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Diffstat (limited to 'Documentation/networking/netdevices.rst')
| -rw-r--r-- | Documentation/networking/netdevices.rst | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/Documentation/networking/netdevices.rst b/Documentation/networking/netdevices.rst index ebb868f50ac2..eab601ab2db0 100644 --- a/Documentation/networking/netdevices.rst +++ b/Documentation/networking/netdevices.rst @@ -338,10 +338,35 @@ operations directly under the netdev instance lock. Devices drivers are encouraged to rely on the instance lock where possible. For the (mostly software) drivers that need to interact with the core stack, -there are two sets of interfaces: ``dev_xxx`` and ``netif_xxx`` (e.g., -``dev_set_mtu`` and ``netif_set_mtu``). The ``dev_xxx`` functions handle -acquiring the instance lock themselves, while the ``netif_xxx`` functions -assume that the driver has already acquired the instance lock. +there are two sets of interfaces: ``dev_xxx``/``netdev_xxx`` and ``netif_xxx`` +(e.g., ``dev_set_mtu`` and ``netif_set_mtu``). The ``dev_xxx``/``netdev_xxx`` +functions handle acquiring the instance lock themselves, while the +``netif_xxx`` functions assume that the driver has already acquired +the instance lock. + +Notifiers and netdev instance lock +================================== + +For device drivers that implement shaping or queue management APIs, +some of the notifiers (``enum netdev_cmd``) are running under the netdev +instance lock. + +For devices with locked ops, currently only the following notifiers are +running under the lock: +* ``NETDEV_REGISTER`` +* ``NETDEV_UP`` +* ``NETDEV_CHANGE`` + +The following notifiers are running without the lock: +* ``NETDEV_UNREGISTER`` + +There are no clear expectations for the remaining notifiers. Notifiers not on +the list may run with or without the instance lock, potentially even invoking +the same notifier type with and without the lock from different code paths. +The goal is to eventually ensure that all (or most, with a few documented +exceptions) notifiers run under the instance lock. Please extend this +documentation whenever you make explicit assumption about lock being held +from a notifier. NETDEV_INTERNAL symbol namespace ================================ |