Re: [PATCH net-next RFC 00/13] Add devlink reload level option

[Vasundhara Volam <vasundhara-v.volam@broadcom.com>]

On Mon, Jul 27, 2020 at 4:36 PM Moshe Shemesh <moshe@mellanox.com> wrote:
>
> Introduce new option on devlink reload API to enable the user to select the
> reload level required. Complete support for all levels in mlx5.
> The following reload levels are supported:
>   driver: Driver entities re-instantiation only.
>   fw_reset: Firmware reset and driver entities re-instantiation.
The Name is a little confusing. I think it should be renamed to
fw_live_reset (in which both firmware and driver entities are
re-instantiated).  For only fw_reset, the driver should not undergo
reset (it requires a driver reload for firmware to undergo reset).

>   fw_live_patch: Firmware live patching only.
This level is not clear. Is this similar to flashing??

Also I have a basic query. The reload command is split into
reload_up/reload_down handlers (Please correct me if this behaviour is
changed with this patchset). What if the vendor specific driver does
not support up/down and needs only a single handler to fire a firmware
reset or firmware live reset command?
>
> Each driver which support this command should expose the reload levels
> supported and the driver's default reload level.
> The uAPI is backward compatible, if the reload level option is omitted
> from the reload command, the driver's default reload level will be used.
>
> Patch 1 adds the new API reload level option to devlink.
> Patch 2 exposes the supported reload levels and default level on devlink
>         dev get.
> Patches 3-8 add support on mlx5 for devlink reload level fw-reset and
>             handle the firmware reset events.
> Patches 9-10 add devlink enable remote dev reset parameter and use it
>              in mlx5.
> Patches 11-12 mlx5 add devlink reload live patch support and event
>               handling.
> Patch 13 adds documentation file devlink-reload.rst
>
> Command examples:
>
> # Run reload command with fw-reset reload level:
> $ devlink dev reload pci/0000:82:00.0 level fw-reset
>
> # Run reload command with driver reload level:
> $ devlink dev reload pci/0000:82:00.0 level driver
>
> # Run reload command with driver's default level (backward compatible):
> $ devlink dev reload pci/0000:82:00.0
>
>
> Moshe Shemesh (13):
>   devlink: Add reload level option to devlink reload command
>   devlink: Add reload levels data to dev get
>   net/mlx5: Add functions to set/query MFRL register
>   net/mlx5: Set cap for pci sync for fw update event
>   net/mlx5: Handle sync reset request event
>   net/mlx5: Handle sync reset now event
>   net/mlx5: Handle sync reset abort event
>   net/mlx5: Add support for devlink reload level fw reset
>   devlink: Add enable_remote_dev_reset generic parameter
>   net/mlx5: Add devlink param enable_remote_dev_reset support
>   net/mlx5: Add support for fw live patch event
>   net/mlx5: Add support for devlink reload level live patch
>   devlink: Add Documentation/networking/devlink/devlink-reload.rst
>
>  .../networking/devlink/devlink-params.rst     |   6 +
>  .../networking/devlink/devlink-reload.rst     |  56 +++
>  Documentation/networking/devlink/index.rst    |   1 +
>  drivers/net/ethernet/mellanox/mlx4/main.c     |   6 +-
>  .../net/ethernet/mellanox/mlx5/core/Makefile  |   2 +-
>  .../net/ethernet/mellanox/mlx5/core/devlink.c | 114 +++++-
>  .../mellanox/mlx5/core/diag/fw_tracer.c       |  31 ++
>  .../mellanox/mlx5/core/diag/fw_tracer.h       |   1 +
>  .../ethernet/mellanox/mlx5/core/fw_reset.c    | 328 ++++++++++++++++++
>  .../ethernet/mellanox/mlx5/core/fw_reset.h    |  17 +
>  .../net/ethernet/mellanox/mlx5/core/health.c  |  74 +++-
>  .../net/ethernet/mellanox/mlx5/core/main.c    |  13 +
>  drivers/net/ethernet/mellanox/mlxsw/core.c    |   6 +-
>  drivers/net/netdevsim/dev.c                   |   6 +-
>  include/linux/mlx5/device.h                   |   1 +
>  include/linux/mlx5/driver.h                   |  12 +
>  include/net/devlink.h                         |  10 +-
>  include/uapi/linux/devlink.h                  |  22 ++
>  net/core/devlink.c                            |  95 ++++-
>  19 files changed, 764 insertions(+), 37 deletions(-)
>  create mode 100644 Documentation/networking/devlink/devlink-reload.rst
>  create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c
>  create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/fw_reset.h
>
> --
> 2.17.1
>