Merge branch 'flower-offload'

Amir Vadai says:

====================
cls_flower hardware offload support

Please see changes from V2 at the bottom.

This patchset introduces cls_flower hardware offload support over ConnectX-4
driver, more hardware vendors are welcome to use it too.

This patchset is based on John's infrastructure for tc offloading [2] to add
hardware offload support to the flower filter. It also extends the support to
an additional tc action - skbedit mark operation.
NIC driver that was used is ConnectX-4. Feature is off by default and could be
turned on using ethtool.

Some commands to use this code:

export TC=../iproute2/tc/tc
export ETH=ens9

ethtool  -K ens9 hw-tc-offload on

$TC qdisc add dev $ETH ingress

$TC filter add dev $ETH protocol ip prio 20 parent ffff: \
	flower ip_proto 1 \
	dst_mac 7c:fe:90:69:81:62 \
	src_mac 7c:fe:90:69:81:56 \
	dst_ip 11.11.11.11 \
	src_ip 11.11.11.12 \
	indev $ETH \
	action drop

$TC filter add dev $ETH protocol ip prio 30 parent ffff: \
	flower ip_proto 6 \
	indev $ETH \
	action skbedit mark 0x1234

$TC filter add dev $ETH protocol ip prio 10 parent ffff: \
	handle 0x1234 fw action pass

The code was tested and applied on top of commit 3ebeac1 ("Merge branch
'cxgb4-next'")

Changes from V2:
- patch 1/10 ("net/flower: Introduce hardware offload support")
  - Remove unused variable [Dave]
  - Don't fail command when HW can't offload filter [John]
- patch 3/10 ("net/sched: Macro instead of CONFIG_NET_CLS_ACT ifdef")
  - Mention in changelog that struct tc_action is now exposed out of the ifdef.
- patch 4/10 ("net/act_skbedit: Utility functions for mark action")
  - Document clearly that is_tcf_skbedit_mark() is returning true if and only
    if the only action is mark [Dave]
- patch 8/10 ("net/mlx5e: Introduce tc offload support")
  - make mlx5e_tc_add_flow() static

Changes from V1:
- patch 3/10 ("net/sched: Macro instead of CONFIG_NET_CLS_ACT ifdef")
  - fixed return value of tc_no_actions

Changes from V0:
- Use tc_no_actions and tc_for_each_action instead of ifdef CONFIG_NET_CLS_ACT
- Replace ENOTSUPP (and some EINVAL) with EOPNOTSUPP
- Name the flower command enum
- fl_hw_destroy_filter() to return void - nobody uses the return value
- mlx5e_tc_init() and mlx5e_tc_cleanup() to be called from the right places.
- When adding HW rule fails - fail the command
- Rules are added to be processed both by HW and SW unless SKIP_HW is given
- Adding patch 6/10 ("net/mlx5e: Relax ndo_setup_tc handle restriction")

Main changes from the RFC [1]:
- API
  - Using ndo_setup_tc() instead of switchdev
- act_skbedit, act_gact
  - Actions are not serialized to NIC driver, instead using access functions.
- cls_flower
  - prevent double classification by software by not adding
    successfuly offloaded filters to the hashtable
  - Fixed some bugs in original RFC with rule delete
- mlx5
  - Adding flow table to kernel namespace instead of a new namespace
  - s/offload/tc/ in many places
  - no need for a special kconfig since switchdev is not used
====================

Signed-off-by: David S. Miller <davem@davemloft.net>