iwlwifi: mvm: support mac80211 TXQs model

Move to use the new mac80211 TXQs implementation. This has
quite a few benefits for us. We can get rid of the awkward
mapping of DQA to mac80211 queues. We can stop buffering
traffic while waiting for the queue to be allocated. We can
also use mac80211 AMSDUs instead of building it ourselves.

The usage is pretty simple:
Each ieee80211_txq contains iwl_mvm_txq. There is such a
queue for each TID, and one for management frames. We keep
having static AP queues for probes and non-bufferable MMPDUs,
along with broadcast and multicast queues. Those are being
used from the "old" TX invocation path - iwl_mvm_mac_tx.

When there is a new frame in a TXQ, iwl_mvm_mac_wake_tx is
being called, and either invokes the TX path, or allocates
the queue if it does not exist.

Most of the TX path is left untouched, although we can consider
cleaning it up some more, for example get rid of the duplication
of txq_id in both iwl_mvm_txq and iwl_mvm_dqa_txq_info.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

1 files changed, 80 insertions, 33 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index 310a36dd33cf..58bb92b0ef05 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -425,7 +425,6 @@ int iwl_mvm_mac_setup_register(struct iwl_mvm *mvm)
 	ieee80211_hw_set(hw, SIGNAL_DBM);
 	ieee80211_hw_set(hw, SPECTRUM_MGMT);
 	ieee80211_hw_set(hw, REPORTS_TX_ACK_STATUS);
-	ieee80211_hw_set(hw, QUEUE_CONTROL);
 	ieee80211_hw_set(hw, WANT_MONITOR_VIF);
 	ieee80211_hw_set(hw, SUPPORTS_PS);
 	ieee80211_hw_set(hw, SUPPORTS_DYNAMIC_PS);
@@ -439,6 +438,8 @@ int iwl_mvm_mac_setup_register(struct iwl_mvm *mvm)
 	ieee80211_hw_set(hw, NEEDS_UNIQUE_STA_ADDR);
 	ieee80211_hw_set(hw, DEAUTH_NEED_MGD_TX_PREP);
 	ieee80211_hw_set(hw, SUPPORTS_VHT_EXT_NSS_BW);
+	ieee80211_hw_set(hw, BUFF_MMPDU_TXQ);
+	ieee80211_hw_set(hw, STA_MMPDU_TXQ);
 
 	if (iwl_mvm_has_tlc_offload(mvm)) {
 		ieee80211_hw_set(hw, TX_AMPDU_SETUP_IN_HW);
@@ -549,6 +550,7 @@ int iwl_mvm_mac_setup_register(struct iwl_mvm *mvm)
 	hw->sta_data_size = sizeof(struct iwl_mvm_sta);
 	hw->vif_data_size = sizeof(struct iwl_mvm_vif);
 	hw->chanctx_data_size = sizeof(u16);
+	hw->txq_data_size = sizeof(struct iwl_mvm_txq);
 
 	hw->wiphy->interface_modes = BIT(NL80211_IFTYPE_STATION) |
 		BIT(NL80211_IFTYPE_P2P_CLIENT) |
@@ -798,7 +800,6 @@ static bool iwl_mvm_defer_tx(struct iwl_mvm *mvm,
 		goto out;
 
 	__skb_queue_tail(&mvm->d0i3_tx, skb);
-	ieee80211_stop_queues(mvm->hw);
 
 	/* trigger wakeup */
 	iwl_mvm_ref(mvm, IWL_MVM_REF_TX);
@@ -818,13 +819,15 @@ static void iwl_mvm_mac_tx(struct ieee80211_hw *hw,
 	struct ieee80211_sta *sta = control->sta;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct ieee80211_hdr *hdr = (void *)skb->data;
+	bool offchannel = IEEE80211_SKB_CB(skb)->flags &
+		IEEE80211_TX_CTL_TX_OFFCHAN;
 
 	if (iwl_mvm_is_radio_killed(mvm)) {
 		IWL_DEBUG_DROP(mvm, "Dropping - RF/CT KILL\n");
 		goto drop;
 	}
 
-	if (info->hw_queue == IWL_MVM_OFFCHANNEL_QUEUE &&
+	if (offchannel &&
 	    !test_bit(IWL_MVM_STATUS_ROC_RUNNING, &mvm->status) &&
 	    !test_bit(IWL_MVM_STATUS_ROC_AUX_RUNNING, &mvm->status))
 		goto drop;
@@ -837,8 +840,8 @@ static void iwl_mvm_mac_tx(struct ieee80211_hw *hw,
 		sta = NULL;
 
 	/* If there is no sta, and it's not offchannel - send through AP */
-	if (info->control.vif->type == NL80211_IFTYPE_STATION &&
-	    info->hw_queue != IWL_MVM_OFFCHANNEL_QUEUE && !sta) {
+	if (!sta && info->control.vif->type == NL80211_IFTYPE_STATION &&
+	    !offchannel) {
 		struct iwl_mvm_vif *mvmvif =
 			iwl_mvm_vif_from_mac80211(info->control.vif);
 		u8 ap_sta_id = READ_ONCE(mvmvif->ap_sta_id);
@@ -866,6 +869,77 @@ static void iwl_mvm_mac_tx(struct ieee80211_hw *hw,
 	ieee80211_free_txskb(hw, skb);
 }
 
+void iwl_mvm_mac_itxq_xmit(struct ieee80211_hw *hw, struct ieee80211_txq *txq)
+{
+	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
+	struct iwl_mvm_txq *mvmtxq = iwl_mvm_txq_from_mac80211(txq);
+	struct sk_buff *skb = NULL;
+
+	spin_lock(&mvmtxq->tx_path_lock);
+
+	rcu_read_lock();
+	while (likely(!mvmtxq->stopped &&
+		      (mvm->trans->system_pm_mode ==
+		       IWL_PLAT_PM_MODE_DISABLED))) {
+		skb = ieee80211_tx_dequeue(hw, txq);
+
+		if (!skb)
+			break;
+
+		if (!txq->sta)
+			iwl_mvm_tx_skb_non_sta(mvm, skb);
+		else
+			iwl_mvm_tx_skb(mvm, skb, txq->sta);
+	}
+	rcu_read_unlock();
+
+	spin_unlock(&mvmtxq->tx_path_lock);
+}
+
+static void iwl_mvm_mac_wake_tx_queue(struct ieee80211_hw *hw,
+				      struct ieee80211_txq *txq)
+{
+	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
+	struct iwl_mvm_txq *mvmtxq = iwl_mvm_txq_from_mac80211(txq);
+
+	/*
+	 * Please note that racing is handled very carefully here:
+	 * mvmtxq->txq_id is updated during allocation, and mvmtxq->list is
+	 * deleted afterwards.
+	 * This means that if:
+	 * mvmtxq->txq_id != INVALID_QUEUE && list_empty(&mvmtxq->list):
+	 *	queue is allocated and we can TX.
+	 * mvmtxq->txq_id != INVALID_QUEUE && !list_empty(&mvmtxq->list):
+	 *	a race, should defer the frame.
+	 * mvmtxq->txq_id == INVALID_QUEUE && list_empty(&mvmtxq->list):
+	 *	need to allocate the queue and defer the frame.
+	 * mvmtxq->txq_id == INVALID_QUEUE && !list_empty(&mvmtxq->list):
+	 *	queue is already scheduled for allocation, no need to allocate,
+	 *	should defer the frame.
+	 */
+
+	/* If the queue is allocated TX and return. */
+	if (!txq->sta || mvmtxq->txq_id != IWL_MVM_INVALID_QUEUE) {
+		/*
+		 * Check that list is empty to avoid a race where txq_id is
+		 * already updated, but the queue allocation work wasn't
+		 * finished
+		 */
+		if (unlikely(txq->sta && !list_empty(&mvmtxq->list)))
+			return;
+
+		iwl_mvm_mac_itxq_xmit(hw, txq);
+		return;
+	}
+
+	/* The list is being deleted only after the queue is fully allocated. */
+	if (!list_empty(&mvmtxq->list))
+		return;
+
+	list_add_tail(&mvmtxq->list, &mvm->add_stream_txqs);
+	schedule_work(&mvm->add_stream_wk);
+}
+
 static inline bool iwl_enable_rx_ampdu(const struct iwl_cfg *cfg)
 {
 	if (iwlwifi_mod_params.disable_11n & IWL_DISABLE_HT_RXAGG)
@@ -1107,7 +1181,6 @@ static void iwl_mvm_restart_cleanup(struct iwl_mvm *mvm)
 
 	iwl_mvm_reset_phy_ctxts(mvm);
 	memset(mvm->fw_key_table, 0, sizeof(mvm->fw_key_table));
-	memset(mvm->sta_deferred_frames, 0, sizeof(mvm->sta_deferred_frames));
 	memset(&mvm->last_bt_notif, 0, sizeof(mvm->last_bt_notif));
 	memset(&mvm->last_bt_ci_cmd, 0, sizeof(mvm->last_bt_ci_cmd));
 
@@ -2883,32 +2956,6 @@ iwl_mvm_tdls_check_trigger(struct iwl_mvm *mvm,
 				peer_addr, action);
 }
 
-static void iwl_mvm_purge_deferred_tx_frames(struct iwl_mvm *mvm,
-					     struct iwl_mvm_sta *mvm_sta)
-{
-	struct iwl_mvm_tid_data *tid_data;
-	struct sk_buff *skb;
-	int i;
-
-	spin_lock_bh(&mvm_sta->lock);
-	for (i = 0; i <= IWL_MAX_TID_COUNT; i++) {
-		tid_data = &mvm_sta->tid_data[i];
-
-		while ((skb = __skb_dequeue(&tid_data->deferred_tx_frames))) {
-			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-
-			/*
-			 * The first deferred frame should've stopped the MAC
-			 * queues, so we should never get a second deferred
-			 * frame for the RA/TID.
-			 */
-			iwl_mvm_start_mac_queues(mvm, BIT(info->hw_queue));
-			ieee80211_free_txskb(mvm->hw, skb);
-		}
-	}
-	spin_unlock_bh(&mvm_sta->lock);
-}
-
 static int iwl_mvm_mac_sta_state(struct ieee80211_hw *hw,
 				 struct ieee80211_vif *vif,
 				 struct ieee80211_sta *sta,
@@ -2942,7 +2989,6 @@ static int iwl_mvm_mac_sta_state(struct ieee80211_hw *hw,
 	 */
 	if (old_state == IEEE80211_STA_NONE &&
 	    new_state == IEEE80211_STA_NOTEXIST) {
-		iwl_mvm_purge_deferred_tx_frames(mvm, mvm_sta);
 		flush_work(&mvm->add_stream_wk);
 
 		/*
@@ -4680,6 +4726,7 @@ static void iwl_mvm_sync_rx_queues(struct ieee80211_hw *hw)
 
 const struct ieee80211_ops iwl_mvm_hw_ops = {
 	.tx = iwl_mvm_mac_tx,
+	.wake_tx_queue = iwl_mvm_mac_wake_tx_queue,
 	.ampdu_action = iwl_mvm_mac_ampdu_action,
 	.start = iwl_mvm_mac_start,
 	.reconfig_complete = iwl_mvm_mac_reconfig_complete,