mac80211: restructure __ieee80211_rx

This patch makes a separation between Rx frame pre-handling which stays in
__ieee80211_rx and Rx frame handlers, moving to __ieee80211_rx_handle_packet.
Although this separation has no affect in regular mode of operation, this kind
of mechanism will be used in A-MPDU frames reordering as it allows accumulation
of frames during pre-handling, dispatching them to later handling when necessary.

Signed-off-by: Ron Rindjunsky <ron.rindjunsky@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 50 insertions, 36 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 306e6fc25d8f..a58a94b21401 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -288,11 +288,11 @@ ieee80211_rx_h_parse_qos(struct ieee80211_txrx_data *rx)
         return TXRX_CONTINUE;
 }
 
-static ieee80211_txrx_result
-ieee80211_rx_h_load_stats(struct ieee80211_txrx_data *rx)
+
+u32 ieee80211_rx_load_stats(struct ieee80211_local *local,
+                              struct sk_buff *skb,
+                              struct ieee80211_rx_status *status)
 {
-        struct ieee80211_local *local = rx->local;
-        struct sk_buff *skb = rx->skb;
         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
         u32 load = 0, hdrtime;
         struct ieee80211_rate *rate;
@@ -306,7 +306,7 @@ ieee80211_rx_h_load_stats(struct ieee80211_txrx_data *rx)
 
         rate = &mode->rates[0];
         for (i = 0; i < mode->num_rates; i++) {
-                if (mode->rates[i].val == rx->u.rx.status->rate) {
+                if (mode->rates[i].val == status->rate) {
                         rate = &mode->rates[i];
                         break;
                 }
@@ -331,15 +331,13 @@ ieee80211_rx_h_load_stats(struct ieee80211_txrx_data *rx)
         /* Divide channel_use by 8 to avoid wrapping around the counter */
         load >>= CHAN_UTIL_SHIFT;
         local->channel_use_raw += load;
-        rx->u.rx.load = load;
 
-        return TXRX_CONTINUE;
+        return load;
 }
 
 ieee80211_rx_handler ieee80211_rx_pre_handlers[] =
 {
         ieee80211_rx_h_parse_qos,
-        ieee80211_rx_h_load_stats,
         NULL
 };
 
@@ -1613,11 +1611,11 @@ static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
 }
 
 /*
- * This is the receive path handler. It is called by a low level driver when an
- * 802.11 MPDU is received from the hardware.
+ * This is the actual Rx frames handler. as it blongs to Rx path it must
+ * be called with rcu_read_lock protection.
  */
-void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
-                    struct ieee80211_rx_status *status)
+void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw, struct sk_buff *skb,
+                            struct ieee80211_rx_status *status, u32 load)
 {
         struct ieee80211_local *local = hw_to_local(hw);
         struct ieee80211_sub_if_data *sdata;
@@ -1625,37 +1623,19 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
         struct ieee80211_hdr *hdr;
         struct ieee80211_txrx_data rx;
         u16 type;
-        int prepres;
+        int prepares;
         struct ieee80211_sub_if_data *prev = NULL;
         struct sk_buff *skb_new;
         u8 *bssid;
         int hdrlen;
 
-        /*
-         * key references and virtual interfaces are protected using RCU
-         * and this requires that we are in a read-side RCU section during
-         * receive processing
-         */
-        rcu_read_lock();
-
-        /*
-         * Frames with failed FCS/PLCP checksum are not returned,
-         * all other frames are returned without radiotap header
-         * if it was previously present.
-         * Also, frames with less than 16 bytes are dropped.
-         */
-        skb = ieee80211_rx_monitor(local, skb, status);
-        if (!skb) {
-                rcu_read_unlock();
-                return;
-        }
-
         hdr = (struct ieee80211_hdr *) skb->data;
         memset(&rx, 0, sizeof(rx));
         rx.skb = skb;
         rx.local = local;
 
         rx.u.rx.status = status;
+        rx.u.rx.load = load;
         rx.fc = le16_to_cpu(hdr->frame_control);
         type = rx.fc & IEEE80211_FCTL_FTYPE;
 
@@ -1714,11 +1694,11 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
                         continue;
 
                 rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
-                prepres = prepare_for_handlers(sdata, bssid, &rx, hdr);
+                prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
                 /* prepare_for_handlers can change sta */
                 sta = rx.sta;
 
-                if (!prepres)
+                if (!prepares)
                         continue;
 
                 /*
@@ -1765,11 +1745,45 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
                 dev_kfree_skb(skb);
 
  end:
-        rcu_read_unlock();
-
         if (sta)
                 sta_info_put(sta);
 }
+
+/*
+ * This is the receive path handler. It is called by a low level driver when an
+ * 802.11 MPDU is received from the hardware.
+ */
+void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
+                    struct ieee80211_rx_status *status)
+{
+        struct ieee80211_local *local = hw_to_local(hw);
+        u32 pkt_load;
+
+        /*
+         * key references and virtual interfaces are protected using RCU
+         * and this requires that we are in a read-side RCU section during
+         * receive processing
+         */
+        rcu_read_lock();
+
+        /*
+         * Frames with failed FCS/PLCP checksum are not returned,
+         * all other frames are returned without radiotap header
+         * if it was previously present.
+         * Also, frames with less than 16 bytes are dropped.
+         */
+        skb = ieee80211_rx_monitor(local, skb, status);
+        if (!skb) {
+                rcu_read_unlock();
+                return;
+        }
+
+        pkt_load = ieee80211_rx_load_stats(local, skb, status);
+
+        __ieee80211_rx_handle_packet(hw, skb, status, pkt_load);
+
+        rcu_read_unlock();
+}
 EXPORT_SYMBOL(__ieee80211_rx);
 
 /* This is a version of the rx handler that can be called from hard irq