ieee802154: add wpan_dev_list

This patch adds a wpan_dev_list list into cfg802154_registered_device
struct. Also adding new wpan_dev into this list while
cfg802154_netdev_notifier_call. This behaviour is mostly grab from
wireless core.c implementation and is needed for preparing nl802154
framework.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

2 files changed, 103 insertions, 3 deletions

diff --git a/net/ieee802154/core.c b/net/ieee802154/core.c
index 11a1d2ed5b26..3ee00bf0e514 100644
--- a/net/ieee802154/core.c
+++ b/net/ieee802154/core.c
@@ -102,12 +102,15 @@ wpan_phy_new(const struct cfg802154_ops *ops, size_t priv_size)
 
         mutex_init(&rdev->wpan_phy.pib_lock);
 
+        INIT_LIST_HEAD(&rdev->wpan_dev_list);
         device_initialize(&rdev->wpan_phy.dev);
         dev_set_name(&rdev->wpan_phy.dev, "wpan-phy%d", rdev->wpan_phy_idx);
 
         rdev->wpan_phy.dev.class = &wpan_phy_class;
         rdev->wpan_phy.dev.platform_data = rdev;
 
+        init_waitqueue_head(&rdev->dev_wait);
+
         return &rdev->wpan_phy;
 }
 EXPORT_SYMBOL(wpan_phy_new);
@@ -140,13 +143,18 @@ void wpan_phy_unregister(struct wpan_phy *phy)
 {
         struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
 
-        /* TODO open count */
+        wait_event(rdev->dev_wait, ({
+                int __count;
+                rtnl_lock();
+                __count = rdev->opencount;
+                rtnl_unlock();
+                __count == 0; }));
 
         rtnl_lock();
         /* TODO nl802154 phy notify */
         /* TODO phy registered lock */
 
-        /* TODO WARN_ON wpan_dev_list */
+        WARN_ON(!list_empty(&rdev->wpan_dev_list));
 
         /* First remove the hardware from everywhere, this makes
          * it impossible to find from userspace.
@@ -173,6 +181,79 @@ void cfg802154_dev_free(struct cfg802154_registered_device *rdev)
         kfree(rdev);
 }
 
+static void
+cfg802154_update_iface_num(struct cfg802154_registered_device *rdev,
+                           int iftype, int num)
+{
+        ASSERT_RTNL();
+
+        rdev->num_running_ifaces += num;
+}
+
+static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
+                                          unsigned long state, void *ptr)
+{
+        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+        struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
+        struct cfg802154_registered_device *rdev;
+
+        if (!wpan_dev)
+                return NOTIFY_DONE;
+
+        rdev = wpan_phy_to_rdev(wpan_dev->wpan_phy);
+
+        /* TODO WARN_ON unspec type */
+
+        switch (state) {
+                /* TODO NETDEV_DEVTYPE */
+        case NETDEV_REGISTER:
+                wpan_dev->identifier = ++rdev->wpan_dev_id;
+                list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
+                rdev->devlist_generation++;
+
+                wpan_dev->netdev = dev;
+                break;
+        case NETDEV_DOWN:
+                cfg802154_update_iface_num(rdev, wpan_dev->iftype, -1);
+
+                rdev->opencount--;
+                wake_up(&rdev->dev_wait);
+                break;
+        case NETDEV_UP:
+                cfg802154_update_iface_num(rdev, wpan_dev->iftype, 1);
+
+                rdev->opencount++;
+                break;
+        case NETDEV_UNREGISTER:
+                /* It is possible to get NETDEV_UNREGISTER
+                 * multiple times. To detect that, check
+                 * that the interface is still on the list
+                 * of registered interfaces, and only then
+                 * remove and clean it up.
+                 */
+                if (!list_empty(&wpan_dev->list)) {
+                        list_del_rcu(&wpan_dev->list);
+                        rdev->devlist_generation++;
+                }
+                /* synchronize (so that we won't find this netdev
+                 * from other code any more) and then clear the list
+                 * head so that the above code can safely check for
+                 * !list_empty() to avoid double-cleanup.
+                 */
+                synchronize_rcu();
+                INIT_LIST_HEAD(&wpan_dev->list);
+                break;
+        default:
+                return NOTIFY_DONE;
+        }
+
+        return NOTIFY_OK;
+}
+
+static struct notifier_block cfg802154_netdev_notifier = {
+        .notifier_call = cfg802154_netdev_notifier_call,
+};
+
 static int __init wpan_phy_class_init(void)
 {
         int rc;
@@ -181,11 +262,18 @@ static int __init wpan_phy_class_init(void)
         if (rc)
                 goto err;
 
-        rc = ieee802154_nl_init();
+        rc = register_netdevice_notifier(&cfg802154_netdev_notifier);
         if (rc)
                 goto err_nl;
 
+        rc = ieee802154_nl_init();
+        if (rc)
+                goto err_notifier;
+
         return 0;
+
+err_notifier:
+        unregister_netdevice_notifier(&cfg802154_netdev_notifier);
 err_nl:
         wpan_phy_sysfs_exit();
 err:
@@ -196,6 +284,7 @@ subsys_initcall(wpan_phy_class_init);
 static void __exit wpan_phy_class_exit(void)
 {
         ieee802154_nl_exit();
+        unregister_netdevice_notifier(&cfg802154_netdev_notifier);
         wpan_phy_sysfs_exit();
 }
 module_exit(wpan_phy_class_exit);
diff --git a/net/ieee802154/core.h b/net/ieee802154/core.h
index 38887cb2eaf4..e708d9d5878b 100644
--- a/net/ieee802154/core.h
+++ b/net/ieee802154/core.h
@@ -10,6 +10,17 @@ struct cfg802154_registered_device {
         /* wpan_phy index, internal only */
         int wpan_phy_idx;
 
+        /* also protected by devlist_mtx */
+        int opencount;
+        wait_queue_head_t dev_wait;
+
+        /* protected by RTNL only */
+        int num_running_ifaces;
+
+        /* associated wpan interfaces, protected by rtnl or RCU */
+        struct list_head wpan_dev_list;
+        int devlist_generation, wpan_dev_id;
+
         /* must be last because of the way we do wpan_phy_priv(),
          * and it should at least be aligned to NETDEV_ALIGN
          */