[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, 21 insertions, 27 deletions

diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index 315335671f0f..702eba549161 100644
--- a/drivers/net/mv643xx_eth.c
+++ b/drivers/net/mv643xx_eth.c
@@ -66,7 +66,7 @@ static int mv643xx_eth_change_mtu(struct net_device *, int);
 static struct net_device_stats *mv643xx_eth_get_stats(struct net_device *);
 static void eth_port_init_mac_tables(unsigned int eth_port_num);
 #ifdef MV643XX_NAPI
-static int mv643xx_poll(struct net_device *dev, int *budget);
+static int mv643xx_poll(struct napi_struct *napi, int budget);
 #endif
 static int ethernet_phy_get(unsigned int eth_port_num);
 static void ethernet_phy_set(unsigned int eth_port_num, int phy_addr);
@@ -562,7 +562,7 @@ static irqreturn_t mv643xx_eth_int_handler(int irq, void *dev_id)
                 /* wait for previous write to complete */
                 mv_read(MV643XX_ETH_INTERRUPT_MASK_REG(port_num));
 
-                netif_rx_schedule(dev);
+                netif_rx_schedule(dev, &mp->napi);
         }
 #else
         if (eth_int_cause & ETH_INT_CAUSE_RX)
@@ -880,6 +880,10 @@ static int mv643xx_eth_open(struct net_device *dev)
 
         mv643xx_eth_rx_refill_descs(dev);       /* Fill RX ring with skb's */
 
+#ifdef MV643XX_NAPI
+        napi_enable(&mp->napi);
+#endif
+
         eth_port_start(dev);
 
         /* Interrupt Coalescing */
@@ -982,7 +986,7 @@ static int mv643xx_eth_stop(struct net_device *dev)
         mv_read(MV643XX_ETH_INTERRUPT_MASK_REG(port_num));
 
 #ifdef MV643XX_NAPI
-        netif_poll_disable(dev);
+        napi_disable(&mp->napi);
 #endif
         netif_carrier_off(dev);
         netif_stop_queue(dev);
@@ -992,10 +996,6 @@ static int mv643xx_eth_stop(struct net_device *dev)
         mv643xx_eth_free_tx_rings(dev);
         mv643xx_eth_free_rx_rings(dev);
 
-#ifdef MV643XX_NAPI
-        netif_poll_enable(dev);
-#endif
-
         free_irq(dev->irq, dev);
 
         return 0;
@@ -1007,11 +1007,12 @@ static int mv643xx_eth_stop(struct net_device *dev)
  *
  * This function is used in case of NAPI
  */
-static int mv643xx_poll(struct net_device *dev, int *budget)
+static int mv643xx_poll(struct napi_struct *napi, int budget)
 {
-        struct mv643xx_private *mp = netdev_priv(dev);
-        int done = 1, orig_budget, work_done;
+        struct mv643xx_private *mp = container_of(napi, struct mv643xx_private, napi);
+        struct net_device *dev = mp->dev;
         unsigned int port_num = mp->port_num;
+        int work_done;
 
 #ifdef MV643XX_TX_FAST_REFILL
         if (++mp->tx_clean_threshold > 5) {
@@ -1020,27 +1021,20 @@ static int mv643xx_poll(struct net_device *dev, int *budget)
         }
 #endif
 
+        work_done = 0;
         if ((mv_read(MV643XX_ETH_RX_CURRENT_QUEUE_DESC_PTR_0(port_num)))
-                                                != (u32) mp->rx_used_desc_q) {
-                orig_budget = *budget;
-                if (orig_budget > dev->quota)
-                        orig_budget = dev->quota;
-                work_done = mv643xx_eth_receive_queue(dev, orig_budget);
-                *budget -= work_done;
-                dev->quota -= work_done;
-                if (work_done >= orig_budget)
-                        done = 0;
-        }
+            != (u32) mp->rx_used_desc_q)
+                work_done = mv643xx_eth_receive_queue(dev, budget);
 
-        if (done) {
-                netif_rx_complete(dev);
+        if (work_done < budget) {
+                netif_rx_complete(dev, napi);
                 mv_write(MV643XX_ETH_INTERRUPT_CAUSE_REG(port_num), 0);
                 mv_write(MV643XX_ETH_INTERRUPT_CAUSE_EXTEND_REG(port_num), 0);
                 mv_write(MV643XX_ETH_INTERRUPT_MASK_REG(port_num),
                                                 ETH_INT_UNMASK_ALL);
         }
 
-        return done ? 0 : 1;
+        return work_done;
 }
 #endif
 
@@ -1333,6 +1327,10 @@ static int mv643xx_eth_probe(struct platform_device *pdev)
         platform_set_drvdata(pdev, dev);
 
         mp = netdev_priv(dev);
+        mp->dev = dev;
+#ifdef MV643XX_NAPI
+        netif_napi_add(dev, &mp->napi, mv643xx_poll, 64);
+#endif
 
         res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
         BUG_ON(!res);
@@ -1347,10 +1345,6 @@ static int mv643xx_eth_probe(struct platform_device *pdev)
 
         /* No need to Tx Timeout */
         dev->tx_timeout = mv643xx_eth_tx_timeout;
-#ifdef MV643XX_NAPI
-        dev->poll = mv643xx_poll;
-        dev->weight = 64;
-#endif
 
 #ifdef CONFIG_NET_POLL_CONTROLLER
         dev->poll_controller = mv643xx_netpoll;