staging: wfx: simplify the link-id allocation

The "link-id" is a slot number provided to the chip. A link-id is
allocated to every station associated with the chip (mainly when the
chip is in AP mode). It is more or less the same thing than the
association ID, but it is limited to 14 values.

Firmware uses the link-id to track the power save status of the
stations.

The current code try to associate a link-id as soon as data are
exchanged with station. It is far easier to rely on sta_add() and
sta_remove().

Until now the value WFX_LINK_ID_NO_ASSOC, was only used when no more
link-id was available. Now, we also use this value for
not-yet-associated stations (that was its primary behavior).

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200115135338.14374-51-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 18 insertions, 40 deletions

diff --git a/drivers/staging/wfx/sta.c b/drivers/staging/wfx/sta.c
index b7d21540d9a2..75c1e2aecc23 100644
--- a/drivers/staging/wfx/sta.c
+++ b/drivers/staging/wfx/sta.c
@@ -573,28 +573,26 @@ static void wfx_unjoin_work(struct work_struct *work)
 int wfx_sta_add(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 		struct ieee80211_sta *sta)
 {
-	struct wfx_dev *wdev = hw->priv;
 	struct wfx_vif *wvif = (struct wfx_vif *) vif->drv_priv;
 	struct wfx_sta_priv *sta_priv = (struct wfx_sta_priv *) &sta->drv_priv;
-	struct wfx_link_entry *entry;
 
 	spin_lock_init(&sta_priv->lock);
-	if (wvif->vif->type != NL80211_IFTYPE_AP)
-		return 0;
-
 	sta_priv->vif_id = wvif->id;
-	sta_priv->link_id = wfx_find_link_id(wvif, sta->addr);
-	if (!sta_priv->link_id) {
-		dev_warn(wdev->dev, "mo more link-id available\n");
-		return -ENOENT;
-	}
 
-	entry = &wvif->link_id_db[sta_priv->link_id - 1];
+	// FIXME: in station mode, the current API interprets new link-id as a
+	// tdls peer.
+	if (vif->type == NL80211_IFTYPE_STATION)
+		return 0;
+	sta_priv->link_id = ffz(wvif->link_id_map);
+	wvif->link_id_map |= BIT(sta_priv->link_id);
+	WARN_ON(!sta_priv->link_id);
+	WARN_ON(sta_priv->link_id >= WFX_MAX_STA_IN_AP_MODE);
+	hif_map_link(wvif, sta->addr, 0, sta_priv->link_id);
+
 	spin_lock_bh(&wvif->ps_state_lock);
 	if ((sta->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_MASK) ==
 					IEEE80211_WMM_IE_STA_QOSINFO_AC_MASK)
 		wvif->sta_asleep_mask |= BIT(sta_priv->link_id);
-	entry->status = WFX_LINK_HARD;
 	spin_unlock_bh(&wvif->ps_state_lock);
 	return 0;
 }
@@ -602,23 +600,15 @@ int wfx_sta_add(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 int wfx_sta_remove(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 		   struct ieee80211_sta *sta)
 {
-	struct wfx_dev *wdev = hw->priv;
 	struct wfx_vif *wvif = (struct wfx_vif *) vif->drv_priv;
 	struct wfx_sta_priv *sta_priv = (struct wfx_sta_priv *) &sta->drv_priv;
-	struct wfx_link_entry *entry;
 
-	if (wvif->vif->type != NL80211_IFTYPE_AP || !sta_priv->link_id)
+	// FIXME: see note in wfx_sta_add()
+	if (vif->type == NL80211_IFTYPE_STATION)
 		return 0;
-
-	entry = &wvif->link_id_db[sta_priv->link_id - 1];
-	spin_lock_bh(&wvif->ps_state_lock);
-	entry->status = WFX_LINK_RESERVE;
-	entry->timestamp = jiffies;
-	wfx_tx_lock(wdev);
-	if (!schedule_work(&wvif->link_id_work))
-		wfx_tx_unlock(wdev);
-	spin_unlock_bh(&wvif->ps_state_lock);
-	flush_work(&wvif->link_id_work);
+	// FIXME add a mutex?
+	hif_map_link(wvif, sta->addr, 1, sta_priv->link_id);
+	wvif->link_id_map &= ~BIT(sta_priv->link_id);
 	return 0;
 }
 
@@ -627,8 +617,6 @@ static int wfx_start_ap(struct wfx_vif *wvif)
 	int ret;
 
 	wvif->beacon_int = wvif->vif->bss_conf.beacon_int;
-	memset(&wvif->link_id_db, 0, sizeof(wvif->link_id_db));
-
 	wvif->wdev->tx_burst_idx = -1;
 	ret = hif_start(wvif, &wvif->vif->bss_conf, wvif->channel);
 	if (ret)
@@ -861,7 +849,7 @@ static void wfx_ps_notify(struct wfx_vif *wvif, enum sta_notify_cmd notify_cmd,
 		dev_warn(wvif->wdev->dev, "unsupported notify command\n");
 		bit = 0;
 	} else {
-		bit = wvif->link_id_map;
+		bit = wvif->link_id_map & ~1;
 	}
 	prev = wvif->sta_asleep_mask & bit;
 
@@ -1114,9 +1102,7 @@ int wfx_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
 	wvif->vif = vif;
 	wvif->wdev = wdev;
 
-	INIT_WORK(&wvif->link_id_work, wfx_link_id_work);
-	INIT_DELAYED_WORK(&wvif->link_id_gc_work, wfx_link_id_gc_work);
-
+	wvif->link_id_map = 1; // link-id 0 is reserved for multicast
 	spin_lock_init(&wvif->ps_state_lock);
 	INIT_WORK(&wvif->update_tim_work, wfx_update_tim_work);
 
@@ -1171,11 +1157,11 @@ void wfx_remove_interface(struct ieee80211_hw *hw,
 {
 	struct wfx_dev *wdev = hw->priv;
 	struct wfx_vif *wvif = (struct wfx_vif *) vif->drv_priv;
-	int i;
 
 	wait_for_completion_timeout(&wvif->set_pm_mode_complete, msecs_to_jiffies(300));
 
 	mutex_lock(&wdev->conf_mutex);
+	WARN(wvif->link_id_map != 1, "corrupted state");
 	switch (wvif->state) {
 	case WFX_STATE_PRE_STA:
 	case WFX_STATE_STA:
@@ -1185,13 +1171,6 @@ void wfx_remove_interface(struct ieee80211_hw *hw,
 			wfx_tx_unlock(wdev);
 		break;
 	case WFX_STATE_AP:
-		for (i = 0; wvif->link_id_map; ++i) {
-			if (wvif->link_id_map & BIT(i)) {
-				wfx_unmap_link(wvif, i);
-				wvif->link_id_map &= ~BIT(i);
-			}
-		}
-		memset(wvif->link_id_db, 0, sizeof(wvif->link_id_db));
 		wvif->sta_asleep_mask = 0;
 		wvif->mcast_tx = false;
 		wvif->aid0_bit_set = false;
@@ -1213,7 +1192,6 @@ void wfx_remove_interface(struct ieee80211_hw *hw,
 
 	wfx_cqm_bssloss_sm(wvif, 0, 0, 0);
 	cancel_work_sync(&wvif->unjoin_work);
-	cancel_delayed_work_sync(&wvif->link_id_gc_work);
 	del_timer_sync(&wvif->mcast_timeout);
 	wfx_free_event_queue(wvif);