mac80211: proper STA info locking

As discussed earlier, we can unify locking in struct sta_info
and use just a single spinlock protecting all members of the
structure that need protection. Many don't, but one of the
especially bad ones is the 'flags' member that can currently
be clobbered when RX and TX is being processed on different
CPUs at the same time.

Because having four spinlocks for different, mostly exclusive
parts of a single structure is overkill, this patch also kills
the ampdu and mesh plink spinlocks and uses just a single one
for everything. Because none of the spinlocks are nested, this
is safe.

It remains to be seen whether or not we should make the sta
flags use atomic bit operations instead, for now though this
is a safe thing and using atomic operations instead will be
very simple using the new static inline functions this patch
introduces for accessing sta->flags.

Since spin_lock_bh() is used with this lock, there shouldn't
be any contention even if aggregation is enabled at around the
same time as both requires frame transmission/reception which
is in a bh context.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Tomas Winkler <tomasw@gmail.com>
Cc: Ron Rindjunsky <ron.rindjunsky@intel.com>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 699d97b..3cef80d 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -602,6 +602,7 @@
 	 */
 
 	if (params->station_flags & STATION_FLAG_CHANGED) {
+		spin_lock_bh(&sta->lock);
 		sta->flags &= ~WLAN_STA_AUTHORIZED;
 		if (params->station_flags & STATION_FLAG_AUTHORIZED)
 			sta->flags |= WLAN_STA_AUTHORIZED;
@@ -613,6 +614,7 @@
 		sta->flags &= ~WLAN_STA_WME;
 		if (params->station_flags & STATION_FLAG_WME)
 			sta->flags |= WLAN_STA_WME;
+		spin_unlock_bh(&sta->lock);
 	}
 
 	/*
diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c
index 676a932..1f00273 100644
--- a/net/mac80211/debugfs_sta.c
+++ b/net/mac80211/debugfs_sta.c
@@ -74,14 +74,15 @@
 {
 	char buf[100];
 	struct sta_info *sta = file->private_data;
+	u32 staflags = get_sta_flags(sta);
 	int res = scnprintf(buf, sizeof(buf), "%s%s%s%s%s%s%s",
-		sta->flags & WLAN_STA_AUTH ? "AUTH\n" : "",
-		sta->flags & WLAN_STA_ASSOC ? "ASSOC\n" : "",
-		sta->flags & WLAN_STA_PS ? "PS\n" : "",
-		sta->flags & WLAN_STA_AUTHORIZED ? "AUTHORIZED\n" : "",
-		sta->flags & WLAN_STA_SHORT_PREAMBLE ? "SHORT PREAMBLE\n" : "",
-		sta->flags & WLAN_STA_WME ? "WME\n" : "",
-		sta->flags & WLAN_STA_WDS ? "WDS\n" : "");
+		staflags & WLAN_STA_AUTH ? "AUTH\n" : "",
+		staflags & WLAN_STA_ASSOC ? "ASSOC\n" : "",
+		staflags & WLAN_STA_PS ? "PS\n" : "",
+		staflags & WLAN_STA_AUTHORIZED ? "AUTHORIZED\n" : "",
+		staflags & WLAN_STA_SHORT_PREAMBLE ? "SHORT PREAMBLE\n" : "",
+		staflags & WLAN_STA_WME ? "WME\n" : "",
+		staflags & WLAN_STA_WDS ? "WDS\n" : "");
 	return simple_read_from_buffer(userbuf, count, ppos, buf, res);
 }
 STA_OPS(flags);
diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index 88b211a..d4893bd 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -321,7 +321,7 @@
 		 * some hardware cannot handle TKIP with QoS, so
 		 * we indicate whether QoS could be in use.
 		 */
-		if (sta->flags & WLAN_STA_WME)
+		if (test_sta_flags(sta, WLAN_STA_WME))
 			key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA;
 
 		/*
@@ -342,7 +342,7 @@
 			/* same here, the AP could be using QoS */
 			ap = sta_info_get(key->local, key->sdata->u.sta.bssid);
 			if (ap) {
-				if (ap->flags & WLAN_STA_WME)
+				if (test_sta_flags(ap, WLAN_STA_WME))
 					key->conf.flags |=
 						IEEE80211_KEY_FLAG_WMM_STA;
 			}
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 55e7611..f277407 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -346,6 +346,7 @@
 			goto err_del_interface;
 		}
 
+		/* no locking required since STA is not live yet */
 		sta->flags |= WLAN_STA_AUTHORIZED;
 
 		res = sta_info_insert(sta);
@@ -588,7 +589,7 @@
 		return -ENOENT;
 	}
 
-	spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
+	spin_lock_bh(&sta->lock);
 
 	/* we have tried too many times, receiver does not want A-MPDU */
 	if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
@@ -691,7 +692,7 @@
 	spin_unlock_bh(&local->mdev->queue_lock);
 	ret = -EBUSY;
 start_ba_exit:
-	spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+	spin_unlock_bh(&sta->lock);
 	rcu_read_unlock();
 	return ret;
 }
@@ -719,7 +720,7 @@
 
 	/* check if the TID is in aggregation */
 	state = &sta->ampdu_mlme.tid_state_tx[tid];
-	spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
+	spin_lock_bh(&sta->lock);
 
 	if (*state != HT_AGG_STATE_OPERATIONAL) {
 		ret = -ENOENT;
@@ -749,7 +750,7 @@
 	}
 
 stop_BA_exit:
-	spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+	spin_unlock_bh(&sta->lock);
 	rcu_read_unlock();
 	return ret;
 }
@@ -778,12 +779,12 @@
 	}
 
 	state = &sta->ampdu_mlme.tid_state_tx[tid];
-	spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
+	spin_lock_bh(&sta->lock);
 
 	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
 		printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
 				*state);
-		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+		spin_unlock_bh(&sta->lock);
 		rcu_read_unlock();
 		return;
 	}
@@ -796,7 +797,7 @@
 		printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
 		ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
 	}
-	spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+	spin_unlock_bh(&sta->lock);
 	rcu_read_unlock();
 }
 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
@@ -830,10 +831,10 @@
 	}
 	state = &sta->ampdu_mlme.tid_state_tx[tid];
 
-	spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
+	spin_lock_bh(&sta->lock);
 	if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
 		printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
-		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+		spin_unlock_bh(&sta->lock);
 		rcu_read_unlock();
 		return;
 	}
@@ -860,7 +861,7 @@
 	sta->ampdu_mlme.addba_req_num[tid] = 0;
 	kfree(sta->ampdu_mlme.tid_tx[tid]);
 	sta->ampdu_mlme.tid_tx[tid] = NULL;
-	spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+	spin_unlock_bh(&sta->lock);
 
 	rcu_read_unlock();
 }
@@ -1315,7 +1316,7 @@
 	 * packet. If the STA went to power save mode, this will happen
 	 * happen when it wakes up for the next time.
 	 */
-	sta->flags |= WLAN_STA_CLEAR_PS_FILT;
+	set_sta_flags(sta, WLAN_STA_CLEAR_PS_FILT);
 
 	/*
 	 * This code races in the following way:
@@ -1347,7 +1348,7 @@
 	 *      can be unknown, for example with different interrupt status
 	 *	bits.
 	 */
-	if (sta->flags & WLAN_STA_PS &&
+	if (test_sta_flags(sta, WLAN_STA_PS) &&
 	    skb_queue_len(&sta->tx_filtered) < STA_MAX_TX_BUFFER) {
 		ieee80211_remove_tx_extra(local, sta->key, skb,
 					  &status->control);
@@ -1355,7 +1356,7 @@
 		return;
 	}
 
-	if (!(sta->flags & WLAN_STA_PS) &&
+	if (!test_sta_flags(sta, WLAN_STA_PS) &&
 	    !(status->control.flags & IEEE80211_TXCTL_REQUEUE)) {
 		/* Software retry the packet once */
 		status->control.flags |= IEEE80211_TXCTL_REQUEUE;
@@ -1370,7 +1371,7 @@
 		       "queue_len=%d PS=%d @%lu\n",
 		       wiphy_name(local->hw.wiphy),
 		       skb_queue_len(&sta->tx_filtered),
-		       !!(sta->flags & WLAN_STA_PS), jiffies);
+		       !!test_sta_flags(sta, WLAN_STA_PS), jiffies);
 	dev_kfree_skb(skb);
 }
 
@@ -1399,7 +1400,7 @@
 		struct sta_info *sta;
 		sta = sta_info_get(local, hdr->addr1);
 		if (sta) {
-			if (sta->flags & WLAN_STA_PS) {
+			if (test_sta_flags(sta, WLAN_STA_PS)) {
 				/*
 				 * The STA is in power save mode, so assume
 				 * that this TX packet failed because of that.
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
index 37f0c2b..9efeb1f 100644
--- a/net/mac80211/mesh_plink.c
+++ b/net/mac80211/mesh_plink.c
@@ -79,7 +79,7 @@
  *
  * @sta: mes peer link to restart
  *
- * Locking: this function must be called holding sta->plink_lock
+ * Locking: this function must be called holding sta->lock
  */
 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
 {
@@ -105,7 +105,7 @@
 	if (!sta)
 		return NULL;
 
-	sta->flags |= WLAN_STA_AUTHORIZED;
+	sta->flags = WLAN_STA_AUTHORIZED;
 	sta->supp_rates[local->hw.conf.channel->band] = rates;
 
 	return sta;
@@ -118,7 +118,7 @@
  *
  * All mesh paths with this peer as next hop will be flushed
  *
- * Locking: the caller must hold sta->plink_lock
+ * Locking: the caller must hold sta->lock
  */
 static void __mesh_plink_deactivate(struct sta_info *sta)
 {
@@ -139,9 +139,9 @@
  */
 void mesh_plink_deactivate(struct sta_info *sta)
 {
-	spin_lock_bh(&sta->plink_lock);
+	spin_lock_bh(&sta->lock);
 	__mesh_plink_deactivate(sta);
-	spin_unlock_bh(&sta->plink_lock);
+	spin_unlock_bh(&sta->lock);
 }
 
 static int mesh_plink_frame_tx(struct net_device *dev,
@@ -270,10 +270,10 @@
 	 */
 	sta = (struct sta_info *) data;
 
-	spin_lock_bh(&sta->plink_lock);
+	spin_lock_bh(&sta->lock);
 	if (sta->ignore_plink_timer) {
 		sta->ignore_plink_timer = false;
-		spin_unlock_bh(&sta->plink_lock);
+		spin_unlock_bh(&sta->lock);
 		return;
 	}
 	mpl_dbg("Mesh plink timer for %s fired on state %d\n",
@@ -298,7 +298,7 @@
 					     rand % sta->plink_timeout;
 			++sta->plink_retries;
 			mod_plink_timer(sta, sta->plink_timeout);
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			mesh_plink_frame_tx(dev, PLINK_OPEN, sta->addr, llid,
 					    0, 0);
 			break;
@@ -311,7 +311,7 @@
 			reason = cpu_to_le16(MESH_CONFIRM_TIMEOUT);
 		sta->plink_state = PLINK_HOLDING;
 		mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
-		spin_unlock_bh(&sta->plink_lock);
+		spin_unlock_bh(&sta->lock);
 		mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid, plid,
 				    reason);
 		break;
@@ -319,10 +319,10 @@
 		/* holding timer */
 		del_timer(&sta->plink_timer);
 		mesh_plink_fsm_restart(sta);
-		spin_unlock_bh(&sta->plink_lock);
+		spin_unlock_bh(&sta->lock);
 		break;
 	default:
-		spin_unlock_bh(&sta->plink_lock);
+		spin_unlock_bh(&sta->lock);
 		break;
 	}
 }
@@ -344,16 +344,16 @@
 	DECLARE_MAC_BUF(mac);
 #endif
 
-	spin_lock_bh(&sta->plink_lock);
+	spin_lock_bh(&sta->lock);
 	get_random_bytes(&llid, 2);
 	sta->llid = llid;
 	if (sta->plink_state != PLINK_LISTEN) {
-		spin_unlock_bh(&sta->plink_lock);
+		spin_unlock_bh(&sta->lock);
 		return -EBUSY;
 	}
 	sta->plink_state = PLINK_OPN_SNT;
 	mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
-	spin_unlock_bh(&sta->plink_lock);
+	spin_unlock_bh(&sta->lock);
 	mpl_dbg("Mesh plink: starting establishment with %s\n",
 		print_mac(mac, sta->addr));
 
@@ -367,10 +367,10 @@
 	DECLARE_MAC_BUF(mac);
 #endif
 
-	spin_lock_bh(&sta->plink_lock);
+	spin_lock_bh(&sta->lock);
 	__mesh_plink_deactivate(sta);
 	sta->plink_state = PLINK_BLOCKED;
-	spin_unlock_bh(&sta->plink_lock);
+	spin_unlock_bh(&sta->lock);
 }
 
 int mesh_plink_close(struct sta_info *sta)
@@ -383,14 +383,14 @@
 
 	mpl_dbg("Mesh plink: closing link with %s\n",
 			print_mac(mac, sta->addr));
-	spin_lock_bh(&sta->plink_lock);
+	spin_lock_bh(&sta->lock);
 	sta->reason = cpu_to_le16(MESH_LINK_CANCELLED);
 	reason = sta->reason;
 
 	if (sta->plink_state == PLINK_LISTEN ||
 	    sta->plink_state == PLINK_BLOCKED) {
 		mesh_plink_fsm_restart(sta);
-		spin_unlock_bh(&sta->plink_lock);
+		spin_unlock_bh(&sta->lock);
 		return 0;
 	} else if (sta->plink_state == PLINK_ESTAB) {
 		__mesh_plink_deactivate(sta);
@@ -402,7 +402,7 @@
 	sta->plink_state = PLINK_HOLDING;
 	llid = sta->llid;
 	plid = sta->plid;
-	spin_unlock_bh(&sta->plink_lock);
+	spin_unlock_bh(&sta->lock);
 	mesh_plink_frame_tx(sta->sdata->dev, PLINK_CLOSE, sta->addr, llid,
 			    plid, reason);
 	return 0;
@@ -490,7 +490,7 @@
 			/* avoid warning */
 			break;
 		}
-		spin_lock_bh(&sta->plink_lock);
+		spin_lock_bh(&sta->lock);
 	} else if (!sta) {
 		/* ftype == PLINK_OPEN */
 		u64 rates;
@@ -512,9 +512,9 @@
 			return;
 		}
 		event = OPN_ACPT;
-		spin_lock_bh(&sta->plink_lock);
+		spin_lock_bh(&sta->lock);
 	} else {
-		spin_lock_bh(&sta->plink_lock);
+		spin_lock_bh(&sta->lock);
 		switch (ftype) {
 		case PLINK_OPEN:
 			if (!mesh_plink_free_count(sdata) ||
@@ -551,7 +551,7 @@
 			break;
 		default:
 			mpl_dbg("Mesh plink: unknown frame subtype\n");
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			rcu_read_unlock();
 			return;
 		}
@@ -568,7 +568,7 @@
 		switch (event) {
 		case CLS_ACPT:
 			mesh_plink_fsm_restart(sta);
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			break;
 		case OPN_ACPT:
 			sta->plink_state = PLINK_OPN_RCVD;
@@ -576,14 +576,14 @@
 			get_random_bytes(&llid, 2);
 			sta->llid = llid;
 			mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			mesh_plink_frame_tx(dev, PLINK_OPEN, sta->addr, llid,
 					    0, 0);
 			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr,
 					    llid, plid, 0);
 			break;
 		default:
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			break;
 		}
 		break;
@@ -603,7 +603,7 @@
 				sta->ignore_plink_timer = true;
 
 			llid = sta->llid;
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,
 					    plid, reason);
 			break;
@@ -612,7 +612,7 @@
 			sta->plink_state = PLINK_OPN_RCVD;
 			sta->plid = plid;
 			llid = sta->llid;
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr, llid,
 					    plid, 0);
 			break;
@@ -622,10 +622,10 @@
 					     dot11MeshConfirmTimeout(sdata)))
 				sta->ignore_plink_timer = true;
 
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			break;
 		default:
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			break;
 		}
 		break;
@@ -645,13 +645,13 @@
 				sta->ignore_plink_timer = true;
 
 			llid = sta->llid;
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,
 					    plid, reason);
 			break;
 		case OPN_ACPT:
 			llid = sta->llid;
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr, llid,
 					    plid, 0);
 			break;
@@ -659,12 +659,12 @@
 			del_timer(&sta->plink_timer);
 			sta->plink_state = PLINK_ESTAB;
 			mesh_plink_inc_estab_count(sdata);
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			mpl_dbg("Mesh plink with %s ESTABLISHED\n",
 					print_mac(mac, sta->addr));
 			break;
 		default:
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			break;
 		}
 		break;
@@ -684,7 +684,7 @@
 				sta->ignore_plink_timer = true;
 
 			llid = sta->llid;
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,
 					    plid, reason);
 			break;
@@ -692,14 +692,14 @@
 			del_timer(&sta->plink_timer);
 			sta->plink_state = PLINK_ESTAB;
 			mesh_plink_inc_estab_count(sdata);
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			mpl_dbg("Mesh plink with %s ESTABLISHED\n",
 					print_mac(mac, sta->addr));
 			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr, llid,
 					    plid, 0);
 			break;
 		default:
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			break;
 		}
 		break;
@@ -713,18 +713,18 @@
 			sta->plink_state = PLINK_HOLDING;
 			llid = sta->llid;
 			mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,
 					    plid, reason);
 			break;
 		case OPN_ACPT:
 			llid = sta->llid;
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr, llid,
 					    plid, 0);
 			break;
 		default:
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			break;
 		}
 		break;
@@ -734,7 +734,7 @@
 			if (del_timer(&sta->plink_timer))
 				sta->ignore_plink_timer = 1;
 			mesh_plink_fsm_restart(sta);
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			break;
 		case OPN_ACPT:
 		case CNF_ACPT:
@@ -742,19 +742,19 @@
 		case CNF_RJCT:
 			llid = sta->llid;
 			reason = sta->reason;
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,
 					    plid, reason);
 			break;
 		default:
-			spin_unlock_bh(&sta->plink_lock);
+			spin_unlock_bh(&sta->lock);
 		}
 		break;
 	default:
 		/* should not get here, PLINK_BLOCKED is dealt with at the
 		 * beggining of the function
 		 */
-		spin_unlock_bh(&sta->plink_lock);
+		spin_unlock_bh(&sta->lock);
 		break;
 	}
 
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 108c6fc..6c4b27b 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1241,7 +1241,7 @@
 
 
 	/* examine state machine */
-	spin_lock_bh(&sta->ampdu_mlme.ampdu_rx);
+	spin_lock_bh(&sta->lock);
 
 	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_IDLE) {
 #ifdef CONFIG_MAC80211_HT_DEBUG
@@ -1308,7 +1308,7 @@
 	tid_agg_rx->stored_mpdu_num = 0;
 	status = WLAN_STATUS_SUCCESS;
 end:
-	spin_unlock_bh(&sta->ampdu_mlme.ampdu_rx);
+	spin_unlock_bh(&sta->lock);
 
 end_no_lock:
 	ieee80211_send_addba_resp(sta->sdata->dev, sta->addr, tid,
@@ -1340,10 +1340,10 @@
 
 	state = &sta->ampdu_mlme.tid_state_tx[tid];
 
-	spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
+	spin_lock_bh(&sta->lock);
 
 	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
-		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+		spin_unlock_bh(&sta->lock);
 		printk(KERN_DEBUG "state not HT_ADDBA_REQUESTED_MSK:"
 			"%d\n", *state);
 		goto addba_resp_exit;
@@ -1351,7 +1351,7 @@
 
 	if (mgmt->u.action.u.addba_resp.dialog_token !=
 		sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
-		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+		spin_unlock_bh(&sta->lock);
 #ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 #endif /* CONFIG_MAC80211_HT_DEBUG */
@@ -1375,7 +1375,7 @@
 			ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
 		}
 
-		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+		spin_unlock_bh(&sta->lock);
 		printk(KERN_DEBUG "recipient accepted agg: tid %d \n", tid);
 	} else {
 		printk(KERN_DEBUG "recipient rejected agg: tid %d \n", tid);
@@ -1383,7 +1383,7 @@
 		sta->ampdu_mlme.addba_req_num[tid]++;
 		/* this will allow the state check in stop_BA_session */
 		*state = HT_AGG_STATE_OPERATIONAL;
-		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+		spin_unlock_bh(&sta->lock);
 		ieee80211_stop_tx_ba_session(hw, sta->addr, tid,
 					     WLAN_BACK_INITIATOR);
 	}
@@ -1453,17 +1453,17 @@
 	}
 
 	/* check if TID is in operational state */
-	spin_lock_bh(&sta->ampdu_mlme.ampdu_rx);
+	spin_lock_bh(&sta->lock);
 	if (sta->ampdu_mlme.tid_state_rx[tid]
 				!= HT_AGG_STATE_OPERATIONAL) {
-		spin_unlock_bh(&sta->ampdu_mlme.ampdu_rx);
+		spin_unlock_bh(&sta->lock);
 		rcu_read_unlock();
 		return;
 	}
 	sta->ampdu_mlme.tid_state_rx[tid] =
 		HT_AGG_STATE_REQ_STOP_BA_MSK |
 		(initiator << HT_AGG_STATE_INITIATOR_SHIFT);
-	spin_unlock_bh(&sta->ampdu_mlme.ampdu_rx);
+	spin_unlock_bh(&sta->lock);
 
 	/* stop HW Rx aggregation. ampdu_action existence
 	 * already verified in session init so we add the BUG_ON */
@@ -1540,10 +1540,10 @@
 		ieee80211_sta_stop_rx_ba_session(dev, sta->addr, tid,
 						 WLAN_BACK_INITIATOR, 0);
 	else { /* WLAN_BACK_RECIPIENT */
-		spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
+		spin_lock_bh(&sta->lock);
 		sta->ampdu_mlme.tid_state_tx[tid] =
 				HT_AGG_STATE_OPERATIONAL;
-		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+		spin_unlock_bh(&sta->lock);
 		ieee80211_stop_tx_ba_session(&local->hw, sta->addr, tid,
 					     WLAN_BACK_RECIPIENT);
 	}
@@ -1580,9 +1580,9 @@
 
 	state = &sta->ampdu_mlme.tid_state_tx[tid];
 	/* check if the TID waits for addBA response */
-	spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
+	spin_lock_bh(&sta->lock);
 	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
-		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+		spin_unlock_bh(&sta->lock);
 		*state = HT_AGG_STATE_IDLE;
 		printk(KERN_DEBUG "timer expired on tid %d but we are not "
 				"expecting addBA response there", tid);
@@ -1593,7 +1593,7 @@
 
 	/* go through the state check in stop_BA_session */
 	*state = HT_AGG_STATE_OPERATIONAL;
-	spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+	spin_unlock_bh(&sta->lock);
 	ieee80211_stop_tx_ba_session(hw, temp_sta->addr, tid,
 				     WLAN_BACK_INITIATOR);
 
@@ -1984,8 +1984,8 @@
 	 *	  to between the sta_info_alloc() and sta_info_insert() above.
 	 */
 
-	sta->flags |= WLAN_STA_AUTH | WLAN_STA_ASSOC | WLAN_STA_ASSOC_AP |
-		      WLAN_STA_AUTHORIZED;
+	set_sta_flags(sta, WLAN_STA_AUTH | WLAN_STA_ASSOC | WLAN_STA_ASSOC_AP |
+			   WLAN_STA_AUTHORIZED);
 
 	rates = 0;
 	basic_rates = 0;
@@ -2044,7 +2044,7 @@
 	rate_control_rate_init(sta, local);
 
 	if (elems.wmm_param) {
-		sta->flags |= WLAN_STA_WME;
+		set_sta_flags(sta, WLAN_STA_WME);
 		rcu_read_unlock();
 		ieee80211_sta_wmm_params(dev, ifsta, elems.wmm_param,
 					 elems.wmm_param_len);
@@ -4237,7 +4237,7 @@
 	if (!sta)
 		return NULL;
 
-	sta->flags |= WLAN_STA_AUTHORIZED;
+	set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 
 	sta->supp_rates[local->hw.conf.channel->band] =
 		sdata->u.sta.supp_rates_bits[local->hw.conf.channel->band];
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index e8b89c8..b399e09 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -479,7 +479,7 @@
 		      ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL &&
 		       (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) &&
 		     rx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
-		     (!rx->sta || !(rx->sta->flags & WLAN_STA_ASSOC)))) {
+		     (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 		if ((!(rx->fc & IEEE80211_FCTL_FROMDS) &&
 		     !(rx->fc & IEEE80211_FCTL_TODS) &&
 		     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)
@@ -630,8 +630,7 @@
 
 	if (sdata->bss)
 		atomic_inc(&sdata->bss->num_sta_ps);
-	sta->flags |= WLAN_STA_PS;
-	sta->flags &= ~WLAN_STA_PSPOLL;
+	set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 	printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
 	       dev->name, print_mac(mac, sta->addr), sta->aid);
@@ -652,7 +651,7 @@
 	if (sdata->bss)
 		atomic_dec(&sdata->bss->num_sta_ps);
 
-	sta->flags &= ~(WLAN_STA_PS | WLAN_STA_PSPOLL);
+	clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
 
 	if (!skb_queue_empty(&sta->ps_tx_buf))
 		sta_info_clear_tim_bit(sta);
@@ -727,9 +726,10 @@
 	if (!(rx->fc & IEEE80211_FCTL_MOREFRAGS)) {
 		/* Change STA power saving mode only in the end of a frame
 		 * exchange sequence */
-		if ((sta->flags & WLAN_STA_PS) && !(rx->fc & IEEE80211_FCTL_PM))
+		if (test_sta_flags(sta, WLAN_STA_PS) &&
+		    !(rx->fc & IEEE80211_FCTL_PM))
 			rx->sent_ps_buffered += ap_sta_ps_end(dev, sta);
-		else if (!(sta->flags & WLAN_STA_PS) &&
+		else if (!test_sta_flags(sta, WLAN_STA_PS) &&
 			 (rx->fc & IEEE80211_FCTL_PM))
 			ap_sta_ps_start(dev, sta);
 	}
@@ -983,7 +983,7 @@
 		 * Tell TX path to send one frame even though the STA may
 		 * still remain is PS mode after this frame exchange.
 		 */
-		rx->sta->flags |= WLAN_STA_PSPOLL;
+		set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
 
 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 		printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
@@ -1046,7 +1046,8 @@
 static int
 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
 {
-	if (unlikely(!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED))) {
+	if (unlikely(!rx->sta ||
+	    !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED))) {
 #ifdef CONFIG_MAC80211_DEBUG
 		if (net_ratelimit())
 			printk(KERN_DEBUG "%s: dropped frame "
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 631943e..baf5e47 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -202,14 +202,12 @@
 		dev_kfree_skb_any(skb);
 
 	for (i = 0; i <  STA_TID_NUM; i++) {
-		spin_lock_bh(&sta->ampdu_mlme.ampdu_rx);
+		spin_lock_bh(&sta->lock);
 		if (sta->ampdu_mlme.tid_rx[i])
 		  del_timer_sync(&sta->ampdu_mlme.tid_rx[i]->session_timer);
-		spin_unlock_bh(&sta->ampdu_mlme.ampdu_rx);
-		spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
 		if (sta->ampdu_mlme.tid_tx[i])
 		  del_timer_sync(&sta->ampdu_mlme.tid_tx[i]->addba_resp_timer);
-		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+		spin_unlock_bh(&sta->lock);
 	}
 
 	__sta_info_free(local, sta);
@@ -236,6 +234,8 @@
 	if (!sta)
 		return NULL;
 
+	spin_lock_init(&sta->lock);
+
 	memcpy(sta->addr, addr, ETH_ALEN);
 	sta->local = local;
 	sta->sdata = sdata;
@@ -249,8 +249,6 @@
 		return NULL;
 	}
 
-	spin_lock_init(&sta->ampdu_mlme.ampdu_rx);
-	spin_lock_init(&sta->ampdu_mlme.ampdu_tx);
 	for (i = 0; i < STA_TID_NUM; i++) {
 		/* timer_to_tid must be initialized with identity mapping to
 		 * enable session_timer's data differentiation. refer to
@@ -276,7 +274,6 @@
 
 #ifdef CONFIG_MAC80211_MESH
 	sta->plink_state = PLINK_LISTEN;
-	spin_lock_init(&sta->plink_lock);
 	init_timer(&sta->plink_timer);
 #endif
 
@@ -437,8 +434,7 @@
 
 	list_del(&(*sta)->list);
 
-	if ((*sta)->flags & WLAN_STA_PS) {
-		(*sta)->flags &= ~WLAN_STA_PS;
+	if (test_and_clear_sta_flags(*sta, WLAN_STA_PS)) {
 		if (sdata->bss)
 			atomic_dec(&sdata->bss->num_sta_ps);
 		__sta_info_clear_tim_bit(sdata->bss, *sta);
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index f8c95bc..97a61c3 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -129,23 +129,19 @@
  *
  * @tid_state_rx: TID's state in Rx session state machine.
  * @tid_rx: aggregation info for Rx per TID
- * @ampdu_rx: for locking sections in aggregation Rx flow
  * @tid_state_tx: TID's state in Tx session state machine.
  * @tid_tx: aggregation info for Tx per TID
  * @addba_req_num: number of times addBA request has been sent.
- * @ampdu_tx: for locking sectionsi in aggregation Tx flow
  * @dialog_token_allocator: dialog token enumerator for each new session;
  */
 struct sta_ampdu_mlme {
 	/* rx */
 	u8 tid_state_rx[STA_TID_NUM];
 	struct tid_ampdu_rx *tid_rx[STA_TID_NUM];
-	spinlock_t ampdu_rx;
 	/* tx */
 	u8 tid_state_tx[STA_TID_NUM];
 	struct tid_ampdu_tx *tid_tx[STA_TID_NUM];
 	u8 addba_req_num[STA_TID_NUM];
-	spinlock_t ampdu_tx;
 	u8 dialog_token_allocator;
 };
 
@@ -177,6 +173,8 @@
  * @rx_bytes: Number of bytes received from this STA
  * @supp_rates: Bitmap of supported rates (per band)
  * @ht_info: HT capabilities of this STA
+ * @lock: used for locking all fields that require locking, see comments
+ *	in the header file.
  */
 struct sta_info {
 	/* General information, mostly static */
@@ -187,6 +185,7 @@
 	struct ieee80211_key *key;
 	struct rate_control_ref *rate_ctrl;
 	void *rate_ctrl_priv;
+	spinlock_t lock;
 	struct ieee80211_ht_info ht_info;
 	u64 supp_rates[IEEE80211_NUM_BANDS];
 	u8 addr[ETH_ALEN];
@@ -199,7 +198,7 @@
 	 */
 	u8 pin_status;
 
-	/* frequently updated information, needs locking? */
+	/* frequently updated information, locked with lock spinlock */
 	u32 flags;
 
 	/*
@@ -251,7 +250,7 @@
 	int channel_use_raw;
 
 	/*
-	 * Aggregation information, comes with own locking.
+	 * Aggregation information, locked with lock.
 	 */
 	struct sta_ampdu_mlme ampdu_mlme;
 	u8 timer_to_tid[STA_TID_NUM];	/* identity mapping to ID timers */
@@ -270,9 +269,6 @@
 	enum plink_state plink_state;
 	u32 plink_timeout;
 	struct timer_list plink_timer;
-	spinlock_t plink_lock;	/* For peer_state reads / updates and other
-				   updates in the structure. Ensures robust
-				   transitions for the peerlink FSM */
 #endif
 
 #ifdef CONFIG_MAC80211_DEBUGFS
@@ -299,6 +295,64 @@
 	return PLINK_LISTEN;
 }
 
+static inline void set_sta_flags(struct sta_info *sta, const u32 flags)
+{
+	spin_lock_bh(&sta->lock);
+	sta->flags |= flags;
+	spin_unlock_bh(&sta->lock);
+}
+
+static inline void clear_sta_flags(struct sta_info *sta, const u32 flags)
+{
+	spin_lock_bh(&sta->lock);
+	sta->flags &= ~flags;
+	spin_unlock_bh(&sta->lock);
+}
+
+static inline void set_and_clear_sta_flags(struct sta_info *sta,
+					   const u32 set, const u32 clear)
+{
+	spin_lock_bh(&sta->lock);
+	sta->flags |= set;
+	sta->flags &= ~clear;
+	spin_unlock_bh(&sta->lock);
+}
+
+static inline u32 test_sta_flags(struct sta_info *sta, const u32 flags)
+{
+	u32 ret;
+
+	spin_lock_bh(&sta->lock);
+	ret = sta->flags & flags;
+	spin_unlock_bh(&sta->lock);
+
+	return ret;
+}
+
+static inline u32 test_and_clear_sta_flags(struct sta_info *sta,
+					   const u32 flags)
+{
+	u32 ret;
+
+	spin_lock_bh(&sta->lock);
+	ret = sta->flags & flags;
+	sta->flags &= ~flags;
+	spin_unlock_bh(&sta->lock);
+
+	return ret;
+}
+
+static inline u32 get_sta_flags(struct sta_info *sta)
+{
+	u32 ret;
+
+	spin_lock_bh(&sta->lock);
+	ret = sta->flags;
+	spin_unlock_bh(&sta->lock);
+
+	return ret;
+}
+
 
 /* Maximum number of concurrently registered stations */
 #define MAX_STA_COUNT 2007
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 3a03d78..5f31a62 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -256,7 +256,7 @@
 	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
 		return TX_CONTINUE;
 
-	sta_flags = tx->sta ? tx->sta->flags : 0;
+	sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
 
 	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
 		if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
@@ -391,6 +391,7 @@
 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
 {
 	struct sta_info *sta = tx->sta;
+	u32 staflags;
 	DECLARE_MAC_BUF(mac);
 
 	if (unlikely(!sta ||
@@ -398,8 +399,10 @@
 		      (tx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PROBE_RESP)))
 		return TX_CONTINUE;
 
-	if (unlikely((sta->flags & WLAN_STA_PS) &&
-		     !(sta->flags & WLAN_STA_PSPOLL))) {
+	staflags = get_sta_flags(sta);
+
+	if (unlikely((staflags & WLAN_STA_PS) &&
+		     !(staflags & WLAN_STA_PSPOLL))) {
 		struct ieee80211_tx_packet_data *pkt_data;
 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 		printk(KERN_DEBUG "STA %s aid %d: PS buffer (entries "
@@ -430,13 +433,13 @@
 		return TX_QUEUED;
 	}
 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
-	else if (unlikely(sta->flags & WLAN_STA_PS)) {
+	else if (unlikely(test_sta_flags(sta, WLAN_STA_PS))) {
 		printk(KERN_DEBUG "%s: STA %s in PS mode, but pspoll "
 		       "set -> send frame\n", tx->dev->name,
 		       print_mac(mac, sta->addr));
 	}
 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
-	sta->flags &= ~WLAN_STA_PSPOLL;
+	clear_sta_flags(sta, WLAN_STA_PSPOLL);
 
 	return TX_CONTINUE;
 }
@@ -697,7 +700,7 @@
 	if (((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) &&
 	    (tx->rate->flags & IEEE80211_RATE_SHORT_PREAMBLE) &&
 	    tx->sdata->bss_conf.use_short_preamble &&
-	    (!tx->sta || (tx->sta->flags & WLAN_STA_SHORT_PREAMBLE))) {
+	    (!tx->sta || test_sta_flags(tx->sta, WLAN_STA_SHORT_PREAMBLE))) {
 		tx->control->flags |= IEEE80211_TXCTL_SHORT_PREAMBLE;
 	}
 
@@ -1025,10 +1028,8 @@
 
 	if (!tx->sta)
 		control->flags |= IEEE80211_TXCTL_CLEAR_PS_FILT;
-	else if (tx->sta->flags & WLAN_STA_CLEAR_PS_FILT) {
+	else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
 		control->flags |= IEEE80211_TXCTL_CLEAR_PS_FILT;
-		tx->sta->flags &= ~WLAN_STA_CLEAR_PS_FILT;
-	}
 
 	hdrlen = ieee80211_get_hdrlen(tx->fc);
 	if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
@@ -1486,7 +1487,7 @@
 		rcu_read_lock();
 		sta = sta_info_get(local, hdr.addr1);
 		if (sta)
-			sta_flags = sta->flags;
+			sta_flags = get_sta_flags(sta);
 		rcu_read_unlock();
 	}