[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, 27 insertions, 22 deletions

diff --git a/drivers/net/tc35815.c b/drivers/net/tc35815.c
index ec41469eee82..b5e0dff67230 100644
--- a/drivers/net/tc35815.c
+++ b/drivers/net/tc35815.c
@@ -414,6 +414,9 @@ enum tc35815_timer_state {
 struct tc35815_local {
         struct pci_dev *pci_dev;
 
+        struct net_device *dev;
+        struct napi_struct napi;
+
         /* statistics */
         struct net_device_stats stats;
         struct {
@@ -566,7 +569,7 @@ static int	tc35815_send_packet(struct sk_buff *skb, struct net_device *dev);
 static irqreturn_t      tc35815_interrupt(int irq, void *dev_id);
 #ifdef TC35815_NAPI
 static int      tc35815_rx(struct net_device *dev, int limit);
-static int      tc35815_poll(struct net_device *dev, int *budget);
+static int      tc35815_poll(struct napi_struct *napi, int budget);
 #else
 static void     tc35815_rx(struct net_device *dev);
 #endif
@@ -685,6 +688,7 @@ static int __devinit tc35815_init_one (struct pci_dev *pdev,
         SET_MODULE_OWNER(dev);
         SET_NETDEV_DEV(dev, &pdev->dev);
         lp = dev->priv;
+        lp->dev = dev;
 
         /* enable device (incl. PCI PM wakeup), and bus-mastering */
         rc = pci_enable_device (pdev);
@@ -738,8 +742,7 @@ static int __devinit tc35815_init_one (struct pci_dev *pdev,
         dev->tx_timeout = tc35815_tx_timeout;
         dev->watchdog_timeo = TC35815_TX_TIMEOUT;
 #ifdef TC35815_NAPI
-        dev->poll = tc35815_poll;
-        dev->weight = NAPI_WEIGHT;
+        netif_napi_add(dev, &lp->napi, tc35815_poll, NAPI_WEIGHT);
 #endif
 #ifdef CONFIG_NET_POLL_CONTROLLER
         dev->poll_controller = tc35815_poll_controller;
@@ -748,8 +751,6 @@ static int __devinit tc35815_init_one (struct pci_dev *pdev,
         dev->irq = pdev->irq;
         dev->base_addr = (unsigned long) ioaddr;
 
-        /* dev->priv/lp zeroed and aligned in alloc_etherdev */
-        lp = dev->priv;
         spin_lock_init(&lp->lock);
         lp->pci_dev = pdev;
         lp->boardtype = ent->driver_data;
@@ -1237,6 +1238,10 @@ tc35815_open(struct net_device *dev)
                 return -EAGAIN;
         }
 
+#ifdef TC35815_NAPI
+        napi_enable(&lp->napi);
+#endif
+
         /* Reset the hardware here. Don't forget to set the station address. */
         spin_lock_irq(&lp->lock);
         tc35815_chip_init(dev);
@@ -1436,6 +1441,7 @@ static int tc35815_do_interrupt(struct net_device *dev, u32 status)
 static irqreturn_t tc35815_interrupt(int irq, void *dev_id)
 {
         struct net_device *dev = dev_id;
+        struct tc35815_local *lp = netdev_priv(dev);
         struct tc35815_regs __iomem *tr =
                 (struct tc35815_regs __iomem *)dev->base_addr;
 #ifdef TC35815_NAPI
@@ -1444,8 +1450,8 @@ static irqreturn_t tc35815_interrupt(int irq, void *dev_id)
         if (!(dmactl & DMA_IntMask)) {
                 /* disable interrupts */
                 tc_writel(dmactl | DMA_IntMask, &tr->DMA_Ctl);
-                if (netif_rx_schedule_prep(dev))
-                        __netif_rx_schedule(dev);
+                if (netif_rx_schedule_prep(dev, &lp->napi))
+                        __netif_rx_schedule(dev, &lp->napi);
                 else {
                         printk(KERN_ERR "%s: interrupt taken in poll\n",
                                dev->name);
@@ -1726,13 +1732,12 @@ tc35815_rx(struct net_device *dev)
 }
 
 #ifdef TC35815_NAPI
-static int
-tc35815_poll(struct net_device *dev, int *budget)
+static int tc35815_poll(struct napi_struct *napi, int budget)
 {
-        struct tc35815_local *lp = dev->priv;
+        struct tc35815_local *lp = container_of(napi, struct tc35815_local, napi);
+        struct net_device *dev = lp->dev;
         struct tc35815_regs __iomem *tr =
                 (struct tc35815_regs __iomem *)dev->base_addr;
-        int limit = min(*budget, dev->quota);
         int received = 0, handled;
         u32 status;
 
@@ -1744,23 +1749,19 @@ tc35815_poll(struct net_device *dev, int *budget)
                 handled = tc35815_do_interrupt(dev, status, limit);
                 if (handled >= 0) {
                         received += handled;
-                        limit -= handled;
-                        if (limit <= 0)
+                        if (received >= budget)
                                 break;
                 }
                 status = tc_readl(&tr->Int_Src);
         } while (status);
         spin_unlock(&lp->lock);
 
-        dev->quota -= received;
-        *budget -= received;
-        if (limit <= 0)
-                return 1;
-
-        netif_rx_complete(dev);
-        /* enable interrupts */
-        tc_writel(tc_readl(&tr->DMA_Ctl) & ~DMA_IntMask, &tr->DMA_Ctl);
-        return 0;
+        if (received < budget) {
+                netif_rx_complete(dev, napi);
+                /* enable interrupts */
+                tc_writel(tc_readl(&tr->DMA_Ctl) & ~DMA_IntMask, &tr->DMA_Ctl);
+        }
+        return received;
 }
 #endif
 
@@ -1949,7 +1950,11 @@ static int
 tc35815_close(struct net_device *dev)
 {
         struct tc35815_local *lp = dev->priv;
+
         netif_stop_queue(dev);
+#ifdef TC35815_NAPI
+        napi_disable(&lp->napi);
+#endif
 
         /* Flush the Tx and disable Rx here. */