[PATCH rdma-next 10/12] RDMA/mlx5: Reuse existed shift_overlow helper

[Leon Romanovsky]

From: Leon Romanovsky <leo...@mellanox.com>

Rewrite commit 002bf2282b2d ("RDMA/mlx5: Protect from shift operand
overflow") to reuse newly introduced shift_overflow() helper.

Signed-off-by: Leon Romanovsky <leo...@mellanox.com>
---
 drivers/infiniband/hw/mlx5/qp.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
index 8e40263fd40e..5471b57b873d 100644
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -259,13 +259,17 @@ static int set_rq_size(struct mlx5_ib_dev *dev, struct 
ib_qp_cap *cap,
                cap->max_recv_sge = 0;
        } else {
                if (ucmd) {
+                       size_t s;
+
                        qp->rq.wqe_cnt = ucmd->rq_wqe_count;
-                       if (ucmd->rq_wqe_shift > BITS_PER_BYTE * 
sizeof(ucmd->rq_wqe_shift))
+                       s = shift_overflow(1, ucmd->rq_wqe_shift);
+                       if (s == SIZE_MAX)
                                return -EINVAL;
                        qp->rq.wqe_shift = ucmd->rq_wqe_shift;
-                       if ((1 << qp->rq.wqe_shift) / sizeof(struct 
mlx5_wqe_data_seg) < qp->wq_sig)
+                       if (s / sizeof(struct mlx5_wqe_data_seg) < qp->wq_sig)
                                return -EINVAL;
-                       qp->rq.max_gs = (1 << qp->rq.wqe_shift) / sizeof(struct 
mlx5_wqe_data_seg) - qp->wq_sig;
+                       qp->rq.max_gs = s / sizeof(struct mlx5_wqe_data_seg) -
+                                       qp->wq_sig;
                        qp->rq.max_post = qp->rq.wqe_cnt;
                } else {
                        wqe_size = qp->wq_sig ? sizeof(struct 
mlx5_wqe_signature_seg) : 0;
-- 
2.14.4