[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, 33 insertions, 31 deletions

diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c
index 9a38dfe45f8f..72f617bf2520 100644
--- a/drivers/net/ucc_geth.c
+++ b/drivers/net/ucc_geth.c
@@ -3582,41 +3582,31 @@ static int ucc_geth_tx(struct net_device *dev, u8 txQ)
 }
 
 #ifdef CONFIG_UGETH_NAPI
-static int ucc_geth_poll(struct net_device *dev, int *budget)
+static int ucc_geth_poll(struct napi_struct *napi, int budget)
 {
-	struct ucc_geth_private *ugeth = netdev_priv(dev);
+	struct ucc_geth_private *ugeth = container_of(napi, struct ucc_geth_private, napi);
+	struct net_device *dev = ugeth->dev;
 	struct ucc_geth_info *ug_info;
-	struct ucc_fast_private *uccf;
-	int howmany;
-	u8 i;
-	int rx_work_limit;
-	register u32 uccm;
+	int howmany, i;
 
 	ug_info = ugeth->ug_info;
 
-	rx_work_limit = *budget;
-	if (rx_work_limit > dev->quota)
-		rx_work_limit = dev->quota;
-
 	howmany = 0;
+	for (i = 0; i < ug_info->numQueuesRx; i++)
+		howmany += ucc_geth_rx(ugeth, i, budget - howmany);
 
-	for (i = 0; i < ug_info->numQueuesRx; i++) {
-		howmany += ucc_geth_rx(ugeth, i, rx_work_limit);
-	}
-
-	dev->quota -= howmany;
-	rx_work_limit -= howmany;
-	*budget -= howmany;
+	if (howmany < budget) {
+		struct ucc_fast_private *uccf;
+		u32 uccm;
 
-	if (rx_work_limit > 0) {
-		netif_rx_complete(dev);
+		netif_rx_complete(dev, napi);
 		uccf = ugeth->uccf;
 		uccm = in_be32(uccf->p_uccm);
 		uccm |= UCCE_RX_EVENTS;
 		out_be32(uccf->p_uccm, uccm);
 	}
 
-	return (rx_work_limit > 0) ? 0 : 1;
+	return howmany;
 }
 #endif				/* CONFIG_UGETH_NAPI */
 
@@ -3651,10 +3641,10 @@ static irqreturn_t ucc_geth_irq_handler(int irq, void *info)
 	/* check for receive events that require processing */
 	if (ucce & UCCE_RX_EVENTS) {
 #ifdef CONFIG_UGETH_NAPI
-		if (netif_rx_schedule_prep(dev)) {
-		uccm &= ~UCCE_RX_EVENTS;
+		if (netif_rx_schedule_prep(dev, &ugeth->napi)) {
+			uccm &= ~UCCE_RX_EVENTS;
 			out_be32(uccf->p_uccm, uccm);
-			__netif_rx_schedule(dev);
+			__netif_rx_schedule(dev, &ugeth->napi);
 		}
 #else
 		rx_mask = UCCE_RXBF_SINGLE_MASK;
@@ -3717,12 +3707,15 @@ static int ucc_geth_open(struct net_device *dev)
 		return err;
 	}
 
+#ifdef CONFIG_UGETH_NAPI
+	napi_enable(&ugeth->napi);
+#endif
 	err = ucc_geth_startup(ugeth);
 	if (err) {
 		if (netif_msg_ifup(ugeth))
 			ugeth_err("%s: Cannot configure net device, aborting.",
 				  dev->name);
-		return err;
+		goto out_err;
 	}
 
 	err = adjust_enet_interface(ugeth);
@@ -3730,7 +3723,7 @@ static int ucc_geth_open(struct net_device *dev)
 		if (netif_msg_ifup(ugeth))
 			ugeth_err("%s: Cannot configure net device, aborting.",
 				  dev->name);
-		return err;
+		goto out_err;
 	}
 
 	/*       Set MACSTNADDR1, MACSTNADDR2                */
@@ -3748,7 +3741,7 @@ static int ucc_geth_open(struct net_device *dev)
 	if (err) {
 		if (netif_msg_ifup(ugeth))
 			ugeth_err("%s: Cannot initialize PHY, aborting.", dev->name);
-		return err;
+		goto out_err;
 	}
 
 	phy_start(ugeth->phydev);
@@ -3761,7 +3754,7 @@ static int ucc_geth_open(struct net_device *dev)
 			ugeth_err("%s: Cannot get IRQ for net device, aborting.",
 				  dev->name);
 		ucc_geth_stop(ugeth);
-		return err;
+		goto out_err;
 	}
 
 	err = ugeth_enable(ugeth, COMM_DIR_RX_AND_TX);
@@ -3769,12 +3762,18 @@ static int ucc_geth_open(struct net_device *dev)
 		if (netif_msg_ifup(ugeth))
 			ugeth_err("%s: Cannot enable net device, aborting.", dev->name);
 		ucc_geth_stop(ugeth);
-		return err;
+		goto out_err;
 	}
 
 	netif_start_queue(dev);
 
 	return err;
+
+out_err:
+#ifdef CONFIG_UGETH_NAPI
+	napi_disable(&ugeth->napi);
+#endif
+	return err;
 }
 
 /* Stops the kernel queue, and halts the controller */
@@ -3784,6 +3783,10 @@ static int ucc_geth_close(struct net_device *dev)
 
 	ugeth_vdbg("%s: IN", __FUNCTION__);
 
+#ifdef CONFIG_UGETH_NAPI
+	napi_disable(&ugeth->napi);
+#endif
+
 	ucc_geth_stop(ugeth);
 
 	phy_disconnect(ugeth->phydev);
@@ -3964,8 +3967,7 @@ static int ucc_geth_probe(struct of_device* ofdev, const struct of_device_id *ma
 	dev->tx_timeout = ucc_geth_timeout;
 	dev->watchdog_timeo = TX_TIMEOUT;
 #ifdef CONFIG_UGETH_NAPI
-	dev->poll = ucc_geth_poll;
-	dev->weight = UCC_GETH_DEV_WEIGHT;
+	netif_napi_add(dev, &ugeth->napi, ucc_geth_poll, UCC_GETH_DEV_WEIGHT);
 #endif				/* CONFIG_UGETH_NAPI */
 	dev->stop = ucc_geth_close;
 	dev->get_stats = ucc_geth_get_stats;