ieee80211_tx_skb(sdata, skb);
}
-int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
- enum ieee80211_back_parties initiator)
+static void kfree_tid_tx(struct rcu_head *rcu_head)
+{
+ struct tid_ampdu_tx *tid_tx =
+ container_of(rcu_head, struct tid_ampdu_tx, rcu_head);
+
+ kfree(tid_tx);
+}
+
+static 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];
int ret;
- u8 *state;
+
+ lockdep_assert_held(&sta->lock);
+
+ if (WARN_ON(!tid_tx))
+ return -ENOENT;
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
sta->sta.addr, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
- state = &sta->ampdu_mlme.tid_state_tx[tid];
+ set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
- if (*state == HT_AGG_STATE_OPERATIONAL)
- sta->ampdu_mlme.addba_req_num[tid] = 0;
+ /*
+ * After this packets are no longer handed right through
+ * to the driver but are put onto tid_tx->pending instead,
+ * with locking to ensure proper access.
+ */
+ clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
- *state = HT_AGG_STATE_REQ_STOP_BA_MSK |
- (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
+ tid_tx->stop_initiator = initiator;
ret = drv_ampdu_action(local, sta->sdata,
IEEE80211_AMPDU_TX_STOP,
u16 tid = *(u8 *)data;
struct sta_info *sta = container_of((void *)data,
struct sta_info, timer_to_tid[tid]);
- u8 *state;
-
- state = &sta->ampdu_mlme.tid_state_tx[tid];
+ struct tid_ampdu_tx *tid_tx;
/* check if the TID waits for addBA response */
spin_lock_bh(&sta->lock);
- if ((*state & (HT_ADDBA_REQUESTED_MSK | HT_ADDBA_RECEIVED_MSK |
- HT_AGG_STATE_REQ_STOP_BA_MSK)) !=
- HT_ADDBA_REQUESTED_MSK) {
+ tid_tx = sta->ampdu_mlme.tid_tx[tid];
+ if (!tid_tx ||
+ test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
spin_unlock_bh(&sta->lock);
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "timer expired on tid %d but we are not "
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;
- u8 *state;
+ struct tid_ampdu_tx *tid_tx;
int ret = 0;
u16 start_seq_num;
goto err_unlock_sta;
}
- state = &sta->ampdu_mlme.tid_state_tx[tid];
+ tid_tx = sta->ampdu_mlme.tid_tx[tid];
/* check if the TID is not in aggregation flow already */
- if (*state != HT_AGG_STATE_IDLE) {
+ if (tid_tx) {
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "BA request denied - session is not "
"idle on tid %u\n", tid);
IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
/* prepare A-MPDU MLME for Tx aggregation */
- sta->ampdu_mlme.tid_tx[tid] =
- kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
- if (!sta->ampdu_mlme.tid_tx[tid]) {
+ tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
+ if (!tid_tx) {
#ifdef CONFIG_MAC80211_HT_DEBUG
if (net_ratelimit())
printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
goto err_wake_queue;
}
- skb_queue_head_init(&sta->ampdu_mlme.tid_tx[tid]->pending);
+ skb_queue_head_init(&tid_tx->pending);
/* Tx timer */
- sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
- sta_addba_resp_timer_expired;
- sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
- (unsigned long)&sta->timer_to_tid[tid];
- init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
-
- /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
- * call back right away, it must see that the flow has begun */
- *state |= HT_ADDBA_REQUESTED_MSK;
+ 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 */
- *state = HT_AGG_STATE_IDLE;
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_by_reason(
&local->hw, ieee80211_ac_from_tid(tid),
spin_unlock(&local->ampdu_lock);
+ /* 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 */
sta->ampdu_mlme.dialog_token_allocator++;
- sta->ampdu_mlme.tid_tx[tid]->dialog_token =
- sta->ampdu_mlme.dialog_token_allocator;
- sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
+ 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);
/* send AddBA request */
ieee80211_send_addba_request(sdata, pubsta->addr, tid,
- sta->ampdu_mlme.tid_tx[tid]->dialog_token,
- sta->ampdu_mlme.tid_tx[tid]->ssn,
+ tid_tx->dialog_token, tid_tx->ssn,
0x40, 5000);
- sta->ampdu_mlme.addba_req_num[tid]++;
- /* activate the timer for the recipient's addBA response */
- sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
- jiffies + ADDBA_RESP_INTERVAL;
- add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
-#ifdef CONFIG_MAC80211_HT_DEBUG
- printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
-#endif
return 0;
err_free:
- kfree(sta->ampdu_mlme.tid_tx[tid]);
- sta->ampdu_mlme.tid_tx[tid] = NULL;
+ kfree(tid_tx);
err_wake_queue:
ieee80211_wake_queue_by_reason(
&local->hw, ieee80211_ac_from_tid(tid),
* local->ampdu_lock across both calls.
*/
static void ieee80211_agg_splice_packets(struct ieee80211_local *local,
- struct sta_info *sta, u16 tid)
+ struct tid_ampdu_tx *tid_tx,
+ u16 tid)
{
unsigned long flags;
u16 queue = ieee80211_ac_from_tid(tid);
&local->hw, queue,
IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
- if (!(sta->ampdu_mlme.tid_state_tx[tid] & HT_ADDBA_REQUESTED_MSK))
- return;
-
- if (WARN(!sta->ampdu_mlme.tid_tx[tid],
- "TID %d gone but expected when splicing aggregates from"
- "the pending queue\n", tid))
+ if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates"
+ " from the pending queue\n", tid))
return;
- if (!skb_queue_empty(&sta->ampdu_mlme.tid_tx[tid]->pending)) {
+ if (!skb_queue_empty(&tid_tx->pending)) {
spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
/* copy over remaining packets */
- skb_queue_splice_tail_init(
- &sta->ampdu_mlme.tid_tx[tid]->pending,
- &local->pending[queue]);
+ skb_queue_splice_tail_init(&tid_tx->pending,
+ &local->pending[queue]);
spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
}
}
-static void ieee80211_agg_splice_finish(struct ieee80211_local *local,
- struct sta_info *sta, u16 tid)
+static void ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid)
{
- u16 queue = ieee80211_ac_from_tid(tid);
-
ieee80211_wake_queue_by_reason(
- &local->hw, queue,
+ &local->hw, ieee80211_ac_from_tid(tid),
IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
}
static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
struct sta_info *sta, u16 tid)
{
+ lockdep_assert_held(&sta->lock);
+
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid);
#endif
spin_lock(&local->ampdu_lock);
- ieee80211_agg_splice_packets(local, sta, tid);
+ ieee80211_agg_splice_packets(local, sta->ampdu_mlme.tid_tx[tid], tid);
/*
- * NB: we rely on sta->lock being taken in the TX
- * processing here when adding to the pending queue,
- * otherwise we could only change the state of the
- * session to OPERATIONAL _here_.
+ * Now mark as operational. This will be visible
+ * in the TX path, and lets it go lock-free in
+ * the common case.
*/
- ieee80211_agg_splice_finish(local, sta, tid);
+ set_bit(HT_AGG_STATE_OPERATIONAL, &sta->ampdu_mlme.tid_tx[tid]->state);
+ ieee80211_agg_splice_finish(local, tid);
spin_unlock(&local->ampdu_lock);
drv_ampdu_action(local, sta->sdata,
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
- u8 *state;
+ struct tid_ampdu_tx *tid_tx;
trace_api_start_tx_ba_cb(sdata, ra, tid);
return;
}
- state = &sta->ampdu_mlme.tid_state_tx[tid];
spin_lock_bh(&sta->lock);
+ tid_tx = sta->ampdu_mlme.tid_tx[tid];
- if (WARN_ON(!(*state & HT_ADDBA_REQUESTED_MSK))) {
+ if (WARN_ON(!tid_tx)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
- printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
- *state);
+ printk(KERN_DEBUG "addBA was not requested!\n");
#endif
spin_unlock_bh(&sta->lock);
rcu_read_unlock();
return;
}
- if (WARN_ON(*state & HT_ADDBA_DRV_READY_MSK))
+ if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
goto out;
- *state |= HT_ADDBA_DRV_READY_MSK;
-
- if (*state == HT_AGG_STATE_OPERATIONAL)
+ if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
ieee80211_agg_tx_operational(local, sta, tid);
out:
int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
enum ieee80211_back_parties initiator)
{
- u8 *state;
+ struct tid_ampdu_tx *tid_tx;
int ret;
- /* check if the TID is in aggregation */
- state = &sta->ampdu_mlme.tid_state_tx[tid];
spin_lock_bh(&sta->lock);
+ tid_tx = sta->ampdu_mlme.tid_tx[tid];
- if (*state != HT_AGG_STATE_OPERATIONAL) {
+ /* check if the TID is in aggregation */
+ if (!tid_tx || !test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
ret = -ENOENT;
goto unlock;
}
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
- u8 *state;
+ struct tid_ampdu_tx *tid_tx;
trace_api_stop_tx_ba_cb(sdata, ra, tid);
rcu_read_unlock();
return;
}
- state = &sta->ampdu_mlme.tid_state_tx[tid];
- /* NOTE: no need to use sta->lock in this state check, as
- * ieee80211_stop_tx_ba_session will let only one stop call to
- * pass through per sta/tid
- */
- if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
+ spin_lock_bh(&sta->lock);
+ tid_tx = sta->ampdu_mlme.tid_tx[tid];
+
+ if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
#endif
+ spin_unlock_bh(&sta->lock);
rcu_read_unlock();
return;
}
- if (*state & HT_AGG_STATE_INITIATOR_MSK)
+ if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR)
ieee80211_send_delba(sta->sdata, ra, tid,
WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
- spin_lock_bh(&sta->lock);
- spin_lock(&local->ampdu_lock);
+ /*
+ * When we get here, the TX path will not be lockless any more wrt.
+ * aggregation, since the OPERATIONAL bit has long been cleared.
+ * Thus it will block on getting the lock, if it occurs. So if we
+ * stop the queue now, we will not get any more packets, and any
+ * that might be being processed will wait for us here, thereby
+ * guaranteeing that no packets go to the tid_tx pending queue any
+ * more.
+ */
- ieee80211_agg_splice_packets(local, sta, tid);
+ spin_lock(&local->ampdu_lock);
+ ieee80211_agg_splice_packets(local, tid_tx, tid);
- *state = HT_AGG_STATE_IDLE;
- /* from now on packets are no longer put onto sta->pending */
- kfree(sta->ampdu_mlme.tid_tx[tid]);
- sta->ampdu_mlme.tid_tx[tid] = NULL;
+ /* future packets must not find the tid_tx struct any more */
+ rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
- ieee80211_agg_splice_finish(local, sta, tid);
+ ieee80211_agg_splice_finish(local, tid);
+ call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
spin_unlock(&local->ampdu_lock);
- spin_unlock_bh(&sta->lock);
+ spin_unlock_bh(&sta->lock);
rcu_read_unlock();
}
EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
struct ieee80211_mgmt *mgmt,
size_t len)
{
+ struct tid_ampdu_tx *tid_tx;
u16 capab, tid;
- u8 *state;
capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
- state = &sta->ampdu_mlme.tid_state_tx[tid];
-
spin_lock_bh(&sta->lock);
- if (!(*state & HT_ADDBA_REQUESTED_MSK))
+ tid_tx = sta->ampdu_mlme.tid_tx[tid];
+
+ if (!tid_tx)
goto out;
- if (mgmt->u.action.u.addba_resp.dialog_token !=
- sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
+ if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
-#endif /* CONFIG_MAC80211_HT_DEBUG */
+#endif
goto out;
}
- del_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
+ del_timer(&tid_tx->addba_resp_timer);
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid);
-#endif /* CONFIG_MAC80211_HT_DEBUG */
+#endif
if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
== WLAN_STATUS_SUCCESS) {
- u8 curstate = *state;
-
- *state |= HT_ADDBA_RECEIVED_MSK;
+ if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
+ &tid_tx->state)) {
+ /* ignore duplicate response */
+ goto out;
+ }
- if (*state != curstate && *state == HT_AGG_STATE_OPERATIONAL)
+ if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
ieee80211_agg_tx_operational(local, sta, tid);
sta->ampdu_mlme.addba_req_num[tid] = 0;
return true;
}
+static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
+ struct sk_buff *skb,
+ struct ieee80211_tx_info *info,
+ struct tid_ampdu_tx *tid_tx,
+ int tid)
+{
+ bool queued = false;
+
+ if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
+ info->flags |= IEEE80211_TX_CTL_AMPDU;
+ } else {
+ spin_lock(&tx->sta->lock);
+ /*
+ * Need to re-check now, because we may get here
+ *
+ * 1) in the window during which the setup is actually
+ * already done, but not marked yet because not all
+ * packets are spliced over to the driver pending
+ * queue yet -- if this happened we acquire the lock
+ * either before or after the splice happens, but
+ * need to recheck which of these cases happened.
+ *
+ * 2) during session teardown, if the OPERATIONAL bit
+ * was cleared due to the teardown but the pointer
+ * hasn't been assigned NULL yet (or we loaded it
+ * before it was assigned) -- in this case it may
+ * now be NULL which means we should just let the
+ * packet pass through because splicing the frames
+ * back is already done.
+ */
+ tid_tx = tx->sta->ampdu_mlme.tid_tx[tid];
+
+ if (!tid_tx) {
+ /* do nothing, let packet pass through */
+ } else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
+ info->flags |= IEEE80211_TX_CTL_AMPDU;
+ } else {
+ queued = true;
+ info->control.vif = &tx->sdata->vif;
+ info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
+ __skb_queue_tail(&tid_tx->pending, skb);
+ }
+ spin_unlock(&tx->sta->lock);
+ }
+
+ return queued;
+}
+
/*
* initialises @tx
*/
struct ieee80211_hdr *hdr;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
int hdrlen, tid;
- u8 *qc, *state;
- bool queued = false;
+ u8 *qc;
memset(tx, 0, sizeof(*tx));
tx->skb = skb;
qc = ieee80211_get_qos_ctl(hdr);
tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
- spin_lock(&tx->sta->lock);
- /*
- * XXX: This spinlock could be fairly expensive, but see the
- * comment in agg-tx.c:ieee80211_agg_tx_operational().
- * One way to solve this would be to do something RCU-like
- * for managing the tid_tx struct and using atomic bitops
- * for the actual state -- by introducing an actual
- * 'operational' bit that would be possible. It would
- * require changing ieee80211_agg_tx_operational() to
- * set that bit, and changing the way tid_tx is managed
- * everywhere, including races between that bit and
- * tid_tx going away (tid_tx being added can be easily
- * committed to memory before the 'operational' bit).
- */
- tid_tx = tx->sta->ampdu_mlme.tid_tx[tid];
- state = &tx->sta->ampdu_mlme.tid_state_tx[tid];
- if (*state == HT_AGG_STATE_OPERATIONAL) {
- info->flags |= IEEE80211_TX_CTL_AMPDU;
- } else if (*state != HT_AGG_STATE_IDLE) {
- /* in progress */
- queued = true;
- info->control.vif = &sdata->vif;
- info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
- __skb_queue_tail(&tid_tx->pending, skb);
- }
- spin_unlock(&tx->sta->lock);
+ tid_tx = rcu_dereference(tx->sta->ampdu_mlme.tid_tx[tid]);
+ if (tid_tx) {
+ bool queued;
- if (unlikely(queued))
- return TX_QUEUED;
+ queued = ieee80211_tx_prep_agg(tx, skb, info,
+ tid_tx, tid);
+
+ if (unlikely(queued))
+ return TX_QUEUED;
+ }
}
if (is_multicast_ether_addr(hdr->addr1)) {
projects / platform / kernel / linux-stable.git / commitdiff