ath10k: rework tx queue locking

Tx queue locking was very simple until now.
Multi-channel support will require a more flexible
and fine grained control.

This introduces a per-hw and per-vif (each with a
bitmask of reasons) tx queue locking.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/core.h

@@ -314,6 +314,7 @@ struct ath10k_vif {
 	enum ath10k_beacon_state beacon_state;
 	void *beacon_buf;
 	dma_addr_t beacon_paddr;
+	unsigned long tx_paused; /* arbitrary values defined by target */
 
 	struct ath10k *ar;
 	struct ieee80211_vif *vif;
@@ -519,6 +520,11 @@ static inline const char *ath10k_scan_state_str(enum ath10k_scan_state state)
 	return "unknown";
 }
 
+enum ath10k_tx_pause_reason {
+	ATH10K_TX_PAUSE_Q_FULL,
+	ATH10K_TX_PAUSE_MAX,
+};
+
 struct ath10k {
 	struct ath_common ath_common;
 	struct ieee80211_hw *hw;
@@ -680,6 +686,8 @@ struct ath10k {
 
 	struct dfs_pattern_detector *dfs_detector;
 
+	unsigned long tx_paused; /* see ATH10K_TX_PAUSE_ */
+
 #ifdef CONFIG_ATH10K_DEBUGFS
 	struct ath10k_debug debug;
 #endif

drivers/net/wireless/ath/ath10k/htt_tx.c

@@ -26,7 +26,7 @@ void __ath10k_htt_tx_dec_pending(struct ath10k_htt *htt)
 {
 	htt->num_pending_tx--;
 	if (htt->num_pending_tx == htt->max_num_pending_tx - 1)
-		ieee80211_wake_queues(htt->ar->hw);
+		ath10k_mac_tx_unlock(htt->ar, ATH10K_TX_PAUSE_Q_FULL);
 }
 
 static void ath10k_htt_tx_dec_pending(struct ath10k_htt *htt)
@@ -49,7 +49,7 @@ static int ath10k_htt_tx_inc_pending(struct ath10k_htt *htt)
 
 	htt->num_pending_tx++;
 	if (htt->num_pending_tx == htt->max_num_pending_tx)
-		ieee80211_stop_queues(htt->ar->hw);
+		ath10k_mac_tx_lock(htt->ar, ATH10K_TX_PAUSE_Q_FULL);
 
 exit:
 	spin_unlock_bh(&htt->tx_lock);

drivers/net/wireless/ath/ath10k/mac.c

@@ -2853,6 +2853,72 @@ static void ath10k_reg_notifier(struct wiphy *wiphy,
 /* TX handlers */
 /***************/
 
+void ath10k_mac_tx_lock(struct ath10k *ar, int reason)
+{
+	lockdep_assert_held(&ar->htt.tx_lock);
+
+	WARN_ON(reason >= ATH10K_TX_PAUSE_MAX);
+	ar->tx_paused |= BIT(reason);
+	ieee80211_stop_queues(ar->hw);
+}
+
+static void ath10k_mac_tx_unlock_iter(void *data, u8 *mac,
+				      struct ieee80211_vif *vif)
+{
+	struct ath10k *ar = data;
+	struct ath10k_vif *arvif = ath10k_vif_to_arvif(vif);
+
+	if (arvif->tx_paused)
+		return;
+
+	ieee80211_wake_queue(ar->hw, arvif->vdev_id);
+}
+
+void ath10k_mac_tx_unlock(struct ath10k *ar, int reason)
+{
+	lockdep_assert_held(&ar->htt.tx_lock);
+
+	WARN_ON(reason >= ATH10K_TX_PAUSE_MAX);
+	ar->tx_paused &= ~BIT(reason);
+
+	if (ar->tx_paused)
+		return;
+
+	ieee80211_iterate_active_interfaces_atomic(ar->hw,
+						   IEEE80211_IFACE_ITER_RESUME_ALL,
+						   ath10k_mac_tx_unlock_iter,
+						   ar);
+}
+
+void ath10k_mac_vif_tx_lock(struct ath10k_vif *arvif, int reason)
+{
+	struct ath10k *ar = arvif->ar;
+
+	lockdep_assert_held(&ar->htt.tx_lock);
+
+	WARN_ON(reason >= BITS_PER_LONG);
+	arvif->tx_paused |= BIT(reason);
+	ieee80211_stop_queue(ar->hw, arvif->vdev_id);
+}
+
+void ath10k_mac_vif_tx_unlock(struct ath10k_vif *arvif, int reason)
+{
+	struct ath10k *ar = arvif->ar;
+
+	lockdep_assert_held(&ar->htt.tx_lock);
+
+	WARN_ON(reason >= BITS_PER_LONG);
+	arvif->tx_paused &= ~BIT(reason);
+
+	if (ar->tx_paused)
+		return;
+
+	if (arvif->tx_paused)
+		return;
+
+	ieee80211_wake_queue(ar->hw, arvif->vdev_id);
+}
+
 static u8 ath10k_tx_h_get_tid(struct ieee80211_hdr *hdr)
 {
 	if (ieee80211_is_mgmt(hdr->frame_control))
@@ -3443,6 +3509,7 @@ void ath10k_halt(struct ath10k *ar)
 		ath10k_monitor_stop(ar);
 
 	ar->monitor_started = false;
+	ar->tx_paused = 0;
 
 	ath10k_scan_finish(ar);
 	ath10k_peer_cleanup_all(ar);
@@ -3862,6 +3929,7 @@ static int ath10k_add_interface(struct ieee80211_hw *hw,
 	int ret = 0;
 	u32 value;
 	int bit;
+	int i;
 	u32 vdev_param;
 
 	vif->driver_flags |= IEEE80211_VIF_SUPPORTS_UAPSD;
@@ -3919,6 +3987,15 @@ static int ath10k_add_interface(struct ieee80211_hw *hw,
 		break;
 	}
 
+	/* Using vdev_id as queue number will make it very easy to do per-vif
+	 * tx queue locking. This shouldn't wrap due to interface combinations
+	 * but do a modulo for correctness sake and prevent using offchannel tx
+	 * queues for regular vif tx.
+	 */
+	vif->cab_queue = arvif->vdev_id % (IEEE80211_MAX_QUEUES - 1);
+	for (i = 0; i < ARRAY_SIZE(vif->hw_queue); i++)
+		vif->hw_queue[i] = arvif->vdev_id % (IEEE80211_MAX_QUEUES - 1);
+
 	/* Some firmware revisions don't wait for beacon tx completion before
 	 * sending another SWBA event. This could lead to hardware using old
 	 * (freed) beacon data in some cases, e.g. tx credit starvation
@@ -6547,7 +6624,8 @@ int ath10k_mac_register(struct ath10k *ar)
 			IEEE80211_HW_SW_CRYPTO_CONTROL |
 			IEEE80211_HW_CONNECTION_MONITOR |
 			IEEE80211_HW_WANT_MONITOR_VIF |
-			IEEE80211_HW_CHANCTX_STA_CSA;
+			IEEE80211_HW_CHANCTX_STA_CSA |
+			IEEE80211_HW_QUEUE_CONTROL;
 
 	ar->hw->wiphy->features |= NL80211_FEATURE_STATIC_SMPS;
 
@@ -6603,7 +6681,13 @@ int ath10k_mac_register(struct ath10k *ar)
 	 * on LL hardware queues are managed entirely by the FW
 	 * so we only advertise to mac we can do the queues thing
 	 */
-	ar->hw->queues = 4;
+	ar->hw->queues = IEEE80211_MAX_QUEUES;
+
+	/* vdev_ids are used as hw queue numbers. Make sure offchan tx queue is
+	 * something that vdev_ids can't reach so that we don't stop the queue
+	 * accidentally.
+	 */
+	ar->hw->offchannel_tx_hw_queue = IEEE80211_MAX_QUEUES - 1;
 
 	switch (ar->wmi.op_version) {
 	case ATH10K_FW_WMI_OP_VERSION_MAIN:

drivers/net/wireless/ath/ath10k/mac.h

@@ -63,6 +63,11 @@ u8 ath10k_mac_hw_rate_to_idx(const struct ieee80211_supported_band *sband,
 u8 ath10k_mac_bitrate_to_idx(const struct ieee80211_supported_band *sband,
 			     u32 bitrate);
 
+void ath10k_mac_tx_lock(struct ath10k *ar, int reason);
+void ath10k_mac_tx_unlock(struct ath10k *ar, int reason);
+void ath10k_mac_vif_tx_lock(struct ath10k_vif *arvif, int reason);
+void ath10k_mac_vif_tx_unlock(struct ath10k_vif *arvif, int reason);
+
 static inline struct ath10k_vif *ath10k_vif_to_arvif(struct ieee80211_vif *vif)
 {
 	return (struct ath10k_vif *)vif->drv_priv;