Re: [dpdk-dev] [PATCH v25 2/6] dmadev: add control plane API support

[Thomas Monjalon <thomas@monjalon.net>]

11/10/2021 09:33, Chengwen Feng:
> +Device Configuration
> +~~~~~~~~~~~~~~~~~~~~
> +
> +The rte_dma_configure API is used to configure a DMA device.
> +
> +.. code-block:: c
> +
> +   int rte_dma_configure(int16_t dev_id,
> +                         const struct rte_dma_conf *dev_conf);
> +
> +The ``rte_dma_conf`` structure is used to pass the configuration parameters
> +for the DMA device.
> +
> +
> +Configuration of Virtual DMA Channels
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +The rte_dma_vchan_setup API is used to configure a virtual DMA channel.
> +
> +.. code-block:: c
> +
> +   int rte_dma_vchan_setup(int16_t dev_id, uint16_t vchan,
> +                           const struct rte_dma_vchan_conf *conf);
> +
> +The ``rte_dma_vchan_conf`` structure is used to pass the configuration
> +parameters for the virtual DMA channel.

I think those 2 above sections don't bring anything in the guide.
Functions are described in Doxygen comments, it is enough.


> --- a/doc/guides/rel_notes/release_21_11.rst
> +++ b/doc/guides/rel_notes/release_21_11.rst
> @@ -144,6 +144,7 @@ New Features
>  * **Introduced dmadev library with:**
>  
>    * Device allocation functions.
> +  * Control plane API.

This is not a feature, you can drop from the release notes.


[...]
> +/**@{@name DMA capability
> + * @see struct rte_dma_info::dev_capa
> + */

Thank you for using Doxygen grouping.

> +#define RTE_DMA_CAPA_MEM_TO_MEM		RTE_BIT64(0)
> +/**< Support memory-to-memory transfer */

Would it be possible to put the comment before the flag?

> +#define RTE_DMA_CAPA_MEM_TO_DEV		RTE_BIT64(1)
> +/**< Support memory-to-device transfer. */
> +#define RTE_DMA_CAPA_DEV_TO_MEM		RTE_BIT64(2)
> +/**< Support device-to-memory transfer. */
> +#define RTE_DMA_CAPA_DEV_TO_DEV		RTE_BIT64(3)
> +/**< Support device-to-device transfer. */
> +#define RTE_DMA_CAPA_SVA		RTE_BIT64(4)
> +/**< Support SVA which could use VA as DMA address.
> + * If device support SVA then application could pass any VA address like memory
> + * from rte_malloc(), rte_memzone(), malloc, stack memory.
> + * If device don't support SVA, then application should pass IOVA address which
> + * from rte_malloc(), rte_memzone().
> + */
> +#define RTE_DMA_CAPA_SILENT		RTE_BIT64(5)
> +/**< Support work in silent mode.
> + * In this mode, application don't required to invoke rte_dma_completed*()
> + * API.
> + * @see struct rte_dma_conf::silent_mode
> + */
> +#define RTE_DMA_CAPA_OPS_COPY		RTE_BIT64(32)
> +/**< Support copy operation.
> + * This capability start with index of 32, so that it could leave gap between
> + * normal capability and ops capability.
> + */
> +#define RTE_DMA_CAPA_OPS_COPY_SG	RTE_BIT64(33)
> +/**< Support scatter-gather list copy operation. */
> +#define RTE_DMA_CAPA_OPS_FILL		RTE_BIT64(34)
> +/**< Support fill operation. */
> +/**@}*/