mac80211: add an intermediate software queue implementation

This allows drivers to request per-vif and per-sta-tid queues from which
they can pull frames. This makes it easier to keep the hardware queues
short, and to improve fairness between clients and vifs.

The task of scheduling packet transmission is left up to the driver -
queueing is controlled by mac80211. Drivers can only dequeue packets by
calling ieee80211_tx_dequeue. This makes it possible to add active queue
management later without changing drivers using this code.

This can also be used as a starting point to implement A-MSDU
aggregation in a way that does not add artificially induced latency.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
[resolved minor context conflict, minor changes, endian annotations]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 3c1512b0442c..04b32f3e0395 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -811,6 +811,19 @@ struct mac80211_qos_map {
 	struct rcu_head rcu_head;
 };
 
+enum txq_info_flags {
+	IEEE80211_TXQ_STOP,
+	IEEE80211_TXQ_AMPDU,
+};
+
+struct txq_info {
+	struct sk_buff_head queue;
+	unsigned long flags;
+
+	/* keep last! */
+	struct ieee80211_txq txq;
+};
+
 struct ieee80211_sub_if_data {
 	struct list_head list;
 
@@ -853,6 +866,7 @@ struct ieee80211_sub_if_data {
 	bool control_port_no_encrypt;
 	int encrypt_headroom;
 
+	atomic_t txqs_len[IEEE80211_NUM_ACS];
 	struct ieee80211_tx_queue_params tx_conf[IEEE80211_NUM_ACS];
 	struct mac80211_qos_map __rcu *qos_map;
 
@@ -1450,6 +1464,10 @@ static inline struct ieee80211_local *hw_to_local(
 	return container_of(hw, struct ieee80211_local, hw);
 }
 
+static inline struct txq_info *to_txq_info(struct ieee80211_txq *txq)
+{
+	return container_of(txq, struct txq_info, txq);
+}
 
 static inline int ieee80211_bssid_match(const u8 *raddr, const u8 *addr)
 {
@@ -1906,6 +1924,9 @@ static inline bool ieee80211_can_run_worker(struct ieee80211_local *local)
 	return true;
 }
 
+void ieee80211_init_tx_queue(struct ieee80211_sub_if_data *sdata,
+			     struct sta_info *sta,
+			     struct txq_info *txq, int tid);
 void ieee80211_send_auth(struct ieee80211_sub_if_data *sdata,
 			 u16 transaction, u16 auth_alg, u16 status,
 			 const u8 *extra, size_t extra_len, const u8 *bssid,