[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, 20 insertions, 20 deletions

diff --git a/drivers/net/cassini.c b/drivers/net/cassini.c
index f6e4030c73d1..13f14df21e6e 100644
--- a/drivers/net/cassini.c
+++ b/drivers/net/cassini.c
@@ -2485,7 +2485,7 @@ static irqreturn_t cas_interruptN(int irq, void *dev_id)
         if (status & INTR_RX_DONE_ALT) { /* handle rx separately */
 #ifdef USE_NAPI
                 cas_mask_intr(cp);
-                netif_rx_schedule(dev);
+                netif_rx_schedule(dev, &cp->napi);
 #else
                 cas_rx_ringN(cp, ring, 0);
 #endif
@@ -2536,7 +2536,7 @@ static irqreturn_t cas_interrupt1(int irq, void *dev_id)
         if (status & INTR_RX_DONE_ALT) { /* handle rx separately */
 #ifdef USE_NAPI
                 cas_mask_intr(cp);
-                netif_rx_schedule(dev);
+                netif_rx_schedule(dev, &cp->napi);
 #else
                 cas_rx_ringN(cp, 1, 0);
 #endif
@@ -2592,7 +2592,7 @@ static irqreturn_t cas_interrupt(int irq, void *dev_id)
         if (status & INTR_RX_DONE) {
 #ifdef USE_NAPI
                 cas_mask_intr(cp);
-                netif_rx_schedule(dev);
+                netif_rx_schedule(dev, &cp->napi);
 #else
                 cas_rx_ringN(cp, 0, 0);
 #endif
@@ -2607,9 +2607,10 @@ static irqreturn_t cas_interrupt(int irq, void *dev_id)
 
 
 #ifdef USE_NAPI
-static int cas_poll(struct net_device *dev, int *budget)
+static int cas_poll(struct napi_struct *napi, int budget)
 {
-        struct cas *cp = netdev_priv(dev);
+        struct cas *cp = container_of(napi, struct cas, napi);
+        struct net_device *dev = cp->dev;
         int i, enable_intr, todo, credits;
         u32 status = readl(cp->regs + REG_INTR_STATUS);
         unsigned long flags;
@@ -2620,20 +2621,18 @@ static int cas_poll(struct net_device *dev, int *budget)
 
         /* NAPI rx packets. we spread the credits across all of the
          * rxc rings
-         */
-        todo = min(*budget, dev->quota);
-
-        /* to make sure we're fair with the work we loop through each
+         *
+         * to make sure we're fair with the work we loop through each
          * ring N_RX_COMP_RING times with a request of
-         * todo / N_RX_COMP_RINGS
+         * budget / N_RX_COMP_RINGS
          */
         enable_intr = 1;
         credits = 0;
         for (i = 0; i < N_RX_COMP_RINGS; i++) {
                 int j;
                 for (j = 0; j < N_RX_COMP_RINGS; j++) {
-                        credits += cas_rx_ringN(cp, j, todo / N_RX_COMP_RINGS);
-                        if (credits >= todo) {
+                        credits += cas_rx_ringN(cp, j, budget / N_RX_COMP_RINGS);
+                        if (credits >= budget) {
                                 enable_intr = 0;
                                 goto rx_comp;
                         }
@@ -2641,9 +2640,6 @@ static int cas_poll(struct net_device *dev, int *budget)
         }
 
 rx_comp:
-        *budget    -= credits;
-        dev->quota -= credits;
-
         /* final rx completion */
         spin_lock_irqsave(&cp->lock, flags);
         if (status)
@@ -2674,11 +2670,10 @@ rx_comp:
 #endif
         spin_unlock_irqrestore(&cp->lock, flags);
         if (enable_intr) {
-                netif_rx_complete(dev);
+                netif_rx_complete(dev, napi);
                 cas_unmask_intr(cp);
-                return 0;
         }
-        return 1;
+        return credits;
 }
 #endif
 
@@ -4351,6 +4346,9 @@ static int cas_open(struct net_device *dev)
                 goto err_spare;
         }
 
+#ifdef USE_NAPI
+        napi_enable(&cp->napi);
+#endif
         /* init hw */
         cas_lock_all_save(cp, flags);
         cas_clean_rings(cp);
@@ -4376,6 +4374,9 @@ static int cas_close(struct net_device *dev)
         unsigned long flags;
         struct cas *cp = netdev_priv(dev);
 
+#ifdef USE_NAPI
+        napi_enable(&cp->napi);
+#endif
         /* Make sure we don't get distracted by suspend/resume */
         mutex_lock(&cp->pm_mutex);
 
@@ -5062,8 +5063,7 @@ static int __devinit cas_init_one(struct pci_dev *pdev,
         dev->watchdog_timeo = CAS_TX_TIMEOUT;
         dev->change_mtu = cas_change_mtu;
 #ifdef USE_NAPI
-        dev->poll = cas_poll;
-        dev->weight = 64;
+        netif_napi_add(dev, &cp->napi, cas_poll, 64);
 #endif
 #ifdef CONFIG_NET_POLL_CONTROLLER
         dev->poll_controller = cas_netpoll;