[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, 23 insertions, 24 deletions

diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
index f92690555dd..bd2de325bbd 100644
--- a/drivers/net/gianfar.c
+++ b/drivers/net/gianfar.c
@@ -134,7 +134,7 @@ static void gfar_configure_serdes(struct net_device *dev);
 extern int gfar_local_mdio_write(struct gfar_mii *regs, int mii_id, int regnum, u16 value);
 extern int gfar_local_mdio_read(struct gfar_mii *regs, int mii_id, int regnum);
 #ifdef CONFIG_GFAR_NAPI
-static int gfar_poll(struct net_device *dev, int *budget);
+static int gfar_poll(struct napi_struct *napi, int budget);
 #endif
 #ifdef CONFIG_NET_POLL_CONTROLLER
 static void gfar_netpoll(struct net_device *dev);
@@ -188,6 +188,7 @@ static int gfar_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	priv = netdev_priv(dev);
+	priv->dev = dev;
 
 	/* Set the info in the priv to the current info */
 	priv->einfo = einfo;
@@ -261,10 +262,7 @@ static int gfar_probe(struct platform_device *pdev)
 	dev->hard_start_xmit = gfar_start_xmit;
 	dev->tx_timeout = gfar_timeout;
 	dev->watchdog_timeo = TX_TIMEOUT;
-#ifdef CONFIG_GFAR_NAPI
-	dev->poll = gfar_poll;
-	dev->weight = GFAR_DEV_WEIGHT;
-#endif
+	netif_napi_add(dev, &priv->napi, gfar_poll, GFAR_DEV_WEIGHT);
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	dev->poll_controller = gfar_netpoll;
 #endif
@@ -939,6 +937,8 @@ static int gfar_enet_open(struct net_device *dev)
 {
 	int err;
 
+	napi_enable(&priv->napi);
+
 	/* Initialize a bunch of registers */
 	init_registers(dev);
 
@@ -946,10 +946,14 @@ static int gfar_enet_open(struct net_device *dev)
 
 	err = init_phy(dev);
 
-	if(err)
+	if(err) {
+		napi_disable(&priv->napi);
 		return err;
+	}
 
 	err = startup_gfar(dev);
+	if (err)
+		napi_disable(&priv->napi);
 
 	netif_start_queue(dev);
 
@@ -1102,6 +1106,9 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
 static int gfar_close(struct net_device *dev)
 {
 	struct gfar_private *priv = netdev_priv(dev);
+
+	napi_disable(&priv->napi);
+
 	stop_gfar(dev);
 
 	/* Disconnect from the PHY */
@@ -1318,7 +1325,7 @@ struct sk_buff * gfar_new_skb(struct net_device *dev, struct rxbd8 *bdp)
 		return NULL;
 
 	alignamount = RXBUF_ALIGNMENT -
-		(((unsigned) skb->data) & (RXBUF_ALIGNMENT - 1));
+		(((unsigned long) skb->data) & (RXBUF_ALIGNMENT - 1));
 
 	/* We need the data buffer to be aligned properly.  We will reserve
 	 * as many bytes as needed to align the data properly
@@ -1390,12 +1397,12 @@ irqreturn_t gfar_receive(int irq, void *dev_id)
 
 	/* support NAPI */
 #ifdef CONFIG_GFAR_NAPI
-	if (netif_rx_schedule_prep(dev)) {
+	if (netif_rx_schedule_prep(dev, &priv->napi)) {
 		tempval = gfar_read(&priv->regs->imask);
 		tempval &= IMASK_RX_DISABLED;
 		gfar_write(&priv->regs->imask, tempval);
 
-		__netif_rx_schedule(dev);
+		__netif_rx_schedule(dev, &priv->napi);
 	} else {
 		if (netif_msg_rx_err(priv))
 			printk(KERN_DEBUG "%s: receive called twice (%x)[%x]\n",
@@ -1569,23 +1576,16 @@ int gfar_clean_rx_ring(struct net_device *dev, int rx_work_limit)
 }
 
 #ifdef CONFIG_GFAR_NAPI
-static int gfar_poll(struct net_device *dev, int *budget)
+static int gfar_poll(struct napi_struct *napi, int budget)
 {
+	struct gfar_private *priv = container_of(napi, struct gfar_private, napi);
+	struct net_device *dev = priv->dev;
 	int howmany;
-	struct gfar_private *priv = netdev_priv(dev);
-	int rx_work_limit = *budget;
-
-	if (rx_work_limit > dev->quota)
-		rx_work_limit = dev->quota;
 
-	howmany = gfar_clean_rx_ring(dev, rx_work_limit);
+	howmany = gfar_clean_rx_ring(dev, budget);
 
-	dev->quota -= howmany;
-	rx_work_limit -= howmany;
-	*budget -= howmany;
-
-	if (rx_work_limit > 0) {
-		netif_rx_complete(dev);
+	if (howmany < budget) {
+		netif_rx_complete(dev, napi);
 
 		/* Clear the halt bit in RSTAT */
 		gfar_write(&priv->regs->rstat, RSTAT_CLEAR_RHALT);
@@ -1601,8 +1601,7 @@ static int gfar_poll(struct net_device *dev, int *budget)
 			gfar_write(&priv->regs->rxic, 0);
 	}
 
-	/* Return 1 if there's more work to do */
-	return (rx_work_limit > 0) ? 0 : 1;
+	return howmany;
 }
 #endif