IB/ipoib: Support SendOnlyFullMember MCG for SendOnly join

Check (via an SA query) if the SM supports the new option for SendOnly
multicast joins.
If the SM supports that option it will use the new join state to create
such multicast group.
If SendOnlyFullMember is supported, we wouldn't use faked FullMember state
join for SendOnly MCG, use the correct state if supported.

This check is performed at every invocation of mcast_restart task, to be
sure that the driver stays in sync with the current state of the SM.

Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 25 insertions, 13 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 25889311b1e9..fc3e50e8e391 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -64,6 +64,9 @@ struct ipoib_mcast_iter {
 	unsigned int       send_only;
 };
 
+/* join state that allows creating mcg with sendonly member request */
+#define SENDONLY_FULLMEMBER_JOIN	8
+
 /*
  * This should be called with the priv->lock held
  */
@@ -326,12 +329,23 @@ void ipoib_mcast_carrier_on_task(struct work_struct *work)
 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
 						   carrier_on_task);
 	struct ib_port_attr attr;
+	int ret;
 
 	if (ib_query_port(priv->ca, priv->port, &attr) ||
 	    attr.state != IB_PORT_ACTIVE) {
 		ipoib_dbg(priv, "Keeping carrier off until IB port is active\n");
 		return;
 	}
+	/*
+	 * Check if can send sendonly MCG's with sendonly-fullmember join state.
+	 * It done here after the successfully join to the broadcast group,
+	 * because the broadcast group must always be joined first and is always
+	 * re-joined if the SM changes substantially.
+	 */
+	ret = ipoib_check_sm_sendonly_fullmember_support(priv);
+	if (ret < 0)
+		pr_debug("%s failed query sm support for sendonly-fullmember (ret: %d)\n",
+			 priv->dev->name, ret);
 
 	/*
 	 * Take rtnl_lock to avoid racing with ipoib_stop() and
@@ -515,22 +529,20 @@ static int ipoib_mcast_join(struct net_device *dev, struct ipoib_mcast *mcast)
 		rec.hop_limit	  = priv->broadcast->mcmember.hop_limit;
 
 		/*
-		 * Send-only IB Multicast joins do not work at the core
-		 * IB layer yet, so we can't use them here.  However,
-		 * we are emulating an Ethernet multicast send, which
-		 * does not require a multicast subscription and will
-		 * still send properly.  The most appropriate thing to
+		 * Send-only IB Multicast joins work at the core IB layer but
+		 * require specific SM support.
+		 * We can use such joins here only if the current SM supports that feature.
+		 * However, if not, we emulate an Ethernet multicast send,
+		 * which does not require a multicast subscription and will
+		 * still send properly. The most appropriate thing to
 		 * do is to create the group if it doesn't exist as that
 		 * most closely emulates the behavior, from a user space
-		 * application perspecitive, of Ethernet multicast
-		 * operation.  For now, we do a full join, maybe later
-		 * when the core IB layers support send only joins we
-		 * will use them.
+		 * application perspective, of Ethernet multicast operation.
 		 */
-#if 0
-		if (test_bit(IPOIB_MCAST_FLAG_SENDONLY, &mcast->flags))
-			rec.join_state = 4;
-#endif
+		if (test_bit(IPOIB_MCAST_FLAG_SENDONLY, &mcast->flags) &&
+		    priv->sm_fullmember_sendonly_support)
+			/* SM supports sendonly-fullmember, otherwise fallback to full-member */
+			rec.join_state = SENDONLY_FULLMEMBER_JOIN;
 	}
 	spin_unlock_irq(&priv->lock);