[PATCH iwlwifi-next 09/15] wifi: iwlwifi: add CQM event support for per-link RSSI changes

[Miri Korenblit <miriam.rachel.korenblit@intel.com>]

From: Avinash Bhatt <avinash.bhatt@intel.com>

Implement CQM RSSI threshold handling by tracking the last reported RSSI
and issuing CQM low/high events when the RSSI crosses the configured
threshold with the required hysteresis. This provides proper CQM support
and enables userspace to receive per-link RSSI notifications.

Signed-off-by: Avinash Bhatt <avinash.bhatt@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Pagadala Yesu Anjaneyulu <pagadala.yesu.anjaneyulu@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
---
 drivers/net/wireless/intel/iwlwifi/mld/link.h |  2 ++
 .../net/wireless/intel/iwlwifi/mld/stats.c    | 26 ++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mld/link.h b/drivers/net/wireless/intel/iwlwifi/mld/link.h
index 9e4da8e4de93..ca691259fc5e 100644
--- a/drivers/net/wireless/intel/iwlwifi/mld/link.h
+++ b/drivers/net/wireless/intel/iwlwifi/mld/link.h
@@ -40,6 +40,7 @@ struct iwl_probe_resp_data {
  * @bcast_sta: station used for broadcast packets. Used in AP, GO and IBSS.
  * @mcast_sta: station used for multicast packets. Used in AP, GO and IBSS.
  * @mon_sta: station used for TX injection in monitor interface.
+ * @last_cqm_rssi_event: rssi of the last cqm rssi event
  * @average_beacon_energy: average beacon energy for beacons received during
  *	client connections
  * @ap_early_keys: The firmware cannot install keys before bcast/mcast STAs,
@@ -66,6 +67,7 @@ struct iwl_mld_link {
 	struct iwl_mld_int_sta bcast_sta;
 	struct iwl_mld_int_sta mcast_sta;
 	struct iwl_mld_int_sta mon_sta;
+	int last_cqm_rssi_event;
 
 	/* we can only have 2 GTK + 2 IGTK + 2 BIGTK active at a time */
 	struct ieee80211_key_conf *ap_early_keys[6];
diff --git a/drivers/net/wireless/intel/iwlwifi/mld/stats.c b/drivers/net/wireless/intel/iwlwifi/mld/stats.c
index 7b8709716324..9b3149b9d2c2 100644
--- a/drivers/net/wireless/intel/iwlwifi/mld/stats.c
+++ b/drivers/net/wireless/intel/iwlwifi/mld/stats.c
@@ -369,15 +369,39 @@ static void iwl_mld_stats_recalc_traffic_load(struct iwl_mld *mld,
 static void iwl_mld_update_link_sig(struct ieee80211_vif *vif, int sig,
 				    struct ieee80211_bss_conf *bss_conf)
 {
+	struct iwl_mld_link *link = iwl_mld_link_from_mac80211(bss_conf);
 	struct iwl_mld *mld = iwl_mld_vif_from_mac80211(vif)->mld;
 	int exit_emlsr_thresh;
+	int last_event;
 
 	if (sig == 0) {
 		IWL_DEBUG_RX(mld, "RSSI is 0 - skip signal based decision\n");
 		return;
 	}
 
-	/* TODO: task=statistics handle CQM notifications */
+	if (WARN_ON(!link))
+		return;
+
+	/* CQM Notification */
+	if (vif->driver_flags & IEEE80211_VIF_SUPPORTS_CQM_RSSI) {
+		int thold = bss_conf->cqm_rssi_thold;
+		int hyst = bss_conf->cqm_rssi_hyst;
+
+		last_event = link->last_cqm_rssi_event;
+		if (thold && sig < thold &&
+		    (last_event == 0 || sig < last_event - hyst)) {
+			link->last_cqm_rssi_event = sig;
+			ieee80211_cqm_rssi_notify(vif,
+						  NL80211_CQM_RSSI_THRESHOLD_EVENT_LOW,
+						  sig, GFP_KERNEL);
+		} else if (sig > thold &&
+			   (last_event == 0 || sig > last_event + hyst)) {
+			link->last_cqm_rssi_event = sig;
+			ieee80211_cqm_rssi_notify(vif,
+						  NL80211_CQM_RSSI_THRESHOLD_EVENT_HIGH,
+						  sig, GFP_KERNEL);
+		}
+	}
 
 	if (!iwl_mld_emlsr_active(vif)) {
 		/* We're not in EMLSR and our signal is bad,
-- 
2.34.1