net: devlink: let the core report the driver name instead of the drivers

The driver name is available in device_driver::name. Right now,
drivers still have to report this piece of information themselves in
their devlink_ops::info_get callback function.

In order to factorize code, make devlink_nl_info_fill() add the driver
name attribute.

Now that the core sets the driver name attribute, drivers are not
supposed to call devlink_info_driver_name_put() anymore. Remove
devlink_info_driver_name_put() and clean-up all the drivers using this
function in their callback.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Tested-by: Ido Schimmel <idosch@nvidia.com> # mlxsw
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: dsa: mv88e6xxx: Export STU as devlink region

Export the raw STU data in a devlink region so that it can be
inspected from userspace and compared to the current bridge
configuration.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: dsa: tear down devlink port regions when tearing down the devlink port on error

Commit 86f8b1c01a0a ("net: dsa: Do not make user port errors fatal")
decided it was fine to ignore errors on certain ports that fail to
probe, and go on with the ports that do probe fine.

Commit fb6ec87f7229 ("net: dsa: Fix type was not set for devlink port")
noticed that devlink_port_type_eth_set(dlp, dp->slave); does not get
called, and devlink notices after a timeout of 3600 seconds and prints a
WARN_ON. So it went ahead to unregister the devlink port. And because
there exists an UNUSED port flavour, we actually re-register the devlink
port as UNUSED.

Commit 08156ba430b4 ("net: dsa: Add devlink port regions support to
DSA") added devlink port regions, which are set up by the driver and not
by DSA.

When we trigger the devlink port deregistration and reregistration as
unused, devlink now prints another WARN_ON, from here:

devlink_port_unregister:
WARN_ON(!list_empty(&devlink_port->region_list));

So the port still has regions, which makes sense, because they were set
up by the driver, and the driver doesn't know we're unregistering the
devlink port.

Somebody needs to tear them down, and optionally (actually it would be
nice, to be consistent) set them up again for the new devlink port.

But DSA's layering stays in our way quite badly here.

The options I've considered are:

1. Introduce a function in devlink to just change a port's type and
flavour. No dice, devlink keeps a lot of state, it really wants the
port to not be registered when you set its parameters, so changing
anything can only be done by destroying what we currently have and
recreating it.

2. Make DSA cache the parameters passed to dsa_devlink_port_region_create,
and the region returned, keep those in a list, then when the devlink
port unregister needs to take place, the existing devlink regions are
destroyed by DSA, and we replay the creation of new regions using the
cached parameters. Problem: mv88e6xxx keeps the region pointers in
chip->ports[port].region, and these will remain stale after DSA frees
them. There are many things DSA can do, but updating mv88e6xxx's
private pointers is not one of them.

3. Just let the driver do it (i.e. introduce a very specific method
called ds->ops->port_reinit_as_unused, which unregisters its devlink
port devlink regions, then the old devlink port, then registers the
new one, then the devlink port regions for it). While it does work,
as opposed to the others, it's pretty horrible from an API
perspective and we can do better.

4. Introduce a new pair of methods, ->port_setup and ->port_teardown,
which in the case of mv88e6xxx must register and unregister the
devlink port regions. Call these 2 methods when the port must be
reinitialized as unused.

Naturally, I went for the 4th approach.

Fixes: 08156ba430b4 ("net: dsa: Add devlink port regions support to DSA")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: mv88e6xxx: Export cross-chip PVT as devlink region

Export the raw PVT data in a devlink region so that it can be
inspected from userspace and compared to the current bridge
configuration.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: mv88e6xxx: Fix off-by-one in VTU devlink region size

In the unlikely event of the VTU being loaded to the brim with 4k
entries, the last one was placed in the buffer, but the size reported
to devlink was off-by-one. Make sure that the final entry is available
to the caller.

Fixes: ca4d632aef03 ("net: dsa: mv88e6xxx: Export VTU as devlink region")
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: mv88e6xxx: Add helper to get a chip's max_vid

Most of the other chip info constants have helpers to get at them; add
one for max_vid to keep things consistent.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20201110185720.18228-1-tobias@waldekranz.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: dsa: mv88e6xxx: Fix memleak in mv88e6xxx_region_atu_snapshot

When mv88e6xxx_fid_map return error, we lost free the table.

Fix it.

Fixes: bfb255428966 ("net: dsa: mv88e6xxx: Add devlink regions")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhangxiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20201109144416.1540867-1-zhangxiaoxu5@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: dsa: mv88e6xxx: Export VTU as devlink region

Export the raw VTU data and related registers in a devlink region so
that it can be inspected from userspace and compared to the current
bridge configuration.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20201109082927.8684-1-tobias@waldekranz.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: dsa: mv88e6xxx: Add per port devlink regions

Add a devlink region to return the per port registers.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: mv88e6xxx: Implement devlink info get callback

Return the driver name and the asic.id with the switch name.

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: mv88e6xxx: Add devlink regions

Allow the global registers, and the ATU to be snapshot via devlink
regions. It is later planned to add support for the port registers.

v2:
Remove left over debug prints
Comment ATU format is generic for mv88e6xxx, not wider

v3:
Make use of ops structure passed to snapshot function
Remove port regions

v4:
Make use of enum mv88e6xxx_region_id
Fix global2/global1 read typ0

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: mv88e6xxx: Move devlink code into its own file

There will soon be more devlink code. Move the existing code into a
file of its own, before we start adding this new code.

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>