net/mac80211/ht.c - kernel/msm-4.9 - Gitiles

 /*
  * 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/export.h>
 #include <net/mac80211.h>
 #include "ieee80211_i.h"
 #include "rate.h"

 static void __check_htcap_disable(struct ieee80211_sub_if_data *sdata,
 				  struct ieee80211_sta_ht_cap *ht_cap,
 				  u16 flag)
 {
 	__le16 le_flag = cpu_to_le16(flag);
 	if (sdata->u.mgd.ht_capa_mask.cap_info & le_flag) {
 		if (!(sdata->u.mgd.ht_capa.cap_info & le_flag))
 			ht_cap->cap &= ~flag;
 	}
 }

 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
 				     struct ieee80211_sta_ht_cap *ht_cap)
 {
 	u8 *scaps = (u8 *)(&sdata->u.mgd.ht_capa.mcs.rx_mask);
 	u8 *smask = (u8 *)(&sdata->u.mgd.ht_capa_mask.mcs.rx_mask);
 	int i;

 	if (!ht_cap->ht_supported)
 		return;

 	if (sdata->vif.type != NL80211_IFTYPE_STATION) {
 		/* AP interfaces call this code when adding new stations,
 		 * so just silently ignore non station interfaces.
 		 */
 		return;
 	}

 	/* NOTE:  If you add more over-rides here, update register_hw
 	 * ht_capa_mod_msk logic in main.c as well.
 	 * And, if this method can ever change ht_cap.ht_supported, fix
 	 * the check in ieee80211_add_ht_ie.
 	 */

 	/* check for HT over-rides, MCS rates first. */
 	for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
 		u8 m = smask[i];
 		ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
 		/* Add back rates that are supported */
 		ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
 	}

 	/* Force removal of HT-40 capabilities? */
 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SUP_WIDTH_20_40);
 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_40);

 	/* Allow user to disable SGI-20 (SGI-40 is handled above) */
 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_20);

 	/* Allow user to disable the max-AMSDU bit. */
 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_MAX_AMSDU);

 	/* Allow user to decrease AMPDU factor */
 	if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
 	    IEEE80211_HT_AMPDU_PARM_FACTOR) {
 		u8 n = sdata->u.mgd.ht_capa.ampdu_params_info
 			& IEEE80211_HT_AMPDU_PARM_FACTOR;
 		if (n < ht_cap->ampdu_factor)
 			ht_cap->ampdu_factor = n;
 	}

 	/* Allow the user to increase AMPDU density. */
 	if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
 	    IEEE80211_HT_AMPDU_PARM_DENSITY) {
 		u8 n = (sdata->u.mgd.ht_capa.ampdu_params_info &
 			IEEE80211_HT_AMPDU_PARM_DENSITY)
 			>> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
 		if (n > ht_cap->ampdu_density)
 			ht_cap->ampdu_density = n;
 	}
 }


 bool ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
 				       struct ieee80211_supported_band *sband,
 				       struct ieee80211_ht_cap *ht_cap_ie,
 				       struct sta_info *sta)
 {
 	struct ieee80211_sta_ht_cap ht_cap;
 	u8 ampdu_info, tx_mcs_set_cap;
 	int i, max_tx_streams;
 	bool changed;
 	enum ieee80211_sta_rx_bandwidth bw;

 	memset(&ht_cap, 0, sizeof(ht_cap));

 	if (!ht_cap_ie || !sband->ht_cap.ht_supported)
 		goto apply;

 	ht_cap.ht_supported = true;

 	/*
 	 * The bits listed in this expression should be
 	 * the same for the peer and us, if the station
 	 * advertises more then we can't use those thus
 	 * we mask them out.
 	 */
 	ht_cap.cap = le16_to_cpu(ht_cap_ie->cap_info) &
 		(sband->ht_cap.cap |
 		 ~(IEEE80211_HT_CAP_LDPC_CODING |
 		   IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
 		   IEEE80211_HT_CAP_GRN_FLD |
 		   IEEE80211_HT_CAP_SGI_20 |
 		   IEEE80211_HT_CAP_SGI_40 |
 		   IEEE80211_HT_CAP_DSSSCCK40));

 	/*
 	 * The STBC bits are asymmetric -- if we don't have
 	 * TX then mask out the peer's RX and vice versa.
 	 */
 	if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_TX_STBC))
 		ht_cap.cap &= ~IEEE80211_HT_CAP_RX_STBC;
 	if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC))
 		ht_cap.cap &= ~IEEE80211_HT_CAP_TX_STBC;

 	ampdu_info = ht_cap_ie->ampdu_params_info;
 	ht_cap.ampdu_factor =
 		ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
 	ht_cap.ampdu_density =
 		(ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;

 	/* own MCS TX capabilities */
 	tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;

 	/* Copy peer MCS TX capabilities, the driver might need them. */
 	ht_cap.mcs.tx_params = ht_cap_ie->mcs.tx_params;

 	/* can we TX with MCS rates? */
 	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
 		goto apply;

 	/* Counting from 0, therefore +1 */
 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
 		max_tx_streams =
 			((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
 				>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
 	else
 		max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;

 	/*
 	 * 802.11n-2009 20.3.5 / 20.6 says:
 	 * - indices 0 to 7 and 32 are single spatial stream
 	 * - 8 to 31 are multiple spatial streams using equal modulation
 	 *   [8..15 for two streams, 16..23 for three and 24..31 for four]
 	 * - remainder are multiple spatial streams using unequal modulation
 	 */
 	for (i = 0; i < max_tx_streams; i++)
 		ht_cap.mcs.rx_mask[i] =
 			sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];

 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
 		for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
 		     i < IEEE80211_HT_MCS_MASK_LEN; i++)
 			ht_cap.mcs.rx_mask[i] =
 				sband->ht_cap.mcs.rx_mask[i] &
 					ht_cap_ie->mcs.rx_mask[i];

 	/* handle MCS rate 32 too */
 	if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
 		ht_cap.mcs.rx_mask[32/8] |= 1;

  apply:
 	/*
 	 * If user has specified capability over-rides, take care
 	 * of that here.
 	 */
 	ieee80211_apply_htcap_overrides(sdata, &ht_cap);

 	changed = memcmp(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));

 	memcpy(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));

 	switch (sdata->vif.bss_conf.chandef.width) {
 	default:
 		WARN_ON_ONCE(1);
 		/* fall through */
 	case NL80211_CHAN_WIDTH_20_NOHT:
 	case NL80211_CHAN_WIDTH_20:
 		bw = IEEE80211_STA_RX_BW_20;
 		break;
 	case NL80211_CHAN_WIDTH_40:
 	case NL80211_CHAN_WIDTH_80:
 	case NL80211_CHAN_WIDTH_80P80:
 	case NL80211_CHAN_WIDTH_160:
 		bw = ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
 				IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
 		break;
 	}

 	if (bw != sta->sta.bandwidth)
 		changed = true;
 	sta->sta.bandwidth = bw;

 	sta->cur_max_bandwidth =
 		ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
 				IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;

 	return changed;
 }

 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
 					 enum ieee80211_agg_stop_reason reason)
 {
 	int i;

 	cancel_work_sync(&sta->ampdu_mlme.work);

 	for (i = 0; i <  IEEE80211_NUM_TIDS; i++) {
 		__ieee80211_stop_tx_ba_session(sta, i, reason);
 		__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
 					       WLAN_REASON_QSTA_LEAVE_QBSS,
 					       reason != AGG_STOP_DESTROY_STA &&
 					       reason != AGG_STOP_PEER_REQUEST);
 	}
 }

 void ieee80211_ba_session_work(struct work_struct *work)
 {
 	struct sta_info *sta =
 		container_of(work, struct sta_info, ampdu_mlme.work);
 	struct tid_ampdu_tx *tid_tx;
 	int tid;

 	/*
 	 * When this flag is set, new sessions should be
 	 * blocked, and existing sessions will be torn
 	 * down by the code that set the flag, so this
 	 * need not run.
 	 */
 	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
 		return;

 	mutex_lock(&sta->ampdu_mlme.mtx);
 	for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
 		if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
 			___ieee80211_stop_rx_ba_session(
 				sta, tid, WLAN_BACK_RECIPIENT,
 				WLAN_REASON_QSTA_TIMEOUT, true);

 		if (test_and_clear_bit(tid,
 				       sta->ampdu_mlme.tid_rx_stop_requested))
 			___ieee80211_stop_rx_ba_session(
 				sta, tid, WLAN_BACK_RECIPIENT,
 				WLAN_REASON_UNSPECIFIED, true);

 		tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
 		if (tid_tx) {
 			/*
 			 * Assign it over to the normal tid_tx array
 			 * where it "goes live".
 			 */
 			spin_lock_bh(&sta->lock);

 			sta->ampdu_mlme.tid_start_tx[tid] = NULL;
 			/* could there be a race? */
 			if (sta->ampdu_mlme.tid_tx[tid])
 				kfree(tid_tx);
 			else
 				ieee80211_assign_tid_tx(sta, tid, tid_tx);
 			spin_unlock_bh(&sta->lock);

 			ieee80211_tx_ba_session_handle_start(sta, tid);
 			continue;
 		}

 		tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 		if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
 						 &tid_tx->state))
 			___ieee80211_stop_tx_ba_session(sta, tid,
 							AGG_STOP_LOCAL_REQUEST);
 	}
 	mutex_unlock(&sta->ampdu_mlme.mtx);
 }

 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
 			  const u8 *da, u16 tid,
 			  u16 initiator, u16 reason_code)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct sk_buff *skb;
 	struct ieee80211_mgmt *mgmt;
 	u16 params;

 	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.delba));

 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
 	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
 	params = (u16)(initiator << 11); 	/* bit 11 initiator */
 	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */

 	mgmt->u.action.u.delba.params = cpu_to_le16(params);
 	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);

 	ieee80211_tx_skb_tid(sdata, skb, tid);
 }

 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
 			     struct sta_info *sta,
 			     struct ieee80211_mgmt *mgmt, size_t len)
 {
 	u16 tid, params;
 	u16 initiator;

 	params = le16_to_cpu(mgmt->u.action.u.delba.params);
 	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
 	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;

 	ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
 			   mgmt->sa, initiator ? "initiator" : "recipient",
 			   tid,
 			   le16_to_cpu(mgmt->u.action.u.delba.reason_code));

 	if (initiator == WLAN_BACK_INITIATOR)
 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
 					       true);
 	else
 		__ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
 }

 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
 			       enum ieee80211_smps_mode smps, const u8 *da,
 			       const u8 *bssid)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct sk_buff *skb;
 	struct ieee80211_mgmt *action_frame;

 	/* 27 = header + category + action + smps mode */
 	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
 	if (!skb)
 		return -ENOMEM;

 	skb_reserve(skb, local->hw.extra_tx_headroom);
 	action_frame = (void *)skb_put(skb, 27);
 	memcpy(action_frame->da, da, ETH_ALEN);
 	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
 	memcpy(action_frame->bssid, bssid, ETH_ALEN);
 	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 						  IEEE80211_STYPE_ACTION);
 	action_frame->u.action.category = WLAN_CATEGORY_HT;
 	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
 	switch (smps) {
 	case IEEE80211_SMPS_AUTOMATIC:
 	case IEEE80211_SMPS_NUM_MODES:
 		WARN_ON(1);
 	case IEEE80211_SMPS_OFF:
 		action_frame->u.action.u.ht_smps.smps_control =
 				WLAN_HT_SMPS_CONTROL_DISABLED;
 		break;
 	case IEEE80211_SMPS_STATIC:
 		action_frame->u.action.u.ht_smps.smps_control =
 				WLAN_HT_SMPS_CONTROL_STATIC;
 		break;
 	case IEEE80211_SMPS_DYNAMIC:
 		action_frame->u.action.u.ht_smps.smps_control =
 				WLAN_HT_SMPS_CONTROL_DYNAMIC;
 		break;
 	}

 	/* we'll do more on status of this frame */
 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 	ieee80211_tx_skb(sdata, skb);

 	return 0;
 }

 void ieee80211_request_smps_work(struct work_struct *work)
 {
 	struct ieee80211_sub_if_data *sdata =
 		container_of(work, struct ieee80211_sub_if_data,
 			     u.mgd.request_smps_work);

 	mutex_lock(&sdata->u.mgd.mtx);
 	__ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
 	mutex_unlock(&sdata->u.mgd.mtx);
 }

 void ieee80211_request_smps(struct ieee80211_vif *vif,
 			    enum ieee80211_smps_mode smps_mode)
 {
 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);

 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
 		return;

 	if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
 		smps_mode = IEEE80211_SMPS_AUTOMATIC;

 	if (sdata->u.mgd.driver_smps_mode == smps_mode)
 		return;

 	sdata->u.mgd.driver_smps_mode = smps_mode;

 	ieee80211_queue_work(&sdata->local->hw,
 			     &sdata->u.mgd.request_smps_work);
 }
 /* this might change ... don't want non-open drivers using it */
 EXPORT_SYMBOL_GPL(ieee80211_request_smps);
	/*
	* 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/export.h>
	#include <net/mac80211.h>
	#include "ieee80211_i.h"
	#include "rate.h"

	static void __check_htcap_disable(struct ieee80211_sub_if_data *sdata,
	struct ieee80211_sta_ht_cap *ht_cap,
	u16 flag)
	{
	__le16 le_flag = cpu_to_le16(flag);
	if (sdata->u.mgd.ht_capa_mask.cap_info & le_flag) {
	if (!(sdata->u.mgd.ht_capa.cap_info & le_flag))
	ht_cap->cap &= ~flag;
	}
	}

	void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
	struct ieee80211_sta_ht_cap *ht_cap)
	{
	u8 scaps = (u8 )(&sdata->u.mgd.ht_capa.mcs.rx_mask);
	u8 smask = (u8 )(&sdata->u.mgd.ht_capa_mask.mcs.rx_mask);
	int i;

	if (!ht_cap->ht_supported)
	return;

	if (sdata->vif.type != NL80211_IFTYPE_STATION) {
	/* AP interfaces call this code when adding new stations,
	* so just silently ignore non station interfaces.
	*/
	return;
	}

	/* NOTE: If you add more over-rides here, update register_hw
	* ht_capa_mod_msk logic in main.c as well.
	* And, if this method can ever change ht_cap.ht_supported, fix
	* the check in ieee80211_add_ht_ie.
	*/

	/* check for HT over-rides, MCS rates first. */
	for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
	u8 m = smask[i];
	ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
	/* Add back rates that are supported */
	ht_cap->mcs.rx_mask[i] \|= (m & scaps[i]);
	}

	/* Force removal of HT-40 capabilities? */
	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SUP_WIDTH_20_40);
	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_40);

	/* Allow user to disable SGI-20 (SGI-40 is handled above) */
	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_20);

	/* Allow user to disable the max-AMSDU bit. */
	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_MAX_AMSDU);

	/* Allow user to decrease AMPDU factor */
	if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
	IEEE80211_HT_AMPDU_PARM_FACTOR) {
	u8 n = sdata->u.mgd.ht_capa.ampdu_params_info
	& IEEE80211_HT_AMPDU_PARM_FACTOR;
	if (n < ht_cap->ampdu_factor)
	ht_cap->ampdu_factor = n;
	}

	/* Allow the user to increase AMPDU density. */
	if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
	IEEE80211_HT_AMPDU_PARM_DENSITY) {
	u8 n = (sdata->u.mgd.ht_capa.ampdu_params_info &
	IEEE80211_HT_AMPDU_PARM_DENSITY)
	>> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
	if (n > ht_cap->ampdu_density)
	ht_cap->ampdu_density = n;
	}
	}


	bool ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
	struct ieee80211_supported_band *sband,
	struct ieee80211_ht_cap *ht_cap_ie,
	struct sta_info *sta)
	{
	struct ieee80211_sta_ht_cap ht_cap;
	u8 ampdu_info, tx_mcs_set_cap;
	int i, max_tx_streams;
	bool changed;
	enum ieee80211_sta_rx_bandwidth bw;

	memset(&ht_cap, 0, sizeof(ht_cap));

	if (!ht_cap_ie \|\| !sband->ht_cap.ht_supported)
	goto apply;

	ht_cap.ht_supported = true;

	/*
	* The bits listed in this expression should be
	* the same for the peer and us, if the station
	* advertises more then we can't use those thus
	* we mask them out.
	*/
	ht_cap.cap = le16_to_cpu(ht_cap_ie->cap_info) &
	(sband->ht_cap.cap \|
	~(IEEE80211_HT_CAP_LDPC_CODING \|
	IEEE80211_HT_CAP_SUP_WIDTH_20_40 \|
	IEEE80211_HT_CAP_GRN_FLD \|
	IEEE80211_HT_CAP_SGI_20 \|
	IEEE80211_HT_CAP_SGI_40 \|
	IEEE80211_HT_CAP_DSSSCCK40));

	/*
	* The STBC bits are asymmetric -- if we don't have
	* TX then mask out the peer's RX and vice versa.
	*/
	if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_TX_STBC))
	ht_cap.cap &= ~IEEE80211_HT_CAP_RX_STBC;
	if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC))
	ht_cap.cap &= ~IEEE80211_HT_CAP_TX_STBC;

	ampdu_info = ht_cap_ie->ampdu_params_info;
	ht_cap.ampdu_factor =
	ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
	ht_cap.ampdu_density =
	(ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;

	/* own MCS TX capabilities */
	tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;

	/* Copy peer MCS TX capabilities, the driver might need them. */
	ht_cap.mcs.tx_params = ht_cap_ie->mcs.tx_params;

	/* can we TX with MCS rates? */
	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
	goto apply;

	/* Counting from 0, therefore +1 */
	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
	max_tx_streams =
	((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
	>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
	else
	max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;

	/*
	* 802.11n-2009 20.3.5 / 20.6 says:
	* - indices 0 to 7 and 32 are single spatial stream
	* - 8 to 31 are multiple spatial streams using equal modulation
	* [8..15 for two streams, 16..23 for three and 24..31 for four]
	* - remainder are multiple spatial streams using unequal modulation
	*/
	for (i = 0; i < max_tx_streams; i++)
	ht_cap.mcs.rx_mask[i] =
	sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];

	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
	for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
	i < IEEE80211_HT_MCS_MASK_LEN; i++)
	ht_cap.mcs.rx_mask[i] =
	sband->ht_cap.mcs.rx_mask[i] &
	ht_cap_ie->mcs.rx_mask[i];

	/* handle MCS rate 32 too */
	if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
	ht_cap.mcs.rx_mask[32/8] \|= 1;

	apply:
	/*
	* If user has specified capability over-rides, take care
	* of that here.
	*/
	ieee80211_apply_htcap_overrides(sdata, &ht_cap);

	changed = memcmp(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));

	memcpy(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));

	switch (sdata->vif.bss_conf.chandef.width) {
	default:
	WARN_ON_ONCE(1);
	/* fall through */
	case NL80211_CHAN_WIDTH_20_NOHT:
	case NL80211_CHAN_WIDTH_20:
	bw = IEEE80211_STA_RX_BW_20;
	break;
	case NL80211_CHAN_WIDTH_40:
	case NL80211_CHAN_WIDTH_80:
	case NL80211_CHAN_WIDTH_80P80:
	case NL80211_CHAN_WIDTH_160:
	bw = ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
	IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
	break;
	}

	if (bw != sta->sta.bandwidth)
	changed = true;
	sta->sta.bandwidth = bw;

	sta->cur_max_bandwidth =
	ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
	IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;

	return changed;
	}

	void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
	enum ieee80211_agg_stop_reason reason)
	{
	int i;

	cancel_work_sync(&sta->ampdu_mlme.work);

	for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
	__ieee80211_stop_tx_ba_session(sta, i, reason);
	__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
	WLAN_REASON_QSTA_LEAVE_QBSS,
	reason != AGG_STOP_DESTROY_STA &&
	reason != AGG_STOP_PEER_REQUEST);
	}
	}

	void ieee80211_ba_session_work(struct work_struct *work)
	{
	struct sta_info *sta =
	container_of(work, struct sta_info, ampdu_mlme.work);
	struct tid_ampdu_tx *tid_tx;
	int tid;

	/*
	* When this flag is set, new sessions should be
	* blocked, and existing sessions will be torn
	* down by the code that set the flag, so this
	* need not run.
	*/
	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
	return;

	mutex_lock(&sta->ampdu_mlme.mtx);
	for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
	if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
	___ieee80211_stop_rx_ba_session(
	sta, tid, WLAN_BACK_RECIPIENT,
	WLAN_REASON_QSTA_TIMEOUT, true);

	if (test_and_clear_bit(tid,
	sta->ampdu_mlme.tid_rx_stop_requested))
	___ieee80211_stop_rx_ba_session(
	sta, tid, WLAN_BACK_RECIPIENT,
	WLAN_REASON_UNSPECIFIED, true);

	tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
	if (tid_tx) {
	/*
	* Assign it over to the normal tid_tx array
	* where it "goes live".
	*/
	spin_lock_bh(&sta->lock);

	sta->ampdu_mlme.tid_start_tx[tid] = NULL;
	/* could there be a race? */
	if (sta->ampdu_mlme.tid_tx[tid])
	kfree(tid_tx);
	else
	ieee80211_assign_tid_tx(sta, tid, tid_tx);
	spin_unlock_bh(&sta->lock);

	ieee80211_tx_ba_session_handle_start(sta, tid);
	continue;
	}

	tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
	if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
	&tid_tx->state))
	___ieee80211_stop_tx_ba_session(sta, tid,
	AGG_STOP_LOCAL_REQUEST);
	}
	mutex_unlock(&sta->ampdu_mlme.mtx);
	}

	void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
	const u8 *da, u16 tid,
	u16 initiator, u16 reason_code)
	{
	struct ieee80211_local *local = sdata->local;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u16 params;

	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.delba));

	mgmt->u.action.category = WLAN_CATEGORY_BACK;
	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
	params = (u16)(initiator << 11); /* bit 11 initiator */
	params \|= (u16)(tid << 12); /* bit 15:12 TID number */

	mgmt->u.action.u.delba.params = cpu_to_le16(params);
	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);

	ieee80211_tx_skb_tid(sdata, skb, tid);
	}

	void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
	struct sta_info *sta,
	struct ieee80211_mgmt *mgmt, size_t len)
	{
	u16 tid, params;
	u16 initiator;

	params = le16_to_cpu(mgmt->u.action.u.delba.params);
	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;

	ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
	mgmt->sa, initiator ? "initiator" : "recipient",
	tid,
	le16_to_cpu(mgmt->u.action.u.delba.reason_code));

	if (initiator == WLAN_BACK_INITIATOR)
	__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
	true);
	else
	__ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
	}

	int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
	enum ieee80211_smps_mode smps, const u8 *da,
	const u8 *bssid)
	{
	struct ieee80211_local *local = sdata->local;
	struct sk_buff *skb;
	struct ieee80211_mgmt *action_frame;

	/* 27 = header + category + action + smps mode */
	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
	if (!skb)
	return -ENOMEM;

	skb_reserve(skb, local->hw.extra_tx_headroom);
	action_frame = (void *)skb_put(skb, 27);
	memcpy(action_frame->da, da, ETH_ALEN);
	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
	memcpy(action_frame->bssid, bssid, ETH_ALEN);
	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT \|
	IEEE80211_STYPE_ACTION);
	action_frame->u.action.category = WLAN_CATEGORY_HT;
	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
	switch (smps) {
	case IEEE80211_SMPS_AUTOMATIC:
	case IEEE80211_SMPS_NUM_MODES:
	WARN_ON(1);
	case IEEE80211_SMPS_OFF:
	action_frame->u.action.u.ht_smps.smps_control =
	WLAN_HT_SMPS_CONTROL_DISABLED;
	break;
	case IEEE80211_SMPS_STATIC:
	action_frame->u.action.u.ht_smps.smps_control =
	WLAN_HT_SMPS_CONTROL_STATIC;
	break;
	case IEEE80211_SMPS_DYNAMIC:
	action_frame->u.action.u.ht_smps.smps_control =
	WLAN_HT_SMPS_CONTROL_DYNAMIC;
	break;
	}

	/* we'll do more on status of this frame */
	IEEE80211_SKB_CB(skb)->flags \|= IEEE80211_TX_CTL_REQ_TX_STATUS;
	ieee80211_tx_skb(sdata, skb);

	return 0;
	}

	void ieee80211_request_smps_work(struct work_struct *work)
	{
	struct ieee80211_sub_if_data *sdata =
	container_of(work, struct ieee80211_sub_if_data,
	u.mgd.request_smps_work);

	mutex_lock(&sdata->u.mgd.mtx);
	__ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
	mutex_unlock(&sdata->u.mgd.mtx);
	}

	void ieee80211_request_smps(struct ieee80211_vif *vif,
	enum ieee80211_smps_mode smps_mode)
	{
	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);

	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
	return;

	if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
	smps_mode = IEEE80211_SMPS_AUTOMATIC;

	if (sdata->u.mgd.driver_smps_mode == smps_mode)
	return;

	sdata->u.mgd.driver_smps_mode = smps_mode;

	ieee80211_queue_work(&sdata->local->hw,
	&sdata->u.mgd.request_smps_work);
	}
	/* this might change ... don't want non-open drivers using it */
	EXPORT_SYMBOL_GPL(ieee80211_request_smps);