Re: [dpdk-dev] [PATCH v2 4/4] dma/cnxk: add copy_sg function

[fengchengwen <fengchengwen@huawei.com>]

On 2021/11/2 11:40, Radha Mohan Chintakuntla wrote:
> Add the copy_sg function that will do the multiple DMA transfers of
> different sizes and different source/destination as well.
> 

...

>  
> +static int
> +cnxk_dmadev_copy_sg(void *dev_private, uint16_t vchan,
> +		    const struct rte_dma_sge *src,
> +		    const struct rte_dma_sge *dst,
> +		    uint16_t nb_src, uint16_t nb_dst, uint64_t flags)
> +{
> +	struct cnxk_dpi_vf_s *dpivf = dev_private;
> +	union dpi_instr_hdr_s *header = &dpivf->conf.hdr;
> +	const struct rte_dma_sge *fptr, *lptr;
> +	struct cnxk_dpi_compl_s *comp_ptr;
> +	int num_words = 0;
> +	int i, rc;
> +
> +	RTE_SET_USED(vchan);
> +
> +	comp_ptr = dpivf->conf.c_desc.compl_ptr[dpivf->conf.c_desc.tail];
> +	comp_ptr->cdata = DPI_REQ_CDATA;
> +	header->s.ptr = (uint64_t)comp_ptr;
> +	STRM_INC(dpivf->conf.c_desc);
> +
> +	/*
> +	 * For inbound case, src pointers are last pointers.
> +	 * For all other cases, src pointers are first pointers.
> +	 */
> +	if (header->s.xtype == DPI_XTYPE_INBOUND) {
> +		header->s.nfst = nb_dst & 0xf;
> +		header->s.nlst = nb_src & 0xf;
> +		fptr = &dst[0];
> +		lptr = &src[0];
> +	} else {
> +		header->s.nfst = nb_src & 0xf;
> +		header->s.nlst = nb_dst & 0xf;
> +		fptr = &src[0];
> +		lptr = &dst[0];
> +	}
> +
> +	dpivf->cmd[0] = header->u[0];
> +	dpivf->cmd[1] = header->u[1];
> +	dpivf->cmd[2] = header->u[2];
> +	num_words += 4;
> +	for (i = 0; i < header->s.nfst; i++) {
> +		dpivf->cmd[num_words++] = (uint64_t)fptr->length;
> +		dpivf->cmd[num_words++] = fptr->addr;
> +		fptr++;
> +	}
> +
> +	for (i = 0; i < header->s.nlst; i++) {
> +		dpivf->cmd[num_words++] = (uint64_t)lptr->length;
> +		dpivf->cmd[num_words++] = lptr->addr;
> +		lptr++;
> +	}
> +
> +	rc = __dpi_queue_write(&dpivf->rdpi, dpivf->cmd, num_words);
> +	if (!rc) {
> +		if (flags & RTE_DMA_OP_FLAG_SUBMIT) {
> +			rte_wmb();
> +			plt_write64(num_words,
> +				    dpivf->rdpi.rbase + DPI_VDMA_DBELL);
> +		}
> +		dpivf->num_words = num_words;
> +	}
> +
> +	return rc;

should return ring index which in [0, 0xffff]

> +}
> +
>  static uint16_t
>  cnxk_dmadev_completed(void *dev_private, uint16_t vchan, const uint16_t nb_cpls,
>  		      uint16_t *last_idx, bool *has_error)
> @@ -369,6 +434,7 @@ cnxk_dmadev_probe(struct rte_pci_driver *pci_drv __rte_unused,
>  	dmadev->dev_ops = &cnxk_dmadev_ops;
>  
>  	dmadev->fp_obj->copy = cnxk_dmadev_copy;
> +	dmadev->fp_obj->copy_sg = cnxk_dmadev_copy_sg;
>  	dmadev->fp_obj->submit = cnxk_dmadev_submit;
>  	dmadev->fp_obj->completed = cnxk_dmadev_completed;
>  	dmadev->fp_obj->completed_status = cnxk_dmadev_completed_status;
>