eea: Add basic driver framework for Alibaba Elastic Ethernet Adaptor

Add a driver framework for EEA that will be available in the future.

This driver is currently quite minimal, implementing only fundamental
core functionalities. Key features include: I/O queue management via
adminq, basic PCI-layer operations, and essential RX/TX data
communication capabilities. It also supports the creation,
initialization, and management of network devices (netdev). Furthermore,
the ring structures for both I/O queues and adminq have been abstracted
into a simple, unified, and reusable library implementation,
facilitating future extension and maintenance.

v21:
    Fix two issues from the previous version:
    1, a DMA unmap operation was missing.
    2, RCU APIs were not used in eea_stats. Although the standard practice when
        using RCU would require adding the __rcu annotation to both the rx and
        tx fields, in many cases these fields are read without needing RCU
        protection.  Therefore, I do not want to add the __rcu annotation.
        Instead, I use a spin lock to protect modifications to rx and tx.

v20:
    Fix the partially initialized structure passed to db. @Jakub
    http://lore.kernel.org/all/20260113172353.2ae6ef81@kernel...

v19:
    fix the comments from @Simon Horman

v18:
    v17 with [PATCH] prefix.

v17:
    1. In `eea_adminq_dev_status`, uniformly use `enet->cfg.rx_ring_num`.
    2. Add a `struct eea_net_cfg *cfg` parameter to `eea_free_rx` and
        `eea_free_tx`. When called in the normal path, pass `enet->cfg` as
        the argument; when called during initialization, pass the temporary
        `cfg` instead.
    3. Move the `.ndo_get_stats64` callback into `eea_net.c`.
    4. In the `.ndo_get_stats64` callback, add a comment explaining how the TX
        and RX statistics are protected by RCU.

       /* This function is protected by RCU. Here uses enet->tx and enet->rx
        * to check whether the TX and RX structures are safe to access. In
        * eea_free_rxtx_q_mem, before freeing the TX and RX resources, enet->rx
        * and enet->tx are set to NULL, and synchronize_net is called.
        */


v16:
    1. follow the advices from @ALOK TIWARI
       http://lore.kernel.org/all/5ff95a71-69e5-4cb6-9b2a-5224c9...

v15:
    1. remove 'default m' from eea kconfig
    2. free the resources when open failed.

v14:
    1. some tiny fixes

v13:
    1. fix some tiny fixes @Simon

v12:
    I encountered some issues with sending the v11 patches, as they were quite
    messy. Therefore, I'm resending them as v12.

v11:
    1. remove auto clean __free(kfree)
    2. some tiny fixes

v10:
    1. name the jump labels after the target @Jakub
    2. rm __GFP_ZERO from dma_alloc_coherent @Jakub
v9:
    1. some fixes for ethtool from http://lore.kernel.org/all/20251027183754.52fe2a2c@kernel...

v8: 1. rename eea_net_tmp to eea_net_init_ctx
    2. rm code that allocs memory to destroy queues
    3. some other minor changes

v7: 1. remove the irrelative code from ethtool commit
    2. build every commits with W12

v6: Split the big one commit to five commits
v5: Thanks for the comments from Kalesh Anakkur Purayil, ALOK TIWARI
v4: Thanks for the comments from Troy Mitchell, Przemek Kitszel, Andrew Lunn, Kalesh Anakkur Purayil
v3: Thanks for the comments from Paolo Abenchi
v2: Thanks for the comments from Simon Horman and Andrew Lunn
v1: Thanks for the comments from Simon Horman and Andrew Lunn
















Xuan Zhuo (6):
  eea: introduce PCI framework
  eea: introduce ring and descriptor structures
  eea: probe the netdevice and create adminq
  eea: create/destroy rx,tx queues for netdevice open and stop
  eea: introduce ethtool support
  eea: introduce callback for ndo_get_stats64

 MAINTAINERS                                   |   8 +
 drivers/net/ethernet/Kconfig                  |   1 +
 drivers/net/ethernet/Makefile                 |   1 +
 drivers/net/ethernet/alibaba/Kconfig          |  28 +
 drivers/net/ethernet/alibaba/Makefile         |   5 +
 drivers/net/ethernet/alibaba/eea/Makefile     |   9 +
 drivers/net/ethernet/alibaba/eea/eea_adminq.c | 421 ++++++++++
 drivers/net/ethernet/alibaba/eea/eea_adminq.h |  70 ++
 drivers/net/ethernet/alibaba/eea/eea_desc.h   | 156 ++++
 .../net/ethernet/alibaba/eea/eea_ethtool.c    | 236 ++++++
 .../net/ethernet/alibaba/eea/eea_ethtool.h    |  49 ++
 drivers/net/ethernet/alibaba/eea/eea_net.c    | 644 ++++++++++++++
 drivers/net/ethernet/alibaba/eea/eea_net.h    | 201 +++++
 drivers/net/ethernet/alibaba/eea/eea_pci.c    | 587 +++++++++++++
 drivers/net/ethernet/alibaba/eea/eea_pci.h    |  67 ++
 drivers/net/ethernet/alibaba/eea/eea_ring.c   | 266 ++++++
 drivers/net/ethernet/alibaba/eea/eea_ring.h   |  91 ++
 drivers/net/ethernet/alibaba/eea/eea_rx.c     | 789 ++++++++++++++++++
 drivers/net/ethernet/alibaba/eea/eea_tx.c     | 404 +++++++++
 19 files changed, 4033 insertions(+)
 create mode 100644 drivers/net/ethernet/alibaba/Kconfig
 create mode 100644 drivers/net/ethernet/alibaba/Makefile
 create mode 100644 drivers/net/ethernet/alibaba/eea/Makefile
 create mode 100644 drivers/net/ethernet/alibaba/eea/eea_adminq.c
 create mode 100644 drivers/net/ethernet/alibaba/eea/eea_adminq.h
 create mode 100644 drivers/net/ethernet/alibaba/eea/eea_desc.h
 create mode 100644 drivers/net/ethernet/alibaba/eea/eea_ethtool.c
 create mode 100644 drivers/net/ethernet/alibaba/eea/eea_ethtool.h
 create mode 100644 drivers/net/ethernet/alibaba/eea/eea_net.c
 create mode 100644 drivers/net/ethernet/alibaba/eea/eea_net.h
 create mode 100644 drivers/net/ethernet/alibaba/eea/eea_pci.c
 create mode 100644 drivers/net/ethernet/alibaba/eea/eea_pci.h
 create mode 100644 drivers/net/ethernet/alibaba/eea/eea_ring.c
 create mode 100644 drivers/net/ethernet/alibaba/eea/eea_ring.h
 create mode 100644 drivers/net/ethernet/alibaba/eea/eea_rx.c
 create mode 100644 drivers/net/ethernet/alibaba/eea/eea_tx.c

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2.32.0.3.g01195cf9f