net: 3c589_cs: convert to NAPI

Convert the 3c589_cs driver to NAPI to ease the interrupt workload.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

1 files changed, 88 insertions, 29 deletions

diff --git a/drivers/net/ethernet/3com/3c589_cs.c b/drivers/net/ethernet/3com/3c589_cs.c
index b9c7ec65aa84..75347796a903 100644
--- a/drivers/net/ethernet/3com/3c589_cs.c
+++ b/drivers/net/ethernet/3com/3c589_cs.c
@@ -137,6 +137,8 @@ struct el3_private {
 	u16			fast_poll;
 	unsigned long		last_irq;
 	spinlock_t		lock;
+	u16			pending;
+	struct napi_struct	napi;
 };
 
 static const char *if_names[] = { "auto", "10baseT", "10base2", "AUI" };
@@ -176,6 +178,7 @@ static void el3_tx_timeout(struct net_device *dev, unsigned int txqueue);
 static void set_rx_mode(struct net_device *dev);
 static void set_multicast_list(struct net_device *dev);
 static const struct ethtool_ops netdev_ethtool_ops;
+static int el3_napi_poll(struct napi_struct *napi, int budget);
 
 static void tc589_detach(struct pcmcia_device *p_dev);
 
@@ -219,6 +222,8 @@ static int tc589_probe(struct pcmcia_device *link)
 
 	dev->ethtool_ops = &netdev_ethtool_ops;
 
+	netif_napi_add(dev, &lp->napi, el3_napi_poll);
+
 	ret = tc589_config(link);
 	if (ret)
 		goto err_free_netdev;
@@ -527,6 +532,8 @@ static int el3_open(struct net_device *dev)
 	timer_setup(&lp->media, media_check, 0);
 	mod_timer(&lp->media, jiffies + HZ);
 
+	napi_enable(&lp->napi);
+
 	dev_dbg(&link->dev, "%s: opened, status %4.4x.\n",
 	  dev->name, inw(dev->base_addr + EL3_STATUS));
 
@@ -547,10 +554,10 @@ static void el3_tx_timeout(struct net_device *dev, unsigned int txqueue)
 	netif_wake_queue(dev);
 }
 
-static void pop_tx_status(struct net_device *dev)
+static int pop_tx_status(struct net_device *dev)
 {
 	unsigned int ioaddr = dev->base_addr;
-	int i;
+	int i, work = 0;
 
 	/* Clear the Tx status stack. */
 	for (i = 32; i > 0; i--) {
@@ -566,7 +573,9 @@ static void pop_tx_status(struct net_device *dev)
 			dev->stats.tx_aborted_errors++;
 		}
 		outb(0x00, ioaddr + TX_STATUS); /* Pop the status stack. */
+		work++;
 	}
+	return work;
 }
 
 static netdev_tx_t el3_start_xmit(struct sk_buff *skb,
@@ -606,47 +615,38 @@ static netdev_tx_t el3_start_xmit(struct sk_buff *skb,
 	return NETDEV_TX_OK;
 }
 
-/* The EL3 interrupt handler. */
-static irqreturn_t el3_interrupt(int irq, void *dev_id)
+static int el3_napi_handle(struct net_device *dev, int budget)
 {
-	struct net_device *dev = (struct net_device *) dev_id;
 	struct el3_private *lp = netdev_priv(dev);
-	unsigned int ioaddr;
+	unsigned int ioaddr = dev->base_addr;
 	__u16 status;
-	int i = 0, handled = 1;
-
-	if (!netif_device_present(dev))
-		return IRQ_NONE;
-
-	ioaddr = dev->base_addr;
-
-	netdev_dbg(dev, "interrupt, status %4.4x.\n", inw(ioaddr + EL3_STATUS));
+	int work = 0;
 
-	spin_lock(&lp->lock);
-	while ((status = inw(ioaddr + EL3_STATUS)) &
+	while ((status = (inw(ioaddr + EL3_STATUS) | lp->pending)) &
 	(IntLatch | RxComplete | StatsFull)) {
+		lp->pending = 0;
 		if ((status & 0xe000) != 0x2000) {
 			netdev_dbg(dev, "interrupt from dead card\n");
-			handled = 0;
-			break;
+			return 0;
 		}
 		if (status & RxComplete)
-			el3_rx(dev);
+			work += el3_rx(dev);
 		if (status & TxAvailable) {
 			netdev_dbg(dev, "    TX room bit was handled.\n");
 			/* There's room in the FIFO for a full-sized packet. */
 			outw(AckIntr | TxAvailable, ioaddr + EL3_CMD);
 			netif_wake_queue(dev);
+			work++;
 		}
 		if (status & TxComplete)
-			pop_tx_status(dev);
+			work += pop_tx_status(dev);
 		if (status & (AdapterFailure | RxEarly | StatsFull)) {
 			/* Handle all uncommon interrupts. */
 			if (status & StatsFull)		/* Empty statistics. */
 				update_stats(dev);
 			if (status & RxEarly) {
 				/* Rx early is unused. */
-				el3_rx(dev);
+				work += el3_rx(dev);
 				outw(AckIntr | RxEarly, ioaddr + EL3_CMD);
 			}
 			if (status & AdapterFailure) {
@@ -670,17 +670,74 @@ static irqreturn_t el3_interrupt(int irq, void *dev_id)
 				outw(AckIntr | AdapterFailure, ioaddr + EL3_CMD);
 			}
 		}
-		if (++i > 10) {
-			netdev_err(dev, "infinite loop in interrupt, status %4.4x.\n",
-					status);
-			/* Clear all interrupts */
-			outw(AckIntr | 0xFF, ioaddr + EL3_CMD);
-			break;
-		}
 		/* Acknowledge the IRQ. */
 		outw(AckIntr | IntReq | IntLatch, ioaddr + EL3_CMD);
 	}
 	lp->last_irq = jiffies;
+
+	return work;
+}
+
+static int el3_napi_poll(struct napi_struct *napi, int budget)
+{
+	struct net_device *dev = napi->dev;
+	struct el3_private *lp = netdev_priv(dev);
+	unsigned int ioaddr = dev->base_addr;
+	int work = 0;
+
+	if (!netif_running(dev)) {
+		napi_complete(napi);
+		return 0;
+	}
+
+	netdev_dbg(dev, "napi poll, status %4.4x.\n", inw(ioaddr + EL3_STATUS));
+
+	spin_lock(&lp->lock);
+	work = el3_napi_handle(dev, budget);
+	spin_unlock(&lp->lock);
+
+	netdev_dbg(dev, "exiting napi poll, status %4.4x.\n",
+			inw(ioaddr + EL3_STATUS));
+
+	budget -= work;
+	if (budget > 0) {
+		napi_complete(napi);
+		outw(SetIntrEnb | IntLatch | TxAvailable | RxComplete
+		 | StatsFull | AdapterFailure, ioaddr + EL3_CMD);
+	}
+
+	return work;
+}
+
+/* The EL3 interrupt handler. */
+static irqreturn_t el3_interrupt(int irq, void *dev_id)
+{
+	struct net_device *dev = (struct net_device *) dev_id;
+	struct el3_private *lp = netdev_priv(dev);
+	unsigned int ioaddr;
+	__u16 status;
+	int handled = 1;
+
+	if (!netif_device_present(dev))
+		return IRQ_NONE;
+
+	ioaddr = dev->base_addr;
+
+	netdev_dbg(dev, "interrupt, status %4.4x.\n", inw(ioaddr + EL3_STATUS));
+
+	spin_lock(&lp->lock);
+	status = inw(ioaddr + EL3_STATUS);
+	if ((status & 0xe000) != 0x2000) {
+		netdev_dbg(dev, "interrupt from dead card\n");
+		handled = 0;
+	} else {
+		lp->pending |= status;
+		outw(SetIntrEnb, ioaddr + EL3_CMD);
+		status &= IntLatch | TxAvailable | RxComplete
+		 | StatsFull | AdapterFailure;
+		outw(AckIntr | status, ioaddr + EL3_CMD);
+		napi_schedule(&lp->napi);
+	}
 	spin_unlock(&lp->lock);
 	netdev_dbg(dev, "exiting interrupt, status %4.4x.\n",
 			inw(ioaddr + EL3_STATUS));
@@ -893,7 +950,7 @@ static int el3_rx(struct net_device *dev)
 	}
 	if (worklimit == 0)
 		netdev_warn(dev, "too much work in el3_rx!\n");
-	return 0;
+	return 32 - worklimit;
 }
 
 static void set_rx_mode(struct net_device *dev)
@@ -953,6 +1010,8 @@ static int el3_close(struct net_device *dev)
 			update_stats(dev);
 	}
 
+	napi_disable(&lp->napi);
+
 	link->open--;
 	netif_stop_queue(dev);
 	del_timer_sync(&lp->media);