Ido Schimmel says:

====================
mlxsw: Prepare SPAN API for upcoming changes

Switched port analyzer (SPAN) is used for packet mirroring. Over mlxsw
this is achieved by attaching tc-mirred action to either matchall or
flower classifier.

The current API used to configure SPAN consists of two functions:
mlxsw_sp_span_mirror_add() and mlxsw_sp_span_mirror_del().

These two functions pack a lot of different operations:

* SPAN agent configuration: Determining the egress port and optional
  headers that need to encapsulate the mirrored packet (when mirroring
  to a gretap, for example)

* Egress mirror buffer configuration: Allocating / freeing a buffer when
  port is analyzed (inspected) at egress

* SPAN agent binding: Binding the SPAN agent to a trigger, if any. The
  current triggers are incoming / outgoing packet and they are only used
  for matchall-based mirroring

This non-modular design makes it difficult to extend the API for future
changes, such as new mirror targets (CPU) and new global triggers (early
dropped packets, for example).

Therefore, this patch set gradually adds APIs for above mentioned
operations and then converts the two existing users to use it instead of
the old API. No functional changes intended. Tested with existing
mirroring selftests.

Patch set overview:

Patches #1-#5 gradually add the new API
Patches #6-#8 convert existing users to use the new API
Patch #9 removes the old API
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove the old SPAN API now that matchall-based and flower-based
mirroring were converted to use the new API.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As previously explained, each port whose outgoing traffic is analyzed
needs to have an egress mirror buffer.

The size of the egress mirror buffer is calculated based on various
parameters, two of which are the speed and the MTU of the port.

Therefore, when the MTU or the speed of a port change, the SPAN code is
called to see if the egress mirror buffer of the port needs to be
adjusted.

Currently, this is done by traversing all the SPAN agents and for each
SPAN agent the list of bound ports is traversed.

Instead of the above, traverse the recently added list of analyzed
ports.

This will later allow us to remove the old SPAN API.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In flower-based mirroring, mirroring is done with ACLs and the SPAN
agent is not bound to a port. Instead its identifier is specified in an
ACL action.

Convert this type of mirroring to use the new API.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In matchall-based mirroring, mirroring is not done with ACLs, but a SPAN
agent is bound to the ingress / egress of a port and all incoming /
outgoing traffic is mirrored.

Convert this type of mirroring to use the new API.

First the SPAN agent is resolved, then the port is marked as analyzed
and its egress mirror buffer is potentially allocated. Lastly, the
binding is performed.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, a SPAN agent can only be bound to a per-port trigger where
the trigger is either an incoming packet (INGRESS) or an outgoing packet
(EGRESS) to / from the port.

A follow-up patch set will introduce the concept of global triggers and
per-{port, TC} enablement. With global triggers, the trigger entry is
only keyed by a trigger and not by a port and a trigger. The trigger can
be, for example, a packet that was early dropped.

While the binding between the SPAN agent and the trigger is performed
only once, the trigger entry needs to be reference counted, as the
trigger can be enabled on multiple ports.

Add APIs to bind / unbind a SPAN agent to a trigger and reference count
the trigger entry in preparation for global triggers.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The code that adjusts the egress buffer size is not symmetric at the
moment. The update is done via a call to
mlxsw_sp_span_port_buffer_update(), but the disablement is done inline
by invoking the write to SBIB register directly.

Wrap the disablement code in mlxsw_sp_span_port_buffer_disable().
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Suggested-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Next patch will introduce mlxsw_sp_span_port_buffer_disable() function
that disables the egress buffer on an analyzed port. Rename the opposite
function that updates the buffer on an analyzed port accordingly.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Suggested-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

An analyzed port is a port whose incoming / outgoing traffic is mirrored
to a SPAN agent and analyzed on a remote server.

A port can be analyzed by multiple tc filters and therefore the
corresponding analyzed port entry needs to be reference counted. This is
significant because ports whose outgoing traffic is analyzed need to
have an egress mirror buffer.

Add APIs to get / put an analyzed port. Allocate an egress mirror buffer
on a port when it is first inspected at egress and free the buffer when
it is no longer inspected at egress.

Protect the list of analyzed ports with a mutex, as a later patch will
traverse it from a context in which RTNL lock is not held.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Given a netdev that packets should be mirrored to, create a SPAN agent
and return its identifier to the caller.

The SPAN agent is reference counted, as multiple tc-mirred actions can
point to the same destination netdev.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Mauro Carvalho Chehab says:

====================
net: manually convert files to ReST format - part 2

That's the second part of my work to convert the networking
text files into ReST. it is based on today's linux-next (next-20200430).

The full series (including those ones) are at:

	https://git.linuxtv.org/mchehab/experimental.git/log/?h=net-docs

I should be sending the remaining patches (another /38 series)
after getting those merged at -next.

The documents, converted to HTML via the building system are at:

	https://www.infradead.org/~mchehab/kernel_docs/networking/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- add a document title;
- adjust titles and chapters, adding proper markups;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Not much to be done here:
- add SPDX header;
- add a document title;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Not much to be done here:

- add SPDX header;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- add a document title;
- use the right numbered list markup;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- use copyright symbol;
- adjust title markup;
- mark code blocks and literals as such;
- mark tables as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- mark tables as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- use copyright symbol;
- add a document title;
- adjust titles and chapters, adding proper markups;
- comment out text-only TOC from html/pdf output;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- mark code blocks and literals as such;
- add a document title;
- adjust chapters, adding proper markups;
- mark lists as such;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Not much to be done here:
- add SPDX header;
- add a document title;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- add a document title;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- adjust title markup;
- use autonumbered list markups;
- mark code blocks and literals as such;
- mark tables as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- add a document title;
- mark code blocks and literals as such;
- mark tables as such;
- mark lists as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- use copyright symbol;
- add a document title;
- mark code blocks and literals as such;
- mark tables as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- add a document title;
- mark code blocks and literals as such;
- mark tables as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- mark tables as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- adjust title markup;
- use bold markups on a few places;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- adjust title markup;
- use copyright symbol;
- add notes markups;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Rémi Denis-Courmont <courmisch@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch has a big diff, but most are due to whitespaces.

Yet, the conversion is similar to other files under networking:

- add SPDX header;
- add a document title;
- adjust titles and chapters, adding proper markups;
- mark lists as such;
- mark tables as such;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- add a document title;
- adjust chapters, adding proper markups;
- mark lists as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- add notes markups;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- add a document title;
- mark lists as such;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- adjust title and chapter markups;
- mark lists as such;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Not much to be done here:

- add SPDX header;
- add a document title;
- add a chapter markup;
- mark tables as such;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- adjust title markup;
- mark lists as such;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>