mac80211: move txrate_idx into RC algorithms

The sta_info->txrate_idx member isn't used by all RC algorithms
in the way it was intended to be used, move it into those that
require it (only PID) and keep track in the core code of which
rate was last used for reporting to userspace and the mesh MLME.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

6 files changed, 27 insertions, 18 deletions

diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index 15a5c99..501c783 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -223,7 +223,7 @@ static u32 airtime_link_metric_get(struct ieee80211_local *local,
 	/* bitrate is in units of 100 Kbps, while we need rate in units of
 	 * 1Mbps. This will be corrected on tx_time computation.
 	 */
-	rate = sband->bitrates[sta->txrate_idx].bitrate;
+	rate = sband->bitrates[sta->last_txrate_idx].bitrate;
 	tx_time = (device_constant + 10 * test_frame_len / rate);
 	estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
 	result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
diff --git a/net/mac80211/rc80211_pid.h b/net/mac80211/rc80211_pid.h
index 0a9135b..ffafc5d 100644
--- a/net/mac80211/rc80211_pid.h
+++ b/net/mac80211/rc80211_pid.h
@@ -180,6 +180,8 @@ struct rc_pid_sta_info {
 	u32 tx_num_failed;
 	u32 tx_num_xmit;
 
+	int txrate_idx;
+
 	/* Average failed frames percentage error (i.e. actual vs. target
 	 * percentage), scaled by RC_PID_SMOOTHING. This value is computed
 	 * using using an exponential weighted average technique:
diff --git a/net/mac80211/rc80211_pid_algo.c b/net/mac80211/rc80211_pid_algo.c
index 24e44f5..bc1c456 100644
--- a/net/mac80211/rc80211_pid_algo.c
+++ b/net/mac80211/rc80211_pid_algo.c
@@ -75,7 +75,8 @@ static void rate_control_pid_adjust_rate(struct ieee80211_local *local,
 	struct ieee80211_sub_if_data *sdata;
 	struct ieee80211_supported_band *sband;
 	int cur_sorted, new_sorted, probe, tmp, n_bitrates, band;
-	int cur = sta->txrate_idx;
+	struct rc_pid_sta_info *spinfo = (void *)sta->rate_ctrl_priv;
+	int cur = spinfo->txrate_idx;
 
 	sdata = sta->sdata;
 	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
@@ -111,7 +112,7 @@ static void rate_control_pid_adjust_rate(struct ieee80211_local *local,
 	/* Fit the rate found to the nearest supported rate. */
 	do {
 		if (rate_supported(sta, band, rinfo[tmp].index)) {
-			sta->txrate_idx = rinfo[tmp].index;
+			spinfo->txrate_idx = rinfo[tmp].index;
 			break;
 		}
 		if (adj < 0)
@@ -121,9 +122,9 @@ static void rate_control_pid_adjust_rate(struct ieee80211_local *local,
 	} while (tmp < n_bitrates && tmp >= 0);
 
 #ifdef CONFIG_MAC80211_DEBUGFS
-	rate_control_pid_event_rate_change(
-		&((struct rc_pid_sta_info *)sta->rate_ctrl_priv)->events,
-		sta->txrate_idx, sband->bitrates[sta->txrate_idx].bitrate);
+	rate_control_pid_event_rate_change(&spinfo->events,
+		spinfo->txrate_idx,
+		sband->bitrates[spinfo->txrate_idx].bitrate);
 #endif
 }
 
@@ -190,16 +191,16 @@ static void rate_control_pid_sample(struct rc_pid_info *pinfo,
 	spinfo->tx_num_failed = 0;
 
 	/* If we just switched rate, update the rate behaviour info. */
-	if (pinfo->oldrate != sta->txrate_idx) {
+	if (pinfo->oldrate != spinfo->txrate_idx) {
 
 		i = rinfo[pinfo->oldrate].rev_index;
-		j = rinfo[sta->txrate_idx].rev_index;
+		j = rinfo[spinfo->txrate_idx].rev_index;
 
 		tmp = (pf - spinfo->last_pf);
 		tmp = RC_PID_DO_ARITH_RIGHT_SHIFT(tmp, RC_PID_ARITH_SHIFT);
 
 		rinfo[j].diff = rinfo[i].diff + tmp;
-		pinfo->oldrate = sta->txrate_idx;
+		pinfo->oldrate = spinfo->txrate_idx;
 	}
 	rate_control_pid_normalize(pinfo, sband->n_bitrates);
 
@@ -252,19 +253,20 @@ static void rate_control_pid_tx_status(void *priv, struct net_device *dev,
 	if (!sta)
 		goto unlock;
 
+	spinfo = sta->rate_ctrl_priv;
+
 	/* Don't update the state if we're not controlling the rate. */
 	sdata = sta->sdata;
 	if (sdata->force_unicast_rateidx > -1) {
-		sta->txrate_idx = sdata->max_ratectrl_rateidx;
+		spinfo->txrate_idx = sdata->max_ratectrl_rateidx;
 		goto unlock;
 	}
 
 	/* Ignore all frames that were sent with a different rate than the rate
 	 * we currently advise mac80211 to use. */
-	if (info->tx_rate_idx != sta->txrate_idx)
+	if (info->tx_rate_idx != spinfo->txrate_idx)
 		goto unlock;
 
-	spinfo = sta->rate_ctrl_priv;
 	spinfo->tx_num_xmit++;
 
 #ifdef CONFIG_MAC80211_DEBUGFS
@@ -301,6 +303,7 @@ static void rate_control_pid_get_rate(void *priv, struct net_device *dev,
 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 	struct ieee80211_sub_if_data *sdata;
+	struct rc_pid_sta_info *spinfo;
 	struct sta_info *sta;
 	int rateidx;
 	u16 fc;
@@ -321,10 +324,11 @@ static void rate_control_pid_get_rate(void *priv, struct net_device *dev,
 
 	/* If a forced rate is in effect, select it. */
 	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	spinfo = (struct rc_pid_sta_info *)sta->rate_ctrl_priv;
 	if (sdata->force_unicast_rateidx > -1)
-		sta->txrate_idx = sdata->force_unicast_rateidx;
+		spinfo->txrate_idx = sdata->force_unicast_rateidx;
 
-	rateidx = sta->txrate_idx;
+	rateidx = spinfo->txrate_idx;
 
 	if (rateidx >= sband->n_bitrates)
 		rateidx = sband->n_bitrates - 1;
@@ -349,9 +353,10 @@ static void rate_control_pid_rate_init(void *priv, void *priv_sta,
 	 * Until that method is implemented, we will use the lowest supported
 	 * rate as a workaround. */
 	struct ieee80211_supported_band *sband;
+	struct rc_pid_sta_info *spinfo = (void *)sta->rate_ctrl_priv;
 
 	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
-	sta->txrate_idx = rate_lowest_index(local, sband, sta);
+	spinfo->txrate_idx = rate_lowest_index(local, sband, sta);
 	sta->fail_avg = 0;
 }
 
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 4dafa04..5d8fabf 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -274,7 +274,7 @@ struct sta_info {
 	unsigned long tx_packets;
 	unsigned long tx_bytes;
 	unsigned long tx_fragments;
-	int txrate_idx;
+	unsigned int last_txrate_idx;
 	u16 tid_seq[IEEE80211_QOS_CTL_TID_MASK + 1];
 #ifdef CONFIG_MAC80211_DEBUG_COUNTERS
 	unsigned int wme_tx_queue[NUM_RX_DATA_QUEUES];
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 07bf228..7468495 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -485,6 +485,8 @@ ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
 
 	if (likely(tx->rate_idx < 0)) {
 		rate_control_get_rate(tx->dev, sband, tx->skb, &rsel);
+		if (tx->sta)
+			tx->sta->last_txrate_idx = rsel.rate_idx;
 		tx->rate_idx = rsel.rate_idx;
 		if (unlikely(rsel.probe_idx >= 0)) {
 			info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
diff --git a/net/mac80211/wext.c b/net/mac80211/wext.c
index aef9707..7e0d53a 100644
--- a/net/mac80211/wext.c
+++ b/net/mac80211/wext.c
@@ -636,8 +636,8 @@ static int ieee80211_ioctl_giwrate(struct net_device *dev,
 
 	sta = sta_info_get(local, sdata->u.sta.bssid);
 
-	if (sta && sta->txrate_idx < sband->n_bitrates)
-		rate->value = sband->bitrates[sta->txrate_idx].bitrate;
+	if (sta && sta->last_txrate_idx < sband->n_bitrates)
+		rate->value = sband->bitrates[sta->last_txrate_idx].bitrate;
 	else
 		rate->value = 0;