sunvnet: track port queues correctly

Track our used and unused queue indexies correctly.  Otherwise, as ports
dropped out and returned, they all eventually ended up with the same
queue index.

Orabug: 25190537

Signed-off-by: Shannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/sun/sunvnet_common.c

@@ -1728,11 +1728,25 @@ EXPORT_SYMBOL_GPL(sunvnet_poll_controller_common);
 void sunvnet_port_add_txq_common(struct vnet_port *port)
 {
 	struct vnet *vp = port->vp;
-	int n;
+	int smallest = 0;
+	int i;
+
+	/* find the first least-used q
+	 * When there are more ldoms than q's, we start to
+	 * double up on ports per queue.
+	 */
+	for (i = 0; i < VNET_MAX_TXQS; i++) {
+		if (vp->q_used[i] == 0) {
+			smallest = i;
+			break;
+		}
+		if (vp->q_used[i] < vp->q_used[smallest])
+			smallest = i;
+	}
 
-	n = vp->nports++;
-	n = n & (VNET_MAX_TXQS - 1);
-	port->q_index = n;
+	vp->nports++;
+	vp->q_used[smallest]++;
+	port->q_index = smallest;
 	netif_tx_wake_queue(netdev_get_tx_queue(VNET_PORT_TO_NET_DEVICE(port),
 						port->q_index));
 }
@@ -1743,5 +1757,7 @@ void sunvnet_port_rm_txq_common(struct vnet_port *port)
 	port->vp->nports--;
 	netif_tx_stop_queue(netdev_get_tx_queue(VNET_PORT_TO_NET_DEVICE(port),
 						port->q_index));
+	port->vp->q_used[port->q_index]--;
+	port->q_index = 0;
 }
 EXPORT_SYMBOL_GPL(sunvnet_port_rm_txq_common);

drivers/net/ethernet/sun/sunvnet_common.h

@@ -112,22 +112,15 @@ struct vnet_mcast_entry {
 };
 
 struct vnet {
-	/* Protects port_list and port_hash.  */
-	spinlock_t		lock;
-
+	spinlock_t		lock; /* Protects port_list and port_hash.  */
 	struct net_device	*dev;
-
 	u32			msg_enable;
-
+	u8			q_used[VNET_MAX_TXQS];
 	struct list_head	port_list;
-
 	struct hlist_head	port_hash[VNET_PORT_HASH_SIZE];
-
 	struct vnet_mcast_entry	*mcast_list;
-
 	struct list_head	list;
 	u64			local_mac;
-
 	int			nports;
 };