Re: [PATCH v2] RDMA/hns: fix return value in hns_roce_map_mr_sg

[Junxian Huang <huangjunxian6@hisilicon.com>]

On 2024/4/11 11:38, Zhengchao Shao wrote:
> As described in the ib_map_mr_sg function comment, it returns the number
> of sg elements that were mapped to the memory region. However,
> hns_roce_map_mr_sg returns the number of pages required for mapping the
> DMA area. Fix it.
> 
> Fixes: 9b2cf76c9f05 ("RDMA/hns: Optimize PBL buffer allocation process")
> Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>

Thanks,

Reviewed-by: Junxian Huang <huangjunxian6@hisilicon.com>

> ---
> v2: fix the return value and coding format issues
> ---
>  drivers/infiniband/hw/hns/hns_roce_mr.c | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/hns/hns_roce_mr.c b/drivers/infiniband/hw/hns/hns_roce_mr.c
> index 9e05b57a2d67..80c050d7d0ea 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_mr.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_mr.c
> @@ -441,18 +441,18 @@ int hns_roce_map_mr_sg(struct ib_mr *ibmr, struct scatterlist *sg, int sg_nents,
>  	struct ib_device *ibdev = &hr_dev->ib_dev;
>  	struct hns_roce_mr *mr = to_hr_mr(ibmr);
>  	struct hns_roce_mtr *mtr = &mr->pbl_mtr;
> -	int ret = 0;
> +	int ret, sg_num = 0;
>  
>  	mr->npages = 0;
>  	mr->page_list = kvcalloc(mr->pbl_mtr.hem_cfg.buf_pg_count,
>  				 sizeof(dma_addr_t), GFP_KERNEL);
>  	if (!mr->page_list)
> -		return ret;
> +		return sg_num;
>  
> -	ret = ib_sg_to_pages(ibmr, sg, sg_nents, sg_offset, hns_roce_set_page);
> -	if (ret < 1) {
> +	sg_num = ib_sg_to_pages(ibmr, sg, sg_nents, sg_offset, hns_roce_set_page);
> +	if (sg_num < 1) {
>  		ibdev_err(ibdev, "failed to store sg pages %u %u, cnt = %d.\n",
> -			  mr->npages, mr->pbl_mtr.hem_cfg.buf_pg_count, ret);
> +			  mr->npages, mr->pbl_mtr.hem_cfg.buf_pg_count, sg_num);
>  		goto err_page_list;
>  	}
>  
> @@ -463,17 +463,16 @@ int hns_roce_map_mr_sg(struct ib_mr *ibmr, struct scatterlist *sg, int sg_nents,
>  	ret = hns_roce_mtr_map(hr_dev, mtr, mr->page_list, mr->npages);
>  	if (ret) {
>  		ibdev_err(ibdev, "failed to map sg mtr, ret = %d.\n", ret);
> -		ret = 0;
> +		sg_num = 0;
>  	} else {
>  		mr->pbl_mtr.hem_cfg.buf_pg_shift = (u32)ilog2(ibmr->page_size);
> -		ret = mr->npages;
>  	}
>  
>  err_page_list:
>  	kvfree(mr->page_list);
>  	mr->page_list = NULL;
>  
> -	return ret;
> +	return sg_num;
>  }
>  
>  static void hns_roce_mw_free(struct hns_roce_dev *hr_dev,