[PATCH v2 net-next 2/2] ip6_gre: Make IP6GRE and IP6GRETAP devices always NETIF_F_LLTX

From: Peilin Ye
Date: Fri Apr 29 2022 - 01:26:18 EST


From: Peilin Ye <peilin.ye@xxxxxxxxxxxxx>

Recently we made o_seqno atomic_t. Stop special-casing TUNNEL_SEQ, and
always mark IP6GRE[TAP] devices as NETIF_F_LLTX, since we no longer need
the TX lock (&txq->_xmit_lock).

Signed-off-by: Peilin Ye <peilin.ye@xxxxxxxxxxxxx>
---
(no changes since v1)

net/ipv6/ip6_gre.c | 34 +++++++++++++---------------------
1 file changed, 13 insertions(+), 21 deletions(-)

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 5136959b3dc5..4e37f7c29900 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -382,11 +382,6 @@ static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
goto failed_free;

ip6gre_tnl_link_config(nt, 1);
-
- /* Can use a lockless transmit, unless we generate output sequences */
- if (!(nt->parms.o_flags & TUNNEL_SEQ))
- dev->features |= NETIF_F_LLTX;
-
ip6gre_tunnel_link(ign, nt);
return nt;

@@ -1445,26 +1440,23 @@ static void ip6gre_tunnel_setup(struct net_device *dev)
static void ip6gre_tnl_init_features(struct net_device *dev)
{
struct ip6_tnl *nt = netdev_priv(dev);
+ __be16 flags;

- dev->features |= GRE6_FEATURES;
+ dev->features |= GRE6_FEATURES | NETIF_F_LLTX;
dev->hw_features |= GRE6_FEATURES;

- if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
- /* TCP offload with GRE SEQ is not supported, nor
- * can we support 2 levels of outer headers requiring
- * an update.
- */
- if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
- nt->encap.type == TUNNEL_ENCAP_NONE) {
- dev->features |= NETIF_F_GSO_SOFTWARE;
- dev->hw_features |= NETIF_F_GSO_SOFTWARE;
- }
+ flags = nt->parms.o_flags;

- /* Can use a lockless transmit, unless we generate
- * output sequences
- */
- dev->features |= NETIF_F_LLTX;
- }
+ /* TCP offload with GRE SEQ is not supported, nor can we support 2
+ * levels of outer headers requiring an update.
+ */
+ if (flags & TUNNEL_SEQ)
+ return;
+ if (flags & TUNNEL_CSUM && nt->encap.type != TUNNEL_ENCAP_NONE)
+ return;
+
+ dev->features |= NETIF_F_GSO_SOFTWARE;
+ dev->hw_features |= NETIF_F_GSO_SOFTWARE;
}

static int ip6gre_tunnel_init_common(struct net_device *dev)
--
2.20.1