mac80211: consolidate TIM handling code

This consolidates all TIM handling code to avoid re-introducing
errors with the bitmap/set_tim order and to reduce code. While
reading the code I noticed a possible problem so I also added
a comment about that.

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

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 1b4a449..b07b3cb 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -207,7 +207,7 @@ struct ieee80211_if_ap {
 
        /* yes, this looks ugly, but guarantees that we can later use
         * bitmap_empty :)
-        * NB: don't ever use set_bit, use bss_tim_set/bss_tim_clear! */
+        * NB: don't touch this bitmap, use sta_info_{set,clear}_tim_bit */
        u8 tim[sizeof(unsigned long) * BITS_TO_LONGS(IEEE80211_MAX_AID + 1)];
        atomic_t num_sta_ps; /* number of stations in PS mode */
        struct sk_buff_head ps_bc_buf;
@@ -640,40 +640,6 @@ struct sta_attribute {
        ssize_t (*store)(struct sta_info *, const char *buf, size_t count);
 };
 
-static inline void __bss_tim_set(struct ieee80211_if_ap *bss, u16 aid)
-{
-       /*
-        * This format has been mandated by the IEEE specifications,
-        * so this line may not be changed to use the __set_bit() format.
-        */
-       bss->tim[aid / 8] |= (1 << (aid % 8));
-}
-
-static inline void bss_tim_set(struct ieee80211_local *local,
-                              struct ieee80211_if_ap *bss, u16 aid)
-{
-       read_lock_bh(&local->sta_lock);
-       __bss_tim_set(bss, aid);
-       read_unlock_bh(&local->sta_lock);
-}
-
-static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, u16 aid)
-{
-       /*
-        * This format has been mandated by the IEEE specifications,
-        * so this line may not be changed to use the __clear_bit() format.
-        */
-       bss->tim[aid / 8] &= ~(1 << (aid % 8));
-}
-
-static inline void bss_tim_clear(struct ieee80211_local *local,
-                                struct ieee80211_if_ap *bss, u16 aid)
-{
-       read_lock_bh(&local->sta_lock);
-       __bss_tim_clear(bss, aid);
-       read_unlock_bh(&local->sta_lock);
-}
-
 static inline int ieee80211_bssid_match(const u8 *raddr, const u8 *addr)
 {
        return compare_ether_addr(raddr, addr) == 0 ||

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 0e8a371..48574f6 100644 (file)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -596,19 +596,20 @@ static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
        DECLARE_MAC_BUF(mac);
 
        sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
+
        if (sdata->bss)
                atomic_dec(&sdata->bss->num_sta_ps);
+
        sta->flags &= ~(WLAN_STA_PS | WLAN_STA_PSPOLL);
-       if (!skb_queue_empty(&sta->ps_tx_buf)) {
-               if (sdata->bss)
-                       bss_tim_clear(local, sdata->bss, sta->aid);
-               if (local->ops->set_tim)
-                       local->ops->set_tim(local_to_hw(local), sta->aid, 0);
-       }
+
+       if (!skb_queue_empty(&sta->ps_tx_buf))
+               sta_info_clear_tim_bit(sta);
+
 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
        printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
               dev->name, print_mac(mac, sta->addr), sta->aid);
 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
+
        /* Send all buffered frames to the station */
        while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
                pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
@@ -945,20 +946,20 @@ ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx)
 
                dev_queue_xmit(skb);
 
-               if (no_pending_pkts) {
-                       if (rx->sdata->bss)
-                               bss_tim_clear(rx->local, rx->sdata->bss, rx->sta->aid);
-                       if (rx->local->ops->set_tim)
-                               rx->local->ops->set_tim(local_to_hw(rx->local),
-                                                      rx->sta->aid, 0);
-               }
+               if (no_pending_pkts)
+                       sta_info_clear_tim_bit(rx->sta);
 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
        } else if (!rx->u.rx.sent_ps_buffered) {
+               /*
+                * FIXME: This can be the result of a race condition between
+                *        us expiring a frame and the station polling for it.
+                *        Should we send it a null-func frame indicating we
+                *        have nothing buffered for it?
+                */
                printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
                       "though there is no buffered frames for it\n",
                       rx->dev->name, print_mac(mac, rx->sta->addr));
 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
-
        }
 
        /* Free PS Poll skb here instead of returning RX_DROP that would

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index a843bb7..b31a627 100644 (file)
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -191,6 +191,64 @@ struct sta_info * sta_info_add(struct ieee80211_local *local,
        return sta;
 }
 
+static inline void __bss_tim_set(struct ieee80211_if_ap *bss, u16 aid)
+{
+       /*
+        * This format has been mandated by the IEEE specifications,
+        * so this line may not be changed to use the __set_bit() format.
+        */
+       bss->tim[aid / 8] |= (1 << (aid % 8));
+}
+
+static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, u16 aid)
+{
+       /*
+        * This format has been mandated by the IEEE specifications,
+        * so this line may not be changed to use the __clear_bit() format.
+        */
+       bss->tim[aid / 8] &= ~(1 << (aid % 8));
+}
+
+static void __sta_info_set_tim_bit(struct ieee80211_if_ap *bss,
+                                  struct sta_info *sta)
+{
+       if (bss)
+               __bss_tim_set(bss, sta->aid);
+       if (sta->local->ops->set_tim)
+               sta->local->ops->set_tim(local_to_hw(sta->local), sta->aid, 1);
+}
+
+void sta_info_set_tim_bit(struct sta_info *sta)
+{
+       struct ieee80211_sub_if_data *sdata;
+
+       sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
+
+       read_lock_bh(&sta->local->sta_lock);
+       __sta_info_set_tim_bit(sdata->bss, sta);
+       read_unlock_bh(&sta->local->sta_lock);
+}
+
+static void __sta_info_clear_tim_bit(struct ieee80211_if_ap *bss,
+                                    struct sta_info *sta)
+{
+       if (bss)
+               __bss_tim_clear(bss, sta->aid);
+       if (sta->local->ops->set_tim)
+               sta->local->ops->set_tim(local_to_hw(sta->local), sta->aid, 0);
+}
+
+void sta_info_clear_tim_bit(struct sta_info *sta)
+{
+       struct ieee80211_sub_if_data *sdata;
+
+       sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
+
+       read_lock_bh(&sta->local->sta_lock);
+       __sta_info_clear_tim_bit(sdata->bss, sta);
+       read_unlock_bh(&sta->local->sta_lock);
+}
+
 /* Caller must hold local->sta_lock */
 void sta_info_remove(struct sta_info *sta)
 {
@@ -207,10 +265,9 @@ void sta_info_remove(struct sta_info *sta)
                sta->flags &= ~WLAN_STA_PS;
                if (sdata->bss)
                        atomic_dec(&sdata->bss->num_sta_ps);
+               __sta_info_clear_tim_bit(sdata->bss, sta);
        }
        local->num_sta--;
-       sta_info_remove_aid_ptr(sta);
-
 }
 
 void sta_info_free(struct sta_info *sta)
@@ -310,13 +367,8 @@ static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
                       "%s)\n", print_mac(mac, sta->addr));
                dev_kfree_skb(skb);
 
-               if (skb_queue_empty(&sta->ps_tx_buf)) {
-                       if (sdata->bss)
-                               bss_tim_set(sta->local, sdata->bss, sta->aid);
-                       if (sta->local->ops->set_tim)
-                               sta->local->ops->set_tim(local_to_hw(sta->local),
-                                                        sta->aid, 0);
-               }
+               if (skb_queue_empty(&sta->ps_tx_buf))
+                       sta_info_clear_tim_bit(sta);
        }
 }
 
@@ -395,23 +447,6 @@ void sta_info_stop(struct ieee80211_local *local)
        sta_info_flush(local, NULL);
 }
 
-void sta_info_remove_aid_ptr(struct sta_info *sta)
-{
-       struct ieee80211_sub_if_data *sdata;
-
-       if (sta->aid <= 0)
-               return;
-
-       sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
-
-       if (sdata->bss)
-               __bss_tim_clear(sdata->bss, sta->aid);
-       if (sdata->local->ops->set_tim)
-               sdata->local->ops->set_tim(local_to_hw(sdata->local),
-                                         sta->aid, 0);
-}
-
-
 /**
  * sta_info_flush - flush matching STA entries from the STA table
  * @local: local interface data

diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index f3d9f87..4099ece 100644 (file)
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -244,7 +244,9 @@ void sta_info_free(struct sta_info *sta);
 void sta_info_init(struct ieee80211_local *local);
 int sta_info_start(struct ieee80211_local *local);
 void sta_info_stop(struct ieee80211_local *local);
-void sta_info_remove_aid_ptr(struct sta_info *sta);
 void sta_info_flush(struct ieee80211_local *local, struct net_device *dev);
 
+void sta_info_set_tim_bit(struct sta_info *sta);
+void sta_info_clear_tim_bit(struct sta_info *sta);
+
 #endif /* STA_INFO_H */

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index db6a871..69fdb76 100644 (file)
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -416,14 +416,11 @@ ieee80211_tx_h_unicast_ps_buf(struct ieee80211_txrx_data *tx)
                        dev_kfree_skb(old);
                } else
                        tx->local->total_ps_buffered++;
+
                /* Queue frame to be sent after STA sends an PS Poll frame */
-               if (skb_queue_empty(&sta->ps_tx_buf)) {
-                       if (tx->sdata->bss)
-                               bss_tim_set(tx->local, tx->sdata->bss, sta->aid);
-                       if (tx->local->ops->set_tim)
-                               tx->local->ops->set_tim(local_to_hw(tx->local),
-                                                      sta->aid, 1);
-               }
+               if (skb_queue_empty(&sta->ps_tx_buf))
+                       sta_info_set_tim_bit(sta);
+
                pkt_data = (struct ieee80211_tx_packet_data *)tx->skb->cb;
                pkt_data->jiffies = jiffies;
                skb_queue_tail(&sta->ps_tx_buf, tx->skb);