[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, 28 insertions, 23 deletions

diff --git a/drivers/net/starfire.c b/drivers/net/starfire.c
index 8b6478663a56..3b9336c34206 100644
--- a/drivers/net/starfire.c
+++ b/drivers/net/starfire.c
@@ -178,16 +178,13 @@ static int full_duplex[MAX_UNITS] = {0, };
 #define skb_num_frags(skb) (skb_shinfo(skb)->nr_frags + 1)
 
 #ifdef HAVE_NETDEV_POLL
-#define init_poll(dev) \
-do { \
-        dev->poll = &netdev_poll; \
-        dev->weight = max_interrupt_work; \
-} while (0)
-#define netdev_rx(dev, ioaddr) \
+#define init_poll(dev, np) \
+        netif_napi_add(dev, &np->napi, netdev_poll, max_interrupt_work)
+#define netdev_rx(dev, np, ioaddr) \
 do { \
         u32 intr_enable; \
-        if (netif_rx_schedule_prep(dev)) { \
-                __netif_rx_schedule(dev); \
+        if (netif_rx_schedule_prep(dev, &np->napi)) { \
+                __netif_rx_schedule(dev, &np->napi); \
                 intr_enable = readl(ioaddr + IntrEnable); \
                 intr_enable &= ~(IntrRxDone | IntrRxEmpty); \
                 writel(intr_enable, ioaddr + IntrEnable); \
@@ -204,12 +201,12 @@ do { \
 } while (0)
 #define netdev_receive_skb(skb) netif_receive_skb(skb)
 #define vlan_netdev_receive_skb(skb, vlgrp, vlid) vlan_hwaccel_receive_skb(skb, vlgrp, vlid)
-static int      netdev_poll(struct net_device *dev, int *budget);
+static int      netdev_poll(struct napi_struct *napi, int budget);
 #else  /* not HAVE_NETDEV_POLL */
-#define init_poll(dev)
+#define init_poll(dev, np)
 #define netdev_receive_skb(skb) netif_rx(skb)
 #define vlan_netdev_receive_skb(skb, vlgrp, vlid) vlan_hwaccel_rx(skb, vlgrp, vlid)
-#define netdev_rx(dev, ioaddr) \
+#define netdev_rx(dev, np, ioaddr) \
 do { \
         int quota = np->dirty_rx + RX_RING_SIZE - np->cur_rx; \
         __netdev_rx(dev, &quota);\
@@ -599,6 +596,8 @@ struct netdev_private {
         struct tx_done_desc *tx_done_q;
         dma_addr_t tx_done_q_dma;
         unsigned int tx_done;
+        struct napi_struct napi;
+        struct net_device *dev;
         struct net_device_stats stats;
         struct pci_dev *pci_dev;
 #ifdef VLAN_SUPPORT
@@ -791,6 +790,7 @@ static int __devinit starfire_init_one(struct pci_dev *pdev,
         dev->irq = irq;
 
         np = netdev_priv(dev);
+        np->dev = dev;
         np->base = base;
         spin_lock_init(&np->lock);
         pci_set_drvdata(pdev, dev);
@@ -851,7 +851,7 @@ static int __devinit starfire_init_one(struct pci_dev *pdev,
         dev->hard_start_xmit = &start_tx;
         dev->tx_timeout = tx_timeout;
         dev->watchdog_timeo = TX_TIMEOUT;
-        init_poll(dev);
+        init_poll(dev, np);
         dev->stop = &netdev_close;
         dev->get_stats = &get_stats;
         dev->set_multicast_list = &set_rx_mode;
@@ -1056,6 +1056,9 @@ static int netdev_open(struct net_device *dev)
 
         writel(np->intr_timer_ctrl, ioaddr + IntrTimerCtrl);
 
+#ifdef HAVE_NETDEV_POLL
+        napi_enable(&np->napi);
+#endif
         netif_start_queue(dev);
 
         if (debug > 1)
@@ -1330,7 +1333,7 @@ static irqreturn_t intr_handler(int irq, void *dev_instance)
                 handled = 1;
 
                 if (intr_status & (IntrRxDone | IntrRxEmpty))
-                        netdev_rx(dev, ioaddr);
+                        netdev_rx(dev, np, ioaddr);
 
                 /* Scavenge the skbuff list based on the Tx-done queue.
                    There are redundant checks here that may be cleaned up
@@ -1531,36 +1534,35 @@ static int __netdev_rx(struct net_device *dev, int *quota)
 
 
 #ifdef HAVE_NETDEV_POLL
-static int netdev_poll(struct net_device *dev, int *budget)
+static int netdev_poll(struct napi_struct *napi, int budget)
 {
+        struct netdev_private *np = container_of(napi, struct netdev_private, napi);
+        struct net_device *dev = np->dev;
         u32 intr_status;
-        struct netdev_private *np = netdev_priv(dev);
         void __iomem *ioaddr = np->base;
-        int retcode = 0, quota = dev->quota;
+        int quota = budget;
 
         do {
                 writel(IntrRxDone | IntrRxEmpty, ioaddr + IntrClear);
 
-                retcode = __netdev_rx(dev, &quota);
-                *budget -= (dev->quota - quota);
-                dev->quota = quota;
-                if (retcode)
+                if (__netdev_rx(dev, &quota))
                         goto out;
 
                 intr_status = readl(ioaddr + IntrStatus);
         } while (intr_status & (IntrRxDone | IntrRxEmpty));
 
-        netif_rx_complete(dev);
+        netif_rx_complete(dev, napi);
         intr_status = readl(ioaddr + IntrEnable);
         intr_status |= IntrRxDone | IntrRxEmpty;
         writel(intr_status, ioaddr + IntrEnable);
 
  out:
         if (debug > 5)
-                printk(KERN_DEBUG "  exiting netdev_poll(): %d.\n", retcode);
+                printk(KERN_DEBUG "  exiting netdev_poll(): %d.\n",
+                       budget - quota);
 
         /* Restart Rx engine if stopped. */
-        return retcode;
+        return budget - quota;
 }
 #endif /* HAVE_NETDEV_POLL */
 
@@ -1904,6 +1906,9 @@ static int netdev_close(struct net_device *dev)
         int i;
 
         netif_stop_queue(dev);
+#ifdef HAVE_NETDEV_POLL
+        napi_disable(&np->napi);
+#endif
 
         if (debug > 1) {
                 printk(KERN_DEBUG "%s: Shutting down ethercard, Intr status %#8.8x.\n",