RDMA/hns: Bugfix for calculation of extended sge

[ Upstream commit d34895c ]

Page alignment is required when setting the number of extended sge
according to the hardware's achivement. If the space of needed extended
sge is greater than one page, the roundup_pow_of_two() can ensure
that. But if the needed extended sge isn't 0 and can not be filled in a
whole page, the driver should align it specifically.

Fixes: 54d6638 ("RDMA/hns: Optimize WQE buffer size calculating process")
Link: https://lore.kernel.org/r/1606558959-48510-3-git-send-email-liweihang@huawei.com
Signed-off-by: Yangyang Li <liyangyang20@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/infiniband/hw/hns/hns_roce_qp.c

@@ -432,7 +432,12 @@ static int set_extend_sge_param(struct hns_roce_dev *hr_dev, u32 sq_wqe_cnt,
 	}
 
 	hr_qp->sge.sge_shift = HNS_ROCE_SGE_SHIFT;
-	hr_qp->sge.sge_cnt = cnt;
+
+	/* If the number of extended sge is not zero, they MUST use the
+	 * space of HNS_HW_PAGE_SIZE at least.
+	 */
+	hr_qp->sge.sge_cnt = cnt ?
+			max(cnt, (u32)HNS_HW_PAGE_SIZE / HNS_ROCE_SGE_SIZE) : 0;
 
 	return 0;
 }