arc_emac: implement promiscuous mode and multicast filtering

This patch implements the set_rx_mode function to enable/disable
promiscuous or all-multicast modes and to update the multicast
filtering list of the device.
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/arc/emac_main.c

@@ -13,6 +13,7 @@
  *		Vineet Gupta
  */
 
+#include <linux/crc32.h>
 #include <linux/etherdevice.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -450,6 +451,41 @@ static int arc_emac_open(struct net_device *ndev)
 	return 0;
 }
 
+/**
+ * arc_emac_set_rx_mode - Change the receive filtering mode.
+ * @ndev:	Pointer to the network device.
+ *
+ * This function enables/disables promiscuous or all-multicast mode
+ * and updates the multicast filtering list of the network device.
+ */
+static void arc_emac_set_rx_mode(struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+
+	if (ndev->flags & IFF_PROMISC) {
+		arc_reg_or(priv, R_CTRL, PROM_MASK);
+	} else {
+		arc_reg_clr(priv, R_CTRL, PROM_MASK);
+
+		if (ndev->flags & IFF_ALLMULTI) {
+			arc_reg_set(priv, R_LAFL, ~0);
+			arc_reg_set(priv, R_LAFH, ~0);
+		} else {
+			struct netdev_hw_addr *ha;
+			unsigned int filter[2] = { 0, 0 };
+			int bit;
+
+			netdev_for_each_mc_addr(ha, ndev) {
+				bit = ether_crc_le(ETH_ALEN, ha->addr) >> 26;
+				filter[bit >> 5] |= 1 << (bit & 31);
+			}
+
+			arc_reg_set(priv, R_LAFL, filter[0]);
+			arc_reg_set(priv, R_LAFH, filter[1]);
+		}
+	}
+}
+
 /**
  * arc_emac_stop - Close the network device.
  * @ndev:	Pointer to the network device.
@@ -620,6 +656,7 @@ static const struct net_device_ops arc_emac_netdev_ops = {
 	.ndo_start_xmit		= arc_emac_tx,
 	.ndo_set_mac_address	= arc_emac_set_address,
 	.ndo_get_stats		= arc_emac_stats,
+	.ndo_set_rx_mode	= arc_emac_set_rx_mode,
 };
 
 static int arc_emac_probe(struct platform_device *pdev)