[PATCH net-next v5 0/3] net: atlantic: Add XDP support

* [PATCH net-next v5 0/3] net: atlantic: Add XDP support
@ 2022-04-17 10:12 Taehee Yoo
  2022-04-17 10:12 ` [PATCH net-next v5 1/3] net: atlantic: Implement xdp control plane Taehee Yoo
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: Taehee Yoo @ 2022-04-17 10:12 UTC (permalink / raw)
  To: davem, kuba, pabeni, netdev, irusskikh, ast, daniel, hawk,
	john.fastabend, andrii, kafai, songliubraving, yhs, kpsingh, bpf
  Cc: ap420073

This patchset is to make atlantic to support multi-buffer XDP.

The first patch implement control plane of xdp.
The aq_xdp(), callback of .xdp_bpf is added.

The second patch implements data plane of xdp.
XDP_TX, XDP_DROP, and XDP_PASS is supported.
__aq_ring_xdp_clean() is added to receive and execute xdp program.
aq_nic_xmit_xdpf() is added to send packet by XDP.

The third patch implements callback of .ndo_xdp_xmit.
aq_xdp_xmit() is added to send redirected packets and it internally
calls aq_nic_xmit_xdpf().

Memory model is MEM_TYPE_PAGE_SHARED.

Order-2 page allocation is used when XDP is enabled.

LRO will be disabled if XDP program doesn't supports multi buffer.

AQC chip supports 32 multi-queues and 8 vectors(irq).
There are two options.
1. under 8 cores and maximum 4 tx queues per core.
2. under 4 cores and maximum 8 tx queues per core.

Like other drivers, these tx queues can be used only for XDP_TX,
XDP_REDIRECT queue. If so, no tx_lock is needed.
But this patchset doesn't use this strategy because getting hardware tx
queue index cost is too high.
So, tx_lock is used in the aq_nic_xmit_xdpf().

single-core, single queue, 80% cpu utilization.

  32.30%  [kernel]                  [k] aq_get_rxpages_xdp
  10.44%  [kernel]                  [k] aq_hw_read_reg <---------- here
   9.86%  bpf_prog_xxx_xdp_prog_tx  [k] bpf_prog_xxx_xdp_prog_tx
   5.51%  [kernel]                  [k] aq_ring_rx_clean

single-core, 8 queues, 100% cpu utilization, half PPS.

  52.03%  [kernel]                  [k] aq_hw_read_reg <---------- here
  18.24%  [kernel]                  [k] aq_get_rxpages_xdp
   4.30%  [kernel]                  [k] hw_atl_b0_hw_ring_rx_receive
   4.24%  bpf_prog_xxx_xdp_prog_tx  [k] bpf_prog_xxx_xdp_prog_tx
   2.79%  [kernel]                  [k] aq_ring_rx_clean

Performance result(64 Byte)
1. XDP_TX
  a. xdp_geieric, single core
    - 2.5Mpps, 100% cpu
  b. xdp_driver, single core
    - 4.5Mpps, 80% cpu
  c. xdp_generic, 8 core(hyper thread)
    - 6.3Mpps, 40% cpu
  d. xdp_driver, 8 core(hyper thread)
    - 6.3Mpps, 30% cpu

2. XDP_REDIRECT
  a. xdp_generic, single core
    - 2.3Mpps
  b. xdp_driver, single core
    - 4.5Mpps

v5:
 - Use MEM_TYPE_PAGE_SHARED instead of MEM_TYPE_PAGE_ORDER0
 - Use 2K frame size instead of 3K
 - Use order-2 page allocation instead of order-0
 - Rename aq_get_rxpage() to aq_alloc_rxpages()
 - Add missing PageFree stats for ethtool
 - Remove aq_unset_rxpage_xdp(), introduced by v2 patch due to
   change of memory model
 - Fix wrong last parameter value of xdp_prepare_buff()
 - Add aq_get_rxpages_xdp() to increase page reference count

v4:
 - Fix compile warning

v3:
 - Change wrong PPS performance result 40% -> 80% in single
   core(Intel i3-12100)
 - Separate aq_nic_map_xdp() from aq_nic_map_skb()
 - Drop multi buffer packets if single buffer XDP is attached
 - Disable LRO when single buffer XDP is attached
 - Use xdp_get_{frame/buff}_len()

v2:
 - Do not use inline in C file

Taehee Yoo (3):
  net: atlantic: Implement xdp control plane
  net: atlantic: Implement xdp data plane
  net: atlantic: Implement .ndo_xdp_xmit handler

 .../net/ethernet/aquantia/atlantic/aq_cfg.h   |   1 +
 .../ethernet/aquantia/atlantic/aq_ethtool.c   |   9 +
 .../net/ethernet/aquantia/atlantic/aq_main.c  |  87 ++++
 .../net/ethernet/aquantia/atlantic/aq_main.h  |   2 +
 .../net/ethernet/aquantia/atlantic/aq_nic.c   | 136 ++++++
 .../net/ethernet/aquantia/atlantic/aq_nic.h   |   5 +
 .../net/ethernet/aquantia/atlantic/aq_ring.c  | 409 ++++++++++++++++--
 .../net/ethernet/aquantia/atlantic/aq_ring.h  |  21 +-
 .../net/ethernet/aquantia/atlantic/aq_vec.c   |  23 +-
 .../net/ethernet/aquantia/atlantic/aq_vec.h   |   6 +
 .../aquantia/atlantic/hw_atl/hw_atl_a0.c      |   6 +-
 .../aquantia/atlantic/hw_atl/hw_atl_b0.c      |  10 +-
 12 files changed, 670 insertions(+), 45 deletions(-)

-- 
2.17.1

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