[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, 33 deletions

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 9034a05734ef..ef1e3d1173c4 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -574,7 +574,7 @@ static void tg3_restart_ints(struct tg3 *tp)
 static inline void tg3_netif_stop(struct tg3 *tp)
 {
         tp->dev->trans_start = jiffies; /* prevent tx timeout */
-        netif_poll_disable(tp->dev);
+        napi_disable(&tp->napi);
         netif_tx_disable(tp->dev);
 }
 
@@ -585,7 +585,7 @@ static inline void tg3_netif_start(struct tg3 *tp)
          * so long as all callers are assured to have free tx slots
          * (such as after tg3_init_hw)
          */
-        netif_poll_enable(tp->dev);
+        napi_enable(&tp->napi);
         tp->hw_status->status |= SD_STATUS_UPDATED;
         tg3_enable_ints(tp);
 }
@@ -3471,11 +3471,12 @@ next_pkt_nopost:
         return received;
 }
 
-static int tg3_poll(struct net_device *netdev, int *budget)
+static int tg3_poll(struct napi_struct *napi, int budget)
 {
-        struct tg3 *tp = netdev_priv(netdev);
+        struct tg3 *tp = container_of(napi, struct tg3, napi);
+        struct net_device *netdev = tp->dev;
         struct tg3_hw_status *sblk = tp->hw_status;
-        int done;
+        int work_done = 0;
 
         /* handle link change and other phy events */
         if (!(tp->tg3_flags &
@@ -3494,7 +3495,7 @@ static int tg3_poll(struct net_device *netdev, int *budget)
         if (sblk->idx[0].tx_consumer != tp->tx_cons) {
                 tg3_tx(tp);
                 if (unlikely(tp->tg3_flags & TG3_FLAG_TX_RECOVERY_PENDING)) {
-                        netif_rx_complete(netdev);
+                        netif_rx_complete(netdev, napi);
                         schedule_work(&tp->reset_task);
                         return 0;
                 }
@@ -3502,20 +3503,10 @@ static int tg3_poll(struct net_device *netdev, int *budget)
 
         /* run RX thread, within the bounds set by NAPI.
          * All RX "locking" is done by ensuring outside
-         * code synchronizes with dev->poll()
+         * code synchronizes with tg3->napi.poll()
          */
-        if (sblk->idx[0].rx_producer != tp->rx_rcb_ptr) {
-                int orig_budget = *budget;
-                int work_done;
-
-                if (orig_budget > netdev->quota)
-                        orig_budget = netdev->quota;
-
-                work_done = tg3_rx(tp, orig_budget);
-
-                *budget -= work_done;
-                netdev->quota -= work_done;
-        }
+        if (sblk->idx[0].rx_producer != tp->rx_rcb_ptr)
+                work_done = tg3_rx(tp, budget);
 
         if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS) {
                 tp->last_tag = sblk->status_tag;
@@ -3524,13 +3515,12 @@ static int tg3_poll(struct net_device *netdev, int *budget)
                 sblk->status &= ~SD_STATUS_UPDATED;
 
         /* if no more work, tell net stack and NIC we're done */
-        done = !tg3_has_work(tp);
-        if (done) {
-                netif_rx_complete(netdev);
+        if (!tg3_has_work(tp)) {
+                netif_rx_complete(netdev, napi);
                 tg3_restart_ints(tp);
         }
 
-        return (done ? 0 : 1);
+        return work_done;
 }
 
 static void tg3_irq_quiesce(struct tg3 *tp)
@@ -3577,7 +3567,7 @@ static irqreturn_t tg3_msi_1shot(int irq, void *dev_id)
         prefetch(&tp->rx_rcb[tp->rx_rcb_ptr]);
 
         if (likely(!tg3_irq_sync(tp)))
-                netif_rx_schedule(dev);         /* schedule NAPI poll */
+                netif_rx_schedule(dev, &tp->napi);
 
         return IRQ_HANDLED;
 }
@@ -3602,7 +3592,7 @@ static irqreturn_t tg3_msi(int irq, void *dev_id)
          */
         tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, 0x00000001);
         if (likely(!tg3_irq_sync(tp)))
-                netif_rx_schedule(dev);         /* schedule NAPI poll */
+                netif_rx_schedule(dev, &tp->napi);
 
         return IRQ_RETVAL(1);
 }
@@ -3644,7 +3634,7 @@ static irqreturn_t tg3_interrupt(int irq, void *dev_id)
         sblk->status &= ~SD_STATUS_UPDATED;
         if (likely(tg3_has_work(tp))) {
                 prefetch(&tp->rx_rcb[tp->rx_rcb_ptr]);
-                netif_rx_schedule(dev);         /* schedule NAPI poll */
+                netif_rx_schedule(dev, &tp->napi);
         } else {
                 /* No work, shared interrupt perhaps?  re-enable
                  * interrupts, and flush that PCI write
@@ -3690,7 +3680,7 @@ static irqreturn_t tg3_interrupt_tagged(int irq, void *dev_id)
         tw32_mailbox_f(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, 0x00000001);
         if (tg3_irq_sync(tp))
                 goto out;
-        if (netif_rx_schedule_prep(dev)) {
+        if (netif_rx_schedule_prep(dev, &tp->napi)) {
                 prefetch(&tp->rx_rcb[tp->rx_rcb_ptr]);
                 /* Update last_tag to mark that this status has been
                  * seen. Because interrupt may be shared, we may be
@@ -3698,7 +3688,7 @@ static irqreturn_t tg3_interrupt_tagged(int irq, void *dev_id)
                  * if tg3_poll() is not scheduled.
                  */
                 tp->last_tag = sblk->status_tag;
-                __netif_rx_schedule(dev);
+                __netif_rx_schedule(dev, &tp->napi);
         }
 out:
         return IRQ_RETVAL(handled);
@@ -3737,7 +3727,7 @@ static int tg3_restart_hw(struct tg3 *tp, int reset_phy)
                 tg3_full_unlock(tp);
                 del_timer_sync(&tp->timer);
                 tp->irq_sync = 0;
-                netif_poll_enable(tp->dev);
+                napi_enable(&tp->napi);
                 dev_close(tp->dev);
                 tg3_full_lock(tp, 0);
         }
@@ -3932,7 +3922,7 @@ static int tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)
         len = skb_headlen(skb);
 
         /* We are running in BH disabled context with netif_tx_lock
-         * and TX reclaim runs via tp->poll inside of a software
+         * and TX reclaim runs via tp->napi.poll inside of a software
          * interrupt.  Furthermore, IRQ processing runs lockless so we have
          * no IRQ context deadlocks to worry about either.  Rejoice!
          */
@@ -4087,7 +4077,7 @@ static int tg3_start_xmit_dma_bug(struct sk_buff *skb, struct net_device *dev)
         len = skb_headlen(skb);
 
         /* We are running in BH disabled context with netif_tx_lock
-         * and TX reclaim runs via tp->poll inside of a software
+         * and TX reclaim runs via tp->napi.poll inside of a software
          * interrupt.  Furthermore, IRQ processing runs lockless so we have
          * no IRQ context deadlocks to worry about either.  Rejoice!
          */
@@ -7147,6 +7137,8 @@ static int tg3_open(struct net_device *dev)
                 return err;
         }
 
+        napi_enable(&tp->napi);
+
         tg3_full_lock(tp, 0);
 
         err = tg3_init_hw(tp, 1);
@@ -7174,6 +7166,7 @@ static int tg3_open(struct net_device *dev)
         tg3_full_unlock(tp);
 
         if (err) {
+                napi_disable(&tp->napi);
                 free_irq(tp->pdev->irq, dev);
                 if (tp->tg3_flags2 & TG3_FLG2_USING_MSI) {
                         pci_disable_msi(tp->pdev);
@@ -7199,6 +7192,8 @@ static int tg3_open(struct net_device *dev)
 
                         tg3_full_unlock(tp);
 
+                        napi_disable(&tp->napi);
+
                         return err;
                 }
 
@@ -7460,6 +7455,7 @@ static int tg3_close(struct net_device *dev)
 {
         struct tg3 *tp = netdev_priv(dev);
 
+        napi_disable(&tp->napi);
         cancel_work_sync(&tp->reset_task);
 
         netif_stop_queue(dev);
@@ -11900,9 +11896,8 @@ static int __devinit tg3_init_one(struct pci_dev *pdev,
         dev->set_mac_address = tg3_set_mac_addr;
         dev->do_ioctl = tg3_ioctl;
         dev->tx_timeout = tg3_tx_timeout;
-        dev->poll = tg3_poll;
+        netif_napi_add(dev, &tp->napi, tg3_poll, 64);
         dev->ethtool_ops = &tg3_ethtool_ops;
-        dev->weight = 64;
         dev->watchdog_timeo = TG3_TX_TIMEOUT;
         dev->change_mtu = tg3_change_mtu;
         dev->irq = pdev->irq;