net: devlink: track netdev with devlink_port assigned

Currently, ethernet drivers are using devlink_port_type_eth_set() and
devlink_port_type_clear() to set devlink port type and link to related
netdev.

Instead of calling them directly, let the driver use
SET_NETDEV_DEVLINK_PORT macro to assign devlink_port pointer and let
devlink to track it. Note the devlink port pointer is static during
the time netdevice is registered.

In devlink code, use per-namespace netdev notifier to track
the netdevices with devlink_port assigned and change the internal
devlink_port type and related type pointer accordingly.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 4b5052d..f048a30 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1999,6 +1999,11 @@ enum netdev_ml_priv_type {
  *                                     registered
  *     @offload_xstats_l3:     L3 HW stats for this netdevice.
  *
+ *     @devlink_port:  Pointer to related devlink port structure.
+ *                     Assigned by a driver before netdev registration using
+ *                     SET_NETDEV_DEVLINK_PORT macro. This pointer is static
+ *                     during the time netdevice is registered.
+ *
  *     FIXME: cleanup struct net_device such that network protocol info
  *     moves out.
  */
@@ -2349,9 +2354,22 @@ struct net_device {
        netdevice_tracker       watchdog_dev_tracker;
        netdevice_tracker       dev_registered_tracker;
        struct rtnl_hw_stats64  *offload_xstats_l3;
+
+       struct devlink_port     *devlink_port;
 };
 #define to_net_dev(d) container_of(d, struct net_device, dev)
 
+/*
+ * Driver should use this to assign devlink port instance to a netdevice
+ * before it registers the netdevice. Therefore devlink_port is static
+ * during the netdev lifetime after it is registered.
+ */
+#define SET_NETDEV_DEVLINK_PORT(dev, port)                     \
+({                                                             \
+       WARN_ON((dev)->reg_state != NETREG_UNINITIALIZED);      \
+       ((dev)->devlink_port = (port));                         \
+})
+
 static inline bool netif_elide_gro(const struct net_device *dev)
 {
        if (!(dev->features & NETIF_F_GRO) || dev->xdp_prog)
@@ -2785,6 +2803,7 @@ enum netdev_cmd {
        NETDEV_PRE_TYPE_CHANGE,
        NETDEV_POST_TYPE_CHANGE,
        NETDEV_POST_INIT,
+       NETDEV_PRE_UNINIT,
        NETDEV_RELEASE,
        NETDEV_NOTIFY_PEERS,
        NETDEV_JOIN,

diff --git a/net/core/dev.c b/net/core/dev.c
index 2e4f1c9..3bacee3 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1621,10 +1621,10 @@ const char *netdev_cmd_to_name(enum netdev_cmd cmd)
        N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
        N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
        N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
-       N(POST_INIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN) N(CHANGEUPPER)
-       N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA) N(BONDING_INFO)
-       N(PRECHANGEUPPER) N(CHANGELOWERSTATE) N(UDP_TUNNEL_PUSH_INFO)
-       N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
+       N(POST_INIT) N(PRE_UNINIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN)
+       N(CHANGEUPPER) N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA)
+       N(BONDING_INFO) N(PRECHANGEUPPER) N(CHANGELOWERSTATE)
+       N(UDP_TUNNEL_PUSH_INFO) N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
        N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
        N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
        N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
@@ -10060,7 +10060,7 @@ int register_netdevice(struct net_device *dev)
        dev->reg_state = ret ? NETREG_UNREGISTERED : NETREG_REGISTERED;
        write_unlock(&dev_base_lock);
        if (ret)
-               goto err_uninit;
+               goto err_uninit_notify;
 
        __netdev_update_features(dev);
 
@@ -10107,6 +10107,8 @@ int register_netdevice(struct net_device *dev)
 out:
        return ret;
 
+err_uninit_notify:
+       call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
 err_uninit:
        if (dev->netdev_ops->ndo_uninit)
                dev->netdev_ops->ndo_uninit(dev);
@@ -10856,6 +10858,8 @@ void unregister_netdevice_many_notify(struct list_head *head,
                netdev_name_node_alt_flush(dev);
                netdev_name_node_free(dev->name_node);
 
+               call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
+
                if (dev->netdev_ops->ndo_uninit)
                        dev->netdev_ops->ndo_uninit(dev);
 

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 3387dfb..6f06c05 100644 (file)
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -71,6 +71,7 @@ struct devlink {
        refcount_t refcount;
        struct completion comp;
        struct rcu_head rcu;
+       struct notifier_block netdevice_nb;
        char priv[] __aligned(NETDEV_ALIGN);
 };
 
@@ -9615,6 +9616,9 @@ void devlink_set_features(struct devlink *devlink, u64 features)
 }
 EXPORT_SYMBOL_GPL(devlink_set_features);
 
+static int devlink_netdevice_event(struct notifier_block *nb,
+                                  unsigned long event, void *ptr);
+
 /**
  *     devlink_alloc_ns - Allocate new devlink instance resources
  *     in specific namespace
@@ -9645,10 +9649,13 @@ struct devlink *devlink_alloc_ns(const struct devlink_ops *ops,
 
        ret = xa_alloc_cyclic(&devlinks, &devlink->index, devlink, xa_limit_31b,
                              &last_id, GFP_KERNEL);
-       if (ret < 0) {
-               kfree(devlink);
-               return NULL;
-       }
+       if (ret < 0)
+               goto err_xa_alloc;
+
+       devlink->netdevice_nb.notifier_call = devlink_netdevice_event;
+       ret = register_netdevice_notifier_net(net, &devlink->netdevice_nb);
+       if (ret)
+               goto err_register_netdevice_notifier;
 
        devlink->dev = dev;
        devlink->ops = ops;
@@ -9675,6 +9682,12 @@ struct devlink *devlink_alloc_ns(const struct devlink_ops *ops,
        init_completion(&devlink->comp);
 
        return devlink;
+
+err_register_netdevice_notifier:
+       xa_erase(&devlinks, devlink->index);
+err_xa_alloc:
+       kfree(devlink);
+       return NULL;
 }
 EXPORT_SYMBOL_GPL(devlink_alloc_ns);
 
@@ -9828,6 +9841,10 @@ void devlink_free(struct devlink *devlink)
        WARN_ON(!list_empty(&devlink->port_list));
 
        xa_destroy(&devlink->snapshot_ids);
+
+       unregister_netdevice_notifier_net(devlink_net(devlink),
+                                         &devlink->netdevice_nb);
+
        xa_erase(&devlinks, devlink->index);
 
        kfree(devlink);
@@ -10121,6 +10138,56 @@ void devlink_port_type_clear(struct devlink_port *devlink_port)
 }
 EXPORT_SYMBOL_GPL(devlink_port_type_clear);
 
+static int devlink_netdevice_event(struct notifier_block *nb,
+                                  unsigned long event, void *ptr)
+{
+       struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
+       struct devlink_port *devlink_port = netdev->devlink_port;
+       struct devlink *devlink;
+
+       devlink = container_of(nb, struct devlink, netdevice_nb);
+
+       if (!devlink_port || devlink_port->devlink != devlink)
+               return NOTIFY_OK;
+
+       switch (event) {
+       case NETDEV_POST_INIT:
+               /* Set the type but not netdev pointer. It is going to be set
+                * later on by NETDEV_REGISTER event. Happens once during
+                * netdevice register
+                */
+               __devlink_port_type_set(devlink_port, DEVLINK_PORT_TYPE_ETH,
+                                       NULL, true);
+               break;
+       case NETDEV_REGISTER:
+               /* Set the netdev on top of previously set type. Note this
+                * event happens also during net namespace change so here
+                * we take into account netdev pointer appearing in this
+                * namespace.
+                */
+               __devlink_port_type_set(devlink_port, DEVLINK_PORT_TYPE_ETH,
+                                       netdev, true);
+               break;
+       case NETDEV_UNREGISTER:
+               /* Clear netdev pointer, but not the type. This event happens
+                * also during net namespace change so we need to clear
+                * pointer to netdev that is going to another net namespace.
+                */
+               __devlink_port_type_set(devlink_port, DEVLINK_PORT_TYPE_ETH,
+                                       NULL, true);
+               break;
+       case NETDEV_PRE_UNINIT:
+               /* Clear the type and the netdev pointer. Happens one during
+                * netdevice unregister.
+                */
+               __devlink_port_type_set(devlink_port, DEVLINK_PORT_TYPE_NOTSET,
+                                       NULL, true);
+               break;
+       }
+
+       return NOTIFY_OK;
+}
+
 static int __devlink_port_attrs_set(struct devlink_port *devlink_port,
                                    enum devlink_port_flavour flavour)
 {