mac80211: A-MPDU Tx add session's and low level driver's API

This patch adds the API for 3 stages in A-MPDU Tx session flow:
- request mac80211 to start/stop A-MPDU Tx session for specific TID. such a
  request should be issued by a load aware element, either mac80211 itself
  or external element.
- requests by mac80211 to low-level driver to start/stop Tx aggregation.
  notice that low level driver responds now with Starting Sequence Number.
- async feedback by low-level to mac80211 to inform that HW is ready for
  next A-MPDU Tx state.
Changes in API to Rx A-MPDU were also made, reflected in iwlwifi changes as
well.

Signed-off-by: Ron Rindjunsky <ron.rindjunsky@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-4965.c

@@ -4732,7 +4732,7 @@ static void iwl4965_sta_modify_del_ba_tid(struct iwl4965_priv *priv,
 
 int iwl4965_mac_ampdu_action(struct ieee80211_hw *hw,
 			     enum ieee80211_ampdu_mlme_action action,
-			     const u8 *addr, u16 tid, u16 ssn)
+			     const u8 *addr, u16 tid, u16 *ssn)
 {
 	struct iwl4965_priv *priv = hw->priv;
 	int sta_id;
@@ -4744,7 +4744,7 @@ int iwl4965_mac_ampdu_action(struct ieee80211_hw *hw,
 	switch (action) {
 	case IEEE80211_AMPDU_RX_START:
 		IWL_DEBUG_HT("start Rx\n");
-		iwl4965_sta_modify_add_ba_tid(priv, sta_id, tid, ssn);
+		iwl4965_sta_modify_add_ba_tid(priv, sta_id, tid, *ssn);
 		break;
 	case IEEE80211_AMPDU_RX_STOP:
 		IWL_DEBUG_HT("stop Rx\n");

drivers/net/wireless/iwlwifi/iwl-4965.h

@@ -777,7 +777,7 @@ extern void iwl4965_set_ht_add_station(struct iwl4965_priv *priv, u8 index,
 				struct ieee80211_ht_info *sta_ht_inf);
 extern int iwl4965_mac_ampdu_action(struct ieee80211_hw *hw,
 				    enum ieee80211_ampdu_mlme_action action,
-				    const u8 *addr, u16 tid, u16 ssn);
+				    const u8 *addr, u16 tid, u16 *ssn);
 #ifdef CONFIG_IWL4965_HT_AGG
 extern int iwl4965_mac_ht_tx_agg_start(struct ieee80211_hw *hw, u8 *da,
 				   u16 tid, u16 *start_seq_num);