Merge branch 'netdev_features-start-cleaning-netdev_features_t-up'

Alexander Lobakin says:

====================
netdev_features: start cleaning netdev_features_t up

NETDEV_FEATURE_COUNT is currently 64, which means we can't add any new
features as netdev_features_t is u64.
As per several discussions, instead of converting netdev_features_t to
a bitmap, which would mean A LOT of changes, we can try cleaning up
netdev feature bits.
There's a bunch of bits which don't really mean features, rather device
attributes/properties that can't be changed via Ethtool in any of the
drivers. Such attributes can be moved to netdev private flags without
losing any functionality.

Start converting some read-only netdev features to private flags from
the ones that are most obvious, like lockless Tx, inability to change
network namespace etc. I was able to reduce NETDEV_FEATURE_COUNT from
64 to 60, which mean 4 free slots for new features. There are obviously
more read-only features to convert, such as highDMA, "challenged VLAN",
HSR (4 bits) - this will be done in subsequent series.

Please note that currently netdev features are not uAPI/ABI by any means.
Ethtool passes their names and bits to the userspace separately and there
are no hardcoded names/bits in the userspace, so that new Ethtool could
work on older kernels and vice versa.
This, however, isn't true for Ethtools < 3.4. I haven't changed the bit
positions of the already existing features and instead replaced the freed
bits with stubs. But it's anyway theoretically possible that Ethtools
older than 2011 will break. I hope no currently supported distros supply
such an ancient version.
Shell scripts also most likely won't break since the removed bits were
always read-only, meaning nobody would try touching them from a script.
====================

Link: https://patch.msgid.link/20240829123340.789395-1-aleksander.lobakin@intel.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

4 files changed, 9 insertions, 8 deletions

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 3942bd2ade78..235808cfec70 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -1471,7 +1471,7 @@ static void ip6gre_tnl_init_features(struct net_device *dev)
 {
 	struct ip6_tnl *nt = netdev_priv(dev);
 
-	dev->features		|= GRE6_FEATURES | NETIF_F_LLTX;
+	dev->features		|= GRE6_FEATURES;
 	dev->hw_features	|= GRE6_FEATURES;
 
 	/* TCP offload with GRE SEQ is not supported, nor can we support 2
@@ -1485,6 +1485,8 @@ static void ip6gre_tnl_init_features(struct net_device *dev)
 
 	dev->features |= NETIF_F_GSO_SOFTWARE;
 	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+
+	dev->lltx = true;
 }
 
 static int ip6gre_tunnel_init_common(struct net_device *dev)
@@ -1619,8 +1621,7 @@ static int __net_init ip6gre_init_net(struct net *net)
 	/* FB netdevice is special: we have one, and only one per netns.
 	 * Allowing to move it to another netns is clearly unsafe.
 	 */
-	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
-
+	ign->fb_tunnel_dev->netns_local = true;
 
 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 87dfb565a9f8..ec51ab5063e8 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1849,7 +1849,7 @@ static void ip6_tnl_dev_setup(struct net_device *dev)
 	dev->type = ARPHRD_TUNNEL6;
 	dev->flags |= IFF_NOARP;
 	dev->addr_len = sizeof(struct in6_addr);
-	dev->features |= NETIF_F_LLTX;
+	dev->lltx = true;
 	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
 	netif_keep_dst(dev);
 
@@ -2258,7 +2258,7 @@ static int __net_init ip6_tnl_init_net(struct net *net)
 	/* FB netdevice is special: we have one, and only one per netns.
 	 * Allowing to move it to another netns is clearly unsafe.
 	 */
-	ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
+	ip6n->fb_tnl_dev->netns_local = true;
 
 	err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
 	if (err < 0)
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index e3ee93c562c3..2ce4ae0d8dc3 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -640,7 +640,7 @@ static void reg_vif_setup(struct net_device *dev)
 	dev->flags		= IFF_NOARP;
 	dev->netdev_ops		= &reg_vif_netdev_ops;
 	dev->needs_free_netdev	= true;
-	dev->features		|= NETIF_F_NETNS_LOCAL;
+	dev->netns_local	= true;
 }
 
 static struct net_device *ip6mr_reg_vif(struct net *net, struct mr_table *mrt)
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 3b2eed7fc765..16b90a24c9ba 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -1436,7 +1436,7 @@ static void ipip6_tunnel_setup(struct net_device *dev)
 	dev->flags		= IFF_NOARP;
 	netif_keep_dst(dev);
 	dev->addr_len		= 4;
-	dev->features		|= NETIF_F_LLTX;
+	dev->lltx		= true;
 	dev->features		|= SIT_FEATURES;
 	dev->hw_features	|= SIT_FEATURES;
 	dev->pcpu_stat_type	= NETDEV_PCPU_STAT_TSTATS;
@@ -1856,7 +1856,7 @@ static int __net_init sit_init_net(struct net *net)
 	/* FB netdevice is special: we have one, and only one per netns.
 	 * Allowing to move it to another netns is clearly unsafe.
 	 */
-	sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
+	sitn->fb_tunnel_dev->netns_local = true;
 
 	err = register_netdev(sitn->fb_tunnel_dev);
 	if (err)