package/kernel/mac80211/patches/subsys/306-01-v6.2-wifi-mac80211-add-internal-handler-for-wake_tx_queue.patch

   1 From: Alexander Wetzel <alexander@wetzel-home.de>
   2 Date: Sun, 9 Oct 2022 18:30:38 +0200
   3 Subject: [PATCH] wifi: mac80211: add internal handler for wake_tx_queue
   4
   5 Start to align the TX handling to only use internal TX queues (iTXQs):
   6
   7 Provide a handler for drivers not having a custom wake_tx_queue
   8 callback and update the documentation.
   9
  10 Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
  11 Signed-off-by: Johannes Berg <johannes.berg@intel.com>
  12 ---
  13
  14 --- a/include/net/mac80211.h
  15 +++ b/include/net/mac80211.h
  16 @@ -89,15 +89,13 @@
  17  /**
  18   * DOC: mac80211 software tx queueing
  19   *
  20 - * mac80211 provides an optional intermediate queueing implementation designed
  21 - * to allow the driver to keep hardware queues short and provide some fairness
  22 - * between different stations/interfaces.
  23 - * In this model, the driver pulls data frames from the mac80211 queue instead
  24 - * of letting mac80211 push them via drv_tx().
  25 - * Other frames (e.g. control or management) are still pushed using drv_tx().
  26 + * mac80211 uses an intermediate queueing implementation, designed to allow the
  27 + * driver to keep hardware queues short and to provide some fairness between
  28 + * different stations/interfaces.
  29   *
  30 - * Drivers indicate that they use this model by implementing the .wake_tx_queue
  31 - * driver operation.
  32 + * Drivers must provide the .wake_tx_queue driver operation by either
  33 + * linking it to ieee80211_handle_wake_tx_queue() or implementing a custom
  34 + * handler.
  35   *
  36   * Intermediate queues (struct ieee80211_txq) are kept per-sta per-tid, with
  37   * another per-sta for non-data/non-mgmt and bufferable management frames, and
  38 @@ -106,9 +104,12 @@
  39   * The driver is expected to initialize its private per-queue data for stations
  40   * and interfaces in the .add_interface and .sta_add ops.
  41   *
  42 - * The driver can't access the queue directly. To dequeue a frame from a
  43 - * txq, it calls ieee80211_tx_dequeue(). Whenever mac80211 adds a new frame to a
  44 - * queue, it calls the .wake_tx_queue driver op.
  45 + * The driver can't access the internal TX queues (iTXQs) directly.
  46 + * Whenever mac80211 adds a new frame to a queue, it calls the .wake_tx_queue
  47 + * driver op.
  48 + * Drivers implementing a custom .wake_tx_queue op can get them by calling
  49 + * ieee80211_tx_dequeue(). Drivers using ieee80211_handle_wake_tx_queue() will
  50 + * simply get the individual frames pushed via the .tx driver operation.
  51   *
  52   * Drivers can optionally delegate responsibility for scheduling queues to
  53   * mac80211, to take advantage of airtime fairness accounting. In this case, to
  54 @@ -1826,7 +1827,7 @@ struct ieee80211_vif_cfg {
  55   *     for this interface.
  56   * @drv_priv: data area for driver use, will always be aligned to
  57   *     sizeof(void \*).
  58 - * @txq: the multicast data TX queue (if driver uses the TXQ abstraction)
  59 + * @txq: the multicast data TX queue
  60   * @txqs_stopped: per AC flag to indicate that intermediate TXQs are stopped,
  61   *     protected by fq->lock.
  62   * @offload_flags: 802.3 -> 802.11 enapsulation offload flags, see
  63 @@ -2252,8 +2253,8 @@ struct ieee80211_link_sta {
  64   *     For non MLO STA it will point to the deflink data. For MLO STA
  65   *     ieee80211_sta_recalc_aggregates() must be called to update it.
  66   * @support_p2p_ps: indicates whether the STA supports P2P PS mechanism or not.
  67 - * @txq: per-TID data TX queues (if driver uses the TXQ abstraction); note that
  68 - *     the last entry (%IEEE80211_NUM_TIDS) is used for non-data frames
  69 + * @txq: per-TID data TX queues; note that the last entry (%IEEE80211_NUM_TIDS)
  70 + *     is used for non-data frames
  71   * @deflink: This holds the default link STA information, for non MLO STA all link
  72   *     specific STA information is accessed through @deflink or through
  73   *     link[0] which points to address of @deflink. For MLO Link STA
  74 @@ -5691,7 +5692,7 @@ void ieee80211_key_replay(struct ieee802
  75   * @hw: pointer as obtained from ieee80211_alloc_hw().
  76   * @queue: queue number (counted from zero).
  77   *
  78 - * Drivers should use this function instead of netif_wake_queue.
  79 + * Drivers must use this function instead of netif_wake_queue.
  80   */
  81  void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue);
  82
  83 @@ -5700,7 +5701,7 @@ void ieee80211_wake_queue(struct ieee802
  84   * @hw: pointer as obtained from ieee80211_alloc_hw().
  85   * @queue: queue number (counted from zero).
  86   *
  87 - * Drivers should use this function instead of netif_stop_queue.
  88 + * Drivers must use this function instead of netif_stop_queue.
  89   */
  90  void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue);
  91
  92 @@ -5709,7 +5710,7 @@ void ieee80211_stop_queue(struct ieee802
  93   * @hw: pointer as obtained from ieee80211_alloc_hw().
  94   * @queue: queue number (counted from zero).
  95   *
  96 - * Drivers should use this function instead of netif_stop_queue.
  97 + * Drivers must use this function instead of netif_queue_stopped.
  98   *
  99   * Return: %true if the queue is stopped. %false otherwise.
 100   */
 101 @@ -5720,7 +5721,7 @@ int ieee80211_queue_stopped(struct ieee8
 102   * ieee80211_stop_queues - stop all queues
 103   * @hw: pointer as obtained from ieee80211_alloc_hw().
 104   *
 105 - * Drivers should use this function instead of netif_stop_queue.
 106 + * Drivers must use this function instead of netif_tx_stop_all_queues.
 107   */
 108  void ieee80211_stop_queues(struct ieee80211_hw *hw);
 109
 110 @@ -5728,7 +5729,7 @@ void ieee80211_stop_queues(struct ieee80
 111   * ieee80211_wake_queues - wake all queues
 112   * @hw: pointer as obtained from ieee80211_alloc_hw().
 113   *
 114 - * Drivers should use this function instead of netif_wake_queue.
 115 + * Drivers must use this function instead of netif_tx_wake_all_queues.
 116   */
 117  void ieee80211_wake_queues(struct ieee80211_hw *hw);
 118
 119 @@ -6950,6 +6951,18 @@ static inline struct sk_buff *ieee80211_
 120  }
 121
 122  /**
 123 + * ieee80211_handle_wake_tx_queue - mac80211 handler for wake_tx_queue callback
 124 + *
 125 + * @hw: pointer as obtained from wake_tx_queue() callback().
 126 + * @txq: pointer as obtained from wake_tx_queue() callback().
 127 + *
 128 + * Drivers can use this function for the mandatory mac80211 wake_tx_queue
 129 + * callback in struct ieee80211_ops. They should not call this function.
 130 + */
 131 +void ieee80211_handle_wake_tx_queue(struct ieee80211_hw *hw,
 132 +                                   struct ieee80211_txq *txq);
 133 +
 134 +/**
 135   * ieee80211_next_txq - get next tx queue to pull packets from
 136   *
 137   * @hw: pointer as obtained from ieee80211_alloc_hw()
 138 --- a/net/mac80211/util.c
 139 +++ b/net/mac80211/util.c
 140 @@ -288,6 +288,52 @@ __le16 ieee80211_ctstoself_duration(stru
 141  }
 142  EXPORT_SYMBOL(ieee80211_ctstoself_duration);
 143
 144 +static void wake_tx_push_queue(struct ieee80211_local *local,
 145 +                              struct ieee80211_sub_if_data *sdata,
 146 +                              struct ieee80211_txq *queue)
 147 +{
 148 +       int q = sdata->vif.hw_queue[queue->ac];
 149 +       struct ieee80211_tx_control control = {
 150 +               .sta = queue->sta,
 151 +       };
 152 +       struct sk_buff *skb;
 153 +       unsigned long flags;
 154 +       bool q_stopped;
 155 +
 156 +       while (1) {
 157 +               spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 158 +               q_stopped = local->queue_stop_reasons[q];
 159 +               spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 160 +
 161 +               if (q_stopped)
 162 +                       break;
 163 +
 164 +               skb = ieee80211_tx_dequeue(&local->hw, queue);
 165 +               if (!skb)
 166 +                       break;
 167 +
 168 +               drv_tx(local, &control, skb);
 169 +       }
 170 +}
 171 +
 172 +/* wake_tx_queue handler for driver not implementing a custom one*/
 173 +void ieee80211_handle_wake_tx_queue(struct ieee80211_hw *hw,
 174 +                                   struct ieee80211_txq *txq)
 175 +{
 176 +       struct ieee80211_local *local = hw_to_local(hw);
 177 +       struct ieee80211_sub_if_data *sdata = vif_to_sdata(txq->vif);
 178 +       struct ieee80211_txq *queue;
 179 +
 180 +       /* Use ieee80211_next_txq() for airtime fairness accounting */
 181 +       ieee80211_txq_schedule_start(hw, txq->ac);
 182 +       while ((queue = ieee80211_next_txq(hw, txq->ac))) {
 183 +               wake_tx_push_queue(local, sdata, queue);
 184 +               ieee80211_return_txq(hw, queue, false);
 185 +       }
 186 +       ieee80211_txq_schedule_end(hw, txq->ac);
 187 +}
 188 +EXPORT_SYMBOL(ieee80211_handle_wake_tx_queue);
 189 +
 190  static void __ieee80211_wake_txqs(struct ieee80211_sub_if_data *sdata, int ac)
 191  {
 192         struct ieee80211_local *local = sdata->local;