The more sockets we have in the hash table, the longer we spend looking
up the socket.  While running a number of small workloads on the same
host, they penalise each other and cause performance degradation.

The root cause might be a single workload that consumes much more
resources than the others.  It often happens on a cloud service where
different workloads share the same computing resource.

On EC2 c5.24xlarge instance (196 GiB memory and 524288 (1Mi / 2) ehash
entries), after running iperf3 in different netns, creating 24Mi sockets
without data transfer in the root netns causes about 10% performance
regression for the iperf3's connection.

 thash_entries		sockets		length		Gbps
	524288		      1		     1		50.7
			   24Mi		    48		45.1

It is basically related to the length of the list of each hash bucket.
For testing purposes to see how performance drops along the length,
I set 131072 (1Mi / 8) to thash_entries, and here's the result.

 thash_entries		sockets		length		Gbps
        131072		      1		     1		50.7
			    1Mi		     8		49.9
			    2Mi		    16		48.9
			    4Mi		    32		47.3
			    8Mi		    64		44.6
			   16Mi		   128		40.6
			   24Mi		   192		36.3
			   32Mi		   256		32.5
			   40Mi		   320		27.0
			   48Mi		   384		25.0

To resolve the socket lookup degradation, we introduce an optional
per-netns hash table for TCP, but it's just ehash, and we still share
the global bhash, bhash2 and lhash2.

With a smaller ehash, we can look up non-listener sockets faster and
isolate such noisy neighbours.  In addition, we can reduce lock contention.

We can control the ehash size by a new sysctl knob.  However, depending
on workloads, it will require very sensitive tuning, so we disable the
feature by default (net.ipv4.tcp_child_ehash_entries == 0).  Moreover,
we can fall back to using the global ehash in case we fail to allocate
enough memory for a new ehash.  The maximum size is 16Mi, which is large
enough that even if we have 48Mi sockets, the average list length is 3,
and regression would be less than 1%.

We can check the current ehash size by another read-only sysctl knob,
net.ipv4.tcp_ehash_entries.  A negative value means the netns shares
the global ehash (per-netns ehash is disabled or failed to allocate
memory).

  # dmesg | cut -d ' ' -f 5- | grep "established hash"
  TCP established hash table entries: 524288 (order: 10, 4194304 bytes, vmalloc hugepage)

  # sysctl net.ipv4.tcp_ehash_entries
  net.ipv4.tcp_ehash_entries = 524288  # can be changed by thash_entries

  # sysctl net.ipv4.tcp_child_ehash_entries
  net.ipv4.tcp_child_ehash_entries = 0  # disabled by default

  # ip netns add test1
  # ip netns exec test1 sysctl net.ipv4.tcp_ehash_entries
  net.ipv4.tcp_ehash_entries = -524288  # share the global ehash

  # sysctl -w net.ipv4.tcp_child_ehash_entries=100
  net.ipv4.tcp_child_ehash_entries = 100

  # ip netns add test2
  # ip netns exec test2 sysctl net.ipv4.tcp_ehash_entries
  net.ipv4.tcp_ehash_entries = 128  # own a per-netns ehash with 2^n buckets

When more than two processes in the same netns create per-netns ehash
concurrently with different sizes, we need to guarantee the size in
one of the following ways:

  1) Share the global ehash and create per-netns ehash

  First, unshare() with tcp_child_ehash_entries==0.  It creates dedicated
  netns sysctl knobs where we can safely change tcp_child_ehash_entries
  and clone()/unshare() to create a per-netns ehash.

  2) Control write on sysctl by BPF

  We can use BPF_PROG_TYPE_CGROUP_SYSCTL to allow/deny read/write on
  sysctl knobs.

Note that the global ehash allocated at the boot time is spread over
available NUMA nodes, but inet_pernet_hashinfo_alloc() will allocate
pages for each per-netns ehash depending on the current process's NUMA
policy.  By default, the allocation is done in the local node only, so
the per-netns hash table could fully reside on a random node.  Thus,
depending on the NUMA policy the netns is created with and the CPU the
current thread is running on, we could see some performance differences
for highly optimised networking applications.

Note also that the default values of two sysctl knobs depend on the ehash
size and should be tuned carefully:

  tcp_max_tw_buckets  : tcp_child_ehash_entries / 2
  tcp_max_syn_backlog : max(128, tcp_child_ehash_entries / 128)

As a bonus, we can dismantle netns faster.  Currently, while destroying
netns, we call inet_twsk_purge(), which walks through the global ehash.
It can be potentially big because it can have many sockets other than
TIME_WAIT in all netns.  Splitting ehash changes that situation, where
it's only necessary for inet_twsk_purge() to clean up TIME_WAIT sockets
in each netns.

With regard to this, we do not free the per-netns ehash in inet_twsk_kill()
to avoid UAF while iterating the per-netns ehash in inet_twsk_purge().
Instead, we do it in tcp_sk_exit_batch() after calling tcp_twsk_purge() to
keep it protocol-family-independent.

In the future, we could optimise ehash lookup/iteration further by removing
netns comparison for the per-netns ehash.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

While destroying netns, we call inet_twsk_purge() in tcp_sk_exit_batch()
and tcpv6_net_exit_batch() for AF_INET and AF_INET6.  These commands
trigger the kernel to walk through the potentially big ehash twice even
though the netns has no TIME_WAIT sockets.

  # ip netns add test
  # ip netns del test

  or

  # unshare -n /bin/true >/dev/null

When tw_refcount is 1, we need not call inet_twsk_purge() at least
for the net.  We can save such unneeded iterations if all netns in
net_exit_list have no TIME_WAIT sockets.  This change eliminates
the tax by the additional unshare() described in the next patch to
guarantee the per-netns ehash size.

Tested:

  # mount -t debugfs none /sys/kernel/debug/
  # echo cleanup_net > /sys/kernel/debug/tracing/set_ftrace_filter
  # echo inet_twsk_purge >> /sys/kernel/debug/tracing/set_ftrace_filter
  # echo function > /sys/kernel/debug/tracing/current_tracer
  # cat ./add_del_unshare.sh
  for i in `seq 1 40`
  do
      (for j in `seq 1 100` ; do  unshare -n /bin/true >/dev/null ; done) &
  done
  wait;
  # ./add_del_unshare.sh

Before the patch:

  # cat /sys/kernel/debug/tracing/trace_pipe
    kworker/u128:0-8       [031] ...1.   174.162765: cleanup_net <-process_one_work
    kworker/u128:0-8       [031] ...1.   174.240796: inet_twsk_purge <-cleanup_net
    kworker/u128:0-8       [032] ...1.   174.244759: inet_twsk_purge <-tcp_sk_exit_batch
    kworker/u128:0-8       [034] ...1.   174.290861: cleanup_net <-process_one_work
    kworker/u128:0-8       [039] ...1.   175.245027: inet_twsk_purge <-cleanup_net
    kworker/u128:0-8       [046] ...1.   175.290541: inet_twsk_purge <-tcp_sk_exit_batch
    kworker/u128:0-8       [037] ...1.   175.321046: cleanup_net <-process_one_work
    kworker/u128:0-8       [024] ...1.   175.941633: inet_twsk_purge <-cleanup_net
    kworker/u128:0-8       [025] ...1.   176.242539: inet_twsk_purge <-tcp_sk_exit_batch

After:

  # cat /sys/kernel/debug/tracing/trace_pipe
    kworker/u128:0-8       [038] ...1.   428.116174: cleanup_net <-process_one_work
    kworker/u128:0-8       [038] ...1.   428.262532: cleanup_net <-process_one_work
    kworker/u128:0-8       [030] ...1.   429.292645: cleanup_net <-process_one_work
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We will soon introduce an optional per-netns ehash.

This means we cannot use tcp_hashinfo directly in most places.

Instead, access it via net->ipv4.tcp_death_row.hashinfo.

The access will be valid only while initialising tcp_hashinfo
itself and creating/destroying each netns.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We will soon introduce an optional per-netns ehash.

This means we cannot use the global sk->sk_prot->h.hashinfo
to fetch a TCP hashinfo.

Instead, set NULL to sk->sk_prot->h.hashinfo for TCP and get
a proper hashinfo from net->ipv4.tcp_death_row.hashinfo.

Note that we need not use sk->sk_prot->h.hashinfo if DCCP is
disabled.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We will soon introduce an optional per-netns ehash and access hash
tables via net->ipv4.tcp_death_row->hashinfo instead of &tcp_hashinfo
in most places.

It could harm the fast path because dereferences of two fields in net
and tcp_death_row might incur two extra cache line misses.  To save one
dereference, let's place tcp_death_row back in netns_ipv4 and fetch
hashinfo via net->ipv4.tcp_death_row"."hashinfo.

Note tcp_death_row was initially placed in netns_ipv4, and commit
fbb82952 ("tcp: allocate tcp_death_row outside of struct netns_ipv4")
changed it to a pointer so that we can fire TIME_WAIT timers after freeing
net.  However, we don't do so after commit 04c494e6 ("Revert "tcp/dccp:
get rid of inet_twsk_purge()""), so we need not define tcp_death_row as a
pointer.

Also, we move refcount_dec_and_test(&tw_refcount) from tcp_sk_exit() to
tcp_sk_exit_batch() as a debug check.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This patch adds no functional change and cleans up some functions
that the following patches touch around so that we make them tidy
and easy to review/revert.  The changes are

  - Keep reverse christmas tree order
  - Remove unnecessary init of port in inet_csk_find_open_port()
  - Use req_to_sk() once in reqsk_queue_unlink()
  - Use sock_net(sk) once in tcp_time_wait() and tcp_v[46]_connect()
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Remove a left-over from commit 2874c5fd ("treewide: Replace GPLv2
boilerplate/reference with SPDX - rule 152")

There is no need for an empty "License:".
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/0e5ff727626b748238f4b78932f81572143d8f0b.1662896317.git.christophe.jaillet@wanadoo.frSigned-off-by: Jakub Kicinski <kuba@kernel.org>

This is a regression test for commit 592335a4 ("bonding: accept
unsolicited NA message") and commit b7f14132 ("bonding: use unspecified
address if no available link local address"). When the bond interface
up and no available link local address, unspecified address(::) is used to
send the NS message. The unsolicited NA message should also be accepted
for validation.
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Jonathan Toppins <jtoppins@redhat.com>
Link: https://lore.kernel.org/r/20220920033047.173244-1-liuhangbin@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

dev_err() can be replace with dev_err_probe() which will check if error
code is -EPROBE_DEFER.
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220915065043.665138-3-yangyingliang@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

dev_err() can be replace with dev_err_probe() which will check if error
code is -EPROBE_DEFER.
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220915065043.665138-2-yangyingliang@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

dev_err() can be replace with dev_err_probe() which will check if error
code is -EPROBE_DEFER.
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220915065043.665138-1-yangyingliang@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

EMAC IP found on RZ/G2L Gb ethernet supports MII interface.
This patch adds support for selecting MII interface mode.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/20220914192604.265859-1-biju.das.jz@bp.renesas.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Unlike with bridges, one can't add an interface to a bond and set it up
at the same time:

| # ip link set dummy0 down
| # ip link set dummy0 master bond0 up
| Error: Device can not be enslaved while up.

Of all drivers with ndo_add_slave callback, bond and team decline if
IFF_UP flag is set, vrf cycles the interface (i.e., sets it down and
immediately up again) and the others just don't care.

Support the common notion of setting the interface up after enslaving it
by sorting the operations accordingly.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220914150623.24152-1-phil@nwl.ccSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Radhey Shyam Pandey says:

====================
macb: add zynqmp SGMII dynamic configuration support

This patchset add firmware and driver support to do SD/GEM dynamic
configuration. In traditional flow GEM secure space configuration
is done by FSBL. However in specific usescases like dynamic designs
where GEM is not enabled in base vivado design, FSBL skips GEM
initialization and we need a mechanism to configure GEM secure space
in linux space at runtime.
====================

Link: https://lore.kernel.org/r/1663158796-14869-1-git-send-email-radhey.shyam.pandey@amd.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Add support for the dynamic configuration which takes care of
configuring the GEM secure space configuration registers
using EEMI APIs.
High level sequence is to:
- Check for the PM dynamic configuration support, if no error proceed with
  GEM dynamic configurations(next steps) otherwise skip the dynamic
  configuration.
- Configure GEM Fixed configurations.
- Configure GEM_CLK_CTRL (gemX_sgmii_mode).
- Trigger GEM reset.
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Conor Dooley <conor.dooley@microchip.com> (for MPFS)
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add new APIs in firmware to configure SD/GEM registers. Internally
it calls PM IOCTL for below SD/GEM register configuration:
- SD/EMMC select
- SD slot type
- SD base clock
- SD 8 bit support
- SD fixed config
- GEM SGMII Mode
- GEM fixed config
Signed-off-by: Ronak Jain <ronak.jain@xilinx.com>
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The symbol is not used outside of the file, so mark it static.

Fixes the following warning:

./drivers/net/xen-netfront.c:676:16: warning: symbol 'bounce_skb' was not declared. Should it be static?
Signed-off-by: ruanjinjie <ruanjinjie@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20220914064339.49841-1-ruanjinjie@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Add support for interrupts for LAN8804 PHY.

Tested-by: Michael Walle <michael@walle.cc> # on kontron-kswitch-d10
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Link: https://lore.kernel.org/r/20220913142926.816746-1-horatiu.vultur@microchip.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Russell King says:

====================
sfp: add support for HALNy GPON module

This series adds support for the HALNy GPON SFP module. In order to do
this sensibly, we need a more flexible quirk system, since we need to
change the behaviour of the SFP cage driver to ignore the LOS and
TX_FAULT signals after module detection.

Since we move the SFP quirks into the SFP cage driver, we can use it
for the MA5671A and 3FE46541AA modules as well.
====================

Link: https://lore.kernel.org/r/YyDUnvM1b0dZPmmd@shell.armlinux.org.ukSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Add a quirk for the HALNy HL-GSFP module, which appears to have an
inverted RX_LOS signal, and maybe uses TX_FAULT as a serial port
transmit pin. Rather than use these hardware signals, switch to
using software polling for these status signals.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Move this module over to the new fixup mechanism.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add a new fixup mechanism to the SFP quirks, and use it for this
module.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We need to handle more quirks than just those which affect the link
modes of the module. Move the quirk lookup into sfp.c, and pass the
quirk to sfp-bus.c
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Re-implement the decision making for soft state polling. Instead of
generating the soft state mask in sfp_soft_start_poll() by looking at
which GPIOs are available, record their availability in
sfp_sm_mod_probe() in sfp->state_hw_mask.

This will then allow us to clear bits in sfp->state_hw_mask in module
specific quirks when the hardware signals should not be used, thereby
allowing us to switch to using the software state polling.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Replace the free-form description of device tree bindings for VSC9959
and VSC9953 with a YAML formatted dt-schema description. This contains
more or less the same information, but reworded to be a bit more
succint.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Maxim Kochetkov <fido_max@inbox.ru>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220913125806.524314-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Alex Elder says:

====================
net: ipa: a mix of cleanups

This series contains a set of cleanups done in preparation for a
more substantitive upcoming series that reworks how IPA registers
and their fields are defined.

The first eliminates about half of the possible GSI register
constant symbols by removing offset definitions that are not
currently required.

The next two mainly rearrange code for some common enumerated types.

The next one fixes two spots that reuse local variable names in
inner scopes when defining offsets.

The next adds some additional restrictions on the value held in a
register.

And the last one just fixes two field mask symbol names so they
adhere to the common naming convention.
====================

Link: https://lore.kernel.org/r/20220910011131.1431934-1-elder@linaro.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

All field mask symbols are defined with a "_FMASK" suffix, but
EOT_COAL_GRANULARITY and DRBIP_ACL_ENABLE are defined without one.
Fix that.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Starting with IPA v4.5, replication is done differently from before,
and as a result the "replication" portion of the how the sequencer
is specified must be zero.

Add a check for the configuration data failing that requirement, and
only update the sesquencer type value when it's supported.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In ipa_endpoint_init_hdr(), as well as ipa_endpoint_init_hdr_ext(),
a top-level automatic variable named "offset" is used to represent
the offset of a register.

However, deeper within each of those functions is *another*
definition of a local variable with the same name, representing
something else.  Scoping rules ensure the result is what was
intended, but this variable name reuse is bad practice and makes
the code confusing.

Fix this by naming the inner variable "off".  Use "off" instead of
"checksum_offset" in ipa_endpoint_init_cfg() for consistency.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Move the definition of ipa_version_valid(), making it a static
inline function defined together with the enumerated type in
"ipa_version.h".  Define a new count value in the type.

Rename the function to be ipa_version_supported(), and have it
return true only if the IPA version supplied is explicitly supported
by the driver.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Move the definition of the gsi_ee_id enumerated type out of "gsi.h"
and into "ipa_version.h".  That latter header file isolates the
definition of the ipa_version enumerated type, allowing it to be
included in both IPA and GSI code.  We have the same requirement for
gsi_ee_id, and moving it here makes it easier to get only that
definition without everything else defined in "gsi.h".
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Each GSI execution environment (EE) is able to access many of the
GSI registers associated with the other EEs.  A block of GSI
registers is contained within a region of memory, and an EE's
register offset can be determined by adding the register's base
offset to the product of the EE ID and a fixed constant.

Despite this possibility, the AP IPA code *never* accesses any GSI
registers other than its own.  So there's no need to define the
macros that compute register offsets for other EEs.

Redefine the AP access macros to compute the offset the way the more
general "any EE" macro would, and get rid of the unneeded macros.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Alexandru Tachici says:

====================
net: ethernet: adi: Add ADIN1110 support

The ADIN1110 is a low power single port 10BASE-T1L MAC-PHY
designed for industrial Ethernet applications. It integrates
an Ethernet PHY core with a MAC and all the associated analog
circuitry, input and output clock buffering.

ADIN1110 MAC-PHY encapsulates the ADIN1100 PHY. The PHY registers
can be accessed through the MDIO MAC registers.
We are registering an MDIO bus with custom read/write in order
to let the PHY to be discovered by the PAL. This will let
the ADIN1100 Linux driver to probe and take control of
the PHY.

The ADIN2111 is a low power, low complexity, two-Ethernet ports
switch with integrated 10BASE-T1L PHYs and one serial peripheral
interface (SPI) port.

The device is designed for industrial Ethernet applications using
low power constrained nodes and is compliant with the IEEE 802.3cg-2019
Ethernet standard for long reach 10 Mbps single pair Ethernet (SPE).
The switch supports various routing configurations between
the two Ethernet ports and the SPI host port providing a flexible
solution for line, daisy-chain, or ring network topologies.

The ADIN2111 supports cable reach of up to 1700 meters with ultra
low power consumption of 77 mW. The two PHY cores support the
1.0 V p-p operating mode and the 2.4 V p-p operating mode defined
in the IEEE 802.3cg standard.

The device integrates the switch, two Ethernet physical layer (PHY)
cores with a media access control (MAC) interface and all the
associated analog circuitry, and input and output clock buffering.

The device also includes internal buffer queues, the SPI and
subsystem registers, as well as the control logic to manage the reset
and clock control and hardware pin configuration.

Access to the PHYs is exposed via an internal MDIO bus. Writes/reads
can be performed by reading/writing to the ADIN2111 MDIO registers
via SPI.

On probe, for each port, a struct net_device is allocated and
registered. When both ports are added to the same bridge, the driver
will enable offloading of frame forwarding at the hardware level.

Driver offers STP support. Normal operation on forwarding state.
Allows only frames with the 802.1d DA to be passed to the host
when in any of the other states.

When both ports of ADIN2111 belong to the same SW bridge a maximum
of 12 FDB entries will offloaded by the hardware and are marked as such.
====================

Link: https://lore.kernel.org/r/20220913122629.124546-1-andrei.tachici@stud.acs.upb.roSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Add bindings for the ADIN1110/2111 MAC-PHY/SWITCH.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The ADIN1110 is a low power single port 10BASE-T1L MAC-PHY
designed for industrial Ethernet applications. It integrates
an Ethernet PHY core with a MAC and all the associated analog
circuitry, input and output clock buffering.

ADIN1110 MAC-PHY encapsulates the ADIN1100 PHY. The PHY registers
can be accessed through the MDIO MAC registers.
We are registering an MDIO bus with custom read/write in order
to let the PHY to be discovered by the PAL. This will let
the ADIN1100 Linux driver to probe and take control of
the PHY.

The ADIN2111 is a low power, low complexity, two-Ethernet ports
switch with integrated 10BASE-T1L PHYs and one serial peripheral
interface (SPI) port.

The device is designed for industrial Ethernet applications using
low power constrained nodes and is compliant with the IEEE 802.3cg-2019
Ethernet standard for long reach 10 Mbps single pair Ethernet (SPE).
The switch supports various routing configurations between
the two Ethernet ports and the SPI host port providing a flexible
solution for line, daisy-chain, or ring network topologies.

The ADIN2111 supports cable reach of up to 1700 meters with ultra
low power consumption of 77 mW. The two PHY cores support the
1.0 V p-p operating mode and the 2.4 V p-p operating mode defined
in the IEEE 802.3cg standard.

The device integrates the switch, two Ethernet physical layer (PHY)
cores with a media access control (MAC) interface and all the
associated analog circuitry, and input and output clock buffering.

The device also includes internal buffer queues, the SPI and
subsystem registers, as well as the control logic to manage the reset
and clock control and hardware pin configuration.

Access to the PHYs is exposed via an internal MDIO bus. Writes/reads
can be performed by reading/writing to the ADIN2111 MDIO registers
via SPI.

On probe, for each port, a struct net_device is allocated and
registered. When both ports are added to the same bridge, the driver
will enable offloading of frame forwarding at the hardware level.

Driver offers STP support. Normal operation on forwarding state.
Allows only frames with the 802.1d DA to be passed to the host
when in any of the other states.

When both ports of ADIN2111 belong to the same SW bridge a maximum
of 12 FDB entries will offloaded by the hardware and are marked as such.
Co-developed-by: Lennart Franzen <lennart@lfdomain.com>
Signed-off-by: Lennart Franzen <lennart@lfdomain.com>
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Add additional PHY IDs for the internal PHYs of adin1110 and adin2111.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Andrea Mayer says:

====================
seg6: add NEXT-C-SID support for SRv6 End behavior

The Segment Routing (SR) architecture is based on loose source routing.
A list of instructions, called segments, can be added to the packet headers to
influence the forwarding and processing of the packets in an SR enabled
network.
In SRv6 (Segment Routing over IPv6 data plane) [1], the segment identifiers
(SIDs) are IPv6 addresses (128 bits) and the segment list (SID List) is carried
in the Segment Routing Header (SRH). A segment may correspond to a "behavior"
that is executed by a node when the packet is received.
The Linux kernel currently supports a large subset of the behaviors described
in [2] (e.g., End, End.X, End.T and so on).

Some SRv6 scenarios (i.e.: traffic-engineering, fast-rerouting, VPN, mobile
network backhaul, etc.) may require a large number of segments (i.e. up to 15).
Therefore, reducing the size of the SID List is useful to minimize the impact
on MTU (Maximum Transfer Unit) and to enable SRv6 on legacy hardware devices
with limited processing power that can suffer from long IPv6 headers.

Draft-ietf-spring-srv6-srh-compression [3] extends the SRv6 architecture by
providing different mechanisms for the efficient representation (i.e.
compression) of the SID List.

The NEXT-C-SID mechanism described in [3] offers the possibility of encoding
several SRv6 segments within a single 128 bit SID address. Such a SID address
is called a Compressed SID Container. In this way, the length of the SID List
can be drastically reduced. In some cases, the SRH can be omitted, as the IPv6
Destination Address can carry the whole Segment List, using its compressed
representation.

The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2].
The flavors represent additional operations that can modify or extend a subset
of the existing behaviors.

In this patchset we extend the SRv6 Subsystem in order to support the
NEXT-C-SID mechanism.

In details the patchset is made of:
 - patch 1/3: add netlink_ext_ack support in parsing SRv6 behavior attributes;
 - patch 2/3: add NEXT-C-SID support for SRv6 End behavior;
 - patch 3/3: add selftest for NEXT-C-SID in SRv6 End behavior.

The corresponding iproute2 patch for supporting the NEXT-C-SID in SRv6 End
behavior is provided in a separated patchset.

Comments, improvements and suggestions are always appreciated.

[1] - https://datatracker.ietf.org/doc/html/rfc8754
[2] - https://datatracker.ietf.org/doc/html/rfc8986
[3] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression

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

Link: https://lore.kernel.org/r/20220912171619.16943-1-andrea.mayer@uniroma2.itSigned-off-by: Paolo Abeni <pabeni@redhat.com>

This selftest is designed for testing the support of NEXT-C-SID flavor
for SRv6 End behavior. It instantiates a virtual network composed of
several nodes: hosts and SRv6 routers. Each node is realized using a
network namespace that is properly interconnected to others through veth
pairs.
The test considers SRv6 routers implementing IPv4/IPv6 L3 VPNs leveraged
by hosts for communicating with each other. Such routers i) apply
different SRv6 Policies to the traffic received from connected hosts,
considering the IPv4 or IPv6 protocols; ii) use the NEXT-C-SID
compression mechanism for encoding several SRv6 segments within a single
128-bit SID address, referred to as a Compressed SID (C-SID) container.

The NEXT-C-SID is provided as a "flavor" of the SRv6 End behavior,
enabling it to properly process the C-SID containers. The correct
execution of the enabled NEXT-C-SID SRv6 End behavior is verified
through reachability tests carried out between hosts belonging to the
same VPN.
Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Acked-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The NEXT-C-SID mechanism described in [1] offers the possibility of
encoding several SRv6 segments within a single 128 bit SID address. Such
a SID address is called a Compressed SID (C-SID) container. In this way,
the length of the SID List can be drastically reduced.

A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address
logically structured in three main blocks: i) Locator-Block; ii)
Locator-Node Function; iii) Argument.

                        C-SID container
+------------------------------------------------------------------+
|     Locator-Block      |Loc-Node|            Argument            |
|                        |Function|                                |
+------------------------------------------------------------------+
<--------- B -----------> <- NF -> <------------- A --------------->

   (i) The Locator-Block can be any IPv6 prefix available to the provider;

  (ii) The Locator-Node Function represents the node and the function to
       be triggered when a packet is received on the node;

 (iii) The Argument carries the remaining C-SIDs in the current C-SID
       container.

The NEXT-C-SID mechanism relies on the "flavors" framework defined in
[2]. The flavors represent additional operations that can modify or
extend a subset of the existing behaviors.

This patch introduces the support for flavors in SRv6 End behavior
implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID
flavor works as an End behavior but it is capable of processing the
compressed SID List encoded in C-SID containers.

An SRv6 End behavior with NEXT-C-SID flavor can be configured to support
user-provided Locator-Block and Locator-Node Function lengths. In this
implementation, such lengths must be evenly divisible by 8 (i.e. must be
byte-aligned), otherwise the kernel informs the user about invalid
values with a meaningful error code and message through netlink_ext_ack.

If Locator-Block and/or Locator-Node Function lengths are not provided
by the user during configuration of an SRv6 End behavior instance with
NEXT-C-SID flavor, the kernel will choose their default values i.e.,
32-bit Locator-Block and 16-bit Locator-Node Function.

[1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression
[2] - https://datatracker.ietf.org/doc/html/rfc8986Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

An SRv6 behavior instance can be set up using mandatory and/or optional
attributes.
In the setup phase, each supplied attribute is parsed and processed. If
the parsing operation fails, the creation of the behavior instance stops
and an error number/code is reported to the user.  In many cases, it is
challenging for the user to figure out exactly what happened by relying
only on the error code.

For this reason, we add the support for netlink_ext_ack in parsing SRv6
behavior attributes. In this way, when an SRv6 behavior attribute is
parsed and an error occurs, the kernel can send a message to the
userspace describing the error through a meaningful text message in
addition to the classic error code.
Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>