mac80211: export the expected throughput

Add get_expected_throughput() API to mac80211 so that each
driver can implement its own version based on the RC
algorithm they are using (might be using an HW RC algo).
The API returns a value expressed in Kbps.

Also, add the new get_expected_throughput() member
to the rate_control_ops structure in order to be
able to query the RC algorithm (this patch provides an
implementation of this API for both minstrel and
minstrel_ht).

The related member in the station_info object is now
filled accordingly when dumping a station.

Cc: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 4e916ad..85c1e74 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -1032,6 +1032,22 @@
 	mac80211_minstrel.free(priv);
 }
 
+static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
+{
+	struct minstrel_ht_sta_priv *msp = priv_sta;
+	struct minstrel_ht_sta *mi = &msp->ht;
+	int i, j;
+
+	if (!msp->is_ht)
+		return mac80211_minstrel.get_expected_throughput(priv_sta);
+
+	i = mi->max_tp_rate / MCS_GROUP_RATES;
+	j = mi->max_tp_rate % MCS_GROUP_RATES;
+
+	/* convert cur_tp from pkt per second in kbps */
+	return mi->groups[i].rates[j].cur_tp * AVG_PKT_SIZE * 8 / 1024;
+}
+
 static const struct rate_control_ops mac80211_minstrel_ht = {
 	.name = "minstrel_ht",
 	.tx_status = minstrel_ht_tx_status,
@@ -1046,6 +1062,7 @@
 	.add_sta_debugfs = minstrel_ht_add_sta_debugfs,
 	.remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
 #endif
+	.get_expected_throughput = minstrel_ht_get_expected_throughput,
 };