tun: Implement ethtool's get_channels() callback

Implement the tun .get_channels functionality. This feature is necessary
for some tools, such as libxdp, which need to retrieve the queue count.

Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index e335ece47dec791c8fe82f11845950f3867d1836..b472f2c972d84936d8a53f7784bddec7a1370a0c 100644 (file)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -3643,12 +3643,22 @@ static int tun_set_coalesce(struct net_device *dev,
        return 0;
 }
 
+static void tun_get_channels(struct net_device *dev,
+                            struct ethtool_channels *channels)
+{
+       struct tun_struct *tun = netdev_priv(dev);
+
+       channels->combined_count = tun->numqueues;
+       channels->max_combined = tun->flags & IFF_MULTI_QUEUE ? MAX_TAP_QUEUES : 1;
+}
+
 static const struct ethtool_ops tun_ethtool_ops = {
        .supported_coalesce_params = ETHTOOL_COALESCE_RX_MAX_FRAMES,
        .get_drvinfo    = tun_get_drvinfo,
        .get_msglevel   = tun_get_msglevel,
        .set_msglevel   = tun_set_msglevel,
        .get_link       = ethtool_op_get_link,
+       .get_channels   = tun_get_channels,
        .get_ts_info    = ethtool_op_get_ts_info,
        .get_coalesce   = tun_get_coalesce,
        .set_coalesce   = tun_set_coalesce,