IB/mlx5: Support IB device's callback for getting its netdev

For Eth ports only:
Maintain a net device pointer in mlx5_ib_device and update it
upon NETDEV_REGISTER and NETDEV_UNREGISTER events if the
net-device and IB device have the same PCI parent device.
Implement the get_netdev callback to return this net device.

Signed-off-by: Achiad Shochat <achiad@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index a3295bb158912fd8e8548c51a4151c9f8a43d4e1..8c6e144ae75b3337624c2d2ba3e1892785c4d2c8 100644 (file)
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -85,6 +85,41 @@ mlx5_ib_port_link_layer(struct ib_device *device, u8 port_num)
        return mlx5_port_type_cap_to_rdma_ll(port_type_cap);
 }
 
+static int mlx5_netdev_event(struct notifier_block *this,
+                            unsigned long event, void *ptr)
+{
+       struct net_device *ndev = netdev_notifier_info_to_dev(ptr);
+       struct mlx5_ib_dev *ibdev = container_of(this, struct mlx5_ib_dev,
+                                                roce.nb);
+
+       if ((event != NETDEV_UNREGISTER) && (event != NETDEV_REGISTER))
+               return NOTIFY_DONE;
+
+       write_lock(&ibdev->roce.netdev_lock);
+       if (ndev->dev.parent == &ibdev->mdev->pdev->dev)
+               ibdev->roce.netdev = (event == NETDEV_UNREGISTER) ? NULL : ndev;
+       write_unlock(&ibdev->roce.netdev_lock);
+
+       return NOTIFY_DONE;
+}
+
+static struct net_device *mlx5_ib_get_netdev(struct ib_device *device,
+                                            u8 port_num)
+{
+       struct mlx5_ib_dev *ibdev = to_mdev(device);
+       struct net_device *ndev;
+
+       /* Ensure ndev does not disappear before we invoke dev_hold()
+        */
+       read_lock(&ibdev->roce.netdev_lock);
+       ndev = ibdev->roce.netdev;
+       if (ndev)
+               dev_hold(ndev);
+       read_unlock(&ibdev->roce.netdev_lock);
+
+       return ndev;
+}
+
 static int mlx5_use_mad_ifc(struct mlx5_ib_dev *dev)
 {
        return !dev->mdev->issi;
@@ -1329,6 +1364,17 @@ static int mlx5_port_immutable(struct ib_device *ibdev, u8 port_num,
        return 0;
 }
 
+static int mlx5_enable_roce(struct mlx5_ib_dev *dev)
+{
+       dev->roce.nb.notifier_call = mlx5_netdev_event;
+       return register_netdevice_notifier(&dev->roce.nb);
+}
+
+static void mlx5_disable_roce(struct mlx5_ib_dev *dev)
+{
+       unregister_netdevice_notifier(&dev->roce.nb);
+}
+
 static void *mlx5_ib_add(struct mlx5_core_dev *mdev)
 {
        struct mlx5_ib_dev *dev;
@@ -1352,6 +1398,7 @@ static void *mlx5_ib_add(struct mlx5_core_dev *mdev)
 
        dev->mdev = mdev;
 
+       rwlock_init(&dev->roce.netdev_lock);
        err = get_port_caps(dev);
        if (err)
                goto err_dealloc;
@@ -1402,6 +1449,8 @@ static void *mlx5_ib_add(struct mlx5_core_dev *mdev)
        dev->ib_dev.query_device        = mlx5_ib_query_device;
        dev->ib_dev.query_port          = mlx5_ib_query_port;
        dev->ib_dev.get_link_layer      = mlx5_ib_port_link_layer;
+       if (ll == IB_LINK_LAYER_ETHERNET)
+               dev->ib_dev.get_netdev  = mlx5_ib_get_netdev;
        dev->ib_dev.query_gid           = mlx5_ib_query_gid;
        dev->ib_dev.query_pkey          = mlx5_ib_query_pkey;
        dev->ib_dev.modify_device       = mlx5_ib_modify_device;
@@ -1458,9 +1507,15 @@ static void *mlx5_ib_add(struct mlx5_core_dev *mdev)
 
        mutex_init(&dev->cap_mask_mutex);
 
+       if (ll == IB_LINK_LAYER_ETHERNET) {
+               err = mlx5_enable_roce(dev);
+               if (err)
+                       goto err_dealloc;
+       }
+
        err = create_dev_resources(&dev->devr);
        if (err)
-               goto err_dealloc;
+               goto err_disable_roce;
 
        err = mlx5_ib_odp_init_one(dev);
        if (err)
@@ -1497,6 +1552,10 @@ err_odp:
 err_rsrc:
        destroy_dev_resources(&dev->devr);
 
+err_disable_roce:
+       if (ll == IB_LINK_LAYER_ETHERNET)
+               mlx5_disable_roce(dev);
+
 err_dealloc:
        ib_dealloc_device((struct ib_device *)dev);
 
@@ -1506,11 +1565,14 @@ err_dealloc:
 static void mlx5_ib_remove(struct mlx5_core_dev *mdev, void *context)
 {
        struct mlx5_ib_dev *dev = context;
+       enum rdma_link_layer ll = mlx5_ib_port_link_layer(&dev->ib_dev, 1);
 
        ib_unregister_device(&dev->ib_dev);
        destroy_umrc_res(dev);
        mlx5_ib_odp_remove_one(dev);
        destroy_dev_resources(&dev->devr);
+       if (ll == IB_LINK_LAYER_ETHERNET)
+               mlx5_disable_roce(dev);
        ib_dealloc_device(&dev->ib_dev);
 }
 

diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index 633347260b79454ba10da9de498bc9d68d5a6f9f..1eaa6111dce01cc91ce67d2cc75a9ad428126607 100644 (file)
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -407,9 +407,19 @@ struct mlx5_ib_resources {
        struct ib_srq   *s1;
 };
 
+struct mlx5_roce {
+       /* Protect mlx5_ib_get_netdev from invoking dev_hold() with a NULL
+        * netdev pointer
+        */
+       rwlock_t                netdev_lock;
+       struct net_device       *netdev;
+       struct notifier_block   nb;
+};
+
 struct mlx5_ib_dev {
        struct ib_device                ib_dev;
        struct mlx5_core_dev            *mdev;
+       struct mlx5_roce                roce;
        MLX5_DECLARE_DOORBELL_LOCK(uar_lock);
        int                             num_ports;
        /* serialize update of capability mask