wifi: iwlwifi: disable eSR when BT is active

eSR should be disabled when BT Coex is active and:
- LB link is the primary link.
- LB link is the secondary link and the predicted BT penalty
  (the wifi loss rate caused by BT interference) is higher
  than a given threshold.
If one of the conditions above is no longer true then re-enable eSR.

In order to implement this, add support for version 5 of
BT_PROFILE_NOTIFICATION, in which the bt penalty is provided
by FW.

Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Reviewed-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://msgid.link/20240131225342.b922b6485af8.I7d808ce535a7372aca9cb85c045755e6788a4904@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/intel/iwlwifi/fw/api/coex.h

@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
 /*
+ * Copyright (C) 2023 Intel Corporation
  * Copyright (C) 2013-2014, 2018-2019 Intel Corporation
  * Copyright (C) 2013-2014 Intel Mobile Communications GmbH
  * Copyright (C) 2017 Intel Deutschland GmbH
@@ -170,7 +171,11 @@ enum iwl_bt_ci_compliance {
  * @bt_activity_grading: the activity of BT &enum iwl_bt_activity_grading
  * @ttc_status: is TTC enabled - one bit per PHY
  * @rrc_status: is RRC enabled - one bit per PHY
- * @reserved: reserved
+ * The following fields are only for version 5, and are reserved in version 4:
+ * @wifi_loss_low_rssi: The predicted lost WiFi rate (% of air time that BT is
+ *	utilizing) when the RSSI is low (<= -65 dBm)
+ * @wifi_loss_mid_high_rssi: The predicted lost WiFi rate (% of air time that
+ *	BT is utilizing) when the RSSI is mid/high (>= -65 dBm)
  */
 struct iwl_bt_coex_profile_notif {
 	__le32 mbox_msg[4];
@@ -182,7 +187,10 @@ struct iwl_bt_coex_profile_notif {
 	__le32 bt_activity_grading;
 	u8 ttc_status;
 	u8 rrc_status;
-	__le16 reserved;
-} __packed; /* BT_COEX_PROFILE_NTFY_API_S_VER_4 */
+	u8 wifi_loss_low_rssi;
+	u8 wifi_loss_mid_high_rssi;
+} __packed; /* BT_COEX_PROFILE_NTFY_API_S_VER_4
+	     * BT_COEX_PROFILE_NTFY_API_S_VER_5
+	     */
 
 #endif /* __iwl_fw_api_coex_h__ */

drivers/net/wireless/intel/iwlwifi/mvm/coex.c

@@ -252,6 +252,124 @@ static void iwl_mvm_bt_coex_tcm_based_ci(struct iwl_mvm *mvm,
 	swap(data->primary, data->secondary);
 }
 
+static void iwl_mvm_bt_coex_enable_esr(struct iwl_mvm *mvm,
+				       struct ieee80211_vif *vif, bool enable)
+{
+	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+	int link_id;
+
+	lockdep_assert_held(&mvm->mutex);
+
+	if (!vif->cfg.assoc || !ieee80211_vif_is_mld(vif))
+		return;
+
+	/* Done already */
+	if (mvmvif->bt_coex_esr_disabled == !enable)
+		return;
+
+	mvmvif->bt_coex_esr_disabled = !enable;
+
+	/* Nothing to do */
+	if (mvmvif->esr_active == enable)
+		return;
+
+	if (enable) {
+		/* Try to re-enable eSR*/
+		iwl_mvm_mld_select_links(mvm, vif, false);
+		return;
+	}
+
+	/*
+	 * Find the primary link, as we want to switch to it and drop the
+	 * secondary one.
+	 */
+	link_id = iwl_mvm_mld_get_primary_link(mvm, vif, vif->active_links);
+	WARN_ON(link_id < 0);
+
+	ieee80211_set_active_links_async(vif,
+					 vif->active_links & BIT(link_id));
+}
+
+/*
+ * This function receives the LB link id and checks if eSR should be
+ * enabled or disabled (due to BT coex)
+ */
+bool
+iwl_mvm_bt_coex_calculate_esr_mode(struct iwl_mvm *mvm,
+				   struct ieee80211_vif *vif,
+				   int link_id, int primary_link)
+{
+	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+	struct iwl_mvm_vif_link_info *link_info = mvmvif->link[link_id];
+	bool have_wifi_loss_rate =
+		iwl_fw_lookup_notif_ver(mvm->fw, LEGACY_GROUP,
+					BT_PROFILE_NOTIFICATION, 0) > 4;
+	s8 link_rssi = 0;
+	u8 wifi_loss_rate;
+
+	lockdep_assert_held(&mvm->mutex);
+
+	if (mvm->last_bt_notif.wifi_loss_low_rssi == BT_OFF)
+		return true;
+
+	 /* If LB link is the primary one we should always disable eSR */
+	if (link_id == primary_link)
+		return false;
+
+	/* The feature is not supported */
+	if (!have_wifi_loss_rate)
+		return true;
+
+	/*
+	 * We might not have a link_info when checking whether we can
+	 * (re)enable eSR - the LB link might not exist yet
+	 */
+	if (link_info)
+		link_rssi = (s8)link_info->beacon_stats.avg_signal;
+
+	/*
+	 * In case we don't know the RSSI - take the lower wifi loss,
+	 * so we will more likely enter eSR, and if RSSI is low -
+	 * we will get an update on this and exit eSR.
+	 */
+	if (!link_rssi)
+		wifi_loss_rate = mvm->last_bt_notif.wifi_loss_mid_high_rssi;
+
+	else if (!mvmvif->bt_coex_esr_disabled)
+		 /* RSSI needs to get really low to disable eSR... */
+		wifi_loss_rate =
+			link_rssi <= -IWL_MVM_BT_COEX_DISABLE_ESR_THRESH ?
+				mvm->last_bt_notif.wifi_loss_low_rssi :
+				mvm->last_bt_notif.wifi_loss_mid_high_rssi;
+	else
+		/* ...And really high before we enable it back */
+		wifi_loss_rate =
+			link_rssi <= -IWL_MVM_BT_COEX_ENABLE_ESR_THRESH ?
+				mvm->last_bt_notif.wifi_loss_low_rssi :
+				mvm->last_bt_notif.wifi_loss_mid_high_rssi;
+
+	return wifi_loss_rate <= IWL_MVM_BT_COEX_WIFI_LOSS_THRESH;
+}
+
+void iwl_mvm_bt_coex_update_vif_esr(struct iwl_mvm *mvm,
+				    struct ieee80211_vif *vif,
+				    int link_id)
+{
+	unsigned long usable_links = ieee80211_vif_usable_links(vif);
+	int primary_link = iwl_mvm_mld_get_primary_link(mvm, vif,
+							usable_links);
+	bool enable;
+
+	/* Not assoc, not MLD vif or only one usable link */
+	if (primary_link < 0)
+		return;
+
+	enable = iwl_mvm_bt_coex_calculate_esr_mode(mvm, vif, link_id,
+						    primary_link);
+
+	iwl_mvm_bt_coex_enable_esr(mvm, vif, enable);
+}
+
 static void iwl_mvm_bt_notif_per_link(struct iwl_mvm *mvm,
 				      struct ieee80211_vif *vif,
 				      struct iwl_bt_iterator_data *data,
@@ -297,6 +415,8 @@ static void iwl_mvm_bt_notif_per_link(struct iwl_mvm *mvm,
 		return;
 	}
 
+	iwl_mvm_bt_coex_update_vif_esr(mvm, vif, link_id);
+
 	if (fw_has_capa(&mvm->fw->ucode_capa, IWL_UCODE_TLV_CAPA_COEX_SCHEMA_2))
 		min_ag_for_static_smps = BT_VERY_HIGH_TRAFFIC;
 	else
@@ -432,6 +552,10 @@ static void iwl_mvm_bt_notif_iterator(void *_data, u8 *mac,
 		return;
 	}
 
+	/* When BT is off this will be 0 */
+	if (data->notif->wifi_loss_low_rssi == BT_OFF)
+		iwl_mvm_bt_coex_enable_esr(mvm, vif, true);
+
 	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++)
 		iwl_mvm_bt_notif_per_link(mvm, vif, data, link_id);
 }

drivers/net/wireless/intel/iwlwifi/mvm/constants.h

@@ -11,6 +11,9 @@
 #include "fw-api.h"
 
 #define IWL_MVM_UAPSD_NOAGG_BSSIDS_NUM		20
+#define IWL_MVM_BT_COEX_DISABLE_ESR_THRESH	69
+#define IWL_MVM_BT_COEX_ENABLE_ESR_THRESH	63
+#define IWL_MVM_BT_COEX_WIFI_LOSS_THRESH	0
 
 #define IWL_MVM_DEFAULT_PS_TX_DATA_TIMEOUT	(100 * USEC_PER_MSEC)
 #define IWL_MVM_DEFAULT_PS_RX_DATA_TIMEOUT	(100 * USEC_PER_MSEC)

drivers/net/wireless/intel/iwlwifi/mvm/mld-mac80211.c

@@ -603,6 +603,7 @@ static int iwl_mvm_mld_mac_sta_state(struct ieee80211_hw *hw,
 struct iwl_mvm_link_sel_data {
 	u8 link_id;
 	enum nl80211_band band;
+	enum nl80211_chan_width width;
 	bool active;
 };
 
@@ -655,6 +656,7 @@ void iwl_mvm_mld_select_links(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 
 		data[n_data].link_id = link_id;
 		data[n_data].band = link_conf->chandef.chan->band;
+		data[n_data].width = link_conf->chandef.width;
 		data[n_data].active = vif->active_links & BIT(link_id);
 		n_data++;
 	}
@@ -1215,13 +1217,116 @@ iwl_mvm_mld_change_sta_links(struct ieee80211_hw *hw,
 	return ret;
 }
 
+/*
+ * This function receives a subset of the usable links bitmap and
+ * returns the primary link id, and -1 if such link doesn't exist
+ * (e.g. non-MLO connection) or wasn't found.
+ */
+int iwl_mvm_mld_get_primary_link(struct iwl_mvm *mvm,
+				 struct ieee80211_vif *vif,
+				 unsigned long usable_links)
+{
+	struct iwl_mvm_link_sel_data data[IEEE80211_MLD_MAX_NUM_LINKS];
+	u8 link_id, n_data = 0;
+
+	if (!ieee80211_vif_is_mld(vif) || !vif->cfg.assoc)
+		return -1;
+
+	for_each_set_bit(link_id, &usable_links, IEEE80211_MLD_MAX_NUM_LINKS) {
+		struct ieee80211_bss_conf *link_conf =
+			link_conf_dereference_protected(vif, link_id);
+
+		if (WARN_ON_ONCE(!link_conf))
+			continue;
+
+		data[n_data].link_id = link_id;
+		data[n_data].band = link_conf->chandef.chan->band;
+		data[n_data].width = link_conf->chandef.width;
+		data[n_data].active = true;
+		n_data++;
+	}
+
+	if (n_data <= 1)
+		return -1;
+
+	/* The logic should be modified to handle more than 2 links */
+	WARN_ON_ONCE(n_data > 2);
+
+	/* Primary link is the link with the wider bandwidth or higher band */
+	if (data[0].width > data[1].width)
+		return data[0].link_id;
+	if (data[0].width < data[1].width)
+		return data[1].link_id;
+	if (data[0].band >= data[1].band)
+		return data[0].link_id;
+
+	return data[1].link_id;
+}
+
+/*
+ * This function receives a bitmap of usable links and check if we can enter
+ * eSR on those links.
+ */
+static bool iwl_mvm_can_enter_esr(struct iwl_mvm *mvm,
+				  struct ieee80211_vif *vif,
+				  unsigned long desired_links)
+{
+	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+	int primary_link = iwl_mvm_mld_get_primary_link(mvm, vif,
+							desired_links);
+	bool ret = true;
+	int link_id;
+
+	if (primary_link < 0)
+		return false;
+
+	for_each_set_bit(link_id, &desired_links, IEEE80211_MLD_MAX_NUM_LINKS) {
+		struct ieee80211_bss_conf *link_conf =
+			link_conf_dereference_protected(vif, link_id);
+
+		if (WARN_ON_ONCE(!link_conf))
+			continue;
+
+		/* BT Coex effects eSR mode only if one of the link is on LB */
+		if (link_conf->chandef.chan->band != NL80211_BAND_2GHZ)
+			continue;
+
+		ret = iwl_mvm_bt_coex_calculate_esr_mode(mvm, vif, link_id,
+							 primary_link);
+		// Mark eSR as disabled for the next time
+		if (!ret)
+			mvmvif->bt_coex_esr_disabled = true;
+		break;
+	}
+
+	return ret;
+}
+
 static bool iwl_mvm_mld_can_activate_links(struct ieee80211_hw *hw,
 					   struct ieee80211_vif *vif,
 					   u16 desired_links)
 {
 	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
+	int n_links = hweight16(desired_links);
+	bool ret = true;
+
+	if (n_links <= 1)
+		return true;
 
-	return hweight16(desired_links) <= iwl_mvm_max_active_links(mvm, vif);
+	mutex_lock(&mvm->mutex);
+
+	/* Check if HW supports the wanted number of links */
+	if (n_links > iwl_mvm_max_active_links(mvm, vif)) {
+		ret = false;
+		goto unlock;
+	}
+
+	/* If it is an eSR device, check that we can enter eSR */
+	if (iwl_mvm_is_esr_supported(mvm->fwrt.trans))
+		ret = iwl_mvm_can_enter_esr(mvm, vif, desired_links);
+unlock:
+	mutex_unlock(&mvm->mutex);
+	return ret;
 }
 
 const struct ieee80211_ops iwl_mvm_mld_hw_ops = {

drivers/net/wireless/intel/iwlwifi/mvm/mvm.h

@@ -359,6 +359,7 @@ struct iwl_mvm_vif_link_info {
  * @pm_enabled - indicate if MAC power management is allowed
  * @monitor_active: indicates that monitor context is configured, and that the
  *	interface should get quota etc.
+ * @bt_coex_esr_disabled: indicates if esr is disabled due to bt coex
  * @low_latency: bit flags for low latency
  *	see enum &iwl_mvm_low_latency_cause for causes.
  * @low_latency_actual: boolean, indicates low latency is set,
@@ -389,6 +390,7 @@ struct iwl_mvm_vif {
 	bool pm_enabled;
 	bool monitor_active;
 	bool esr_active;
+	bool bt_coex_esr_disabled;
 
 	u8 low_latency: 6;
 	u8 low_latency_actual: 1;
@@ -1570,13 +1572,17 @@ static inline int iwl_mvm_max_active_links(struct iwl_mvm *mvm,
 					   struct ieee80211_vif *vif)
 {
 	struct iwl_trans *trans = mvm->fwrt.trans;
+	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+
+	lockdep_assert_held(&mvm->mutex);
 
 	if (vif->type == NL80211_IFTYPE_AP)
 		return mvm->fw->ucode_capa.num_beacons;
 
-	if (iwl_mvm_is_esr_supported(trans) ||
-	    (CSR_HW_RFID_TYPE(trans->hw_rf_id) == IWL_CFG_RF_TYPE_FM &&
-	     CSR_HW_RFID_IS_CDB(trans->hw_rf_id)))
+	if ((iwl_mvm_is_esr_supported(trans) &&
+	     !mvmvif->bt_coex_esr_disabled) ||
+	    ((CSR_HW_RFID_TYPE(trans->hw_rf_id) == IWL_CFG_RF_TYPE_FM &&
+	     CSR_HW_RFID_IS_CDB(trans->hw_rf_id))))
 		return IWL_MVM_FW_MAX_ACTIVE_LINKS_NUM;
 
 	return 1;
@@ -2119,6 +2125,12 @@ bool iwl_mvm_bt_coex_is_tpc_allowed(struct iwl_mvm *mvm,
 u8 iwl_mvm_bt_coex_get_single_ant_msk(struct iwl_mvm *mvm, u8 enabled_ants);
 u8 iwl_mvm_bt_coex_tx_prio(struct iwl_mvm *mvm, struct ieee80211_hdr *hdr,
 			   struct ieee80211_tx_info *info, u8 ac);
+bool iwl_mvm_bt_coex_calculate_esr_mode(struct iwl_mvm *mvm,
+					struct ieee80211_vif *vif,
+					int link_id, int primary_link);
+void iwl_mvm_bt_coex_update_vif_esr(struct iwl_mvm *mvm,
+				    struct ieee80211_vif *vif,
+				    int link_id);
 
 /* beacon filtering */
 #ifdef CONFIG_IWLWIFI_DEBUGFS
@@ -2733,4 +2745,7 @@ bool iwl_mvm_enable_fils(struct iwl_mvm *mvm,
 			 struct ieee80211_chanctx_conf *ctx);
 void iwl_mvm_mld_select_links(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 			      bool valid_links_changed);
+int iwl_mvm_mld_get_primary_link(struct iwl_mvm *mvm,
+				 struct ieee80211_vif *vif,
+				 unsigned long usable_links);
 #endif /* __IWL_MVM_H__ */

drivers/net/wireless/intel/iwlwifi/mvm/ops.c

@@ -320,15 +320,16 @@ static const struct iwl_rx_handlers iwl_mvm_rx_handlers[] = {
 		       struct iwl_tlc_update_notif),
 
 	RX_HANDLER(BT_PROFILE_NOTIFICATION, iwl_mvm_rx_bt_coex_notif,
-		   RX_HANDLER_ASYNC_LOCKED, struct iwl_bt_coex_profile_notif),
+		   RX_HANDLER_ASYNC_LOCKED_WIPHY,
+		   struct iwl_bt_coex_profile_notif),
 	RX_HANDLER_NO_SIZE(BEACON_NOTIFICATION, iwl_mvm_rx_beacon_notif,
 			   RX_HANDLER_ASYNC_LOCKED),
 	RX_HANDLER_NO_SIZE(STATISTICS_NOTIFICATION, iwl_mvm_rx_statistics,
 			   RX_HANDLER_ASYNC_LOCKED),
 
 	RX_HANDLER_GRP(STATISTICS_GROUP, STATISTICS_OPER_NOTIF,
 		       iwl_mvm_handle_rx_system_oper_stats,
-		       RX_HANDLER_ASYNC_LOCKED,
+		       RX_HANDLER_ASYNC_LOCKED_WIPHY,
 		       struct iwl_system_statistics_notif_oper),
 	RX_HANDLER_GRP(STATISTICS_GROUP, STATISTICS_OPER_PART1_NOTIF,
 		       iwl_mvm_handle_rx_system_oper_part1_stats,