[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, 29 deletions

diff --git a/drivers/net/sb1250-mac.c b/drivers/net/sb1250-mac.c
index e7fdcf15b5a7..53845ebb649f 100644
--- a/drivers/net/sb1250-mac.c
+++ b/drivers/net/sb1250-mac.c
@@ -238,6 +238,7 @@ struct sbmac_softc {
          */
 
         struct net_device *sbm_dev;             /* pointer to linux device */
+        struct napi_struct napi;
         spinlock_t sbm_lock;            /* spin lock */
         struct timer_list sbm_timer;            /* for monitoring MII */
         struct net_device_stats sbm_stats;
@@ -320,7 +321,7 @@ static struct net_device_stats *sbmac_get_stats(struct net_device *dev);
 static void sbmac_set_rx_mode(struct net_device *dev);
 static int sbmac_mii_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
 static int sbmac_close(struct net_device *dev);
-static int sbmac_poll(struct net_device *poll_dev, int *budget);
+static int sbmac_poll(struct napi_struct *napi, int budget);
 
 static int sbmac_mii_poll(struct sbmac_softc *s,int noisy);
 static int sbmac_mii_probe(struct net_device *dev);
@@ -2154,20 +2155,13 @@ static irqreturn_t sbmac_intr(int irq,void *dev_instance)
          * Transmits on channel 0
          */
 
-        if (isr & (M_MAC_INT_CHANNEL << S_MAC_TX_CH0)) {
+        if (isr & (M_MAC_INT_CHANNEL << S_MAC_TX_CH0))
                 sbdma_tx_process(sc,&(sc->sbm_txdma), 0);
-#ifdef CONFIG_NETPOLL_TRAP
-                if (netpoll_trap()) {
-                        if (test_and_clear_bit(__LINK_STATE_XOFF, &dev->state))
-                                __netif_schedule(dev);
-                }
-#endif
-        }
 
         if (isr & (M_MAC_INT_CHANNEL << S_MAC_RX_CH0)) {
-                if (netif_rx_schedule_prep(dev)) {
+                if (netif_rx_schedule_prep(dev, &sc->napi)) {
                         __raw_writeq(0, sc->sbm_imr);
-                        __netif_rx_schedule(dev);
+                        __netif_rx_schedule(dev, &sc->napi);
                         /* Depend on the exit from poll to reenable intr */
                 }
                 else {
@@ -2470,8 +2464,8 @@ static int sbmac_init(struct net_device *dev, int idx)
         dev->do_ioctl           = sbmac_mii_ioctl;
         dev->tx_timeout         = sbmac_tx_timeout;
         dev->watchdog_timeo     = TX_TIMEOUT;
-        dev->poll               = sbmac_poll;
-        dev->weight             = 16;
+
+        netif_napi_add(dev, &sc->napi, sbmac_poll, 16);
 
         dev->change_mtu         = sb1250_change_mtu;
 #ifdef CONFIG_NET_POLL_CONTROLLER
@@ -2537,6 +2531,8 @@ static int sbmac_open(struct net_device *dev)
                 return -EINVAL;
         }
 
+        napi_enable(&sc->napi);
+
         /*
          * Configure default speed
          */
@@ -2850,6 +2846,8 @@ static int sbmac_close(struct net_device *dev)
         unsigned long flags;
         int irq;
 
+        napi_disable(&sc->napi);
+
         sbmac_set_channel_state(sc,sbmac_state_off);
 
         del_timer_sync(&sc->sbm_timer);
@@ -2874,26 +2872,17 @@ static int sbmac_close(struct net_device *dev)
         return 0;
 }
 
-static int sbmac_poll(struct net_device *dev, int *budget)
+static int sbmac_poll(struct napi_struct *napi, int budget)
 {
-        int work_to_do;
+        struct sbmac_softc *sc = container_of(napi, struct sbmac_softc, napi);
+        struct net_device *dev = sc->sbm_dev;
         int work_done;
-        struct sbmac_softc *sc = netdev_priv(dev);
-
-        work_to_do = min(*budget, dev->quota);
-        work_done = sbdma_rx_process(sc, &(sc->sbm_rxdma), work_to_do, 1);
-
-        if (work_done > work_to_do)
-                printk(KERN_ERR "%s exceeded work_to_do budget=%d quota=%d work-done=%d\n",
-                       sc->sbm_dev->name, *budget, dev->quota, work_done);
 
+        work_done = sbdma_rx_process(sc, &(sc->sbm_rxdma), budget, 1);
         sbdma_tx_process(sc, &(sc->sbm_txdma), 1);
 
-        *budget -= work_done;
-        dev->quota -= work_done;
-
-        if (work_done < work_to_do) {
-                netif_rx_complete(dev);
+        if (work_done < budget) {
+                netif_rx_complete(dev, napi);
 
 #ifdef CONFIG_SBMAC_COALESCE
                 __raw_writeq(((M_MAC_INT_EOP_COUNT | M_MAC_INT_EOP_TIMER) << S_MAC_TX_CH0) |
@@ -2905,7 +2894,7 @@ static int sbmac_poll(struct net_device *dev, int *budget)
 #endif
         }
 
-        return (work_done >= work_to_do);
+        return work_done;
 }
 
 #if defined(SBMAC_ETH0_HWADDR) || defined(SBMAC_ETH1_HWADDR) || defined(SBMAC_ETH2_HWADDR) || defined(SBMAC_ETH3_HWADDR)