After commit 1a557afc ("i40e: Refactor receive routine"),
rx_stats.realloc_count is no longer being incremented, so remove it.

The debugfs string was left, but hardcoded to 0. This is intended to
prevent breaking any existing code / scripts that are parsing debugfs
for i40e.
Signed-off-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

After loading driver hw-tc-offload is enabled by default.
Change the behaviour of driver to disable hw-tc-offload by default as
this is the expected state. Additionally since this impacts ntuple
feature state change the way of checking NETIF_F_HW_TC flag.
Signed-off-by: Norbert Zulinski <norbertx.zulinski@intel.com>
Signed-off-by: Przemyslaw Patynowski <przemyslawx.patynowski@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: Dave Switzer <david.switzer@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Russell King says:

====================
net: dsa: mv88e6xxx: convert to phylink_generic_validate()

The overall objective of this series is to convert the mv88e6xxx DSA
driver to use phylink_generic_validate().

Patch 1 adds a new helper mv88e6352_g2_scratch_port_has_serdes() which
indicates whether an 88e6352 port has a serdes associated with it. This
is necessary as ports 4 and 5 will normally be in automedia mode, where
the CMODE field in the port status register will change e.g. between 15
(internal PHY) and 9 (1000base-X) depending on whether the serdes has
link.

The existing code caches the cmode field, and depending whether the
serdes has link at probe time, determines whether we allow things such
as the serdes statistics to be accessed. This means if the link isn't
up at probe time, the serdes is essentially unavailable.

Patch 1 addresses this by reading the pin configuration to find out
whether the serdes is attached to port 4 or port 5.

Patch 2 is a joint effort between myself and Marek Behún, adding the
supported interfaces and MAC capabilities to all mv88e6xxx supported
switch devices. This is slightly more restrictive than the original
code as we didn't used to care too much about the interface mode, but
with this we do - which is why we must know if there's a serdes
associated now.

Patch 3 switches mv88e6xxx to use the generic validation by removing
the initialisation of the phylink_validate pointer in the dsa_ops
struct.

Patch 4 updates the statistics code to use the new helper in patch 1,
so the serdes statistics are available even if the link was down at
driver probe time.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The decision whether to report serdes statistics currently depends on
the cached C_Mode value for the port, read at probe time or updated by
configuration. However, port 4 can be in "automedia" mode when it is
used as a serdes port, meaning it switches between the internal PHY and
the serdes, changing the read-only C_Mode value depending on which
first gains link. Consequently, the C_Mode value read at probe does not
accurately reflect whether the port has the serdes associated with it.

In "net: dsa: mv88e6xxx: add mv88e6352_g2_scratch_port_has_serdes()",
we added a way to read the hardware configuration to determine which
port has the serdes associated with it. Use this to determine which
port reports the serdes statistics.
Reviewed-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that the mv88e6xxx chip drivers are supplying the supported
interfaces and MAC capabilities, switch the driver to use the generic
phylink validation implementation by removing our own validation
implementations. This causes DSA to call phylink_generic_validate()
on our behalf.
Reviewed-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Populate the supported interfaces and MAC capabilities for the
Marvell MV88E6xxx DSA switches in preparation to using these for the
validation functionality.

Patch co-authored by Marek.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marek Behún <kabel@kernel.org> [ fixed 6341 and 6393x ]
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Read the hardware configuration to determine which port is attached
to the serdes.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tobias Waldekranz says:

====================
net: dsa: mv88e6xxx: Improve standalone port isolation

The ideal isolation between standalone ports satisfies two properties:
1. Packets from one standalone port must not be forwarded to any other
   port.
2. Packets from a standalone port must be sent to the CPU port.

mv88e6xxx solves (1) by isolating standalone ports using the PVT. Up
to this point though, (2) has not guaranteed; as the ATU is still
consulted, there is a chance that incoming packets never reach the CPU
if its DA has previously been used as the SA of an earlier packet (see
1/5 for more details). This is typically not a problem, except for one
very useful setup in which switch ports are looped in order to run the
bridge kselftests in tools/testing/selftests/net/forwarding. This
series attempts to solve (2).

Ideally, we could simply use the "ForceMap" bit of more modern chips
(Agate and newer) to classify all incoming packets as MGMT. This is
not available on older silicon that is still widely used (Opal Plus
chips like the 6097 for example).

Instead, this series takes a two pronged approach:

1/5: Always clear MapDA on standalone ports to make sure that no ATU
     entry can lead packets astray. This solves (2) for single-chip
     systems.

2/5: Trivial prep work for 4/5.
3/5: Trivial prep work for 4/5.

4/5: On multi-chip systems though, this is not enough. On the incoming
     chip, the packet will be forced out towards the CPU thanks to
     1/5, but on any intermediate chips the ATU is still consulted. We
     override this behavior by marking the reserved standalone VID (0)
     as a policy VID, the DSA ports' VID policy is set to TRAP. This
     will cause the packet to be reclassified as MGMT on the first
     intermediate chip, after which it's a straight shot towards the
     CPU.

Finally, we allow more tests to be run on mv88e6xxx:

5/5: The bridge_vlan{,un}aware suites sets an ageing_time of 10s on
     the bridge it creates, but mv88e6xxx has a minimum supported time
     of 15s. Allow this time to be overridden in forwarding.config.

With this series in place, mv88e6xxx passes the following kselftest
suites:

- bridge_port_isolation.sh
- bridge_sticky_fdb.sh
- bridge_vlan_aware.sh
- bridge_vlan_unaware.sh

v1 -> v2:
  - Wording/spelling (Vladimir)
  - Use standard iterator in dsa_switch_upstream_port (Vladimir)
  - Limit enabling of VTU port policy to downstream DSA ports (Vladimir)
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Allow the ageing timeout that is set on bridges to be customized from
forwarding.config. This allows the tests to be run on hardware which
does not support a 10s timeout (e.g. mv88e6xxx).
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Given that standalone ports are now configured to bypass the ATU and
forward all frames towards the upstream port, extend the ATU bypass to
multichip systems.

Load VID 0 (standalone) into the VTU with the policy bit set. Since
VID 4095 (bridged) is already loaded, we now know that all VIDs in use
are always available in all VTUs. Therefore, we can safely enable
802.1Q on DSA ports.

Setting the DSA ports' VTU policy to TRAP means that all incoming
frames on VID 0 will be classified as MGMT - as a result, the ATU is
bypassed on all subsequent switches.

With this isolation in place, we are able to support configurations
that are simultaneously very quirky and very useful. Quirky because it
involves looping cables between local switchports like in this
example:

   CPU
    |     .------.
.---0---. | .----0----.
|  sw0  | | |   sw1   |
'-1-2-3-' | '-1-2-3-4-'
  $ @ '---'   $ @ % %

We have three physically looped pairs ($, @, and %).

This is very useful because it allows us to run the kernel's
kselftests for the bridge on mv88e6xxx hardware.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This chip has support for the same per-port policy actions found in
later versions of LinkStreet devices.

Fixes: f3a2cd32 ("net: dsa: mv88e6xxx: introduce .port_set_policy")
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A VTU entry with policy enabled is used in combination with a port's
VTU policy setting to override normal switching behavior for frames
assigned to the entry's VID.

A typical example is to Treat all frames in a particular VLAN as
control traffic, and trap them to the CPU. In which case the relevant
user port's VTU policy would be set to TRAP.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Clear MapDA on standalone ports to bypass any ATU lookup that might
point the packet in the wrong direction. This means that all packets
are flooded using the PVT config. So make sure that standalone ports
are only allowed to communicate with the local upstream port.

Here is a scenario in which this is needed:

   CPU
    |     .----.
.---0---. | .--0--.
|  sw0  | | | sw1 |
'-1-2-3-' | '-1-2-'
      '---'

- sw0p1 and sw1p1 are bridged
- sw0p2 and sw1p2 are in standalone mode
- Learning must be enabled on sw0p3 in order for hardware forwarding
  to work properly between bridged ports

1. A packet with SA :aa comes in on sw1p2
   1a. Egresses sw1p0
   1b. Ingresses sw0p3, ATU adds an entry for :aa towards port 3
   1c. Egresses sw0p0

2. A packet with DA :aa comes in on sw0p2
   2a. If an ATU lookup is done at this point, the packet will be
       incorrectly forwarded towards sw0p3. With this change in place,
       the ATU is bypassed and the packet is forwarded in accordance
       with the PVT, which only contains the CPU port.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Miroslav Lichvar says:

====================
Virtual PTP clock improvements and fix

v2:
- dropped patch changing initial time of virtual clocks

The first patch fixes an oops when unloading a driver with PTP clock and
enabled virtual clocks.

The other patches add missing features to make synchronization with
virtual clocks work as well as with the physical clock.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

If the physical clock supports cross timestamping (it has the
getcrosststamp() function), provide a wrapper in the virtual clock to
enable cross timestamping.

This adds support for the PTP_SYS_OFFSET_PRECISE ioctl.
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Cc: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If the physical clock has the gettimex64() function, provide a
gettimex64() wrapper in the virtual clock to enable more accurate
and stable synchronization.

This adds support for the PTP_SYS_OFFSET_EXTENDED ioctl.
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Cc: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Increase the maximum frequency offset of virtual clocks to 50% to enable
faster slewing corrections.

This value cannot be represented as scaled ppm when long has 32 bits,
but that is already the case for other drivers, even those that provide
the adjfine() function, i.e. 32-bit applications are expected to check
for the limit.
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Cc: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When unregistering a physical clock which has some virtual clocks,
unregister the virtual clocks with it.

This fixes the following oops, which can be triggered by unloading
a driver providing a PTP clock when it has enabled virtual clocks:

BUG: unable to handle page fault for address: ffffffffc04fc4d8
Oops: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:ptp_vclock_read+0x31/0xb0
Call Trace:
 timecounter_read+0xf/0x50
 ptp_vclock_refresh+0x2c/0x50
 ? ptp_clock_release+0x40/0x40
 ptp_aux_kworker+0x17/0x30
 kthread_worker_fn+0x9b/0x240
 ? kthread_should_park+0x30/0x30
 kthread+0xe2/0x110
 ? kthread_complete_and_exit+0x20/0x20
 ret_from_fork+0x22/0x30

Fixes: 73f37068 ("ptp: support ptp physical/virtual clocks conversion")
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Cc: Yangbo Lu <yangbo.lu@nxp.com>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This change is meant to permit a driver to perform "fragmenting" of the
page from within the driver instead of the current model which requires
pre-partitioning the page. The main motivation behind this is to support
use cases where the page will be split up by the driver after DMA instead
of before.

With this change it becomes possible to start using page pool to replace
some of the existing use cases where multiple references were being used
for a single page, but the number needed was unknown as the size could be
dynamic.

For example, with this code it would be possible to do something like
the following to handle allocation:
  page = page_pool_alloc_pages();
  if (!page)
    return NULL;
  page_pool_fragment_page(page, DRIVER_PAGECNT_BIAS_MAX);
  rx_buf->page = page;
  rx_buf->pagecnt_bias = DRIVER_PAGECNT_BIAS_MAX;

Then we would process a received buffer by handling it with:
  rx_buf->pagecnt_bias--;

Once the page has been fully consumed we could then flush the remaining
instances with:
  if (page_pool_defrag_page(page, rx_buf->pagecnt_bias))
    continue;
  page_pool_put_defragged_page(pool, page -1, !!budget);

The general idea is that we want to have the ability to allocate a page
with excess fragment count and then trim off the unneeded fragments.
Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Russell King says:

====================
Trivial DSA conversions to phylink_generic_validate()

This series converts five DSA drivers to use phylink_generic_validate().
No feedback or testing reports were received from the CFT posting.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Populate the supported interfaces and MAC capabilities for the xrs700x
family of DSA switches and remove the old validate implementation to
allow DSA to use phylink_generic_validate() for this switch driver.

According to commit ee00b24f ("net: dsa: add Arrow SpeedChips
XRS700x driver") the switch supports one RMII port and up to three
RGMII ports. This commit assumes that port 0 is the RMII port and the
remainder are RGMII.

This commit also results in the Autoneg bit being set in the ethtool
link modes, which wasn't in the original; if this switch supports
RGMII to a 10/100/1G PHY, then surely we want to allow Autoneg on the
PHY.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Populate the supported interfaces and MAC capabilities for the QCA8K
DSA switch and remove the old validate implementation to allow DSA to
use phylink_generic_validate() for this switch driver.

In making this change, we bring consistency to the ethtool linkmodes
that phylink's validate step produces, thereby following the expected
behaviour as the phylink documentation has explained. Specifically, the
ethtool 1000baseX_Full capability is now permitted for all interface
modes, as it is a property of the PHY driver whether 1000baseX fiber
connections can be supported.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Populate the supported interfaces and MAC capabilities for the
Microchip KSZ8795 DSA switch and remove the old validate implementation
to allow DSA to use phylink_generic_validate() for this switch driver.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Populate the supported interfaces and MAC capabilities for the bcm_sf2
DSA switch and remove the old validate implementation to allow DSA to
use phylink_generic_validate() for this switch driver.

The exclusion of Gigabit linkmodes for MII and Reverse MII links is
handled within phylink_generic_validate() in phylink, so there is no
need to make them conditional on the interface mode in the driver.

Thanks to Florian Fainelli for suggesting how to populate the supported
interfaces.

Link: https://lore.kernel.org/r/3b3fed98-0c82-99e9-dc72-09fe01c2bcf3@gmail.comSigned-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Populate the supported interfaces and MAC capabilities for the AR9331
DSA switch and remove the old validate implementation to allow DSA to
use phylink_generic_validate() for this switch driver.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Mat Martineau says:

====================
mptcp: Miscellaneous changes for 5.18

Patch 1 has some minor cleanup in mptcp_write_options().

Patch 2 moves a rarely-needed branch to optimize mptcp_write_options().

Patch 3 adds a comment explaining which combinations of MPTCP option
headers are expected.

Patch 4 adds a pr_debug() for the MPTCP_RST option.

Patches 5-7 allow setting MPTCP_PM_ADDR_FLAG_FULLMESH with the "set
flags" netlink command. This allows changing the behavior of existing
path manager endpoints. The flag was previously only set at endpoint
creation time. Associated selftests also updated.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch added the fullmesh setting and clearing selftests in
mptcp_join.sh.

Now we can set both backup and fullmesh flags, so avoid using the
words 'backup' and 'bkup'.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch added the fullmesh flag setting and clearing support in
pm_nl_ctl:

 # pm_nl_ctl set ip flags fullmesh
 # pm_nl_ctl set ip flags nofullmesh
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch added the fullmesh flag setting support in pm_netlink.

If the fullmesh flag of the address is changed, remove all the related
subflows, update the fullmesh flag and create subflows again.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch printed out the reset infos, reset_transient and reset_reason,
of MP_RST in mptcp_parse_option() to show that MP_RST is received.
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RFC8684 doesn't seem to clearly specify which MPTCP options can be used
together.

Some options are mutually exclusive -- e.g. MP_CAPABLE and MP_JOIN --,
some can be used together -- e.g. DSS + MP_PRIO --, some can but we
prefer not to -- e.g. DSS + ADD_ADDR -- and some have to be used
together at some points -- e.g. MP_FAIL and DSS.

We need to clarify this as a base before allowing other modifications.

For example, does it make sense to send a RM_ADDR with an MPC or MPJ?
This remains open for possible future discussions.
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

MP_FAIL should be use in very rare cases, either when the TCP RST flag
is set -- with or without an MP_RST -- or with a DSS, see
mptcp_established_options().

Here, we do the same in mptcp_write_options().
Co-developed-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Move the declarations of ssk and subflow in MP_FAIL and MP_PRIO to the
beginning of the function mptcp_write_options().
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alex Elder says:

====================
net: ipa: support variable RX buffer size

Specify the size of receive buffers used for RX endpoints in the
configuration data, rather than using 8192 bytes for all of them.
Increase the size of the AP receive buffer for the modem to 32KB.
====================

Link: https://lore.kernel.org/r/20220201153737.601149-1-elder@linaro.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Increase the receive buffer size used for data received from the
modem to 32KB, to improve download performance by allowing much
greater aggregation.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Allow RX endpoints to have differing receive buffer sizes.  Define
the receive buffer size in the configuration data, and use that
rather than IPA_RX_BUFFER_SIZE when configuring the endpoint.

Add verification in ipa_endpoint_data_valid_one() that the receive
buffer specified for AP RX endpoints is both big enough to handle at
least one full packet, and not so big in an aggregating endpoint
that its size can't be represented when programming the hardware.
Move aggr_byte_limit_max() up in "ipa_endpoint.c" so it can be used
earlier in the file without a forward-reference.

Initially we'll just keep the 8KB receive buffer size already in use
for all AP RX endpoints..
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Replace acpi_bus_get_device() that is going to be dropped with
acpi_fetch_acpi_dev().

No intentional functional impact.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/11918902.O9o76ZdvQC@kreacher
Link: https://lore.kernel.org/r/11920660.O9o76ZdvQC@kreacherSigned-off-by: Jakub Kicinski <kuba@kernel.org>

When setting RTO through BPF program, some SYN ACK packets were unaffected
and continued to use TCP_TIMEOUT_INIT constant. This patch adds timeout
option to struct request_sock. Option is initialized with TCP_TIMEOUT_INIT
and is reassigned through BPF using tcp_timeout_init call. SYN ACK
retransmits now use newly added timeout option.
Signed-off-by: Akhmat Karakotov <hmukos@yandex-team.ru>
Acked-by: Martin KaFai Lau <kafai@fb.com>

v2:
	- Add timeout option to struct request_sock. Do not call
	  tcp_timeout_init on every syn ack retransmit.

v3:
	- Use unsigned long for min. Bound tcp_timeout_init to TCP_RTO_MAX.

v4:
	- Refactor duplicate code by adding reqsk_timeout function.
Signed-off-by: David S. Miller <davem@davemloft.net>

Ansuel Smith says:

====================
Add support for qca8k mdio rw in Ethernet packet

The main reason for this is that we notice some routing problem in the
switch and it seems assisted learning is needed. Considering mdio is
quite slow due to the indirect write using this Ethernet alternative way
seems to be quicker.

The qca8k switch supports a special way to pass mdio read/write request
using specially crafted Ethernet packet.
This works by putting some defined data in the Ethernet header where the
mac source and dst should be placed. The Ethernet type header is set to qca
header and is set to a mdio read/write type.
This is used to communicate to the switch that this is a special packet
and should be parsed differently.

Currently we use Ethernet packet for
- MIB counter
- mdio read/write configuration
- phy read/write for each port

Current implementation of this use completion API to wait for the packet
to be processed by the tagger and has a timeout that fallback to the
legacy mdio way and mutex to enforce one transaction at time.

We now have connect()/disconnect() ops for the tagger. They are used to
allocate priv data in the dsa priv. The header still has to be put in
global include to make it usable by a dsa driver.
They are called when the tag is connect to the dst and the data is freed
using discconect on tagger change.

(if someone wonder why the bind function is put at in the general setup
function it's because tag is set in the cpu port where the notifier is
still not available and we require the notifier to sen the
tag_proto_connect() event.

We now have a tag_proto_connect() for the dsa driver used to put
additional data in the tagger priv (that is actually the dsa priv).
This is called using a switch event DSA_NOTIFIER_TAG_PROTO_CONNECT.
Current use for this is adding handler for the Ethernet packet to keep
the tagger code as dumb as possible.

The tagger priv implement only the handler for the special packet. All the
other stuff is placed in the qca8k_priv and the tagger has to access
it under lock.

We use the new API from Vladimir to track if the master port is
operational or not. We had to track many thing to reach a usable state.
Checking if the port is UP is not enough and tracking a NETDEV_CHANGE is
also not enough since it use also for other task. The correct way was
both track for interface UP and if a qdisc was assigned to the
interface. That tells us the port (and the tagger indirectly) is ready
to accept and process packet.

I tested this with multicpu port and with port6 set as the unique port and
it's sad.
It seems they implemented this feature in a bad way and this is only
supported with cpu port0. When cpu port6 is the unique port, the switch
doesn't send ack packet. With multicpu port, packet ack are not duplicated
and only cpu port0 sends them. This is the same for the MIB counter.
For this reason this feature is enabled only when cpu port0 is enabled and
operational.

v8:
- Reworked to rolling counter for the seq_num
- Reworked the hi/lo cache patch
- Fix multiple missing skb free and mutex lock errors
- Fix some spelling mistake
- Add macro build check for mgmt packet size
- Change some struct naming to make them more descriptive
v7:
- Rebase on net-next changes
- Add bulk patches to speedup this even more
v6:
- Fix some error in ethtool handler caused by rebase/cleanup
v5:
- Adapt to new API fixes
- Fix a wrong logic for noop
- Add additional lock for master_state change
- Limit mdio Ethernet to cpu port0 (switch limitation)
- Add priority to these special packet
- Move mdio cache to qca8k_priv
v4:
- Remove duplicate patch sent by mistake.
v3:
- Include MIB with Ethernet packet.
- Include phy read/write with Ethernet packet.
- Reorganize code with new API.
- Introuce master tracking by Vladimir
v2:
- Address all suggestion from Vladimir.
  Try to generilize this with connect/disconnect function from the
  tagger and tag_proto_connect for the driver.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Introduce qca8k_bulk_read/write() function to use mgmt Ethernet way to
read/write packet in bulk. Make use of this new function in the fdb
function and while at it reduce the reg for fdb_read from 4 to 3 as the
max bit for the ARL(fdb) table is 83 bits.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>