[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, 25 deletions

diff --git a/drivers/net/8139too.c b/drivers/net/8139too.c
index f4e4298d24b9..20af6baecfcb 100644
--- a/drivers/net/8139too.c
+++ b/drivers/net/8139too.c
@@ -573,6 +573,8 @@ struct rtl8139_private {
 	int drv_flags;
 	struct pci_dev *pci_dev;
 	u32 msg_enable;
+	struct napi_struct napi;
+	struct net_device *dev;
 	struct net_device_stats stats;
 	unsigned char *rx_ring;
 	unsigned int cur_rx;	/* Index into the Rx buffer of next Rx pkt. */
@@ -625,10 +627,10 @@ static void rtl8139_tx_timeout (struct net_device *dev);
 static void rtl8139_init_ring (struct net_device *dev);
 static int rtl8139_start_xmit (struct sk_buff *skb,
 			       struct net_device *dev);
-static int rtl8139_poll(struct net_device *dev, int *budget);
 #ifdef CONFIG_NET_POLL_CONTROLLER
 static void rtl8139_poll_controller(struct net_device *dev);
 #endif
+static int rtl8139_poll(struct napi_struct *napi, int budget);
 static irqreturn_t rtl8139_interrupt (int irq, void *dev_instance);
 static int rtl8139_close (struct net_device *dev);
 static int netdev_ioctl (struct net_device *dev, struct ifreq *rq, int cmd);
@@ -963,6 +965,7 @@ static int __devinit rtl8139_init_one (struct pci_dev *pdev,
 
 	assert (dev != NULL);
 	tp = netdev_priv(dev);
+	tp->dev = dev;
 
 	ioaddr = tp->mmio_addr;
 	assert (ioaddr != NULL);
@@ -976,8 +979,7 @@ static int __devinit rtl8139_init_one (struct pci_dev *pdev,
 	/* The Rtl8139-specific entries in the device structure. */
 	dev->open = rtl8139_open;
 	dev->hard_start_xmit = rtl8139_start_xmit;
-	dev->poll = rtl8139_poll;
-	dev->weight = 64;
+	netif_napi_add(dev, &tp->napi, rtl8139_poll, 64);
 	dev->stop = rtl8139_close;
 	dev->get_stats = rtl8139_get_stats;
 	dev->set_multicast_list = rtl8139_set_rx_mode;
@@ -1332,6 +1334,8 @@ static int rtl8139_open (struct net_device *dev)
 
 	}
 
+	napi_enable(&tp->napi);
+
 	tp->mii.full_duplex = tp->mii.force_media;
 	tp->tx_flag = (TX_FIFO_THRESH << 11) & 0x003f0000;
 
@@ -2103,39 +2107,32 @@ static void rtl8139_weird_interrupt (struct net_device *dev,
 	}
 }
 
-static int rtl8139_poll(struct net_device *dev, int *budget)
+static int rtl8139_poll(struct napi_struct *napi, int budget)
 {
-	struct rtl8139_private *tp = netdev_priv(dev);
+	struct rtl8139_private *tp = container_of(napi, struct rtl8139_private, napi);
+	struct net_device *dev = tp->dev;
 	void __iomem *ioaddr = tp->mmio_addr;
-	int orig_budget = min(*budget, dev->quota);
-	int done = 1;
+	int work_done;
 
 	spin_lock(&tp->rx_lock);
-	if (likely(RTL_R16(IntrStatus) & RxAckBits)) {
-		int work_done;
-
-		work_done = rtl8139_rx(dev, tp, orig_budget);
-		if (likely(work_done > 0)) {
-			*budget -= work_done;
-			dev->quota -= work_done;
-			done = (work_done < orig_budget);
-		}
-	}
+	work_done = 0;
+	if (likely(RTL_R16(IntrStatus) & RxAckBits))
+		work_done += rtl8139_rx(dev, tp, budget);
 
-	if (done) {
+	if (work_done < budget) {
 		unsigned long flags;
 		/*
 		 * Order is important since data can get interrupted
 		 * again when we think we are done.
 		 */
-		local_irq_save(flags);
+		spin_lock_irqsave(&tp->lock, flags);
 		RTL_W16_F(IntrMask, rtl8139_intr_mask);
-		__netif_rx_complete(dev);
-		local_irq_restore(flags);
+		__netif_rx_complete(dev, napi);
+		spin_unlock_irqrestore(&tp->lock, flags);
 	}
 	spin_unlock(&tp->rx_lock);
 
-	return !done;
+	return work_done;
 }
 
 /* The interrupt handler does all of the Rx thread work and cleans up
@@ -2180,9 +2177,9 @@ static irqreturn_t rtl8139_interrupt (int irq, void *dev_instance)
 	/* Receive packets are processed by poll routine.
 	   If not running start it now. */
 	if (status & RxAckBits){
-		if (netif_rx_schedule_prep(dev)) {
+		if (netif_rx_schedule_prep(dev, &tp->napi)) {
 			RTL_W16_F (IntrMask, rtl8139_norx_intr_mask);
-			__netif_rx_schedule (dev);
+			__netif_rx_schedule(dev, &tp->napi);
 		}
 	}
 
@@ -2223,7 +2220,8 @@ static int rtl8139_close (struct net_device *dev)
 	void __iomem *ioaddr = tp->mmio_addr;
 	unsigned long flags;
 
-	netif_stop_queue (dev);
+	netif_stop_queue(dev);
+	napi_disable(&tp->napi);
 
 	if (netif_msg_ifdown(tp))
 		printk(KERN_DEBUG "%s: Shutting down ethercard, status was 0x%4.4x.\n",