[NET]: Make NAPI polling independent of struct net_device objects.

Several devices have multiple independant RX queues per net
device, and some have a single interrupt doorbell for several
queues.

In either case, it's easier to support layouts like that if the
structure representing the poll is independant from the net
device itself.

The signature of the ->poll() call back goes from:

	int foo_poll(struct net_device *dev, int *budget)

to

	int foo_poll(struct napi_struct *napi, int budget)

The caller is returned the number of RX packets processed (or
the number of "NAPI credits" consumed if you want to get
abstract).  The callee no longer messes around bumping
dev->quota, *budget, etc. because that is all handled in the
caller upon return.

The napi_struct is to be embedded in the device driver private data
structures.

Furthermore, it is the driver's responsibility to disable all NAPI
instances in it's ->stop() device close handler.  Since the
napi_struct is privatized into the driver's private data structures,
only the driver knows how to get at all of the napi_struct instances
it may have per-device.

With lots of help and suggestions from Rusty Russell, Roland Dreier,
Michael Chan, Jeff Garzik, and Jamal Hadi Salim.

Bug fixes from Thomas Graf, Roland Dreier, Peter Zijlstra,
Joseph Fannin, Scott Wood, Hans J. Koch, and Michael Chan.

[ Ported to current tree and all drivers converted.  Integrated
  Stephen's follow-on kerneldoc additions, and restored poll_list
  handling to the old style to fix mutual exclusion issues.  -DaveM ]

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 38 insertions, 31 deletions

diff --git a/drivers/net/forcedeth.c b/drivers/net/forcedeth.c
index 1938d6dfc863..24c1294614f2 100644
--- a/drivers/net/forcedeth.c
+++ b/drivers/net/forcedeth.c
@@ -159,6 +159,8 @@
 #define dprintk(x...)		do { } while (0)
 #endif
 
+#define TX_WORK_PER_LOOP  64
+#define RX_WORK_PER_LOOP  64
 
 /*
  * Hardware access:
@@ -745,6 +747,9 @@ struct nv_skb_map {
 struct fe_priv {
 	spinlock_t lock;
 
+	struct net_device *dev;
+	struct napi_struct napi;
+
 	/* General data:
 	 * Locking: spin_lock(&np->lock); */
 	struct net_device_stats stats;
@@ -1586,9 +1591,10 @@ static int nv_alloc_rx_optimized(struct net_device *dev)
 static void nv_do_rx_refill(unsigned long data)
 {
 	struct net_device *dev = (struct net_device *) data;
+	struct fe_priv *np = netdev_priv(dev);
 
 	/* Just reschedule NAPI rx processing */
-	netif_rx_schedule(dev);
+	netif_rx_schedule(dev, &np->napi);
 }
 #else
 static void nv_do_rx_refill(unsigned long data)
@@ -2997,7 +3003,7 @@ static irqreturn_t nv_nic_irq(int foo, void *data)
 
 #ifdef CONFIG_FORCEDETH_NAPI
 		if (events & NVREG_IRQ_RX_ALL) {
-			netif_rx_schedule(dev);
+			netif_rx_schedule(dev, &np->napi);
 
 			/* Disable furthur receive irq's */
 			spin_lock(&np->lock);
@@ -3010,7 +3016,7 @@ static irqreturn_t nv_nic_irq(int foo, void *data)
 			spin_unlock(&np->lock);
 		}
 #else
-		if (nv_rx_process(dev, dev->weight)) {
+		if (nv_rx_process(dev, RX_WORK_PER_LOOP)) {
 			if (unlikely(nv_alloc_rx(dev))) {
 				spin_lock(&np->lock);
 				if (!np->in_shutdown)
@@ -3079,8 +3085,6 @@ static irqreturn_t nv_nic_irq(int foo, void *data)
 	return IRQ_RETVAL(i);
 }
 
-#define TX_WORK_PER_LOOP  64
-#define RX_WORK_PER_LOOP  64
 /**
  * All _optimized functions are used to help increase performance
  * (reduce CPU and increase throughput). They use descripter version 3,
@@ -3114,7 +3118,7 @@ static irqreturn_t nv_nic_irq_optimized(int foo, void *data)
 
 #ifdef CONFIG_FORCEDETH_NAPI
 		if (events & NVREG_IRQ_RX_ALL) {
-			netif_rx_schedule(dev);
+			netif_rx_schedule(dev, &np->napi);
 
 			/* Disable furthur receive irq's */
 			spin_lock(&np->lock);
@@ -3127,7 +3131,7 @@ static irqreturn_t nv_nic_irq_optimized(int foo, void *data)
 			spin_unlock(&np->lock);
 		}
 #else
-		if (nv_rx_process_optimized(dev, dev->weight)) {
+		if (nv_rx_process_optimized(dev, RX_WORK_PER_LOOP)) {
 			if (unlikely(nv_alloc_rx_optimized(dev))) {
 				spin_lock(&np->lock);
 				if (!np->in_shutdown)
@@ -3245,19 +3249,19 @@ static irqreturn_t nv_nic_irq_tx(int foo, void *data)
 }
 
 #ifdef CONFIG_FORCEDETH_NAPI
-static int nv_napi_poll(struct net_device *dev, int *budget)
+static int nv_napi_poll(struct napi_struct *napi, int budget)
 {
-	int pkts, limit = min(*budget, dev->quota);
-	struct fe_priv *np = netdev_priv(dev);
+	struct fe_priv *np = container_of(napi, struct fe_priv, napi);
+	struct net_device *dev = np->dev;
 	u8 __iomem *base = get_hwbase(dev);
 	unsigned long flags;
-	int retcode;
+	int pkts, retcode;
 
 	if (np->desc_ver == DESC_VER_1 || np->desc_ver == DESC_VER_2) {
-		pkts = nv_rx_process(dev, limit);
+		pkts = nv_rx_process(dev, budget);
 		retcode = nv_alloc_rx(dev);
 	} else {
-		pkts = nv_rx_process_optimized(dev, limit);
+		pkts = nv_rx_process_optimized(dev, budget);
 		retcode = nv_alloc_rx_optimized(dev);
 	}
 
@@ -3268,13 +3272,12 @@ static int nv_napi_poll(struct net_device *dev, int *budget)
 		spin_unlock_irqrestore(&np->lock, flags);
 	}
 
-	if (pkts < limit) {
-		/* all done, no more packets present */
-		netif_rx_complete(dev);
-
+	if (pkts < budget) {
 		/* re-enable receive interrupts */
 		spin_lock_irqsave(&np->lock, flags);
 
+		__netif_rx_complete(dev, napi);
+
 		np->irqmask |= NVREG_IRQ_RX_ALL;
 		if (np->msi_flags & NV_MSI_X_ENABLED)
 			writel(NVREG_IRQ_RX_ALL, base + NvRegIrqMask);
@@ -3282,13 +3285,8 @@ static int nv_napi_poll(struct net_device *dev, int *budget)
 			writel(np->irqmask, base + NvRegIrqMask);
 
 		spin_unlock_irqrestore(&np->lock, flags);
-		return 0;
-	} else {
-		/* used up our quantum, so reschedule */
-		dev->quota -= pkts;
-		*budget -= pkts;
-		return 1;
 	}
+	return pkts;
 }
 #endif
 
@@ -3296,6 +3294,7 @@ static int nv_napi_poll(struct net_device *dev, int *budget)
 static irqreturn_t nv_nic_irq_rx(int foo, void *data)
 {
 	struct net_device *dev = (struct net_device *) data;
+	struct fe_priv *np = netdev_priv(dev);
 	u8 __iomem *base = get_hwbase(dev);
 	u32 events;
 
@@ -3303,7 +3302,7 @@ static irqreturn_t nv_nic_irq_rx(int foo, void *data)
 	writel(NVREG_IRQ_RX_ALL, base + NvRegMSIXIrqStatus);
 
 	if (events) {
-		netif_rx_schedule(dev);
+		netif_rx_schedule(dev, &np->napi);
 		/* disable receive interrupts on the nic */
 		writel(NVREG_IRQ_RX_ALL, base + NvRegIrqMask);
 		pci_push(base);
@@ -3329,7 +3328,7 @@ static irqreturn_t nv_nic_irq_rx(int foo, void *data)
 		if (!(events & np->irqmask))
 			break;
 
-		if (nv_rx_process_optimized(dev, dev->weight)) {
+		if (nv_rx_process_optimized(dev, RX_WORK_PER_LOOP)) {
 			if (unlikely(nv_alloc_rx_optimized(dev))) {
 				spin_lock_irqsave(&np->lock, flags);
 				if (!np->in_shutdown)
@@ -4620,7 +4619,9 @@ static void nv_self_test(struct net_device *dev, struct ethtool_test *test, u64
 	if (test->flags & ETH_TEST_FL_OFFLINE) {
 		if (netif_running(dev)) {
 			netif_stop_queue(dev);
-			netif_poll_disable(dev);
+#ifdef CONFIG_FORCEDETH_NAPI
+			napi_disable(&np->napi);
+#endif
 			netif_tx_lock_bh(dev);
 			spin_lock_irq(&np->lock);
 			nv_disable_hw_interrupts(dev, np->irqmask);
@@ -4679,7 +4680,9 @@ static void nv_self_test(struct net_device *dev, struct ethtool_test *test, u64
 			nv_start_rx(dev);
 			nv_start_tx(dev);
 			netif_start_queue(dev);
-			netif_poll_enable(dev);
+#ifdef CONFIG_FORCEDETH_NAPI
+			napi_enable(&np->napi);
+#endif
 			nv_enable_hw_interrupts(dev, np->irqmask);
 		}
 	}
@@ -4911,7 +4914,9 @@ static int nv_open(struct net_device *dev)
 	nv_start_rx(dev);
 	nv_start_tx(dev);
 	netif_start_queue(dev);
-	netif_poll_enable(dev);
+#ifdef CONFIG_FORCEDETH_NAPI
+	napi_enable(&np->napi);
+#endif
 
 	if (ret) {
 		netif_carrier_on(dev);
@@ -4942,7 +4947,9 @@ static int nv_close(struct net_device *dev)
 	spin_lock_irq(&np->lock);
 	np->in_shutdown = 1;
 	spin_unlock_irq(&np->lock);
-	netif_poll_disable(dev);
+#ifdef CONFIG_FORCEDETH_NAPI
+	napi_disable(&np->napi);
+#endif
 	synchronize_irq(dev->irq);
 
 	del_timer_sync(&np->oom_kick);
@@ -4994,6 +5001,7 @@ static int __devinit nv_probe(struct pci_dev *pci_dev, const struct pci_device_i
 		goto out;
 
 	np = netdev_priv(dev);
+	np->dev = dev;
 	np->pci_dev = pci_dev;
 	spin_lock_init(&np->lock);
 	SET_MODULE_OWNER(dev);
@@ -5155,9 +5163,8 @@ static int __devinit nv_probe(struct pci_dev *pci_dev, const struct pci_device_i
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	dev->poll_controller = nv_poll_controller;
 #endif
-	dev->weight = RX_WORK_PER_LOOP;
 #ifdef CONFIG_FORCEDETH_NAPI
-	dev->poll = nv_napi_poll;
+	netif_napi_add(dev, &np->napi, nv_napi_poll, RX_WORK_PER_LOOP);
 #endif
 	SET_ETHTOOL_OPS(dev, &ops);
 	dev->tx_timeout = nv_tx_timeout;