[RFC,20/21] mac80211: change TX aggregation locking

Message ID	20100607110202.793250520@sipsolutions.net (mailing list archive)
State	Not Applicable, archived
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o57B3WTR021907 for <patchwork-linux-wireless@patchwork.kernel.org>; Mon, 7 Jun 2010 11:03:32 GMT Message-Id: <20100607110202.793250520@sipsolutions.net> User-Agent: quilt/0.48-1 Date: Mon, 07 Jun 2010 13:01:53 +0200 From: Johannes Berg <johannes@sipsolutions.net> To: linux-wireless@vger.kernel.org Subject: [RFC 20/21] mac80211: change TX aggregation locking References: <20100607110133.472649120@sipsolutions.net> Content-Disposition: inline; filename=023-mac80211-sleeping-ampdu-tx.patch Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk

--- wireless-testing.orig/net/mac80211/agg-tx.c 2010-06-07 12:22:12.000000000 +0200 +++ wireless-testing/net/mac80211/agg-tx.c 2010-06-07 12:32:28.000000000 +0200 @@ -140,18 +140,25 @@ int ___ieee80211_stop_tx_ba_session(stru struct tid_ampdu_tx *tid_tx = sta->ampdu_mlme.tid_tx[tid]; int ret; - lockdep_assert_held(&sta->lock); + lockdep_assert_held(&sta->ampdu_mlme.mtx); - if (WARN_ON(!tid_tx)) + spin_lock_bh(&sta->lock); + + if (!tid_tx) { + spin_unlock_bh(&sta->lock); return -ENOENT; + } if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) { /* not even started yet! */ rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL); + spin_unlock_bh(&sta->lock); call_rcu(&tid_tx->rcu_head, kfree_tid_tx); return 0; } + spin_unlock_bh(&sta->lock); + #ifdef CONFIG_MAC80211_HT_DEBUG printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n", sta->sta.addr, tid); @@ -281,10 +288,11 @@ void ieee80211_tx_ba_session_handle_star clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); /* - * This might be off by one due to a race that we can't - * really prevent here without synchronize_net() which - * can't be called now. + * make sure no packets are being processed to get + * valid starting sequence number */ + synchronize_net(); + start_seq_num = sta->tid_seq[tid] >> 4; ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START, @@ -294,7 +302,10 @@ void ieee80211_tx_ba_session_handle_star printk(KERN_DEBUG "BA request denied - HW unavailable for" " tid %d\n", tid); #endif + spin_lock_bh(&sta->lock); rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL); + spin_unlock_bh(&sta->lock); + ieee80211_wake_queue_agg(local, tid); call_rcu(&tid_tx->rcu_head, kfree_tid_tx); return; @@ -445,16 +456,25 @@ ieee80211_agg_splice_finish(struct ieee8 ieee80211_wake_queue_agg(local, tid); } -/* caller must hold sta->lock */ static void ieee80211_agg_tx_operational(struct ieee80211_local *local, struct sta_info *sta, u16 tid) { - lockdep_assert_held(&sta->lock); + lockdep_assert_held(&sta->ampdu_mlme.mtx); #ifdef CONFIG_MAC80211_HT_DEBUG printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid); #endif + drv_ampdu_action(local, sta->sdata, + IEEE80211_AMPDU_TX_OPERATIONAL, + &sta->sta, tid, NULL); + + /* + * synchronize with TX path, while splicing the TX path + * should block so it won't put more packets onto pending. + */ + spin_lock_bh(&sta->lock); + ieee80211_agg_splice_packets(local, sta->ampdu_mlme.tid_tx[tid], tid); /* * Now mark as operational. This will be visible @@ -464,9 +484,7 @@ static void ieee80211_agg_tx_operational set_bit(HT_AGG_STATE_OPERATIONAL, &sta->ampdu_mlme.tid_tx[tid]->state); ieee80211_agg_splice_finish(local, tid); - drv_ampdu_action(local, sta->sdata, - IEEE80211_AMPDU_TX_OPERATIONAL, - &sta->sta, tid, NULL); + spin_unlock_bh(&sta->lock); } void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid) @@ -486,37 +504,35 @@ void ieee80211_start_tx_ba_cb(struct iee return; } - rcu_read_lock(); + mutex_lock(&local->sta_mtx); sta = sta_info_get(sdata, ra); if (!sta) { - rcu_read_unlock(); + mutex_unlock(&local->sta_mtx); #ifdef CONFIG_MAC80211_HT_DEBUG printk(KERN_DEBUG "Could not find station: %pM\n", ra); #endif return; } - spin_lock_bh(&sta->lock); + mutex_lock(&sta->ampdu_mlme.mtx); tid_tx = sta->ampdu_mlme.tid_tx[tid]; if (WARN_ON(!tid_tx)) { #ifdef CONFIG_MAC80211_HT_DEBUG printk(KERN_DEBUG "addBA was not requested!\n"); #endif - spin_unlock_bh(&sta->lock); - rcu_read_unlock(); - return; + goto unlock; } if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) - goto out; + goto unlock; if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) ieee80211_agg_tx_operational(local, sta, tid); - out: - spin_unlock_bh(&sta->lock); - rcu_read_unlock(); + unlock: + mutex_unlock(&sta->ampdu_mlme.mtx); + mutex_unlock(&local->sta_mtx); } void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, @@ -548,21 +564,14 @@ EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_i int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, enum ieee80211_back_parties initiator) { - struct tid_ampdu_tx *tid_tx; int ret; - spin_lock_bh(&sta->lock); - tid_tx = sta->ampdu_mlme.tid_tx[tid]; - - if (!tid_tx) { - ret = -ENOENT; - goto unlock; - } + mutex_lock(&sta->ampdu_mlme.mtx); ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator); - unlock: - spin_unlock_bh(&sta->lock); + mutex_unlock(&sta->ampdu_mlme.mtx); + return ret; } @@ -627,16 +636,17 @@ void ieee80211_stop_tx_ba_cb(struct ieee ra, tid); #endif /* CONFIG_MAC80211_HT_DEBUG */ - rcu_read_lock(); + mutex_lock(&local->sta_mtx); + sta = sta_info_get(sdata, ra); if (!sta) { #ifdef CONFIG_MAC80211_HT_DEBUG printk(KERN_DEBUG "Could not find station: %pM\n", ra); #endif - rcu_read_unlock(); - return; + goto unlock; } + mutex_lock(&sta->ampdu_mlme.mtx); spin_lock_bh(&sta->lock); tid_tx = sta->ampdu_mlme.tid_tx[tid]; @@ -644,9 +654,7 @@ void ieee80211_stop_tx_ba_cb(struct ieee #ifdef CONFIG_MAC80211_HT_DEBUG printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n"); #endif - spin_unlock_bh(&sta->lock); - rcu_read_unlock(); - return; + goto unlock_sta; } if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR) @@ -672,8 +680,11 @@ void ieee80211_stop_tx_ba_cb(struct ieee call_rcu(&tid_tx->rcu_head, kfree_tid_tx); + unlock_sta: spin_unlock_bh(&sta->lock); - rcu_read_unlock(); + mutex_unlock(&sta->ampdu_mlme.mtx); + unlock: + mutex_unlock(&local->sta_mtx); } void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, @@ -714,10 +725,9 @@ void ieee80211_process_addba_resp(struct capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab); tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; - spin_lock_bh(&sta->lock); + mutex_lock(&sta->ampdu_mlme.mtx); tid_tx = sta->ampdu_mlme.tid_tx[tid]; - if (!tid_tx) goto out; @@ -751,5 +761,5 @@ void ieee80211_process_addba_resp(struct } out: - spin_unlock_bh(&sta->lock); + mutex_unlock(&sta->ampdu_mlme.mtx); } --- wireless-testing.orig/net/mac80211/ht.c 2010-06-07 12:22:08.000000000 +0200 +++ wireless-testing/net/mac80211/ht.c 2010-06-07 12:22:13.000000000 +0200 @@ -136,11 +136,7 @@ void ieee80211_ba_session_work(struct wo ___ieee80211_stop_rx_ba_session( sta, tid, WLAN_BACK_RECIPIENT, WLAN_REASON_QSTA_TIMEOUT); - } - mutex_unlock(&sta->ampdu_mlme.mtx); - spin_lock_bh(&sta->lock); - for (tid = 0; tid < STA_TID_NUM; tid++) { tid_tx = sta->ampdu_mlme.tid_tx[tid]; if (!tid_tx) continue; @@ -152,7 +148,7 @@ void ieee80211_ba_session_work(struct wo ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR); } - spin_unlock_bh(&sta->lock); + mutex_unlock(&sta->ampdu_mlme.mtx); } void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata, --- wireless-testing.orig/net/mac80211/driver-ops.h 2010-06-07 12:22:20.000000000 +0200 +++ wireless-testing/net/mac80211/driver-ops.h 2010-06-07 12:22:31.000000000 +0200 @@ -349,6 +349,9 @@ static inline int drv_ampdu_action(struc u16 *ssn) { int ret = -EOPNOTSUPP; + + might_sleep(); + local_bh_disable(); if (local->ops->ampdu_action) ret = local->ops->ampdu_action(&local->hw, &sdata->vif, action,

[RFC,20/21] mac80211: change TX aggregation locking

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