bql: Byte queue limits

Networking stack support for byte queue limits, uses dynamic queue
limits library.  Byte queue limits are maintained per transmit queue,
and a dql structure has been added to netdev_queue structure for this
purpose.

Configuration of bql is in the tx-<n> sysfs directory for the queue
under the byte_queue_limits directory.  Configuration includes:
limit_min, bql minimum limit
limit_max, bql maximum limit
hold_time, bql slack hold time

Also under the directory are:
limit, current byte limit
inflight, current number of bytes on the queue

Signed-off-by: Tom Herbert <[email protected]>
Acked-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
4 files changed