netvsc: change max channel calculation

The default number of maximum channels should be limited to the
number of cpus available on the numa node of the primary channel.
This also makes sure maximum channels <= num_online_cpus

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/hyperv/netvsc_drv.c

@@ -1503,8 +1503,7 @@ static int netvsc_probe(struct hv_device *dev,
 	/* Notify the netvsc driver of the new device */
 	memset(&device_info, 0, sizeof(device_info));
 	device_info.ring_size = ring_size;
-	device_info.max_num_vrss_chns = min_t(u32, VRSS_CHANNEL_DEFAULT,
-					      num_online_cpus());
+	device_info.num_chn = VRSS_CHANNEL_DEFAULT;
 	ret = rndis_filter_device_add(dev, &device_info);
 	if (ret != 0) {
 		netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);

drivers/net/hyperv/rndis_filter.c

@@ -1181,33 +1181,28 @@ int rndis_filter_device_add(struct hv_device *dev,
 	if (ret || rsscap.num_recv_que < 2)
 		goto out;
 
-	net_device->max_chn = min_t(u32, VRSS_CHANNEL_MAX, rsscap.num_recv_que);
-
-	num_rss_qs = min(device_info->max_num_vrss_chns, net_device->max_chn);
-
 	/*
 	 * We will limit the VRSS channels to the number CPUs in the NUMA node
 	 * the primary channel is currently bound to.
+	 *
+	 * This also guarantees that num_possible_rss_qs <= num_online_cpus
 	 */
 	node_cpu_mask = cpumask_of_node(cpu_to_node(dev->channel->target_cpu));
-	num_possible_rss_qs = cpumask_weight(node_cpu_mask);
+	num_possible_rss_qs = min_t(u32, cpumask_weight(node_cpu_mask),
+				    rsscap.num_recv_que);
 
-	/* We will use the given number of channels if available. */
-	if (device_info->num_chn && device_info->num_chn < net_device->max_chn)
-		net_device->num_chn = device_info->num_chn;
-	else
-		net_device->num_chn = min(num_possible_rss_qs, num_rss_qs);
+	net_device->max_chn = min_t(u32, VRSS_CHANNEL_MAX, num_possible_rss_qs);
 
-	num_rss_qs = net_device->num_chn - 1;
+	/* We will use the given number of channels if available. */
+	net_device->num_chn = min(net_device->max_chn, device_info->num_chn);
 
 	for (i = 0; i < ITAB_NUM; i++)
 		rndis_device->ind_table[i] = ethtool_rxfh_indir_default(i,
 							net_device->num_chn);
 
-	net_device->num_sc_offered = num_rss_qs;
-
-	if (net_device->num_chn == 1)
-		goto out;
+	num_rss_qs = net_device->num_chn - 1;
+	if (num_rss_qs == 0)
+		return 0;
 
 	vmbus_set_sc_create_callback(dev->channel, netvsc_sc_open);