As we have the ability to track the PHYs connected to a net_device
through the link_topology, we can expose this list to userspace. This
allows userspace to use these identifiers for phy-specific commands and
take the decision of which PHY to target by knowing the link topology.

Add PHY_GET and PHY_DUMP, which can be a filtered DUMP operation to list
devices on only one interface.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some netlink commands are target towards ethernet PHYs, to control some
of their features. As there's several such commands, add the ability to
pass a PHY index in the ethnl request, which will populate the generic
ethnl_req_info with the passed phy_index.

Add a helper that netlink command handlers need to use to grab the
targeted PHY from the req_info. This helper needs to hold rtnl_lock()
while interacting with the PHY, as it may be removed at any point.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that we track RSS contexts in the core we can easily dump
them. This is a major introspection improvement, as previously
the only way to find all contexts would be to try all ids
(of which there may be 2^32 - 1).

Don't use the XArray iterators (like xa_for_each_start()) as they
do not move the index past the end of the array once done, which
caused multiple bugs in Netlink dumps in the past.

Reviewed-by: Edward Cree <ecree.xilinx@gmail.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 31e0aa99dc02 ("ethtool: Veto some operations during firmware flashing process")
 added a flag module_fw_flash_in_progress to struct net_device.  As
 this is ethtool related state, move it to the recently created
 struct ethtool_netdev_state, accessed via the 'ethtool' member of
 struct net_device.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20240703121849.652893-1-edward.cree@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add the ability to flash the modules' firmware by implementing the
interface between the user space and the kernel.

Example from a succeeding implementation:

 # ethtool --flash-module-firmware swp40 file test.bin

 Transceiver module firmware flashing started for device swp40
 Transceiver module firmware flashing in progress for device swp40
 Progress: 99%
 Transceiver module firmware flashing completed for device swp40

In addition, add infrastructure that allows modules to set socket-specific
private data. This ensures that when a socket is closed from user space
during the flashing process, the right socket halts sending notifications
to user space until the work item is completed.

Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some operations cannot be performed during the firmware flashing
process.

For example:

- Port must be down during the whole flashing process to avoid packet loss
  while committing reset for example.

- Writing to EEPROM interrupts the flashing process, so operations like
  ethtool dump, module reset, get and set power mode should be vetoed.

- Split port firmware flashing should be vetoed.

In order to veto those scenarios, add a flag in 'struct net_device' that
indicates when a firmware flash is taking place on the module and use it
to prevent interruptions during the process.

Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add progress notifications ability to user space while flashing modules'
firmware by implementing the interface between the user space and the
kernel.

Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

for_each_netdev_dump() can be used with RCU protection,
no need for rtnl if we are going to use dev_hold()/dev_put().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240207153514.3640952-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The default dump handler needs to clear ret before returning.
Otherwise if the last interface returns an inconsequential
error this error will propagate to user space.

This may confuse user space (ethtool CLI seems to ignore it,
but YNL doesn't). It will also terminate the dump early
for mutli-skb dump, because netlink core treats EOPNOTSUPP
as a real error.

Fixes: 728480f12442 ("ethtool: default handlers for GET requests")
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20231126225806.2143528-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We had a number of bugs in the past because developers forgot
to fully test dumps, which pass NULL as info to .prepare_data.
.prepare_data implementations would try to access info->extack
leading to a null-deref.

Now that dumps and notifications can access struct genl_info
we can pass it in, and remove the info null checks.

Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> # pause
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230814214723.2924989-11-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>