net: systemport: Correclty disambiguate driver instances

While adding the DSA notifier, we will be sending DSA notifications with
info->master that is going to point to a particular net_device instance.

Our logic in bcm_sysport_map_queues() correctly disambiguates net_device
instances that are not covered by our own driver, but it will not make
sure that info->master points to a particular driver instance that we
are interested in. In a system where e.g: two or more SYSTEMPORT
instances are registered, this would lead in programming two or more
times the queue mapping, completely messing with the logic which does
the queue/port allocation and tracking.

Fix this by looking at the notifier_block pointer which is unique per
instance and allows us to go back to our driver private structure, and
in turn to the backing net_device instance.

Fixes: d156576362c0 ("net: systemport: Establish lower/upper queue mapping")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index f9a3c1a..0c2b0fa 100644 (file)
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -2144,14 +2144,21 @@ static const struct net_device_ops bcm_sysport_netdev_ops = {
        .ndo_select_queue       = bcm_sysport_select_queue,
 };
 
-static int bcm_sysport_map_queues(struct net_device *dev,
+static int bcm_sysport_map_queues(struct notifier_block *nb,
                                  struct dsa_notifier_register_info *info)
 {
-       struct bcm_sysport_priv *priv = netdev_priv(dev);
        struct bcm_sysport_tx_ring *ring;
+       struct bcm_sysport_priv *priv;
        struct net_device *slave_dev;
        unsigned int num_tx_queues;
        unsigned int q, start, port;
+       struct net_device *dev;
+
+       priv = container_of(nb, struct bcm_sysport_priv, dsa_notifier);
+       if (priv->netdev != info->master)
+               return 0;
+
+       dev = info->master;
 
        /* We can't be setting up queue inspection for non directly attached
         * switches
@@ -2174,6 +2181,7 @@ static int bcm_sysport_map_queues(struct net_device *dev,
        if (priv->is_lite)
                netif_set_real_num_tx_queues(slave_dev,
                                             slave_dev->num_tx_queues / 2);
+
        num_tx_queues = slave_dev->real_num_tx_queues;
 
        if (priv->per_port_num_tx_queues &&
@@ -2201,7 +2209,7 @@ static int bcm_sysport_map_queues(struct net_device *dev,
        return 0;
 }
 
-static int bcm_sysport_dsa_notifier(struct notifier_block *unused,
+static int bcm_sysport_dsa_notifier(struct notifier_block *nb,
                                    unsigned long event, void *ptr)
 {
        struct dsa_notifier_register_info *info;
@@ -2211,7 +2219,7 @@ static int bcm_sysport_dsa_notifier(struct notifier_block *unused,
 
        info = ptr;
 
-       return notifier_from_errno(bcm_sysport_map_queues(info->master, info));
+       return notifier_from_errno(bcm_sysport_map_queues(nb, info));
 }
 
 #define REV_FMT        "v%2x.%02x"