ath9k: clean up the aggregation tid queue

Use a sk_buff_head instead containing skbs instead of a list_head
containing ath_bufs. This makes it easier to decouple the aggregation
code from the ath_buf struct

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 45 insertions, 37 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index d961f11201e9..eb4cdefda629 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -206,6 +206,7 @@ struct ath_atx_ac {
 };
 
 struct ath_frame_info {
+        struct ath_buf *bf;
         int framelen;
         enum ath9k_key_type keytype;
         u8 keyix;
@@ -235,7 +236,7 @@ struct ath_buf {
 
 struct ath_atx_tid {
         struct list_head list;
-        struct list_head buf_q;
+        struct sk_buff_head buf_q;
         struct ath_node *an;
         struct ath_atx_ac *ac;
         unsigned long tx_buf[BITS_TO_LONGS(ATH_TID_MAX_BUFS)];
diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c
index fbec5f7eca6e..727e8de22fda 100644
--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -711,7 +711,7 @@ static ssize_t read_file_stations(struct file *file, char __user *user_buf,
                                         " tid: %p %s %s %i %p %p\n",
                                         tid, tid->sched ? "sched" : "idle",
                                         tid->paused ? "paused" : "running",
-                                        list_empty(&tid->buf_q),
+                                        skb_queue_empty(&tid->buf_q),
                                         tid->an, tid->ac);
                         if (len >= size)
                                 goto done;
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index ac393a6dbe77..34005e11502c 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -129,7 +129,7 @@ static void ath_tx_resume_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
         spin_lock_bh(&txq->axq_lock);
         tid->paused = false;
 
-        if (list_empty(&tid->buf_q))
+        if (skb_queue_empty(&tid->buf_q))
                 goto unlock;
 
         ath_tx_queue_tid(txq, tid);
@@ -149,6 +149,7 @@ static struct ath_frame_info *get_frame_info(struct sk_buff *skb)
 static void ath_tx_flush_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
 {
         struct ath_txq *txq = tid->ac->txq;
+        struct sk_buff *skb;
         struct ath_buf *bf;
         struct list_head bf_head;
         struct ath_tx_status ts;
@@ -159,12 +160,13 @@ static void ath_tx_flush_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
         memset(&ts, 0, sizeof(ts));
         spin_lock_bh(&txq->axq_lock);
 
-        while (!list_empty(&tid->buf_q)) {
-                bf = list_first_entry(&tid->buf_q, struct ath_buf, list);
-                list_move_tail(&bf->list, &bf_head);
+        while ((skb = __skb_dequeue(&tid->buf_q))) {
+                fi = get_frame_info(skb);
+                bf = fi->bf;
+
+                list_add_tail(&bf->list, &bf_head);
 
                 spin_unlock_bh(&txq->axq_lock);
-                fi = get_frame_info(bf->bf_mpdu);
                 if (fi->retries) {
                         ath_tx_update_baw(sc, tid, fi->seqno);
                         ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0, 1);
@@ -219,6 +221,7 @@ static void ath_tid_drain(struct ath_softc *sc, struct ath_txq *txq,
                           struct ath_atx_tid *tid)
 
 {
+        struct sk_buff *skb;
         struct ath_buf *bf;
         struct list_head bf_head;
         struct ath_tx_status ts;
@@ -227,14 +230,12 @@ static void ath_tid_drain(struct ath_softc *sc, struct ath_txq *txq,
         memset(&ts, 0, sizeof(ts));
         INIT_LIST_HEAD(&bf_head);
 
-        for (;;) {
-                if (list_empty(&tid->buf_q))
-                        break;
+        while ((skb = __skb_dequeue(&tid->buf_q))) {
+                fi = get_frame_info(skb);
+                bf = fi->bf;
 
-                bf = list_first_entry(&tid->buf_q, struct ath_buf, list);
-                list_move_tail(&bf->list, &bf_head);
+                list_add_tail(&bf->list, &bf_head);
 
-                fi = get_frame_info(bf->bf_mpdu);
                 if (fi->retries)
                         ath_tx_update_baw(sc, tid, fi->seqno);
 
@@ -349,7 +350,8 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
         struct ieee80211_tx_info *tx_info;
         struct ath_atx_tid *tid = NULL;
         struct ath_buf *bf_next, *bf_last = bf->bf_lastbf;
-        struct list_head bf_head, bf_pending;
+        struct list_head bf_head;
+        struct sk_buff_head bf_pending;
         u16 seq_st = 0, acked_cnt = 0, txfail_cnt = 0;
         u32 ba[WME_BA_BMP_SIZE >> 5];
         int isaggr, txfail, txpending, sendbar = 0, needreset = 0, nbad = 0;
@@ -422,8 +424,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
                 }
         }
 
-        INIT_LIST_HEAD(&bf_pending);
-        INIT_LIST_HEAD(&bf_head);
+        __skb_queue_head_init(&bf_pending);
 
         ath_tx_count_frames(sc, bf, ts, txok, &nframes, &nbad);
         while (bf) {
@@ -467,10 +468,10 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
                  * Make sure the last desc is reclaimed if it
                  * not a holding desc.
                  */
-                if (!bf_last->bf_stale || bf_next != NULL)
+                INIT_LIST_HEAD(&bf_head);
+                if ((sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) ||
+                    bf_next != NULL || !bf_last->bf_stale)
                         list_move_tail(&bf->list, &bf_head);
-                else
-                        INIT_LIST_HEAD(&bf_head);
 
                 if (!txpending || (tid->state & AGGR_CLEANUP)) {
                         /*
@@ -521,7 +522,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
 
                                         ath9k_hw_cleartxdesc(sc->sc_ah,
                                                              tbf->bf_desc);
-                                        list_add_tail(&tbf->list, &bf_head);
+                                        fi->bf = tbf;
                                 } else {
                                         /*
                                          * Clear descriptor status words for
@@ -536,21 +537,21 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
                          * Put this buffer to the temporary pending
                          * queue to retain ordering
                          */
-                        list_splice_tail_init(&bf_head, &bf_pending);
+                        __skb_queue_tail(&bf_pending, skb);
                 }
 
                 bf = bf_next;
         }
 
         /* prepend un-acked frames to the beginning of the pending frame queue */
-        if (!list_empty(&bf_pending)) {
+        if (!skb_queue_empty(&bf_pending)) {
                 if (an->sleeping)
                         ieee80211_sta_set_tim(sta);
 
                 spin_lock_bh(&txq->axq_lock);
                 if (clear_filter)
                         tid->ac->clear_ps_filter = true;
-                list_splice(&bf_pending, &tid->buf_q);
+                skb_queue_splice(&bf_pending, &tid->buf_q);
                 if (!an->sleeping)
                         ath_tx_queue_tid(txq, tid);
                 spin_unlock_bh(&txq->axq_lock);
@@ -743,19 +744,22 @@ static enum ATH_AGGR_STATUS ath_tx_form_aggr(struct ath_softc *sc,
                                              int *aggr_len)
 {
 #define PADBYTES(_len) ((4 - ((_len) % 4)) % 4)
-        struct ath_buf *bf, *bf_first, *bf_prev = NULL;
+        struct ath_buf *bf, *bf_first = NULL, *bf_prev = NULL;
         int rl = 0, nframes = 0, ndelim, prev_al = 0;
         u16 aggr_limit = 0, al = 0, bpad = 0,
                 al_delta, h_baw = tid->baw_size / 2;
         enum ATH_AGGR_STATUS status = ATH_AGGR_DONE;
         struct ieee80211_tx_info *tx_info;
         struct ath_frame_info *fi;
-
-        bf_first = list_first_entry(&tid->buf_q, struct ath_buf, list);
+        struct sk_buff *skb;
 
         do {
-                bf = list_first_entry(&tid->buf_q, struct ath_buf, list);
-                fi = get_frame_info(bf->bf_mpdu);
+                skb = skb_peek(&tid->buf_q);
+                fi = get_frame_info(skb);
+                bf = fi->bf;
+
+                if (!bf_first)
+                        bf_first = bf;
 
                 /* do not step over block-ack window */
                 if (!BAW_WITHIN(tid->seq_start, tid->baw_size, fi->seqno)) {
@@ -808,7 +812,9 @@ static enum ATH_AGGR_STATUS ath_tx_form_aggr(struct ath_softc *sc,
                 if (!fi->retries)
                         ath_tx_addto_baw(sc, tid, fi->seqno);
                 ath9k_hw_set11n_aggr_middle(sc->sc_ah, bf->bf_desc, ndelim);
-                list_move_tail(&bf->list, bf_q);
+
+                __skb_unlink(skb, &tid->buf_q);
+                list_add_tail(&bf->list, bf_q);
                 if (bf_prev) {
                         bf_prev->bf_next = bf;
                         ath9k_hw_set_desc_link(sc->sc_ah, bf_prev->bf_desc,
@@ -816,7 +822,7 @@ static enum ATH_AGGR_STATUS ath_tx_form_aggr(struct ath_softc *sc,
                 }
                 bf_prev = bf;
 
-        } while (!list_empty(&tid->buf_q));
+        } while (!skb_queue_empty(&tid->buf_q));
 
         *aggr_len = al;
 
@@ -834,7 +840,7 @@ static void ath_tx_sched_aggr(struct ath_softc *sc, struct ath_txq *txq,
         int aggr_len;
 
         do {
-                if (list_empty(&tid->buf_q))
+                if (skb_queue_empty(&tid->buf_q))
                         return;
 
                 INIT_LIST_HEAD(&bf_q);
@@ -955,7 +961,7 @@ bool ath_tx_aggr_sleep(struct ath_softc *sc, struct ath_node *an)
 
                 spin_lock_bh(&txq->axq_lock);
 
-                if (!list_empty(&tid->buf_q))
+                if (!skb_queue_empty(&tid->buf_q))
                         buffered = true;
 
                 tid->sched = false;
@@ -988,7 +994,7 @@ void ath_tx_aggr_wakeup(struct ath_softc *sc, struct ath_node *an)
                 spin_lock_bh(&txq->axq_lock);
                 ac->clear_ps_filter = true;
 
-                if (!list_empty(&tid->buf_q) && !tid->paused) {
+                if (!skb_queue_empty(&tid->buf_q) && !tid->paused) {
                         ath_tx_queue_tid(txq, tid);
                         ath_txq_schedule(sc, txq);
                 }
@@ -1332,7 +1338,7 @@ void ath_txq_schedule(struct ath_softc *sc, struct ath_txq *txq)
                          * add tid to round-robin queue if more frames
                          * are pending for the tid
                          */
-                        if (!list_empty(&tid->buf_q))
+                        if (!skb_queue_empty(&tid->buf_q))
                                 ath_tx_queue_tid(txq, tid);
 
                         if (tid == last_tid ||
@@ -1438,7 +1444,7 @@ static void ath_tx_send_ampdu(struct ath_softc *sc, struct ath_atx_tid *tid,
          * - seqno is not within block-ack window
          * - h/w queue depth exceeds low water mark
          */
-        if (!list_empty(&tid->buf_q) || tid->paused ||
+        if (!skb_queue_empty(&tid->buf_q) || tid->paused ||
             !BAW_WITHIN(tid->seq_start, tid->baw_size, fi->seqno) ||
             txctl->txq->axq_ampdu_depth >= ATH_AGGR_MIN_QDEPTH) {
                 /*
@@ -1446,7 +1452,7 @@ static void ath_tx_send_ampdu(struct ath_softc *sc, struct ath_atx_tid *tid,
                  * for aggregation.
                  */
                 TX_STAT_INC(txctl->txq->axq_qnum, a_queued_sw);
-                list_add_tail(&bf->list, &tid->buf_q);
+                __skb_queue_tail(&tid->buf_q, bf->bf_mpdu);
                 if (!txctl->an || !txctl->an->sleeping)
                         ath_tx_queue_tid(txctl->txq, tid);
                 return;
@@ -1777,6 +1783,7 @@ static struct ath_buf *ath_tx_setup_buffer(struct ieee80211_hw *hw,
                             bf->bf_buf_addr,
                             txq->axq_qnum);
 
+        fi->bf = bf;
 
         return bf;
 }
@@ -2394,7 +2401,7 @@ void ath_tx_node_init(struct ath_softc *sc, struct ath_node *an)
                 tid->sched     = false;
                 tid->paused    = false;
                 tid->state &= ~AGGR_CLEANUP;
-                INIT_LIST_HEAD(&tid->buf_q);
+                __skb_queue_head_init(&tid->buf_q);
                 acno = TID_TO_WME_AC(tidno);
                 tid->ac = &an->ac[acno];
                 tid->state &= ~AGGR_ADDBA_COMPLETE;