mac80211: unify TIM bit handling

Currently, the TIM bit for a given station is set
and cleared all over the place. Since the logic to
set/clear it will become much more complex when we
add uAPSD support, as a first step let's collect
the entire logic in one place. This requires a few
small adjustments to other places.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 42 insertions, 57 deletions

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 016742d4c48e..863d59fe6886 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -641,54 +641,42 @@ static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, u16 aid)
         bss->tim[aid / 8] &= ~(1 << (aid % 8));
 }
 
-static void __sta_info_set_tim_bit(struct ieee80211_if_ap *bss,
-                                   struct sta_info *sta)
-{
-        BUG_ON(!bss);
-
-        __bss_tim_set(bss, sta->sta.aid);
-
-        if (sta->local->ops->set_tim) {
-                sta->local->tim_in_locked_section = true;
-                drv_set_tim(sta->local, &sta->sta, true);
-                sta->local->tim_in_locked_section = false;
-        }
-}
-
-void sta_info_set_tim_bit(struct sta_info *sta)
+void sta_info_recalc_tim(struct sta_info *sta)
 {
+        struct ieee80211_local *local = sta->local;
+        struct ieee80211_if_ap *bss = sta->sdata->bss;
         unsigned long flags;
+        bool have_data = false;
 
-        BUG_ON(!sta->sdata->bss);
+        if (WARN_ON_ONCE(!sta->sdata->bss))
+                return;
 
-        spin_lock_irqsave(&sta->local->sta_lock, flags);
-        __sta_info_set_tim_bit(sta->sdata->bss, sta);
-        spin_unlock_irqrestore(&sta->local->sta_lock, flags);
-}
+        /* No need to do anything if the driver does all */
+        if (local->hw.flags & IEEE80211_HW_AP_LINK_PS)
+                return;
 
-static void __sta_info_clear_tim_bit(struct ieee80211_if_ap *bss,
-                                     struct sta_info *sta)
-{
-        BUG_ON(!bss);
+        if (sta->dead)
+                goto done;
 
-        __bss_tim_clear(bss, sta->sta.aid);
+        have_data = test_sta_flags(sta, WLAN_STA_PS_DRIVER_BUF) ||
+                    !skb_queue_empty(&sta->tx_filtered) ||
+                    !skb_queue_empty(&sta->ps_tx_buf);
 
-        if (sta->local->ops->set_tim) {
-                sta->local->tim_in_locked_section = true;
-                drv_set_tim(sta->local, &sta->sta, false);
-                sta->local->tim_in_locked_section = false;
-        }
-}
+ done:
+        spin_lock_irqsave(&local->sta_lock, flags);
 
-void sta_info_clear_tim_bit(struct sta_info *sta)
-{
-        unsigned long flags;
+        if (have_data)
+                __bss_tim_set(bss, sta->sta.aid);
+        else
+                __bss_tim_clear(bss, sta->sta.aid);
 
-        BUG_ON(!sta->sdata->bss);
+        if (local->ops->set_tim) {
+                local->tim_in_locked_section = true;
+                drv_set_tim(local, &sta->sta, have_data);
+                local->tim_in_locked_section = false;
+        }
 
-        spin_lock_irqsave(&sta->local->sta_lock, flags);
-        __sta_info_clear_tim_bit(sta->sdata->bss, sta);
-        spin_unlock_irqrestore(&sta->local->sta_lock, flags);
+        spin_unlock_irqrestore(&local->sta_lock, flags);
 }
 
 static bool sta_info_buffer_expired(struct sta_info *sta, struct sk_buff *skb)
@@ -717,6 +705,10 @@ static bool sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
         unsigned long flags;
         struct sk_buff *skb;
 
+        /* This is only necessary for stations on BSS interfaces */
+        if (!sta->sdata->bss)
+                return false;
+
         for (;;) {
                 spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
                 skb = skb_peek(&sta->ps_tx_buf);
@@ -736,9 +728,9 @@ static bool sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
 #endif
                 dev_kfree_skb(skb);
 
-                if (skb_queue_empty(&sta->ps_tx_buf) &&
-                    !test_sta_flags(sta, WLAN_STA_PS_DRIVER_BUF))
-                        sta_info_clear_tim_bit(sta);
+                /* if the queue is now empty recalc TIM bit */
+                if (skb_queue_empty(&sta->ps_tx_buf))
+                        sta_info_recalc_tim(sta);
         }
 
         return !skb_queue_empty(&sta->ps_tx_buf);
@@ -748,7 +740,6 @@ static int __must_check __sta_info_destroy(struct sta_info *sta)
 {
         struct ieee80211_local *local;
         struct ieee80211_sub_if_data *sdata;
-        struct sk_buff *skb;
         unsigned long flags;
         int ret, i;
 
@@ -792,7 +783,7 @@ static int __must_check __sta_info_destroy(struct sta_info *sta)
                 BUG_ON(!sdata->bss);
 
                 atomic_dec(&sdata->bss->num_sta_ps);
-                sta_info_clear_tim_bit(sta);
+                sta_info_recalc_tim(sta);
         }
 
         local->num_sta--;
@@ -818,6 +809,10 @@ static int __must_check __sta_info_destroy(struct sta_info *sta)
          */
         synchronize_rcu();
 
+        local->total_ps_buffered -= skb_queue_len(&sta->ps_tx_buf);
+        __skb_queue_purge(&sta->ps_tx_buf);
+        __skb_queue_purge(&sta->tx_filtered);
+
 #ifdef CONFIG_MAC80211_MESH
         if (ieee80211_vif_is_mesh(&sdata->vif))
                 mesh_accept_plinks_update(sdata);
@@ -840,14 +835,6 @@ static int __must_check __sta_info_destroy(struct sta_info *sta)
         }
 #endif
 
-        while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
-                local->total_ps_buffered--;
-                dev_kfree_skb_any(skb);
-        }
-
-        while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL)
-                dev_kfree_skb_any(skb);
-
         __sta_info_free(local, sta);
 
         return 0;
@@ -1027,9 +1014,6 @@ void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta)
         if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
                 drv_sta_notify(local, sdata, STA_NOTIFY_AWAKE, &sta->sta);
 
-        if (!skb_queue_empty(&sta->ps_tx_buf))
-                sta_info_clear_tim_bit(sta);
-
         /* Send all buffered frames to the station */
         sent = ieee80211_add_pending_skbs(local, &sta->tx_filtered);
         buffered = ieee80211_add_pending_skbs_fn(local, &sta->ps_tx_buf,
@@ -1037,6 +1021,8 @@ void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta)
         sent += buffered;
         local->total_ps_buffered -= buffered;
 
+        sta_info_recalc_tim(sta);
+
 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
         printk(KERN_DEBUG "%s: STA %pM aid %d sending %d filtered/%d PS frames "
                "since STA not sleeping anymore\n", sdata->name,
@@ -1086,8 +1072,7 @@ void ieee80211_sta_ps_deliver_poll_response(struct sta_info *sta)
 
                 ieee80211_add_pending_skb(local, skb);
 
-                if (no_pending_pkts)
-                        sta_info_clear_tim_bit(sta);
+                sta_info_recalc_tim(sta);
 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
         } else {
                 /*
@@ -1126,6 +1111,6 @@ void ieee80211_sta_set_buffered(struct ieee80211_sta *pubsta,
                 return;
 
         set_sta_flags(sta, WLAN_STA_PS_DRIVER_BUF);
-        sta_info_set_tim_bit(sta);
+        sta_info_recalc_tim(sta);
 }
 EXPORT_SYMBOL(ieee80211_sta_set_buffered);