Merge branch 'net-stmmac-Performance-improvements-in-Multi-Queue'

Jose Abreu says:

====================
net: stmmac: Performance improvements in Multi-Queue

Tested in XGMAC2 and GMAC5.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c

@@ -124,9 +124,9 @@ void dwmac4_disable_dma_irq(void __iomem *ioaddr, u32 chan)
 int dwmac4_dma_interrupt(void __iomem *ioaddr,
 			 struct stmmac_extra_stats *x, u32 chan)
 {
-	int ret = 0;
-
 	u32 intr_status = readl(ioaddr + DMA_CHAN_STATUS(chan));
+	u32 intr_en = readl(ioaddr + DMA_CHAN_INTR_ENA(chan));
+	int ret = 0;
 
 	/* ABNORMAL interrupts */
 	if (unlikely(intr_status & DMA_CHAN_STATUS_AIS)) {
@@ -151,16 +151,11 @@ int dwmac4_dma_interrupt(void __iomem *ioaddr,
 	if (likely(intr_status & DMA_CHAN_STATUS_NIS)) {
 		x->normal_irq_n++;
 		if (likely(intr_status & DMA_CHAN_STATUS_RI)) {
-			u32 value;
-
-			value = readl(ioaddr + DMA_CHAN_INTR_ENA(chan));
-			/* to schedule NAPI on real RIE event. */
-			if (likely(value & DMA_CHAN_INTR_ENA_RIE)) {
-				x->rx_normal_irq_n++;
-				ret |= handle_rx;
-			}
+			x->rx_normal_irq_n++;
+			ret |= handle_rx;
 		}
-		if (likely(intr_status & DMA_CHAN_STATUS_TI)) {
+		if (likely(intr_status & (DMA_CHAN_STATUS_TI |
+					  DMA_CHAN_STATUS_TBU))) {
 			x->tx_normal_irq_n++;
 			ret |= handle_tx;
 		}
@@ -168,12 +163,7 @@ int dwmac4_dma_interrupt(void __iomem *ioaddr,
 			x->rx_early_irq++;
 	}
 
-	/* Clear the interrupt by writing a logic 1 to the chanX interrupt
-	 * status [21-0] expect reserved bits [5-3]
-	 */
-	writel((intr_status & 0x3fffc7),
-	       ioaddr + DMA_CHAN_STATUS(chan));
-
+	writel(intr_status & intr_en, ioaddr + DMA_CHAN_STATUS(chan));
 	return ret;
 }
 

drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h

@@ -193,9 +193,10 @@
 #define XGMAC_AIE			BIT(14)
 #define XGMAC_RBUE			BIT(7)
 #define XGMAC_RIE			BIT(6)
+#define XGMAC_TBUE			BIT(2)
 #define XGMAC_TIE			BIT(0)
 #define XGMAC_DMA_INT_DEFAULT_EN	(XGMAC_NIE | XGMAC_AIE | XGMAC_RBUE | \
-					XGMAC_RIE | XGMAC_TIE)
+					XGMAC_RIE | XGMAC_TBUE | XGMAC_TIE)
 #define XGMAC_DMA_CH_Rx_WATCHDOG(x)	(0x0000313c + (0x80 * (x)))
 #define XGMAC_RWT			GENMASK(7, 0)
 #define XGMAC_DMA_CH_STATUS(x)		(0x00003160 + (0x80 * (x)))
@@ -204,6 +205,7 @@
 #define XGMAC_FBE			BIT(12)
 #define XGMAC_RBU			BIT(7)
 #define XGMAC_RI			BIT(6)
+#define XGMAC_TBU			BIT(2)
 #define XGMAC_TPS			BIT(1)
 #define XGMAC_TI			BIT(0)
 

drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c

@@ -283,12 +283,10 @@ static int dwxgmac2_dma_interrupt(void __iomem *ioaddr,
 		x->normal_irq_n++;
 
 		if (likely(intr_status & XGMAC_RI)) {
-			if (likely(intr_en & XGMAC_RIE)) {
-				x->rx_normal_irq_n++;
-				ret |= handle_rx;
-			}
+			x->rx_normal_irq_n++;
+			ret |= handle_rx;
 		}
-		if (likely(intr_status & XGMAC_TI)) {
+		if (likely(intr_status & (XGMAC_TI | XGMAC_TBU))) {
 			x->tx_normal_irq_n++;
 			ret |= handle_tx;
 		}

drivers/net/ethernet/stmicro/stmmac/stmmac.h

@@ -79,11 +79,10 @@ struct stmmac_rx_queue {
 };
 
 struct stmmac_channel {
-	struct napi_struct napi ____cacheline_aligned_in_smp;
+	struct napi_struct rx_napi ____cacheline_aligned_in_smp;
+	struct napi_struct tx_napi ____cacheline_aligned_in_smp;
 	struct stmmac_priv *priv_data;
 	u32 index;
-	int has_rx;
-	int has_tx;
 };
 
 struct stmmac_tc_entry {

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -155,7 +155,10 @@ static void stmmac_disable_all_queues(struct stmmac_priv *priv)
 	for (queue = 0; queue < maxq; queue++) {
 		struct stmmac_channel *ch = &priv->channel[queue];
 
-		napi_disable(&ch->napi);
+		if (queue < rx_queues_cnt)
+			napi_disable(&ch->rx_napi);
+		if (queue < tx_queues_cnt)
+			napi_disable(&ch->tx_napi);
 	}
 }
 
@@ -173,7 +176,10 @@ static void stmmac_enable_all_queues(struct stmmac_priv *priv)
 	for (queue = 0; queue < maxq; queue++) {
 		struct stmmac_channel *ch = &priv->channel[queue];
 
-		napi_enable(&ch->napi);
+		if (queue < rx_queues_cnt)
+			napi_enable(&ch->rx_napi);
+		if (queue < tx_queues_cnt)
+			napi_enable(&ch->tx_napi);
 	}
 }
 
@@ -1955,6 +1961,10 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue)
 		mod_timer(&priv->eee_ctrl_timer, STMMAC_LPI_T(eee_timer));
 	}
 
+	/* We still have pending packets, let's call for a new scheduling */
+	if (tx_q->dirty_tx != tx_q->cur_tx)
+		mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(10));
+
 	__netif_tx_unlock_bh(netdev_get_tx_queue(priv->dev, queue));
 
 	return count;
@@ -2045,23 +2055,15 @@ static int stmmac_napi_check(struct stmmac_priv *priv, u32 chan)
 	int status = stmmac_dma_interrupt_status(priv, priv->ioaddr,
 						 &priv->xstats, chan);
 	struct stmmac_channel *ch = &priv->channel[chan];
-	bool needs_work = false;
 
-	if ((status & handle_rx) && ch->has_rx) {
-		needs_work = true;
-	} else {
-		status &= ~handle_rx;
-	}
-
-	if ((status & handle_tx) && ch->has_tx) {
-		needs_work = true;
-	} else {
-		status &= ~handle_tx;
-	}
-
-	if (needs_work && napi_schedule_prep(&ch->napi)) {
+	if ((status & handle_rx) && (chan < priv->plat->rx_queues_to_use)) {
 		stmmac_disable_dma_irq(priv, priv->ioaddr, chan);
-		__napi_schedule(&ch->napi);
+		napi_schedule_irqoff(&ch->rx_napi);
+	}
+
+	if ((status & handle_tx) && (chan < priv->plat->tx_queues_to_use)) {
+		stmmac_disable_dma_irq(priv, priv->ioaddr, chan);
+		napi_schedule_irqoff(&ch->tx_napi);
 	}
 
 	return status;
@@ -2257,8 +2259,14 @@ static void stmmac_tx_timer(struct timer_list *t)
 
 	ch = &priv->channel[tx_q->queue_index];
 
-	if (likely(napi_schedule_prep(&ch->napi)))
-		__napi_schedule(&ch->napi);
+	/*
+	 * If NAPI is already running we can miss some events. Let's rearm
+	 * the timer and try again.
+	 */
+	if (likely(napi_schedule_prep(&ch->tx_napi)))
+		__napi_schedule(&ch->tx_napi);
+	else
+		mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(10));
 }
 
 /**
@@ -3514,7 +3522,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
 			else
 				skb->ip_summed = CHECKSUM_UNNECESSARY;
 
-			napi_gro_receive(&ch->napi, skb);
+			napi_gro_receive(&ch->rx_napi, skb);
 
 			priv->dev->stats.rx_packets++;
 			priv->dev->stats.rx_bytes += frame_len;
@@ -3529,40 +3537,45 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
 	return count;
 }
 
-/**
- *  stmmac_poll - stmmac poll method (NAPI)
- *  @napi : pointer to the napi structure.
- *  @budget : maximum number of packets that the current CPU can receive from
- *	      all interfaces.
- *  Description :
- *  To look at the incoming frames and clear the tx resources.
- */
-static int stmmac_napi_poll(struct napi_struct *napi, int budget)
+static int stmmac_napi_poll_rx(struct napi_struct *napi, int budget)
 {
 	struct stmmac_channel *ch =
-		container_of(napi, struct stmmac_channel, napi);
+		container_of(napi, struct stmmac_channel, rx_napi);
 	struct stmmac_priv *priv = ch->priv_data;
-	int work_done, rx_done = 0, tx_done = 0;
 	u32 chan = ch->index;
+	int work_done;
 
 	priv->xstats.napi_poll++;
 
-	if (ch->has_tx)
-		tx_done = stmmac_tx_clean(priv, budget, chan);
-	if (ch->has_rx)
-		rx_done = stmmac_rx(priv, budget, chan);
+	work_done = stmmac_rx(priv, budget, chan);
+	if (work_done < budget && napi_complete_done(napi, work_done))
+		stmmac_enable_dma_irq(priv, priv->ioaddr, chan);
+	return work_done;
+}
 
-	work_done = max(rx_done, tx_done);
+static int stmmac_napi_poll_tx(struct napi_struct *napi, int budget)
+{
+	struct stmmac_channel *ch =
+		container_of(napi, struct stmmac_channel, tx_napi);
+	struct stmmac_priv *priv = ch->priv_data;
+	struct stmmac_tx_queue *tx_q;
+	u32 chan = ch->index;
+	int work_done;
+
+	priv->xstats.napi_poll++;
+
+	work_done = stmmac_tx_clean(priv, DMA_TX_SIZE, chan);
 	work_done = min(work_done, budget);
 
-	if (work_done < budget && napi_complete_done(napi, work_done)) {
-		int stat;
-
+	if (work_done < budget && napi_complete_done(napi, work_done))
 		stmmac_enable_dma_irq(priv, priv->ioaddr, chan);
-		stat = stmmac_dma_interrupt_status(priv, priv->ioaddr,
-						   &priv->xstats, chan);
-		if (stat && napi_reschedule(napi))
-			stmmac_disable_dma_irq(priv, priv->ioaddr, chan);
+
+	/* Force transmission restart */
+	tx_q = &priv->tx_queue[chan];
+	if (tx_q->cur_tx != tx_q->dirty_tx) {
+		stmmac_enable_dma_transmission(priv, priv->ioaddr);
+		stmmac_set_tx_tail_ptr(priv, priv->ioaddr, tx_q->tx_tail_addr,
+				       chan);
 	}
 
 	return work_done;
@@ -4342,13 +4355,14 @@ int stmmac_dvr_probe(struct device *device,
 		ch->priv_data = priv;
 		ch->index = queue;
 
-		if (queue < priv->plat->rx_queues_to_use)
-			ch->has_rx = true;
-		if (queue < priv->plat->tx_queues_to_use)
-			ch->has_tx = true;
-
-		netif_napi_add(ndev, &ch->napi, stmmac_napi_poll,
-			       NAPI_POLL_WEIGHT);
+		if (queue < priv->plat->rx_queues_to_use) {
+			netif_napi_add(ndev, &ch->rx_napi, stmmac_napi_poll_rx,
+				       NAPI_POLL_WEIGHT);
+		}
+		if (queue < priv->plat->tx_queues_to_use) {
+			netif_napi_add(ndev, &ch->tx_napi, stmmac_napi_poll_tx,
+				       NAPI_POLL_WEIGHT);
+		}
 	}
 
 	mutex_init(&priv->lock);
@@ -4404,7 +4418,10 @@ int stmmac_dvr_probe(struct device *device,
 	for (queue = 0; queue < maxq; queue++) {
 		struct stmmac_channel *ch = &priv->channel[queue];
 
-		netif_napi_del(&ch->napi);
+		if (queue < priv->plat->rx_queues_to_use)
+			netif_napi_del(&ch->rx_napi);
+		if (queue < priv->plat->tx_queues_to_use)
+			netif_napi_del(&ch->tx_napi);
 	}
 error_hw_init:
 	destroy_workqueue(priv->wq);