This patch adds support for tc flower hardware offload on the ingress
path. Shared filter blocks are supported by sharing a single ACL table
between multiple ports.

The following flow keys are supported:
 - Ethernet: dst_mac/src_mac
 - IPv4: dst_ip/src_ip/ip_proto/tos
 - VLAN: vlan_id/vlan_prio/vlan_tpid/vlan_dei
 - L4: dst_port/src_port

As per flow actions, the following are supported:
 - drop
 - mirred egress redirect
 - trap
Each ACL entry (filter) can be setup with only one of the listed
actions.

A sorted single linked list is used to keep the ACL entries by their
order of priority. When adding a new filter, this enables us to quickly
ascertain if the new entry has the highest priority of the entire block
or if we should make some space in the ACL table by increasing the
priority of the filters already in the table.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>