From a622ab72b4dcfdf53e24b16e9530cb876979a00c Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Thu, 10 Jun 2010 10:21:39 +0200
Subject: mac80211: use RCU for TX aggregation

Currently we allocate some memory for each TX
aggregation session and additionally keep a
state bitmap indicating the state it is in.
By using RCU to protect the pointer, moving
the state into the structure and some locking
trickery we can avoid locking when the TX agg
session is fully operational.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
 net/mac80211/sta_info.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

(limited to 'net/mac80211/sta_info.c')

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index c426c572d98..06d8e00a253 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -246,14 +246,12 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
 	}
 
 	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
-		 * sta_rx_agg_session_timer_expired for useage */
+		/*
+		 * timer_to_tid must be initialized with identity mapping
+		 * to enable session_timer's data differentiation. See
+		 * sta_rx_agg_session_timer_expired for usage.
+		 */
 		sta->timer_to_tid[i] = i;
-		/* tx */
-		sta->ampdu_mlme.tid_state_tx[i] = HT_AGG_STATE_IDLE;
-		sta->ampdu_mlme.tid_tx[i] = NULL;
-		sta->ampdu_mlme.addba_req_num[i] = 0;
 	}
 	skb_queue_head_init(&sta->ps_tx_buf);
 	skb_queue_head_init(&sta->tx_filtered);
-- 
cgit v1.2.3-70-g09d2


From 0ab337032a0dfcd5f2527d3306d3deeba5f95b59 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Thu, 10 Jun 2010 10:21:42 +0200
Subject: mac80211: make TX aggregation start/stop request async

When the driver or rate control requests starting
or stopping an aggregation session, that currently
causes a direct callback into the driver, which
could potentially cause locking problems. Also,
the functions need to be callable from contexts
that cannot sleep, and thus will interfere with
making the ampdu_action callback sleeping.

To address these issues, add a new work item for
each station that will process any start or stop
requests out of line.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
 net/mac80211/agg-tx.c      | 177 ++++++++++++++++++++++++++++++++-------------
 net/mac80211/debugfs_sta.c |   5 +-
 net/mac80211/ht.c          |   2 +
 net/mac80211/ieee80211_i.h |   1 +
 net/mac80211/sta_info.c    |   1 +
 net/mac80211/sta_info.h    |   6 +-
 net/mac80211/tx.c          |   5 ++
 7 files changed, 139 insertions(+), 58 deletions(-)

(limited to 'net/mac80211/sta_info.c')

diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index 7f2042d3790..ee8bfe18b48 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -146,6 +146,13 @@ static int ___ieee80211_stop_tx_ba_session(
 	if (WARN_ON(!tid_tx))
 		return -ENOENT;
 
+	if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
+		/* not even started yet! */
+		rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
+		call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
+		return 0;
+	}
+
 #ifdef CONFIG_MAC80211_HT_DEBUG
 	printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
 	       sta->sta.addr, tid);
@@ -255,6 +262,94 @@ ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid)
 	__release(agg_queue);
 }
 
+static void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
+{
+	struct tid_ampdu_tx *tid_tx = sta->ampdu_mlme.tid_tx[tid];
+	struct ieee80211_local *local = sta->local;
+	struct ieee80211_sub_if_data *sdata = sta->sdata;
+	u16 start_seq_num;
+	int ret;
+
+	/*
+	 * While we're asking the driver about the aggregation,
+	 * stop the AC queue so that we don't have to worry
+	 * about frames that came in while we were doing that,
+	 * which would require us to put them to the AC pending
+	 * afterwards which just makes the code more complex.
+	 */
+	ieee80211_stop_queue_agg(local, tid);
+
+	clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
+
+	/*
+	 * This might be off by one due to a race that we can't
+	 * really prevent here without synchronize_net() which
+	 * can't be called now.
+	 */
+	start_seq_num = sta->tid_seq[tid] >> 4;
+
+	ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
+			       &sta->sta, tid, &start_seq_num);
+	if (ret) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+		printk(KERN_DEBUG "BA request denied - HW unavailable for"
+					" tid %d\n", tid);
+#endif
+		rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
+		ieee80211_wake_queue_agg(local, tid);
+		call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
+		return;
+	}
+
+	/* we can take packets again now */
+	ieee80211_wake_queue_agg(local, tid);
+
+	/* activate the timer for the recipient's addBA response */
+	mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
+#ifdef CONFIG_MAC80211_HT_DEBUG
+	printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
+#endif
+
+	sta->ampdu_mlme.addba_req_num[tid]++;
+
+	/* send AddBA request */
+	ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
+				     tid_tx->dialog_token, start_seq_num,
+				     0x40, 5000);
+}
+
+void ieee80211_tx_ba_session_work(struct work_struct *work)
+{
+	struct sta_info *sta =
+		container_of(work, struct sta_info, ampdu_mlme.work);
+	struct tid_ampdu_tx *tid_tx;
+	int tid;
+
+	/*
+	 * When this flag is set, new sessions should be
+	 * blocked, and existing sessions will be torn
+	 * down by the code that set the flag, so this
+	 * need not run.
+	 */
+	if (test_sta_flags(sta, WLAN_STA_BLOCK_BA))
+		return;
+
+	spin_lock_bh(&sta->lock);
+	for (tid = 0; tid < STA_TID_NUM; tid++) {
+		tid_tx = sta->ampdu_mlme.tid_tx[tid];
+		if (!tid_tx)
+			continue;
+
+		if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state))
+			ieee80211_tx_ba_session_handle_start(sta, tid);
+		else if (test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
+					    &tid_tx->state))
+			___ieee80211_stop_tx_ba_session(sta, tid,
+							WLAN_BACK_INITIATOR);
+	}
+	spin_unlock_bh(&sta->lock);
+}
+
 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 {
 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
@@ -262,7 +357,6 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 	struct ieee80211_local *local = sdata->local;
 	struct tid_ampdu_tx *tid_tx;
 	int ret = 0;
-	u16 start_seq_num;
 
 	trace_api_start_tx_ba_session(pubsta, tid);
 
@@ -316,15 +410,6 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 		goto err_unlock_sta;
 	}
 
-	/*
-	 * While we're asking the driver about the aggregation,
-	 * stop the AC queue so that we don't have to worry
-	 * about frames that came in while we were doing that,
-	 * which would require us to put them to the AC pending
-	 * afterwards which just makes the code more complex.
-	 */
-	ieee80211_stop_queue_agg(local, tid);
-
 	/* prepare A-MPDU MLME for Tx aggregation */
 	tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 	if (!tid_tx) {
@@ -334,59 +419,27 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 					tid);
 #endif
 		ret = -ENOMEM;
-		goto err_wake_queue;
+		goto err_unlock_sta;
 	}
 
 	skb_queue_head_init(&tid_tx->pending);
+	__set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
 
 	/* Tx timer */
 	tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired;
 	tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 	init_timer(&tid_tx->addba_resp_timer);
 
-	start_seq_num = sta->tid_seq[tid] >> 4;
-
-	ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
-			       pubsta, tid, &start_seq_num);
-	if (ret) {
-#ifdef CONFIG_MAC80211_HT_DEBUG
-		printk(KERN_DEBUG "BA request denied - HW unavailable for"
-					" tid %d\n", tid);
-#endif /* CONFIG_MAC80211_HT_DEBUG */
-		goto err_free;
-	}
-
-	rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
-
-	/* Driver vetoed or OKed, but we can take packets again now */
-	ieee80211_wake_queue_agg(local, tid);
-
-	/* activate the timer for the recipient's addBA response */
-	tid_tx->addba_resp_timer.expires = jiffies + ADDBA_RESP_INTERVAL;
-	add_timer(&tid_tx->addba_resp_timer);
-#ifdef CONFIG_MAC80211_HT_DEBUG
-	printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
-#endif
-
-	/* prepare tid data */
+	/* assign a dialog token */
 	sta->ampdu_mlme.dialog_token_allocator++;
 	tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
-	tid_tx->ssn = start_seq_num;
-
-	sta->ampdu_mlme.addba_req_num[tid]++;
 
-	spin_unlock_bh(&sta->lock);
+	/* finally, assign it to the array */
+	rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
 
-	/* send AddBA request */
-	ieee80211_send_addba_request(sdata, pubsta->addr, tid,
-			 tid_tx->dialog_token, tid_tx->ssn,
-			 0x40, 5000);
-	return 0;
+	ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 
- err_free:
-	kfree(tid_tx);
- err_wake_queue:
-	ieee80211_wake_queue_agg(local, tid);
+	/* this flow continues off the work */
  err_unlock_sta:
 	spin_unlock_bh(&sta->lock);
 	return ret;
@@ -534,8 +587,7 @@ int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 	spin_lock_bh(&sta->lock);
 	tid_tx = sta->ampdu_mlme.tid_tx[tid];
 
-	/* check if the TID is in aggregation */
-	if (!tid_tx || !test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
+	if (!tid_tx) {
 		ret = -ENOENT;
 		goto unlock;
 	}
@@ -552,6 +604,8 @@ int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 	struct ieee80211_sub_if_data *sdata = sta->sdata;
 	struct ieee80211_local *local = sdata->local;
+	struct tid_ampdu_tx *tid_tx;
+	int ret = 0;
 
 	trace_api_stop_tx_ba_session(pubsta, tid);
 
@@ -561,7 +615,26 @@ int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 	if (tid >= STA_TID_NUM)
 		return -EINVAL;
 
-	return __ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
+	spin_lock_bh(&sta->lock);
+	tid_tx = sta->ampdu_mlme.tid_tx[tid];
+
+	if (!tid_tx) {
+		ret = -ENOENT;
+		goto unlock;
+	}
+
+	if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
+		/* already in progress stopping it */
+		ret = 0;
+		goto unlock;
+	}
+
+	set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state);
+	ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
+
+ unlock:
+	spin_unlock_bh(&sta->lock);
+	return ret;
 }
 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
 
diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c
index 8a74ffb36ad..76839d4dfaa 100644
--- a/net/mac80211/debugfs_sta.c
+++ b/net/mac80211/debugfs_sta.c
@@ -121,7 +121,7 @@ static ssize_t sta_agg_status_read(struct file *file, char __user *userbuf,
 	p += scnprintf(p, sizeof(buf) + buf - p, "next dialog_token: %#02x\n",
 			sta->ampdu_mlme.dialog_token_allocator + 1);
 	p += scnprintf(p, sizeof(buf) + buf - p,
-		       "TID\t\tRX active\tDTKN\tSSN\t\tTX\tDTKN\tSSN\tpending\n");
+		       "TID\t\tRX active\tDTKN\tSSN\t\tTX\tDTKN\tpending\n");
 	for (i = 0; i < STA_TID_NUM; i++) {
 		p += scnprintf(p, sizeof(buf) + buf - p, "%02d", i);
 		p += scnprintf(p, sizeof(buf) + buf - p, "\t\t%x",
@@ -138,9 +138,6 @@ static ssize_t sta_agg_status_read(struct file *file, char __user *userbuf,
 		p += scnprintf(p, sizeof(buf) + buf - p, "\t%#.2x",
 				sta->ampdu_mlme.tid_tx[i] ?
 				sta->ampdu_mlme.tid_tx[i]->dialog_token : 0);
-		p += scnprintf(p, sizeof(buf) + buf - p, "\t%#.3x",
-				sta->ampdu_mlme.tid_tx[i] ?
-				sta->ampdu_mlme.tid_tx[i]->ssn : 0);
 		p += scnprintf(p, sizeof(buf) + buf - p, "\t%03d",
 				sta->ampdu_mlme.tid_tx[i] ?
 				skb_queue_len(&sta->ampdu_mlme.tid_tx[i]->pending) : 0);
diff --git a/net/mac80211/ht.c b/net/mac80211/ht.c
index 1af173ed2d5..4dfba7808a2 100644
--- a/net/mac80211/ht.c
+++ b/net/mac80211/ht.c
@@ -105,6 +105,8 @@ void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta)
 {
 	int i;
 
+	cancel_work_sync(&sta->ampdu_mlme.work);
+
 	for (i = 0; i <  STA_TID_NUM; i++) {
 		__ieee80211_stop_tx_ba_session(sta, i, WLAN_BACK_INITIATOR);
 		__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 8a91b5d8387..aec84c36c4c 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1115,6 +1115,7 @@ int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 				   enum ieee80211_back_parties initiator);
 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid);
 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid);
+void ieee80211_tx_ba_session_work(struct work_struct *work);
 
 /* Spectrum management */
 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 06d8e00a253..8aa8558ba21 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -235,6 +235,7 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
 	spin_lock_init(&sta->lock);
 	spin_lock_init(&sta->flaglock);
 	INIT_WORK(&sta->drv_unblock_wk, sta_unblock);
+	INIT_WORK(&sta->ampdu_mlme.work, ieee80211_tx_ba_session_work);
 
 	memcpy(sta->sta.addr, addr, ETH_ALEN);
 	sta->local = local;
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 05278e6288c..040cbb0ac3a 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -67,6 +67,8 @@ enum ieee80211_sta_info_flags {
 #define HT_AGG_STATE_RESPONSE_RECEIVED	1
 #define HT_AGG_STATE_OPERATIONAL	2
 #define HT_AGG_STATE_STOPPING		3
+#define HT_AGG_STATE_WANT_START		4
+#define HT_AGG_STATE_WANT_STOP		5
 
 /**
  * struct tid_ampdu_tx - TID aggregation information (Tx).
@@ -74,7 +76,6 @@ enum ieee80211_sta_info_flags {
  * @rcu_head: rcu head for freeing structure
  * @addba_resp_timer: timer for peer's response to addba request
  * @pending: pending frames queue -- use sta's spinlock to protect
- * @ssn: Starting Sequence Number expected to be aggregated.
  * @dialog_token: dialog token for aggregation session
  * @state: session state (see above)
  * @stop_initiator: initiator of a session stop
@@ -92,7 +93,6 @@ struct tid_ampdu_tx {
 	struct timer_list addba_resp_timer;
 	struct sk_buff_head pending;
 	unsigned long state;
-	u16 ssn;
 	u8 dialog_token;
 	u8 stop_initiator;
 };
@@ -139,11 +139,13 @@ struct tid_ampdu_rx {
  * @tid_tx: aggregation info for Tx per TID
  * @addba_req_num: number of times addBA request has been sent.
  * @dialog_token_allocator: dialog token enumerator for each new session;
+ * @work: work struct for starting/stopping aggregation
  */
 struct sta_ampdu_mlme {
 	/* rx */
 	struct tid_ampdu_rx *tid_rx[STA_TID_NUM];
 	/* tx */
+	struct work_struct work;
 	struct tid_ampdu_tx *tid_tx[STA_TID_NUM];
 	u8 addba_req_num[STA_TID_NUM];
 	u8 dialog_token_allocator;
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 7bf1f9c9ea3..698d4718b1a 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1102,6 +1102,11 @@ static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
 
 	if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
 		info->flags |= IEEE80211_TX_CTL_AMPDU;
+	} else if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
+		/*
+		 * nothing -- this aggregation session is being started
+		 * but that might still fail with the driver
+		 */
 	} else {
 		spin_lock(&tx->sta->lock);
 		/*
-- 
cgit v1.2.3-70-g09d2


From 67c282c00c9c06733aae229662d209957f6d23a7 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Thu, 10 Jun 2010 10:21:43 +0200
Subject: mac80211: move BA session work

Move the block-ack session works into common
code, since it will be needed for RX agg too
in the next patches.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
 net/mac80211/agg-tx.c      | 39 +++------------------------------------
 net/mac80211/ht.c          | 32 ++++++++++++++++++++++++++++++++
 net/mac80211/ieee80211_i.h |  5 ++++-
 net/mac80211/sta_info.c    |  2 +-
 4 files changed, 40 insertions(+), 38 deletions(-)

(limited to 'net/mac80211/sta_info.c')

diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index ee8bfe18b48..9a00a79a868 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -133,9 +133,8 @@ static void kfree_tid_tx(struct rcu_head *rcu_head)
 	kfree(tid_tx);
 }
 
-static int ___ieee80211_stop_tx_ba_session(
-		struct sta_info *sta, u16 tid,
-		enum ieee80211_back_parties initiator)
+int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
+				    enum ieee80211_back_parties initiator)
 {
 	struct ieee80211_local *local = sta->local;
 	struct tid_ampdu_tx *tid_tx = sta->ampdu_mlme.tid_tx[tid];
@@ -262,7 +261,7 @@ ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid)
 	__release(agg_queue);
 }
 
-static void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
+void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 {
 	struct tid_ampdu_tx *tid_tx = sta->ampdu_mlme.tid_tx[tid];
 	struct ieee80211_local *local = sta->local;
@@ -318,38 +317,6 @@ static void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 				     0x40, 5000);
 }
 
-void ieee80211_tx_ba_session_work(struct work_struct *work)
-{
-	struct sta_info *sta =
-		container_of(work, struct sta_info, ampdu_mlme.work);
-	struct tid_ampdu_tx *tid_tx;
-	int tid;
-
-	/*
-	 * When this flag is set, new sessions should be
-	 * blocked, and existing sessions will be torn
-	 * down by the code that set the flag, so this
-	 * need not run.
-	 */
-	if (test_sta_flags(sta, WLAN_STA_BLOCK_BA))
-		return;
-
-	spin_lock_bh(&sta->lock);
-	for (tid = 0; tid < STA_TID_NUM; tid++) {
-		tid_tx = sta->ampdu_mlme.tid_tx[tid];
-		if (!tid_tx)
-			continue;
-
-		if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state))
-			ieee80211_tx_ba_session_handle_start(sta, tid);
-		else if (test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
-					    &tid_tx->state))
-			___ieee80211_stop_tx_ba_session(sta, tid,
-							WLAN_BACK_INITIATOR);
-	}
-	spin_unlock_bh(&sta->lock);
-}
-
 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 {
 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
diff --git a/net/mac80211/ht.c b/net/mac80211/ht.c
index 4dfba7808a2..531a19d358d 100644
--- a/net/mac80211/ht.c
+++ b/net/mac80211/ht.c
@@ -114,6 +114,38 @@ void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta)
 	}
 }
 
+void ieee80211_ba_session_work(struct work_struct *work)
+{
+	struct sta_info *sta =
+		container_of(work, struct sta_info, ampdu_mlme.work);
+	struct tid_ampdu_tx *tid_tx;
+	int tid;
+
+	/*
+	 * When this flag is set, new sessions should be
+	 * blocked, and existing sessions will be torn
+	 * down by the code that set the flag, so this
+	 * need not run.
+	 */
+	if (test_sta_flags(sta, WLAN_STA_BLOCK_BA))
+		return;
+
+	spin_lock_bh(&sta->lock);
+	for (tid = 0; tid < STA_TID_NUM; tid++) {
+		tid_tx = sta->ampdu_mlme.tid_tx[tid];
+		if (!tid_tx)
+			continue;
+
+		if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state))
+			ieee80211_tx_ba_session_handle_start(sta, tid);
+		else if (test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
+					    &tid_tx->state))
+			___ieee80211_stop_tx_ba_session(sta, tid,
+							WLAN_BACK_INITIATOR);
+	}
+	spin_unlock_bh(&sta->lock);
+}
+
 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
 			  const u8 *da, u16 tid,
 			  u16 initiator, u16 reason_code)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index aec84c36c4c..628a53db9f7 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1113,9 +1113,12 @@ void ieee80211_process_addba_request(struct ieee80211_local *local,
 
 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 				   enum ieee80211_back_parties initiator);
+int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
+				    enum ieee80211_back_parties initiator);
 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid);
 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid);
-void ieee80211_tx_ba_session_work(struct work_struct *work);
+void ieee80211_ba_session_work(struct work_struct *work);
+void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid);
 
 /* Spectrum management */
 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 8aa8558ba21..bd726c6204d 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -235,7 +235,7 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
 	spin_lock_init(&sta->lock);
 	spin_lock_init(&sta->flaglock);
 	INIT_WORK(&sta->drv_unblock_wk, sta_unblock);
-	INIT_WORK(&sta->ampdu_mlme.work, ieee80211_tx_ba_session_work);
+	INIT_WORK(&sta->ampdu_mlme.work, ieee80211_ba_session_work);
 
 	memcpy(sta->sta.addr, addr, ETH_ALEN);
 	sta->local = local;
-- 
cgit v1.2.3-70-g09d2


From a93e364430de7f7a5f4eedd604ad1ab3d825dde5 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Thu, 10 Jun 2010 10:21:46 +0200
Subject: mac80211: change RX aggregation locking

To prepare for allowing drivers to sleep in
ampdu_action, change the locking in the RX
aggregation code to use a mutex, so that it
would already allow drivers to sleep. But
explicitly disable BHs around the callback
for now since the TX part cannot yet sleep,
and drivers' locking might require it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
 net/mac80211/agg-rx.c     | 12 ++++++------
 net/mac80211/driver-ops.h |  2 ++
 net/mac80211/ht.c         |  6 +++++-
 net/mac80211/iface.c      |  8 ++++----
 net/mac80211/sta_info.c   |  1 +
 net/mac80211/sta_info.h   |  3 +++
 6 files changed, 21 insertions(+), 11 deletions(-)

(limited to 'net/mac80211/sta_info.c')

diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
index aa858a03951..a843df26f38 100644
--- a/net/mac80211/agg-rx.c
+++ b/net/mac80211/agg-rx.c
@@ -6,7 +6,7 @@
  * Copyright 2005-2006, Devicescape Software, Inc.
  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
- * Copyright 2007-2008, Intel Corporation
+ * Copyright 2007-2010, Intel Corporation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -38,7 +38,7 @@ void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
 	struct ieee80211_local *local = sta->local;
 	struct tid_ampdu_rx *tid_rx;
 
-	lockdep_assert_held(&sta->lock);
+	lockdep_assert_held(&sta->ampdu_mlme.mtx);
 
 	tid_rx = sta->ampdu_mlme.tid_rx[tid];
 
@@ -70,9 +70,9 @@ void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
 				    u16 initiator, u16 reason)
 {
-	spin_lock_bh(&sta->lock);
+	mutex_lock(&sta->ampdu_mlme.mtx);
 	___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason);
-	spin_unlock_bh(&sta->lock);
+	mutex_unlock(&sta->ampdu_mlme.mtx);
 }
 
 /*
@@ -205,7 +205,7 @@ void ieee80211_process_addba_request(struct ieee80211_local *local,
 
 
 	/* examine state machine */
-	spin_lock_bh(&sta->lock);
+	mutex_lock(&sta->ampdu_mlme.mtx);
 
 	if (sta->ampdu_mlme.tid_rx[tid]) {
 #ifdef CONFIG_MAC80211_HT_DEBUG
@@ -279,7 +279,7 @@ void ieee80211_process_addba_request(struct ieee80211_local *local,
 		mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
 
 end:
-	spin_unlock_bh(&sta->lock);
+	mutex_unlock(&sta->ampdu_mlme.mtx);
 
 end_no_lock:
 	ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index 7d18a3245e3..e5e7ef175ca 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -349,9 +349,11 @@ static inline int drv_ampdu_action(struct ieee80211_local *local,
 				   u16 *ssn)
 {
 	int ret = -EOPNOTSUPP;
+	local_bh_disable();
 	if (local->ops->ampdu_action)
 		ret = local->ops->ampdu_action(&local->hw, &sdata->vif, action,
 					       sta, tid, ssn);
+	local_bh_enable();
 	trace_drv_ampdu_action(local, sdata, action, sta, tid, ssn, ret);
 	return ret;
 }
diff --git a/net/mac80211/ht.c b/net/mac80211/ht.c
index 730f8089678..e29be64083c 100644
--- a/net/mac80211/ht.c
+++ b/net/mac80211/ht.c
@@ -130,13 +130,17 @@ void ieee80211_ba_session_work(struct work_struct *work)
 	if (test_sta_flags(sta, WLAN_STA_BLOCK_BA))
 		return;
 
-	spin_lock_bh(&sta->lock);
+	mutex_lock(&sta->ampdu_mlme.mtx);
 	for (tid = 0; tid < STA_TID_NUM; tid++) {
 		if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
 			___ieee80211_stop_rx_ba_session(
 				sta, tid, WLAN_BACK_RECIPIENT,
 				WLAN_REASON_QSTA_TIMEOUT);
+	}
+	mutex_unlock(&sta->ampdu_mlme.mtx);
 
+	spin_lock_bh(&sta->lock);
+	for (tid = 0; tid < STA_TID_NUM; tid++) {
 		tid_tx = sta->ampdu_mlme.tid_tx[tid];
 		if (!tid_tx)
 			continue;
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 9f00d3f174e..490be2f3af2 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -740,7 +740,7 @@ static void ieee80211_iface_work(struct work_struct *work)
 			   mgmt->u.action.category == WLAN_CATEGORY_BACK) {
 			int len = skb->len;
 
-			rcu_read_lock();
+			mutex_lock(&local->sta_mtx);
 			sta = sta_info_get(sdata, mgmt->sa);
 			if (sta) {
 				switch (mgmt->u.action.u.addba_req.action_code) {
@@ -761,7 +761,7 @@ static void ieee80211_iface_work(struct work_struct *work)
 					break;
 				}
 			}
-			rcu_read_unlock();
+			mutex_unlock(&local->sta_mtx);
 		} else if (ieee80211_is_data_qos(mgmt->frame_control)) {
 			struct ieee80211_hdr *hdr = (void *)mgmt;
 			/*
@@ -781,7 +781,7 @@ static void ieee80211_iface_work(struct work_struct *work)
 			 * a block-ack session was active. That cannot be
 			 * right, so terminate the session.
 			 */
-			rcu_read_lock();
+			mutex_lock(&local->sta_mtx);
 			sta = sta_info_get(sdata, mgmt->sa);
 			if (sta) {
 				u16 tid = *ieee80211_get_qos_ctl(hdr) &
@@ -791,7 +791,7 @@ static void ieee80211_iface_work(struct work_struct *work)
 					sta, tid, WLAN_BACK_RECIPIENT,
 					WLAN_REASON_QSTA_REQUIRE_SETUP);
 			}
-			rcu_read_unlock();
+			mutex_unlock(&local->sta_mtx);
 		} else switch (sdata->vif.type) {
 		case NL80211_IFTYPE_STATION:
 			ieee80211_sta_rx_queued_mgmt(sdata, skb);
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index bd726c6204d..f54d8ba7d78 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -236,6 +236,7 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
 	spin_lock_init(&sta->flaglock);
 	INIT_WORK(&sta->drv_unblock_wk, sta_unblock);
 	INIT_WORK(&sta->ampdu_mlme.work, ieee80211_ba_session_work);
+	mutex_init(&sta->ampdu_mlme.mtx);
 
 	memcpy(sta->sta.addr, addr, ETH_ALEN);
 	sta->local = local;
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 500bafe0a0b..10d0fcb417a 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -142,8 +142,11 @@ struct tid_ampdu_rx {
  * @work: work struct for starting/stopping aggregation
  * @tid_rx_timer_expired: bitmap indicating on which TIDs the
  *	RX timer expired until the work for it runs
+ * @mtx: mutex to protect all TX data (except non-NULL assignments
+ *	to tid_tx[idx], which are protected by the sta spinlock)
  */
 struct sta_ampdu_mlme {
+	struct mutex mtx;
 	/* rx */
 	struct tid_ampdu_rx *tid_rx[STA_TID_NUM];
 	unsigned long tid_rx_timer_expired[BITS_TO_LONGS(STA_TID_NUM)];
-- 
cgit v1.2.3-70-g09d2