sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

Remove unused etherswitch_devclass.

[etherswitch] add the first pass of a simple API to flush and fetch the L2 address table from the ethernet switch.

This stuff may be a bit fluid during this -HEAD cycle as various other
switch features are added, but the current stuff is enough to drive
initial development and features on the atheros range of integrated
and external switches.

* add a method to flush the whole address table;
* add a method to flush all addresses on a given port;
* add a method to download the address table;
* .. and then a method to fetch entries from the address table.

The table fetch/read methods pass through to the drivers for now since
the drivers may implement different ways of fetching/caching the address
table data. The atheros devices for example fetch the table by
iterating over the table through a set of registers and so you need
to keep that locked whilst you iterate otherwise you may have the table
flushed half way by a port status change.

This is a no-op until the userland and arswitch code shows up.

sys/dev: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Convert etherswitch to use the make_dev_s(9) KPI. This fix a possible race
where si_drv1 can be accessed before it gets set.

MFC after: 3 days
Suggested by: kib
Sponsored by: Rubicon Communications, LLC (Netgate)

Allow simultaneous access to switch device, there is no reason to prevent
it.

Remove bogus wrappers and use the kernel defaults.

While here, use DEVMETHOD_END.

Obtained from: pfSense
MFC after: 2 weeks
Sponsored by: Rubicon Communications, LLC (Netgate)

Add the ability to change the vlan operation mode.

This adds a vlan capability field to etherswitch_info structure and some
definitions of ports flags.

It adds the support to global config parameters which right now is used
only to switch between the vlan modes, but it is intended to be extended
to support the setup of others parameters (STP, mirror, etc.).

Submitted by: Luiz Otavio O Souza <loos.br@gmail.com>
Reviewed by: ray

Locking for etherswitch framework:
* add lock/unlock methods;
* add lock/unlock default implementation;
* surround switch IOCTLs with locking;
* add lock/unlock implementation for arswitch;

Submitted by: Luiz Otavio O Souza
Approved by: adrian (mentor)

Commit the first pass of the etherswitch support.

This is designed to support the very basic ethernet switch chip behaviour,
specifically:

* accessing switch register space;
* accessing per-PHY registers (for switches that actually expose PHYs);
* basic vlan group support, which applies for the rtl8366 driver but not
for the atheros switches.

This also includes initial support for:

* rtl8366rb support - which is a 10/100/1000 switch which supports
vlan groups;
* Initial Atheros AR8316 switch support - which is a 10/100/1000 switch
which supports an alternate vlan configuration (so the vlan group
methods are stubbed.)

The general idea here is that the switch driver may speak to a variety of
backend busses (mdio, i2c, spi, whatever) and expose:

* If applicable, one or more MDIO busses which ethernet interfaces can
then attach PHYs to via miiproxy/mdioproxy;

* exposes miibusses, one for each port at the moment, so ..

* .. a PHY can be exposed on each miibus, for each switch port, with all
of the existing MII/ifnet framework.

However:

* The ifnet is manually created for now, and it isn't linked into the
interface list, nor can you (currently) send/receive frames on this ifnet.
At some point in the future there may be _some_ support for this, for
switches with a multi-port, isolated mode.

* I'm still in the process of sorting out correct(er) locking.

TODO:

* ray's switch code in zrouter (zrouter.org) includes a much more developed
newbus API that covers the various switch methods, as well as a
capability API so drivers, the switch layer and the userland utility
can properly control the subset of supported features.

The plan is to sort that out later, once the rest of ray's switch drivers
are brought over and extended to export MII busses and PHYs.

Submitted by: Stefan Bethke <stb@lassitu.de>
Reviewed by: ray