staging: wfx: relocate "buffered" information to sta_priv

It simplify the code if field buffered is hosted in the struct sta_priv
instead of in the struct wfx_link_entry. More globally, struct
wfx_link_entry has no real reasons to exist and should be dropped soon.
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200115135338.14374-47-Jerome.Pouiller@silabs.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wfx/data_tx.c

@@ -291,7 +291,6 @@ static int wfx_alloc_link_id(struct wfx_vif *wvif, const u8 *mac)
 
 		entry->status = WFX_LINK_RESERVE;
 		ether_addr_copy(entry->mac, mac);
-		memset(&entry->buffered, 0, WFX_MAX_TID);
 		wfx_tx_lock(wvif->wdev);
 
 		if (!schedule_work(&wvif->link_id_work))
@@ -434,6 +433,7 @@ static void wfx_tx_manage_pm(struct wfx_vif *wvif, struct ieee80211_hdr *hdr,
 			     struct ieee80211_sta *sta)
 {
 	u32 mask = ~BIT(tx_priv->raw_link_id);
+	struct wfx_sta_priv *sta_priv;
 
 	spin_lock_bh(&wvif->ps_state_lock);
 	if (ieee80211_is_auth(hdr->frame_control)) {
@@ -448,15 +448,17 @@ static void wfx_tx_manage_pm(struct wfx_vif *wvif, struct ieee80211_hdr *hdr,
 			schedule_work(&wvif->mcast_start_work);
 	}
 
-	if (tx_priv->raw_link_id) {
+	if (tx_priv->raw_link_id)
 		wvif->link_id_db[tx_priv->raw_link_id - 1].timestamp = jiffies;
-		if (tx_priv->tid < WFX_MAX_TID)
-			wvif->link_id_db[tx_priv->raw_link_id - 1].buffered[tx_priv->tid]++;
-	}
 	spin_unlock_bh(&wvif->ps_state_lock);
 
-	if (sta)
+	if (sta && tx_priv->tid < WFX_MAX_TID) {
+		sta_priv = (struct wfx_sta_priv *)&sta->drv_priv;
+		spin_lock_bh(&sta_priv->lock);
+		sta_priv->buffered[tx_priv->tid]++;
 		ieee80211_sta_set_buffered(sta, tx_priv->tid, true);
+		spin_unlock_bh(&sta_priv->lock);
+	}
 }
 
 static u8 wfx_tx_get_raw_link_id(struct wfx_vif *wvif,
@@ -789,31 +791,25 @@ void wfx_tx_confirm_cb(struct wfx_vif *wvif, const struct hif_cnf_tx *arg)
 	wfx_pending_remove(wvif->wdev, skb);
 }
 
-static void wfx_notify_buffered_tx(struct wfx_vif *wvif, struct sk_buff *skb,
-				   struct hif_req_tx *req)
+static void wfx_notify_buffered_tx(struct wfx_vif *wvif, struct sk_buff *skb)
 {
-	struct ieee80211_sta *sta;
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+	struct ieee80211_sta *sta;
+	struct wfx_sta_priv *sta_priv;
 	int tid = wfx_tx_get_tid(hdr);
-	int raw_link_id = req->queue_id.peer_sta_id;
-	u8 *buffered;
-
-	if (raw_link_id && tid < WFX_MAX_TID) {
-		buffered = wvif->link_id_db[raw_link_id - 1].buffered;
-
-		spin_lock_bh(&wvif->ps_state_lock);
-		WARN(!buffered[tid], "inconsistent notification");
-		buffered[tid]--;
-		spin_unlock_bh(&wvif->ps_state_lock);
-
-		if (!buffered[tid]) {
-			rcu_read_lock();
-			sta = ieee80211_find_sta(wvif->vif, hdr->addr1);
-			if (sta)
-				ieee80211_sta_set_buffered(sta, tid, false);
-			rcu_read_unlock();
-		}
+
+	rcu_read_lock(); // protect sta
+	sta = ieee80211_find_sta(wvif->vif, hdr->addr1);
+	if (sta && tid < WFX_MAX_TID) {
+		sta_priv = (struct wfx_sta_priv *)&sta->drv_priv;
+		spin_lock_bh(&sta_priv->lock);
+		WARN(!sta_priv->buffered[tid], "inconsistent notification");
+		sta_priv->buffered[tid]--;
+		if (!sta_priv->buffered[tid])
+			ieee80211_sta_set_buffered(sta, tid, false);
+		spin_unlock_bh(&sta_priv->lock);
 	}
+	rcu_read_unlock();
 }
 
 void wfx_skb_dtor(struct wfx_dev *wdev, struct sk_buff *skb)
@@ -827,7 +823,7 @@ void wfx_skb_dtor(struct wfx_dev *wdev, struct sk_buff *skb)
 
 	WARN_ON(!wvif);
 	skb_pull(skb, offset);
-	wfx_notify_buffered_tx(wvif, skb, req);
+	wfx_notify_buffered_tx(wvif, skb);
 	wfx_tx_policy_put(wvif, req->tx_flags.retry_policy_index);
 	ieee80211_tx_status_irqsafe(wdev->hw, skb);
 }

drivers/staging/wfx/data_tx.h

@@ -14,9 +14,6 @@
 #include "hif_api_cmd.h"
 #include "hif_api_mib.h"
 
-// FIXME: use IEEE80211_NUM_TIDS
-#define WFX_MAX_TID               8
-
 struct wfx_tx_priv;
 struct wfx_dev;
 struct wfx_vif;
@@ -33,7 +30,6 @@ struct wfx_link_entry {
 	enum wfx_link_status	status;
 	u8			mac[ETH_ALEN];
 	u8			old_mac[ETH_ALEN];
-	u8			buffered[WFX_MAX_TID];
 };
 
 struct tx_policy {

drivers/staging/wfx/sta.c

@@ -572,6 +572,7 @@ int wfx_sta_add(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 	struct wfx_sta_priv *sta_priv = (struct wfx_sta_priv *) &sta->drv_priv;
 	struct wfx_link_entry *entry;
 
+	spin_lock_init(&sta_priv->lock);
 	if (wvif->vif->type != NL80211_IFTYPE_AP)
 		return 0;
 

drivers/staging/wfx/sta.h

@@ -12,6 +12,9 @@
 
 #include "hif_api_cmd.h"
 
+// FIXME: use IEEE80211_NUM_TIDS
+#define WFX_MAX_TID               8
+
 struct wfx_dev;
 struct wfx_vif;
 
@@ -37,6 +40,9 @@ struct wfx_grp_addr_table {
 struct wfx_sta_priv {
 	int link_id;
 	int vif_id;
+	u8 buffered[WFX_MAX_TID];
+	// Ensure atomicity of "buffered" and calls to ieee80211_sta_set_buffered()
+	spinlock_t lock;
 };
 
 // mac80211 interface