net: systemport: Simplify queue mapping logic

The use of a bitmap speeds up the finding of the first available queue
to which we could start establishing the mapping for, but we still have
to loop over all slave network devices to set them up. Simplify the
logic to have a single loop, and use the fact that a correctly
configured ring has inspect set to true. This will make things simpler
to unwind during device unregistration.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bcmsysport.c

@@ -2324,7 +2324,7 @@ static int bcm_sysport_map_queues(struct notifier_block *nb,
 	struct bcm_sysport_priv *priv;
 	struct net_device *slave_dev;
 	unsigned int num_tx_queues;
-	unsigned int q, start, port;
+	unsigned int q, qp, port;
 	struct net_device *dev;
 
 	priv = container_of(nb, struct bcm_sysport_priv, dsa_notifier);
@@ -2363,20 +2363,21 @@ static int bcm_sysport_map_queues(struct notifier_block *nb,
 
 	priv->per_port_num_tx_queues = num_tx_queues;
 
-	start = find_first_zero_bit(&priv->queue_bitmap, dev->num_tx_queues);
-	for (q = 0; q < num_tx_queues; q++) {
-		ring = &priv->tx_rings[q + start];
+	for (q = 0, qp = 0; q < dev->num_tx_queues && qp < num_tx_queues;
+	     q++) {
+		ring = &priv->tx_rings[q];
+
+		if (ring->inspect)
+			continue;
 
 		/* Just remember the mapping actual programming done
 		 * during bcm_sysport_init_tx_ring
 		 */
-		ring->switch_queue = q;
+		ring->switch_queue = qp;
 		ring->switch_port = port;
 		ring->inspect = true;
 		priv->ring_map[q + port * num_tx_queues] = ring;
-
-		/* Set all queues as being used now */
-		set_bit(q + start, &priv->queue_bitmap);
+		qp++;
 	}
 
 	return 0;

drivers/net/ethernet/broadcom/bcmsysport.h

@@ -796,7 +796,6 @@ struct bcm_sysport_priv {
 	/* map information between switch port queues and local queues */
 	struct notifier_block	dsa_notifier;
 	unsigned int		per_port_num_tx_queues;
-	unsigned long		queue_bitmap;
 	struct bcm_sysport_tx_ring *ring_map[DSA_MAX_PORTS * 8];
 
 };