ath9k: Add routines for switching between active virtual wiphys

ath9k_wiphy_select() can be used to select a virtual wiphy to be
activated. Other virtual wiphys will be paused and once that is done,
the operational channel is changed and the wiphys that are on the
selected channel will be unpaused.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 144 insertions, 3 deletions

diff --git a/drivers/net/wireless/ath9k/virtual.c b/drivers/net/wireless/ath9k/virtual.c
index a8bac97bd84..76ffdfa860e 100644
--- a/drivers/net/wireless/ath9k/virtual.c
+++ b/drivers/net/wireless/ath9k/virtual.c
@@ -222,6 +222,81 @@ exit:
 	return -1;
 }
 
+static bool __ath9k_wiphy_pausing(struct ath_softc *sc)
+{
+	int i;
+	if (sc->pri_wiphy->state == ATH_WIPHY_PAUSING)
+		return true;
+	for (i = 0; i < sc->num_sec_wiphy; i++) {
+		if (sc->sec_wiphy[i] &&
+		    sc->sec_wiphy[i]->state == ATH_WIPHY_PAUSING)
+			return true;
+	}
+	return false;
+}
+
+static bool ath9k_wiphy_pausing(struct ath_softc *sc)
+{
+	bool ret;
+	spin_lock_bh(&sc->wiphy_lock);
+	ret = __ath9k_wiphy_pausing(sc);
+	spin_unlock_bh(&sc->wiphy_lock);
+	return ret;
+}
+
+static int __ath9k_wiphy_unpause(struct ath_wiphy *aphy);
+
+/* caller must hold wiphy_lock */
+static void __ath9k_wiphy_unpause_ch(struct ath_wiphy *aphy)
+{
+	if (aphy == NULL)
+		return;
+	if (aphy->chan_idx != aphy->sc->chan_idx)
+		return; /* wiphy not on the selected channel */
+	__ath9k_wiphy_unpause(aphy);
+}
+
+static void ath9k_wiphy_unpause_channel(struct ath_softc *sc)
+{
+	int i;
+	spin_lock_bh(&sc->wiphy_lock);
+	__ath9k_wiphy_unpause_ch(sc->pri_wiphy);
+	for (i = 0; i < sc->num_sec_wiphy; i++)
+		__ath9k_wiphy_unpause_ch(sc->sec_wiphy[i]);
+	spin_unlock_bh(&sc->wiphy_lock);
+}
+
+void ath9k_wiphy_chan_work(struct work_struct *work)
+{
+	struct ath_softc *sc = container_of(work, struct ath_softc, chan_work);
+	struct ath_wiphy *aphy = sc->next_wiphy;
+
+	if (aphy == NULL)
+		return;
+
+	/*
+	 * All pending interfaces paused; ready to change
+	 * channels.
+	 */
+
+	/* Change channels */
+	mutex_lock(&sc->mutex);
+	/* XXX: remove me eventually */
+	ath9k_update_ichannel(sc, aphy->hw,
+			      &sc->sc_ah->channels[sc->chan_idx]);
+	ath_update_chainmask(sc, sc->chan_is_ht);
+	if (ath_set_channel(sc, aphy->hw,
+			    &sc->sc_ah->channels[sc->chan_idx]) < 0) {
+		printk(KERN_DEBUG "ath9k: Failed to set channel for new "
+		       "virtual wiphy\n");
+		mutex_unlock(&sc->mutex);
+		return;
+	}
+	mutex_unlock(&sc->mutex);
+
+	ath9k_wiphy_unpause_channel(sc);
+}
+
 /*
  * ath9k version of ieee80211_tx_status() for TX frames that are generated
  * internally in the driver.
@@ -244,6 +319,14 @@ void ath9k_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
 			 */
 		}
 		aphy->state = ATH_WIPHY_PAUSED;
+		if (!ath9k_wiphy_pausing(aphy->sc)) {
+			/*
+			 * Drop from tasklet to work to allow mutex for channel
+			 * change.
+			 */
+			queue_work(aphy->sc->hw->workqueue,
+				   &aphy->sc->chan_work);
+		}
 	}
 
 	kfree(tx_info_priv);
@@ -252,6 +335,14 @@ void ath9k_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
 	dev_kfree_skb(skb);
 }
 
+static void ath9k_mark_paused(struct ath_wiphy *aphy)
+{
+	struct ath_softc *sc = aphy->sc;
+	aphy->state = ATH_WIPHY_PAUSED;
+	if (!__ath9k_wiphy_pausing(sc))
+		queue_work(sc->hw->workqueue, &sc->chan_work);
+}
+
 static void ath9k_pause_iter(void *data, u8 *mac, struct ieee80211_vif *vif)
 {
 	struct ath_wiphy *aphy = data;
@@ -260,15 +351,19 @@ static void ath9k_pause_iter(void *data, u8 *mac, struct ieee80211_vif *vif)
 	switch (vif->type) {
 	case NL80211_IFTYPE_STATION:
 		if (!vif->bss_conf.assoc) {
-			aphy->state = ATH_WIPHY_PAUSED;
+			ath9k_mark_paused(aphy);
 			break;
 		}
 		/* TODO: could avoid this if already in PS mode */
-		ath9k_send_nullfunc(aphy, vif, avp->bssid, 1);
+		if (ath9k_send_nullfunc(aphy, vif, avp->bssid, 1)) {
+			printk(KERN_DEBUG "%s: failed to send PS nullfunc\n",
+			       __func__);
+			ath9k_mark_paused(aphy);
+		}
 		break;
 	case NL80211_IFTYPE_AP:
 		/* Beacon transmission is paused by aphy->state change */
-		aphy->state = ATH_WIPHY_PAUSED;
+		ath9k_mark_paused(aphy);
 		break;
 	default:
 		break;
@@ -336,3 +431,49 @@ int ath9k_wiphy_unpause(struct ath_wiphy *aphy)
 	spin_unlock_bh(&aphy->sc->wiphy_lock);
 	return ret;
 }
+
+/* caller must hold wiphy_lock */
+static void __ath9k_wiphy_pause_all(struct ath_softc *sc)
+{
+	int i;
+	if (sc->pri_wiphy->state == ATH_WIPHY_ACTIVE)
+		__ath9k_wiphy_pause(sc->pri_wiphy);
+	for (i = 0; i < sc->num_sec_wiphy; i++) {
+		if (sc->sec_wiphy[i] &&
+		    sc->sec_wiphy[i]->state == ATH_WIPHY_ACTIVE)
+			__ath9k_wiphy_pause(sc->sec_wiphy[i]);
+	}
+}
+
+int ath9k_wiphy_select(struct ath_wiphy *aphy)
+{
+	struct ath_softc *sc = aphy->sc;
+	bool now;
+
+	spin_lock_bh(&sc->wiphy_lock);
+	if (__ath9k_wiphy_pausing(sc)) {
+		spin_unlock_bh(&sc->wiphy_lock);
+		return -EBUSY; /* previous select still in progress */
+	}
+
+	/* Store the new channel */
+	sc->chan_idx = aphy->chan_idx;
+	sc->chan_is_ht = aphy->chan_is_ht;
+	sc->next_wiphy = aphy;
+
+	__ath9k_wiphy_pause_all(sc);
+	now = !__ath9k_wiphy_pausing(aphy->sc);
+	spin_unlock_bh(&sc->wiphy_lock);
+
+	if (now) {
+		/* Ready to request channel change immediately */
+		queue_work(aphy->sc->hw->workqueue, &aphy->sc->chan_work);
+	}
+
+	/*
+	 * wiphys will be unpaused in ath9k_tx_status() once channel has been
+	 * changed if any wiphy needs time to become paused.
+	 */
+
+	return 0;
+}