ath9k_htc: Add TX slots

Maintain a bitmap of slots for transmission and update
the cookie field for every packet with the slot value.
This value would be used for matching packets when TX
completion processing is added.
Signed-off-by: Sujith Manoharan <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/htc.h

@@ -271,6 +271,7 @@ struct ath9k_htc_tx {
 	u8 flags;
 	int queued_cnt;
 	struct sk_buff_head tx_queue;
+	DECLARE_BITMAP(tx_slot, MAX_TX_BUF_NUM);
 	spinlock_t tx_lock;
 };
 
@@ -532,7 +533,7 @@ void ath9k_htc_stop_ani(struct ath9k_htc_priv *priv);
 int ath9k_tx_init(struct ath9k_htc_priv *priv);
 void ath9k_tx_tasklet(unsigned long data);
 int ath9k_htc_tx_start(struct ath9k_htc_priv *priv,
-		       struct sk_buff *skb, bool is_cab);
+		       struct sk_buff *skb, u8 slot, bool is_cab);
 void ath9k_tx_cleanup(struct ath9k_htc_priv *priv);
 bool ath9k_htc_txq_setup(struct ath9k_htc_priv *priv, int subtype);
 int ath9k_htc_cabq_setup(struct ath9k_htc_priv *priv);
@@ -541,6 +542,8 @@ int ath_htc_txq_update(struct ath9k_htc_priv *priv, int qnum,
 		       struct ath9k_tx_queue_info *qinfo);
 void ath9k_htc_check_stop_queues(struct ath9k_htc_priv *priv);
 void ath9k_htc_check_wake_queues(struct ath9k_htc_priv *priv);
+int ath9k_htc_tx_get_slot(struct ath9k_htc_priv *priv);
+void ath9k_htc_tx_clear_slot(struct ath9k_htc_priv *priv, int slot);
 
 int ath9k_rx_init(struct ath9k_htc_priv *priv);
 void ath9k_rx_cleanup(struct ath9k_htc_priv *priv);

drivers/net/wireless/ath/ath9k/htc_drv_beacon.c

@@ -299,7 +299,7 @@ static void ath9k_htc_send_buffered(struct ath9k_htc_priv *priv,
 	struct ieee80211_vif *vif;
 	struct sk_buff *skb;
 	struct ieee80211_hdr *hdr;
-	int padpos, padsize, ret;
+	int padpos, padsize, ret, tx_slot;
 
 	spin_lock_bh(&priv->beacon_lock);
 
@@ -321,11 +321,20 @@ static void ath9k_htc_send_buffered(struct ath9k_htc_priv *priv,
 			memmove(skb->data, skb->data + padsize, padpos);
 		}
 
-		ret = ath9k_htc_tx_start(priv, skb, true);
+		tx_slot = ath9k_htc_tx_get_slot(priv);
+		if (tx_slot != 0) {
+			ath_dbg(common, ATH_DBG_XMIT, "No free CAB slot\n");
+			dev_kfree_skb_any(skb);
+			goto next;
+		}
+
+		ret = ath9k_htc_tx_start(priv, skb, tx_slot, true);
 		if (ret != 0) {
-			ath_dbg(common, ATH_DBG_FATAL,
-				"Failed to send CAB frame\n");
+			ath9k_htc_tx_clear_slot(priv, tx_slot);
 			dev_kfree_skb_any(skb);
+
+			ath_dbg(common, ATH_DBG_XMIT,
+				"Failed to send CAB frame\n");
 		} else {
 			spin_lock_bh(&priv->tx.tx_lock);
 			priv->tx.queued_cnt++;

drivers/net/wireless/ath/ath9k/htc_drv_main.c

@@ -834,7 +834,7 @@ static void ath9k_htc_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 	struct ieee80211_hdr *hdr;
 	struct ath9k_htc_priv *priv = hw->priv;
 	struct ath_common *common = ath9k_hw_common(priv->ah);
-	int padpos, padsize, ret;
+	int padpos, padsize, ret, slot;
 
 	hdr = (struct ieee80211_hdr *) skb->data;
 
@@ -850,16 +850,24 @@ static void ath9k_htc_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 		memmove(skb->data, skb->data + padsize, padpos);
 	}
 
-	ret = ath9k_htc_tx_start(priv, skb, false);
+	slot = ath9k_htc_tx_get_slot(priv);
+	if (slot < 0) {
+		ath_dbg(common, ATH_DBG_XMIT, "No free TX slot\n");
+		goto fail_tx;
+	}
+
+	ret = ath9k_htc_tx_start(priv, skb, slot, false);
 	if (ret != 0) {
 		ath_dbg(common, ATH_DBG_XMIT, "Tx failed\n");
-		goto fail_tx;
+		goto clear_slot;
 	}
 
 	ath9k_htc_check_stop_queues(priv);
 
 	return;
 
+clear_slot:
+	ath9k_htc_tx_clear_slot(priv, slot);
 fail_tx:
 	dev_kfree_skb_any(skb);
 }

drivers/net/wireless/ath/ath9k/htc_drv_txrx.c

@@ -76,6 +76,29 @@ void ath9k_htc_check_wake_queues(struct ath9k_htc_priv *priv)
 	spin_unlock_bh(&priv->tx.tx_lock);
 }
 
+int ath9k_htc_tx_get_slot(struct ath9k_htc_priv *priv)
+{
+	int slot;
+
+	spin_lock_bh(&priv->tx.tx_lock);
+	slot = find_first_zero_bit(priv->tx.tx_slot, MAX_TX_BUF_NUM);
+	if (slot >= MAX_TX_BUF_NUM) {
+		spin_unlock_bh(&priv->tx.tx_lock);
+		return -ENOBUFS;
+	}
+	__set_bit(slot, priv->tx.tx_slot);
+	spin_unlock_bh(&priv->tx.tx_lock);
+
+	return slot;
+}
+
+void ath9k_htc_tx_clear_slot(struct ath9k_htc_priv *priv, int slot)
+{
+	spin_lock_bh(&priv->tx.tx_lock);
+	__clear_bit(slot, priv->tx.tx_slot);
+	spin_unlock_bh(&priv->tx.tx_lock);
+}
+
 static enum htc_endpoint_id get_htc_epid(struct ath9k_htc_priv *priv,
 					 u16 qnum)
 {
@@ -104,28 +127,38 @@ static enum htc_endpoint_id get_htc_epid(struct ath9k_htc_priv *priv,
 	return epid;
 }
 
+/*
+ * Removes the driver header and returns the TX slot number
+ */
 static inline int strip_drv_header(struct ath9k_htc_priv *priv,
 				   struct sk_buff *skb)
 {
 	struct ath_common *common = ath9k_hw_common(priv->ah);
 	struct ath9k_htc_tx_ctl *tx_ctl;
+	int slot;
 
 	tx_ctl = HTC_SKB_CB(skb);
 
 	if (tx_ctl->epid == priv->mgmt_ep) {
+		struct tx_mgmt_hdr *tx_mhdr =
+			(struct tx_mgmt_hdr *)skb->data;
+		slot = tx_mhdr->cookie;
 		skb_pull(skb, sizeof(struct tx_mgmt_hdr));
 	} else if ((tx_ctl->epid == priv->data_bk_ep) ||
 		   (tx_ctl->epid == priv->data_be_ep) ||
 		   (tx_ctl->epid == priv->data_vi_ep) ||
 		   (tx_ctl->epid == priv->data_vo_ep) ||
 		   (tx_ctl->epid == priv->cab_ep)) {
+		struct tx_frame_hdr *tx_fhdr =
+			(struct tx_frame_hdr *)skb->data;
+		slot = tx_fhdr->cookie;
 		skb_pull(skb, sizeof(struct tx_frame_hdr));
 	} else {
 		ath_err(common, "Unsupported EPID: %d\n", tx_ctl->epid);
-		return -EINVAL;
+		slot = -EINVAL;
 	}
 
-	return 0;
+	return slot;
 }
 
 int ath_htc_txq_update(struct ath9k_htc_priv *priv, int qnum,
@@ -155,7 +188,8 @@ int ath_htc_txq_update(struct ath9k_htc_priv *priv, int qnum,
 }
 
 int ath9k_htc_tx_start(struct ath9k_htc_priv *priv,
-		       struct sk_buff *skb, bool is_cab)
+		       struct sk_buff *skb,
+		       u8 slot, bool is_cab)
 {
 	struct ieee80211_hdr *hdr;
 	struct ieee80211_mgmt *mgmt;
@@ -212,6 +246,7 @@ int ath9k_htc_tx_start(struct ath9k_htc_priv *priv,
 
 		tx_hdr.node_idx = sta_idx;
 		tx_hdr.vif_idx = vif_idx;
+		tx_hdr.cookie = slot;
 
 		if (tx_info->flags & IEEE80211_TX_CTL_AMPDU) {
 			tx_ctl->type = ATH9K_HTC_AMPDU;
@@ -274,6 +309,7 @@ int ath9k_htc_tx_start(struct ath9k_htc_priv *priv,
 		mgmt_hdr.vif_idx = vif_idx;
 		mgmt_hdr.tidno = 0;
 		mgmt_hdr.flags = 0;
+		mgmt_hdr.cookie = slot;
 
 		mgmt_hdr.key_type = ath9k_cmn_get_hw_crypto_keytype(skb);
 		if (mgmt_hdr.key_type == ATH9K_KEY_TYPE_CLEAR)
@@ -313,10 +349,12 @@ void ath9k_tx_tasklet(unsigned long data)
 	struct sk_buff *skb = NULL;
 	__le16 fc;
 	bool txok;
+	int slot;
 
 	while ((skb = skb_dequeue(&priv->tx.tx_queue)) != NULL) {
 
-		if (strip_drv_header(priv, skb) < 0) {
+		slot = strip_drv_header(priv, skb);
+		if (slot < 0) {
 			dev_kfree_skb_any(skb);
 			continue;
 		}
@@ -347,8 +385,7 @@ void ath9k_tx_tasklet(unsigned long data)
 		sta = ieee80211_find_sta(vif, hdr->addr1);
 		if (!sta) {
 			rcu_read_unlock();
-			ieee80211_tx_status(priv->hw, skb);
-			continue;
+			goto send_mac80211;
 		}
 
 		/* Check if we need to start aggregation */
@@ -380,6 +417,8 @@ void ath9k_tx_tasklet(unsigned long data)
 			priv->tx.queued_cnt = 0;
 		spin_unlock_bh(&priv->tx.tx_lock);
 
+		ath9k_htc_tx_clear_slot(priv, slot);
+
 		/* Send status to mac80211 */
 		ieee80211_tx_status(priv->hw, skb);
 	}