[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, 41 insertions, 53 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index ea117fc3d5e3..a0d75b0f3798 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -1130,7 +1130,7 @@ static void sky2_vlan_rx_register(struct net_device *dev, struct vlan_group *grp
 	u16 port = sky2->port;
 
 	netif_tx_lock_bh(dev);
-	netif_poll_disable(sky2->hw->dev[0]);
+	napi_disable(&hw->napi);
 
 	sky2->vlgrp = grp;
 	if (grp) {
@@ -1145,7 +1145,7 @@ static void sky2_vlan_rx_register(struct net_device *dev, struct vlan_group *grp
 			     TX_VLAN_TAG_OFF);
 	}
 
-	netif_poll_enable(sky2->hw->dev[0]);
+	napi_enable(&hw->napi);
 	netif_tx_unlock_bh(dev);
 }
 #endif
@@ -1385,9 +1385,13 @@ static int sky2_up(struct net_device *dev)
 	sky2_prefetch_init(hw, txqaddr[port], sky2->tx_le_map,
 			   TX_RING_SIZE - 1);
 
+	napi_enable(&hw->napi);
+
 	err = sky2_rx_start(sky2);
-	if (err)
+	if (err) {
+		napi_disable(&hw->napi);
 		goto err_out;
+	}
 
 	/* Enable interrupts from phy/mac for port */
 	imask = sky2_read32(hw, B0_IMSK);
@@ -1676,6 +1680,8 @@ static int sky2_down(struct net_device *dev)
 	/* Stop more packets from being queued */
 	netif_stop_queue(dev);
 
+	napi_disable(&hw->napi);
+
 	/* Disable port IRQ */
 	imask = sky2_read32(hw, B0_IMSK);
 	imask &= ~portirq_msk[port];
@@ -2016,7 +2022,7 @@ static int sky2_change_mtu(struct net_device *dev, int new_mtu)
 
 	dev->trans_start = jiffies;	/* prevent tx timeout */
 	netif_stop_queue(dev);
-	netif_poll_disable(hw->dev[0]);
+	napi_disable(&hw->napi);
 
 	synchronize_irq(hw->pdev->irq);
 
@@ -2043,12 +2049,16 @@ static int sky2_change_mtu(struct net_device *dev, int new_mtu)
 	err = sky2_rx_start(sky2);
 	sky2_write32(hw, B0_IMSK, imask);
 
+	/* Unconditionally re-enable NAPI because even if we
+	 * call dev_close() that will do a napi_disable().
+	 */
+	napi_enable(&hw->napi);
+
 	if (err)
 		dev_close(dev);
 	else {
 		gma_write16(hw, port, GM_GP_CTRL, ctl);
 
-		netif_poll_enable(hw->dev[0]);
 		netif_wake_queue(dev);
 	}
 
@@ -2544,18 +2554,15 @@ static int sky2_rx_hung(struct net_device *dev)
 static void sky2_watchdog(unsigned long arg)
 {
 	struct sky2_hw *hw = (struct sky2_hw *) arg;
-	struct net_device *dev;
 
 	/* Check for lost IRQ once a second */
 	if (sky2_read32(hw, B0_ISRC)) {
-		dev = hw->dev[0];
-		if (__netif_rx_schedule_prep(dev))
-			__netif_rx_schedule(dev);
+		napi_schedule(&hw->napi);
 	} else {
 		int i, active = 0;
 
 		for (i = 0; i < hw->ports; i++) {
-			dev = hw->dev[i];
+			struct net_device *dev = hw->dev[i];
 			if (!netif_running(dev))
 				continue;
 			++active;
@@ -2605,11 +2612,11 @@ static void sky2_err_intr(struct sky2_hw *hw, u32 status)
 		sky2_le_error(hw, 1, Q_XA2, TX_RING_SIZE);
 }
 
-static int sky2_poll(struct net_device *dev0, int *budget)
+static int sky2_poll(struct napi_struct *napi, int work_limit)
 {
-	struct sky2_hw *hw = ((struct sky2_port *) netdev_priv(dev0))->hw;
-	int work_done;
+	struct sky2_hw *hw = container_of(napi, struct sky2_hw, napi);
 	u32 status = sky2_read32(hw, B0_Y2_SP_EISR);
+	int work_done;
 
 	if (unlikely(status & Y2_IS_ERROR))
 		sky2_err_intr(hw, status);
@@ -2620,31 +2627,27 @@ static int sky2_poll(struct net_device *dev0, int *budget)
 	if (status & Y2_IS_IRQ_PHY2)
 		sky2_phy_intr(hw, 1);
 
-	work_done = sky2_status_intr(hw, min(dev0->quota, *budget));
-	*budget -= work_done;
-	dev0->quota -= work_done;
+	work_done = sky2_status_intr(hw, work_limit);
 
 	/* More work? */
- 	if (hw->st_idx != sky2_read16(hw, STAT_PUT_IDX))
-		return 1;
+	if (hw->st_idx == sky2_read16(hw, STAT_PUT_IDX)) {
+		/* Bug/Errata workaround?
+		 * Need to kick the TX irq moderation timer.
+		 */
+		if (sky2_read8(hw, STAT_TX_TIMER_CTRL) == TIM_START) {
+			sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_STOP);
+			sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_START);
+		}
 
-	/* Bug/Errata workaround?
-	 * Need to kick the TX irq moderation timer.
-	 */
-	if (sky2_read8(hw, STAT_TX_TIMER_CTRL) == TIM_START) {
-		sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_STOP);
-		sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_START);
+		napi_complete(napi);
+		sky2_read32(hw, B0_Y2_SP_LISR);
 	}
-	netif_rx_complete(dev0);
-
-	sky2_read32(hw, B0_Y2_SP_LISR);
-	return 0;
+	return work_done;
 }
 
 static irqreturn_t sky2_intr(int irq, void *dev_id)
 {
 	struct sky2_hw *hw = dev_id;
-	struct net_device *dev0 = hw->dev[0];
 	u32 status;
 
 	/* Reading this mask interrupts as side effect */
@@ -2653,8 +2656,8 @@ static irqreturn_t sky2_intr(int irq, void *dev_id)
 		return IRQ_NONE;
 
 	prefetch(&hw->st_le[hw->st_idx]);
-	if (likely(__netif_rx_schedule_prep(dev0)))
-		__netif_rx_schedule(dev0);
+
+	napi_schedule(&hw->napi);
 
 	return IRQ_HANDLED;
 }
@@ -2663,10 +2666,8 @@ static irqreturn_t sky2_intr(int irq, void *dev_id)
 static void sky2_netpoll(struct net_device *dev)
 {
 	struct sky2_port *sky2 = netdev_priv(dev);
-	struct net_device *dev0 = sky2->hw->dev[0];
 
-	if (netif_running(dev) && __netif_rx_schedule_prep(dev0))
-		__netif_rx_schedule(dev0);
+	napi_schedule(&sky2->hw->napi);
 }
 #endif
 
@@ -2914,8 +2915,6 @@ static void sky2_restart(struct work_struct *work)
 	sky2_write32(hw, B0_IMSK, 0);
 	sky2_read32(hw, B0_IMSK);
 
-	netif_poll_disable(hw->dev[0]);
-
 	for (i = 0; i < hw->ports; i++) {
 		dev = hw->dev[i];
 		if (netif_running(dev))
@@ -2924,7 +2923,6 @@ static void sky2_restart(struct work_struct *work)
 
 	sky2_reset(hw);
 	sky2_write32(hw, B0_IMSK, Y2_IS_BASE);
-	netif_poll_enable(hw->dev[0]);
 
 	for (i = 0; i < hw->ports; i++) {
 		dev = hw->dev[i];
@@ -3735,7 +3733,7 @@ static int sky2_debug_show(struct seq_file *seq, void *v)
 {
 	struct net_device *dev = seq->private;
 	const struct sky2_port *sky2 = netdev_priv(dev);
-	const struct sky2_hw *hw = sky2->hw;
+	struct sky2_hw *hw = sky2->hw;
 	unsigned port = sky2->port;
 	unsigned idx, last;
 	int sop;
@@ -3748,7 +3746,7 @@ static int sky2_debug_show(struct seq_file *seq, void *v)
 		   sky2_read32(hw, B0_IMSK),
 		   sky2_read32(hw, B0_Y2_SP_ICR));
 
-	netif_poll_disable(hw->dev[0]);
+	napi_disable(&hw->napi);
 	last = sky2_read16(hw, STAT_PUT_IDX);
 
 	if (hw->st_idx == last)
@@ -3818,7 +3816,7 @@ static int sky2_debug_show(struct seq_file *seq, void *v)
 		   last = sky2_read16(hw, Y2_QADDR(rxqaddr[port], PREF_UNIT_PUT_IDX)),
 		   sky2_read16(hw, Y2_QADDR(rxqaddr[port], PREF_UNIT_LAST_IDX)));
 
-	netif_poll_enable(hw->dev[0]);
+	napi_enable(&hw->napi);
 	return 0;
 }
 
@@ -3943,15 +3941,8 @@ static __devinit struct net_device *sky2_init_netdev(struct sky2_hw *hw,
 	SET_ETHTOOL_OPS(dev, &sky2_ethtool_ops);
 	dev->tx_timeout = sky2_tx_timeout;
 	dev->watchdog_timeo = TX_WATCHDOG;
-	if (port == 0)
-		dev->poll = sky2_poll;
-	dev->weight = NAPI_WEIGHT;
 #ifdef CONFIG_NET_POLL_CONTROLLER
-	/* Network console (only works on port 0)
-	 * because netpoll makes assumptions about NAPI
-	 */
-	if (port == 0)
-		dev->poll_controller = sky2_netpoll;
+	dev->poll_controller = sky2_netpoll;
 #endif
 
 	sky2 = netdev_priv(dev);
@@ -4166,6 +4157,7 @@ static int __devinit sky2_probe(struct pci_dev *pdev,
 		err = -ENOMEM;
 		goto err_out_free_pci;
 	}
+	netif_napi_add(dev, &hw->napi, sky2_poll, NAPI_WEIGHT);
 
 	if (!disable_msi && pci_enable_msi(pdev) == 0) {
 		err = sky2_test_msi(hw);
@@ -4288,8 +4280,6 @@ static int sky2_suspend(struct pci_dev *pdev, pm_message_t state)
 	if (!hw)
 		return 0;
 
-	netif_poll_disable(hw->dev[0]);
-
 	for (i = 0; i < hw->ports; i++) {
 		struct net_device *dev = hw->dev[i];
 		struct sky2_port *sky2 = netdev_priv(dev);
@@ -4356,8 +4346,6 @@ static int sky2_resume(struct pci_dev *pdev)
 		}
 	}
 
-	netif_poll_enable(hw->dev[0]);
-
 	return 0;
 out:
 	dev_err(&pdev->dev, "resume failed (%d)\n", err);
@@ -4374,7 +4362,7 @@ static void sky2_shutdown(struct pci_dev *pdev)
 	if (!hw)
 		return;
 
-	netif_poll_disable(hw->dev[0]);
+	napi_disable(&hw->napi);
 
 	for (i = 0; i < hw->ports; i++) {
 		struct net_device *dev = hw->dev[i];