From 07346f81e87d6e4cca7ae9adfa711d0c61c87b56 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Sat, 3 May 2008 01:02:02 +0200 Subject: mac80211: proper STA info locking As discussed earlier, we can unify locking in struct sta_info and use just a single spinlock protecting all members of the structure that need protection. Many don't, but one of the especially bad ones is the 'flags' member that can currently be clobbered when RX and TX is being processed on different CPUs at the same time. Because having four spinlocks for different, mostly exclusive parts of a single structure is overkill, this patch also kills the ampdu and mesh plink spinlocks and uses just a single one for everything. Because none of the spinlocks are nested, this is safe. It remains to be seen whether or not we should make the sta flags use atomic bit operations instead, for now though this is a safe thing and using atomic operations instead will be very simple using the new static inline functions this patch introduces for accessing sta->flags. Since spin_lock_bh() is used with this lock, there shouldn't be any contention even if aggregation is enabled at around the same time as both requires frame transmission/reception which is in a bh context. Signed-off-by: Johannes Berg Cc: Tomas Winkler Cc: Ron Rindjunsky Cc: Luis Carlos Cobo Signed-off-by: John W. Linville --- net/mac80211/rx.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'net/mac80211/rx.c') diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index e8b89c89e875..b399e09ec7aa 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -479,7 +479,7 @@ ieee80211_rx_h_check(struct ieee80211_rx_data *rx) ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL && (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) && rx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS && - (!rx->sta || !(rx->sta->flags & WLAN_STA_ASSOC)))) { + (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) { if ((!(rx->fc & IEEE80211_FCTL_FROMDS) && !(rx->fc & IEEE80211_FCTL_TODS) && (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) @@ -630,8 +630,7 @@ static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta) if (sdata->bss) atomic_inc(&sdata->bss->num_sta_ps); - sta->flags |= WLAN_STA_PS; - sta->flags &= ~WLAN_STA_PSPOLL; + set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL); #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n", dev->name, print_mac(mac, sta->addr), sta->aid); @@ -652,7 +651,7 @@ static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta) if (sdata->bss) atomic_dec(&sdata->bss->num_sta_ps); - sta->flags &= ~(WLAN_STA_PS | WLAN_STA_PSPOLL); + clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL); if (!skb_queue_empty(&sta->ps_tx_buf)) sta_info_clear_tim_bit(sta); @@ -727,9 +726,10 @@ ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx) if (!(rx->fc & IEEE80211_FCTL_MOREFRAGS)) { /* Change STA power saving mode only in the end of a frame * exchange sequence */ - if ((sta->flags & WLAN_STA_PS) && !(rx->fc & IEEE80211_FCTL_PM)) + if (test_sta_flags(sta, WLAN_STA_PS) && + !(rx->fc & IEEE80211_FCTL_PM)) rx->sent_ps_buffered += ap_sta_ps_end(dev, sta); - else if (!(sta->flags & WLAN_STA_PS) && + else if (!test_sta_flags(sta, WLAN_STA_PS) && (rx->fc & IEEE80211_FCTL_PM)) ap_sta_ps_start(dev, sta); } @@ -983,7 +983,7 @@ ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx) * Tell TX path to send one frame even though the STA may * still remain is PS mode after this frame exchange. */ - rx->sta->flags |= WLAN_STA_PSPOLL; + set_sta_flags(rx->sta, WLAN_STA_PSPOLL); #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n", @@ -1046,7 +1046,8 @@ ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx) static int ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx) { - if (unlikely(!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED))) { + if (unlikely(!rx->sta || + !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED))) { #ifdef CONFIG_MAC80211_DEBUG if (net_ratelimit()) printk(KERN_DEBUG "%s: dropped frame " -- cgit v1.2.3