cfg80211: Accept multiple RSSI thresholds for CQM

Change the SET CQM command's RSSI threshold attribute to accept any
number of thresholds as a sorted array.  The API should be backwards
compatible so that if one s32 threshold value is passed, the old
mechanism is enabled.  The netlink event generated is the same in both
cases.

cfg80211 handles an arbitrary number of RSSI thresholds but drivers have
to provide a method (set_cqm_rssi_range_config) that configures a range
set by a high and a low value.  Drivers have to call back when the RSSI
goes out of that range and there's no additional event for each time the
range is reconfigured as there was with the current one-threshold API.

This method doesn't have a hysteresis parameter because there's no
benefit to the cfg80211 code from having the hysteresis be handled by
hardware/driver in terms of the number of wakeups.  At the same time
it would likely be less consistent between drivers if offloaded or
done in the drivers.

Signed-off-by: Andrew Zaborowski <andrew.zaborowski@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index ead1aa6d003e..ffc08687b31d 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2712,6 +2712,11 @@ struct cfg80211_nan_func {
  *	the current level is above/below the configured threshold; this may
  *	need some care when the configuration is changed (without first being
  *	disabled.)
+ * @set_cqm_rssi_range_config: Configure two RSSI thresholds in the
+ *	connection quality monitor.  An event is to be sent only when the
+ *	signal level is found to be outside the two values.  The driver should
+ *	set %NL80211_EXT_FEATURE_CQM_RSSI_LIST if this method is implemented.
+ *	If it is provided then there's no point providing @set_cqm_rssi_config.
  * @set_cqm_txe_config: Configure connection quality monitor TX error
  *	thresholds.
  * @sched_scan_start: Tell the driver to start a scheduled scan.
@@ -3001,6 +3006,10 @@ struct cfg80211_ops {
 				       struct net_device *dev,
 				       s32 rssi_thold, u32 rssi_hyst);
 
+	int	(*set_cqm_rssi_range_config)(struct wiphy *wiphy,
+					     struct net_device *dev,
+					     s32 rssi_low, s32 rssi_high);
+
 	int	(*set_cqm_txe_config)(struct wiphy *wiphy,
 				      struct net_device *dev,
 				      u32 rate, u32 pkts, u32 intvl);
@@ -3871,6 +3880,7 @@ void wiphy_free(struct wiphy *wiphy);
 struct cfg80211_conn;
 struct cfg80211_internal_bss;
 struct cfg80211_cached_keys;
+struct cfg80211_cqm_config;
 
 /**
  * struct wireless_dev - wireless device state
@@ -3934,6 +3944,7 @@ struct cfg80211_cached_keys;
  * @event_list: (private) list for internal event processing
  * @event_lock: (private) lock for event list
  * @owner_nlportid: (private) owner socket port ID
+ * @cqm_config: (private) nl80211 RSSI monitor state
  */
 struct wireless_dev {
 	struct wiphy *wiphy;
@@ -4002,6 +4013,8 @@ struct wireless_dev {
 		bool prev_bssid_valid;
 	} wext;
 #endif
+
+	struct cfg80211_cqm_config *cqm_config;
 };
 
 static inline u8 *wdev_address(struct wireless_dev *wdev)