Merge branch 'bpf-hw-offload'

Merge branch 'bpf-hw-offload'

Jakub Kicinski says:

====================
BPF hardware offload (cls_bpf for now)

Rebased and improved.

v7:
 - fix patch 4.
v6 (patch 8 only):
 - explicitly check for registers >= MAX_BPF_REG;
 - fix leaky error path.
v5:
 - fix names of guard defines in bpf_verfier.h.
v4:
 - rename parser -> analyzer;
 - reorganize the analyzer patches a bit;
 - use bitfield.h directly.

--- merge blurb:
In the last year a lot of progress have been made on offloading
simpler TC classifiers.  There is also growing interest in using
BPF for generic high-speed packet processing in the kernel.
It seems beneficial to tie those two trends together and think
about hardware offloads of BPF programs.  This patch set presents
such offload to Netronome smart NICs.  cls_bpf is extended with
hardware offload capabilities and NFP driver gets a JIT translator
which in presence of capable firmware can be used to offload
the BPF program onto the card.

BPF JIT implementation is not 100% complete (e.g. missing instructions)
but it is functional.  Encouragingly it should be possible to
offload most (if not all) advanced BPF features onto the NIC -
including packet modification, maps, tunnel encap/decap etc.

Example of basic tests I used:
  __section_cls_entry
  int cls_entry(struct __sk_buff *skb)
  {
	if (load_byte(skb, 0) != 0x0)
		return 0;

	if (load_byte(skb, 4) != 0x1)
		return 0;

	skb->mark = 0xcafe;

	if (load_byte(skb, 50) != 0xff)
		return 0;

	return ~0U;
  }

Above code can be compiled with Clang and loaded like this:

	ethtool -K p1p1 hw-tc-offload on
	tc qdisc add dev p1p1 ingress
	tc filter add dev p1p1 parent ffff:  bpf obj prog.o action drop

This set implements the basic transparent offload, the skip_{sw,hw}
flags and reporting statistics for cls_bpf.
====================

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