[net-next-2.6.git] / net / mac80211 / agg-rx.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 2007-2010, 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.
 */

/**
 * DOC: RX A-MPDU aggregation
 *
 * Aggregation on the RX side requires only implementing the
 * @ampdu_action callback that is invoked to start/stop any
 * block-ack sessions for RX aggregation.
 *
 * When RX aggregation is started by the peer, the driver is
 * notified via @ampdu_action function, with the
 * %IEEE80211_AMPDU_RX_START action, and may reject the request
 * in which case a negative response is sent to the peer, if it
 * accepts it a positive response is sent.
 *
 * While the session is active, the device/driver are required
 * to de-aggregate frames and pass them up one by one to mac80211,
 * which will handle the reorder buffer.
 *
 * When the aggregation session is stopped again by the peer or
 * ourselves, the driver's @ampdu_action function will be called
 * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
 * call must not fail.
 */

#include <linux/ieee80211.h>
#include <linux/slab.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"

static void ieee80211_free_tid_rx(struct rcu_head *h)
{
	struct tid_ampdu_rx *tid_rx =
		container_of(h, struct tid_ampdu_rx, rcu_head);
	int i;

	for (i = 0; i < tid_rx->buf_size; i++)
		dev_kfree_skb(tid_rx->reorder_buf[i]);
	kfree(tid_rx->reorder_buf);
	kfree(tid_rx->reorder_time);
	kfree(tid_rx);
}

void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
				     u16 initiator, u16 reason)
{
	struct ieee80211_local *local = sta->local;
	struct tid_ampdu_rx *tid_rx;

	lockdep_assert_held(&sta->ampdu_mlme.mtx);

	tid_rx = sta->ampdu_mlme.tid_rx[tid];

	if (!tid_rx)
		return;

	rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], NULL);

#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
	       sta->sta.addr, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

	if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
			     &sta->sta, tid, NULL))
		printk(KERN_DEBUG "HW problem - can not stop rx "
				"aggregation for tid %d\n", tid);

	/* check if this is a self generated aggregation halt */
	if (initiator == WLAN_BACK_RECIPIENT)
		ieee80211_send_delba(sta->sdata, sta->sta.addr,
				     tid, 0, reason);

	del_timer_sync(&tid_rx->session_timer);

	call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
}

void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
				    u16 initiator, u16 reason)
{
	mutex_lock(&sta->ampdu_mlme.mtx);
	___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason);
	mutex_unlock(&sta->ampdu_mlme.mtx);
}

/*
 * After accepting the AddBA Request we activated a timer,
 * resetting it after each frame that arrives from the originator.
 */
static void sta_rx_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]);

#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
#endif
	set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
	ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
}

static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
				      u8 dialog_token, u16 status, u16 policy,
				      u16 buf_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) {
		printk(KERN_DEBUG "%s: failed to allocate buffer "
		       "for addba resp frame\n", sdata->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->vif.addr, ETH_ALEN);
	if (sdata->vif.type == NL80211_IFTYPE_AP ||
	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
		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);

	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					  IEEE80211_STYPE_ACTION);

	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
	mgmt->u.action.category = WLAN_CATEGORY_BACK;
	mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
	mgmt->u.action.u.addba_resp.dialog_token = dialog_token;

	capab = (u16)(policy << 1);	/* bit 1 aggregation policy */
	capab |= (u16)(tid << 2); 	/* bit 5:2 TID number */
	capab |= (u16)(buf_size << 6);	/* bit 15:6 max size of aggregation */

	mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
	mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
	mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);

	ieee80211_tx_skb(sdata, skb);
}

void ieee80211_process_addba_request(struct ieee80211_local *local,
				     struct sta_info *sta,
				     struct ieee80211_mgmt *mgmt,
				     size_t len)
{
	struct ieee80211_hw *hw = &local->hw;
	struct ieee80211_conf *conf = &hw->conf;
	struct tid_ampdu_rx *tid_agg_rx;
	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
	u8 dialog_token;
	int ret = -EOPNOTSUPP;

	/* extract session parameters from addba request frame */
	dialog_token = mgmt->u.action.u.addba_req.dialog_token;
	timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
	start_seq_num =
		le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;

	capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
	ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;

	status = WLAN_STATUS_REQUEST_DECLINED;

	if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Suspend in progress. "
		       "Denying ADDBA request\n");
#endif
		goto end_no_lock;
	}

	/* sanity check for incoming parameters:
	 * check if configuration can support the BA policy
	 * and if buffer size does not exceeds max value */
	/* XXX: check own ht delayed BA capability?? */
	if (((ba_policy != 1) &&
	     (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
	    (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
		status = WLAN_STATUS_INVALID_QOS_PARAM;
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_DEBUG "AddBA Req with bad params from "
				"%pM on tid %u. policy %d, buffer size %d\n",
				mgmt->sa, tid, ba_policy,
				buf_size);
#endif /* CONFIG_MAC80211_HT_DEBUG */
		goto end_no_lock;
	}
	/* determine default buffer size */
	if (buf_size == 0) {
		struct ieee80211_supported_band *sband;

		sband = local->hw.wiphy->bands[conf->channel->band];
		buf_size = IEEE80211_MIN_AMPDU_BUF;
		buf_size = buf_size << sband->ht_cap.ampdu_factor;
	}


	/* examine state machine */
	mutex_lock(&sta->ampdu_mlme.mtx);

	if (sta->ampdu_mlme.tid_rx[tid]) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_DEBUG "unexpected AddBA Req from "
				"%pM on tid %u\n",
				mgmt->sa, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
		goto end;
	}

	/* prepare A-MPDU MLME for Rx aggregation */
	tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
	if (!tid_agg_rx) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
					tid);
#endif
		goto end;
	}

	/* rx timer */
	tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
	tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
	init_timer(&tid_agg_rx->session_timer);

	/* prepare reordering buffer */
	tid_agg_rx->reorder_buf =
		kcalloc(buf_size, sizeof(struct sk_buff *), GFP_ATOMIC);
	tid_agg_rx->reorder_time =
		kcalloc(buf_size, sizeof(unsigned long), GFP_ATOMIC);
	if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_ERR "can not allocate reordering buffer "
			       "to tid %d\n", tid);
#endif
		kfree(tid_agg_rx->reorder_buf);
		kfree(tid_agg_rx->reorder_time);
		kfree(tid_agg_rx);
		goto end;
	}

	ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
			       &sta->sta, tid, &start_seq_num);
#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
#endif /* CONFIG_MAC80211_HT_DEBUG */

	if (ret) {
		kfree(tid_agg_rx->reorder_buf);
		kfree(tid_agg_rx->reorder_time);
		kfree(tid_agg_rx);
		goto end;
	}

	/* update data */
	tid_agg_rx->dialog_token = dialog_token;
	tid_agg_rx->ssn = start_seq_num;
	tid_agg_rx->head_seq_num = start_seq_num;
	tid_agg_rx->buf_size = buf_size;
	tid_agg_rx->timeout = timeout;
	tid_agg_rx->stored_mpdu_num = 0;
	status = WLAN_STATUS_SUCCESS;

	/* activate it for RX */
	rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);

	if (timeout)
		mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));

end:
	mutex_unlock(&sta->ampdu_mlme.mtx);

end_no_lock:
	ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
				  dialog_token, status, 1, buf_size, timeout);
}
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>
a93e3644	9	* Copyright 2007-2010, Intel Corporation
b8695a8f JB	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
73a72a81 JB	16	/**
	17	* DOC: RX A-MPDU aggregation
	18	*
	19	* Aggregation on the RX side requires only implementing the
	20	* @ampdu_action callback that is invoked to start/stop any
	21	* block-ack sessions for RX aggregation.
	22	*
	23	* When RX aggregation is started by the peer, the driver is
	24	* notified via @ampdu_action function, with the
	25	* %IEEE80211_AMPDU_RX_START action, and may reject the request
	26	* in which case a negative response is sent to the peer, if it
	27	* accepts it a positive response is sent.
	28	*
	29	* While the session is active, the device/driver are required
	30	* to de-aggregate frames and pass them up one by one to mac80211,
	31	* which will handle the reorder buffer.
	32	*
	33	* When the aggregation session is stopped again by the peer or
	34	* ourselves, the driver's @ampdu_action function will be called
	35	* with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
	36	* call must not fail.
	37	*/
	38
b8695a8f	39	#include <linux/ieee80211.h>
5a0e3ad6	40	#include <linux/slab.h>
b8695a8f JB	41	#include <net/mac80211.h>
b8695a8f JB	42	#include "ieee80211_i.h"
24487981	43	#include "driver-ops.h"
b8695a8f	44
a87f736d JB	45	static void ieee80211_free_tid_rx(struct rcu_head *h)
	46	{
	47	struct tid_ampdu_rx *tid_rx =
	48	container_of(h, struct tid_ampdu_rx, rcu_head);
	49	int i;
	50
	51	for (i = 0; i < tid_rx->buf_size; i++)
	52	dev_kfree_skb(tid_rx->reorder_buf[i]);
	53	kfree(tid_rx->reorder_buf);
	54	kfree(tid_rx->reorder_time);
	55	kfree(tid_rx);
	56	}
	57
7c3b1dd8 JB	58	void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
7c3b1dd8 JB	59	u16 initiator, u16 reason)
b8695a8f	60	{
d75636ef	61	struct ieee80211_local *local = sta->local;
098a6070	62	struct tid_ampdu_rx *tid_rx;
b8695a8f	63
a93e3644	64	lockdep_assert_held(&sta->ampdu_mlme.mtx);
098a6070	65
a87f736d JB	66	tid_rx = sta->ampdu_mlme.tid_rx[tid];
a87f736d JB	67
7c3b1dd8	68	if (!tid_rx)
b8695a8f	69	return;
d75636ef	70
a87f736d	71	rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], NULL);
b8695a8f	72
b8695a8f JB	73	#ifdef CONFIG_MAC80211_HT_DEBUG
b8695a8f JB	74	printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
d75636ef	75	sta->sta.addr, tid);
b8695a8f JB	76	#endif /* CONFIG_MAC80211_HT_DEBUG */
b8695a8f JB	77
12375ef9	78	if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
24487981	79	&sta->sta, tid, NULL))
b8695a8f JB	80	printk(KERN_DEBUG "HW problem - can not stop rx "
	81	"aggregation for tid %d\n", tid);
	82
b8695a8f	83	/* check if this is a self generated aggregation halt */
098a6070	84	if (initiator == WLAN_BACK_RECIPIENT)
d75636ef JB	85	ieee80211_send_delba(sta->sdata, sta->sta.addr,
d75636ef JB	86	tid, 0, reason);
b8695a8f	87
7c3b1dd8	88	del_timer_sync(&tid_rx->session_timer);
a87f736d JB	89
a87f736d JB	90	call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
b8695a8f JB	91	}
b8695a8f JB	92
2aab4c27 JB	93	void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
	94	u16 initiator, u16 reason)
	95	{
a93e3644	96	mutex_lock(&sta->ampdu_mlme.mtx);
7c3b1dd8	97	___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason);
a93e3644	98	mutex_unlock(&sta->ampdu_mlme.mtx);
2aab4c27 JB	99	}
2aab4c27 JB	100
b8695a8f JB	101	/*
	102	* After accepting the AddBA Request we activated a timer,
	103	* resetting it after each frame that arrives from the originator.
b8695a8f JB	104	*/
	105	static void sta_rx_agg_session_timer_expired(unsigned long data)
	106	{
	107	/* not an elegant detour, but there is no choice as the timer passes
	108	* only one argument, and various sta_info are needed here, so init
	109	* flow in sta_info_create gives the TID as data, while the timer_to_id
	110	* array gives the sta through container_of */
	111	u8 ptid = (u8 )data;
	112	u8 timer_to_id = ptid - ptid;
	113	struct sta_info *sta = container_of(timer_to_id, struct sta_info,
	114	timer_to_tid[0]);
	115
	116	#ifdef CONFIG_MAC80211_HT_DEBUG
	117	printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
	118	#endif
7c3b1dd8 JB	119	set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
7c3b1dd8 JB	120	ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
b8695a8f JB	121	}
	122
	123	static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data sdata, u8 da, u16 tid,
	124	u8 dialog_token, u16 status, u16 policy,
	125	u16 buf_size, u16 timeout)
	126	{
b8695a8f JB	127	struct ieee80211_local *local = sdata->local;
	128	struct sk_buff *skb;
	129	struct ieee80211_mgmt *mgmt;
	130	u16 capab;
	131
	132	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
	133
	134	if (!skb) {
	135	printk(KERN_DEBUG "%s: failed to allocate buffer "
47846c9b	136	"for addba resp frame\n", sdata->name);
b8695a8f JB	137	return;
	138	}
	139
	140	skb_reserve(skb, local->hw.extra_tx_headroom);
	141	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
	142	memset(mgmt, 0, 24);
	143	memcpy(mgmt->da, da, ETH_ALEN);
47846c9b	144	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
8abd3f9b JB	145	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
8abd3f9b JB	146	sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
47846c9b	147	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
46900298 JB	148	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
	149	memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
	150
b8695a8f JB	151	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT \|
	152	IEEE80211_STYPE_ACTION);
	153
	154	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
	155	mgmt->u.action.category = WLAN_CATEGORY_BACK;
	156	mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
	157	mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
	158
	159	capab = (u16)(policy << 1); /* bit 1 aggregation policy */
	160	capab \|= (u16)(tid << 2); /* bit 5:2 TID number */
	161	capab \|= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */
	162
	163	mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
	164	mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
	165	mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
	166
62ae67be	167	ieee80211_tx_skb(sdata, skb);
b8695a8f JB	168	}
	169
	170	void ieee80211_process_addba_request(struct ieee80211_local *local,
	171	struct sta_info *sta,
	172	struct ieee80211_mgmt *mgmt,
	173	size_t len)
	174	{
	175	struct ieee80211_hw *hw = &local->hw;
	176	struct ieee80211_conf *conf = &hw->conf;
	177	struct tid_ampdu_rx *tid_agg_rx;
	178	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
	179	u8 dialog_token;
	180	int ret = -EOPNOTSUPP;
	181
	182	/* extract session parameters from addba request frame */
	183	dialog_token = mgmt->u.action.u.addba_req.dialog_token;
	184	timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
	185	start_seq_num =
	186	le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
	187
	188	capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
	189	ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
	190	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
	191	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
	192
	193	status = WLAN_STATUS_REQUEST_DECLINED;
	194
618f356b	195	if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
722f069a S	196	#ifdef CONFIG_MAC80211_HT_DEBUG
	197	printk(KERN_DEBUG "Suspend in progress. "
	198	"Denying ADDBA request\n");
	199	#endif
	200	goto end_no_lock;
	201	}
	202
b8695a8f JB	203	/* sanity check for incoming parameters:
	204	* check if configuration can support the BA policy
	205	* and if buffer size does not exceeds max value */
	206	/* XXX: check own ht delayed BA capability?? */
f64f9e71 JP	207	if (((ba_policy != 1) &&
	208	(!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) \|\|
	209	(buf_size > IEEE80211_MAX_AMPDU_BUF)) {
b8695a8f JB	210	status = WLAN_STATUS_INVALID_QOS_PARAM;
	211	#ifdef CONFIG_MAC80211_HT_DEBUG
	212	if (net_ratelimit())
	213	printk(KERN_DEBUG "AddBA Req with bad params from "
	214	"%pM on tid %u. policy %d, buffer size %d\n",
	215	mgmt->sa, tid, ba_policy,
	216	buf_size);
	217	#endif /* CONFIG_MAC80211_HT_DEBUG */
	218	goto end_no_lock;
	219	}
	220	/* determine default buffer size */
	221	if (buf_size == 0) {
	222	struct ieee80211_supported_band *sband;
	223
	224	sband = local->hw.wiphy->bands[conf->channel->band];
	225	buf_size = IEEE80211_MIN_AMPDU_BUF;
	226	buf_size = buf_size << sband->ht_cap.ampdu_factor;
	227	}
	228
	229
	230	/* examine state machine */
a93e3644	231	mutex_lock(&sta->ampdu_mlme.mtx);
b8695a8f	232
a87f736d	233	if (sta->ampdu_mlme.tid_rx[tid]) {
b8695a8f JB	234	#ifdef CONFIG_MAC80211_HT_DEBUG
	235	if (net_ratelimit())
	236	printk(KERN_DEBUG "unexpected AddBA Req from "
	237	"%pM on tid %u\n",
	238	mgmt->sa, tid);
	239	#endif /* CONFIG_MAC80211_HT_DEBUG */
	240	goto end;
	241	}
	242
	243	/* prepare A-MPDU MLME for Rx aggregation */
a87f736d JB	244	tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
a87f736d JB	245	if (!tid_agg_rx) {
b8695a8f JB	246	#ifdef CONFIG_MAC80211_HT_DEBUG
	247	if (net_ratelimit())
	248	printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
	249	tid);
	250	#endif
	251	goto end;
	252	}
b8695a8f	253
a87f736d JB	254	/* rx timer */
	255	tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
	256	tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
	257	init_timer(&tid_agg_rx->session_timer);
b8695a8f JB	258
	259	/* prepare reordering buffer */
	260	tid_agg_rx->reorder_buf =
	261	kcalloc(buf_size, sizeof(struct sk_buff *), GFP_ATOMIC);
4d050f1d JM	262	tid_agg_rx->reorder_time =
	263	kcalloc(buf_size, sizeof(unsigned long), GFP_ATOMIC);
	264	if (!tid_agg_rx->reorder_buf \|\| !tid_agg_rx->reorder_time) {
b8695a8f JB	265	#ifdef CONFIG_MAC80211_HT_DEBUG
	266	if (net_ratelimit())
	267	printk(KERN_ERR "can not allocate reordering buffer "
	268	"to tid %d\n", tid);
	269	#endif
4d050f1d JM	270	kfree(tid_agg_rx->reorder_buf);
4d050f1d JM	271	kfree(tid_agg_rx->reorder_time);
a87f736d	272	kfree(tid_agg_rx);
b8695a8f JB	273	goto end;
	274	}
	275
12375ef9	276	ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
24487981	277	&sta->sta, tid, &start_seq_num);
b8695a8f JB	278	#ifdef CONFIG_MAC80211_HT_DEBUG
	279	printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
	280	#endif /* CONFIG_MAC80211_HT_DEBUG */
	281
	282	if (ret) {
	283	kfree(tid_agg_rx->reorder_buf);
a87f736d	284	kfree(tid_agg_rx->reorder_time);
b8695a8f	285	kfree(tid_agg_rx);
b8695a8f JB	286	goto end;
	287	}
	288
a87f736d	289	/* update data */
b8695a8f JB	290	tid_agg_rx->dialog_token = dialog_token;
	291	tid_agg_rx->ssn = start_seq_num;
	292	tid_agg_rx->head_seq_num = start_seq_num;
	293	tid_agg_rx->buf_size = buf_size;
	294	tid_agg_rx->timeout = timeout;
	295	tid_agg_rx->stored_mpdu_num = 0;
	296	status = WLAN_STATUS_SUCCESS;
a87f736d JB	297
	298	/* activate it for RX */
	299	rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
f955ebb4 JB	300
	301	if (timeout)
	302	mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
	303
b8695a8f	304	end:
a93e3644	305	mutex_unlock(&sta->ampdu_mlme.mtx);
b8695a8f JB	306
	307	end_no_lock:
	308	ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
	309	dialog_token, status, 1, buf_size, timeout);
	310	}