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>

drivers/net/wireless/adm8211.c

@@ -452,7 +452,8 @@ static void adm8211_interrupt_rci(struct ieee80211_hw *dev)
 			rx_status.freq = adm8211_channels[priv->channel - 1].center_freq;
 			rx_status.band = IEEE80211_BAND_2GHZ;
 
-			ieee80211_rx_irqsafe(dev, skb, &rx_status);
+			memcpy(IEEE80211_SKB_RXCB(skb), &rx_status, sizeof(rx_status));
+			ieee80211_rx_irqsafe(dev, skb);
 		}
 
 		entry = (++priv->cur_rx) % priv->rx_ring_size;

drivers/net/wireless/at76c50x-usb.c

@@ -1568,7 +1568,8 @@ static void at76_rx_tasklet(unsigned long param)
 
 	at76_dbg(DBG_MAC80211, "calling ieee80211_rx_irqsafe(): %d/%d",
 		 priv->rx_skb->len, priv->rx_skb->data_len);
-	ieee80211_rx_irqsafe(priv->hw, priv->rx_skb, &rx_status);
+	memcpy(IEEE80211_SKB_RXCB(priv->rx_skb), &rx_status, sizeof(rx_status));
+	ieee80211_rx_irqsafe(priv->hw, priv->rx_skb);
 
 	/* Use a new skb for the next receive */
 	priv->rx_skb = NULL;

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)

drivers/net/wireless/ath/ath5k/base.c

@@ -1905,7 +1905,8 @@ ath5k_tasklet_rx(unsigned long data)
 		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;

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);
 	}
 }
 

drivers/net/wireless/b43/xmit.c

@@ -670,7 +670,8 @@ void b43_rx(struct b43_wldev *dev, struct sk_buff *skb, const void *_rxhdr)
 		goto drop;
 	}
 
-	ieee80211_rx_irqsafe(dev->wl->hw, skb, &status);
+	memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
+	ieee80211_rx_irqsafe(dev->wl->hw, skb);
 
 	return;
 drop:

drivers/net/wireless/b43legacy/xmit.c

@@ -591,7 +591,8 @@ void b43legacy_rx(struct b43legacy_wldev *dev,
 	}
 
 	dev->stats.last_rx = jiffies;
-	ieee80211_rx_irqsafe(dev->wl->hw, skb, &status);
+	memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
+	ieee80211_rx_irqsafe(dev->wl->hw, skb);
 
 	return;
 drop:

drivers/net/wireless/iwlwifi/iwl-3945.c

@@ -577,7 +577,8 @@ static void iwl3945_pass_packet_to_mac80211(struct iwl_priv *priv,
 	if (ieee80211_is_data(hdr->frame_control))
 		priv->rxtxpackets += len;
 #endif
-	ieee80211_rx_irqsafe(priv->hw, rxb->skb, stats);
+	memcpy(IEEE80211_SKB_RXCB(rxb->skb), stats, sizeof(*stats));
+	ieee80211_rx_irqsafe(priv->hw, rxb->skb);
 	rxb->skb = NULL;
 }
 

drivers/net/wireless/iwlwifi/iwl-rx.c

@@ -932,7 +932,8 @@ static void iwl_pass_packet_to_mac80211(struct iwl_priv *priv,
 		return;
 
 	iwl_update_rx_stats(priv, le16_to_cpu(hdr->frame_control), len);
-	ieee80211_rx_irqsafe(priv->hw, rxb->skb, stats);
+	memcpy(IEEE80211_SKB_RXCB(rxb->skb), stats, sizeof(*stats));
+	ieee80211_rx_irqsafe(priv->hw, rxb->skb);
 	priv->alloc_rxb_skb--;
 	rxb->skb = NULL;
 }

drivers/net/wireless/libertas_tf/main.c

@@ -503,7 +503,8 @@ int lbtf_rx(struct lbtf_private *priv, struct sk_buff *skb)
 		skb_reserve(skb, 2);
 	}
 
-	ieee80211_rx_irqsafe(priv->hw, skb, &stats);
+	memcpy(IEEE80211_SKB_RXCB(skb), &stats, sizeof(stats));
+	ieee80211_rx_irqsafe(priv->hw, skb);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(lbtf_rx);

drivers/net/wireless/mac80211_hwsim.c

@@ -430,7 +430,8 @@ static bool mac80211_hwsim_tx_frame(struct ieee80211_hw *hw,
 		if (memcmp(hdr->addr1, data2->hw->wiphy->perm_addr,
 			   ETH_ALEN) == 0)
 			ack = true;
-		ieee80211_rx_irqsafe(data2->hw, nskb, &rx_status);
+		memcpy(IEEE80211_SKB_RXCB(nskb), &rx_status, sizeof(rx_status));
+		ieee80211_rx_irqsafe(data2->hw, nskb);
 	}
 	spin_unlock(&hwsim_radio_lock);
 

drivers/net/wireless/mwl8k.c

@@ -1047,7 +1047,8 @@ static int rxq_process(struct ieee80211_hw *hw, int index, int limit)
 		status.flag = 0;
 		status.band = IEEE80211_BAND_2GHZ;
 		status.freq = ieee80211_channel_to_frequency(rx_desc->channel);
-		ieee80211_rx_irqsafe(hw, skb, &status);
+		memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
+		ieee80211_rx_irqsafe(hw, skb);
 
 		processed++;
 	}

drivers/net/wireless/p54/p54common.c

@@ -794,7 +794,8 @@ static int p54_rx_data(struct ieee80211_hw *dev, struct sk_buff *skb)
 	skb_pull(skb, header_len);
 	skb_trim(skb, le16_to_cpu(hdr->len));
 
-	ieee80211_rx_irqsafe(dev, skb, &rx_status);
+	memcpy(IEEE80211_SKB_RXCB(skb), &rx_status, sizeof(rx_status));
+	ieee80211_rx_irqsafe(dev, skb);
 
 	queue_delayed_work(dev->workqueue, &priv->work,
 			   msecs_to_jiffies(P54_STATISTICS_UPDATE));

drivers/net/wireless/rt2x00/rt2x00dev.c

@@ -449,7 +449,8 @@ void rt2x00lib_rxdone(struct rt2x00_dev *rt2x00dev,
 	 * mac80211 will clean up the skb structure.
 	 */
 	rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_RXDONE, entry->skb);
-	ieee80211_rx_irqsafe(rt2x00dev->hw, entry->skb, rx_status);
+	memcpy(IEEE80211_SKB_RXCB(entry->skb), rx_status, sizeof(*rx_status));
+	ieee80211_rx_irqsafe(rt2x00dev->hw, entry->skb);
 
 	/*
 	 * Replace the skb with the freshly allocated one.

drivers/net/wireless/rtl818x/rtl8180_dev.c

@@ -143,7 +143,8 @@ static void rtl8180_handle_rx(struct ieee80211_hw *dev)
 			if (flags & RTL818X_RX_DESC_FLAG_CRC32_ERR)
 				rx_status.flag |= RX_FLAG_FAILED_FCS_CRC;
 
-			ieee80211_rx_irqsafe(dev, skb, &rx_status);
+			memcpy(IEEE80211_SKB_RXCB(skb), &rx_status, sizeof(rx_status));
+			ieee80211_rx_irqsafe(dev, skb);
 
 			skb = new_skb;
 			priv->rx_buf[priv->rx_idx] = skb;

drivers/net/wireless/rtl818x/rtl8187_dev.c

@@ -380,7 +380,8 @@ static void rtl8187_rx_cb(struct urb *urb)
 	rx_status.flag |= RX_FLAG_TSFT;
 	if (flags & RTL818X_RX_DESC_FLAG_CRC32_ERR)
 		rx_status.flag |= RX_FLAG_FAILED_FCS_CRC;
-	ieee80211_rx_irqsafe(dev, skb, &rx_status);
+	memcpy(IEEE80211_SKB_RXCB(skb), &rx_status, sizeof(rx_status));
+	ieee80211_rx_irqsafe(dev, skb);
 
 	skb = dev_alloc_skb(RTL8187_MAX_RX);
 	if (unlikely(!skb)) {

drivers/net/wireless/wl12xx/wl1251_rx.c

@@ -151,7 +151,8 @@ static void wl1251_rx_body(struct wl1251 *wl,
 	wl1251_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb, skb->len,
 		     beacon ? "beacon" : "");
 
-	ieee80211_rx(wl->hw, skb, &status);
+	memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
+	ieee80211_rx(wl->hw, skb);
 }
 
 static void wl1251_rx_ack(struct wl1251 *wl)

drivers/net/wireless/zd1211rw/zd_mac.c

@@ -711,7 +711,8 @@ int zd_mac_rx(struct ieee80211_hw *hw, const u8 *buffer, unsigned int length)
 
 	memcpy(skb_put(skb, length), buffer, length);
 
-	ieee80211_rx_irqsafe(hw, skb, &stats);
+	memcpy(IEEE80211_SKB_RXCB(skb), &stats, sizeof(stats));
+	ieee80211_rx_irqsafe(hw, skb);
 	return 0;
 }
 

drivers/staging/agnx/xmit.c

@@ -384,7 +384,8 @@ void handle_rx_irq(struct agnx_priv *priv)
 /*			dump_ieee80211_hdr((struct ieee80211_hdr *)skb->data, "RX G"); */
 		} else
 			agnx_bug("Unknown packets type");
-		ieee80211_rx_irqsafe(priv->hw, skb, &status);
+		memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
+		ieee80211_rx_irqsafe(priv->hw, skb);
 		rx_desc_reinit(priv, i);
 
 	} while (priv->rx.idx++);

drivers/staging/stlc45xx/stlc45xx.c

@@ -1429,7 +1429,8 @@ static int stlc45xx_rx_data(struct stlc45xx *stlc, struct sk_buff *skb)
 	stlc45xx_debug(DEBUG_RX, "rx data 0x%p %d B", skb->data, skb->len);
 	stlc45xx_dump(DEBUG_RX_CONTENT, skb->data, skb->len);
 
-	ieee80211_rx(stlc->hw, skb, &status);
+	memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
+	ieee80211_rx(stlc->hw, skb);
 
 	return 0;
 }

drivers/staging/winbond/wb35rx.c

@@ -40,7 +40,8 @@ static void packet_came(struct ieee80211_hw *hw, char *pRxBufferAddress, int Pac
 	rx_status.phymode = MODE_IEEE80211B;
 */
 
-	ieee80211_rx_irqsafe(hw, skb, &rx_status);
+	memcpy(IEEE80211_SKB_RXCB(skb), &rx_status, sizeof(rx_status));
+	ieee80211_rx_irqsafe(hw, skb);
 }
 
 static void Wb35Rx_adjust(PDESCRIPTOR pRxDes)

include/net/mac80211.h

@@ -397,6 +397,11 @@ static inline struct ieee80211_tx_info *IEEE80211_SKB_CB(struct sk_buff *skb)
 	return (struct ieee80211_tx_info *)skb->cb;
 }
 
+static inline struct ieee80211_rx_status *IEEE80211_SKB_RXCB(struct sk_buff *skb)
+{
+	return (struct ieee80211_rx_status *)skb->cb;
+}
+
 /**
  * ieee80211_tx_info_clear_status - clear TX status
  *
@@ -478,7 +483,7 @@ enum mac80211_rx_flags {
  *
  * The low-level driver should provide this information (the subset
  * supported by hardware) to the 802.11 code with each received
- * frame.
+ * frame, in the skb's control buffer (cb).
  *
  * @mactime: value in microseconds of the 64-bit Time Synchronization Function
  * 	(TSF) timer when the first data symbol (MPDU) arrived at the hardware.
@@ -1606,9 +1611,11 @@ void ieee80211_free_hw(struct ieee80211_hw *hw);
  */
 void ieee80211_restart_hw(struct ieee80211_hw *hw);
 
-/* trick to avoid symbol clashes with the ieee80211 subsystem */
-void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
-		    struct ieee80211_rx_status *status);
+/*
+ * trick to avoid symbol clashes with the ieee80211 subsystem,
+ * use the inline below instead
+ */
+void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb);
 
 /**
  * ieee80211_rx - receive frame
@@ -1624,13 +1631,10 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
  *
  * @hw: the hardware this frame came in on
  * @skb: the buffer to receive, owned by mac80211 after this call
- * @status: status of this frame; the status pointer need not be valid
- *	after this function returns
  */
-static inline void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
-				struct ieee80211_rx_status *status)
+static inline void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
 {
-	__ieee80211_rx(hw, skb, status);
+	__ieee80211_rx(hw, skb);
 }
 
 /**
@@ -1644,13 +1648,8 @@ static inline void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
  *
  * @hw: the hardware this frame came in on
  * @skb: the buffer to receive, owned by mac80211 after this call
- * @status: status of this frame; the status pointer need not be valid
- *	after this function returns and is not freed by mac80211,
- *	it is recommended that it points to a stack area
  */
-void ieee80211_rx_irqsafe(struct ieee80211_hw *hw,
-			  struct sk_buff *skb,
-			  struct ieee80211_rx_status *status);
+void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb);
 
 /**
  * ieee80211_tx_status - transmit status callback

net/mac80211/ibss.c

@@ -705,7 +705,7 @@ static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 	struct ieee80211_mgmt *mgmt;
 	u16 fc;
 
-	rx_status = (struct ieee80211_rx_status *) skb->cb;
+	rx_status = IEEE80211_SKB_RXCB(skb);
 	mgmt = (struct ieee80211_mgmt *) skb->data;
 	fc = le16_to_cpu(mgmt->frame_control);
 
@@ -836,8 +836,7 @@ void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 }
 
 ieee80211_rx_result
-ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
-		       struct ieee80211_rx_status *rx_status)
+ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_mgmt *mgmt;
@@ -852,7 +851,6 @@ ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
 	switch (fc & IEEE80211_FCTL_STYPE) {
 	case IEEE80211_STYPE_PROBE_RESP:
 	case IEEE80211_STYPE_BEACON:
-		memcpy(skb->cb, rx_status, sizeof(*rx_status));
 	case IEEE80211_STYPE_PROBE_REQ:
 	case IEEE80211_STYPE_AUTH:
 		skb_queue_tail(&sdata->u.ibss.skb_queue, skb);

net/mac80211/ieee80211_i.h

@@ -943,8 +943,7 @@ extern const struct iw_handler_def ieee80211_iw_handler_def;
 /* STA code */
 void ieee80211_sta_setup_sdata(struct ieee80211_sub_if_data *sdata);
 ieee80211_rx_result ieee80211_sta_rx_mgmt(struct ieee80211_sub_if_data *sdata,
-					  struct sk_buff *skb,
-					  struct ieee80211_rx_status *rx_status);
+					  struct sk_buff *skb);
 int ieee80211_sta_commit(struct ieee80211_sub_if_data *sdata);
 int ieee80211_sta_set_ssid(struct ieee80211_sub_if_data *sdata, char *ssid, size_t len);
 int ieee80211_sta_get_ssid(struct ieee80211_sub_if_data *sdata, char *ssid, size_t *len);
@@ -967,8 +966,7 @@ void ieee80211_sta_restart(struct ieee80211_sub_if_data *sdata);
 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local);
 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata);
 ieee80211_rx_result
-ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
-		       struct ieee80211_rx_status *rx_status);
+ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb);
 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 					u8 *bssid, u8 *addr, u32 supp_rates);
 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
@@ -988,9 +986,7 @@ int ieee80211_scan_results(struct ieee80211_local *local,
 			   char *buf, size_t len);
 void ieee80211_scan_cancel(struct ieee80211_local *local);
 ieee80211_rx_result
-ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata,
-		  struct sk_buff *skb,
-		  struct ieee80211_rx_status *rx_status);
+ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb);
 int ieee80211_sta_set_extra_ie(struct ieee80211_sub_if_data *sdata,
 			       const char *ie, size_t len);
 

net/mac80211/main.c

@@ -330,19 +330,16 @@ static void ieee80211_tasklet_handler(unsigned long data)
 {
 	struct ieee80211_local *local = (struct ieee80211_local *) data;
 	struct sk_buff *skb;
-	struct ieee80211_rx_status rx_status;
 	struct ieee80211_ra_tid *ra_tid;
 
 	while ((skb = skb_dequeue(&local->skb_queue)) ||
 	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
 		switch (skb->pkt_type) {
 		case IEEE80211_RX_MSG:
-			/* status is in skb->cb */
-			memcpy(&rx_status, skb->cb, sizeof(rx_status));
 			/* Clear skb->pkt_type in order to not confuse kernel
 			 * netstack. */
 			skb->pkt_type = 0;
-			__ieee80211_rx(local_to_hw(local), skb, &rx_status);
+			ieee80211_rx(local_to_hw(local), skb);
 			break;
 		case IEEE80211_TX_STATUS_MSG:
 			skb->pkt_type = 0;

net/mac80211/mesh.c

@@ -568,7 +568,7 @@ static void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 
 	ifmsh = &sdata->u.mesh;
 
-	rx_status = (struct ieee80211_rx_status *) skb->cb;
+	rx_status = IEEE80211_SKB_RXCB(skb);
 	mgmt = (struct ieee80211_mgmt *) skb->data;
 	stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;
 
@@ -671,8 +671,7 @@ void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
 }
 
 ieee80211_rx_result
-ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
-		       struct ieee80211_rx_status *rx_status)
+ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
@@ -689,7 +688,6 @@ ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
 	case IEEE80211_STYPE_PROBE_RESP:
 	case IEEE80211_STYPE_BEACON:
 	case IEEE80211_STYPE_ACTION:
-		memcpy(skb->cb, rx_status, sizeof(*rx_status));
 		skb_queue_tail(&ifmsh->skb_queue, skb);
 		queue_work(local->hw.workqueue, &ifmsh->work);
 		return RX_QUEUED;