This switches the airtime scheduler in mac80211 to use a virtual
time-based scheduler instead of the round-robin scheduler used before.
This has a couple of advantages:

- No need to sync up the round-robin scheduler in firmware/hardware with
  the round-robin airtime scheduler.

- If several stations are eligible for transmission we can schedule both
  of them; no need to hard-block the scheduling rotation until the head
  of the queue has used up its quantum.

- The check of whether a station is eligible for transmission becomes
  simpler (in ieee80211_txq_may_transmit()).

The drawback is that scheduling becomes slightly more expensive, as we
need to maintain an rbtree of TXQs sorted by virtual time. This means
that ieee80211_register_airtime() becomes O(logN) in the number of
currently scheduled TXQs because it can change the order of the
scheduled stations. We mitigate this overhead by only resorting when a
station changes position in the tree, and hopefully N rarely grows too
big (it's only TXQs currently backlogged, not all associated stations),
so it shouldn't be too big of an issue.

To prevent divisions in the fast path, we maintain both station sums and
pre-computed reciprocals of the sums. This turns the fast-path operation
into a multiplication, with divisions only happening as the number of
active stations change (to re-compute the current sum of all active
station weights). To prevent this re-computation of the reciprocal from
happening too frequently, we use a time-based notion of station
activity, instead of updating the weight every time a station gets
scheduled or de-scheduled. As queues can oscillate between empty and
occupied quite frequently, this can significantly cut down on the number
of re-computations. It also has the added benefit of making the station
airtime calculation independent on whether the queue happened to have
drained at the time an airtime value was accounted.

Co-developed-by: Yibo Zhao <yiboz@codeaurora.org>
Signed-off-by: Yibo Zhao <yiboz@codeaurora.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20210623134755.235545-1-toke@redhat.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

In the HE capabilities, spell A-MSDU correctly, not "A-MDSU".

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210409123755.9e6ff1af1181.If6868bc6902ccd9a95c74c78f716c4b41473ef14@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The A-MPDU length exponent extension is defined differently in
802.11ax D6.1, align with that.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210409123755.c2a257d3e2df.I3455245d388c52c61dace7e7958dbed7e807cfb6@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Some names were changed, align that with the spec as of
802.11ax-D6.1.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210409123755.b1e5fbab0d8c.I3eb6076cb0714ec6aec6b8f9dee613ce4a05d825@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

This allows drivers to pass 802.3 frames to mac80211, with some restrictions:

- the skb must be passed with a valid sta
- fast-rx needs to be active for the sta
- monitor mode needs to be disabled

mac80211 will tell the driver when it is safe to enable rx decap offload for
a particular station.

In order to implement support, a driver must:

- call ieee80211_hw_set(hw, SUPPORTS_RX_DECAP_OFFLOAD)
- implement ops->sta_set_decap_offload
- mark 802.3 frames with RX_FLAG_8023

If it doesn't want to enable offload for some vif types, it can mask out
IEEE80211_OFFLOAD_DECAP_ENABLED in vif->offload_flags from within the
.add_interface or .update_vif_offload driver ops

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20201218184718.93650-6-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The macro uses should have (and already have) the semicolon.

Signed-off-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20201127193842.2876355-1-trix@redhat.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Replace commas with semicolons.  Commas introduce unnecessary
variability in the code structure and are hard to see.  What is done
is essentially described by the following Coccinelle semantic patch
(http://coccinelle.lip6.fr/):

// <smpl>
@@ expression e1,e2; @@
e1
-,
+;
e2
... when any
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Link: https://lore.kernel.org/r/1602412498-32025-3-git-send-email-Julia.Lawall@inria.fr
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Minor comment conflict in mac80211.

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

If we know that we have an encrypted link (based on having had
a key configured for TX in the past) then drop all data frames
in the key selection handler if there's no key anymore.

This fixes an issue with mac80211 internal TXQs - there we can
buffer frames for an encrypted link, but then if the key is no
longer there when they're dequeued, the frames are sent without
encryption. This happens if a station is disconnected while the
frames are still on the TXQ.

Detecting that a link should be encrypted based on a first key
having been configured for TX is fine as there are no use cases
for a connection going from with encryption to no encryption.
With extended key IDs, however, there is a case of having a key
configured for only decryption, so we can't just trigger this
behaviour on a key being configured.

Cc: stable@vger.kernel.org
Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200326150855.6865c7f28a14.I9fb1d911b064262d33e33dfba730cdeef83926ca@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Merging to get the mac80211 updates that have since propagated
into net-next.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>