text: /*
   * 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 2007-2008, 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 "rate.h"
  
  void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_supported_band *sband,
  				       struct ieee80211_ht_cap *ht_cap_ie,
  				       struct ieee80211_sta_ht_cap *ht_cap)
  {
  	u8 ampdu_info, tx_mcs_set_cap;
  	int i, max_tx_streams;
  
  	BUG_ON(!ht_cap);
  
  	memset(ht_cap, 0, sizeof(*ht_cap));
  
  	if (!ht_cap_ie)
  		return;
  
  	ht_cap->ht_supported = true;
  
  	ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info) & sband->ht_cap.cap;
  	ht_cap->cap &= ~IEEE80211_HT_CAP_SM_PS;
  	ht_cap->cap |= sband->ht_cap.cap & IEEE80211_HT_CAP_SM_PS;
  
  	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;
  
  	/* can we TX with MCS rates? */
  	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
  		return;
  
  	/* 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 D5.0 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;
  }
  
  void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta)
  {
  	int i;
  
  	for (i = 0; i <  STA_TID_NUM; i++) {
  		__ieee80211_stop_tx_ba_session(sta, i, WLAN_BACK_INITIATOR);
  		__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
  					       WLAN_REASON_QSTA_LEAVE_QBSS);
  	}
  }
  
  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) {
  		printk(KERN_ERR "%s: failed to allocate buffer "
  					"for delba 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 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.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(sdata, skb, 1);
  }
  
  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;
  
  #ifdef CONFIG_MAC80211_HT_DEBUG
  	if (net_ratelimit())
  		printk(KERN_DEBUG "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));
  #endif /* CONFIG_MAC80211_HT_DEBUG */
  
  	if (initiator == WLAN_BACK_INITIATOR)
  		ieee80211_sta_stop_rx_ba_session(sdata, sta->sta.addr, tid,
  						 WLAN_BACK_INITIATOR, 0);
  	else { /* WLAN_BACK_RECIPIENT */
  		spin_lock_bh(&sta->lock);
  		if (sta->ampdu_mlme.tid_state_tx[tid] & HT_ADDBA_REQUESTED_MSK)
  			___ieee80211_stop_tx_ba_session(sta, tid,
  							WLAN_BACK_RECIPIENT);
  		spin_unlock_bh(&sta->lock);
  	}
  }
  