--- /dev/null
+From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
+Date: Wed, 23 Jun 2021 15:47:55 +0200
+Subject: [PATCH] mac80211: Switch to a virtual time-based airtime scheduler
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+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>
+---
+
+--- a/include/net/mac80211.h
++++ b/include/net/mac80211.h
+@@ -6557,9 +6557,6 @@ static inline void ieee80211_txq_schedul
+ {
+ }
+
+-void __ieee80211_schedule_txq(struct ieee80211_hw *hw,
+- struct ieee80211_txq *txq, bool force);
+-
+ /**
+ * ieee80211_schedule_txq - schedule a TXQ for transmission
+ *
+@@ -6572,11 +6569,7 @@ void __ieee80211_schedule_txq(struct iee
+ * The driver may call this function if it has buffered packets for
+ * this TXQ internally.
+ */
+-static inline void
+-ieee80211_schedule_txq(struct ieee80211_hw *hw, struct ieee80211_txq *txq)
+-{
+- __ieee80211_schedule_txq(hw, txq, true);
+-}
++void ieee80211_schedule_txq(struct ieee80211_hw *hw, struct ieee80211_txq *txq);
+
+ /**
+ * ieee80211_return_txq - return a TXQ previously acquired by ieee80211_next_txq()
+@@ -6588,12 +6581,8 @@ ieee80211_schedule_txq(struct ieee80211_
+ * The driver may set force=true if it has buffered packets for this TXQ
+ * internally.
+ */
+-static inline void
+-ieee80211_return_txq(struct ieee80211_hw *hw, struct ieee80211_txq *txq,
+- bool force)
+-{
+- __ieee80211_schedule_txq(hw, txq, force);
+-}
++void ieee80211_return_txq(struct ieee80211_hw *hw, struct ieee80211_txq *txq,
++ bool force);
+
+ /**
+ * ieee80211_txq_may_transmit - check whether TXQ is allowed to transmit
+--- a/net/mac80211/cfg.c
++++ b/net/mac80211/cfg.c
+@@ -1461,6 +1461,38 @@ static void sta_apply_mesh_params(struct
+ #endif
+ }
+
++static void sta_apply_airtime_params(struct ieee80211_local *local,
++ struct sta_info *sta,
++ struct station_parameters *params)
++{
++ u8 ac;
++
++ for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
++ struct airtime_sched_info *air_sched = &local->airtime[ac];
++ struct airtime_info *air_info = &sta->airtime[ac];
++ struct txq_info *txqi;
++ u8 tid;
++
++ spin_lock_bh(&air_sched->lock);
++ for (tid = 0; tid < IEEE80211_NUM_TIDS + 1; tid++) {
++ if (air_info->weight == params->airtime_weight ||
++ !sta->sta.txq[tid] ||
++ ac != ieee80211_ac_from_tid(tid))
++ continue;
++
++ airtime_weight_set(air_info, params->airtime_weight);
++
++ txqi = to_txq_info(sta->sta.txq[tid]);
++ if (RB_EMPTY_NODE(&txqi->schedule_order))
++ continue;
++
++ ieee80211_update_airtime_weight(local, air_sched,
++ 0, true);
++ }
++ spin_unlock_bh(&air_sched->lock);
++ }
++}
++
+ static int sta_apply_parameters(struct ieee80211_local *local,
+ struct sta_info *sta,
+ struct station_parameters *params)
+@@ -1648,7 +1680,8 @@ static int sta_apply_parameters(struct i
+ sta_apply_mesh_params(local, sta, params);
+
+ if (params->airtime_weight)
+- sta->airtime_weight = params->airtime_weight;
++ sta_apply_airtime_params(local, sta, params);
++
+
+ /* set the STA state after all sta info from usermode has been set */
+ if (test_sta_flag(sta, WLAN_STA_TDLS_PEER) ||
+--- a/net/mac80211/debugfs.c
++++ b/net/mac80211/debugfs.c
+@@ -216,14 +216,14 @@ static ssize_t aql_txq_limit_read(struct
+ "VI %u %u\n"
+ "BE %u %u\n"
+ "BK %u %u\n",
+- local->aql_txq_limit_low[IEEE80211_AC_VO],
+- local->aql_txq_limit_high[IEEE80211_AC_VO],
+- local->aql_txq_limit_low[IEEE80211_AC_VI],
+- local->aql_txq_limit_high[IEEE80211_AC_VI],
+- local->aql_txq_limit_low[IEEE80211_AC_BE],
+- local->aql_txq_limit_high[IEEE80211_AC_BE],
+- local->aql_txq_limit_low[IEEE80211_AC_BK],
+- local->aql_txq_limit_high[IEEE80211_AC_BK]);
++ local->airtime[IEEE80211_AC_VO].aql_txq_limit_low,
++ local->airtime[IEEE80211_AC_VO].aql_txq_limit_high,
++ local->airtime[IEEE80211_AC_VI].aql_txq_limit_low,
++ local->airtime[IEEE80211_AC_VI].aql_txq_limit_high,
++ local->airtime[IEEE80211_AC_BE].aql_txq_limit_low,
++ local->airtime[IEEE80211_AC_BE].aql_txq_limit_high,
++ local->airtime[IEEE80211_AC_BK].aql_txq_limit_low,
++ local->airtime[IEEE80211_AC_BK].aql_txq_limit_high);
+ return simple_read_from_buffer(user_buf, count, ppos,
+ buf, len);
+ }
+@@ -255,11 +255,11 @@ static ssize_t aql_txq_limit_write(struc
+ if (ac >= IEEE80211_NUM_ACS)
+ return -EINVAL;
+
+- q_limit_low_old = local->aql_txq_limit_low[ac];
+- q_limit_high_old = local->aql_txq_limit_high[ac];
++ q_limit_low_old = local->airtime[ac].aql_txq_limit_low;
++ q_limit_high_old = local->airtime[ac].aql_txq_limit_high;
+
+- local->aql_txq_limit_low[ac] = q_limit_low;
+- local->aql_txq_limit_high[ac] = q_limit_high;
++ local->airtime[ac].aql_txq_limit_low = q_limit_low;
++ local->airtime[ac].aql_txq_limit_high = q_limit_high;
+
+ mutex_lock(&local->sta_mtx);
+ list_for_each_entry(sta, &local->sta_list, list) {
+@@ -382,6 +382,46 @@ static const struct file_operations forc
+ .llseek = default_llseek,
+ };
+
++static ssize_t airtime_read(struct file *file,
++ char __user *user_buf,
++ size_t count,
++ loff_t *ppos)
++{
++ struct ieee80211_local *local = file->private_data;
++ char buf[200];
++ u64 v_t[IEEE80211_NUM_ACS];
++ u64 wt[IEEE80211_NUM_ACS];
++ int len = 0, ac;
++
++ for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
++ spin_lock_bh(&local->airtime[ac].lock);
++ v_t[ac] = local->airtime[ac].v_t;
++ wt[ac] = local->airtime[ac].weight_sum;
++ spin_unlock_bh(&local->airtime[ac].lock);
++ }
++ len = scnprintf(buf, sizeof(buf),
++ "\tVO VI BE BK\n"
++ "Virt-t\t%-10llu %-10llu %-10llu %-10llu\n"
++ "Weight\t%-10llu %-10llu %-10llu %-10llu\n",
++ v_t[0],
++ v_t[1],
++ v_t[2],
++ v_t[3],
++ wt[0],
++ wt[1],
++ wt[2],
++ wt[3]);
++
++ return simple_read_from_buffer(user_buf, count, ppos,
++ buf, len);
++}
++
++static const struct file_operations airtime_ops = {
++ .read = airtime_read,
++ .open = simple_open,
++ .llseek = default_llseek,
++};
++
+ #ifdef CONFIG_PM
+ static ssize_t reset_write(struct file *file, const char __user *user_buf,
+ size_t count, loff_t *ppos)
+@@ -624,7 +664,11 @@ void debugfs_hw_add(struct ieee80211_loc
+ if (local->ops->wake_tx_queue)
+ DEBUGFS_ADD_MODE(aqm, 0600);
+
+- DEBUGFS_ADD_MODE(airtime_flags, 0600);
++ if (wiphy_ext_feature_isset(local->hw.wiphy,
++ NL80211_EXT_FEATURE_AIRTIME_FAIRNESS)) {
++ DEBUGFS_ADD_MODE(airtime, 0600);
++ DEBUGFS_ADD_MODE(airtime_flags, 0600);
++ }
+
+ DEBUGFS_ADD(aql_txq_limit);
+ debugfs_create_u32("aql_threshold", 0600,
+--- a/net/mac80211/debugfs_netdev.c
++++ b/net/mac80211/debugfs_netdev.c
+@@ -513,6 +513,34 @@ static ssize_t ieee80211_if_fmt_aqm(
+ }
+ IEEE80211_IF_FILE_R(aqm);
+
++static ssize_t ieee80211_if_fmt_airtime(
++ const struct ieee80211_sub_if_data *sdata, char *buf, int buflen)
++{
++ struct ieee80211_local *local = sdata->local;
++ struct ieee80211_txq *txq = sdata->vif.txq;
++ struct airtime_info *air_info;
++ int len;
++
++ if (!txq)
++ return 0;
++
++ spin_lock_bh(&local->airtime[txq->ac].lock);
++ air_info = to_airtime_info(txq);
++ len = scnprintf(buf,
++ buflen,
++ "RX: %llu us\nTX: %llu us\nWeight: %u\n"
++ "Virt-T: %lld us\n",
++ air_info->rx_airtime,
++ air_info->tx_airtime,
++ air_info->weight,
++ air_info->v_t);
++ spin_unlock_bh(&local->airtime[txq->ac].lock);
++
++ return len;
++}
++
++IEEE80211_IF_FILE_R(airtime);
++
+ IEEE80211_IF_FILE(multicast_to_unicast, u.ap.multicast_to_unicast, HEX);
+
+ /* IBSS attributes */
+@@ -661,8 +689,10 @@ static void add_common_files(struct ieee
+
+ if (sdata->local->ops->wake_tx_queue &&
+ sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
+- sdata->vif.type != NL80211_IFTYPE_NAN)
++ sdata->vif.type != NL80211_IFTYPE_NAN) {
+ DEBUGFS_ADD(aqm);
++ DEBUGFS_ADD(airtime);
++ }
+ }
+
+ static void add_sta_files(struct ieee80211_sub_if_data *sdata)
+--- a/net/mac80211/debugfs_sta.c
++++ b/net/mac80211/debugfs_sta.c
+@@ -202,7 +202,7 @@ static ssize_t sta_airtime_read(struct f
+ size_t bufsz = 400;
+ char *buf = kzalloc(bufsz, GFP_KERNEL), *p = buf;
+ u64 rx_airtime = 0, tx_airtime = 0;
+- s64 deficit[IEEE80211_NUM_ACS];
++ u64 v_t[IEEE80211_NUM_ACS];
+ ssize_t rv;
+ int ac;
+
+@@ -210,18 +210,18 @@ static ssize_t sta_airtime_read(struct f
+ return -ENOMEM;
+
+ for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
+- spin_lock_bh(&local->active_txq_lock[ac]);
++ spin_lock_bh(&local->airtime[ac].lock);
+ rx_airtime += sta->airtime[ac].rx_airtime;
+ tx_airtime += sta->airtime[ac].tx_airtime;
+- deficit[ac] = sta->airtime[ac].deficit;
+- spin_unlock_bh(&local->active_txq_lock[ac]);
++ v_t[ac] = sta->airtime[ac].v_t;
++ spin_unlock_bh(&local->airtime[ac].lock);
+ }
+
+ p += scnprintf(p, bufsz + buf - p,
+ "RX: %llu us\nTX: %llu us\nWeight: %u\n"
+- "Deficit: VO: %lld us VI: %lld us BE: %lld us BK: %lld us\n",
+- rx_airtime, tx_airtime, sta->airtime_weight,
+- deficit[0], deficit[1], deficit[2], deficit[3]);
++ "Virt-T: VO: %lld us VI: %lld us BE: %lld us BK: %lld us\n",
++ rx_airtime, tx_airtime, sta->airtime[0].weight,
++ v_t[0], v_t[1], v_t[2], v_t[3]);
+
+ rv = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
+ kfree(buf);
+@@ -236,11 +236,11 @@ static ssize_t sta_airtime_write(struct
+ int ac;
+
+ for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
+- spin_lock_bh(&local->active_txq_lock[ac]);
++ spin_lock_bh(&local->airtime[ac].lock);
+ sta->airtime[ac].rx_airtime = 0;
+ sta->airtime[ac].tx_airtime = 0;
+- sta->airtime[ac].deficit = sta->airtime_weight;
+- spin_unlock_bh(&local->active_txq_lock[ac]);
++ sta->airtime[ac].v_t = 0;
++ spin_unlock_bh(&local->airtime[ac].lock);
+ }
+
+ return count;
+@@ -263,10 +263,10 @@ static ssize_t sta_aql_read(struct file
+ return -ENOMEM;
+
+ for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
+- spin_lock_bh(&local->active_txq_lock[ac]);
++ spin_lock_bh(&local->airtime[ac].lock);
+ q_limit_l[ac] = sta->airtime[ac].aql_limit_low;
+ q_limit_h[ac] = sta->airtime[ac].aql_limit_high;
+- spin_unlock_bh(&local->active_txq_lock[ac]);
++ spin_unlock_bh(&local->airtime[ac].lock);
+ q_depth[ac] = atomic_read(&sta->airtime[ac].aql_tx_pending);
+ }
+
+--- a/net/mac80211/ieee80211_i.h
++++ b/net/mac80211/ieee80211_i.h
+@@ -840,20 +840,16 @@ enum txq_info_flags {
+ * @def_flow: used as a fallback flow when a packet destined to @tin hashes to
+ * a fq_flow which is already owned by a different tin
+ * @def_cvars: codel vars for @def_flow
+- * @frags: used to keep fragments created after dequeue
+ * @schedule_order: used with ieee80211_local->active_txqs
+- * @schedule_round: counter to prevent infinite loops on TXQ scheduling
++ * @frags: used to keep fragments created after dequeue
+ */
+ struct txq_info {
+ struct fq_tin tin;
+ struct codel_vars def_cvars;
+ struct codel_stats cstats;
+-
+- u16 schedule_round;
+- struct list_head schedule_order;
++ struct rb_node schedule_order;
+
+ struct sk_buff_head frags;
+-
+ unsigned long flags;
+
+ /* keep last! */
+@@ -930,6 +926,8 @@ struct ieee80211_sub_if_data {
+ struct ieee80211_tx_queue_params tx_conf[IEEE80211_NUM_ACS];
+ struct mac80211_qos_map __rcu *qos_map;
+
++ struct airtime_info airtime[IEEE80211_NUM_ACS];
++
+ struct work_struct csa_finalize_work;
+ bool csa_block_tx; /* write-protected by sdata_lock and local->mtx */
+ struct cfg80211_chan_def csa_chandef;
+@@ -1143,6 +1141,44 @@ enum mac80211_scan_state {
+ SCAN_ABORT,
+ };
+
++/**
++ * struct airtime_sched_info - state used for airtime scheduling and AQL
++ *
++ * @lock: spinlock that protects all the fields in this struct
++ * @active_txqs: rbtree of currently backlogged queues, sorted by virtual time
++ * @schedule_pos: the current position maintained while a driver walks the tree
++ * with ieee80211_next_txq()
++ * @active_list: list of struct airtime_info structs that were active within
++ * the last AIRTIME_ACTIVE_DURATION (100 ms), used to compute
++ * weight_sum
++ * @last_weight_update: used for rate limiting walking active_list
++ * @last_schedule_time: tracks the last time a transmission was scheduled; used
++ * for catching up v_t if no stations are eligible for
++ * transmission.
++ * @v_t: global virtual time; queues with v_t < this are eligible for
++ * transmission
++ * @weight_sum: total sum of all active stations used for dividing airtime
++ * @weight_sum_reciprocal: reciprocal of weight_sum (to avoid divisions in fast
++ * path - see comment above
++ * IEEE80211_RECIPROCAL_DIVISOR_64)
++ * @aql_txq_limit_low: AQL limit when total outstanding airtime
++ * is < IEEE80211_AQL_THRESHOLD
++ * @aql_txq_limit_high: AQL limit when total outstanding airtime
++ * is > IEEE80211_AQL_THRESHOLD
++ */
++struct airtime_sched_info {
++ spinlock_t lock;
++ struct rb_root_cached active_txqs;
++ struct rb_node *schedule_pos;
++ struct list_head active_list;
++ u64 last_weight_update;
++ u64 last_schedule_activity;
++ u64 v_t;
++ u64 weight_sum;
++ u64 weight_sum_reciprocal;
++ u32 aql_txq_limit_low;
++ u32 aql_txq_limit_high;
++};
+ DECLARE_STATIC_KEY_FALSE(aql_disable);
+
+ struct ieee80211_local {
+@@ -1156,13 +1192,8 @@ struct ieee80211_local {
+ struct codel_params cparams;
+
+ /* protects active_txqs and txqi->schedule_order */
+- spinlock_t active_txq_lock[IEEE80211_NUM_ACS];
+- struct list_head active_txqs[IEEE80211_NUM_ACS];
+- u16 schedule_round[IEEE80211_NUM_ACS];
+-
++ struct airtime_sched_info airtime[IEEE80211_NUM_ACS];
+ u16 airtime_flags;
+- u32 aql_txq_limit_low[IEEE80211_NUM_ACS];
+- u32 aql_txq_limit_high[IEEE80211_NUM_ACS];
+ u32 aql_threshold;
+ atomic_t aql_total_pending_airtime;
+
+@@ -1581,6 +1612,125 @@ static inline bool txq_has_queue(struct
+ return !(skb_queue_empty(&txqi->frags) && !txqi->tin.backlog_packets);
+ }
+
++static inline struct airtime_info *to_airtime_info(struct ieee80211_txq *txq)
++{
++ struct ieee80211_sub_if_data *sdata;
++ struct sta_info *sta;
++
++ if (txq->sta) {
++ sta = container_of(txq->sta, struct sta_info, sta);
++ return &sta->airtime[txq->ac];
++ }
++
++ sdata = vif_to_sdata(txq->vif);
++ return &sdata->airtime[txq->ac];
++}
++
++/* To avoid divisions in the fast path, we keep pre-computed reciprocals for
++ * airtime weight calculations. There are two different weights to keep track
++ * of: The per-station weight and the sum of weights per phy.
++ *
++ * For the per-station weights (kept in airtime_info below), we use 32-bit
++ * reciprocals with a devisor of 2^19. This lets us keep the multiplications and
++ * divisions for the station weights as 32-bit operations at the cost of a bit
++ * of rounding error for high weights; but the choice of divisor keeps rounding
++ * errors <10% for weights <2^15, assuming no more than 8ms of airtime is
++ * reported at a time.
++ *
++ * For the per-phy sum of weights the values can get higher, so we use 64-bit
++ * operations for those with a 32-bit divisor, which should avoid any
++ * significant rounding errors.
++ */
++#define IEEE80211_RECIPROCAL_DIVISOR_64 0x100000000ULL
++#define IEEE80211_RECIPROCAL_SHIFT_64 32
++#define IEEE80211_RECIPROCAL_DIVISOR_32 0x80000U
++#define IEEE80211_RECIPROCAL_SHIFT_32 19
++
++static inline void airtime_weight_set(struct airtime_info *air_info, u16 weight)
++{
++ if (air_info->weight == weight)
++ return;
++
++ air_info->weight = weight;
++ if (weight) {
++ air_info->weight_reciprocal =
++ IEEE80211_RECIPROCAL_DIVISOR_32 / weight;
++ } else {
++ air_info->weight_reciprocal = 0;
++ }
++}
++
++static inline void airtime_weight_sum_set(struct airtime_sched_info *air_sched,
++ int weight_sum)
++{
++ if (air_sched->weight_sum == weight_sum)
++ return;
++
++ air_sched->weight_sum = weight_sum;
++ if (air_sched->weight_sum) {
++ air_sched->weight_sum_reciprocal = IEEE80211_RECIPROCAL_DIVISOR_64;
++ do_div(air_sched->weight_sum_reciprocal, air_sched->weight_sum);
++ } else {
++ air_sched->weight_sum_reciprocal = 0;
++ }
++}
++
++/* A problem when trying to enforce airtime fairness is that we want to divide
++ * the airtime between the currently *active* stations. However, basing this on
++ * the instantaneous queue state of stations doesn't work, as queues tend to
++ * oscillate very quickly between empty and occupied, leading to the scheduler
++ * thinking only a single station is active when deciding whether to allow
++ * transmission (and thus not throttling correctly).
++ *
++ * To fix this we use a timer-based notion of activity: a station is considered
++ * active if it has been scheduled within the last 100 ms; we keep a separate
++ * list of all the stations considered active in this manner, and lazily update
++ * the total weight of active stations from this list (filtering the stations in
++ * the list by their 'last active' time).
++ *
++ * We add one additional safeguard to guard against stations that manage to get
++ * scheduled every 100 ms but don't transmit a lot of data, and thus don't use
++ * up any airtime. Such stations would be able to get priority for an extended
++ * period of time if they do start transmitting at full capacity again, and so
++ * we add an explicit maximum for how far behind a station is allowed to fall in
++ * the virtual airtime domain. This limit is set to a relatively high value of
++ * 20 ms because the main mechanism for catching up idle stations is the active
++ * state as described above; i.e., the hard limit should only be hit in
++ * pathological cases.
++ */
++#define AIRTIME_ACTIVE_DURATION (100 * NSEC_PER_MSEC)
++#define AIRTIME_MAX_BEHIND 20000 /* 20 ms */
++
++static inline bool airtime_is_active(struct airtime_info *air_info, u64 now)
++{
++ return air_info->last_scheduled >= now - AIRTIME_ACTIVE_DURATION;
++}
++
++static inline void airtime_set_active(struct airtime_sched_info *air_sched,
++ struct airtime_info *air_info, u64 now)
++{
++ air_info->last_scheduled = now;
++ air_sched->last_schedule_activity = now;
++ list_move_tail(&air_info->list, &air_sched->active_list);
++}
++
++static inline bool airtime_catchup_v_t(struct airtime_sched_info *air_sched,
++ u64 v_t, u64 now)
++{
++ air_sched->v_t = v_t;
++ return true;
++}
++
++static inline void init_airtime_info(struct airtime_info *air_info,
++ struct airtime_sched_info *air_sched)
++{
++ atomic_set(&air_info->aql_tx_pending, 0);
++ air_info->aql_limit_low = air_sched->aql_txq_limit_low;
++ air_info->aql_limit_high = air_sched->aql_txq_limit_high;
++ airtime_weight_set(air_info, IEEE80211_DEFAULT_AIRTIME_WEIGHT);
++ INIT_LIST_HEAD(&air_info->list);
++}
++
+ static inline int ieee80211_bssid_match(const u8 *raddr, const u8 *addr)
+ {
+ return ether_addr_equal(raddr, addr) ||
+@@ -1821,6 +1971,14 @@ int ieee80211_tx_control_port(struct wip
+ u64 *cookie);
+ int ieee80211_probe_mesh_link(struct wiphy *wiphy, struct net_device *dev,
+ const u8 *buf, size_t len);
++void ieee80211_resort_txq(struct ieee80211_hw *hw,
++ struct ieee80211_txq *txq);
++void ieee80211_unschedule_txq(struct ieee80211_hw *hw,
++ struct ieee80211_txq *txq,
++ bool purge);
++void ieee80211_update_airtime_weight(struct ieee80211_local *local,
++ struct airtime_sched_info *air_sched,
++ u64 now, bool force);
+
+ /* HT */
+ void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
+--- a/net/mac80211/iface.c
++++ b/net/mac80211/iface.c
+@@ -2088,6 +2088,9 @@ int ieee80211_if_add(struct ieee80211_lo
+ }
+ }
+
++ for (i = 0; i < IEEE80211_NUM_ACS; i++)
++ init_airtime_info(&sdata->airtime[i], &local->airtime[i]);
++
+ ieee80211_set_default_queues(sdata);
+
+ sdata->ap_power_level = IEEE80211_UNSET_POWER_LEVEL;
+--- a/net/mac80211/main.c
++++ b/net/mac80211/main.c
+@@ -693,10 +693,13 @@ struct ieee80211_hw *ieee80211_alloc_hw_
+ spin_lock_init(&local->queue_stop_reason_lock);
+
+ for (i = 0; i < IEEE80211_NUM_ACS; i++) {
+- INIT_LIST_HEAD(&local->active_txqs[i]);
+- spin_lock_init(&local->active_txq_lock[i]);
+- local->aql_txq_limit_low[i] = IEEE80211_DEFAULT_AQL_TXQ_LIMIT_L;
+- local->aql_txq_limit_high[i] =
++ struct airtime_sched_info *air_sched = &local->airtime[i];
++
++ air_sched->active_txqs = RB_ROOT_CACHED;
++ INIT_LIST_HEAD(&air_sched->active_list);
++ spin_lock_init(&air_sched->lock);
++ air_sched->aql_txq_limit_low = IEEE80211_DEFAULT_AQL_TXQ_LIMIT_L;
++ air_sched->aql_txq_limit_high =
+ IEEE80211_DEFAULT_AQL_TXQ_LIMIT_H;
+ }
+
+--- a/net/mac80211/rx.c
++++ b/net/mac80211/rx.c
+@@ -1573,12 +1573,8 @@ static void sta_ps_start(struct sta_info
+
+ for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
+ struct ieee80211_txq *txq = sta->sta.txq[tid];
+- struct txq_info *txqi = to_txq_info(txq);
+
+- spin_lock(&local->active_txq_lock[txq->ac]);
+- if (!list_empty(&txqi->schedule_order))
+- list_del_init(&txqi->schedule_order);
+- spin_unlock(&local->active_txq_lock[txq->ac]);
++ ieee80211_unschedule_txq(&local->hw, txq, false);
+
+ if (txq_has_queue(txq))
+ set_bit(tid, &sta->txq_buffered_tids);
+--- a/net/mac80211/sta_info.c
++++ b/net/mac80211/sta_info.c
+@@ -426,15 +426,11 @@ struct sta_info *sta_info_alloc(struct i
+ if (sta_prepare_rate_control(local, sta, gfp))
+ goto free_txq;
+
+- sta->airtime_weight = IEEE80211_DEFAULT_AIRTIME_WEIGHT;
+
+ for (i = 0; i < IEEE80211_NUM_ACS; i++) {
+ skb_queue_head_init(&sta->ps_tx_buf[i]);
+ skb_queue_head_init(&sta->tx_filtered[i]);
+- sta->airtime[i].deficit = sta->airtime_weight;
+- atomic_set(&sta->airtime[i].aql_tx_pending, 0);
+- sta->airtime[i].aql_limit_low = local->aql_txq_limit_low[i];
+- sta->airtime[i].aql_limit_high = local->aql_txq_limit_high[i];
++ init_airtime_info(&sta->airtime[i], &local->airtime[i]);
+ }
+
+ for (i = 0; i < IEEE80211_NUM_TIDS; i++)
+@@ -1893,24 +1889,59 @@ void ieee80211_sta_set_buffered(struct i
+ }
+ EXPORT_SYMBOL(ieee80211_sta_set_buffered);
+
+-void ieee80211_sta_register_airtime(struct ieee80211_sta *pubsta, u8 tid,
+- u32 tx_airtime, u32 rx_airtime)
++void ieee80211_register_airtime(struct ieee80211_txq *txq,
++ u32 tx_airtime, u32 rx_airtime)
+ {
+- struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
+- struct ieee80211_local *local = sta->sdata->local;
+- u8 ac = ieee80211_ac_from_tid(tid);
++ struct ieee80211_sub_if_data *sdata = vif_to_sdata(txq->vif);
++ struct ieee80211_local *local = sdata->local;
++ u64 weight_sum, weight_sum_reciprocal;
++ struct airtime_sched_info *air_sched;
++ struct airtime_info *air_info;
+ u32 airtime = 0;
+
+- if (sta->local->airtime_flags & AIRTIME_USE_TX)
++ air_sched = &local->airtime[txq->ac];
++ air_info = to_airtime_info(txq);
++
++ if (local->airtime_flags & AIRTIME_USE_TX)
+ airtime += tx_airtime;
+- if (sta->local->airtime_flags & AIRTIME_USE_RX)
++ if (local->airtime_flags & AIRTIME_USE_RX)
+ airtime += rx_airtime;
+
+- spin_lock_bh(&local->active_txq_lock[ac]);
+- sta->airtime[ac].tx_airtime += tx_airtime;
+- sta->airtime[ac].rx_airtime += rx_airtime;
+- sta->airtime[ac].deficit -= airtime;
+- spin_unlock_bh(&local->active_txq_lock[ac]);
++ /* Weights scale so the unit weight is 256 */
++ airtime <<= 8;
++
++ spin_lock_bh(&air_sched->lock);
++
++ air_info->tx_airtime += tx_airtime;
++ air_info->rx_airtime += rx_airtime;
++
++ if (air_sched->weight_sum) {
++ weight_sum = air_sched->weight_sum;
++ weight_sum_reciprocal = air_sched->weight_sum_reciprocal;
++ } else {
++ weight_sum = air_info->weight;
++ weight_sum_reciprocal = air_info->weight_reciprocal;
++ }
++
++ /* Round the calculation of global vt */
++ air_sched->v_t += (u64)((airtime + (weight_sum >> 1)) *
++ weight_sum_reciprocal) >> IEEE80211_RECIPROCAL_SHIFT_64;
++ air_info->v_t += (u32)((airtime + (air_info->weight >> 1)) *
++ air_info->weight_reciprocal) >> IEEE80211_RECIPROCAL_SHIFT_32;
++ ieee80211_resort_txq(&local->hw, txq);
++
++ spin_unlock_bh(&air_sched->lock);
++}
++
++void ieee80211_sta_register_airtime(struct ieee80211_sta *pubsta, u8 tid,
++ u32 tx_airtime, u32 rx_airtime)
++{
++ struct ieee80211_txq *txq = pubsta->txq[tid];
++
++ if (!txq)
++ return;
++
++ ieee80211_register_airtime(txq, tx_airtime, rx_airtime);
+ }
+ EXPORT_SYMBOL(ieee80211_sta_register_airtime);
+
+@@ -2354,7 +2385,7 @@ void sta_set_sinfo(struct sta_info *sta,
+ }
+
+ if (!(sinfo->filled & BIT_ULL(NL80211_STA_INFO_AIRTIME_WEIGHT))) {
+- sinfo->airtime_weight = sta->airtime_weight;
++ sinfo->airtime_weight = sta->airtime[0].weight;
+ sinfo->filled |= BIT_ULL(NL80211_STA_INFO_AIRTIME_WEIGHT);
+ }
+
+--- a/net/mac80211/sta_info.h
++++ b/net/mac80211/sta_info.h
+@@ -135,18 +135,25 @@ enum ieee80211_agg_stop_reason {
+ #define AIRTIME_USE_TX BIT(0)
+ #define AIRTIME_USE_RX BIT(1)
+
++
+ struct airtime_info {
+ u64 rx_airtime;
+ u64 tx_airtime;
+- s64 deficit;
++ u64 v_t;
++ u64 last_scheduled;
++ struct list_head list;
+ atomic_t aql_tx_pending; /* Estimated airtime for frames pending */
+ u32 aql_limit_low;
+ u32 aql_limit_high;
++ u32 weight_reciprocal;
++ u16 weight;
+ };
+
+ void ieee80211_sta_update_pending_airtime(struct ieee80211_local *local,
+ struct sta_info *sta, u8 ac,
+ u16 tx_airtime, bool tx_completed);
++void ieee80211_register_airtime(struct ieee80211_txq *txq,
++ u32 tx_airtime, u32 rx_airtime);
+
+ struct sta_info;
+
+@@ -515,7 +522,6 @@ struct ieee80211_fragment_cache {
+ * @tid_seq: per-TID sequence numbers for sending to this STA
+ * @airtime: per-AC struct airtime_info describing airtime statistics for this
+ * station
+- * @airtime_weight: station weight for airtime fairness calculation purposes
+ * @ampdu_mlme: A-MPDU state machine state
+ * @mesh: mesh STA information
+ * @debugfs_dir: debug filesystem directory dentry
+@@ -646,7 +652,6 @@ struct sta_info {
+ u16 tid_seq[IEEE80211_QOS_CTL_TID_MASK + 1];
+
+ struct airtime_info airtime[IEEE80211_NUM_ACS];
+- u16 airtime_weight;
+
+ /*
+ * Aggregation information, locked with lock.
+--- a/net/mac80211/status.c
++++ b/net/mac80211/status.c
+@@ -972,6 +972,25 @@ static void __ieee80211_tx_status(struct
+ if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
+ ieee80211_frame_acked(sta, skb);
+
++ } else if (wiphy_ext_feature_isset(local->hw.wiphy,
++ NL80211_EXT_FEATURE_AIRTIME_FAIRNESS)) {
++ struct ieee80211_sub_if_data *sdata;
++ struct ieee80211_txq *txq;
++ u32 airtime;
++
++ /* Account airtime to multicast queue */
++ sdata = ieee80211_sdata_from_skb(local, skb);
++
++ if (sdata && (txq = sdata->vif.txq)) {
++ airtime = info->status.tx_time ?:
++ ieee80211_calc_expected_tx_airtime(hw,
++ &sdata->vif,
++ NULL,
++ skb->len,
++ false);
++
++ ieee80211_register_airtime(txq, airtime, 0);
++ }
+ }
+
+ /* SNMP counters
+--- a/net/mac80211/tx.c
++++ b/net/mac80211/tx.c
+@@ -18,6 +18,7 @@
+ #include <linux/bitmap.h>
+ #include <linux/rcupdate.h>
+ #include <linux/export.h>
++#include <linux/timekeeping.h>
+ #include <net/net_namespace.h>
+ #include <net/ieee80211_radiotap.h>
+ #include <net/cfg80211.h>
+@@ -1489,7 +1490,7 @@ void ieee80211_txq_init(struct ieee80211
+ codel_vars_init(&txqi->def_cvars);
+ codel_stats_init(&txqi->cstats);
+ __skb_queue_head_init(&txqi->frags);
+- INIT_LIST_HEAD(&txqi->schedule_order);
++ RB_CLEAR_NODE(&txqi->schedule_order);
+
+ txqi->txq.vif = &sdata->vif;
+
+@@ -1533,9 +1534,7 @@ void ieee80211_txq_purge(struct ieee8021
+ ieee80211_purge_tx_queue(&local->hw, &txqi->frags);
+ spin_unlock_bh(&fq->lock);
+
+- spin_lock_bh(&local->active_txq_lock[txqi->txq.ac]);
+- list_del_init(&txqi->schedule_order);
+- spin_unlock_bh(&local->active_txq_lock[txqi->txq.ac]);
++ ieee80211_unschedule_txq(&local->hw, &txqi->txq, true);
+ }
+
+ void ieee80211_txq_set_params(struct ieee80211_local *local)
+@@ -3819,102 +3818,259 @@ EXPORT_SYMBOL(ieee80211_tx_dequeue);
+ struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw, u8 ac)
+ {
+ struct ieee80211_local *local = hw_to_local(hw);
++ struct airtime_sched_info *air_sched;
++ u64 now = ktime_get_boottime_ns();
+ struct ieee80211_txq *ret = NULL;
+- struct txq_info *txqi = NULL, *head = NULL;
+- bool found_eligible_txq = false;
++ struct airtime_info *air_info;
++ struct txq_info *txqi = NULL;
++ struct rb_node *node;
++ bool first = false;
+
+- spin_lock_bh(&local->active_txq_lock[ac]);
++ air_sched = &local->airtime[ac];
++ spin_lock_bh(&air_sched->lock);
+
+- begin:
+- txqi = list_first_entry_or_null(&local->active_txqs[ac],
+- struct txq_info,
+- schedule_order);
+- if (!txqi)
++ node = air_sched->schedule_pos;
++
++begin:
++ if (!node) {
++ node = rb_first_cached(&air_sched->active_txqs);
++ first = true;
++ } else {
++ node = rb_next(node);
++ }
++
++ if (!node)
+ goto out;
+
+- if (txqi == head) {
+- if (!found_eligible_txq)
+- goto out;
+- else
+- found_eligible_txq = false;
++ txqi = container_of(node, struct txq_info, schedule_order);
++ air_info = to_airtime_info(&txqi->txq);
++
++ if (air_info->v_t > air_sched->v_t &&
++ (!first || !airtime_catchup_v_t(air_sched, air_info->v_t, now)))
++ goto out;
++
++ if (!ieee80211_txq_airtime_check(hw, &txqi->txq)) {
++ first = false;
++ goto begin;
+ }
+
+- if (!head)
+- head = txqi;
++ air_sched->schedule_pos = node;
++ air_sched->last_schedule_activity = now;
++ ret = &txqi->txq;
++out:
++ spin_unlock_bh(&air_sched->lock);
++ return ret;
++}
++EXPORT_SYMBOL(ieee80211_next_txq);
+
+- if (txqi->txq.sta) {
+- struct sta_info *sta = container_of(txqi->txq.sta,
+- struct sta_info, sta);
+- bool aql_check = ieee80211_txq_airtime_check(hw, &txqi->txq);
+- s64 deficit = sta->airtime[txqi->txq.ac].deficit;
++static void __ieee80211_insert_txq(struct rb_root_cached *root,
++ struct txq_info *txqi)
++{
++ struct rb_node **new = &root->rb_root.rb_node;
++ struct airtime_info *old_air, *new_air;
++ struct rb_node *parent = NULL;
++ struct txq_info *__txqi;
++ bool leftmost = true;
++
++ while (*new) {
++ parent = *new;
++ __txqi = rb_entry(parent, struct txq_info, schedule_order);
++ old_air = to_airtime_info(&__txqi->txq);
++ new_air = to_airtime_info(&txqi->txq);
+
+- if (aql_check)
+- found_eligible_txq = true;
++ if (new_air->v_t <= old_air->v_t) {
++ new = &parent->rb_left;
++ } else {
++ new = &parent->rb_right;
++ leftmost = false;
++ }
++ }
+
+- if (deficit < 0)
+- sta->airtime[txqi->txq.ac].deficit +=
+- sta->airtime_weight;
+-
+- if (deficit < 0 || !aql_check) {
+- list_move_tail(&txqi->schedule_order,
+- &local->active_txqs[txqi->txq.ac]);
+- goto begin;
++ rb_link_node(&txqi->schedule_order, parent, new);
++ rb_insert_color_cached(&txqi->schedule_order, root, leftmost);
++}
++
++void ieee80211_resort_txq(struct ieee80211_hw *hw,
++ struct ieee80211_txq *txq)
++{
++ struct airtime_info *air_info = to_airtime_info(txq);
++ struct ieee80211_local *local = hw_to_local(hw);
++ struct txq_info *txqi = to_txq_info(txq);
++ struct airtime_sched_info *air_sched;
++
++ air_sched = &local->airtime[txq->ac];
++
++ lockdep_assert_held(&air_sched->lock);
++
++ if (!RB_EMPTY_NODE(&txqi->schedule_order)) {
++ struct airtime_info *a_prev = NULL, *a_next = NULL;
++ struct txq_info *t_prev, *t_next;
++ struct rb_node *n_prev, *n_next;
++
++ /* Erasing a node can cause an expensive rebalancing operation,
++ * so we check the previous and next nodes first and only remove
++ * and re-insert if the current node is not already in the
++ * correct position.
++ */
++ if ((n_prev = rb_prev(&txqi->schedule_order)) != NULL) {
++ t_prev = container_of(n_prev, struct txq_info,
++ schedule_order);
++ a_prev = to_airtime_info(&t_prev->txq);
++ }
++
++ if ((n_next = rb_next(&txqi->schedule_order)) != NULL) {
++ t_next = container_of(n_next, struct txq_info,
++ schedule_order);
++ a_next = to_airtime_info(&t_next->txq);
+ }
++
++ if ((!a_prev || a_prev->v_t <= air_info->v_t) &&
++ (!a_next || a_next->v_t > air_info->v_t))
++ return;
++
++ if (air_sched->schedule_pos == &txqi->schedule_order)
++ air_sched->schedule_pos = n_prev;
++
++ rb_erase_cached(&txqi->schedule_order,
++ &air_sched->active_txqs);
++ RB_CLEAR_NODE(&txqi->schedule_order);
++ __ieee80211_insert_txq(&air_sched->active_txqs, txqi);
+ }
++}
++
++void ieee80211_update_airtime_weight(struct ieee80211_local *local,
++ struct airtime_sched_info *air_sched,
++ u64 now, bool force)
++{
++ struct airtime_info *air_info, *tmp;
++ u64 weight_sum = 0;
++
++ if (unlikely(!now))
++ now = ktime_get_boottime_ns();
++
++ lockdep_assert_held(&air_sched->lock);
++
++ if (!force && (air_sched->last_weight_update <
++ now - AIRTIME_ACTIVE_DURATION))
++ return;
++
++ list_for_each_entry_safe(air_info, tmp,
++ &air_sched->active_list, list) {
++ if (airtime_is_active(air_info, now))
++ weight_sum += air_info->weight;
++ else
++ list_del_init(&air_info->list);
++ }
++ airtime_weight_sum_set(air_sched, weight_sum);
++ air_sched->last_weight_update = now;
++}
+
++void ieee80211_schedule_txq(struct ieee80211_hw *hw,
++ struct ieee80211_txq *txq)
++ __acquires(txq_lock) __releases(txq_lock)
++{
++ struct ieee80211_local *local = hw_to_local(hw);
++ struct txq_info *txqi = to_txq_info(txq);
++ struct airtime_sched_info *air_sched;
++ u64 now = ktime_get_boottime_ns();
++ struct airtime_info *air_info;
++ u8 ac = txq->ac;
++ bool was_active;
+
+- if (txqi->schedule_round == local->schedule_round[ac])
++ air_sched = &local->airtime[ac];
++ air_info = to_airtime_info(txq);
++
++ spin_lock_bh(&air_sched->lock);
++ was_active = airtime_is_active(air_info, now);
++ airtime_set_active(air_sched, air_info, now);
++
++ if (!RB_EMPTY_NODE(&txqi->schedule_order))
+ goto out;
+
+- list_del_init(&txqi->schedule_order);
+- txqi->schedule_round = local->schedule_round[ac];
+- ret = &txqi->txq;
++ /* If the station has been inactive for a while, catch up its v_t so it
++ * doesn't get indefinite priority; see comment above the definition of
++ * AIRTIME_MAX_BEHIND.
++ */
++ if ((!was_active && air_info->v_t < air_sched->v_t) ||
++ air_info->v_t < air_sched->v_t - AIRTIME_MAX_BEHIND)
++ air_info->v_t = air_sched->v_t;
++
++ ieee80211_update_airtime_weight(local, air_sched, now, !was_active);
++ __ieee80211_insert_txq(&air_sched->active_txqs, txqi);
+
+ out:
+- spin_unlock_bh(&local->active_txq_lock[ac]);
+- return ret;
++ spin_unlock_bh(&air_sched->lock);
+ }
+-EXPORT_SYMBOL(ieee80211_next_txq);
++EXPORT_SYMBOL(ieee80211_schedule_txq);
+
+-void __ieee80211_schedule_txq(struct ieee80211_hw *hw,
+- struct ieee80211_txq *txq,
+- bool force)
++static void __ieee80211_unschedule_txq(struct ieee80211_hw *hw,
++ struct ieee80211_txq *txq,
++ bool purge)
+ {
+ struct ieee80211_local *local = hw_to_local(hw);
+ struct txq_info *txqi = to_txq_info(txq);
++ struct airtime_sched_info *air_sched;
++ struct airtime_info *air_info;
+
+- spin_lock_bh(&local->active_txq_lock[txq->ac]);
++ air_sched = &local->airtime[txq->ac];
++ air_info = to_airtime_info(&txqi->txq);
+
+- if (list_empty(&txqi->schedule_order) &&
+- (force || !skb_queue_empty(&txqi->frags) ||
+- txqi->tin.backlog_packets)) {
+- /* If airtime accounting is active, always enqueue STAs at the
+- * head of the list to ensure that they only get moved to the
+- * back by the airtime DRR scheduler once they have a negative
+- * deficit. A station that already has a negative deficit will
+- * get immediately moved to the back of the list on the next
+- * call to ieee80211_next_txq().
+- */
+- if (txqi->txq.sta && local->airtime_flags &&
+- wiphy_ext_feature_isset(local->hw.wiphy,
+- NL80211_EXT_FEATURE_AIRTIME_FAIRNESS))
+- list_add(&txqi->schedule_order,
+- &local->active_txqs[txq->ac]);
+- else
+- list_add_tail(&txqi->schedule_order,
+- &local->active_txqs[txq->ac]);
++ lockdep_assert_held(&air_sched->lock);
++
++ if (purge) {
++ list_del_init(&air_info->list);
++ ieee80211_update_airtime_weight(local, air_sched, 0, true);
+ }
+
+- spin_unlock_bh(&local->active_txq_lock[txq->ac]);
++ if (RB_EMPTY_NODE(&txqi->schedule_order))
++ return;
++
++ if (air_sched->schedule_pos == &txqi->schedule_order)
++ air_sched->schedule_pos = rb_prev(&txqi->schedule_order);
++
++ if (!purge)
++ airtime_set_active(air_sched, air_info,
++ ktime_get_boottime_ns());
++
++ rb_erase_cached(&txqi->schedule_order,
++ &air_sched->active_txqs);
++ RB_CLEAR_NODE(&txqi->schedule_order);
++}
++
++void ieee80211_unschedule_txq(struct ieee80211_hw *hw,
++ struct ieee80211_txq *txq,
++ bool purge)
++ __acquires(txq_lock) __releases(txq_lock)
++{
++ struct ieee80211_local *local = hw_to_local(hw);
++
++ spin_lock_bh(&local->airtime[txq->ac].lock);
++ __ieee80211_unschedule_txq(hw, txq, purge);
++ spin_unlock_bh(&local->airtime[txq->ac].lock);
++}
++
++void ieee80211_return_txq(struct ieee80211_hw *hw,
++ struct ieee80211_txq *txq, bool force)
++{
++ struct ieee80211_local *local = hw_to_local(hw);
++ struct txq_info *txqi = to_txq_info(txq);
++
++ spin_lock_bh(&local->airtime[txq->ac].lock);
++
++ if (!RB_EMPTY_NODE(&txqi->schedule_order) && !force &&
++ !txq_has_queue(txq))
++ __ieee80211_unschedule_txq(hw, txq, false);
++
++ spin_unlock_bh(&local->airtime[txq->ac].lock);
+ }
+-EXPORT_SYMBOL(__ieee80211_schedule_txq);
++EXPORT_SYMBOL(ieee80211_return_txq);
+
+ DEFINE_STATIC_KEY_FALSE(aql_disable);
+
+ bool ieee80211_txq_airtime_check(struct ieee80211_hw *hw,
+ struct ieee80211_txq *txq)
+ {
+- struct sta_info *sta;
++ struct airtime_info *air_info = to_airtime_info(txq);
+ struct ieee80211_local *local = hw_to_local(hw);
+
+ if (!wiphy_ext_feature_isset(local->hw.wiphy, NL80211_EXT_FEATURE_AQL))
+@@ -3929,15 +4085,12 @@ bool ieee80211_txq_airtime_check(struct
+ if (unlikely(txq->tid == IEEE80211_NUM_TIDS))
+ return true;
+
+- sta = container_of(txq->sta, struct sta_info, sta);
+- if (atomic_read(&sta->airtime[txq->ac].aql_tx_pending) <
+- sta->airtime[txq->ac].aql_limit_low)
++ if (atomic_read(&air_info->aql_tx_pending) < air_info->aql_limit_low)
+ return true;
+
+ if (atomic_read(&local->aql_total_pending_airtime) <
+ local->aql_threshold &&
+- atomic_read(&sta->airtime[txq->ac].aql_tx_pending) <
+- sta->airtime[txq->ac].aql_limit_high)
++ atomic_read(&air_info->aql_tx_pending) < air_info->aql_limit_high)
+ return true;
+
+ return false;
+@@ -3947,60 +4100,59 @@ EXPORT_SYMBOL(ieee80211_txq_airtime_chec
+ bool ieee80211_txq_may_transmit(struct ieee80211_hw *hw,
+ struct ieee80211_txq *txq)
+ {
++ struct txq_info *first_txqi = NULL, *txqi = to_txq_info(txq);
+ struct ieee80211_local *local = hw_to_local(hw);
+- struct txq_info *iter, *tmp, *txqi = to_txq_info(txq);
+- struct sta_info *sta;
+- u8 ac = txq->ac;
++ struct airtime_sched_info *air_sched;
++ struct airtime_info *air_info;
++ struct rb_node *node = NULL;
++ bool ret = false;
++ u64 now;
+
+- spin_lock_bh(&local->active_txq_lock[ac]);
+
+- if (!txqi->txq.sta)
+- goto out;
++ if (!ieee80211_txq_airtime_check(hw, txq))
++ return false;
++
++ air_sched = &local->airtime[txq->ac];
++ spin_lock_bh(&air_sched->lock);
+
+- if (list_empty(&txqi->schedule_order))
++ if (RB_EMPTY_NODE(&txqi->schedule_order))
+ goto out;
+
+- list_for_each_entry_safe(iter, tmp, &local->active_txqs[ac],
+- schedule_order) {
+- if (iter == txqi)
+- break;
++ now = ktime_get_boottime_ns();
+
+- if (!iter->txq.sta) {
+- list_move_tail(&iter->schedule_order,
+- &local->active_txqs[ac]);
+- continue;
+- }
+- sta = container_of(iter->txq.sta, struct sta_info, sta);
+- if (sta->airtime[ac].deficit < 0)
+- sta->airtime[ac].deficit += sta->airtime_weight;
+- list_move_tail(&iter->schedule_order, &local->active_txqs[ac]);
++ /* Like in ieee80211_next_txq(), make sure the first station in the
++ * scheduling order is eligible for transmission to avoid starvation.
++ */
++ node = rb_first_cached(&air_sched->active_txqs);
++ if (node) {
++ first_txqi = container_of(node, struct txq_info,
++ schedule_order);
++ air_info = to_airtime_info(&first_txqi->txq);
++
++ if (air_sched->v_t < air_info->v_t)
++ airtime_catchup_v_t(air_sched, air_info->v_t, now);
+ }
+
+- sta = container_of(txqi->txq.sta, struct sta_info, sta);
+- if (sta->airtime[ac].deficit >= 0)
+- goto out;
+-
+- sta->airtime[ac].deficit += sta->airtime_weight;
+- list_move_tail(&txqi->schedule_order, &local->active_txqs[ac]);
+- spin_unlock_bh(&local->active_txq_lock[ac]);
++ air_info = to_airtime_info(&txqi->txq);
++ if (air_info->v_t <= air_sched->v_t) {
++ air_sched->last_schedule_activity = now;
++ ret = true;
++ }
+
+- return false;
+ out:
+- if (!list_empty(&txqi->schedule_order))
+- list_del_init(&txqi->schedule_order);
+- spin_unlock_bh(&local->active_txq_lock[ac]);
+-
+- return true;
++ spin_unlock_bh(&air_sched->lock);
++ return ret;
+ }
+ EXPORT_SYMBOL(ieee80211_txq_may_transmit);
+
+ void ieee80211_txq_schedule_start(struct ieee80211_hw *hw, u8 ac)
+ {
+ struct ieee80211_local *local = hw_to_local(hw);
++ struct airtime_sched_info *air_sched = &local->airtime[ac];
+
+- spin_lock_bh(&local->active_txq_lock[ac]);
+- local->schedule_round[ac]++;
+- spin_unlock_bh(&local->active_txq_lock[ac]);
++ spin_lock_bh(&air_sched->lock);
++ air_sched->schedule_pos = NULL;
++ spin_unlock_bh(&air_sched->lock);
+ }
+ EXPORT_SYMBOL(ieee80211_txq_schedule_start);
+
projects / openwrt / staging / pepe2k.git / commitdiff