Driver implementation of the spec:
http://patches.dpdk.org/project/dpdk/patch/20230907082443.1002665-1-amitpraka...@marvell.com/
> -----Original Message-----
> From: Amit Prakash Shukla <amitpraka...@marvell.com>
> Sent: Thursday, September 7, 2023 1:41 PM
> To: Chengwen Feng <fengcheng...@huawei.com>; Kevin Laatz
> <kevin.la...@intel.com>; Bruce Richardson <bruce.richard...@intel.com>
> Cc: dev@dpdk.org; Jerin Jacob Kollanukkaran <jer...@marvell.com>;
> conor.wa...@intel.com; Vamsi Krishna Attunuru <vattun...@marvell.com>;
> g.si...@nxp.com; sachin.sax...@oss.nxp.com; hemant.agra...@nxp.com;
> cheng1.ji...@intel.com; Nithin Kumar Dabilpuram
> <ndabilpu...@marvell.com>; Anoob Joseph <ano...@marvell.com>; Amit
> Prakash Shukla <amitpraka...@marvell.com>; Morten Brørup
> <m...@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 <amitpraka...@marvell.com>
> Acked-by: Morten Brørup <m...@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.
> + **/
> +#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
> 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.
> + *
> + * @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
