mt76: convert from tx tasklet to tx worker thread

This improves performance by allowing the scheduler to move the tx scheduling
work to idle CPUs. Since tx scheduling work is very latency sensitive and
kept short via AQL, sched_set_fifo_low is used to keep worker priority above
normal tasks
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/dma.c

@@ -592,6 +592,7 @@ void mt76_dma_cleanup(struct mt76_dev *dev)
 {
 	int i;
 
+	mt76_worker_disable(&dev->tx_worker);
 	netif_napi_del(&dev->tx_napi);
 	for (i = 0; i < ARRAY_SIZE(dev->q_tx); i++)
 		mt76_dma_tx_cleanup(dev, i, true);

drivers/net/wireless/mediatek/mt76/mac80211.c

@@ -2,6 +2,7 @@
 /*
  * Copyright (C) 2016 Felix Fietkau <nbd@nbd.name>
  */
+#include <linux/sched.h>
 #include <linux/of.h>
 #include "mt76.h"
 
@@ -436,14 +437,13 @@ mt76_alloc_device(struct device *pdev, unsigned int size,
 	skb_queue_head_init(&dev->mcu.res_q);
 	init_waitqueue_head(&dev->mcu.wait);
 	mutex_init(&dev->mcu.mutex);
+	dev->tx_worker.fn = mt76_tx_worker;
 
 	INIT_LIST_HEAD(&dev->txwi_cache);
 
 	for (i = 0; i < ARRAY_SIZE(dev->q_rx); i++)
 		skb_queue_head_init(&dev->rx_skb[i]);
 
-	tasklet_init(&dev->tx_tasklet, mt76_tx_tasklet, (unsigned long)dev);
-
 	dev->wq = alloc_ordered_workqueue("mt76", 0);
 	if (!dev->wq) {
 		ieee80211_free_hw(hw);
@@ -486,7 +486,14 @@ int mt76_register_device(struct mt76_dev *dev, bool vht,
 			return ret;
 	}
 
-	return ieee80211_register_hw(hw);
+	ret = ieee80211_register_hw(hw);
+	if (ret)
+		return ret;
+
+	WARN_ON(mt76_worker_setup(hw, &dev->tx_worker, NULL, "tx"));
+	sched_set_fifo_low(dev->tx_worker.task);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(mt76_register_device);
 
@@ -503,6 +510,7 @@ EXPORT_SYMBOL_GPL(mt76_unregister_device);
 
 void mt76_free_device(struct mt76_dev *dev)
 {
+	mt76_worker_teardown(&dev->tx_worker);
 	if (dev->wq) {
 		destroy_workqueue(dev->wq);
 		dev->wq = NULL;

drivers/net/wireless/mediatek/mt76/mt76.h

@@ -604,7 +604,7 @@ struct mt76_dev {
 	const struct mt76_queue_ops *queue_ops;
 	int tx_dma_idx[4];
 
-	struct tasklet_struct tx_tasklet;
+	struct mt76_worker tx_worker;
 	struct napi_struct tx_napi;
 	struct delayed_work mac_work;
 
@@ -906,7 +906,7 @@ void mt76_stop_tx_queues(struct mt76_dev *dev, struct ieee80211_sta *sta,
 void mt76_tx_check_agg_ssn(struct ieee80211_sta *sta, struct sk_buff *skb);
 void mt76_txq_schedule(struct mt76_phy *phy, enum mt76_txq_id qid);
 void mt76_txq_schedule_all(struct mt76_phy *phy);
-void mt76_tx_tasklet(unsigned long data);
+void mt76_tx_worker(struct mt76_worker *w);
 void mt76_release_buffered_frames(struct ieee80211_hw *hw,
 				  struct ieee80211_sta *sta,
 				  u16 tids, int nframes,

drivers/net/wireless/mediatek/mt76/mt7603/dma.c

@@ -163,7 +163,7 @@ static int mt7603_poll_tx(struct napi_struct *napi, int budget)
 
 	mt7603_mac_sta_poll(dev);
 
-	tasklet_schedule(&dev->mt76.tx_tasklet);
+	mt76_worker_schedule(&dev->mt76.tx_worker);
 
 	return 0;
 }
@@ -246,6 +246,5 @@ void mt7603_dma_cleanup(struct mt7603_dev *dev)
 		   MT_WPDMA_GLO_CFG_RX_DMA_EN |
 		   MT_WPDMA_GLO_CFG_TX_WRITEBACK_DONE);
 
-	tasklet_kill(&dev->mt76.tx_tasklet);
 	mt76_dma_cleanup(&dev->mt76);
 }

drivers/net/wireless/mediatek/mt76/mt7603/mac.c

@@ -1402,7 +1402,7 @@ static void mt7603_mac_watchdog_reset(struct mt7603_dev *dev)
 	/* lock/unlock all queues to ensure that no tx is pending */
 	mt76_txq_schedule_all(&dev->mphy);
 
-	tasklet_disable(&dev->mt76.tx_tasklet);
+	mt76_worker_disable(&dev->mt76.tx_worker);
 	tasklet_disable(&dev->mt76.pre_tbtt_tasklet);
 	napi_disable(&dev->mt76.napi[0]);
 	napi_disable(&dev->mt76.napi[1]);
@@ -1451,7 +1451,7 @@ static void mt7603_mac_watchdog_reset(struct mt7603_dev *dev)
 	clear_bit(MT76_RESET, &dev->mphy.state);
 	mutex_unlock(&dev->mt76.mutex);
 
-	tasklet_enable(&dev->mt76.tx_tasklet);
+	mt76_worker_enable(&dev->mt76.tx_worker);
 	napi_enable(&dev->mt76.tx_napi);
 	napi_schedule(&dev->mt76.tx_napi);
 

drivers/net/wireless/mediatek/mt76/mt7615/dma.c

@@ -297,6 +297,5 @@ void mt7615_dma_cleanup(struct mt7615_dev *dev)
 		   MT_WPDMA_GLO_CFG_RX_DMA_EN);
 	mt76_set(dev, MT_WPDMA_GLO_CFG, MT_WPDMA_GLO_CFG_SW_RESET);
 
-	tasklet_kill(&dev->mt76.tx_tasklet);
 	mt76_dma_cleanup(&dev->mt76);
 }

drivers/net/wireless/mediatek/mt76/mt7615/mac.c

@@ -1462,7 +1462,7 @@ static void mt7615_mac_tx_free(struct mt7615_dev *dev, struct sk_buff *skb)
 	rcu_read_unlock();
 
 	mt7615_pm_power_save_sched(dev);
-	tasklet_schedule(&dev->mt76.tx_tasklet);
+	mt76_worker_schedule(&dev->mt76.tx_worker);
 }
 
 void mt7615_queue_rx_skb(struct mt76_dev *mdev, enum mt76_rxq_id q,
@@ -1888,7 +1888,7 @@ void mt7615_pm_wake_work(struct work_struct *work)
 	}
 	spin_unlock_bh(&dev->pm.txq_lock);
 
-	tasklet_schedule(&dev->mt76.tx_tasklet);
+	mt76_worker_schedule(&dev->mt76.tx_worker);
 
 out:
 	ieee80211_wake_queues(mphy->hw);
@@ -2130,7 +2130,7 @@ void mt7615_mac_reset_work(struct work_struct *work)
 	if (ext_phy)
 		mt76_txq_schedule_all(ext_phy);
 
-	tasklet_disable(&dev->mt76.tx_tasklet);
+	mt76_worker_disable(&dev->mt76.tx_worker);
 	napi_disable(&dev->mt76.napi[0]);
 	napi_disable(&dev->mt76.napi[1]);
 	napi_disable(&dev->mt76.tx_napi);
@@ -2151,7 +2151,7 @@ void mt7615_mac_reset_work(struct work_struct *work)
 	clear_bit(MT76_MCU_RESET, &dev->mphy.state);
 	clear_bit(MT76_RESET, &dev->mphy.state);
 
-	tasklet_enable(&dev->mt76.tx_tasklet);
+	mt76_worker_enable(&dev->mt76.tx_worker);
 	napi_enable(&dev->mt76.tx_napi);
 	napi_schedule(&dev->mt76.tx_napi);
 

drivers/net/wireless/mediatek/mt76/mt7615/main.c

@@ -707,7 +707,7 @@ mt7615_wake_tx_queue(struct ieee80211_hw *hw, struct ieee80211_txq *txq)
 	}
 
 	dev->pm.last_activity = jiffies;
-	tasklet_schedule(&dev->mt76.tx_tasklet);
+	mt76_worker_schedule(&dev->mt76.tx_worker);
 }
 
 static void mt7615_tx(struct ieee80211_hw *hw,

drivers/net/wireless/mediatek/mt76/mt7615/pci.c

@@ -88,7 +88,7 @@ static int mt7615_pci_suspend(struct pci_dev *pdev, pm_message_t state)
 	}
 
 	napi_disable(&mdev->tx_napi);
-	tasklet_kill(&mdev->tx_tasklet);
+	mt76_worker_disable(&mdev->tx_worker);
 
 	mt76_for_each_q_rx(mdev, i) {
 		napi_disable(&mdev->napi[i]);
@@ -162,6 +162,7 @@ static int mt7615_pci_resume(struct pci_dev *pdev)
 	if (pdma_reset)
 		dev_err(mdev->dev, "PDMA engine must be reinitialized\n");
 
+	mt76_worker_enable(&mdev->tx_worker);
 	mt76_for_each_q_rx(mdev, i) {
 		napi_enable(&mdev->napi[i]);
 		napi_schedule(&mdev->napi[i]);

drivers/net/wireless/mediatek/mt76/mt7615/usb.c

@@ -180,9 +180,7 @@ static int mt7663u_suspend(struct usb_interface *intf, pm_message_t state)
 	}
 
 	mt76u_stop_rx(&dev->mt76);
-
 	mt76u_stop_tx(&dev->mt76);
-	tasklet_kill(&dev->mt76.tx_tasklet);
 
 	return 0;
 }

drivers/net/wireless/mediatek/mt76/mt76x0/pci.c

@@ -204,7 +204,7 @@ static void mt76x0e_cleanup(struct mt76x02_dev *dev)
 	tasklet_disable(&dev->mt76.pre_tbtt_tasklet);
 	mt76x0_chip_onoff(dev, false, false);
 	mt76x0e_stop_hw(dev);
-	mt76x02_dma_cleanup(dev);
+	mt76_dma_cleanup(&dev->mt76);
 	mt76x02_mcu_cleanup(dev);
 }
 

drivers/net/wireless/mediatek/mt76/mt76x02_dma.h

@@ -61,6 +61,5 @@ mt76x02_wait_for_wpdma(struct mt76_dev *dev, int timeout)
 
 int mt76x02_dma_init(struct mt76x02_dev *dev);
 void mt76x02_dma_disable(struct mt76x02_dev *dev);
-void mt76x02_dma_cleanup(struct mt76x02_dev *dev);
 
 #endif /* __MT76x02_DMA_H */

drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c

@@ -149,9 +149,11 @@ static void mt76x02_process_tx_status_fifo(struct mt76x02_dev *dev)
 		mt76x02_send_tx_status(dev, &stat, &update);
 }
 
-static void mt76x02_tx_tasklet(unsigned long data)
+static void mt76x02_tx_worker(struct mt76_worker *w)
 {
-	struct mt76x02_dev *dev = (struct mt76x02_dev *)data;
+	struct mt76x02_dev *dev;
+
+	dev = container_of(w, struct mt76x02_dev, mt76.tx_worker);
 
 	mt76x02_mac_poll_tx_status(dev, false);
 	mt76x02_process_tx_status_fifo(dev);
@@ -176,7 +178,7 @@ static int mt76x02_poll_tx(struct napi_struct *napi, int budget)
 	for (i = MT_TXQ_MCU; i >= 0; i--)
 		mt76_queue_tx_cleanup(dev, i, false);
 
-	tasklet_schedule(&dev->mt76.tx_tasklet);
+	mt76_worker_schedule(&dev->mt76.tx_worker);
 
 	return 0;
 }
@@ -195,8 +197,7 @@ int mt76x02_dma_init(struct mt76x02_dev *dev)
 	if (!status_fifo)
 		return -ENOMEM;
 
-	tasklet_init(&dev->mt76.tx_tasklet, mt76x02_tx_tasklet,
-		     (unsigned long)dev);
+	dev->mt76.tx_worker.fn = mt76x02_tx_worker;
 	tasklet_init(&dev->mt76.pre_tbtt_tasklet, mt76x02_pre_tbtt_tasklet,
 		     (unsigned long)dev);
 
@@ -323,13 +324,6 @@ static void mt76x02_dma_enable(struct mt76x02_dev *dev)
 		   MT_WPDMA_GLO_CFG_TX_WRITEBACK_DONE);
 }
 
-void mt76x02_dma_cleanup(struct mt76x02_dev *dev)
-{
-	tasklet_kill(&dev->mt76.tx_tasklet);
-	mt76_dma_cleanup(&dev->mt76);
-}
-EXPORT_SYMBOL_GPL(mt76x02_dma_cleanup);
-
 void mt76x02_dma_disable(struct mt76x02_dev *dev)
 {
 	u32 val = mt76_rr(dev, MT_WPDMA_GLO_CFG);
@@ -447,7 +441,7 @@ static void mt76x02_watchdog_reset(struct mt76x02_dev *dev)
 	set_bit(MT76_RESET, &dev->mphy.state);
 
 	tasklet_disable(&dev->mt76.pre_tbtt_tasklet);
-	tasklet_disable(&dev->mt76.tx_tasklet);
+	mt76_worker_disable(&dev->mt76.tx_worker);
 	napi_disable(&dev->mt76.tx_napi);
 
 	mt76_for_each_q_rx(&dev->mt76, i) {
@@ -504,7 +498,7 @@ static void mt76x02_watchdog_reset(struct mt76x02_dev *dev)
 
 	clear_bit(MT76_RESET, &dev->mphy.state);
 
-	tasklet_enable(&dev->mt76.tx_tasklet);
+	mt76_worker_enable(&dev->mt76.tx_worker);
 	napi_enable(&dev->mt76.tx_napi);
 	napi_schedule(&dev->mt76.tx_napi);
 

drivers/net/wireless/mediatek/mt76/mt76x2/pci.c

@@ -113,7 +113,7 @@ mt76x2e_suspend(struct pci_dev *pdev, pm_message_t state)
 
 	napi_disable(&mdev->tx_napi);
 	tasklet_kill(&mdev->pre_tbtt_tasklet);
-	tasklet_kill(&mdev->tx_tasklet);
+	mt76_worker_disable(&mdev->tx_worker);
 
 	mt76_for_each_q_rx(mdev, i)
 		napi_disable(&mdev->napi[i]);
@@ -147,6 +147,7 @@ mt76x2e_resume(struct pci_dev *pdev)
 
 	pci_restore_state(pdev);
 
+	mt76_worker_enable(&mdev->tx_worker);
 	mt76_for_each_q_rx(mdev, i) {
 		napi_enable(&mdev->napi[i]);
 		napi_schedule(&mdev->napi[i]);

drivers/net/wireless/mediatek/mt76/mt76x2/pci_init.c

@@ -283,7 +283,7 @@ void mt76x2_cleanup(struct mt76x02_dev *dev)
 	tasklet_disable(&dev->dfs_pd.dfs_tasklet);
 	tasklet_disable(&dev->mt76.pre_tbtt_tasklet);
 	mt76x2_stop_hardware(dev);
-	mt76x02_dma_cleanup(dev);
+	mt76_dma_cleanup(&dev->mt76);
 	mt76x02_mcu_cleanup(dev);
 }
 

drivers/net/wireless/mediatek/mt76/mt7915/dma.c

@@ -372,6 +372,5 @@ void mt7915_dma_cleanup(struct mt7915_dev *dev)
 		 MT_WFDMA0_RST_DMASHDL_ALL_RST |
 		 MT_WFDMA0_RST_LOGIC_RST);
 
-	tasklet_kill(&dev->mt76.tx_tasklet);
 	mt76_dma_cleanup(&dev->mt76);
 }

drivers/net/wireless/mediatek/mt76/mt7915/mac.c

@@ -951,7 +951,7 @@ void mt7915_mac_tx_free(struct mt7915_dev *dev, struct sk_buff *skb)
 	dev_kfree_skb(skb);
 
 	mt7915_mac_sta_poll(dev);
-	tasklet_schedule(&dev->mt76.tx_tasklet);
+	mt76_worker_schedule(&dev->mt76.tx_worker);
 }
 
 void mt7915_tx_complete_skb(struct mt76_dev *mdev, struct mt76_queue_entry *e)
@@ -1223,7 +1223,7 @@ void mt7915_mac_reset_work(struct work_struct *work)
 	if (ext_phy)
 		mt76_txq_schedule_all(ext_phy);
 
-	tasklet_disable(&dev->mt76.tx_tasklet);
+	mt76_worker_disable(&dev->mt76.tx_worker);
 	napi_disable(&dev->mt76.napi[0]);
 	napi_disable(&dev->mt76.napi[1]);
 	napi_disable(&dev->mt76.napi[2]);
@@ -1243,7 +1243,7 @@ void mt7915_mac_reset_work(struct work_struct *work)
 	clear_bit(MT76_MCU_RESET, &dev->mphy.state);
 	clear_bit(MT76_RESET, &dev->mphy.state);
 
-	tasklet_enable(&dev->mt76.tx_tasklet);
+	mt76_worker_enable(&dev->mt76.tx_worker);
 	napi_enable(&dev->mt76.tx_napi);
 	napi_schedule(&dev->mt76.tx_napi);
 

drivers/net/wireless/mediatek/mt76/testmode.c

@@ -161,7 +161,7 @@ mt76_testmode_tx_start(struct mt76_dev *dev)
 	td->tx_queued = 0;
 	td->tx_done = 0;
 	td->tx_pending = td->tx_count;
-	tasklet_schedule(&dev->tx_tasklet);
+	mt76_worker_schedule(&dev->tx_worker);
 }
 
 static void
@@ -169,11 +169,11 @@ mt76_testmode_tx_stop(struct mt76_dev *dev)
 {
 	struct mt76_testmode_data *td = &dev->test;
 
-	tasklet_disable(&dev->tx_tasklet);
+	mt76_worker_disable(&dev->tx_worker);
 
 	td->tx_pending = 0;
 
-	tasklet_enable(&dev->tx_tasklet);
+	mt76_worker_enable(&dev->tx_worker);
 
 	wait_event_timeout(dev->tx_wait, td->tx_done == td->tx_queued, 10 * HZ);
 

drivers/net/wireless/mediatek/mt76/tx.c

@@ -604,9 +604,9 @@ void mt76_txq_schedule_all(struct mt76_phy *phy)
 }
 EXPORT_SYMBOL_GPL(mt76_txq_schedule_all);
 
-void mt76_tx_tasklet(unsigned long data)
+void mt76_tx_worker(struct mt76_worker *w)
 {
-	struct mt76_dev *dev = (struct mt76_dev *)data;
+	struct mt76_dev *dev = container_of(w, struct mt76_dev, tx_worker);
 
 	mt76_txq_schedule_all(&dev->phy);
 	if (dev->phy2)
@@ -649,7 +649,7 @@ void mt76_wake_tx_queue(struct ieee80211_hw *hw, struct ieee80211_txq *txq)
 	if (!test_bit(MT76_STATE_RUNNING, &phy->state))
 		return;
 
-	tasklet_schedule(&dev->tx_tasklet);
+	mt76_worker_schedule(&dev->tx_worker);
 }
 EXPORT_SYMBOL_GPL(mt76_wake_tx_queue);
 

drivers/net/wireless/mediatek/mt76/usb.c

@@ -792,9 +792,9 @@ int mt76u_resume_rx(struct mt76_dev *dev)
 }
 EXPORT_SYMBOL_GPL(mt76u_resume_rx);
 
-static void mt76u_tx_tasklet(unsigned long data)
+static void mt76u_tx_worker(struct mt76_worker *w)
 {
-	struct mt76_dev *dev = (struct mt76_dev *)data;
+	struct mt76_dev *dev = container_of(w, struct mt76_dev, tx_worker);
 	struct mt76_queue_entry entry;
 	struct mt76_queue *q;
 	bool wake;
@@ -864,7 +864,7 @@ static void mt76u_complete_tx(struct urb *urb)
 		dev_err(dev->dev, "tx urb failed: %d\n", urb->status);
 	e->done = true;
 
-	tasklet_schedule(&dev->tx_tasklet);
+	mt76_worker_schedule(&dev->tx_worker);
 }
 
 static int
@@ -1020,6 +1020,8 @@ void mt76u_stop_tx(struct mt76_dev *dev)
 {
 	int ret;
 
+	mt76_worker_disable(&dev->tx_worker);
+
 	ret = wait_event_timeout(dev->tx_wait, !mt76_has_tx_pending(&dev->phy),
 				 HZ / 5);
 	if (!ret) {
@@ -1038,8 +1040,6 @@ void mt76u_stop_tx(struct mt76_dev *dev)
 				usb_kill_urb(q->entry[j].urb);
 		}
 
-		tasklet_kill(&dev->tx_tasklet);
-
 		/* On device removal we maight queue skb's, but mt76u_tx_kick()
 		 * will fail to submit urb, cleanup those skb's manually.
 		 */
@@ -1058,6 +1058,8 @@ void mt76u_stop_tx(struct mt76_dev *dev)
 	cancel_work_sync(&dev->usb.stat_work);
 	clear_bit(MT76_READING_STATS, &dev->phy.state);
 
+	mt76_worker_enable(&dev->tx_worker);
+
 	mt76_tx_status_check(dev, NULL, true);
 }
 EXPORT_SYMBOL_GPL(mt76u_stop_tx);
@@ -1107,8 +1109,8 @@ int mt76u_init(struct mt76_dev *dev,
 	mt76u_ops.rmw = ext ? mt76u_rmw_ext : mt76u_rmw;
 	mt76u_ops.write_copy = ext ? mt76u_copy_ext : mt76u_copy;
 
+	dev->tx_worker.fn = mt76u_tx_worker;
 	tasklet_init(&usb->rx_tasklet, mt76u_rx_tasklet, (unsigned long)dev);
-	tasklet_init(&dev->tx_tasklet, mt76u_tx_tasklet, (unsigned long)dev);
 	INIT_WORK(&usb->stat_work, mt76u_tx_status_data);
 
 	usb->data_len = usb_maxpacket(udev, usb_sndctrlpipe(udev, 0), 1);