5 files changed, 125 insertions, 0 deletions

diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index edd2dd7..b2d6bba 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -657,4 +657,12 @@ static inline void drv_set_rekey_data(struct ieee80211_local *local,
 	trace_drv_return_void(local);
 }
 
+static inline void drv_rssi_callback(struct ieee80211_local *local,
+				     const enum ieee80211_rssi_event event)
+{
+	trace_drv_rssi_callback(local, event);
+	if (local->ops->rssi_callback)
+		local->ops->rssi_callback(&local->hw, event);
+	trace_drv_return_void(local);
+}
 #endif /* __MAC80211_DRIVER_OPS */
diff --git a/net/mac80211/driver-trace.h b/net/mac80211/driver-trace.h
index 31a9dfa..4470f6e8 100644
--- a/net/mac80211/driver-trace.h
+++ b/net/mac80211/driver-trace.h
@@ -1052,6 +1052,28 @@ TRACE_EVENT(drv_set_rekey_data,
 		  LOCAL_PR_ARG, VIF_PR_ARG)
 );
 
+TRACE_EVENT(drv_rssi_callback,
+	TP_PROTO(struct ieee80211_local *local,
+		 enum ieee80211_rssi_event rssi_event),
+
+	TP_ARGS(local, rssi_event),
+
+	TP_STRUCT__entry(
+		LOCAL_ENTRY
+		__field(u32, rssi_event)
+	),
+
+	TP_fast_assign(
+		LOCAL_ASSIGN;
+		__entry->rssi_event = rssi_event;
+	),
+
+	TP_printk(
+		LOCAL_PR_FMT " rssi_event:%d",
+		LOCAL_PR_ARG, __entry->rssi_event
+	)
+);
+
 /*
  * Tracing for API calls that drivers call.
  */
@@ -1342,6 +1364,30 @@ TRACE_EVENT(api_gtk_rekey_notify,
 	TP_printk(VIF_PR_FMT, VIF_PR_ARG)
 );
 
+TRACE_EVENT(api_enable_rssi_reports,
+	TP_PROTO(struct ieee80211_sub_if_data *sdata,
+		 int rssi_min_thold, int rssi_max_thold),
+
+	TP_ARGS(sdata, rssi_min_thold, rssi_max_thold),
+
+	TP_STRUCT__entry(
+		VIF_ENTRY
+		__field(int, rssi_min_thold)
+		__field(int, rssi_max_thold)
+	),
+
+	TP_fast_assign(
+		VIF_ASSIGN;
+		__entry->rssi_min_thold = rssi_min_thold;
+		__entry->rssi_max_thold = rssi_max_thold;
+	),
+
+	TP_printk(
+		VIF_PR_FMT " rssi_min_thold =%d, rssi_max_thold = %d",
+		VIF_PR_ARG, __entry->rssi_min_thold, __entry->rssi_max_thold
+	)
+);
+
 /*
  * Tracing for internal functions
  * (which may also be called in response to driver calls)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 4c7a831..96600be 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -432,6 +432,14 @@ struct ieee80211_if_managed {
 	 * generated for the current association.
 	 */
 	int last_cqm_event_signal;
+
+	/*
+	 * State variables for keeping track of RSSI of the AP currently
+	 * connected to and informing driver when RSSI has gone
+	 * below/above a certain threshold.
+	 */
+	int rssi_min_thold, rssi_max_thold;
+	int last_ave_beacon_signal;
 };
 
 struct ieee80211_if_ibss {
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index b6d9bd5..4b0460a 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1763,6 +1763,7 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 		ifmgd->ave_beacon_signal = rx_status->signal * 16;
 		ifmgd->last_cqm_event_signal = 0;
 		ifmgd->count_beacon_signal = 1;
+		ifmgd->last_ave_beacon_signal = 0;
 	} else {
 		ifmgd->ave_beacon_signal =
 			(IEEE80211_SIGNAL_AVE_WEIGHT * rx_status->signal * 16 +
@@ -1770,6 +1771,28 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 			 ifmgd->ave_beacon_signal) / 16;
 		ifmgd->count_beacon_signal++;
 	}
+
+	if (ifmgd->rssi_min_thold != ifmgd->rssi_max_thold &&
+	    ifmgd->count_beacon_signal >= IEEE80211_SIGNAL_AVE_MIN_COUNT) {
+		int sig = ifmgd->ave_beacon_signal;
+		int last_sig = ifmgd->last_ave_beacon_signal;
+
+		/*
+		 * if signal crosses either of the boundaries, invoke callback
+		 * with appropriate parameters
+		 */
+		if (sig > ifmgd->rssi_max_thold &&
+		    (last_sig <= ifmgd->rssi_min_thold || last_sig == 0)) {
+			ifmgd->last_ave_beacon_signal = sig;
+			drv_rssi_callback(local, RSSI_EVENT_HIGH);
+		} else if (sig < ifmgd->rssi_min_thold &&
+			   (last_sig >= ifmgd->rssi_max_thold ||
+			   last_sig == 0)) {
+			ifmgd->last_ave_beacon_signal = sig;
+			drv_rssi_callback(local, RSSI_EVENT_LOW);
+		}
+	}
+
 	if (bss_conf->cqm_rssi_thold &&
 	    ifmgd->count_beacon_signal >= IEEE80211_SIGNAL_AVE_MIN_COUNT &&
 	    !(local->hw.flags & IEEE80211_HW_SUPPORTS_CQM_RSSI)) {
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 652e569..1901320 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1450,3 +1450,43 @@ size_t ieee80211_ie_split_vendor(const u8 *ies, size_t ielen, size_t offset)
 
 	return pos;
 }
+
+static void _ieee80211_enable_rssi_reports(struct ieee80211_sub_if_data *sdata,
+					    int rssi_min_thold,
+					    int rssi_max_thold)
+{
+	trace_api_enable_rssi_reports(sdata, rssi_min_thold, rssi_max_thold);
+
+	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION))
+		return;
+
+	/*
+	 * Scale up threshold values before storing it, as the RSSI averaging
+	 * algorithm uses a scaled up value as well. Change this scaling
+	 * factor if the RSSI averaging algorithm changes.
+	 */
+	sdata->u.mgd.rssi_min_thold = rssi_min_thold*16;
+	sdata->u.mgd.rssi_max_thold = rssi_max_thold*16;
+}
+
+void ieee80211_enable_rssi_reports(struct ieee80211_vif *vif,
+				    int rssi_min_thold,
+				    int rssi_max_thold)
+{
+	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+
+	WARN_ON(rssi_min_thold == rssi_max_thold ||
+		rssi_min_thold > rssi_max_thold);
+
+	_ieee80211_enable_rssi_reports(sdata, rssi_min_thold,
+				       rssi_max_thold);
+}
+EXPORT_SYMBOL(ieee80211_enable_rssi_reports);
+
+void ieee80211_disable_rssi_reports(struct ieee80211_vif *vif)
+{
+	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+
+	_ieee80211_enable_rssi_reports(sdata, 0, 0);
+}
+EXPORT_SYMBOL(ieee80211_disable_rssi_reports);