure sctp_paddrthlds_v2 instead of extending sctp_paddrthlds.

Also, when setting ps_retrans, the value is not allowed to be greater
than pf_retrans.

v1->v2:
  - use SCTP_PEER_ADDR_THLDS_V2 to set/get pf_retrans instead,
    as Marcelo and David Laight suggested.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is a new feature defined in section 5 of rfc7829: "Primary Path
Switchover". By introducing a new tunable parameter:

  Primary.Switchover.Max.Retrans (PSMR)

The primary path will be changed to another active path when the path
error counter on the old primary path exceeds PSMR, so that "the SCTP
sender is allowed to continue data transmission on a new working path
even when the old primary destination address becomes active again".

This patch is to add this tunable parameter, 'ps_retrans' per netns,
sock, asoc and transport. It also allows a user to change ps_retrans
per netns by sysctl, and ps_retrans per sock/asoc/transport will be
initialized with it.

The check will be done in sctp_do_8_2_transport_strike() when this
feature is enabled.

Note this feature is disabled by initializing 'ps_retrans' per netns
as 0xffff by default, and its value can't be less than 'pf_retrans'
when changing by sysctl.

v3->v4:
  - add define SCTP_PS_RETRANS_MAX 0xffff, and use it on extra2 of
    sysctl 'ps_retrans'.
  - add a new entry for ps_retrans on ip-sysctl.txt.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>