We refer to a TC NIC rule that involves forwarding as "hairpin".
Hairpin queues are mlx5 hardware specific implementation for hardware
forwarding of such packets.

For debug purposes, introduce debugfs files which:
* Expose the number of active hairpins
* Dump the hairpin table
* Allow control over the number and size of the hairpin queues instead
  of the hard-coded values.

This allows us to get visibility of the feature in order to improve it
for next generation hardware.

Add debugfs files:
  fs/tc/hairpin_num_active
  fs/tc/hairpin_num_queues
  fs/tc/hairpin_queue_size
  fs/tc/hairpin_table_dump

Note that the new values will only take effect on the next queues
creation, it does not affect existing queues.
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Add a debugfs directory for flow steering related information.
The directory is currently empty, and will hold the 'tc' subdirectory in
a downstream patch.
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

In preparation for downstream work to expose hairpin queues parameters,
introduce a hairpin parameters struct as part of the tc structure.
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Add TLS debugfs to improve observability by exposing the size of the tls
TX pool.

To observe the size of the TX pool:
$ cat /sys/kernel/debug/mlx5/<pci>/nic/tls/tx/pool_size
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Co-developed-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Similar to the mlx5_core debugfs, lay the groundwork for mlx5e debugfs
files under /sys/kernel/debug/mlx5/<pci>/nic/..
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Currently, the user can modify device's receive buffer size, modify the
mapping between QoS priority groups to buffers and change the buffer
state to become lossy/lossless via pfc command.

However, the shared receive buffer pool alignments, as a result of
such commands, is performed only when the shared buffer is in FW ownership.
When a user changes the mapping of priority groups or buffer size,
the shared buffer is moved to SW ownership.

Therefore, for devices that support shared buffer, handle the shared buffer
alignments in accordance to user's desired configurations.

Meaning, the following will be performed:
1. For every change of buffer's headroom, recalculate the size of shared
   buffer to be equal to "total_buffer_size" - "new_headroom_size".
   The new shared buffer size will be split in ratio of 3:1 between
   lossy and lossless pools, respectively.

2. For each port buffer change, count the number of lossless buffers.
   If there is only one lossless buffer, then set its lossless pool
   usage threshold to be infinite. Otherwise, if there is more than
   one lossless buffer, set a usage threshold for each lossless buffer.

While at it, add more verbosity to debug prints when handling user
commands, to assist in future debug.
Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

To allow users to configure shared receive buffer parameters through
dcbnl callbacks, expose an API to query and modify SBPR and SBCM registers,
which will be used in the upcoming patch.
Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Add the shared receive buffer management and configuration registers:
1. SBPR - Shared Buffer Pools Register
2. SBCM - Shared Buffer Class Management Register
Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Fix a typo of "permision" which should be "permission".
Signed-off-by: Dai Shixin <dai.shixin@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Link: https://lore.kernel.org/r/202301091935262709751@zte.com.cnSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Michael Walle says:

====================
net: mdio: Start separating C22 and C45

This patch set starts the separation of C22 and C45 MDIO bus
transactions at the API level to the MDIO Bus drivers. C45 read and
write ops are added to the MDIO bus driver structure, and the MDIO
core will try to use these ops if requested to perform a C45
transfer. If not available a fallback to the older API is made, to
allow backwards compatibility until all drivers are converted.

A few drivers are then converted to this new API.

The core DSA patch was dropped for now as there is still an ongoing
discussion. It will be picked up in a later series again.

v2: https://lore.kernel.org/r/20221227-v6-2-rc1-c45-seperation-v2-0-ddb37710e5a7@walle.cc
v1: https://lore.kernel.org/r/20220508153049.427227-1-andrew@lunn.ch
====================

Link: https://lore.kernel.org/r/20221227-v6-2-rc1-c45-seperation-v3-0-ade1deb438da@walle.ccSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The global2 SMI MDIO bus driver can perform both C22 and C45
transfers. Create separate functions for each and register the C45
versions using the new API calls where appropriate. Update the SERDES
code to make use of these new accessors.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Some DSA devices pass through PHY access to the MDIO bus the switch is
on. Add C45 versions of the current C22 helpers for nested accesses to
MDIO busses, so that C22 and C45 can be separated in these DSA
drivers.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The fec MDIO bus driver can perform both C22 and C45 transfers.
Create separate functions for each and register the C45 versions using
the new API calls where appropriate.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Wei Fang <wei.fang@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The xgmac MDIO bus driver can perform both C22 and C45 transfers.
Create separate functions for each and register the C45 versions using
the new API calls where appropriate.

While at it, remove the misleading comment. According to Vladimir
Oltean:
 - miimcom is a register accessed by fsl_pq_mdio.c, not by xgmac_mdio.c
 - "device dev" doesn't really refer to anything (maybe "dev_addr").
 - I don't understand what is meant by the comment "All PHY
   configuration has to be done through the TSEC1 MIIM regs". Or rather
   said, I think I understand, but it is irrelevant to the driver for 2
   reasons:
    * TSEC devices use the fsl_pq_mdio.c driver, not this one
    * It doesn't matter to this driver whose TSEC registers are used for
      MDIO access. The driver just works with the registers it's given,
      which is a concern for the device tree.
 - barring the above, the rest just describes the MDIO bus API, which is
   superfluous
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The marvell MDIO driver supports two different hardware blocks. The
XSMI block is C45 only. Convert this block to the new API, and only
populate the c45 calls in the bus structure.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The bitbbanging bus driver can perform both C22 and C45 transfers.
Create separate functions for each and register the C45 versions using
the new driver API calls.

The SH Ethernet driver places wrappers around these functions. In
order to not break boards which might be using C45, add similar
wrappers for C45 operations.
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Now that mdiobus_c45_addr() is only used within the MDIO code during
fallback, move the function next to its only users. This function
should not be used any more in drivers, the c45 helpers should be used
in its place, so hiding it away will prevent any new users from being
added.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When performing a C22 operation, check that the bus driver actually
provides the methods, and return -EOPNOTSUPP if not. C45 only busses
do exist, and in future their C22 methods will be NULL.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Now that C45 uses its own read/write methods, the validation performed
when a bus is registers needs updating. All combinations of C22 and
C45 are supported, but both read and write methods must be provided,
read only busses are not supported etc.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Convert the PCS-XPCS driver to make use of the C45 MDIO bus API for
modify_change().
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Currently C22 and C45 transactions are mixed over a combined API calls
which make use of a special bit in the reg address to indicate if a
C45 transaction should be performed. This makes it impossible to know
if the bus driver actually supports C45. Additionally, many C22 only
drivers don't return -EOPNOTSUPP when asked to perform a C45
transaction, they mistaking perform a C22 transaction.

This is the first step to cleanly separate C22 from C45. To maintain
backwards compatibility until all drivers which are capable of
performing C45 are converted to this new API, the helper functions
will fall back to the older API if the new API is not
supported. Eventually this fallback will be removed.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Michael Walle says:

====================
net: phy: mxl-gpy: broken interrupt fixes

The GPY215 has a broken interrupt pin. This patch series tries to
workaround that and because in general that is not possible, disables the
interrupts by default and falls back to polling mode. There is an opt-in
via the devicetree.

====================

Link: https://lore.kernel.org/r/20230109123013.3094144-1-michael@walle.ccSigned-off-by: Paolo Abeni <pabeni@redhat.com>

The interrupts on the GPY215B and GPY215C are broken and the only viable
fix is to disable them altogether. There is still the possibilty to
opt-in via the device tree.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Until now, it is not possible for a PHY driver to disable interrupts
during runtime. If a driver offers the .config_intr() as well as the
.handle_interrupt() ops, it is eligible for interrupt handling.
Introduce a new flag for the dev_flags property of struct phy_device, which
can be set by PHY driver to skip interrupt setup and fall back to polling
mode.

At the moment, this is used for the MaxLinear PHY which has broken
interrupt handling and there is a need to disable interrupts in some
cases.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Add the device tree bindings for the MaxLinear GPY2xx PHYs, which
essentially adds just one flag: maxlinear,use-broken-interrupts.

One might argue, that if interrupts are broken, just don't use
the interrupt property in the first place. But it needs to be more
nuanced. First, this interrupt line is also used to wake up systems by
WoL, which has nothing to do with the (broken) PHY interrupt handling.

Second and more importantly, there are devicetrees which have this
property set. Thus, within the driver we have to switch off interrupt
handling by default as a workaround. But OTOH, a systems designer who
knows the hardware and knows there are no shared interrupts for example,
can use this new property as a hint to the driver that it can enable the
interrupt nonetheless.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

MaxLinear is a manufacturer of integrated circuits.
https://www.maxlinear.comSigned-off-by: Michael Walle <michael@walle.cc>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Hans J. Schultz says:

====================
mv88e6xxx: Add MAB offload support

This patch-set adds MAB [1] offload support in mv88e6xxx.

Patch #1: Correct default return value for mv88e6xxx_port_bridge_flags.

Patch #2: Shorten the locked section in
          mv88e6xxx_g1_atu_prob_irq_thread_fn().

Patch #3: The MAB implementation for mv88e6xxx.

[1] https://git.kernel.org/netdev/net-next/c/4bf24ad09bc0
====================

Link: https://lore.kernel.org/r/20230108094849.1789162-1-netdev@kapio-technology.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

This implementation for the Marvell mv88e6xxx chip series is based on
handling ATU miss violations occurring when packets ingress on a port
that is locked with learning on. This will trigger a
SWITCHDEV_FDB_ADD_TO_BRIDGE event, which will result in the bridge module
adding a locked FDB entry. This bridge FDB entry will not age out as
it has the extern_learn flag set.

Userspace daemons can listen to these events and either accept or deny
access for the host, by either replacing the locked FDB entry with a
simple entry or leave the locked entry.

If the host MAC address is already present on another port, a ATU
member violation will occur, but to no real effect, and the packet will
be dropped in hardware. Statistics on these violations can be shown with
the command and example output of interest:

ethtool -S ethX
NIC statistics:
...
     atu_member_violation: 5
     atu_miss_violation: 23
...

Where ethX is the interface of the MAB enabled port.

Furthermore, as added vlan interfaces where the vid is not added to the
VTU will cause ATU miss violations reporting the FID as
MV88E6XXX_FID_STANDALONE, we need to check and skip the miss violations
handling in this case.
Signed-off-by: Hans J. Schultz <netdev@kapio-technology.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

As only the hardware access functions up til and including
mv88e6xxx_g1_atu_mac_read() called under the interrupt handler
need to take the chip lock, we release the chip lock after this call.
The follow up code that handles the violations can run without the
chip lock held.
In further patches, the violation handler function will even be
incompatible with having the chip lock held. This due to an AB/BA
ordering inversion with rtnl_lock().
Signed-off-by: Hans J. Schultz <netdev@kapio-technology.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The default return value -EOPNOTSUPP of mv88e6xxx_port_bridge_flags()
came from the return value of the DSA method port_egress_floods() in
commit 4f85901f ("net: dsa: mv88e6xxx: add support for bridge flags"),
but the DSA API was changed in commit a8b659e7 ("net: dsa: act as
passthrough for bridge port flags"), resulting in the return value
-EOPNOTSUPP not being valid anymore, and sections for new flags will not
need to set the return value to zero on success, as with the new mab flag
added in a following patch.
Signed-off-by: Hans J. Schultz <netdev@kapio-technology.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Add the necessary changes to support 10 Mbps speed for BaseT and SFP
port modes. This is supported in MAC ver >= 30H.
Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>
Link: https://lore.kernel.org/r/20230109101819.747572-1-Raju.Rangoju@amd.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

This enables link partner advertised support to show link modes and
pause frame use.
Signed-off-by: Jamie Gloudon <jamie.gloudon@gmx.fr>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20230103230653.1102544-1-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Since commit ce098da1 ("skbuff: Introduce slab_build_skb()")
drivers trying to build skb around slab-backed buffers should
go via slab_build_skb() rather than passing frag_size = 0 to
the main build_skb().

Remove the copy'n'pasted comments about 0 meaning slab.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Bjørn Mork says:

====================
r8152: allow firmwares with NCM support

Some device and firmware combinations with NCM support will
end up using the cdc_ncm driver by default.  This is sub-
optimal for the same reasons we've previously accepted the
blacklist hack in cdc_ether.

The recent support for subclassing the generic USB device
driver allows us to create a very slim driver with the same
functionality.  This patch set uses that to implement a
device specific configuration default which is independent
of any USB interface drivers.  This means that it works
equally whether the device initially ends up in NCM or ECM
mode, without depending on any code in the respective class
drivers.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The r8152 driver does not need this anymore.

Dropping blacklist entries adds optional support for these
devices in ECM mode.

The 8153 devices are handled by the r8153_ecm driver when
in ECM mode, and must still be blacklisted here.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

Subclassing the generic USB device driver to override the
default configuration selection regardless of matching interface
drivers.

The r815x family devices expose a vendor specific function which
the r8152 interface driver wants to handle.  This is the preferred
device mode. Additionally one or more USB class functions are
usually supported for hosts lacking a vendor specific driver. The
choice is USB configuration based, with one alternate function per
configuration.

Example device with both NCM and ECM alternate cfgs:

T:  Bus=02 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  4 Spd=5000 MxCh= 0
D:  Ver= 3.20 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 9 #Cfgs=  3
P:  Vendor=0bda ProdID=8156 Rev=31.00
S:  Manufacturer=Realtek
S:  Product=USB 10/100/1G/2.5G LAN
S:  SerialNumber=001000001
C:* #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr=256mA
I:* If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=00 Driver=r8152
E:  Ad=81(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E:  Ad=83(I) Atr=03(Int.) MxPS=   2 Ivl=128ms
C:  #Ifs= 2 Cfg#= 2 Atr=a0 MxPwr=256mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=0d Prot=00 Driver=
E:  Ad=83(I) Atr=03(Int.) MxPS=  16 Ivl=128ms
I:  If#= 1 Alt= 0 #EPs= 0 Cls=0a(data ) Sub=00 Prot=01 Driver=
I:  If#= 1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=01 Driver=
E:  Ad=81(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
C:  #Ifs= 2 Cfg#= 3 Atr=a0 MxPwr=256mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=06 Prot=00 Driver=
E:  Ad=83(I) Atr=03(Int.) MxPS=  16 Ivl=128ms
I:  If#= 1 Alt= 0 #EPs= 0 Cls=0a(data ) Sub=00 Prot=00 Driver=
I:  If#= 1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=
E:  Ad=81(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms

A problem with this is that Linux will prefer class functions over
vendor specific functions. Using the above example, Linux defaults
to cfg #2, running the device in a sub-optimal NCM mode.

Previously we've attempted to work around the problem by
blacklisting the devices in the ECM class driver "cdc_ether", and
matching on the ECM class function in the vendor specific interface
driver. The latter has been used to switch back to the vendor
specific configuration when the driver is probed for a class
function.

This workaround has several issues;
- class driver blacklists is additional maintanence cruft in an
  unrelated driver
- class driver blacklists prevents users from optionally running
  the devices in class mode
- each device needs double match entries in the vendor driver
- the initial probing as a class function slows down device
  discovery

Now these issues have become even worse with the introduction of
firmware supporting both NCM and ECM, where NCM ends up as the
default mode in Linux. To use the same workaround, we now have
to blacklist the devices in to two different class drivers and
add yet another match entry to the vendor specific driver.

This patch implements an alternative workaround strategy -
independent of the interface drivers.  It avoids adding a
blacklist to the cdc_ncm driver and will let us remove the
existing blacklist from the cdc_ether driver.

As an additional bonus, removing the blacklists allow users to
select one of the other device modes if wanted.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

Mat Martineau says:

====================
mptcp: Protocol in-use tracking and code cleanup

Here's a collection of commits from the MPTCP tree:

Patches 1-4 and 6 contain miscellaneous code cleanup for more consistent
use of helper functions, existing local variables, and better naming.

Patches 5, 7, and 9 add sock_prot_inuse tracking for MPTCP and an
associated self test.

Patch 8 modifies the mptcp_connect self test tool to exit on SIGUSR1
when in "slow mode".
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add the function chk_msk_inuse() to diag.sh, which is used to check the
statistics of mptcp socket in use. As mptcp socket in listen state will
be closed randomly after 'accept', we need to get the count of listening
mptcp socket through 'ss' command.

All tests pass.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For now, mptcp_connect won't exit after receiving the 'SIGUSR1' signal
if '-r' is set. Fix this by skipping poll and sleep in copyfd_io_poll()
if 'quit' is set.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Do the statistics of mptcp socket in use with sock_prot_inuse_add().
Therefore, we can get the count of used mptcp socket from
/proc/net/protocols:

& cat /proc/net/protocols
protocol  size sockets  memory press maxhdr  slab module     cl co di ac io in de sh ss gs se re sp bi br ha uh gp em
MPTCPv6   2048      0       0   no       0   yes  kernel      y  n  y  y  y  y  y  y  y  y  y  y  n  n  n  y  y  y  n
MPTCP     1896      1       0   no       0   yes  kernel      y  n  y  y  y  y  y  y  y  y  y  y  n  n  n  y  y  y  n
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>