macb: Add support of the netpoll API

With this patch in place, I'm successfully able to use the netconsole
mechanism with the Calao USB-A9263 board, which uses the AT91SAM9263
CPU, which in terms of Ethernet controller is supported by the macb
driver.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
[haavard.skinnemoen@atmel.com: disable_irq() -> local_irq_save()]
[haavard.skinnemoen@atmel.com: convert to net_device_ops]
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/macb.c

@@ -599,6 +599,21 @@ static irqreturn_t macb_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+/*
+ * Polling receive - used by netconsole and other diagnostic tools
+ * to allow network i/o with interrupts disabled.
+ */
+static void macb_poll_controller(struct net_device *dev)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	macb_interrupt(dev->irq, dev);
+	local_irq_restore(flags);
+}
+#endif
+
 static int macb_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct macb *bp = netdev_priv(dev);
@@ -1094,6 +1109,9 @@ static const struct net_device_ops macb_netdev_ops = {
 	.ndo_validate_addr	= eth_validate_addr,
 	.ndo_change_mtu		= eth_change_mtu,
 	.ndo_set_mac_address	= eth_mac_addr,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	.ndo_poll_controller	= macb_poll_controller,
+#endif
 };
 
 static int __init macb_probe(struct platform_device *pdev)