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mac80211: A-MPDU Tx adding basic functionality
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This patch adds the following abilities to mac80211:
 - start A-MPDU Tx session
 - stop A-MPDU Tx session
 - call backs to start/stop A-MPDU Tx session
 - sending addBA request
 - processing addBA response

Signed-off-by: Ron Rindjunsky <ron.rindjunsky@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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Ron Rindjunsky authored and John W. Linville committed Feb 29, 2008
1 parent 80656c2 commit eadc8d9
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Showing 3 changed files with 530 additions and 2 deletions.
336 changes: 336 additions & 0 deletions net/mac80211/ieee80211.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -414,6 +414,329 @@ static int ieee80211_stop(struct net_device *dev)
return 0;
}

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 = 0;
u8 *state;
int ret;
DECLARE_MAC_BUF(mac);

if (tid >= STA_TID_NUM)
return -EINVAL;

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

sta = sta_info_get(local, ra);
if (!sta) {
printk(KERN_DEBUG "Could not find the station\n");
return -ENOENT;
}

spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);

/* we have tried too many times, receiver does not want A-MPDU */
if (sta->ampdu_mlme.tid_tx[tid].addba_req_num > HT_AGG_MAX_RETRIES) {
ret = -EBUSY;
goto start_ba_exit;
}

state = &sta->ampdu_mlme.tid_tx[tid].state;
/* 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 start_ba_exit;
}

/* ensure that TX flow won't interrupt us
* until the end of the call to requeue function */
spin_lock_bh(&local->mdev->queue_lock);

/* 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 - no queue available for"
" tid %d\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
spin_unlock_bh(&local->mdev->queue_lock);
goto start_ba_exit;
}
sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);

/* 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;

if (local->ops->ampdu_action)
ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_START,
ra, 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 */
/* ieee80211_ht_agg_queue_remove(local, sta, tid, 0); */
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "BA request denied - HW or queue unavailable"
" for tid %d\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
spin_unlock_bh(&local->mdev->queue_lock);
*state = HT_AGG_STATE_IDLE;
goto start_ba_exit;
}

/* Will put all the packets in the new SW queue */
/* ieee80211_requeue(local, ieee802_1d_to_ac[tid]); */
spin_unlock_bh(&local->mdev->queue_lock);

/* We have most probably almost emptied the legacy queue */
/* ieee80211_wake_queue(local_to_hw(local), ieee802_1d_to_ac[tid]); */

/* 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->dev, 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);
printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);

start_ba_exit:
spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
sta_info_put(sta);
return ret;
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_session);

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;
DECLARE_MAC_BUF(mac);

if (tid >= STA_TID_NUM)
return -EINVAL;

#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Stop a BA session requested for %s tid %u\n",
print_mac(mac, ra), tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

sta = sta_info_get(local, ra);
if (!sta)
return -ENOENT;

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

if (*state != HT_AGG_STATE_OPERATIONAL) {
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Try to stop Tx aggregation on"
" non active TID\n");
#endif /* CONFIG_MAC80211_HT_DEBUG */
ret = -ENOENT;
goto stop_BA_exit;
}

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,
ra, tid, NULL);

/* case HW denied going back to legacy */
if (ret) {
WARN_ON(ret != -EBUSY);
*state = HT_AGG_STATE_OPERATIONAL;
ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
goto stop_BA_exit;
}

stop_BA_exit:
spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
sta_info_put(sta);
return ret;
}
EXPORT_SYMBOL(ieee80211_stop_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;
DECLARE_MAC_BUF(mac);

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

sta = sta_info_get(local, ra);
if (!sta) {
printk(KERN_DEBUG "Could not find station: %s\n",
print_mac(mac, ra));
return;
}

state = &sta->ampdu_mlme.tid_tx[tid].state;
spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);

if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
*state);
spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
sta_info_put(sta);
return;
}

WARN_ON_ONCE(*state & HT_ADDBA_DRV_READY_MSK);

*state |= HT_ADDBA_DRV_READY_MSK;

if (*state == HT_AGG_STATE_OPERATIONAL) {
printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
}
spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
sta_info_put(sta);
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);

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;
DECLARE_MAC_BUF(mac);

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

printk(KERN_DEBUG "Stop a BA session requested on DA %s tid %d\n",
print_mac(mac, ra), tid);

sta = sta_info_get(local, ra);
if (!sta) {
printk(KERN_DEBUG "Could not find station: %s\n",
print_mac(mac, ra));
return;
}
state = &sta->ampdu_mlme.tid_tx[tid].state;

spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
sta_info_put(sta);
spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
return;
}

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

agg_queue = sta->tid_to_tx_q[tid];

/* avoid ordering issues: we are the only one that can modify
* the content of the qdiscs */
spin_lock_bh(&local->mdev->queue_lock);
/* remove the queue for this aggregation */
/* ieee80211_ht_agg_queue_remove(local, sta, tid, 1); */
spin_unlock_bh(&local->mdev->queue_lock);

/* we just requeued the all the frames that were in the removed
* queue, and since we might miss a softirq we do netif_schedule.
* ieee80211_wake_queue is not used here as this queue is not
* necessarily stopped */
netif_schedule(local->mdev);
*state = HT_AGG_STATE_IDLE;
sta->ampdu_mlme.tid_tx[tid].addba_req_num = 0;
spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);

sta_info_put(sta);
}
EXPORT_SYMBOL(ieee80211_stop_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)) {
if (net_ratelimit())
printk(KERN_WARNING "%s: Not enough memory, "
"dropping start BA session", skb->dev->name);
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);

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)) {
if (net_ratelimit())
printk(KERN_WARNING "%s: Not enough memory, "
"dropping stop BA session", skb->dev->name);
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);

static void ieee80211_set_multicast_list(struct net_device *dev)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
Expand Down Expand Up @@ -713,6 +1036,7 @@ static void ieee80211_tasklet_handler(unsigned long data)
struct sk_buff *skb;
struct ieee80211_rx_status rx_status;
struct ieee80211_tx_status *tx_status;
struct ieee80211_ra_tid *ra_tid;

while ((skb = skb_dequeue(&local->skb_queue)) ||
(skb = skb_dequeue(&local->skb_queue_unreliable))) {
Expand All @@ -733,6 +1057,18 @@ static void ieee80211_tasklet_handler(unsigned long data)
skb, tx_status);
kfree(tx_status);
break;
case IEEE80211_DELBA_MSG:
ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
ieee80211_stop_tx_ba_cb(local_to_hw(local),
ra_tid->ra, ra_tid->tid);
dev_kfree_skb(skb);
break;
case IEEE80211_ADDBA_MSG:
ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
ieee80211_start_tx_ba_cb(local_to_hw(local),
ra_tid->ra, ra_tid->tid);
dev_kfree_skb(skb);
break ;
default: /* should never get here! */
printk(KERN_ERR "%s: Unknown message type (%d)\n",
wiphy_name(local->hw.wiphy), skb->pkt_type);
Expand Down
14 changes: 14 additions & 0 deletions net/mac80211/ieee80211_i.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -407,6 +407,8 @@ struct ieee80211_sub_if_data *vif_to_sdata(struct ieee80211_vif *p)
enum {
IEEE80211_RX_MSG = 1,
IEEE80211_TX_STATUS_MSG = 2,
IEEE80211_DELBA_MSG = 3,
IEEE80211_ADDBA_MSG = 4,
};

struct ieee80211_local {
Expand Down Expand Up @@ -627,6 +629,12 @@ struct ieee80211_local {
#endif
};

/* this struct represents 802.11n's RA/TID combination */
struct ieee80211_ra_tid {
u8 ra[ETH_ALEN];
u16 tid;
};

static inline struct ieee80211_local *hw_to_local(
struct ieee80211_hw *hw)
{
Expand Down Expand Up @@ -782,9 +790,15 @@ int ieee80211_ht_cap_ie_to_ht_info(struct ieee80211_ht_cap *ht_cap_ie,
int ieee80211_ht_addt_info_ie_to_ht_bss_info(
struct ieee80211_ht_addt_info *ht_add_info_ie,
struct ieee80211_ht_bss_info *bss_info);
void ieee80211_send_addba_request(struct net_device *dev, const u8 *da,
u16 tid, u8 dialog_token, u16 start_seq_num,
u16 agg_size, u16 timeout);
void ieee80211_send_delba(struct net_device *dev, const u8 *da, u16 tid,
u16 initiator, u16 reason_code);
void ieee80211_sta_stop_rx_ba_session(struct net_device *dev, u8 *da,
u16 tid, u16 initiator, u16 reason);
void sta_rx_agg_session_timer_expired(unsigned long data);
void sta_addba_resp_timer_expired(unsigned long data);
/* ieee80211_iface.c */
int ieee80211_if_add(struct net_device *dev, const char *name,
struct net_device **new_dev, int type);
Expand Down
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