nfp: flower: offload tc flows of multiple conntrack zones

If goto_chain action present in the post ct flow rule, merge flow rules
in this ct-zone, create a new pre_ct entry as the pre ct flow rule of
next ct-zone, but do not offload merged flow rules to firmware. Repeat
the process in the next ct-zone until no goto_chain action present in
the post ct flow rule in a certain ct-zone, merged all the flow rules.
Offload to firmware finally.

Signed-off-by: Wentao Jia <wentao.jia@corigine.com>
Acked-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

nfp: flower: add goto_chain_index for ct entry

The chain_index has different means in pre ct entry and post ct entry.
In pre ct entry, it means chain index, but in post ct entry, it means
goto chain index, it is confused.

chain_index and goto_chain_index may be present in one flow rule, It
cannot be distinguished by one field chain_index, both chain_index
and goto_chain_index are required in the follow-up patch to support
multiple ct zones

Another field goto_chain_index is added to record the goto chain index.
If no goto action in post ct entry, goto_chain_index is 0.

Signed-off-by: Wentao Jia <wentao.jia@corigine.com>
Acked-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

nfp: flower: support hw offload for ct nat action

support ct nat action when pre_ct merge with post_ct
and nft. at the same time, add the extra checksum action
and hardware stats for nft to meet the action check when
do nat.

Signed-off-by: Hui Zhou <hui.zhou@corigine.com>
Reviewed-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

nfp: flower-tc: add flow stats updates for ct

Add in the logic to update flow stats. The flow stats from the nfp
is saved in the flow_pay struct, which is associated with the final
merged flow. This saves deltas however, so once read it needs to
be cleared. However the flow stats requests from the kernel is
from the other side of the chain, and a single tc flow from
the kernel can be merged into multiple other tc flows to form
multiple offloaded flows. This means that all linked flows
needs to be updated for each stats request.

Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: flower-ct: calculate required key_layers

This calculates the correct combined keylayers and key_layer_size
for the to-be-offloaded flow.

Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: flower-ct: fill in ct merge check function

Replace merge check stub code with the actual implementation. This
checks that the match parts of two tc flows does not conflict.
Only overlapping keys needs to be checked, and only the narrowest
masked parts needs to be checked, so each key is masked with the
AND'd result of both masks before comparing.

Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: flower-ct: add nft_merge table

Add table and struct to save the result of the three-way merge
between pre_ct,post_ct, and nft flows. Merging code is to be
added in follow-up patches.

Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: flower-ct: add nft flows to nft list

Implement code to add and remove nft flows to the relevant list.
Registering and deregistering the callback function for the nft
table is quite complicated. The safest is to delete the callback
on the removal of the last pre_ct flow. This is because if this
is also the latest pre_ct flow in software it means that this
specific nft table will be freed, so there will not be a later
opportunity to do this. Another place where it looks possible
to delete the callback is when the last nft_flow is deleted,
but this happens under the flow_table lock, which is also taken
when deregistering the callback, leading to a deadlock situation.

This means the final solution here is to delete the callback
when removing the last pre_ct flow, and then clean up any
remaining nft_flow entries which may still be present, since
there will never be a callback now to do this, leaving them
orphaned if not cleaned up here as well.

Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: flower-ct: add nft callback stubs

Add register/unregister of the nft callback. For now just add
stub code to accept the flows, but don't do anything with it.
Decided to accept the flows since netfilter will keep on trying
to offload a flow if it was rejected, which is quite noisy.
Follow-up patches will start implementing the functions to add
nft flows to the relevant tables.

Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: flower-ct: add delete flow handling for ct

Add functions to handle delete flow callbacks for ct flows. Also
accept the flows for offloading by returning 0 instead of -EOPNOTSUPP.
Flows will still not actually be offloaded to hw, but at this point
it's difficult to not accept the flows and also exercise the cleanup
paths properly. Traffic will still be handled safely through the
fallback path.

Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: flower-ct: add tc_merge_tb

Add the table required to store the merge result of pre_ct and post_ct
flows. This is just the initial setup and teardown of the table,
the implementation will be in follow-up patches.

Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: flower-ct: add a table to map flow cookies to ct flows

Add a hashtable which contains entries to map flow cookies to ct
flow entries. Currently the entries are added and not used, but
follow-up patches will use this for stats updates and flow deletes.

Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: flower-ct: add nfp_fl_ct_flow_entries

This commit starts adding the structures and lists that will
be used in follow up commits to enable offloading of conntrack.
Some stub functions are also introduced as placeholders by
this commit.

Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: flower-ct: add ct zone table

Add initial zone table to nfp_flower_priv. This table will be used
to store all the information required to offload conntrack.

Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: flower-ct: add pre and post ct checks

Add checks to see if a flow is a conntrack flow we can potentially
handle. Just stub out the handling the different conntrack flows.

Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>