mac80211: move A-MPDU session check from minstrel_ht to mac80211

This avoids calling back into tx handlers from within the rate control module.
Preparation for deferring rate control until tx dequeue
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20210617163113.75815-1-nbd@nbd.nameSigned-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -6184,6 +6184,11 @@ enum rate_control_capabilities {
 	 * otherwise the NSS difference doesn't bother us.
 	 */
 	RATE_CTRL_CAPA_VHT_EXT_NSS_BW = BIT(0),
+	/**
+	 * @RATE_CTRL_CAPA_AMPDU_TRIGGER:
+	 * mac80211 should start A-MPDU sessions on tx
+	 */
+	RATE_CTRL_CAPA_AMPDU_TRIGGER = BIT(1),
 };
 
 struct rate_control_ops {

net/mac80211/rc80211_minstrel_ht.c

@@ -1175,29 +1175,6 @@ minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
 	}
 }
 
-static void
-minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
-{
-	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
-	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
-	u16 tid;
-
-	if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
-		return;
-
-	if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
-		return;
-
-	if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
-		return;
-
-	tid = ieee80211_get_tid(hdr);
-	if (likely(sta->ampdu_mlme.tid_tx[tid]))
-		return;
-
-	ieee80211_start_tx_ba_session(pubsta, tid, 0);
-}
-
 static void
 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
                       void *priv_sta, struct ieee80211_tx_status *st)
@@ -1502,10 +1479,6 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
 	struct minstrel_priv *mp = priv;
 	u16 sample_idx;
 
-	if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
-	    !minstrel_ht_is_legacy_group(MI_RATE_GROUP(mi->max_prob_rate)))
-		minstrel_aggr_check(sta, txrc->skb);
-
 	info->flags |= mi->tx_flags;
 
 #ifdef CONFIG_MAC80211_DEBUGFS
@@ -1911,6 +1884,7 @@ static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
 
 static const struct rate_control_ops mac80211_minstrel_ht = {
 	.name = "minstrel_ht",
+	.capa = RATE_CTRL_CAPA_AMPDU_TRIGGER,
 	.tx_status_ext = minstrel_ht_tx_status,
 	.get_rate = minstrel_ht_get_rate,
 	.rate_init = minstrel_ht_rate_init,

net/mac80211/tx.c

@@ -3949,6 +3949,29 @@ void ieee80211_txq_schedule_start(struct ieee80211_hw *hw, u8 ac)
 }
 EXPORT_SYMBOL(ieee80211_txq_schedule_start);
 
+static void
+ieee80211_aggr_check(struct ieee80211_sub_if_data *sdata,
+		     struct sta_info *sta,
+		     struct sk_buff *skb)
+{
+	struct rate_control_ref *ref = sdata->local->rate_ctrl;
+	u16 tid;
+
+	if (!ref || !(ref->ops->capa & RATE_CTRL_CAPA_AMPDU_TRIGGER))
+		return;
+
+	if (!sta || !sta->sta.ht_cap.ht_supported ||
+	    !sta->sta.wme || skb_get_queue_mapping(skb) == IEEE80211_AC_VO ||
+	    skb->protocol == sdata->control_port_protocol)
+		return;
+
+	tid = skb->priority & IEEE80211_QOS_CTL_TID_MASK;
+	if (likely(sta->ampdu_mlme.tid_tx[tid]))
+		return;
+
+	ieee80211_start_tx_ba_session(&sta->sta, tid, 0);
+}
+
 void __ieee80211_subif_start_xmit(struct sk_buff *skb,
 				  struct net_device *dev,
 				  u32 info_flags,
@@ -3979,6 +4002,8 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
 		skb_get_hash(skb);
 	}
 
+	ieee80211_aggr_check(sdata, sta, skb);
+
 	if (sta) {
 		struct ieee80211_fast_tx *fast_tx;
 
@@ -4242,6 +4267,8 @@ static void ieee80211_8023_xmit(struct ieee80211_sub_if_data *sdata,
 
 	memset(info, 0, sizeof(*info));
 
+	ieee80211_aggr_check(sdata, sta, skb);
+
 	tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
 	if (tid_tx) {