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|
/*
* 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 "driver-ops.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 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 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_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);
}
static int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
enum ieee80211_back_parties initiator)
{
struct ieee80211_local *local = sta->local;
int ret;
u8 *state;
state = &sta->ampdu_mlme.tid_state_tx[tid];
if (*state == HT_AGG_STATE_OPERATIONAL)
sta->ampdu_mlme.addba_req_num[tid] = 0;
*state = HT_AGG_STATE_REQ_STOP_BA_MSK |
(initiator << HT_AGG_STATE_INITIATOR_SHIFT);
ret = drv_ampdu_action(local, &sta->sdata->vif,
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;
/*
* We may have pending packets get stuck in this case...
* Not bothering with a workaround for now.
*/
}
return ret;
}
/*
* After sending add Block Ack request we activated a timer until
* add Block Ack response will arrive from the recipient.
* If this timer expires sta_addba_resp_timer_expired will be executed.
*/
static void sta_addba_resp_timer_expired(unsigned long data)
{
/* not an elegant detour, but there is no choice as the timer passes
* only one argument, and both sta_info and TID are needed, so init
* flow in sta_info_create gives the TID as data, while the timer_to_id
* array gives the sta through container_of */
u16 tid = *(u8 *)data;
struct sta_info *sta = container_of((void *)data,
struct sta_info, timer_to_tid[tid]);
u8 *state;
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
return;
}
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
#endif
___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BA
|