mac80211: enable TPC through mac80211 stack

Control per packet Transmit Power Control (TPC) in lower drivers
according to TX power settings configured by the user. In particular TPC is
enabled if value passed in enum nl80211_tx_power_setting is
NL80211_TX_POWER_LIMITED (allow using less than specified from userspace),
whereas TPC is disabled if nl80211_tx_power_setting is set to
NL80211_TX_POWER_FIXED (use value configured from userspace)

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -376,6 +376,12 @@ enum ieee80211_rssi_event {
  * @ssid_len: Length of SSID given in @ssid.
  * @hidden_ssid: The SSID of the current vif is hidden. Only valid in AP-mode.
  * @txpower: TX power in dBm
+ * @txpower_type: TX power adjustment used to control per packet Transmit
+ *	Power Control (TPC) in lower driver for the current vif. In particular
+ *	TPC is enabled if value passed in %txpower_type is
+ *	NL80211_TX_POWER_LIMITED (allow using less than specified from
+ *	userspace), whereas TPC is disabled if %txpower_type is set to
+ *	NL80211_TX_POWER_FIXED (use value configured from userspace)
  * @p2p_noa_attr: P2P NoA attribute for P2P powersave
  */
 struct ieee80211_bss_conf {
@@ -411,6 +417,7 @@ struct ieee80211_bss_conf {
 	size_t ssid_len;
 	bool hidden_ssid;
 	int txpower;
+	enum nl80211_tx_power_setting txpower_type;
 	struct ieee80211_p2p_noa_attr p2p_noa_attr;
 };
 

net/mac80211/cfg.c

@@ -2110,6 +2110,8 @@ static int ieee80211_set_tx_power(struct wiphy *wiphy,
 {
 	struct ieee80211_local *local = wiphy_priv(wiphy);
 	struct ieee80211_sub_if_data *sdata;
+	enum nl80211_tx_power_setting txp_type = type;
+	bool update_txp_type = false;
 
 	if (wdev) {
 		sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
@@ -2117,6 +2119,7 @@ static int ieee80211_set_tx_power(struct wiphy *wiphy,
 		switch (type) {
 		case NL80211_TX_POWER_AUTOMATIC:
 			sdata->user_power_level = IEEE80211_UNSET_POWER_LEVEL;
+			txp_type = NL80211_TX_POWER_LIMITED;
 			break;
 		case NL80211_TX_POWER_LIMITED:
 		case NL80211_TX_POWER_FIXED:
@@ -2126,7 +2129,12 @@ static int ieee80211_set_tx_power(struct wiphy *wiphy,
 			break;
 		}
 
-		ieee80211_recalc_txpower(sdata);
+		if (txp_type != sdata->vif.bss_conf.txpower_type) {
+			update_txp_type = true;
+			sdata->vif.bss_conf.txpower_type = txp_type;
+		}
+
+		ieee80211_recalc_txpower(sdata, update_txp_type);
 
 		return 0;
 	}
@@ -2134,6 +2142,7 @@ static int ieee80211_set_tx_power(struct wiphy *wiphy,
 	switch (type) {
 	case NL80211_TX_POWER_AUTOMATIC:
 		local->user_power_level = IEEE80211_UNSET_POWER_LEVEL;
+		txp_type = NL80211_TX_POWER_LIMITED;
 		break;
 	case NL80211_TX_POWER_LIMITED:
 	case NL80211_TX_POWER_FIXED:
@@ -2144,10 +2153,14 @@ static int ieee80211_set_tx_power(struct wiphy *wiphy,
 	}
 
 	mutex_lock(&local->iflist_mtx);
-	list_for_each_entry(sdata, &local->interfaces, list)
+	list_for_each_entry(sdata, &local->interfaces, list) {
 		sdata->user_power_level = local->user_power_level;
+		if (txp_type != sdata->vif.bss_conf.txpower_type)
+			update_txp_type = true;
+		sdata->vif.bss_conf.txpower_type = txp_type;
+	}
 	list_for_each_entry(sdata, &local->interfaces, list)
-		ieee80211_recalc_txpower(sdata);
+		ieee80211_recalc_txpower(sdata, update_txp_type);
 	mutex_unlock(&local->iflist_mtx);
 
 	return 0;

net/mac80211/chan.c

@@ -655,7 +655,7 @@ out:
 	}
 
 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
-		ieee80211_recalc_txpower(sdata);
+		ieee80211_recalc_txpower(sdata, false);
 		ieee80211_recalc_chanctx_min_def(local, new_ctx);
 	}
 
@@ -1387,7 +1387,7 @@ static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
 				ieee80211_bss_info_change_notify(sdata,
 								 changed);
 
-			ieee80211_recalc_txpower(sdata);
+			ieee80211_recalc_txpower(sdata, false);
 		}
 
 		ieee80211_recalc_chanctx_chantype(local, ctx);

net/mac80211/ieee80211_i.h

@@ -1621,7 +1621,8 @@ int ieee80211_add_virtual_monitor(struct ieee80211_local *local);
 void ieee80211_del_virtual_monitor(struct ieee80211_local *local);
 
 bool __ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata);
-void ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata);
+void ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata,
+			      bool update_bss);
 
 static inline bool ieee80211_sdata_running(struct ieee80211_sub_if_data *sdata)
 {

net/mac80211/iface.c

@@ -73,9 +73,10 @@ bool __ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)
 	return false;
 }
 
-void ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)
+void ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata,
+			      bool update_bss)
 {
-	if (__ieee80211_recalc_txpower(sdata))
+	if (__ieee80211_recalc_txpower(sdata) || update_bss)
 		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_TXPOWER);
 }