[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, 22 deletions

diff --git a/drivers/net/macb.c b/drivers/net/macb.c
index a4bb026..74c3f7a 100644
--- a/drivers/net/macb.c
+++ b/drivers/net/macb.c
@@ -470,47 +470,41 @@ static int macb_rx(struct macb *bp, int budget)
 	return received;
 }
 
-static int macb_poll(struct net_device *dev, int *budget)
+static int macb_poll(struct napi_struct *napi, int budget)
 {
-	struct macb *bp = netdev_priv(dev);
-	int orig_budget, work_done, retval = 0;
+	struct macb *bp = container_of(napi, struct macb, napi);
+	struct net_device *dev = bp->dev;
+	int work_done;
 	u32 status;
 
 	status = macb_readl(bp, RSR);
 	macb_writel(bp, RSR, status);
 
+	work_done = 0;
 	if (!status) {
 		/*
 		 * This may happen if an interrupt was pending before
 		 * this function was called last time, and no packets
 		 * have been received since.
 		 */
-		netif_rx_complete(dev);
+		netif_rx_complete(dev, napi);
 		goto out;
 	}
 
 	dev_dbg(&bp->pdev->dev, "poll: status = %08lx, budget = %d\n",
-		(unsigned long)status, *budget);
+		(unsigned long)status, budget);
 
 	if (!(status & MACB_BIT(REC))) {
 		dev_warn(&bp->pdev->dev,
 			 "No RX buffers complete, status = %02lx\n",
 			 (unsigned long)status);
-		netif_rx_complete(dev);
+		netif_rx_complete(dev, napi);
 		goto out;
 	}
 
-	orig_budget = *budget;
-	if (orig_budget > dev->quota)
-		orig_budget = dev->quota;
-
-	work_done = macb_rx(bp, orig_budget);
-	if (work_done < orig_budget) {
-		netif_rx_complete(dev);
-		retval = 0;
-	} else {
-		retval = 1;
-	}
+	work_done = macb_rx(bp, budget);
+	if (work_done < budget)
+		netif_rx_complete(dev, napi);
 
 	/*
 	 * We've done what we can to clean the buffers. Make sure we
@@ -521,7 +515,7 @@ out:
 
 	/* TODO: Handle errors */
 
-	return retval;
+	return work_done;
 }
 
 static irqreturn_t macb_interrupt(int irq, void *dev_id)
@@ -545,7 +539,7 @@ static irqreturn_t macb_interrupt(int irq, void *dev_id)
 		}
 
 		if (status & MACB_RX_INT_FLAGS) {
-			if (netif_rx_schedule_prep(dev)) {
+			if (netif_rx_schedule_prep(dev, &bp->napi)) {
 				/*
 				 * There's no point taking any more interrupts
 				 * until we have processed the buffers
@@ -553,7 +547,7 @@ static irqreturn_t macb_interrupt(int irq, void *dev_id)
 				macb_writel(bp, IDR, MACB_RX_INT_FLAGS);
 				dev_dbg(&bp->pdev->dev,
 					"scheduling RX softirq\n");
-				__netif_rx_schedule(dev);
+				__netif_rx_schedule(dev, &bp->napi);
 			}
 		}
 
@@ -937,6 +931,8 @@ static int macb_open(struct net_device *dev)
 		return err;
 	}
 
+	napi_enable(&bp->napi);
+
 	macb_init_rings(bp);
 	macb_init_hw(bp);
 
@@ -954,6 +950,7 @@ static int macb_close(struct net_device *dev)
 	unsigned long flags;
 
 	netif_stop_queue(dev);
+	napi_disable(&bp->napi);
 
 	if (bp->phy_dev)
 		phy_stop(bp->phy_dev);
@@ -1146,8 +1143,7 @@ static int __devinit macb_probe(struct platform_device *pdev)
 	dev->get_stats = macb_get_stats;
 	dev->set_multicast_list = macb_set_rx_mode;
 	dev->do_ioctl = macb_ioctl;
-	dev->poll = macb_poll;
-	dev->weight = 64;
+	netif_napi_add(dev, &bp->napi, macb_poll, 64);
 	dev->ethtool_ops = &macb_ethtool_ops;
 
 	dev->base_addr = regs->start;