[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, 19 insertions, 28 deletions

diff --git a/drivers/net/typhoon.c b/drivers/net/typhoon.c
index 0358720..0377b8b 100644
--- a/drivers/net/typhoon.c
+++ b/drivers/net/typhoon.c
@@ -284,6 +284,7 @@ struct typhoon {
 	struct basic_ring	rxLoRing;
 	struct pci_dev *	pdev;
 	struct net_device *	dev;
+	struct napi_struct	napi;
 	spinlock_t		state_lock;
 	struct vlan_group *	vlgrp;
 	struct basic_ring	rxHiRing;
@@ -1759,12 +1760,12 @@ typhoon_fill_free_ring(struct typhoon *tp)
 }
 
 static int
-typhoon_poll(struct net_device *dev, int *total_budget)
+typhoon_poll(struct napi_struct *napi, int budget)
 {
-	struct typhoon *tp = netdev_priv(dev);
+	struct typhoon *tp = container_of(napi, struct typhoon, napi);
+	struct net_device *dev = tp->dev;
 	struct typhoon_indexes *indexes = tp->indexes;
-	int orig_budget = *total_budget;
-	int budget, work_done, done;
+	int work_done;
 
 	rmb();
 	if(!tp->awaiting_resp && indexes->respReady != indexes->respCleared)
@@ -1773,30 +1774,16 @@ typhoon_poll(struct net_device *dev, int *total_budget)
 	if(le32_to_cpu(indexes->txLoCleared) != tp->txLoRing.lastRead)
 		typhoon_tx_complete(tp, &tp->txLoRing, &indexes->txLoCleared);
 
-	if(orig_budget > dev->quota)
-		orig_budget = dev->quota;
-
-	budget = orig_budget;
 	work_done = 0;
-	done = 1;
 
 	if(indexes->rxHiCleared != indexes->rxHiReady) {
-		work_done = typhoon_rx(tp, &tp->rxHiRing, &indexes->rxHiReady,
+		work_done += typhoon_rx(tp, &tp->rxHiRing, &indexes->rxHiReady,
 			   		&indexes->rxHiCleared, budget);
-		budget -= work_done;
 	}
 
 	if(indexes->rxLoCleared != indexes->rxLoReady) {
 		work_done += typhoon_rx(tp, &tp->rxLoRing, &indexes->rxLoReady,
-			   		&indexes->rxLoCleared, budget);
-	}
-
-	if(work_done) {
-		*total_budget -= work_done;
-		dev->quota -= work_done;
-
-		if(work_done >= orig_budget)
-			done = 0;
+					&indexes->rxLoCleared, budget - work_done);
 	}
 
 	if(le32_to_cpu(indexes->rxBuffCleared) == tp->rxBuffRing.lastWrite) {
@@ -1804,14 +1791,14 @@ typhoon_poll(struct net_device *dev, int *total_budget)
 		typhoon_fill_free_ring(tp);
 	}
 
-	if(done) {
-		netif_rx_complete(dev);
+	if (work_done < budget) {
+		netif_rx_complete(dev, napi);
 		iowrite32(TYPHOON_INTR_NONE,
 				tp->ioaddr + TYPHOON_REG_INTR_MASK);
 		typhoon_post_pci_writes(tp->ioaddr);
 	}
 
-	return (done ? 0 : 1);
+	return work_done;
 }
 
 static irqreturn_t
@@ -1828,10 +1815,10 @@ typhoon_interrupt(int irq, void *dev_instance)
 
 	iowrite32(intr_status, ioaddr + TYPHOON_REG_INTR_STATUS);
 
-	if(netif_rx_schedule_prep(dev)) {
+	if (netif_rx_schedule_prep(dev, &tp->napi)) {
 		iowrite32(TYPHOON_INTR_ALL, ioaddr + TYPHOON_REG_INTR_MASK);
 		typhoon_post_pci_writes(ioaddr);
-		__netif_rx_schedule(dev);
+		__netif_rx_schedule(dev, &tp->napi);
 	} else {
 		printk(KERN_ERR "%s: Error, poll already scheduled\n",
                        dev->name);
@@ -2119,9 +2106,13 @@ typhoon_open(struct net_device *dev)
 	if(err < 0)
 		goto out_sleep;
 
+	napi_enable(&tp->napi);
+
 	err = typhoon_start_runtime(tp);
-	if(err < 0)
+	if(err < 0) {
+		napi_disable(&tp->napi);
 		goto out_irq;
+	}
 
 	netif_start_queue(dev);
 	return 0;
@@ -2150,6 +2141,7 @@ typhoon_close(struct net_device *dev)
 	struct typhoon *tp = netdev_priv(dev);
 
 	netif_stop_queue(dev);
+	napi_disable(&tp->napi);
 
 	if(typhoon_stop_runtime(tp, WaitSleep) < 0)
 		printk(KERN_ERR "%s: unable to stop runtime\n", dev->name);
@@ -2521,8 +2513,7 @@ typhoon_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	dev->stop		= typhoon_close;
 	dev->set_multicast_list	= typhoon_set_rx_mode;
 	dev->tx_timeout		= typhoon_tx_timeout;
-	dev->poll		= typhoon_poll;
-	dev->weight		= 16;
+	netif_napi_add(dev, &tp->napi, typhoon_poll, 16);
 	dev->watchdog_timeo	= TX_TIMEOUT;
 	dev->get_stats		= typhoon_get_stats;
 	dev->set_mac_address	= typhoon_set_mac_address;