net: ethtool: create and export ethtool_dev_mm_supported()

Create a wrapper over __ethtool_dev_mm_supported() which also calls
ethnl_ops_begin() and ethnl_ops_complete(). It can be used by other code
layers, such as tc, to make sure that preemptible TCs are supported
(this is true if an underlying MAC Merge layer exists).

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ferenc Fejes <fejes@inf.elte.hu>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: ethtool: provide shims for stats aggregation helpers when CONFIG_ETHTOOL_NETLINK=n

ethtool_aggregate_*_stats() are implemented in net/ethtool/stats.c, a
file which is compiled out when CONFIG_ETHTOOL_NETLINK=n. In order to
avoid adding Kbuild dependencies from drivers (which call these helpers)
on CONFIG_ETHTOOL_NETLINK, let's add some shim definitions which simply
make the helpers dead code.

This means the function prototypes should have been located in
include/linux/ethtool_netlink.h rather than include/linux/ethtool.h.

Fixes: 449c5459641a ("net: ethtool: add helpers for aggregate statistics")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20230125110214.4127759-1-vladimir.oltean@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

ethtool: fix ethtool msg len calculation for pause stats

ETHTOOL_A_PAUSE_STAT_MAX is the MAX attribute id,
so we need to subtract non-stats and add one to
get a count (IOW -2+1 == -1).

Otherwise we'll see:

ethnl cmd 21: calculated reply length 40, but consumed 52

Fixes: 9a27a33027f2 ("ethtool: add standard pause stats")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ethtool: Fix comment mentioning typo in IS_ENABLED()

This has no code changes, but it's a typo noticed in other clean-ups,
so we might as well fix it. IS_ENABLED() takes full names, and should
have the "CONFIG_" prefix.

Reported-by: Joe Perches <joe@perches.com>
Link: https://lore.kernel.org/lkml/b08611018fdb6d88757c6008a5c02fa0e07b32fb.camel@perches.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ethtool: Add helpers for cable test TDR data

Add helpers for returning raw TDR helpers in netlink messages.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ethtool: Add generic parts of cable test TDR

Add the generic parts of the code used to trigger a cable test and
return raw TDR data. Any PHY driver which support this must implement
the new driver op.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>

v2
Update nxp-tja11xx for API change.

Signed-off-by: David S. Miller <davem@davemloft.net>

net: ethtool: Add helpers for reporting test results

The PHY drivers can use these helpers for reporting the results. The
results get translated into netlink attributes which are added to the
pre-allocated skbuf.

v3:
Poison phydev->skb
Return -EMSGSIZE when ethnl_bcastmsg_put() fails
Return valid error code when nla_nest_start() fails
Use u8 for results
Actually put u32 length into message

v4:
s/ENOTSUPP/EOPNOTSUPP/g

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: ethtool: Add infrastructure for reporting cable test results

Provide infrastructure for PHY drivers to report the cable test
results. A netlink skb is associated to the phydev. Helpers will be
added which can add results to this skb. Once the test has finished
the results are sent to user space.

When netlink ethtool is not part of the kernel configuration stubs are
provided. It is also impossible to trigger a cable test, so the error
code returned by the alloc function is of no consequence.

v2:
Include the status complete in the netlink notification message

v4:
Replace -EINVAL with -EMSGSIZE

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

ethtool: provide link mode information with LINKMODES_GET request

Implement LINKMODES_GET netlink request to get link modes related
information provided by ETHTOOL_GLINKSETTINGS and ETHTOOL_GSET ioctl
commands.

This request provides supported, advertised and peer advertised link modes,
autonegotiation flag, speed and duplex.

LINKMODES_GET request can be used with NLM_F_DUMP (without device
identification) to request the information for all devices in current
network namespace providing the data.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ethtool: support for netlink notifications

Add infrastructure for ethtool netlink notifications. There is only one
multicast group "monitor" which is used to notify userspace about changes
and actions performed. Notification messages (types using suffix _NTF)
share the format with replies to GET requests.

Notifications are supposed to be broadcasted on every configuration change,
whether it is done using the netlink interface or ioctl one. Netlink SET
requests only trigger a notification if some data is actually changed.

To trigger an ethtool notification, both ethtool netlink and external code
use ethtool_notify() helper. This helper requires RTNL to be held and may
sleep. Handlers sending messages for specific notification message types
are registered in ethnl_notify_handlers array. As notifications can be
triggered from other code, ethnl_ok flag is used to prevent an attempt to
send notification before genetlink family is registered.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ethtool: introduce ethtool netlink interface

Basic genetlink and init infrastructure for the netlink interface, register
genetlink family "ethtool". Add CONFIG_ETHTOOL_NETLINK Kconfig option to
make the build optional. Add initial overall interface description into
Documentation/networking/ethtool-netlink.rst, further patches will add more
detailed information.

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