mac80211: push rx status into skb->cb

Within mac80211, we often need to copy the rx status into
skb->cb. This is wasteful, as drivers could be building it
in there to start with. This patch changes the API so that
drivers are expected to pass the RX status in skb->cb, now
accessible as IEEE80211_SKB_RXCB(skb). It also updates all
drivers to pass the rx status in there, but only by making
them memcpy() it into place before the call to the receive
function (ieee80211_rx(_irqsafe)). Each driver can now be
optimised on its own schedule.

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

3 files changed, 15 insertions, 7 deletions

diff --git a/drivers/net/wireless/ath/ar9170/main.c b/drivers/net/wireless/ath/ar9170/main.c
index 9d38cf60a0db..51753ed1b8ba 100644
--- a/drivers/net/wireless/ath/ar9170/main.c
+++ b/drivers/net/wireless/ath/ar9170/main.c
@@ -917,8 +917,10 @@ static void ar9170_handle_mpdu(struct ar9170 *ar, u8 *buf, int len)
                 ar9170_rx_phy_status(ar, phy, &status);
 
         skb = ar9170_rx_copy_data(buf, mpdu_len);
-        if (likely(skb))
-                ieee80211_rx_irqsafe(ar->hw, skb, &status);
+        if (likely(skb)) {
+                memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
+                ieee80211_rx_irqsafe(ar->hw, skb);
+        }
 }
 
 void ar9170_rx(struct ar9170 *ar, struct sk_buff *skb)
diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c
index f26a68960622..c6e70919435c 100644
--- a/drivers/net/wireless/ath/ath5k/base.c
+++ b/drivers/net/wireless/ath/ath5k/base.c
@@ -1905,7 +1905,8 @@ accept:
                 if (sc->opmode == NL80211_IFTYPE_ADHOC)
                         ath5k_check_ibss_tsf(sc, skb, &rxs);
 
-                __ieee80211_rx(sc->hw, skb, &rxs);
+                memcpy(IEEE80211_SKB_RXCB(skb), &rxs, sizeof(rxs));
+                ieee80211_rx(sc->hw, skb);
 
                 bf->skb = next_skb;
                 bf->skbaddr = next_skb_addr;
diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index cece1c4c6bda..c00b9051bb53 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -619,13 +619,18 @@ static void ath_rx_send_to_mac80211(struct ath_softc *sc, struct sk_buff *skb,
                         if (aphy == NULL)
                                 continue;
                         nskb = skb_copy(skb, GFP_ATOMIC);
-                        if (nskb)
-                                __ieee80211_rx(aphy->hw, nskb, rx_status);
+                        if (nskb) {
+                                memcpy(IEEE80211_SKB_RXCB(nskb), rx_status,
+                                        sizeof(*rx_status));
+                                ieee80211_rx(aphy->hw, nskb);
+                        }
                 }
-                __ieee80211_rx(sc->hw, skb, rx_status);
+                memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status));
+                ieee80211_rx(sc->hw, skb);
         } else {
                 /* Deliver unicast frames based on receiver address */
-                __ieee80211_rx(ath_get_virt_hw(sc, hdr), skb, rx_status);
+                memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status));
+                ieee80211_rx(ath_get_virt_hw(sc, hdr), skb);
         }
 }