[PATCH v11 0/4] net/zxdh: optimize Rx/Tx path performance

v11:
  - Restructure queue types for cache locality and dead-code removal (patch 2/4),
    optimize the packed-ring Rx path with a single-segment fast path,
    MTU/scatter refactor, and xstats cleanup (patch 3/4), and rework the
    packed-ring Tx flush with per-descriptor mbuf free, walk budget, and
    masked prefetch index (patch 4/4).

v10:
  - Based on the issues raised in the AI review, Patch 2/4 Patch 3/4 Patch 4/4 have been modified.

v9:
  - Remove add simple Tx xmit functions (zxdh_xmit_pkts_simple) in the last patch.

v8:
  - Add checked the size of ZXDH_DL_NET_HDR_SIZE and RTE_PKTMBUF_HEADROOM in
    zxdh_xmit_pkts_simple() before submitting. Add static_assert to reject builds with insufficient
    default headroom at compile time.

v7:
  - Add a new xmit prepare func for xmit_pkts_simple, which will checked the size of
    ZXDH_DL_NET_HDR_SIZE and RTE_PKTMBUF_HEADROOM.

v6:
  - Remove unnecessary error checking code in submit_to_backend_simple() and
    pkt_padding(). Since as the max dl_net_hdr_len is always less than
    RTE_PKTMBUF_HEADROOM, rte_pktmbuf_prepend() cannot fail in the
    simple path (single-segment mbufs).
v5:
  - Reorganize patch series, placing interrupt fix as the first patch
    and fix condition check to properly enable interrupts.
  - Fix zxdh_recv_single_pkts() not compacting rcv_pkts[] on failure,
    which could cause use-after-free and mbuf leak.
  - Fix tx_bunch() and tx1() missing store barrier before setting AVAIL flag,
    preventing data race on weakly-ordered architectures.
  - Fix submit_to_backend_simple() writing descriptors for packets that
    failed pkt_padding(), causing mbuf leak.
v4:
  - fix some AI review issues.
  - fix queue enable intr bug.
v3:
  - remove unnecessary NULL check in zxdh_init_queue.
  - Split Ring: Bit[31] is unused and reserved, zxdh_queue_notify(): removing the
    zxdh_pci_with_feature(hw, ZXDH_F_RING_PACKED) check;
  - remove unnecessary double-free in in zxdh_recv_single_pkts();
  - used rte_pktmbuf_mtod();
  - remove rxq_get_vq(q) macro, use q->vq and apply it consistently;
  - Refactoring scatter and mtu check logic in zxdh_dev_mtu_set();
  - set txdp->id = avail_idx + i in tx_bunch/tx1.
  - add comment documenting zxdh_xmit_enqueue_append() now sets dxp->cookie = NULL for
    the head slot and stores cookies per descriptor via dep[idx].cookie.
  - add one-line comment noting tx_bunch() is the simple path handles single-segment.
  - remove unnecessary Extra initialization and the uint32_t cast.
v2:
  - zxdh_rxtx.c, pkt_padding(): modifyed the return value of pkt_padding();
  - zxdh_rxtx.c, zxdh_recv_single_pkts(): modifyed When zxdh_init_mbuf() fails
    the loop does "continue" and free mbufs;
  - zxdh_rxtx.c, refill_desc_unwrap(): Add rte_io_wmb() before writing flags
    in the refill_que_descs();
  - zxdh_queue.h, zxdh_queue_enable_intr(): Remove unnecessary function of zxdh_queue_enable_intr;
  - zxdh_ethdev.c, zxdh_init_queue(): changed the hdr_mz NULL check logic;
  - zxdh_rxtx.c, zxdh_xmit_pkts_simple()、zxdh_recv_single_pkts(): add stats.bytes count;
  - zxdh_rxtx.c, zxdh_init_mbuf():remove  rte_pktmbuf_dump(stdout, rxm, 40);
  - zxdh_ethdev.c, zxdh_dev_free_mbufs(): using rte_pktmbuf_free() to free mbufs;
  - Splitting into separate patches, structure reorganization and sw_ring removal、
    RX recv optimize、Tx xmit optimize、Tx;
v1:
  This patch optimizes the ZXDH PMD's receive and transmit path for better
  performance through several improvements:
- Add simple TX/RX burst functions (zxdh_xmit_pkts_simple and
  zxdh_recv_single_pkts) for single-segment packet scenarios.
- Remove RX software ring (sw_ring) to reduce memory allocation and
  copy.
- Optimize descriptor management with prefetching and simplified
  cleanup.
- Reorganize structure fields for better cache locality.

  These changes reduce CPU cycles and memory bandwidth consumption,
  resulting in improved packet processing throughput.

Junlong Wang (4):
  net/zxdh: fix queue enable intr issues
  net/zxdh: optimize queue structure to improve performance
  net/zxdh: optimize Rx recv pkts performance
  net/zxdh: optimize Tx xmit pkts performance

 doc/guides/rel_notes/release_26_11.rst |  10 +
 drivers/net/zxdh/zxdh_ethdev.c         |  85 ++++---
 drivers/net/zxdh/zxdh_ethdev_ops.c     |  22 +-
 drivers/net/zxdh/zxdh_ethdev_ops.h     |   7 +
 drivers/net/zxdh/zxdh_pci.c            |  21 --
 drivers/net/zxdh/zxdh_pci.h            |   1 -
 drivers/net/zxdh/zxdh_queue.c          |  11 +-
 drivers/net/zxdh/zxdh_queue.h          | 134 ++++------
 drivers/net/zxdh/zxdh_rxtx.c           | 323 +++++++++++++++----------
 drivers/net/zxdh/zxdh_rxtx.h           |  15 +-
 10 files changed, 327 insertions(+), 302 deletions(-)

-- 
2.27.0