Re: [PATCH rdma-core 1/7] libhns: Fix calculation errors with ilog32()

[Weihang Li <liweihang@hisilicon.com>]

On 2019/11/22 10:58, Zengtao (B) wrote:
>> -----Original Message-----
>> From: linux-rdma-owner@vger.kernel.org
>> [mailto:linux-rdma-owner@vger.kernel.org] On Behalf Of Weihang Li
>> Sent: Thursday, November 21, 2019 9:19 AM
>> To: jgg@ziepe.ca; leon@kernel.org
>> Cc: dledford@redhat.com; linux-rdma@vger.kernel.org; Linuxarm
>> Subject: [PATCH rdma-core 1/7] libhns: Fix calculation errors with ilog32()
>>
>> Current calculation results using ilog32() is larger than expected, which
>> will lead to driver broken. The following is the log when QP creations
>> fails:
>>
>> [   81.294844] hns3 0000:7d:00.0 hns_0: check SQ size error!
>> [   81.294848] hns3 0000:7d:00.0 hns_0: check SQ size error!
>> [   81.300225] hns3 0000:7d:00.0 hns_0: Sanity check sq size failed
>> [   81.300227] hns3 0000:7d:00.0: hns_roce_set_user_sq_size error for
>> create qp
>> [   81.305602] hns3 0000:7d:00.0 hns_0: Sanity check sq size failed
>> [   81.305603] hns3 0000:7d:00.0: hns_roce_set_user_sq_size error for
>> create qp
>> [   81.311589] hns3 0000:7d:00.0 hns_0: Create RC QP 0x000000
>> failed(-22)
>> [   81.318603] hns3 0000:7d:00.0 hns_0: Create RC QP 0x000000
>> failed(-22)
>>
>> Fixes: b6cd213b276f ("libhns: Refactor for creating qp")
>> Signed-off-by: Weihang Li <liweihang@hisilicon.com>
>> ---
>>  providers/hns/hns_roce_u_verbs.c | 11 ++++++-----
>>  1 file changed, 6 insertions(+), 5 deletions(-)
>>
>> diff --git a/providers/hns/hns_roce_u_verbs.c
>> b/providers/hns/hns_roce_u_verbs.c
>> index 9d222c0..bd5060d 100644
>> --- a/providers/hns/hns_roce_u_verbs.c
>> +++ b/providers/hns/hns_roce_u_verbs.c
>> @@ -645,7 +645,8 @@ static int hns_roce_calc_qp_buff_size(struct
>> ibv_pd *pd, struct ibv_qp_cap *cap,
>>  	int page_size = to_hr_dev(pd->context->device)->page_size;
>>
>>  	if (to_hr_dev(pd->context->device)->hw_version ==
>> HNS_ROCE_HW_VER1) {
>> -		qp->rq.wqe_shift = ilog32(sizeof(struct hns_roce_rc_rq_wqe));
>> +		qp->rq.wqe_shift =
>> +				ilog32(sizeof(struct hns_roce_rc_rq_wqe)) - 1;
>>
>>  		qp->buf_size = align((qp->sq.wqe_cnt << qp->sq.wqe_shift),
>>  				     page_size) +
>> @@ -662,7 +663,7 @@ static int hns_roce_calc_qp_buff_size(struct
>> ibv_pd *pd, struct ibv_qp_cap *cap,
>>  	} else {
>>  		unsigned int rqwqe_size = HNS_ROCE_SGE_SIZE *
>> cap->max_recv_sge;
>>
>> -		qp->rq.wqe_shift = ilog32(rqwqe_size);
>> +		qp->rq.wqe_shift = ilog32(rqwqe_size) - 1;
>>
>>  		if (qp->sq.max_gs > HNS_ROCE_SGE_IN_WQE || type ==
>> IBV_QPT_UD)
>>  			qp->sge.sge_shift = HNS_ROCE_SGE_SHIFT;
>> @@ -747,8 +748,8 @@ static void hns_roce_set_qp_params(struct
>> ibv_pd *pd,
>>  		qp->rq.wqe_cnt =
>> roundup_pow_of_two(attr->cap.max_recv_wr);
>>  	}
>>
>> -	qp->sq.wqe_shift = ilog32(sizeof(struct hns_roce_rc_send_wqe));
>> -	qp->sq.shift = ilog32(qp->sq.wqe_cnt);
>> +	qp->sq.wqe_shift = ilog32(sizeof(struct hns_roce_rc_send_wqe)) - 1;
>> +	qp->sq.shift = ilog32(qp->sq.wqe_cnt) - 1;
> 
> One suggestion, it's better to introduce a new micro instead of ilog32(x) -1.

OK, thank you for your advice.

Weihang

> 
>>  	qp->rq.max_gs = attr->cap.max_recv_sge;
>>
>>  	if (to_hr_dev(pd->context->device)->hw_version ==
>> HNS_ROCE_HW_VER1) {
>> @@ -884,7 +885,7 @@ struct ibv_qp *hns_roce_u_create_qp(struct
>> ibv_pd *pd,
>>
>>  	cmd.buf_addr = (uintptr_t) qp->buf.buf;
>>  	cmd.log_sq_stride = qp->sq.wqe_shift;
>> -	cmd.log_sq_bb_count = ilog32(qp->sq.wqe_cnt);
>> +	cmd.log_sq_bb_count = ilog32(qp->sq.wqe_cnt) - 1;
>>
>>  	pthread_mutex_lock(&context->qp_table_mutex);
>>
>> --
>> 2.8.1
> 
> 
> .
>