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.

A side effect is that these counters, available via debugfs, become now invalid:

* dot11TransmittedFragmentCount
* dot11FrameDuplicateCount,
* dot11ReceivedFragmentCount
* dot11MulticastReceivedFrameCount

Signed-off-by: Felix Fietkau <nbd@nbd.name>
[kvalo@qca.qualcomm.com: add a note about counters, thanks to Zefir Kurtisi]
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 8ddd604..b99ffa0 100644 (file)
--- 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, struct ath_txq *txq)
 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_softc *sc, struct ath_txq *txq)
        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,
@@ -253,7 +272,7 @@ static void ath_tx_flush_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
                }
 
                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) {
@@ -318,12 +337,12 @@ static void ath_tid_drain(struct ath_softc *sc, struct ath_txq *txq,
                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);
        }
 }
 
@@ -426,12 +445,11 @@ static void ath_tx_count_frames(struct ath_softc *sc, struct ath_buf *bf,
 
 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;
@@ -460,12 +478,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
        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;
@@ -473,7 +486,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
                        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;
                }
@@ -583,7 +596,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
                                                                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) {
@@ -604,7 +617,8 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
                                        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;
@@ -648,8 +662,6 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
                ath_txq_lock(sc, txq);
        }
 
-       rcu_read_unlock();
-
        if (needreset)
                ath9k_queue_reset(sc, RESET_TYPE_TX_ERROR);
 }
@@ -664,7 +676,10 @@ static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,
                                  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);
@@ -677,6 +692,10 @@ static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,
 
        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);
@@ -685,9 +704,9 @@ static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,
                        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);
@@ -923,7 +942,7 @@ ath_tx_get_tid_subframe(struct ath_softc *sc, struct ath_txq *txq,
                        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;
                }
 
@@ -1832,6 +1851,7 @@ static void ath_drain_txq_list(struct ath_softc *sc, struct ath_txq *txq,
  */
 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) {
@@ -1850,6 +1870,7 @@ void ath_draintxq(struct ath_softc *sc, struct ath_txq *txq)
        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)
@@ -2472,7 +2493,8 @@ void ath_tx_cabq(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 /*****************/
 
 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);
@@ -2492,15 +2514,17 @@ static void ath_tx_complete(struct ath_softc *sc, struct sk_buff *skb,
                        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);
@@ -2515,12 +2539,14 @@ static void ath_tx_complete(struct ath_softc *sc, struct sk_buff *skb,
        }
        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;
@@ -2548,7 +2574,7 @@ static void ath_tx_complete_buf(struct ath_softc *sc, struct ath_buf *bf,
                        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
@@ -2700,10 +2726,12 @@ 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)
@@ -2717,6 +2745,7 @@ void ath_tx_edma_tasklet(struct ath_softc *sc)
        struct list_head *fifo_list;
        int status;
 
+       rcu_read_lock();
        for (;;) {
                if (test_bit(ATH_OP_HW_RESET, &common->op_flags))
                        break;
@@ -2787,6 +2816,7 @@ void ath_tx_edma_tasklet(struct ath_softc *sc)
                ath_tx_process_buffer(sc, txq, &ts, bf, &bf_head);
                ath_txq_unlock_complete(sc, txq);
        }
+       rcu_read_unlock();
 }
 
 /*****************/