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authorroot <root@artemis.panaceas.org>2015-12-25 15:00:15 +0000
committerroot <root@artemis.panaceas.org>2015-12-25 15:00:15 +0000
commitddd86436f4e3643c04b797f858dab95d5f2e4de9 (patch)
treebfe7a780cf9a2f4fc33aec32c82e625e79dece1f /net/mac80211/agg-tx.c
downloadbackports-3.10.19-1-master.tar.gz
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Diffstat (limited to 'net/mac80211/agg-tx.c')
-rw-r--r--net/mac80211/agg-tx.c931
1 files changed, 931 insertions, 0 deletions
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
new file mode 100644
index 0000000..13b7683
--- /dev/null
+++ b/net/mac80211/agg-tx.c
@@ -0,0 +1,931 @@
+/*
+ * HT handling
+ *
+ * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
+ * Copyright 2002-2005, Instant802 Networks, Inc.
+ * Copyright 2005-2006, Devicescape Software, Inc.
+ * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
+ * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
+ * 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
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ieee80211.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <net/mac80211.h>
+#include "ieee80211_i.h"
+#include "driver-ops.h"
+#include "wme.h"
+
+/**
+ * DOC: TX A-MPDU aggregation
+ *
+ * Aggregation on the TX side requires setting the hardware flag
+ * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed
+ * packets with a flag indicating A-MPDU aggregation. The driver
+ * or device is responsible for actually aggregating the frames,
+ * as well as deciding how many and which to aggregate.
+ *
+ * When TX aggregation is started by some subsystem (usually the rate
+ * control algorithm would be appropriate) by calling the
+ * ieee80211_start_tx_ba_session() function, the driver will be
+ * notified via its @ampdu_action function, with the
+ * %IEEE80211_AMPDU_TX_START action.
+ *
+ * In response to that, the driver is later required to call the
+ * ieee80211_start_tx_ba_cb_irqsafe() function, which will really
+ * start the aggregation session after the peer has also responded.
+ * If the peer responds negatively, the session will be stopped
+ * again right away. Note that it is possible for the aggregation
+ * session to be stopped before the driver has indicated that it
+ * is done setting it up, in which case it must not indicate the
+ * setup completion.
+ *
+ * Also note that, since we also need to wait for a response from
+ * the peer, the driver is notified of the completion of the
+ * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the
+ * @ampdu_action callback.
+ *
+ * Similarly, when the aggregation session is stopped by the peer
+ * or something calling ieee80211_stop_tx_ba_session(), the driver's
+ * @ampdu_action function will be called with the action
+ * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail,
+ * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe().
+ * Note that the sta can get destroyed before the BA tear down is
+ * complete.
+ */
+
+static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
+ const u8 *da, u16 tid,
+ u8 dialog_token, u16 start_seq_num,
+ u16 agg_size, u16 timeout)
+{
+ struct ieee80211_local *local = sdata->local;
+ struct sk_buff *skb;
+ struct ieee80211_mgmt *mgmt;
+ u16 capab;
+
+ skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
+
+ if (!skb)
+ return;
+
+ skb_reserve(skb, local->hw.extra_tx_headroom);
+ mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
+ memset(mgmt, 0, 24);
+ memcpy(mgmt->da, da, ETH_ALEN);
+ memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
+ if (sdata->vif.type == NL80211_IFTYPE_AP ||
+ sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
+ sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
+ memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
+ else if (sdata->vif.type == NL80211_IFTYPE_STATION)
+ memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
+ else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
+ memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
+
+ mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
+ IEEE80211_STYPE_ACTION);
+
+ skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
+
+ mgmt->u.action.category = WLAN_CATEGORY_BACK;
+ mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
+
+ mgmt->u.action.u.addba_req.dialog_token = dialog_token;
+ capab = (u16)(1 << 1); /* bit 1 aggregation policy */
+ capab |= (u16)(tid << 2); /* bit 5:2 TID number */
+ capab |= (u16)(agg_size << 6); /* bit 15:6 max size of aggergation */
+
+ mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
+
+ mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
+ mgmt->u.action.u.addba_req.start_seq_num =
+ cpu_to_le16(start_seq_num << 4);
+
+ ieee80211_tx_skb_tid(sdata, skb, tid);
+}
+
+void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
+{
+ struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+ struct ieee80211_local *local = sdata->local;
+ struct sk_buff *skb;
+ struct ieee80211_bar *bar;
+ u16 bar_control = 0;
+
+ skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
+ if (!skb)
+ return;
+
+ skb_reserve(skb, local->hw.extra_tx_headroom);
+ bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
+ memset(bar, 0, sizeof(*bar));
+ bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
+ IEEE80211_STYPE_BACK_REQ);
+ memcpy(bar->ra, ra, ETH_ALEN);
+ memcpy(bar->ta, sdata->vif.addr, ETH_ALEN);
+ bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
+ bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
+ bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT);
+ bar->control = cpu_to_le16(bar_control);
+ bar->start_seq_num = cpu_to_le16(ssn);
+
+ IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
+ IEEE80211_TX_CTL_REQ_TX_STATUS;
+ ieee80211_tx_skb_tid(sdata, skb, tid);
+}
+EXPORT_SYMBOL(ieee80211_send_bar);
+
+void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
+ struct tid_ampdu_tx *tid_tx)
+{
+ lockdep_assert_held(&sta->ampdu_mlme.mtx);
+ lockdep_assert_held(&sta->lock);
+ rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
+}
+
+static inline int ieee80211_ac_from_tid(int tid)
+{
+ return ieee802_1d_to_ac[tid & 7];
+}
+
+/*
+ * When multiple aggregation sessions on multiple stations
+ * are being created/destroyed simultaneously, we need to
+ * refcount the global queue stop caused by that in order
+ * to not get into a situation where one of the aggregation
+ * setup or teardown re-enables queues before the other is
+ * ready to handle that.
+ *
+ * These two functions take care of this issue by keeping
+ * a global "agg_queue_stop" refcount.
+ */
+static void __acquires(agg_queue)
+ieee80211_stop_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
+{
+ int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
+
+ if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1)
+ ieee80211_stop_queue_by_reason(
+ &sdata->local->hw, queue,
+ IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
+ __acquire(agg_queue);
+}
+
+static void __releases(agg_queue)
+ieee80211_wake_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
+{
+ int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
+
+ if (atomic_dec_return(&sdata->local->agg_queue_stop[queue]) == 0)
+ ieee80211_wake_queue_by_reason(
+ &sdata->local->hw, queue,
+ IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
+ __release(agg_queue);
+}
+
+/*
+ * splice packets from the STA's pending to the local pending,
+ * requires a call to ieee80211_agg_splice_finish later
+ */
+static void __acquires(agg_queue)
+ieee80211_agg_splice_packets(struct ieee80211_sub_if_data *sdata,
+ struct tid_ampdu_tx *tid_tx, u16 tid)
+{
+ struct ieee80211_local *local = sdata->local;
+ int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
+ unsigned long flags;
+
+ ieee80211_stop_queue_agg(sdata, tid);
+
+ if (WARN(!tid_tx,
+ "TID %d gone but expected when splicing aggregates from the pending queue\n",
+ tid))
+ return;
+
+ 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(&tid_tx->pending,
+ &local->pending[queue]);
+ spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
+ }
+}
+
+static void __releases(agg_queue)
+ieee80211_agg_splice_finish(struct ieee80211_sub_if_data *sdata, u16 tid)
+{
+ ieee80211_wake_queue_agg(sdata, tid);
+}
+
+static void ieee80211_remove_tid_tx(struct sta_info *sta, int tid)
+{
+ struct tid_ampdu_tx *tid_tx;
+
+ lockdep_assert_held(&sta->ampdu_mlme.mtx);
+ lockdep_assert_held(&sta->lock);
+
+ tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
+
+ /*
+ * 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(sta->sdata, tid_tx, tid);
+
+ /* future packets must not find the tid_tx struct any more */
+ ieee80211_assign_tid_tx(sta, tid, NULL);
+
+ ieee80211_agg_splice_finish(sta->sdata, tid);
+
+ kfree_rcu(tid_tx, rcu_head);
+}
+
+int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
+ enum ieee80211_agg_stop_reason reason)
+{
+ struct ieee80211_local *local = sta->local;
+ struct tid_ampdu_tx *tid_tx;
+ enum ieee80211_ampdu_mlme_action action;
+ int ret;
+
+ lockdep_assert_held(&sta->ampdu_mlme.mtx);
+
+ switch (reason) {
+ case AGG_STOP_DECLINED:
+ case AGG_STOP_LOCAL_REQUEST:
+ case AGG_STOP_PEER_REQUEST:
+ action = IEEE80211_AMPDU_TX_STOP_CONT;
+ break;
+ case AGG_STOP_DESTROY_STA:
+ action = IEEE80211_AMPDU_TX_STOP_FLUSH;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+
+ spin_lock_bh(&sta->lock);
+
+ tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
+ if (!tid_tx) {
+ spin_unlock_bh(&sta->lock);
+ return -ENOENT;
+ }
+
+ /*
+ * if we're already stopping ignore any new requests to stop
+ * unless we're destroying it in which case notify the driver
+ */
+ if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
+ spin_unlock_bh(&sta->lock);
+ if (reason != AGG_STOP_DESTROY_STA)
+ return -EALREADY;
+ ret = drv_ampdu_action(local, sta->sdata,
+ IEEE80211_AMPDU_TX_STOP_FLUSH_CONT,
+ &sta->sta, tid, NULL, 0);
+ WARN_ON_ONCE(ret);
+ return 0;
+ }
+
+ if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
+ /* not even started yet! */
+ ieee80211_assign_tid_tx(sta, tid, NULL);
+ spin_unlock_bh(&sta->lock);
+ kfree_rcu(tid_tx, rcu_head);
+ return 0;
+ }
+
+ set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
+
+ spin_unlock_bh(&sta->lock);
+
+ ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n",
+ sta->sta.addr, tid);
+
+ del_timer_sync(&tid_tx->addba_resp_timer);
+ del_timer_sync(&tid_tx->session_timer);
+
+ /*
+ * 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);
+
+ /*
+ * There might be a few packets being processed right now (on
+ * another CPU) that have already gotten past the aggregation
+ * check when it was still OPERATIONAL and consequently have
+ * IEEE80211_TX_CTL_AMPDU set. In that case, this code might
+ * call into the driver at the same time or even before the
+ * TX paths calls into it, which could confuse the driver.
+ *
+ * Wait for all currently running TX paths to finish before
+ * telling the driver. New packets will not go through since
+ * the aggregation session is no longer OPERATIONAL.
+ */
+ synchronize_net();
+
+ tid_tx->stop_initiator = reason == AGG_STOP_PEER_REQUEST ?
+ WLAN_BACK_RECIPIENT :
+ WLAN_BACK_INITIATOR;
+ tid_tx->tx_stop = reason == AGG_STOP_LOCAL_REQUEST;
+
+ ret = drv_ampdu_action(local, sta->sdata, action,
+ &sta->sta, tid, NULL, 0);
+
+ /* HW shall not deny going back to legacy */
+ if (WARN_ON(ret)) {
+ /*
+ * We may have pending packets get stuck in this case...
+ * Not bothering with a workaround for now.
+ */
+ }
+
+ /*
+ * In the case of AGG_STOP_DESTROY_STA, the driver won't
+ * necessarily call ieee80211_stop_tx_ba_cb(), so this may
+ * seem like we can leave the tid_tx data pending forever.
+ * This is true, in a way, but "forever" is only until the
+ * station struct is actually destroyed. In the meantime,
+ * leaving it around ensures that we don't transmit packets
+ * to the driver on this TID which might confuse it.
+ */
+
+ return 0;
+}
+
+/*
+ * After sending add Block Ack request we activated a timer until
+ * add Block Ack response will arrive from the recipient.
+ * If this timer expires sta_addba_resp_timer_expired will be executed.
+ */
+static void sta_addba_resp_timer_expired(unsigned long data)
+{
+ /* not an elegant detour, but there is no choice as the timer passes
+ * only one argument, and both sta_info and TID are needed, so init
+ * flow in sta_info_create gives the TID as data, while the timer_to_id
+ * array gives the sta through container_of */
+ u16 tid = *(u8 *)data;
+ struct sta_info *sta = container_of((void *)data,
+ struct sta_info, timer_to_tid[tid]);
+ struct tid_ampdu_tx *tid_tx;
+
+ /* check if the TID waits for addBA response */
+ rcu_read_lock();
+ tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
+ if (!tid_tx ||
+ test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
+ rcu_read_unlock();
+ ht_dbg(sta->sdata,
+ "timer expired on %pM tid %d but we are not (or no longer) expecting addBA response there\n",
+ sta->sta.addr, tid);
+ return;
+ }
+
+ ht_dbg(sta->sdata, "addBA response timer expired on %pM tid %d\n",
+ sta->sta.addr, tid);
+
+ ieee80211_stop_tx_ba_session(&sta->sta, tid);
+ rcu_read_unlock();
+}
+
+void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
+{
+ struct tid_ampdu_tx *tid_tx;
+ struct ieee80211_local *local = sta->local;
+ struct ieee80211_sub_if_data *sdata = sta->sdata;
+ u16 start_seq_num;
+ int ret;
+
+ tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
+
+ /*
+ * Start queuing up packets for this aggregation session.
+ * We're going to release them once the driver is OK with
+ * that.
+ */
+ clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
+
+ /*
+ * Make sure no packets are being processed. This ensures that
+ * we have a valid starting sequence number and that in-flight
+ * packets have been flushed out and no packets for this TID
+ * will go into the driver during the ampdu_action call.
+ */
+ synchronize_net();
+
+ start_seq_num = sta->tid_seq[tid] >> 4;
+
+ ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
+ &sta->sta, tid, &start_seq_num, 0);
+ if (ret) {
+ ht_dbg(sdata,
+ "BA request denied - HW unavailable for %pM tid %d\n",
+ sta->sta.addr, tid);
+ spin_lock_bh(&sta->lock);
+ ieee80211_agg_splice_packets(sdata, tid_tx, tid);
+ ieee80211_assign_tid_tx(sta, tid, NULL);
+ ieee80211_agg_splice_finish(sdata, tid);
+ spin_unlock_bh(&sta->lock);
+
+ kfree_rcu(tid_tx, rcu_head);
+ return;
+ }
+
+ /* activate the timer for the recipient's addBA response */
+ mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
+ ht_dbg(sdata, "activated addBA response timer on %pM tid %d\n",
+ sta->sta.addr, tid);
+
+ spin_lock_bh(&sta->lock);
+ sta->ampdu_mlme.last_addba_req_time[tid] = jiffies;
+ sta->ampdu_mlme.addba_req_num[tid]++;
+ spin_unlock_bh(&sta->lock);
+
+ /* send AddBA request */
+ ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
+ tid_tx->dialog_token, start_seq_num,
+ local->hw.max_tx_aggregation_subframes,
+ tid_tx->timeout);
+}
+
+/*
+ * After accepting the AddBA Response we activated a timer,
+ * resetting it after each frame that we send.
+ */
+static void sta_tx_agg_session_timer_expired(unsigned long data)
+{
+ /* not an elegant detour, but there is no choice as the timer passes
+ * only one argument, and various sta_info are needed here, so init
+ * flow in sta_info_create gives the TID as data, while the timer_to_id
+ * array gives the sta through container_of */
+ u8 *ptid = (u8 *)data;
+ u8 *timer_to_id = ptid - *ptid;
+ struct sta_info *sta = container_of(timer_to_id, struct sta_info,
+ timer_to_tid[0]);
+ struct tid_ampdu_tx *tid_tx;
+ unsigned long timeout;
+
+ rcu_read_lock();
+ tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[*ptid]);
+ if (!tid_tx || test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
+ rcu_read_unlock();
+ return;
+ }
+
+ timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout);
+ if (time_is_after_jiffies(timeout)) {
+ mod_timer(&tid_tx->session_timer, timeout);
+ rcu_read_unlock();
+ return;
+ }
+
+ rcu_read_unlock();
+
+ ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n",
+ sta->sta.addr, (u16)*ptid);
+
+ ieee80211_stop_tx_ba_session(&sta->sta, *ptid);
+}
+
+int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
+ u16 timeout)
+{
+ 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_start_tx_ba_session(pubsta, tid);
+
+ if (WARN_ON_ONCE(!local->ops->ampdu_action))
+ return -EINVAL;
+
+ if ((tid >= IEEE80211_NUM_TIDS) ||
+ !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) ||
+ (local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW))
+ return -EINVAL;
+
+ ht_dbg(sdata, "Open BA session requested for %pM tid %u\n",
+ pubsta->addr, tid);
+
+ if (sdata->vif.type != NL80211_IFTYPE_STATION &&
+ sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
+ sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
+ sdata->vif.type != NL80211_IFTYPE_AP &&
+ sdata->vif.type != NL80211_IFTYPE_ADHOC)
+ return -EINVAL;
+
+ if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
+ ht_dbg(sdata,
+ "BA sessions blocked - Denying BA session request %pM tid %d\n",
+ sta->sta.addr, tid);
+ return -EINVAL;
+ }
+
+ /*
+ * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a
+ * member of an IBSS, and has no other existing Block Ack agreement
+ * with the recipient STA, then the initiating STA shall transmit a
+ * Probe Request frame to the recipient STA and shall not transmit an
+ * ADDBA Request frame unless it receives a Probe Response frame
+ * from the recipient within dot11ADDBAFailureTimeout.
+ *
+ * The probe request mechanism for ADDBA is currently not implemented,
+ * but we only build up Block Ack session with HT STAs. This information
+ * is set when we receive a bss info from a probe response or a beacon.
+ */
+ if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC &&
+ !sta->sta.ht_cap.ht_supported) {
+ ht_dbg(sdata,
+ "BA request denied - IBSS STA %pM does not advertise HT support\n",
+ pubsta->addr);
+ return -EINVAL;
+ }
+
+ 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) {
+ ret = -EBUSY;
+ goto err_unlock_sta;
+ }
+
+ /*
+ * if we have tried more than HT_AGG_BURST_RETRIES times we
+ * will spread our requests in time to avoid stalling connection
+ * for too long
+ */
+ if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES &&
+ time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] +
+ HT_AGG_RETRIES_PERIOD)) {
+ ht_dbg(sdata,
+ "BA request denied - waiting a grace period after %d failed requests on %pM tid %u\n",
+ sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, tid);
+ ret = -EBUSY;
+ goto err_unlock_sta;
+ }
+
+ tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
+ /* check if the TID is not in aggregation flow already */
+ if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
+ ht_dbg(sdata,
+ "BA request denied - session is not idle on %pM tid %u\n",
+ sta->sta.addr, tid);
+ ret = -EAGAIN;
+ goto err_unlock_sta;
+ }
+
+ /* prepare A-MPDU MLME for Tx aggregation */
+ tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
+ if (!tid_tx) {
+ ret = -ENOMEM;
+ goto err_unlock_sta;
+ }
+
+ skb_queue_head_init(&tid_tx->pending);
+ __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
+
+ tid_tx->timeout = timeout;
+
+ /* response 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);
+
+ /* tx timer */
+ tid_tx->session_timer.function = sta_tx_agg_session_timer_expired;
+ tid_tx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
+ init_timer_deferrable(&tid_tx->session_timer);
+
+ /* assign a dialog token */
+ sta->ampdu_mlme.dialog_token_allocator++;
+ tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
+
+ /*
+ * Finally, assign it to the start array; the work item will
+ * collect it and move it to the normal array.
+ */
+ sta->ampdu_mlme.tid_start_tx[tid] = tid_tx;
+
+ ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
+
+ /* this flow continues off the work */
+ err_unlock_sta:
+ spin_unlock_bh(&sta->lock);
+ return ret;
+}
+EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
+
+static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
+ struct sta_info *sta, u16 tid)
+{
+ struct tid_ampdu_tx *tid_tx;
+
+ lockdep_assert_held(&sta->ampdu_mlme.mtx);
+
+ tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
+
+ ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n",
+ sta->sta.addr, tid);
+
+ drv_ampdu_action(local, sta->sdata,
+ IEEE80211_AMPDU_TX_OPERATIONAL,
+ &sta->sta, tid, NULL, tid_tx->buf_size);
+
+ /*
+ * synchronize with TX path, while splicing the TX path
+ * should block so it won't put more packets onto pending.
+ */
+ spin_lock_bh(&sta->lock);
+
+ ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
+ /*
+ * Now mark as operational. This will be visible
+ * in the TX path, and lets it go lock-free in
+ * the common case.
+ */
+ set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
+ ieee80211_agg_splice_finish(sta->sdata, tid);
+
+ spin_unlock_bh(&sta->lock);
+}
+
+void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
+{
+ struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+ struct ieee80211_local *local = sdata->local;
+ struct sta_info *sta;
+ struct tid_ampdu_tx *tid_tx;
+
+ trace_api_start_tx_ba_cb(sdata, ra, tid);
+
+ if (tid >= IEEE80211_NUM_TIDS) {
+ ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
+ tid, IEEE80211_NUM_TIDS);
+ return;
+ }
+
+ mutex_lock(&local->sta_mtx);
+ sta = sta_info_get_bss(sdata, ra);
+ if (!sta) {
+ mutex_unlock(&local->sta_mtx);
+ ht_dbg(sdata, "Could not find station: %pM\n", ra);
+ return;
+ }
+
+ mutex_lock(&sta->ampdu_mlme.mtx);
+ tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
+
+ if (WARN_ON(!tid_tx)) {
+ ht_dbg(sdata, "addBA was not requested!\n");
+ goto unlock;
+ }
+
+ if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
+ goto unlock;
+
+ if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
+ ieee80211_agg_tx_operational(local, sta, tid);
+
+ unlock:
+ mutex_unlock(&sta->ampdu_mlme.mtx);
+ mutex_unlock(&local->sta_mtx);
+}
+
+void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
+ const u8 *ra, u16 tid)
+{
+ struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+ struct ieee80211_local *local = sdata->local;
+ struct ieee80211_ra_tid *ra_tid;
+ struct sk_buff *skb = dev_alloc_skb(0);
+
+ if (unlikely(!skb))
+ return;
+
+ ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
+ memcpy(&ra_tid->ra, ra, ETH_ALEN);
+ ra_tid->tid = tid;
+
+ skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START;
+ skb_queue_tail(&sdata->skb_queue, skb);
+ ieee80211_queue_work(&local->hw, &sdata->work);
+}
+EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
+
+int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
+ enum ieee80211_agg_stop_reason reason)
+{
+ int ret;
+
+ mutex_lock(&sta->ampdu_mlme.mtx);
+
+ ret = ___ieee80211_stop_tx_ba_session(sta, tid, reason);
+
+ mutex_unlock(&sta->ampdu_mlme.mtx);
+
+ return ret;
+}
+
+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);
+
+ if (!local->ops->ampdu_action)
+ return -EINVAL;
+
+ if (tid >= IEEE80211_NUM_TIDS)
+ return -EINVAL;
+
+ spin_lock_bh(&sta->lock);
+ tid_tx = rcu_dereference_protected_tid_tx(sta, 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);
+
+void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
+{
+ struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+ struct ieee80211_local *local = sdata->local;
+ struct sta_info *sta;
+ struct tid_ampdu_tx *tid_tx;
+
+ trace_api_stop_tx_ba_cb(sdata, ra, tid);
+
+ if (tid >= IEEE80211_NUM_TIDS) {
+ ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
+ tid, IEEE80211_NUM_TIDS);
+ return;
+ }
+
+ ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", ra, tid);
+
+ mutex_lock(&local->sta_mtx);
+
+ sta = sta_info_get_bss(sdata, ra);
+ if (!sta) {
+ ht_dbg(sdata, "Could not find station: %pM\n", ra);
+ goto unlock;
+ }
+
+ mutex_lock(&sta->ampdu_mlme.mtx);
+ spin_lock_bh(&sta->lock);
+ tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
+
+ if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
+ ht_dbg(sdata,
+ "unexpected callback to A-MPDU stop for %pM tid %d\n",
+ sta->sta.addr, tid);
+ goto unlock_sta;
+ }
+
+ if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop)
+ ieee80211_send_delba(sta->sdata, ra, tid,
+ WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
+
+ ieee80211_remove_tid_tx(sta, tid);
+
+ unlock_sta:
+ spin_unlock_bh(&sta->lock);
+ mutex_unlock(&sta->ampdu_mlme.mtx);
+ unlock:
+ mutex_unlock(&local->sta_mtx);
+}
+
+void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
+ const u8 *ra, u16 tid)
+{
+ struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+ struct ieee80211_local *local = sdata->local;
+ struct ieee80211_ra_tid *ra_tid;
+ struct sk_buff *skb = dev_alloc_skb(0);
+
+ if (unlikely(!skb))
+ return;
+
+ ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
+ memcpy(&ra_tid->ra, ra, ETH_ALEN);
+ ra_tid->tid = tid;
+
+ skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP;
+ skb_queue_tail(&sdata->skb_queue, skb);
+ ieee80211_queue_work(&local->hw, &sdata->work);
+}
+EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
+
+
+void ieee80211_process_addba_resp(struct ieee80211_local *local,
+ struct sta_info *sta,
+ struct ieee80211_mgmt *mgmt,
+ size_t len)
+{
+ struct tid_ampdu_tx *tid_tx;
+ u16 capab, tid;
+ u8 buf_size;
+
+ capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
+ tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
+ buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
+
+ mutex_lock(&sta->ampdu_mlme.mtx);
+
+ tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
+ if (!tid_tx)
+ goto out;
+
+ if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
+ ht_dbg(sta->sdata, "wrong addBA response token, %pM tid %d\n",
+ sta->sta.addr, tid);
+ goto out;
+ }
+
+ del_timer_sync(&tid_tx->addba_resp_timer);
+
+ ht_dbg(sta->sdata, "switched off addBA timer for %pM tid %d\n",
+ sta->sta.addr, tid);
+
+ /*
+ * addba_resp_timer may have fired before we got here, and
+ * caused WANT_STOP to be set. If the stop then was already
+ * processed further, STOPPING might be set.
+ */
+ if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) ||
+ test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
+ ht_dbg(sta->sdata,
+ "got addBA resp for %pM tid %d but we already gave up\n",
+ sta->sta.addr, tid);
+ goto out;
+ }
+
+ /*
+ * IEEE 802.11-2007 7.3.1.14:
+ * In an ADDBA Response frame, when the Status Code field
+ * is set to 0, the Buffer Size subfield is set to a value
+ * of at least 1.
+ */
+ if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
+ == WLAN_STATUS_SUCCESS && buf_size) {
+ if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
+ &tid_tx->state)) {
+ /* ignore duplicate response */
+ goto out;
+ }
+
+ tid_tx->buf_size = buf_size;
+
+ 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;
+
+ if (tid_tx->timeout) {
+ mod_timer(&tid_tx->session_timer,
+ TU_TO_EXP_TIME(tid_tx->timeout));
+ tid_tx->last_tx = jiffies;
+ }
+
+ } else {
+ ___ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_DECLINED);
+ }
+
+ out:
+ mutex_unlock(&sta->ampdu_mlme.mtx);
+}