sfc: do not try to call tc functions when CONFIG_SFC_SRIOV=n

Functions efx_tc_netdev_event and efx_tc_netevent_event do not exist
in that case as object files tc_bindings.o and tc_encap_actions.o
are not built, so the calls to them from ef100_netdev_event and
ef100_netevent_event cause link errors.
Wrap the corresponding header files (tc_bindings.h, tc_encap_actions.h)
with #if IS_ENABLED(CONFIG_SFC_SRIOV), and add an #else with static
inline stubs for these two functions.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202306102026.ISK5JfUQ-lkp@intel.com/
Fixes: 7e5e7d800011 ("sfc: neighbour lookup for TC encap action offload")
Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Reviewed-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sfc: neighbour lookup for TC encap action offload

For each neighbour we're interested in, create a struct efx_neigh_binder
object which has a list of all the encap_actions using it. When we
receive a neighbouring update (through the netevent notifier), find the
corresponding efx_neigh_binder and update all its users.
Since the actual generation of encap headers is still only a stub, the
resulting rules still get left on fallback actions.

Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

sfc: some plumbing towards TC encap action offload

Create software objects to manage the metadata for encap actions that
can be attached to TC rules. However, since we don't yet have the
neighbouring information (needed to generate the Ethernet header),
all rules with encap actions are marked as "unready" and thus insert
the fallback action into hardware rather than actually offloading the
encapsulation action.

Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>