[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, 32 insertions, 26 deletions

diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
index c76dd29c8e9a..3f2306e3f517 100644
--- a/drivers/net/r8169.c
+++ b/drivers/net/r8169.c
@@ -384,6 +384,7 @@ struct rtl8169_private {
         void __iomem *mmio_addr;        /* memory map physical address */
         struct pci_dev *pci_dev;        /* Index of PCI device */
         struct net_device *dev;
+        struct napi_struct napi;
         struct net_device_stats stats;  /* statistics of net device */
         spinlock_t lock;                /* spin lock flag */
         u32 msg_enable;
@@ -443,13 +444,13 @@ static void rtl_set_rx_mode(struct net_device *dev);
 static void rtl8169_tx_timeout(struct net_device *dev);
 static struct net_device_stats *rtl8169_get_stats(struct net_device *dev);
 static int rtl8169_rx_interrupt(struct net_device *, struct rtl8169_private *,
-                                void __iomem *);
+                                void __iomem *, u32 budget);
 static int rtl8169_change_mtu(struct net_device *dev, int new_mtu);
 static void rtl8169_down(struct net_device *dev);
 static void rtl8169_rx_clear(struct rtl8169_private *tp);
 
 #ifdef CONFIG_R8169_NAPI
-static int rtl8169_poll(struct net_device *dev, int *budget);
+static int rtl8169_poll(struct napi_struct *napi, int budget);
 #endif
 
 static const unsigned int rtl8169_rx_config =
@@ -1656,8 +1657,7 @@ rtl8169_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
         dev->set_mac_address = rtl_set_mac_address;
 
 #ifdef CONFIG_R8169_NAPI
-        dev->poll = rtl8169_poll;
-        dev->weight = R8169_NAPI_WEIGHT;
+        netif_napi_add(dev, &tp->napi, rtl8169_poll, R8169_NAPI_WEIGHT);
 #endif
 
 #ifdef CONFIG_R8169_VLAN
@@ -1777,6 +1777,10 @@ static int rtl8169_open(struct net_device *dev)
         if (retval < 0)
                 goto err_release_ring_2;
 
+#ifdef CONFIG_R8169_NAPI
+        napi_enable(&tp->napi);
+#endif
+
         rtl_hw_start(dev);
 
         rtl8169_request_timer(dev);
@@ -2082,7 +2086,9 @@ static int rtl8169_change_mtu(struct net_device *dev, int new_mtu)
         if (ret < 0)
                 goto out;
 
-        netif_poll_enable(dev);
+#ifdef CONFIG_R8169_NAPI
+        napi_enable(&tp->napi);
+#endif
 
         rtl_hw_start(dev);
 
@@ -2274,11 +2280,15 @@ static void rtl8169_wait_for_quiescence(struct net_device *dev)
         synchronize_irq(dev->irq);
 
         /* Wait for any pending NAPI task to complete */
-        netif_poll_disable(dev);
+#ifdef CONFIG_R8169_NAPI
+        napi_disable(&tp->napi);
+#endif
 
         rtl8169_irq_mask_and_ack(ioaddr);
 
-        netif_poll_enable(dev);
+#ifdef CONFIG_R8169_NAPI
+        napi_enable(&tp->napi);
+#endif
 }
 
 static void rtl8169_reinit_task(struct work_struct *work)
@@ -2322,7 +2332,7 @@ static void rtl8169_reset_task(struct work_struct *work)
 
         rtl8169_wait_for_quiescence(dev);
 
-        rtl8169_rx_interrupt(dev, tp, tp->mmio_addr);
+        rtl8169_rx_interrupt(dev, tp, tp->mmio_addr, ~(u32)0);
         rtl8169_tx_clear(tp);
 
         if (tp->dirty_rx == tp->cur_rx) {
@@ -2636,14 +2646,14 @@ out:
 
 static int rtl8169_rx_interrupt(struct net_device *dev,
                                 struct rtl8169_private *tp,
-                                void __iomem *ioaddr)
+                                void __iomem *ioaddr, u32 budget)
 {
         unsigned int cur_rx, rx_left;
         unsigned int delta, count;
 
         cur_rx = tp->cur_rx;
         rx_left = NUM_RX_DESC + tp->dirty_rx - cur_rx;
-        rx_left = rtl8169_rx_quota(rx_left, (u32) dev->quota);
+        rx_left = rtl8169_rx_quota(rx_left, budget);
 
         for (; rx_left > 0; rx_left--, cur_rx++) {
                 unsigned int entry = cur_rx % NUM_RX_DESC;
@@ -2792,8 +2802,8 @@ static irqreturn_t rtl8169_interrupt(int irq, void *dev_instance)
                         RTL_W16(IntrMask, tp->intr_event & ~tp->napi_event);
                         tp->intr_mask = ~tp->napi_event;
 
-                        if (likely(netif_rx_schedule_prep(dev)))
-                                __netif_rx_schedule(dev);
+                if (likely(netif_rx_schedule_prep(dev, &tp->napi)))
+                        __netif_rx_schedule(dev, &tp->napi);
                         else if (netif_msg_intr(tp)) {
                                 printk(KERN_INFO "%s: interrupt %04x in poll\n",
                                        dev->name, status);
@@ -2803,7 +2813,7 @@ static irqreturn_t rtl8169_interrupt(int irq, void *dev_instance)
 #else
                 /* Rx interrupt */
                 if (status & (RxOK | RxOverflow | RxFIFOOver))
-                        rtl8169_rx_interrupt(dev, tp, ioaddr);
+                        rtl8169_rx_interrupt(dev, tp, ioaddr, ~(u32)0);
 
                 /* Tx interrupt */
                 if (status & (TxOK | TxErr))
@@ -2826,20 +2836,18 @@ out:
 }
 
 #ifdef CONFIG_R8169_NAPI
-static int rtl8169_poll(struct net_device *dev, int *budget)
+static int rtl8169_poll(struct napi_struct *napi, int budget)
 {
-        unsigned int work_done, work_to_do = min(*budget, dev->quota);
-        struct rtl8169_private *tp = netdev_priv(dev);
+        struct rtl8169_private *tp = container_of(napi, struct rtl8169_private, napi);
+        struct net_device *dev = tp->dev;
         void __iomem *ioaddr = tp->mmio_addr;
+        int work_done;
 
-        work_done = rtl8169_rx_interrupt(dev, tp, ioaddr);
+        work_done = rtl8169_rx_interrupt(dev, tp, ioaddr, (u32) budget);
         rtl8169_tx_interrupt(dev, tp, ioaddr);
 
-        *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);
                 tp->intr_mask = 0xffff;
                 /*
                  * 20040426: the barrier is not strictly required but the
@@ -2851,7 +2859,7 @@ static int rtl8169_poll(struct net_device *dev, int *budget)
                 RTL_W16(IntrMask, tp->intr_event);
         }
 
-        return (work_done >= work_to_do);
+        return work_done;
 }
 #endif
 
@@ -2880,7 +2888,7 @@ core_down:
         synchronize_irq(dev->irq);
 
         if (!poll_locked) {
-                netif_poll_disable(dev);
+                napi_disable(&tp->napi);
                 poll_locked++;
         }
 
@@ -2918,8 +2926,6 @@ static int rtl8169_close(struct net_device *dev)
 
         free_irq(dev->irq, dev);
 
-        netif_poll_enable(dev);
-
         pci_free_consistent(pdev, R8169_RX_RING_BYTES, tp->RxDescArray,
                             tp->RxPhyAddr);
         pci_free_consistent(pdev, R8169_TX_RING_BYTES, tp->TxDescArray,