[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, 18 insertions, 18 deletions

diff --git a/drivers/net/epic100.c b/drivers/net/epic100.c
index 119778401e48..f8446e373bdd 100644
--- a/drivers/net/epic100.c
+++ b/drivers/net/epic100.c
@@ -262,6 +262,7 @@ struct epic_private {
         /* Ring pointers. */
         spinlock_t lock;                                /* Group with Tx control cache line. */
         spinlock_t napi_lock;
+        struct napi_struct napi;
         unsigned int reschedule_in_poll;
         unsigned int cur_tx, dirty_tx;
 
@@ -294,7 +295,7 @@ static void epic_tx_timeout(struct net_device *dev);
 static void epic_init_ring(struct net_device *dev);
 static int epic_start_xmit(struct sk_buff *skb, struct net_device *dev);
 static int epic_rx(struct net_device *dev, int budget);
-static int epic_poll(struct net_device *dev, int *budget);
+static int epic_poll(struct napi_struct *napi, int budget);
 static irqreturn_t epic_interrupt(int irq, void *dev_instance);
 static int netdev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
 static const struct ethtool_ops netdev_ethtool_ops;
@@ -487,8 +488,7 @@ static int __devinit epic_init_one (struct pci_dev *pdev,
         dev->ethtool_ops = &netdev_ethtool_ops;
         dev->watchdog_timeo = TX_TIMEOUT;
         dev->tx_timeout = &epic_tx_timeout;
-        dev->poll = epic_poll;
-        dev->weight = 64;
+        netif_napi_add(dev, &ep->napi, epic_poll, 64);
 
         ret = register_netdev(dev);
         if (ret < 0)
@@ -660,8 +660,11 @@ static int epic_open(struct net_device *dev)
         /* Soft reset the chip. */
         outl(0x4001, ioaddr + GENCTL);
 
-        if ((retval = request_irq(dev->irq, &epic_interrupt, IRQF_SHARED, dev->name, dev)))
+        napi_enable(&ep->napi);
+        if ((retval = request_irq(dev->irq, &epic_interrupt, IRQF_SHARED, dev->name, dev))) {
+                napi_disable(&ep->napi);
                 return retval;
+        }
 
         epic_init_ring(dev);
 
@@ -1103,9 +1106,9 @@ static irqreturn_t epic_interrupt(int irq, void *dev_instance)
 
         if ((status & EpicNapiEvent) && !ep->reschedule_in_poll) {
                 spin_lock(&ep->napi_lock);
-                if (netif_rx_schedule_prep(dev)) {
+                if (netif_rx_schedule_prep(dev, &ep->napi)) {
                         epic_napi_irq_off(dev, ep);
-                        __netif_rx_schedule(dev);
+                        __netif_rx_schedule(dev, &ep->napi);
                 } else
                         ep->reschedule_in_poll++;
                 spin_unlock(&ep->napi_lock);
@@ -1257,26 +1260,22 @@ static void epic_rx_err(struct net_device *dev, struct epic_private *ep)
                 outw(RxQueued, ioaddr + COMMAND);
 }
 
-static int epic_poll(struct net_device *dev, int *budget)
+static int epic_poll(struct napi_struct *napi, int budget)
 {
-        struct epic_private *ep = dev->priv;
-        int work_done = 0, orig_budget;
+        struct epic_private *ep = container_of(napi, struct epic_private, napi);
+        struct net_device *dev = ep->mii.dev;
+        int work_done = 0;
         long ioaddr = dev->base_addr;
 
-        orig_budget = (*budget > dev->quota) ? dev->quota : *budget;
-
 rx_action:
 
         epic_tx(dev, ep);
 
-        work_done += epic_rx(dev, *budget);
+        work_done += epic_rx(dev, budget);
 
         epic_rx_err(dev, ep);
 
-        *budget -= work_done;
-        dev->quota -= work_done;
-
-        if (netif_running(dev) && (work_done < orig_budget)) {
+        if (netif_running(dev) && (work_done < budget)) {
                 unsigned long flags;
                 int more;
 
@@ -1286,7 +1285,7 @@ rx_action:
 
                 more = ep->reschedule_in_poll;
                 if (!more) {
-                        __netif_rx_complete(dev);
+                        __netif_rx_complete(dev, napi);
                         outl(EpicNapiEvent, ioaddr + INTSTAT);
                         epic_napi_irq_on(dev, ep);
                 } else
@@ -1298,7 +1297,7 @@ rx_action:
                         goto rx_action;
         }
 
-        return (work_done >= orig_budget);
+        return work_done;
 }
 
 static int epic_close(struct net_device *dev)
@@ -1309,6 +1308,7 @@ static int epic_close(struct net_device *dev)
         int i;
 
         netif_stop_queue(dev);
+        napi_disable(&ep->napi);
 
         if (debug > 1)
                 printk(KERN_DEBUG "%s: Shutting down ethercard, status was %2.2x.\n",