package/kernel/mac80211/patches/subsys/330-mac80211-add-AQL-support-for-broadcast-packets.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Fri, 9 Feb 2024 19:43:40 +0100
   3 Subject: [PATCH] mac80211: add AQL support for broadcast packets
   4
   5 Excessive broadcast traffic with little competing unicast traffic can easily
   6 flood hardware queues, leading to throughput issues. Additionally, filling
   7 the hardware queues with too many packets breaks FQ for broadcast data.
   8 Fix this by enabling AQL for broadcast packets.
   9
  10 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  11 ---
  12
  13 --- a/include/net/cfg80211.h
  14 +++ b/include/net/cfg80211.h
  15 @@ -3324,6 +3324,7 @@ enum wiphy_params_flags {
  16  /* The per TXQ device queue limit in airtime */
  17  #define IEEE80211_DEFAULT_AQL_TXQ_LIMIT_L      5000
  18  #define IEEE80211_DEFAULT_AQL_TXQ_LIMIT_H      12000
  19 +#define IEEE80211_DEFAULT_AQL_TXQ_LIMIT_BC     50000
  20
  21  /* The per interface airtime threshold to switch to lower queue limit */
  22  #define IEEE80211_AQL_THRESHOLD                        24000
  23 --- a/net/mac80211/debugfs.c
  24 +++ b/net/mac80211/debugfs.c
  25 @@ -215,11 +215,13 @@ static ssize_t aql_pending_read(struct f
  26                         "VI     %u us\n"
  27                         "BE     %u us\n"
  28                         "BK     %u us\n"
  29 +                       "BC/MC  %u us\n"
  30                         "total  %u us\n",
  31                         atomic_read(&local->aql_ac_pending_airtime[IEEE80211_AC_VO]),
  32                         atomic_read(&local->aql_ac_pending_airtime[IEEE80211_AC_VI]),
  33                         atomic_read(&local->aql_ac_pending_airtime[IEEE80211_AC_BE]),
  34                         atomic_read(&local->aql_ac_pending_airtime[IEEE80211_AC_BK]),
  35 +                       atomic_read(&local->aql_bc_pending_airtime),
  36                         atomic_read(&local->aql_total_pending_airtime));
  37         return simple_read_from_buffer(user_buf, count, ppos,
  38                                        buf, len);
  39 @@ -245,7 +247,8 @@ static ssize_t aql_txq_limit_read(struct
  40                         "VO     %u              %u\n"
  41                         "VI     %u              %u\n"
  42                         "BE     %u              %u\n"
  43 -                       "BK     %u              %u\n",
  44 +                       "BK     %u              %u\n"
  45 +                       "BC/MC  %u\n",
  46                         local->aql_txq_limit_low[IEEE80211_AC_VO],
  47                         local->aql_txq_limit_high[IEEE80211_AC_VO],
  48                         local->aql_txq_limit_low[IEEE80211_AC_VI],
  49 @@ -253,7 +256,8 @@ static ssize_t aql_txq_limit_read(struct
  50                         local->aql_txq_limit_low[IEEE80211_AC_BE],
  51                         local->aql_txq_limit_high[IEEE80211_AC_BE],
  52                         local->aql_txq_limit_low[IEEE80211_AC_BK],
  53 -                       local->aql_txq_limit_high[IEEE80211_AC_BK]);
  54 +                       local->aql_txq_limit_high[IEEE80211_AC_BK],
  55 +                       local->aql_txq_limit_bc);
  56         return simple_read_from_buffer(user_buf, count, ppos,
  57                                        buf, len);
  58  }
  59 @@ -279,6 +283,11 @@ static ssize_t aql_txq_limit_write(struc
  60         else
  61                 buf[count] = '\0';
  62
  63 +       if (sscanf(buf, "mcast %u", &q_limit_low) == 1) {
  64 +               local->aql_txq_limit_bc = q_limit_low;
  65 +               return count;
  66 +       }
  67 +
  68         if (sscanf(buf, "%u %u %u", &ac, &q_limit_low, &q_limit_high) != 3)
  69                 return -EINVAL;
  70
  71 --- a/net/mac80211/ieee80211_i.h
  72 +++ b/net/mac80211/ieee80211_i.h
  73 @@ -1328,10 +1328,12 @@ struct ieee80211_local {
  74         spinlock_t handle_wake_tx_queue_lock;
  75
  76         u16 airtime_flags;
  77 +       u32 aql_txq_limit_bc;
  78         u32 aql_txq_limit_low[IEEE80211_NUM_ACS];
  79         u32 aql_txq_limit_high[IEEE80211_NUM_ACS];
  80         u32 aql_threshold;
  81         atomic_t aql_total_pending_airtime;
  82 +       atomic_t aql_bc_pending_airtime;
  83         atomic_t aql_ac_pending_airtime[IEEE80211_NUM_ACS];
  84
  85         const struct ieee80211_ops *ops;
  86 --- a/net/mac80211/main.c
  87 +++ b/net/mac80211/main.c
  88 @@ -788,6 +788,7 @@ struct ieee80211_hw *ieee80211_alloc_hw_
  89         spin_lock_init(&local->rx_path_lock);
  90         spin_lock_init(&local->queue_stop_reason_lock);
  91
  92 +       local->aql_txq_limit_bc = IEEE80211_DEFAULT_AQL_TXQ_LIMIT_BC;
  93         for (i = 0; i < IEEE80211_NUM_ACS; i++) {
  94                 INIT_LIST_HEAD(&local->active_txqs[i]);
  95                 spin_lock_init(&local->active_txq_lock[i]);
  96 --- a/net/mac80211/sta_info.c
  97 +++ b/net/mac80211/sta_info.c
  98 @@ -2343,13 +2343,28 @@ EXPORT_SYMBOL(ieee80211_sta_recalc_aggre
  99
 100  void ieee80211_sta_update_pending_airtime(struct ieee80211_local *local,
 101                                           struct sta_info *sta, u8 ac,
 102 -                                         u16 tx_airtime, bool tx_completed)
 103 +                                         u16 tx_airtime, bool tx_completed,
 104 +                                         bool mcast)
 105  {
 106         int tx_pending;
 107
 108         if (!wiphy_ext_feature_isset(local->hw.wiphy, NL80211_EXT_FEATURE_AQL))
 109                 return;
 110
 111 +       if (mcast) {
 112 +               if (!tx_completed) {
 113 +                       atomic_add(tx_airtime, &local->aql_bc_pending_airtime);
 114 +                       return;
 115 +               }
 116 +
 117 +               tx_pending = atomic_sub_return(tx_airtime,
 118 +                                              &local->aql_bc_pending_airtime);
 119 +               if (tx_pending < 0)
 120 +                       atomic_cmpxchg(&local->aql_bc_pending_airtime,
 121 +                                      tx_pending, 0);
 122 +               return;
 123 +       }
 124 +
 125         if (!tx_completed) {
 126                 if (sta)
 127                         atomic_add(tx_airtime,
 128 --- a/net/mac80211/tx.c
 129 +++ b/net/mac80211/tx.c
 130 @@ -2536,7 +2536,7 @@ static u16 ieee80211_store_ack_skb(struc
 131
 132                 spin_lock_irqsave(&local->ack_status_lock, flags);
 133                 id = idr_alloc(&local->ack_status_frames, ack_skb,
 134 -                              1, 0x2000, GFP_ATOMIC);
 135 +                              1, 0x1000, GFP_ATOMIC);
 136                 spin_unlock_irqrestore(&local->ack_status_lock, flags);
 137
 138                 if (id >= 0) {
 139 @@ -3958,20 +3958,20 @@ begin:
 140  encap_out:
 141         IEEE80211_SKB_CB(skb)->control.vif = vif;
 142
 143 -       if (tx.sta &&
 144 -           wiphy_ext_feature_isset(local->hw.wiphy, NL80211_EXT_FEATURE_AQL)) {
 145 -               bool ampdu = txq->ac != IEEE80211_AC_VO;
 146 +       if (wiphy_ext_feature_isset(local->hw.wiphy, NL80211_EXT_FEATURE_AQL)) {
 147 +               bool ampdu = txq->sta && txq->ac != IEEE80211_AC_VO;
 148                 u32 airtime;
 149
 150                 airtime = ieee80211_calc_expected_tx_airtime(hw, vif, txq->sta,
 151                                                              skb->len, ampdu);
 152 -               if (airtime) {
 153 -                       airtime = ieee80211_info_set_tx_time_est(info, airtime);
 154 -                       ieee80211_sta_update_pending_airtime(local, tx.sta,
 155 -                                                            txq->ac,
 156 -                                                            airtime,
 157 -                                                            false);
 158 -               }
 159 +               if (!airtime)
 160 +                       return skb;
 161 +
 162 +               airtime = ieee80211_info_set_tx_time_est(info, airtime);
 163 +               info->tx_time_mc = !tx.sta;
 164 +               ieee80211_sta_update_pending_airtime(local, tx.sta, txq->ac,
 165 +                                                    airtime, false,
 166 +                                                    info->tx_time_mc);
 167         }
 168
 169         return skb;
 170 @@ -4026,6 +4026,7 @@ struct ieee80211_txq *ieee80211_next_txq
 171         struct ieee80211_txq *ret = NULL;
 172         struct txq_info *txqi = NULL, *head = NULL;
 173         bool found_eligible_txq = false;
 174 +       bool aql_check;
 175
 176         spin_lock_bh(&local->active_txq_lock[ac]);
 177
 178 @@ -4049,26 +4050,26 @@ struct ieee80211_txq *ieee80211_next_txq
 179         if (!head)
 180                 head = txqi;
 181
 182 +       aql_check = ieee80211_txq_airtime_check(hw, &txqi->txq);
 183 +       if (aql_check)
 184 +               found_eligible_txq = true;
 185 +
 186         if (txqi->txq.sta) {
 187                 struct sta_info *sta = container_of(txqi->txq.sta,
 188                                                     struct sta_info, sta);
 189 -               bool aql_check = ieee80211_txq_airtime_check(hw, &txqi->txq);
 190 -               s32 deficit = ieee80211_sta_deficit(sta, txqi->txq.ac);
 191 -
 192 -               if (aql_check)
 193 -                       found_eligible_txq = true;
 194 -
 195 -               if (deficit < 0)
 196 +               if (ieee80211_sta_deficit(sta, txqi->txq.ac) < 0) {
 197                         sta->airtime[txqi->txq.ac].deficit +=
 198                                 sta->airtime_weight << AIRTIME_QUANTUM_SHIFT;
 199 -
 200 -               if (deficit < 0 || !aql_check) {
 201 -                       list_move_tail(&txqi->schedule_order,
 202 -                                      &local->active_txqs[txqi->txq.ac]);
 203 -                       goto begin;
 204 +                       aql_check = false;
 205                 }
 206         }
 207
 208 +       if (!aql_check) {
 209 +               list_move_tail(&txqi->schedule_order,
 210 +                                  &local->active_txqs[txqi->txq.ac]);
 211 +               goto begin;
 212 +       }
 213 +
 214         if (txqi->schedule_round == local->schedule_round[ac])
 215                 goto out;
 216
 217 @@ -4133,7 +4134,8 @@ bool ieee80211_txq_airtime_check(struct
 218                 return true;
 219
 220         if (!txq->sta)
 221 -               return true;
 222 +               return atomic_read(&local->aql_bc_pending_airtime) <
 223 +                      local->aql_txq_limit_bc;
 224
 225         if (unlikely(txq->tid == IEEE80211_NUM_TIDS))
 226                 return true;
 227 @@ -4182,15 +4184,15 @@ bool ieee80211_txq_may_transmit(struct i
 228
 229         spin_lock_bh(&local->active_txq_lock[ac]);
 230
 231 -       if (!txqi->txq.sta)
 232 -               goto out;
 233 -
 234         if (list_empty(&txqi->schedule_order))
 235                 goto out;
 236
 237         if (!ieee80211_txq_schedule_airtime_check(local, ac))
 238                 goto out;
 239
 240 +       if (!txqi->txq.sta)
 241 +               goto out;
 242 +
 243         list_for_each_entry_safe(iter, tmp, &local->active_txqs[ac],
 244                                  schedule_order) {
 245                 if (iter == txqi)
 246 --- a/include/net/mac80211.h
 247 +++ b/include/net/mac80211.h
 248 @@ -1116,6 +1116,7 @@ ieee80211_rate_get_vht_nss(const struct
 249   *     link the frame will be transmitted on
 250   * @hw_queue: HW queue to put the frame on, skb_get_queue_mapping() gives the AC
 251   * @ack_frame_id: internal frame ID for TX status, used internally
 252 + * @tx_time_mc: TX time is for a multicast packet
 253   * @tx_time_est: TX time estimate in units of 4us, used internally
 254   * @control: union part for control data
 255   * @control.rates: TX rates array to try
 256 @@ -1155,8 +1156,9 @@ struct ieee80211_tx_info {
 257         /* common information */
 258         u32 flags;
 259         u32 band:3,
 260 -           ack_frame_id:13,
 261 +           ack_frame_id:12,
 262             hw_queue:4,
 263 +           tx_time_mc:1,
 264             tx_time_est:10;
 265         /* 2 free bits */
 266
 267 --- a/net/mac80211/sta_info.h
 268 +++ b/net/mac80211/sta_info.h
 269 @@ -147,7 +147,8 @@ struct airtime_info {
 270
 271  void ieee80211_sta_update_pending_airtime(struct ieee80211_local *local,
 272                                           struct sta_info *sta, u8 ac,
 273 -                                         u16 tx_airtime, bool tx_completed);
 274 +                                         u16 tx_airtime, bool tx_completed,
 275 +                                         bool mcast);
 276
 277  struct sta_info;
 278
 279 --- a/net/mac80211/status.c
 280 +++ b/net/mac80211/status.c
 281 @@ -716,7 +716,7 @@ static void ieee80211_report_used_skb(st
 282                 ieee80211_sta_update_pending_airtime(local, sta,
 283                                                      skb_get_queue_mapping(skb),
 284                                                      tx_time_est,
 285 -                                                    true);
 286 +                                                    true, info->tx_time_mc);
 287                 rcu_read_unlock();
 288         }
 289
 290 @@ -1127,10 +1127,11 @@ void ieee80211_tx_status_ext(struct ieee
 291                 /* Do this here to avoid the expensive lookup of the sta
 292                  * in ieee80211_report_used_skb().
 293                  */
 294 +               bool mcast = IEEE80211_SKB_CB(skb)->tx_time_mc;
 295                 ieee80211_sta_update_pending_airtime(local, sta,
 296                                                      skb_get_queue_mapping(skb),
 297                                                      tx_time_est,
 298 -                                                    true);
 299 +                                                    true, mcast);
 300                 ieee80211_info_set_tx_time_est(IEEE80211_SKB_CB(skb), 0);
 301         }
 302