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 d961f11201e..eb4cdefda62 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 fbec5f7eca6..727e8de22fd 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 ac393a6dbe7..34005e11502 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;