[deliverable/linux.git] / net / mac80211 / agg-tx.c

/*
 * 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 2007-2009, 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 <net/mac80211.h>
#include "ieee80211_i.h"
#include "wme.h"

/**
 * DOC: TX aggregation
 *
 * Aggregation on the TX side requires setting the hardware flag
 * %IEEE80211_HW_AMPDU_AGGREGATION as well as, if present, the @ampdu_queues
 * hardware parameter to the number of hardware AMPDU queues. If there are no
 * hardware queues then the driver will (currently) have to do all frame
 * buffering.
 *
 * 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() (or ieee80211_start_tx_ba_cb_irqsafe())
 * function, which will start the aggregation session.
 *
 * Similarly, when the aggregation session is stopped by
 * 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()
 * (or ieee80211_stop_tx_ba_cb_irqsafe()).
 */

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 ieee80211_if_sta *ifsta = &sdata->u.sta;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u16 capab;

	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);

	if (!skb) {
		printk(KERN_ERR "%s: failed to allocate buffer "
				"for addba request frame\n", sdata->dev->name);
		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->dev->dev_addr, ETH_ALEN);
	if (sdata->vif.type == NL80211_IFTYPE_AP ||
	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
		memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
	else
		memcpy(mgmt->bssid, ifsta->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(sdata, skb, 1);
}

void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
{
	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) {
		printk(KERN_ERR "%s: failed to allocate buffer for "
			"bar frame\n", sdata->dev->name);
		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->dev->dev_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 << 12);
	bar->control = cpu_to_le16(bar_control);
	bar->start_seq_num = cpu_to_le16(ssn);

	ieee80211_tx_skb(sdata, skb, 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 *temp_sta = container_of((void *)data,
		struct sta_info, timer_to_tid[tid]);

	struct ieee80211_local *local = temp_sta->local;
	struct ieee80211_hw *hw = &local->hw;
	struct sta_info *sta;
	u8 *state;

	rcu_read_lock();

	sta = sta_info_get(local, temp_sta->sta.addr);
	if (!sta) {
		rcu_read_unlock();
		return;
	}

	state = &sta->ampdu_mlme.tid_state_tx[tid];
	/* check if the TID waits for addBA response */
	spin_lock_bh(&sta->lock);
	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
		spin_unlock_bh(&sta->lock);
		*state = HT_AGG_STATE_IDLE;
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "timer expired on tid %d but we are not "
				"expecting addBA response there", tid);
#endif
		goto timer_expired_exit;
	}

#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
#endif

	/* go through the state check in stop_BA_session */
	*state = HT_AGG_STATE_OPERATIONAL;
	spin_unlock_bh(&sta->lock);
	ieee80211_stop_tx_ba_session(hw, temp_sta->sta.addr, tid,
				     WLAN_BACK_INITIATOR);

timer_expired_exit:
	rcu_read_unlock();
}

int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct sta_info *sta;
	struct ieee80211_sub_if_data *sdata;
	u16 start_seq_num;
	u8 *state;
	int ret = 0;

	if ((tid >= STA_TID_NUM) || !(hw->flags & IEEE80211_HW_AMPDU_AGGREGATION))
		return -EINVAL;

#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
	       ra, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

	rcu_read_lock();

	sta = sta_info_get(local, ra);
	if (!sta) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Could not find the station\n");
#endif
		ret = -ENOENT;
		goto exit;
	}

	/*
	 * The aggregation code is not prepared to handle
	 * anything but STA/AP due to the BSSID handling.
	 * IBSS could work in the code but isn't supported
	 * by drivers or the standard.
	 */
	if (sta->sdata->vif.type != NL80211_IFTYPE_STATION &&
	    sta->sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
	    sta->sdata->vif.type != NL80211_IFTYPE_AP) {
		ret = -EINVAL;
		goto exit;
	}

	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;
	}

	state = &sta->ampdu_mlme.tid_state_tx[tid];
	/* check if the TID is not in aggregation flow already */
	if (*state != HT_AGG_STATE_IDLE) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "BA request denied - session is not "
				 "idle on tid %u\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
		ret = -EAGAIN;
		goto err_unlock_sta;
	}

	/* 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]) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
					tid);
#endif
		ret = -ENOMEM;
		goto err_unlock_sta;
	}
	/* 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);

	if (hw->ampdu_queues) {
		/* create a new queue for this aggregation */
		ret = ieee80211_ht_agg_queue_add(local, sta, tid);

		/* case no queue is available to aggregation
		 * don't switch to aggregation */
		if (ret) {
#ifdef CONFIG_MAC80211_HT_DEBUG
			printk(KERN_DEBUG "BA request denied - "
			       "queue unavailable for tid %d\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
			goto err_unlock_queue;
		}
	}
	sdata = sta->sdata;

	/* 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;

	/* This is slightly racy because the queue isn't stopped */
	start_seq_num = sta->tid_seq[tid];

	if (local->ops->ampdu_action)
		ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_START,
					       &sta->sta, tid, &start_seq_num);

	if (ret) {
		/* No need to requeue the packets in the agg queue, since we
		 * held the tx lock: no packet could be enqueued to the newly
		 * allocated queue */
		if (hw->ampdu_queues)
			ieee80211_ht_agg_queue_remove(local, sta, tid, 0);
#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_unlock_queue;
	}

	/* Will put all the packets in the new SW queue */
	if (hw->ampdu_queues)
		ieee80211_requeue(local, ieee802_1d_to_ac[tid]);
	spin_unlock_bh(&sta->lock);

	/* send an addBA request */
	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;


	ieee80211_send_addba_request(sta->sdata, ra, tid,
			 sta->ampdu_mlme.tid_tx[tid]->dialog_token,
			 sta->ampdu_mlme.tid_tx[tid]->ssn,
			 0x40, 5000);
	/* 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
	goto exit;

err_unlock_queue:
	kfree(sta->ampdu_mlme.tid_tx[tid]);
	sta->ampdu_mlme.tid_tx[tid] = NULL;
	ret = -EBUSY;
err_unlock_sta:
	spin_unlock_bh(&sta->lock);
exit:
	rcu_read_unlock();
	return ret;
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_session);

void ieee80211_start_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u16 tid)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct sta_info *sta;
	u8 *state;

	if (tid >= STA_TID_NUM) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
				tid, STA_TID_NUM);
#endif
		return;
	}

	rcu_read_lock();
	sta = sta_info_get(local, ra);
	if (!sta) {
		rcu_read_unlock();
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Could not find station: %pM\n", ra);
#endif
		return;
	}

	state = &sta->ampdu_mlme.tid_state_tx[tid];
	spin_lock_bh(&sta->lock);

	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
				*state);
#endif
		spin_unlock_bh(&sta->lock);
		rcu_read_unlock();
		return;
	}

	WARN_ON_ONCE(*state & HT_ADDBA_DRV_READY_MSK);

	*state |= HT_ADDBA_DRV_READY_MSK;

	if (*state == HT_AGG_STATE_OPERATIONAL) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
#endif
		if (hw->ampdu_queues)
			ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
	}
	spin_unlock_bh(&sta->lock);
	rcu_read_unlock();
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);

void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
				      const u8 *ra, u16 tid)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_ra_tid *ra_tid;
	struct sk_buff *skb = dev_alloc_skb(0);

	if (unlikely(!skb)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_WARNING "%s: Not enough memory, "
			       "dropping start BA session", skb->dev->name);
#endif
		return;
	}
	ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
	memcpy(&ra_tid->ra, ra, ETH_ALEN);
	ra_tid->tid = tid;

	skb->pkt_type = IEEE80211_ADDBA_MSG;
	skb_queue_tail(&local->skb_queue, skb);
	tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);


int ieee80211_stop_tx_ba_session(struct ieee80211_hw *hw,
				 u8 *ra, u16 tid,
				 enum ieee80211_back_parties initiator)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct sta_info *sta;
	u8 *state;
	int ret = 0;

	if (tid >= STA_TID_NUM)
		return -EINVAL;

	rcu_read_lock();
	sta = sta_info_get(local, ra);
	if (!sta) {
		rcu_read_unlock();
		return -ENOENT;
	}

	/* check if the TID is in aggregation */
	state = &sta->ampdu_mlme.tid_state_tx[tid];
	spin_lock_bh(&sta->lock);

	if (*state != HT_AGG_STATE_OPERATIONAL) {
		ret = -ENOENT;
		goto stop_BA_exit;
	}

#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
	       ra, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

	if (hw->ampdu_queues)
		ieee80211_stop_queue(hw, sta->tid_to_tx_q[tid]);

	*state = HT_AGG_STATE_REQ_STOP_BA_MSK |
		(initiator << HT_AGG_STATE_INITIATOR_SHIFT);

	if (local->ops->ampdu_action)
		ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_STOP,
					       &sta->sta, tid, NULL);

	/* HW shall not deny going back to legacy */
	if (WARN_ON(ret)) {
		*state = HT_AGG_STATE_OPERATIONAL;
		if (hw->ampdu_queues)
			ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
		goto stop_BA_exit;
	}

stop_BA_exit:
	spin_unlock_bh(&sta->lock);
	rcu_read_unlock();
	return ret;
}
EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);

void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct sta_info *sta;
	u8 *state;
	int agg_queue;

	if (tid >= STA_TID_NUM) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
				tid, STA_TID_NUM);
#endif
		return;
	}

#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
	       ra, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

	rcu_read_lock();
	sta = sta_info_get(local, ra);
	if (!sta) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Could not find station: %pM\n", ra);
#endif
		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) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
#endif
		rcu_read_unlock();
		return;
	}

	if (*state & HT_AGG_STATE_INITIATOR_MSK)
		ieee80211_send_delba(sta->sdata, ra, tid,
			WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);

	if (hw->ampdu_queues) {
		agg_queue = sta->tid_to_tx_q[tid];
		ieee80211_ht_agg_queue_remove(local, sta, tid, 1);

		/* We just requeued the all the frames that were in the
		 * removed queue, and since we might miss a softirq we do
		 * netif_schedule_queue.  ieee80211_wake_queue is not used
		 * here as this queue is not necessarily stopped
		 */
		netif_schedule_queue(netdev_get_tx_queue(local->mdev,
							 agg_queue));
	}
	spin_lock_bh(&sta->lock);
	*state = HT_AGG_STATE_IDLE;
	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->lock);

	rcu_read_unlock();
}
EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);

void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
				     const u8 *ra, u16 tid)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_ra_tid *ra_tid;
	struct sk_buff *skb = dev_alloc_skb(0);

	if (unlikely(!skb)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_WARNING "%s: Not enough memory, "
			       "dropping stop BA session", skb->dev->name);
#endif
		return;
	}
	ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
	memcpy(&ra_tid->ra, ra, ETH_ALEN);
	ra_tid->tid = tid;

	skb->pkt_type = IEEE80211_DELBA_MSG;
	skb_queue_tail(&local->skb_queue, skb);
	tasklet_schedule(&local->tasklet);
}
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 ieee80211_hw *hw = &local->hw;
	u16 capab;
	u16 tid, start_seq_num;
	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)) {
		spin_unlock_bh(&sta->lock);
		return;
	}

	if (mgmt->u.action.u.addba_resp.dialog_token !=
		sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
		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 */
		return;
	}

	del_timer_sync(&sta->ampdu_mlme.tid_tx[tid]->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 */
	if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
			== WLAN_STATUS_SUCCESS) {
		*state |= HT_ADDBA_RECEIVED_MSK;
		sta->ampdu_mlme.addba_req_num[tid] = 0;

		if (*state == HT_AGG_STATE_OPERATIONAL &&
		    local->hw.ampdu_queues)
			ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);

		if (local->ops->ampdu_action) {
			(void)local->ops->ampdu_action(hw,
					       IEEE80211_AMPDU_TX_RESUME,
					       &sta->sta, tid, &start_seq_num);
		}
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Resuming TX aggregation for tid %d\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
		spin_unlock_bh(&sta->lock);
	} else {
		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->lock);
		ieee80211_stop_tx_ba_session(hw, sta->sta.addr, tid,
					     WLAN_BACK_INITIATOR);
	}
}
Commit	Line	Data
b8695a8f JB	1	/*
	2	* HT handling
	3	*
	4	* Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
	5	* Copyright 2002-2005, Instant802 Networks, Inc.
	6	* Copyright 2005-2006, Devicescape Software, Inc.
	7	* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
	8	* Copyright 2007, Michael Wu <flamingice@sourmilk.net>
	9	* Copyright 2007-2009, Intel Corporation
	10	*
	11	* This program is free software; you can redistribute it and/or modify
	12	* it under the terms of the GNU General Public License version 2 as
	13	* published by the Free Software Foundation.
	14	*/
	15
	16	#include <linux/ieee80211.h>
	17	#include <net/mac80211.h>
	18	#include "ieee80211_i.h"
	19	#include "wme.h"
	20
86ab6c5a JB	21	/**
	22	* DOC: TX aggregation
	23	*
	24	* Aggregation on the TX side requires setting the hardware flag
	25	* %IEEE80211_HW_AMPDU_AGGREGATION as well as, if present, the @ampdu_queues
	26	* hardware parameter to the number of hardware AMPDU queues. If there are no
	27	* hardware queues then the driver will (currently) have to do all frame
	28	* buffering.
	29	*
	30	* When TX aggregation is started by some subsystem (usually the rate control
	31	* algorithm would be appropriate) by calling the
	32	* ieee80211_start_tx_ba_session() function, the driver will be notified via
	33	* its @ampdu_action function, with the %IEEE80211_AMPDU_TX_START action.
	34	*
	35	* In response to that, the driver is later required to call the
	36	* ieee80211_start_tx_ba_cb() (or ieee80211_start_tx_ba_cb_irqsafe())
	37	* function, which will start the aggregation session.
	38	*
	39	* Similarly, when the aggregation session is stopped by
	40	* ieee80211_stop_tx_ba_session(), the driver's @ampdu_action function will
	41	* be called with the action %IEEE80211_AMPDU_TX_STOP. In this case, the
	42	* call must not fail, and the driver must later call ieee80211_stop_tx_ba_cb()
	43	* (or ieee80211_stop_tx_ba_cb_irqsafe()).
	44	*/
	45
b8695a8f JB	46	static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
	47	const u8 *da, u16 tid,
	48	u8 dialog_token, u16 start_seq_num,
	49	u16 agg_size, u16 timeout)
	50	{
	51	struct ieee80211_local *local = sdata->local;
	52	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
	53	struct sk_buff *skb;
	54	struct ieee80211_mgmt *mgmt;
	55	u16 capab;
	56
	57	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
	58
	59	if (!skb) {
	60	printk(KERN_ERR "%s: failed to allocate buffer "
	61	"for addba request frame\n", sdata->dev->name);
	62	return;
	63	}
	64	skb_reserve(skb, local->hw.extra_tx_headroom);
	65	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
	66	memset(mgmt, 0, 24);
	67	memcpy(mgmt->da, da, ETH_ALEN);
	68	memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
8abd3f9b JB	69	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
8abd3f9b JB	70	sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
b8695a8f JB	71	memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
	72	else
	73	memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
	74
	75	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT \|
	76	IEEE80211_STYPE_ACTION);
	77
	78	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
	79
	80	mgmt->u.action.category = WLAN_CATEGORY_BACK;
	81	mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
	82
	83	mgmt->u.action.u.addba_req.dialog_token = dialog_token;
	84	capab = (u16)(1 << 1); /* bit 1 aggregation policy */
	85	capab \|= (u16)(tid << 2); /* bit 5:2 TID number */
	86	capab \|= (u16)(agg_size << 6); /* bit 15:6 max size of aggergation */
	87
	88	mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
	89
	90	mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
	91	mgmt->u.action.u.addba_req.start_seq_num =
	92	cpu_to_le16(start_seq_num << 4);
	93
	94	ieee80211_tx_skb(sdata, skb, 1);
	95	}
	96
	97	void ieee80211_send_bar(struct ieee80211_sub_if_data sdata, u8 ra, u16 tid, u16 ssn)
	98	{
	99	struct ieee80211_local *local = sdata->local;
	100	struct sk_buff *skb;
	101	struct ieee80211_bar *bar;
	102	u16 bar_control = 0;
	103
	104	skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
	105	if (!skb) {
	106	printk(KERN_ERR "%s: failed to allocate buffer for "
	107	"bar frame\n", sdata->dev->name);
	108	return;
	109	}
	110	skb_reserve(skb, local->hw.extra_tx_headroom);
	111	bar = (struct ieee80211_bar )skb_put(skb, sizeof(bar));
	112	memset(bar, 0, sizeof(*bar));
	113	bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL \|
	114	IEEE80211_STYPE_BACK_REQ);
	115	memcpy(bar->ra, ra, ETH_ALEN);
	116	memcpy(bar->ta, sdata->dev->dev_addr, ETH_ALEN);
	117	bar_control \|= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
	118	bar_control \|= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
	119	bar_control \|= (u16)(tid << 12);
	120	bar->control = cpu_to_le16(bar_control);
	121	bar->start_seq_num = cpu_to_le16(ssn);
	122
	123	ieee80211_tx_skb(sdata, skb, 0);
	124	}
	125
	126	/*
	127	* After sending add Block Ack request we activated a timer until
	128	* add Block Ack response will arrive from the recipient.
	129	* If this timer expires sta_addba_resp_timer_expired will be executed.
	130	*/
	131	static void sta_addba_resp_timer_expired(unsigned long data)
	132	{
	133	/* not an elegant detour, but there is no choice as the timer passes
	134	* only one argument, and both sta_info and TID are needed, so init
135	* flow in sta_info_create gives the TID as data, while the timer_to_id
136	* array gives the sta through container_of */
137	u16 tid = (u8 )data;
138	struct sta_info temp_sta = container_of((void )data,
139	struct sta_info, timer_to_tid[tid]);
140
141	struct ieee80211_local *local = temp_sta->local;
142	struct ieee80211_hw *hw = &local->hw;
143	struct sta_info *sta;
144	u8 *state;
145
146	rcu_read_lock();
147
148	sta = sta_info_get(local, temp_sta->sta.addr);
149	if (!sta) {
150	rcu_read_unlock();
151	return;
152	}
153
154	state = &sta->ampdu_mlme.tid_state_tx[tid];
155	/* check if the TID waits for addBA response */
156	spin_lock_bh(&sta->lock);
157	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
158	spin_unlock_bh(&sta->lock);
159	*state = HT_AGG_STATE_IDLE;
160	#ifdef CONFIG_MAC80211_HT_DEBUG
161	printk(KERN_DEBUG "timer expired on tid %d but we are not "
162	"expecting addBA response there", tid);
163	#endif
164	goto timer_expired_exit;
165	}
166
167	#ifdef CONFIG_MAC80211_HT_DEBUG
168	printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
169	#endif
170
171	/* go through the state check in stop_BA_session */
172	*state = HT_AGG_STATE_OPERATIONAL;
173	spin_unlock_bh(&sta->lock);
174	ieee80211_stop_tx_ba_session(hw, temp_sta->sta.addr, tid,
175	WLAN_BACK_INITIATOR);
176
177	timer_expired_exit:
178	rcu_read_unlock();
179	}
180
181	int ieee80211_start_tx_ba_session(struct ieee80211_hw hw, u8 ra, u16 tid)
182	{
183	struct ieee80211_local *local = hw_to_local(hw);
184	struct sta_info *sta;
185	struct ieee80211_sub_if_data *sdata;
186	u16 start_seq_num;
187	u8 *state;
188	int ret = 0;
189
190	if ((tid >= STA_TID_NUM) \|\| !(hw->flags & IEEE80211_HW_AMPDU_AGGREGATION))
191	return -EINVAL;
192
193	#ifdef CONFIG_MAC80211_HT_DEBUG
194	printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
195	ra, tid);
196	#endif /* CONFIG_MAC80211_HT_DEBUG */
197
198	rcu_read_lock();
199
200	sta = sta_info_get(local, ra);
201	if (!sta) {
202	#ifdef CONFIG_MAC80211_HT_DEBUG
203	printk(KERN_DEBUG "Could not find the station\n");
204	#endif
205	ret = -ENOENT;
206	goto exit;
207	}
208
8abd3f9b JB	209	/*
	210	* The aggregation code is not prepared to handle
	211	* anything but STA/AP due to the BSSID handling.
	212	* IBSS could work in the code but isn't supported
	213	* by drivers or the standard.
	214	*/
	215	if (sta->sdata->vif.type != NL80211_IFTYPE_STATION &&
	216	sta->sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
	217	sta->sdata->vif.type != NL80211_IFTYPE_AP) {
	218	ret = -EINVAL;
	219	goto exit;
	220	}
	221
b8695a8f JB	222	spin_lock_bh(&sta->lock);
	223
	224	/* we have tried too many times, receiver does not want A-MPDU */
	225	if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
	226	ret = -EBUSY;
	227	goto err_unlock_sta;
	228	}
	229
	230	state = &sta->ampdu_mlme.tid_state_tx[tid];
	231	/* check if the TID is not in aggregation flow already */
	232	if (*state != HT_AGG_STATE_IDLE) {
	233	#ifdef CONFIG_MAC80211_HT_DEBUG
	234	printk(KERN_DEBUG "BA request denied - session is not "
	235	"idle on tid %u\n", tid);
	236	#endif /* CONFIG_MAC80211_HT_DEBUG */
	237	ret = -EAGAIN;
	238	goto err_unlock_sta;
	239	}
	240
	241	/* prepare A-MPDU MLME for Tx aggregation */
	242	sta->ampdu_mlme.tid_tx[tid] =
	243	kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
	244	if (!sta->ampdu_mlme.tid_tx[tid]) {
	245	#ifdef CONFIG_MAC80211_HT_DEBUG
	246	if (net_ratelimit())
	247	printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
	248	tid);
	249	#endif
	250	ret = -ENOMEM;
	251	goto err_unlock_sta;
	252	}
	253	/* Tx timer */
	254	sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
	255	sta_addba_resp_timer_expired;
	256	sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
	257	(unsigned long)&sta->timer_to_tid[tid];
	258	init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
	259
	260	if (hw->ampdu_queues) {
	261	/* create a new queue for this aggregation */
	262	ret = ieee80211_ht_agg_queue_add(local, sta, tid);
	263
	264	/* case no queue is available to aggregation
	265	* don't switch to aggregation */
	266	if (ret) {
	267	#ifdef CONFIG_MAC80211_HT_DEBUG
	268	printk(KERN_DEBUG "BA request denied - "
	269	"queue unavailable for tid %d\n", tid);
	270	#endif /* CONFIG_MAC80211_HT_DEBUG */
	271	goto err_unlock_queue;
	272	}
	273	}
	274	sdata = sta->sdata;
	275
	276	/* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
	277	* call back right away, it must see that the flow has begun */
	278	*state \|= HT_ADDBA_REQUESTED_MSK;
	279
	280	/* This is slightly racy because the queue isn't stopped */
	281	start_seq_num = sta->tid_seq[tid];
	282
	283	if (local->ops->ampdu_action)
	284	ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_START,
	285	&sta->sta, tid, &start_seq_num);
286
287	if (ret) {
288	/* No need to requeue the packets in the agg queue, since we
289	* held the tx lock: no packet could be enqueued to the newly
290	* allocated queue */
291	if (hw->ampdu_queues)
292	ieee80211_ht_agg_queue_remove(local, sta, tid, 0);
293	#ifdef CONFIG_MAC80211_HT_DEBUG
294	printk(KERN_DEBUG "BA request denied - HW unavailable for"
295	" tid %d\n", tid);
296	#endif /* CONFIG_MAC80211_HT_DEBUG */
297	*state = HT_AGG_STATE_IDLE;
298	goto err_unlock_queue;
299	}
300
301	/* Will put all the packets in the new SW queue */
302	if (hw->ampdu_queues)
303	ieee80211_requeue(local, ieee802_1d_to_ac[tid]);
304	spin_unlock_bh(&sta->lock);
305
306	/* send an addBA request */
307	sta->ampdu_mlme.dialog_token_allocator++;
308	sta->ampdu_mlme.tid_tx[tid]->dialog_token =
309	sta->ampdu_mlme.dialog_token_allocator;
310	sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
311
312
313	ieee80211_send_addba_request(sta->sdata, ra, tid,
314	sta->ampdu_mlme.tid_tx[tid]->dialog_token,
315	sta->ampdu_mlme.tid_tx[tid]->ssn,
316	0x40, 5000);
317	/* activate the timer for the recipient's addBA response */
318	sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
319	jiffies + ADDBA_RESP_INTERVAL;
320	add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
321	#ifdef CONFIG_MAC80211_HT_DEBUG
322	printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
323	#endif
324	goto exit;
325
326	err_unlock_queue:
327	kfree(sta->ampdu_mlme.tid_tx[tid]);
328	sta->ampdu_mlme.tid_tx[tid] = NULL;
329	ret = -EBUSY;
330	err_unlock_sta:
331	spin_unlock_bh(&sta->lock);
332	exit:
333	rcu_read_unlock();
334	return ret;
335	}
336	EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
337
338	void ieee80211_start_tx_ba_cb(struct ieee80211_hw hw, u8 ra, u16 tid)
339	{
340	struct ieee80211_local *local = hw_to_local(hw);
341	struct sta_info *sta;
342	u8 *state;
343
344	if (tid >= STA_TID_NUM) {
345	#ifdef CONFIG_MAC80211_HT_DEBUG
346	printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
347	tid, STA_TID_NUM);
348	#endif
349	return;
350	}
351
352	rcu_read_lock();
353	sta = sta_info_get(local, ra);
354	if (!sta) {
355	rcu_read_unlock();
356	#ifdef CONFIG_MAC80211_HT_DEBUG
357	printk(KERN_DEBUG "Could not find station: %pM\n", ra);
358	#endif
359	return;
360	}
361
362	state = &sta->ampdu_mlme.tid_state_tx[tid];
363	spin_lock_bh(&sta->lock);
364
365	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
366	#ifdef CONFIG_MAC80211_HT_DEBUG
367	printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
368	*state);
369	#endif
370	spin_unlock_bh(&sta->lock);
371	rcu_read_unlock();
372	return;
373	}
374
375	WARN_ON_ONCE(*state & HT_ADDBA_DRV_READY_MSK);
376
377	*state \|= HT_ADDBA_DRV_READY_MSK;
378
379	if (*state == HT_AGG_STATE_OPERATIONAL) {
380	#ifdef CONFIG_MAC80211_HT_DEBUG
381	printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
382	#endif
383	if (hw->ampdu_queues)
384	ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
385	}
386	spin_unlock_bh(&sta->lock);
387	rcu_read_unlock();
388	}
389	EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
390
86ab6c5a JB	391	void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
	392	const u8 *ra, u16 tid)
	393	{
	394	struct ieee80211_local *local = hw_to_local(hw);
	395	struct ieee80211_ra_tid *ra_tid;
	396	struct sk_buff *skb = dev_alloc_skb(0);
	397
	398	if (unlikely(!skb)) {
	399	#ifdef CONFIG_MAC80211_HT_DEBUG
	400	if (net_ratelimit())
	401	printk(KERN_WARNING "%s: Not enough memory, "
	402	"dropping start BA session", skb->dev->name);
	403	#endif
	404	return;
	405	}
	406	ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
	407	memcpy(&ra_tid->ra, ra, ETH_ALEN);
	408	ra_tid->tid = tid;
	409
	410	skb->pkt_type = IEEE80211_ADDBA_MSG;
	411	skb_queue_tail(&local->skb_queue, skb);
	412	tasklet_schedule(&local->tasklet);
	413	}
	414	EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
	415
b8695a8f JB	416
	417	int ieee80211_stop_tx_ba_session(struct ieee80211_hw *hw,
	418	u8 *ra, u16 tid,
	419	enum ieee80211_back_parties initiator)
	420	{
	421	struct ieee80211_local *local = hw_to_local(hw);
	422	struct sta_info *sta;
	423	u8 *state;
	424	int ret = 0;
	425
	426	if (tid >= STA_TID_NUM)
	427	return -EINVAL;
	428
	429	rcu_read_lock();
	430	sta = sta_info_get(local, ra);
	431	if (!sta) {
	432	rcu_read_unlock();
	433	return -ENOENT;
	434	}
	435
	436	/* check if the TID is in aggregation */
	437	state = &sta->ampdu_mlme.tid_state_tx[tid];
	438	spin_lock_bh(&sta->lock);
	439
	440	if (*state != HT_AGG_STATE_OPERATIONAL) {
	441	ret = -ENOENT;
	442	goto stop_BA_exit;
	443	}
	444
	445	#ifdef CONFIG_MAC80211_HT_DEBUG
	446	printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
	447	ra, tid);
	448	#endif /* CONFIG_MAC80211_HT_DEBUG */
	449
	450	if (hw->ampdu_queues)
	451	ieee80211_stop_queue(hw, sta->tid_to_tx_q[tid]);
	452
	453	*state = HT_AGG_STATE_REQ_STOP_BA_MSK \|
	454	(initiator << HT_AGG_STATE_INITIATOR_SHIFT);
	455
	456	if (local->ops->ampdu_action)
	457	ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_STOP,
	458	&sta->sta, tid, NULL);
	459
955d3fe3 JB	460	/* HW shall not deny going back to legacy */
955d3fe3 JB	461	if (WARN_ON(ret)) {
b8695a8f JB	462	*state = HT_AGG_STATE_OPERATIONAL;
	463	if (hw->ampdu_queues)
	464	ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
	465	goto stop_BA_exit;
	466	}
	467
	468	stop_BA_exit:
	469	spin_unlock_bh(&sta->lock);
	470	rcu_read_unlock();
	471	return ret;
	472	}
	473	EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
	474
	475	void ieee80211_stop_tx_ba_cb(struct ieee80211_hw hw, u8 ra, u8 tid)
	476	{
	477	struct ieee80211_local *local = hw_to_local(hw);
	478	struct sta_info *sta;
	479	u8 *state;
	480	int agg_queue;
	481
	482	if (tid >= STA_TID_NUM) {
	483	#ifdef CONFIG_MAC80211_HT_DEBUG
	484	printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
	485	tid, STA_TID_NUM);
	486	#endif
	487	return;
	488	}
	489
	490	#ifdef CONFIG_MAC80211_HT_DEBUG
	491	printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
	492	ra, tid);
	493	#endif /* CONFIG_MAC80211_HT_DEBUG */
	494
	495	rcu_read_lock();
	496	sta = sta_info_get(local, ra);
	497	if (!sta) {
	498	#ifdef CONFIG_MAC80211_HT_DEBUG
	499	printk(KERN_DEBUG "Could not find station: %pM\n", ra);
	500	#endif
	501	rcu_read_unlock();
	502	return;
	503	}
	504	state = &sta->ampdu_mlme.tid_state_tx[tid];
	505
	506	/* NOTE: no need to use sta->lock in this state check, as
	507	* ieee80211_stop_tx_ba_session will let only one stop call to
	508	* pass through per sta/tid
	509	*/
	510	if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
	511	#ifdef CONFIG_MAC80211_HT_DEBUG
	512	printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
	513	#endif
	514	rcu_read_unlock();
	515	return;
	516	}
	517
	518	if (*state & HT_AGG_STATE_INITIATOR_MSK)
	519	ieee80211_send_delba(sta->sdata, ra, tid,
	520	WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
	521
	522	if (hw->ampdu_queues) {
	523	agg_queue = sta->tid_to_tx_q[tid];
	524	ieee80211_ht_agg_queue_remove(local, sta, tid, 1);
	525
526	/* We just requeued the all the frames that were in the
527	* removed queue, and since we might miss a softirq we do
528	* netif_schedule_queue. ieee80211_wake_queue is not used
529	* here as this queue is not necessarily stopped
530	*/
531	netif_schedule_queue(netdev_get_tx_queue(local->mdev,
532	agg_queue));
533	}
534	spin_lock_bh(&sta->lock);
535	*state = HT_AGG_STATE_IDLE;
536	sta->ampdu_mlme.addba_req_num[tid] = 0;
537	kfree(sta->ampdu_mlme.tid_tx[tid]);
538	sta->ampdu_mlme.tid_tx[tid] = NULL;
539	spin_unlock_bh(&sta->lock);
540
541	rcu_read_unlock();
542	}
543	EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
544
b8695a8f JB	545	void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
	546	const u8 *ra, u16 tid)
	547	{
	548	struct ieee80211_local *local = hw_to_local(hw);
	549	struct ieee80211_ra_tid *ra_tid;
	550	struct sk_buff *skb = dev_alloc_skb(0);
	551
	552	if (unlikely(!skb)) {
	553	#ifdef CONFIG_MAC80211_HT_DEBUG
	554	if (net_ratelimit())
	555	printk(KERN_WARNING "%s: Not enough memory, "
	556	"dropping stop BA session", skb->dev->name);
	557	#endif
	558	return;
	559	}
	560	ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
	561	memcpy(&ra_tid->ra, ra, ETH_ALEN);
	562	ra_tid->tid = tid;
	563
	564	skb->pkt_type = IEEE80211_DELBA_MSG;
	565	skb_queue_tail(&local->skb_queue, skb);
	566	tasklet_schedule(&local->tasklet);
	567	}
	568	EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
	569
86ab6c5a	570
b8695a8f JB	571	void ieee80211_process_addba_resp(struct ieee80211_local *local,
	572	struct sta_info *sta,
	573	struct ieee80211_mgmt *mgmt,
	574	size_t len)
	575	{
	576	struct ieee80211_hw *hw = &local->hw;
	577	u16 capab;
	578	u16 tid, start_seq_num;
	579	u8 *state;
	580
	581	capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
	582	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
	583
	584	state = &sta->ampdu_mlme.tid_state_tx[tid];
	585
	586	spin_lock_bh(&sta->lock);
	587
	588	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
	589	spin_unlock_bh(&sta->lock);
	590	return;
	591	}
	592
	593	if (mgmt->u.action.u.addba_resp.dialog_token !=
	594	sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
	595	spin_unlock_bh(&sta->lock);
	596	#ifdef CONFIG_MAC80211_HT_DEBUG
	597	printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
	598	#endif /* CONFIG_MAC80211_HT_DEBUG */
	599	return;
	600	}
	601
	602	del_timer_sync(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
	603	#ifdef CONFIG_MAC80211_HT_DEBUG
	604	printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
	605	#endif /* CONFIG_MAC80211_HT_DEBUG */
	606	if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
	607	== WLAN_STATUS_SUCCESS) {
	608	*state \|= HT_ADDBA_RECEIVED_MSK;
	609	sta->ampdu_mlme.addba_req_num[tid] = 0;
	610
	611	if (*state == HT_AGG_STATE_OPERATIONAL &&
	612	local->hw.ampdu_queues)
	613	ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
	614
	615	if (local->ops->ampdu_action) {
	616	(void)local->ops->ampdu_action(hw,
	617	IEEE80211_AMPDU_TX_RESUME,
	618	&sta->sta, tid, &start_seq_num);
	619	}
	620	#ifdef CONFIG_MAC80211_HT_DEBUG
	621	printk(KERN_DEBUG "Resuming TX aggregation for tid %d\n", tid);
	622	#endif /* CONFIG_MAC80211_HT_DEBUG */
	623	spin_unlock_bh(&sta->lock);
	624	} else {
	625	sta->ampdu_mlme.addba_req_num[tid]++;
	626	/* this will allow the state check in stop_BA_session */
	627	*state = HT_AGG_STATE_OPERATIONAL;
	628	spin_unlock_bh(&sta->lock);
	629	ieee80211_stop_tx_ba_session(hw, sta->sta.addr, tid,
	630	WLAN_BACK_INITIATOR);
	631	}
	632	}