mac80211: store tx power value from user to station

This patch introduce a new driver callback drv_sta_set_txpwr. This API will
copy the transmit power value passed from user space and call the driver
callback to set the tx power for the station.
Co-developed-by: Balaji Pothunoori <bpothuno@codeaurora.org>
Signed-off-by: Ashok Raj Nagarajan <arnagara@codeaurora.org>
Signed-off-by: Balaji Pothunoori <bpothuno@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -1889,6 +1889,24 @@ struct ieee80211_sta_rates {
 	} rate[IEEE80211_TX_RATE_TABLE_SIZE];
 };
 
+/**
+ * struct ieee80211_sta_txpwr - station txpower configuration
+ *
+ * Used to configure txpower for station.
+ *
+ * @power: indicates the tx power, in dBm, to be used when sending data frames
+ *	to the STA.
+ * @type: In particular if TPC %type is NL80211_TX_POWER_LIMITED then tx power
+ *	will be less than or equal to specified from userspace, whereas if TPC
+ *	%type is NL80211_TX_POWER_AUTOMATIC then it indicates default tx power.
+ *	NL80211_TX_POWER_FIXED is not a valid configuration option for
+ *	per peer TPC.
+ */
+struct ieee80211_sta_txpwr {
+	s16 power;
+	enum nl80211_tx_power_setting type;
+};
+
 /**
  * struct ieee80211_sta - station table entry
  *
@@ -1975,6 +1993,7 @@ struct ieee80211_sta {
 	bool support_p2p_ps;
 	u16 max_rc_amsdu_len;
 	u16 max_tid_amsdu_len[IEEE80211_NUM_TIDS];
+	struct ieee80211_sta_txpwr txpwr;
 
 	struct ieee80211_txq *txq[IEEE80211_NUM_TIDS + 1];
 
@@ -3800,6 +3819,9 @@ struct ieee80211_ops {
 #endif
 	void (*sta_notify)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			enum sta_notify_cmd, struct ieee80211_sta *sta);
+	int (*sta_set_txpwr)(struct ieee80211_hw *hw,
+			     struct ieee80211_vif *vif,
+			     struct ieee80211_sta *sta);
 	int (*sta_state)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			 struct ieee80211_sta *sta,
 			 enum ieee80211_sta_state old_state,

net/mac80211/cfg.c

@@ -1457,6 +1457,15 @@ static int sta_apply_parameters(struct ieee80211_local *local,
 	if (params->listen_interval >= 0)
 		sta->listen_interval = params->listen_interval;
 
+	if (params->sta_modify_mask & STATION_PARAM_APPLY_STA_TXPOWER) {
+		sta->sta.txpwr.type = params->txpwr.type;
+		if (params->txpwr.type == NL80211_TX_POWER_LIMITED)
+			sta->sta.txpwr.power = params->txpwr.power;
+		ret = drv_sta_set_txpwr(local, sdata, sta);
+		if (ret)
+			return ret;
+	}
+
 	if (params->supported_rates) {
 		ieee80211_parse_bitrates(&sdata->vif.bss_conf.chandef,
 					 sband, params->supported_rates,

net/mac80211/driver-ops.c

@@ -138,6 +138,27 @@ int drv_sta_state(struct ieee80211_local *local,
 	return ret;
 }
 
+__must_check
+int drv_sta_set_txpwr(struct ieee80211_local *local,
+		      struct ieee80211_sub_if_data *sdata,
+		      struct sta_info *sta)
+{
+	int ret = -EOPNOTSUPP;
+
+	might_sleep();
+
+	sdata = get_bss_sdata(sdata);
+	if (!check_sdata_in_driver(sdata))
+		return -EIO;
+
+	trace_drv_sta_set_txpwr(local, sdata, &sta->sta);
+	if (local->ops->sta_set_txpwr)
+		ret = local->ops->sta_set_txpwr(&local->hw, &sdata->vif,
+						&sta->sta);
+	trace_drv_return_int(local, ret);
+	return ret;
+}
+
 void drv_sta_rc_update(struct ieee80211_local *local,
 		       struct ieee80211_sub_if_data *sdata,
 		       struct ieee80211_sta *sta, u32 changed)

net/mac80211/driver-ops.h

@@ -529,6 +529,11 @@ int drv_sta_state(struct ieee80211_local *local,
 		  enum ieee80211_sta_state old_state,
 		  enum ieee80211_sta_state new_state);
 
+__must_check
+int drv_sta_set_txpwr(struct ieee80211_local *local,
+		      struct ieee80211_sub_if_data *sdata,
+		      struct sta_info *sta);
+
 void drv_sta_rc_update(struct ieee80211_local *local,
 		       struct ieee80211_sub_if_data *sdata,
 		       struct ieee80211_sta *sta, u32 changed);

net/mac80211/trace.h

@@ -828,6 +828,36 @@ TRACE_EVENT(drv_sta_state,
 	)
 );
 
+TRACE_EVENT(drv_sta_set_txpwr,
+	TP_PROTO(struct ieee80211_local *local,
+		 struct ieee80211_sub_if_data *sdata,
+		 struct ieee80211_sta *sta),
+
+	TP_ARGS(local, sdata, sta),
+
+	TP_STRUCT__entry(
+		LOCAL_ENTRY
+		VIF_ENTRY
+		STA_ENTRY
+		__field(s16, txpwr)
+		__field(u8, type)
+	),
+
+	TP_fast_assign(
+		LOCAL_ASSIGN;
+		VIF_ASSIGN;
+		STA_ASSIGN;
+		__entry->txpwr = sta->txpwr.power;
+		__entry->type = sta->txpwr.type;
+	),
+
+	TP_printk(
+		LOCAL_PR_FMT  VIF_PR_FMT  STA_PR_FMT " txpwr: %d type %d",
+		LOCAL_PR_ARG, VIF_PR_ARG, STA_PR_ARG,
+		__entry->txpwr,  __entry->type
+	)
+);
+
 TRACE_EVENT(drv_sta_rc_update,
 	TP_PROTO(struct ieee80211_local *local,
 		 struct ieee80211_sub_if_data *sdata,