mac80211: add offload channel switch support

This adds support for offloading the channel switch
operation to devices that support such, typically
by having specific firmware API for it. The reasons
for this could be that the firmware provides better
timing or that regulatory enforcement done by the
device requires special handling of CSAs.

In order to allow drivers to specify the timing to
the device, the new channel_switch callback will
pass through the received frame's mactime, where
available.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 9448a5b1bb15..389e86a54fc4 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -712,6 +712,28 @@ struct ieee80211_conf {
 };
 
 /**
+ * struct ieee80211_channel_switch - holds the channel switch data
+ *
+ * The information provided in this structure is required for channel switch
+ * operation.
+ *
+ * @timestamp: value in microseconds of the 64-bit Time Synchronization
+ *      Function (TSF) timer when the frame containing the channel switch
+ *      announcement was received. This is simply the rx.mactime parameter
+ *      the driver passed into mac80211.
+ * @block_tx: Indicates whether transmission must be blocked before the
+ *      scheduled channel switch, as indicated by the AP.
+ * @channel: the new channel to switch to
+ * @count: the number of TBTT's until the channel switch event
+ */
+struct ieee80211_channel_switch {
+        u64 timestamp;
+        bool block_tx;
+        struct ieee80211_channel *channel;
+        u8 count;
+};
+
+/**
  * struct ieee80211_vif - per-interface data
  *
  * Data in this structure is continually present for driver
@@ -1631,6 +1653,11 @@ enum ieee80211_ampdu_mlme_action {
  * @flush: Flush all pending frames from the hardware queue, making sure
  *      that the hardware queues are empty. If the parameter @drop is set
  *      to %true, pending frames may be dropped. The callback can sleep.
+ *
+ * @channel_switch: Drivers that need (or want) to offload the channel
+ *      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.
  */
 struct ieee80211_ops {
         int (*tx)(struct ieee80211_hw *hw, struct sk_buff *skb);
@@ -1694,6 +1721,8 @@ struct ieee80211_ops {
         int (*testmode_cmd)(struct ieee80211_hw *hw, void *data, int len);
 #endif
         void (*flush)(struct ieee80211_hw *hw, bool drop);
+        void (*channel_switch)(struct ieee80211_hw *hw,
+                               struct ieee80211_channel_switch *ch_switch);
 };
 
 /**
@@ -2444,6 +2473,16 @@ void ieee80211_cqm_rssi_notify(struct ieee80211_vif *vif,
                                enum nl80211_cqm_rssi_threshold_event rssi_event,
                                gfp_t gfp);
 
+/**
+ * ieee80211_chswitch_done - Complete channel switch process
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
+ * @success: make the channel switch successful or not
+ *
+ * Complete the channel switch post-process: set the new operational channel
+ * and wake up the suspended queues.
+ */
+void ieee80211_chswitch_done(struct ieee80211_vif *vif, bool success);
+
 /* Rate control API */
 
 /**