All drivers that use queue management APIs already depend on the netdev
lock. Ultimately, we want to have most of the paths that work with
specific netdev to be rtnl_lock-free (ethtool mostly in particular).
Queue API currently has a much smaller API surface, so start with
rtnl_lock from it:

- add mutex to each dmabuf binding (to replace rtnl_lock)
- move netdev lock management to the callers of netdev_rx_queue_restart
  and drop rtnl_lock

v2:
- drop "net: protect net_devmem_dmabuf_bindings by new
  net_devmem_bindings_mutex" (Jakub)
- add missing mutex_unlock (Jakub)
- undo rtnl_lock removal from netdev_nl_queue_get_doit and
  netdev_nl_queue_get_dumpit, needs more care to grab
  either or but no both rtnl_lock/ops_lock (Jakub)

Cc: Mina Almasry <almasrymina@google.com>

Stanislav Fomichev (3):
  net: create netdev_nl_sock to wrap bindings list
  net: add granular lock for the netdev netlink socket
  net: drop rtnl_lock for queue_mgmt operations

 Documentation/netlink/specs/netdev.yaml   |  4 +--
 drivers/net/ethernet/broadcom/bnxt/bnxt.c |  4 +--
 drivers/net/netdevsim/netdev.c            |  4 +--
 include/net/netdev_netlink.h              | 12 +++++++
 net/core/devmem.c                         |  4 +--
 net/core/netdev-genl-gen.c                |  4 +--
 net/core/netdev-genl-gen.h                |  6 ++--
 net/core/netdev-genl.c                    | 38 +++++++++++++----------
 net/core/netdev_rx_queue.c                | 16 ++++------
 9 files changed, 52 insertions(+), 40 deletions(-)
 create mode 100644 include/net/netdev_netlink.h

-- 
2.48.1