[PATCH v1 1/2] dmadev: offload to free source buffer

[Anoob Joseph]

Hi Amit,

Thanks for adding the feature. Please see inline.

With the mentioned fixes,

Acked-by: Anoob Joseph <anoobj at marvell.com>

Thanks,
Anoob

> -----Original Message-----
> From: Amit Prakash Shukla <amitprakashs at marvell.com>
> Sent: Thursday, September 7, 2023 1:41 PM
> To: Chengwen Feng <fengchengwen at huawei.com>; Kevin Laatz
> <kevin.laatz at intel.com>; Bruce Richardson <bruce.richardson at intel.com>
> Cc: dev at dpdk.org; Jerin Jacob Kollanukkaran <jerinj at marvell.com>;
> conor.walsh at intel.com; Vamsi Krishna Attunuru <vattunuru at marvell.com>;
> g.singh at nxp.com; sachin.saxena at oss.nxp.com; hemant.agrawal at nxp.com;
> cheng1.jiang at intel.com; Nithin Kumar Dabilpuram
> <ndabilpuram at marvell.com>; Anoob Joseph <anoobj at marvell.com>; Amit
> Prakash Shukla <amitprakashs at marvell.com>; Morten Brørup
> <mb at smartsharesystems.com>
> Subject: [PATCH v1 1/2] dmadev: offload to free source buffer
> 
> This changeset adds support in DMA library to free source DMA buffer by
> hardware. On a supported hardware, application can pass on the mempool
> information as part of vchan config when the DMA transfer direction is
> configured as RTE_DMA_DIR_MEM_TO_DEV.
> 
> Signed-off-by: Amit Prakash Shukla <amitprakashs at marvell.com>
> Acked-by: Morten Brørup <mb at smartsharesystems.com>
> ---
>  lib/dmadev/rte_dmadev.h | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/lib/dmadev/rte_dmadev.h b/lib/dmadev/rte_dmadev.h index
> b157ab7600..d6a685907f 100644
> --- a/lib/dmadev/rte_dmadev.h
> +++ b/lib/dmadev/rte_dmadev.h
> @@ -278,6 +278,13 @@ int16_t rte_dma_next_dev(int16_t start_dev_id);
>  #define RTE_DMA_CAPA_OPS_COPY_SG	RTE_BIT64(33)
>  /** Support fill operation. */
>  #define RTE_DMA_CAPA_OPS_FILL		RTE_BIT64(34)
> +/** Support for source buffer free for mem to dev transfer.
> + *
> + * @note Even though the DMA driver has this capability, it may not
> +support all
> + * mempool drivers. If the mempool is not supported by the DMA driver,
> + * rte_dma_vchan_setup() will fail.
> + **/

[Anoob] I think you can remove the note. It is mentioned below also, right? That should be sufficient I guess. Not a strong comment. You can decide.

> +#define RTE_DMA_CAPA_MEM_TO_DEV_SOURCE_BUFFER_FREE
> 	RTE_BIT64(35)
>  /**@}*/
> 
>  /**
> @@ -581,6 +588,19 @@ struct rte_dma_vchan_conf {
>  	 * @see struct rte_dma_port_param
>  	 */
>  	struct rte_dma_port_param dst_port;
> +	/** mempool from which source buffer is allocated. mempool info is

[Anoob] Mempool -> Mempool (in both places)

> used
> +	 * for freeing source buffer by hardware when configured direction is
> +	 * RTE_DMA_DIR_MEM_TO_DEV. To free the source buffer by
> hardware,
> +	 * RTE_DMA_OP_FLAG_FREE_SBUF must be set while calling
> rte_dma_copy and
> +	 * rte_dma_copy_sg().
> +	 *
> +	 * @note If the mempool is not supported by the DMA driver,
> +	 * rte_dma_vchan_setup() will fail.

[Anoob] "If the mempool is not supported by the DMA device, ..."

driver -> device.

> +	 *
> +	 * @see RTE_DMA_OP_FLAG_FREE_SBUF
> +	 */
> +	struct rte_mempool *mem_to_dev_src_buf_pool;
> +
>  };
> 
>  /**
> @@ -818,6 +838,13 @@ struct rte_dma_sge {
>   * capability bit for this, driver should not return error if this flag was set.
>   */
>  #define RTE_DMA_OP_FLAG_LLC     RTE_BIT64(2)
> +/** Mem to dev source buffer free flag.
> + * Used for freeing source DMA buffer by hardware when the transfer
> +direction is
> + * configured as RTE_DMA_DIR_MEM_TO_DEV.
> + *
> + * @see struct rte_dma_vchan_conf::mem_to_dev_src_buf_pool
> + */
> +#define RTE_DMA_OP_FLAG_FREE_SBUF	RTE_BIT64(3)
>  /**@}*/
> 
>  /**
> --
> 2.25.1