From: Alexander Wetzel Date: Sun, 9 Oct 2022 18:30:38 +0200 Subject: [PATCH] wifi: mac80211: add internal handler for wake_tx_queue Start to align the TX handling to only use internal TX queues (iTXQs): Provide a handler for drivers not having a custom wake_tx_queue callback and update the documentation. Signed-off-by: Alexander Wetzel Signed-off-by: Johannes Berg --- --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -89,15 +89,13 @@ /** * DOC: mac80211 software tx queueing * - * mac80211 provides an optional intermediate queueing implementation designed - * to allow the driver to keep hardware queues short and provide some fairness - * between different stations/interfaces. - * In this model, the driver pulls data frames from the mac80211 queue instead - * of letting mac80211 push them via drv_tx(). - * Other frames (e.g. control or management) are still pushed using drv_tx(). + * mac80211 uses an intermediate queueing implementation, designed to allow the + * driver to keep hardware queues short and to provide some fairness between + * different stations/interfaces. * - * Drivers indicate that they use this model by implementing the .wake_tx_queue - * driver operation. + * Drivers must provide the .wake_tx_queue driver operation by either + * linking it to ieee80211_handle_wake_tx_queue() or implementing a custom + * handler. * * Intermediate queues (struct ieee80211_txq) are kept per-sta per-tid, with * another per-sta for non-data/non-mgmt and bufferable management frames, and @@ -106,9 +104,12 @@ * The driver is expected to initialize its private per-queue data for stations * and interfaces in the .add_interface and .sta_add ops. * - * The driver can't access the queue directly. To dequeue a frame from a - * txq, it calls ieee80211_tx_dequeue(). Whenever mac80211 adds a new frame to a - * queue, it calls the .wake_tx_queue driver op. + * The driver can't access the internal TX queues (iTXQs) directly. + * Whenever mac80211 adds a new frame to a queue, it calls the .wake_tx_queue + * driver op. + * Drivers implementing a custom .wake_tx_queue op can get them by calling + * ieee80211_tx_dequeue(). Drivers using ieee80211_handle_wake_tx_queue() will + * simply get the individual frames pushed via the .tx driver operation. * * Drivers can optionally delegate responsibility for scheduling queues to * mac80211, to take advantage of airtime fairness accounting. In this case, to @@ -1826,7 +1827,7 @@ struct ieee80211_vif_cfg { * for this interface. * @drv_priv: data area for driver use, will always be aligned to * sizeof(void \*). - * @txq: the multicast data TX queue (if driver uses the TXQ abstraction) + * @txq: the multicast data TX queue * @txqs_stopped: per AC flag to indicate that intermediate TXQs are stopped, * protected by fq->lock. * @offload_flags: 802.3 -> 802.11 enapsulation offload flags, see @@ -2252,8 +2253,8 @@ struct ieee80211_link_sta { * For non MLO STA it will point to the deflink data. For MLO STA * ieee80211_sta_recalc_aggregates() must be called to update it. * @support_p2p_ps: indicates whether the STA supports P2P PS mechanism or not. - * @txq: per-TID data TX queues (if driver uses the TXQ abstraction); note that - * the last entry (%IEEE80211_NUM_TIDS) is used for non-data frames + * @txq: per-TID data TX queues; note that the last entry (%IEEE80211_NUM_TIDS) + * is used for non-data frames * @deflink: This holds the default link STA information, for non MLO STA all link * specific STA information is accessed through @deflink or through * link[0] which points to address of @deflink. For MLO Link STA @@ -5691,7 +5692,7 @@ void ieee80211_key_replay(struct ieee802 * @hw: pointer as obtained from ieee80211_alloc_hw(). * @queue: queue number (counted from zero). * - * Drivers should use this function instead of netif_wake_queue. + * Drivers must use this function instead of netif_wake_queue. */ void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue); @@ -5700,7 +5701,7 @@ void ieee80211_wake_queue(struct ieee802 * @hw: pointer as obtained from ieee80211_alloc_hw(). * @queue: queue number (counted from zero). * - * Drivers should use this function instead of netif_stop_queue. + * Drivers must use this function instead of netif_stop_queue. */ void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue); @@ -5709,7 +5710,7 @@ void ieee80211_stop_queue(struct ieee802 * @hw: pointer as obtained from ieee80211_alloc_hw(). * @queue: queue number (counted from zero). * - * Drivers should use this function instead of netif_stop_queue. + * Drivers must use this function instead of netif_queue_stopped. * * Return: %true if the queue is stopped. %false otherwise. */ @@ -5720,7 +5721,7 @@ int ieee80211_queue_stopped(struct ieee8 * ieee80211_stop_queues - stop all queues * @hw: pointer as obtained from ieee80211_alloc_hw(). * - * Drivers should use this function instead of netif_stop_queue. + * Drivers must use this function instead of netif_tx_stop_all_queues. */ void ieee80211_stop_queues(struct ieee80211_hw *hw); @@ -5728,7 +5729,7 @@ void ieee80211_stop_queues(struct ieee80 * ieee80211_wake_queues - wake all queues * @hw: pointer as obtained from ieee80211_alloc_hw(). * - * Drivers should use this function instead of netif_wake_queue. + * Drivers must use this function instead of netif_tx_wake_all_queues. */ void ieee80211_wake_queues(struct ieee80211_hw *hw); @@ -6950,6 +6951,18 @@ static inline struct sk_buff *ieee80211_ } /** + * ieee80211_handle_wake_tx_queue - mac80211 handler for wake_tx_queue callback + * + * @hw: pointer as obtained from wake_tx_queue() callback(). + * @txq: pointer as obtained from wake_tx_queue() callback(). + * + * Drivers can use this function for the mandatory mac80211 wake_tx_queue + * callback in struct ieee80211_ops. They should not call this function. + */ +void ieee80211_handle_wake_tx_queue(struct ieee80211_hw *hw, + struct ieee80211_txq *txq); + +/** * ieee80211_next_txq - get next tx queue to pull packets from * * @hw: pointer as obtained from ieee80211_alloc_hw() --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -288,6 +288,52 @@ __le16 ieee80211_ctstoself_duration(stru } EXPORT_SYMBOL(ieee80211_ctstoself_duration); +static void wake_tx_push_queue(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata, + struct ieee80211_txq *queue) +{ + int q = sdata->vif.hw_queue[queue->ac]; + struct ieee80211_tx_control control = { + .sta = queue->sta, + }; + struct sk_buff *skb; + unsigned long flags; + bool q_stopped; + + while (1) { + spin_lock_irqsave(&local->queue_stop_reason_lock, flags); + q_stopped = local->queue_stop_reasons[q]; + spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); + + if (q_stopped) + break; + + skb = ieee80211_tx_dequeue(&local->hw, queue); + if (!skb) + break; + + drv_tx(local, &control, skb); + } +} + +/* wake_tx_queue handler for driver not implementing a custom one*/ +void ieee80211_handle_wake_tx_queue(struct ieee80211_hw *hw, + struct ieee80211_txq *txq) +{ + struct ieee80211_local *local = hw_to_local(hw); + struct ieee80211_sub_if_data *sdata = vif_to_sdata(txq->vif); + struct ieee80211_txq *queue; + + /* Use ieee80211_next_txq() for airtime fairness accounting */ + ieee80211_txq_schedule_start(hw, txq->ac); + while ((queue = ieee80211_next_txq(hw, txq->ac))) { + wake_tx_push_queue(local, sdata, queue); + ieee80211_return_txq(hw, queue, false); + } + ieee80211_txq_schedule_end(hw, txq->ac); +} +EXPORT_SYMBOL(ieee80211_handle_wake_tx_queue); + static void __ieee80211_wake_txqs(struct ieee80211_sub_if_data *sdata, int ac) { struct ieee80211_local *local = sdata->local;