[PATCH v2] ethdev: fast path async flow API

[Ori Kam]

Hi Draiusz,

> -----Original Message-----
> From: Dariusz Sosnowski <dsosnowski at nvidia.com>
> Sent: Wednesday, January 31, 2024 11:35 AM
> 
> This patch reworks the async flow API functions called in data path,
> to reduce the overhead during flow operations at the library level.
> Main source of the overhead was indirection and checks done while
> ethdev library was fetching rte_flow_ops from a given driver.
> 
> This patch introduces rte_flow_fp_ops struct which holds callbacks
> to driver's implementation of fast path async flow API functions.
> Each driver implementing these functions must populate flow_fp_ops
> field inside rte_eth_dev structure with a reference to
> its own implementation.
> By default, ethdev library provides dummy callbacks with
> implementations returning ENOSYS.
> Such design provides a few assumptions:
> 
> - rte_flow_fp_ops struct for given port is always available.
> - Each callback is either:
>     - Default provided by library.
>     - Set up by driver.
> 
> As a result, no checks for availability of the implementation
> are needed at library level in data path.
> Any library-level validation checks in async flow API are compiled
> if and only if RTE_FLOW_DEBUG macro is defined.
> 
> These changes apply only to the following API functions:
> 
> - rte_flow_async_create()
> - rte_flow_async_create_by_index()
> - rte_flow_async_actions_update()
> - rte_flow_async_destroy()
> - rte_flow_push()
> - rte_flow_pull()
> - rte_flow_async_action_handle_create()
> - rte_flow_async_action_handle_destroy()
> - rte_flow_async_action_handle_update()
> - rte_flow_async_action_handle_query()
> - rte_flow_async_action_handle_query_update()
> - rte_flow_async_action_list_handle_create()
> - rte_flow_async_action_list_handle_destroy()
> - rte_flow_async_action_list_handle_query_update()
> 
> This patch also adjusts the mlx5 PMD to the introduced flow API changes.
> 
> Signed-off-by: Dariusz Sosnowski <dsosnowski at nvidia.com>
> ---
> v2:
> - Fixed mlx5 PMD build issue with older versions of rdma-core.
> ---

Acked-by: Ori Kam <orika at nvidia.com>
Best,
Ori