From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit c146f9bc195a9dc3ad7fd000a14540e7c9df952d ]
DSA needs to simulate master tracking events when a binding is first with a DSA master established and torn down, in order to give drivers the simplifying guarantee that ->master_state_change calls are made only when the master's readiness state to pass traffic changes. master_state_change() provide a operational bool that DSA driver can use to understand if DSA master is operational or not. To avoid races, we need to block the reception of NETDEV_UP/NETDEV_CHANGE/NETDEV_GOING_DOWN events in the netdev notifier chain while we are changing the master's dev->dsa_ptr (this changes what netdev_uses_dsa(dev) reports).
The dsa_master_setup() and dsa_master_teardown() functions optionally require the rtnl_mutex to be held, if the tagger needs the master to be promiscuous, these functions call dev_set_promiscuity(). Move the rtnl_lock() from that function and make it top-level.
Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Reviewed-by: Florian Fainelli f.fainelli@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/dsa/dsa2.c | 8 ++++++++ net/dsa/master.c | 4 ++-- 2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c index e9911b18bdbfa..db9cdfb190fc0 100644 --- a/net/dsa/dsa2.c +++ b/net/dsa/dsa2.c @@ -1011,6 +1011,8 @@ static int dsa_tree_setup_master(struct dsa_switch_tree *dst) struct dsa_port *dp; int err;
+ rtnl_lock(); + list_for_each_entry(dp, &dst->ports, list) { if (dsa_port_is_cpu(dp)) { err = dsa_master_setup(dp->master, dp); @@ -1019,6 +1021,8 @@ static int dsa_tree_setup_master(struct dsa_switch_tree *dst) } }
+ rtnl_unlock(); + return 0; }
@@ -1026,9 +1030,13 @@ static void dsa_tree_teardown_master(struct dsa_switch_tree *dst) { struct dsa_port *dp;
+ rtnl_lock(); + list_for_each_entry(dp, &dst->ports, list) if (dsa_port_is_cpu(dp)) dsa_master_teardown(dp->master); + + rtnl_unlock(); }
static int dsa_tree_setup_lags(struct dsa_switch_tree *dst) diff --git a/net/dsa/master.c b/net/dsa/master.c index e8e19857621bd..16b7dfd22bf5d 100644 --- a/net/dsa/master.c +++ b/net/dsa/master.c @@ -267,9 +267,9 @@ static void dsa_master_set_promiscuity(struct net_device *dev, int inc) if (!ops->promisc_on_master) return;
- rtnl_lock(); + ASSERT_RTNL(); + dev_set_promiscuity(dev, inc); - rtnl_unlock(); }
static ssize_t tagging_show(struct device *d, struct device_attribute *attr,