mac80211: transmit fragment list to drivers

Drivers can usually handle fragmented packets
much easier when they get the entire list of
fragments at once. The only thing they need to
do is keep enough space on the queues for up
to ten fragments of a single MSDU.

This allows them to implement this with a new
operation tx_frags.

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

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 0756049ae76d69c2a8cb9e2342deb868cefeaf94..5b5c8a7e26d7756923fa285784acbf257f4e8938 100644 (file)
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1760,11 +1760,21 @@ enum ieee80211_frame_release_type {
  *     skb contains the buffer starting from the IEEE 802.11 header.
  *     The low-level driver should send the frame out based on
  *     configuration in the TX control data. This handler should,
- *     preferably, never fail and stop queues appropriately, more
- *     importantly, however, it must never fail for A-MPDU-queues.
- *     This function should return NETDEV_TX_OK except in very
- *     limited cases.
- *     Must be implemented and atomic.
+ *     preferably, never fail and stop queues appropriately.
+ *     This must be implemented if @tx_frags is not.
+ *     Must be atomic.
+ *
+ * @tx_frags: Called to transmit multiple fragments of a single MSDU.
+ *     This handler must consume all fragments, sending out some of
+ *     them only is useless and it can't ask for some of them to be
+ *     queued again. If the frame is not fragmented the queue has a
+ *     single SKB only. To avoid issues with the networking stack
+ *     when TX status is reported the frames should be removed from
+ *     the skb queue.
+ *     If this is used, the tx_info @vif and @sta pointers will be
+ *     invalid -- you must not use them in that case.
+ *     This must be implemented if @tx isn't.
+ *     Must be atomic.
  *
  * @start: Called before the first netdevice attached to the hardware
  *     is enabled. This should turn on the hardware and must turn on
@@ -2101,6 +2111,8 @@ enum ieee80211_frame_release_type {
  */
 struct ieee80211_ops {
        void (*tx)(struct ieee80211_hw *hw, struct sk_buff *skb);
+       void (*tx_frags)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
+                        struct ieee80211_sta *sta, struct sk_buff_head *skbs);
        int (*start)(struct ieee80211_hw *hw);
        void (*stop)(struct ieee80211_hw *hw);
 #ifdef CONFIG_PM

diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index b12ed52732c814b976bfc0084e680782faf5442d..49cc5e0e8a6af67a5c733c6cff07155f9e5b69fd 100644 (file)
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -15,6 +15,14 @@ static inline void drv_tx(struct ieee80211_local *local, struct sk_buff *skb)
        local->ops->tx(&local->hw, skb);
 }
 
+static inline void drv_tx_frags(struct ieee80211_local *local,
+                               struct ieee80211_vif *vif,
+                               struct ieee80211_sta *sta,
+                               struct sk_buff_head *skbs)
+{
+       local->ops->tx_frags(&local->hw, vif, sta, skbs);
+}
+
 static inline int drv_start(struct ieee80211_local *local)
 {
        int ret;

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index e323d4e6647bd702ab0a5f0a63e5d1dbfc4fed7d..3df4482bb1d964e1a9d5ddc88664fd6d9b111477 100644 (file)
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -609,7 +609,7 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 
        local->hw.priv = (char *)local + ALIGN(sizeof(*local), NETDEV_ALIGN);
 
-       BUG_ON(!ops->tx);
+       BUG_ON(!ops->tx && !ops->tx_frags);
        BUG_ON(!ops->start);
        BUG_ON(!ops->stop);
        BUG_ON(!ops->config);

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 0cc68d0796a244251083c30625c03ed68d361a1e..facc80d23b0c5ef73d0c3fcc76ddf7ed8d6460a7 100644 (file)
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1200,24 +1200,15 @@ ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
        return TX_CONTINUE;
 }
 
-/*
- * Returns false if the frame couldn't be transmitted but was queued instead.
- */
-static bool __ieee80211_tx(struct ieee80211_local *local,
-                          struct sk_buff_head *skbs, int led_len,
-                          struct sta_info *sta, bool txpending)
+static bool ieee80211_tx_frags(struct ieee80211_local *local,
+                              struct ieee80211_vif *vif,
+                              struct ieee80211_sta *sta,
+                              struct sk_buff_head *skbs,
+                              bool txpending)
 {
        struct sk_buff *skb, *tmp;
        struct ieee80211_tx_info *info;
-       struct ieee80211_sub_if_data *sdata;
        unsigned long flags;
-       __le16 fc;
-
-       if (WARN_ON(skb_queue_empty(skbs)))
-               return true;
-
-       skb = skb_peek(skbs);
-       fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
 
        skb_queue_walk_safe(skbs, skb, tmp) {
                int q = skb_get_queue_mapping(skb);
@@ -1242,37 +1233,72 @@ static bool __ieee80211_tx(struct ieee80211_local *local,
                spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 
                info = IEEE80211_SKB_CB(skb);
+               info->control.vif = vif;
+               info->control.sta = sta;
 
-               sdata = vif_to_sdata(info->control.vif);
+               __skb_unlink(skb, skbs);
+               drv_tx(local, skb);
+       }
 
-               switch (sdata->vif.type) {
-               case NL80211_IFTYPE_MONITOR:
-                       info->control.vif = NULL;
-                       break;
-               case NL80211_IFTYPE_AP_VLAN:
-                       info->control.vif = &container_of(sdata->bss,
-                               struct ieee80211_sub_if_data, u.ap)->vif;
-                       break;
-               default:
-                       /* keep */
-                       break;
-               }
+       return true;
+}
 
-               if (sta && sta->uploaded)
-                       info->control.sta = &sta->sta;
-               else
-                       info->control.sta = NULL;
+/*
+ * Returns false if the frame couldn't be transmitted but was queued instead.
+ */
+static bool __ieee80211_tx(struct ieee80211_local *local,
+                          struct sk_buff_head *skbs, int led_len,
+                          struct sta_info *sta, bool txpending)
+{
+       struct ieee80211_tx_info *info;
+       struct ieee80211_sub_if_data *sdata;
+       struct ieee80211_vif *vif;
+       struct ieee80211_sta *pubsta;
+       struct sk_buff *skb;
+       bool result = true;
+       __le16 fc;
 
-               __skb_unlink(skb, skbs);
-               drv_tx(local, skb);
+       if (WARN_ON(skb_queue_empty(skbs)))
+               return true;
+
+       skb = skb_peek(skbs);
+       fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
+       info = IEEE80211_SKB_CB(skb);
+       sdata = vif_to_sdata(info->control.vif);
+       if (sta && !sta->uploaded)
+               sta = NULL;
+
+       if (sta)
+               pubsta = &sta->sta;
+       else
+               pubsta = NULL;
+
+       switch (sdata->vif.type) {
+       case NL80211_IFTYPE_MONITOR:
+               sdata = NULL;
+               vif = NULL;
+               break;
+       case NL80211_IFTYPE_AP_VLAN:
+               sdata = container_of(sdata->bss,
+                                    struct ieee80211_sub_if_data, u.ap);
+               /* fall through */
+       default:
+               vif = &sdata->vif;
+               break;
        }
 
+       if (local->ops->tx_frags)
+               drv_tx_frags(local, vif, pubsta, skbs);
+       else
+               result = ieee80211_tx_frags(local, vif, pubsta, skbs,
+                                           txpending);
+
        ieee80211_tpt_led_trig_tx(local, fc, led_len);
        ieee80211_led_tx(local, 1);
 
        WARN_ON(!skb_queue_empty(skbs));
 
-       return true;
+       return result;
 }
 
 /*