mac80211: support use of NAPI for bottom-half processing

This patch implement basic infrastructure to support use of NAPI by
mac80211-based hardware drivers.

Because mac80211 devices can support multiple netdevs, a dummy netdev
is used for interfacing with the NAPI code in the core of the network
stack.  That structure is hidden from the hardware drivers, but the
actual napi_struct is exposed in the ieee80211_hw structure so that the
poll routines in drivers can retrieve that structure.  Hardware drivers
can also specify their own weight value for NAPI polling.

Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index b0787a1dea90..3f1e03b521ec 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1102,6 +1102,10 @@ enum ieee80211_hw_flags {
  *
  * @max_rates: maximum number of alternate rate retry stages
  * @max_rate_tries: maximum number of tries for each stage
+ *
+ * @napi_weight: weight used for NAPI polling.  You must specify an
+ *      appropriate value here if a napi_poll operation is provided
+ *      by your driver.
  */
 struct ieee80211_hw {
         struct ieee80211_conf conf;
@@ -1113,6 +1117,7 @@ struct ieee80211_hw {
         int channel_change_time;
         int vif_data_size;
         int sta_data_size;
+        int napi_weight;
         u16 queues;
         u16 max_listen_interval;
         s8 max_signal;
@@ -1687,6 +1692,8 @@ enum ieee80211_ampdu_mlme_action {
  *      switch operation for CSAs received from the AP may implement this
  *      callback. They must then call ieee80211_chswitch_done() to indicate
  *      completion of the channel switch.
+ *
+ * @napi_poll: Poll Rx queue for incoming data frames.
  */
 struct ieee80211_ops {
         int (*tx)(struct ieee80211_hw *hw, struct sk_buff *skb);
@@ -1752,6 +1759,7 @@ struct ieee80211_ops {
         void (*flush)(struct ieee80211_hw *hw, bool drop);
         void (*channel_switch)(struct ieee80211_hw *hw,
                                struct ieee80211_channel_switch *ch_switch);
+        int (*napi_poll)(struct ieee80211_hw *hw, int budget);
 };
 
 /**
@@ -1897,6 +1905,22 @@ void ieee80211_free_hw(struct ieee80211_hw *hw);
  */
 void ieee80211_restart_hw(struct ieee80211_hw *hw);
 
+/** ieee80211_napi_schedule - schedule NAPI poll
+ *
+ * Use this function to schedule NAPI polling on a device.
+ *
+ * @hw: the hardware to start polling
+ */
+void ieee80211_napi_schedule(struct ieee80211_hw *hw);
+
+/** ieee80211_napi_complete - complete NAPI polling
+ *
+ * Use this function to finish NAPI polling on a device.
+ *
+ * @hw: the hardware to stop polling
+ */
+void ieee80211_napi_complete(struct ieee80211_hw *hw);
+
 /**
  * ieee80211_rx - receive frame
  *