net: introduce iterators over synced hw addresses

Some network drivers use __dev_mc_sync()/__dev_uc_sync() and therefore
program the hardware only with addresses with a non-zero sync_cnt.

Some of the above drivers also need to save/restore the address
filtering lists when certain events happen, and they need to walk
through the struct net_device :: uc and struct net_device :: mc lists.
But these lists contain unsynced addresses too.

To keep the appearance of an elementary form of data encapsulation,
provide iterators through these lists that only look at entries with a
non-zero sync_cnt, instead of filtering entries out from device drivers.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

include/linux/netdevice.h

@@ -253,11 +253,17 @@ struct netdev_hw_addr_list {
 #define netdev_uc_empty(dev) netdev_hw_addr_list_empty(&(dev)->uc)
 #define netdev_for_each_uc_addr(ha, dev) \
 	netdev_hw_addr_list_for_each(ha, &(dev)->uc)
+#define netdev_for_each_synced_uc_addr(_ha, _dev) \
+	netdev_for_each_uc_addr((_ha), (_dev)) \
+		if ((_ha)->sync_cnt)
 
 #define netdev_mc_count(dev) netdev_hw_addr_list_count(&(dev)->mc)
 #define netdev_mc_empty(dev) netdev_hw_addr_list_empty(&(dev)->mc)
 #define netdev_for_each_mc_addr(ha, dev) \
 	netdev_hw_addr_list_for_each(ha, &(dev)->mc)
+#define netdev_for_each_synced_mc_addr(_ha, _dev) \
+	netdev_for_each_mc_addr((_ha), (_dev)) \
+		if ((_ha)->sync_cnt)
 
 struct hh_cache {
 	unsigned int	hh_len;