[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, 30 deletions

diff --git a/drivers/net/b44.c b/drivers/net/b44.c
index 0795df235492..b92b3e25c42a 100644
--- a/drivers/net/b44.c
+++ b/drivers/net/b44.c
@@ -848,10 +848,11 @@ static int b44_rx(struct b44 *bp, int budget)
         return received;
 }
 
-static int b44_poll(struct net_device *netdev, int *budget)
+static int b44_poll(struct napi_struct *napi, int budget)
 {
-        struct b44 *bp = netdev_priv(netdev);
-        int done;
+        struct b44 *bp = container_of(napi, struct b44, napi);
+        struct net_device *netdev = bp->dev;
+        int work_done;
 
         spin_lock_irq(&bp->lock);
 
@@ -862,22 +863,9 @@ static int b44_poll(struct net_device *netdev, int *budget)
         }
         spin_unlock_irq(&bp->lock);
 
-        done = 1;
-        if (bp->istat & ISTAT_RX) {
-                int orig_budget = *budget;
-                int work_done;
-
-                if (orig_budget > netdev->quota)
-                        orig_budget = netdev->quota;
-
-                work_done = b44_rx(bp, orig_budget);
-
-                *budget -= work_done;
-                netdev->quota -= work_done;
-
-                if (work_done >= orig_budget)
-                        done = 0;
-        }
+        work_done = 0;
+        if (bp->istat & ISTAT_RX)
+                work_done += b44_rx(bp, budget);
 
         if (bp->istat & ISTAT_ERRORS) {
                 unsigned long flags;
@@ -888,15 +876,15 @@ static int b44_poll(struct net_device *netdev, int *budget)
                 b44_init_hw(bp, B44_FULL_RESET_SKIP_PHY);
                 netif_wake_queue(bp->dev);
                 spin_unlock_irqrestore(&bp->lock, flags);
-                done = 1;
+                work_done = 0;
         }
 
-        if (done) {
-                netif_rx_complete(netdev);
+        if (work_done < budget) {
+                netif_rx_complete(netdev, napi);
                 b44_enable_ints(bp);
         }
 
-        return (done ? 0 : 1);
+        return work_done;
 }
 
 static irqreturn_t b44_interrupt(int irq, void *dev_id)
@@ -924,13 +912,13 @@ static irqreturn_t b44_interrupt(int irq, void *dev_id)
                         goto irq_ack;
                 }
 
-                if (netif_rx_schedule_prep(dev)) {
+                if (netif_rx_schedule_prep(dev, &bp->napi)) {
                         /* NOTE: These writes are posted by the readback of
                          *       the ISTAT register below.
                          */
                         bp->istat = istat;
                         __b44_disable_ints(bp);
-                        __netif_rx_schedule(dev);
+                        __netif_rx_schedule(dev, &bp->napi);
                 } else {
                         printk(KERN_ERR PFX "%s: Error, poll already scheduled\n",
                                dev->name);
@@ -1420,6 +1408,8 @@ static int b44_open(struct net_device *dev)
         if (err)
                 goto out;
 
+        napi_enable(&bp->napi);
+
         b44_init_rings(bp);
         b44_init_hw(bp, B44_FULL_RESET);
 
@@ -1427,6 +1417,7 @@ static int b44_open(struct net_device *dev)
 
         err = request_irq(dev->irq, b44_interrupt, IRQF_SHARED, dev->name, dev);
         if (unlikely(err < 0)) {
+                napi_disable(&bp->napi);
                 b44_chip_reset(bp);
                 b44_free_rings(bp);
                 b44_free_consistent(bp);
@@ -1609,7 +1600,7 @@ static int b44_close(struct net_device *dev)
 
         netif_stop_queue(dev);
 
-        netif_poll_disable(dev);
+        napi_disable(&bp->napi);
 
         del_timer_sync(&bp->timer);
 
@@ -1626,8 +1617,6 @@ static int b44_close(struct net_device *dev)
 
         free_irq(dev->irq, dev);
 
-        netif_poll_enable(dev);
-
         if (bp->flags & B44_FLAG_WOL_ENABLE) {
                 b44_init_hw(bp, B44_PARTIAL_RESET);
                 b44_setup_wol(bp);
@@ -2194,8 +2183,7 @@ static int __devinit b44_init_one(struct pci_dev *pdev,
         dev->set_mac_address = b44_set_mac_addr;
         dev->do_ioctl = b44_ioctl;
         dev->tx_timeout = b44_tx_timeout;
-        dev->poll = b44_poll;
-        dev->weight = 64;
+        netif_napi_add(dev, &bp->napi, b44_poll, 64);
         dev->watchdog_timeo = B44_TX_TIMEOUT;
 #ifdef CONFIG_NET_POLL_CONTROLLER
         dev->poll_controller = b44_poll_controller;