ath9k: improve performance in tx status handling

Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 305 insertions, 0 deletions

diff --git a/package/kernel/mac80211/patches/335-ath9k-use-ieee80211_tx_status_noskb-where-possible.patch b/package/kernel/mac80211/patches/335-ath9k-use-ieee80211_tx_status_noskb-where-possible.patch
new file mode 100644
index 0000000..dbb5b90
--- /dev/null
+++ b/package/kernel/mac80211/patches/335-ath9k-use-ieee80211_tx_status_noskb-where-possible.patch
@@ -0,0 +1,305 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Tue, 2 Aug 2016 12:12:18 +0200
+Subject: [PATCH] ath9k: use ieee80211_tx_status_noskb where possible
+
+It removes the need for undoing the padding changes to skb->data and it
+improves performance by eliminating one tx status lookup per MPDU in the
+status path. It is also useful for preparing a follow-up fix to better
+handle powersave filtering.
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+
+--- a/drivers/net/wireless/ath/ath9k/xmit.c
++++ b/drivers/net/wireless/ath/ath9k/xmit.c
+@@ -50,9 +50,11 @@ static u16 bits_per_symbol[][2] = {
+ static void ath_tx_send_normal(struct ath_softc *sc, struct ath_txq *txq,
+ 			       struct ath_atx_tid *tid, struct sk_buff *skb);
+ static void ath_tx_complete(struct ath_softc *sc, struct sk_buff *skb,
+-			    int tx_flags, struct ath_txq *txq);
++			    int tx_flags, struct ath_txq *txq,
++			    struct ieee80211_sta *sta);
+ static void ath_tx_complete_buf(struct ath_softc *sc, struct ath_buf *bf,
+ 				struct ath_txq *txq, struct list_head *bf_q,
++				struct ieee80211_sta *sta,
+ 				struct ath_tx_status *ts, int txok);
+ static void ath_tx_txqaddbuf(struct ath_softc *sc, struct ath_txq *txq,
+ 			     struct list_head *head, bool internal);
+@@ -77,6 +79,22 @@ enum {
+ /* Aggregation logic */
+ /*********************/
+ 
++static void ath_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
++{
++	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
++	struct ieee80211_sta *sta = info->status.status_driver_data[0];
++
++	if (info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS) {
++		ieee80211_tx_status(hw, skb);
++		return;
++	}
++
++	if (sta)
++		ieee80211_tx_status_noskb(hw, sta, info);
++
++	dev_kfree_skb(skb);
++}
++
+ void ath_txq_lock(struct ath_softc *sc, struct ath_txq *txq)
+ 	__acquires(&txq->axq_lock)
+ {
+@@ -92,6 +110,7 @@ void ath_txq_unlock(struct ath_softc *sc
+ void ath_txq_unlock_complete(struct ath_softc *sc, struct ath_txq *txq)
+ 	__releases(&txq->axq_lock)
+ {
++	struct ieee80211_hw *hw = sc->hw;
+ 	struct sk_buff_head q;
+ 	struct sk_buff *skb;
+ 
+@@ -100,7 +119,7 @@ void ath_txq_unlock_complete(struct ath_
+ 	spin_unlock_bh(&txq->axq_lock);
+ 
+ 	while ((skb = __skb_dequeue(&q)))
+-		ieee80211_tx_status(sc->hw, skb);
++		ath_tx_status(hw, skb);
+ }
+ 
+ static void ath_tx_queue_tid(struct ath_softc *sc, struct ath_txq *txq,
+@@ -268,7 +287,7 @@ static void ath_tx_flush_tid(struct ath_
+ 		}
+ 
+ 		list_add_tail(&bf->list, &bf_head);
+-		ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0);
++		ath_tx_complete_buf(sc, bf, txq, &bf_head, NULL, &ts, 0);
+ 	}
+ 
+ 	if (sendbar) {
+@@ -333,12 +352,12 @@ static void ath_tid_drain(struct ath_sof
+ 		bf = fi->bf;
+ 
+ 		if (!bf) {
+-			ath_tx_complete(sc, skb, ATH_TX_ERROR, txq);
++			ath_tx_complete(sc, skb, ATH_TX_ERROR, txq, NULL);
+ 			continue;
+ 		}
+ 
+ 		list_add_tail(&bf->list, &bf_head);
+-		ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0);
++		ath_tx_complete_buf(sc, bf, txq, &bf_head, NULL, &ts, 0);
+ 	}
+ }
+ 
+@@ -441,12 +460,11 @@ static void ath_tx_count_frames(struct a
+ 
+ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
+ 				 struct ath_buf *bf, struct list_head *bf_q,
++				 struct ieee80211_sta *sta,
+ 				 struct ath_tx_status *ts, int txok)
+ {
+ 	struct ath_node *an = NULL;
+ 	struct sk_buff *skb;
+-	struct ieee80211_sta *sta;
+-	struct ieee80211_hw *hw = sc->hw;
+ 	struct ieee80211_hdr *hdr;
+ 	struct ieee80211_tx_info *tx_info;
+ 	struct ath_atx_tid *tid = NULL;
+@@ -475,12 +493,7 @@ static void ath_tx_complete_aggr(struct
+ 	for (i = 0; i < ts->ts_rateindex; i++)
+ 		retries += rates[i].count;
+ 
+-	rcu_read_lock();
+-
+-	sta = ieee80211_find_sta_by_ifaddr(hw, hdr->addr1, hdr->addr2);
+ 	if (!sta) {
+-		rcu_read_unlock();
+-
+ 		INIT_LIST_HEAD(&bf_head);
+ 		while (bf) {
+ 			bf_next = bf->bf_next;
+@@ -488,7 +501,7 @@ static void ath_tx_complete_aggr(struct
+ 			if (!bf->bf_state.stale || bf_next != NULL)
+ 				list_move_tail(&bf->list, &bf_head);
+ 
+-			ath_tx_complete_buf(sc, bf, txq, &bf_head, ts, 0);
++			ath_tx_complete_buf(sc, bf, txq, &bf_head, NULL, ts, 0);
+ 
+ 			bf = bf_next;
+ 		}
+@@ -598,7 +611,7 @@ static void ath_tx_complete_aggr(struct
+ 								ts);
+ 			}
+ 
+-			ath_tx_complete_buf(sc, bf, txq, &bf_head, ts,
++			ath_tx_complete_buf(sc, bf, txq, &bf_head, sta, ts,
+ 				!txfail);
+ 		} else {
+ 			if (tx_info->flags & IEEE80211_TX_STATUS_EOSP) {
+@@ -619,7 +632,8 @@ static void ath_tx_complete_aggr(struct
+ 					ath_tx_update_baw(sc, tid, seqno);
+ 
+ 					ath_tx_complete_buf(sc, bf, txq,
+-							    &bf_head, ts, 0);
++							    &bf_head, NULL, ts,
++							    0);
+ 					bar_index = max_t(int, bar_index,
+ 						ATH_BA_INDEX(seq_first, seqno));
+ 					break;
+@@ -663,8 +677,6 @@ static void ath_tx_complete_aggr(struct
+ 		ath_txq_lock(sc, txq);
+ 	}
+ 
+-	rcu_read_unlock();
+-
+ 	if (needreset)
+ 		ath9k_queue_reset(sc, RESET_TYPE_TX_ERROR);
+ }
+@@ -679,7 +691,10 @@ static void ath_tx_process_buffer(struct
+ 				  struct ath_tx_status *ts, struct ath_buf *bf,
+ 				  struct list_head *bf_head)
+ {
++	struct ieee80211_hw *hw = sc->hw;
+ 	struct ieee80211_tx_info *info;
++	struct ieee80211_sta *sta;
++	struct ieee80211_hdr *hdr;
+ 	bool txok, flush;
+ 
+ 	txok = !(ts->ts_status & ATH9K_TXERR_MASK);
+@@ -692,6 +707,10 @@ static void ath_tx_process_buffer(struct
+ 
+ 	ts->duration = ath9k_hw_get_duration(sc->sc_ah, bf->bf_desc,
+ 					     ts->ts_rateindex);
++
++	hdr = (struct ieee80211_hdr *) bf->bf_mpdu->data;
++	sta = ieee80211_find_sta_by_ifaddr(hw, hdr->addr1, hdr->addr2);
++
+ 	if (!bf_isampdu(bf)) {
+ 		if (!flush) {
+ 			info = IEEE80211_SKB_CB(bf->bf_mpdu);
+@@ -700,9 +719,9 @@ static void ath_tx_process_buffer(struct
+ 			ath_tx_rc_status(sc, bf, ts, 1, txok ? 0 : 1, txok);
+ 			ath_dynack_sample_tx_ts(sc->sc_ah, bf->bf_mpdu, ts);
+ 		}
+-		ath_tx_complete_buf(sc, bf, txq, bf_head, ts, txok);
++		ath_tx_complete_buf(sc, bf, txq, bf_head, sta, ts, txok);
+ 	} else
+-		ath_tx_complete_aggr(sc, txq, bf, bf_head, ts, txok);
++		ath_tx_complete_aggr(sc, txq, bf, bf_head, sta, ts, txok);
+ 
+ 	if (!flush)
+ 		ath_txq_schedule(sc, txq);
+@@ -938,7 +957,7 @@ ath_tx_get_tid_subframe(struct ath_softc
+ 			list_add(&bf->list, &bf_head);
+ 			__skb_unlink(skb, *q);
+ 			ath_tx_update_baw(sc, tid, seqno);
+-			ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0);
++			ath_tx_complete_buf(sc, bf, txq, &bf_head, NULL, &ts, 0);
+ 			continue;
+ 		}
+ 
+@@ -1847,6 +1866,7 @@ static void ath_drain_txq_list(struct at
+  */
+ void ath_draintxq(struct ath_softc *sc, struct ath_txq *txq)
+ {
++	rcu_read_lock();
+ 	ath_txq_lock(sc, txq);
+ 
+ 	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
+@@ -1865,6 +1885,7 @@ void ath_draintxq(struct ath_softc *sc,
+ 	ath_drain_txq_list(sc, txq, &txq->axq_q);
+ 
+ 	ath_txq_unlock_complete(sc, txq);
++	rcu_read_unlock();
+ }
+ 
+ bool ath_drain_all_txq(struct ath_softc *sc)
+@@ -2487,7 +2508,8 @@ void ath_tx_cabq(struct ieee80211_hw *hw
+ /*****************/
+ 
+ static void ath_tx_complete(struct ath_softc *sc, struct sk_buff *skb,
+-			    int tx_flags, struct ath_txq *txq)
++			    int tx_flags, struct ath_txq *txq,
++			    struct ieee80211_sta *sta)
+ {
+ 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
+ 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+@@ -2507,15 +2529,17 @@ static void ath_tx_complete(struct ath_s
+ 			tx_info->flags |= IEEE80211_TX_STAT_ACK;
+ 	}
+ 
+-	padpos = ieee80211_hdrlen(hdr->frame_control);
+-	padsize = padpos & 3;
+-	if (padsize && skb->len>padpos+padsize) {
+-		/*
+-		 * Remove MAC header padding before giving the frame back to
+-		 * mac80211.
+-		 */
+-		memmove(skb->data + padsize, skb->data, padpos);
+-		skb_pull(skb, padsize);
++	if (tx_info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS) {
++		padpos = ieee80211_hdrlen(hdr->frame_control);
++		padsize = padpos & 3;
++		if (padsize && skb->len>padpos+padsize) {
++			/*
++			 * Remove MAC header padding before giving the frame back to
++			 * mac80211.
++			 */
++			memmove(skb->data + padsize, skb->data, padpos);
++			skb_pull(skb, padsize);
++		}
+ 	}
+ 
+ 	spin_lock_irqsave(&sc->sc_pm_lock, flags);
+@@ -2530,12 +2554,14 @@ static void ath_tx_complete(struct ath_s
+ 	}
+ 	spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
+ 
+-	__skb_queue_tail(&txq->complete_q, skb);
+ 	ath_txq_skb_done(sc, txq, skb);
++	tx_info->status.status_driver_data[0] = sta;
++	__skb_queue_tail(&txq->complete_q, skb);
+ }
+ 
+ static void ath_tx_complete_buf(struct ath_softc *sc, struct ath_buf *bf,
+ 				struct ath_txq *txq, struct list_head *bf_q,
++				struct ieee80211_sta *sta,
+ 				struct ath_tx_status *ts, int txok)
+ {
+ 	struct sk_buff *skb = bf->bf_mpdu;
+@@ -2563,7 +2589,7 @@ static void ath_tx_complete_buf(struct a
+ 			complete(&sc->paprd_complete);
+ 	} else {
+ 		ath_debug_stat_tx(sc, bf, ts, txq, tx_flags);
+-		ath_tx_complete(sc, skb, tx_flags, txq);
++		ath_tx_complete(sc, skb, tx_flags, txq, sta);
+ 	}
+ skip_tx_complete:
+ 	/* At this point, skb (bf->bf_mpdu) is consumed...make sure we don't
+@@ -2715,10 +2741,12 @@ void ath_tx_tasklet(struct ath_softc *sc
+ 	u32 qcumask = ((1 << ATH9K_NUM_TX_QUEUES) - 1) & ah->intr_txqs;
+ 	int i;
+ 
++	rcu_read_lock();
+ 	for (i = 0; i < ATH9K_NUM_TX_QUEUES; i++) {
+ 		if (ATH_TXQ_SETUP(sc, i) && (qcumask & (1 << i)))
+ 			ath_tx_processq(sc, &sc->tx.txq[i]);
+ 	}
++	rcu_read_unlock();
+ }
+ 
+ void ath_tx_edma_tasklet(struct ath_softc *sc)
+@@ -2732,6 +2760,7 @@ void ath_tx_edma_tasklet(struct ath_soft
+ 	struct list_head *fifo_list;
+ 	int status;
+ 
++	rcu_read_lock();
+ 	for (;;) {
+ 		if (test_bit(ATH_OP_HW_RESET, &common->op_flags))
+ 			break;
+@@ -2802,6 +2831,7 @@ void ath_tx_edma_tasklet(struct ath_soft
+ 		ath_tx_process_buffer(sc, txq, &ts, bf, &bf_head);
+ 		ath_txq_unlock_complete(sc, txq);
+ 	}
++	rcu_read_unlock();
+ }
+ 
+ /*****************/