RDMA/hns: Add check for the validity of sl configuration

According to the RoCE v1 specification, the sl (service level) 0-7 are
mapped directly to priorities 0-7 respectively, sl 8-15 are reserved. The
driver should verify whether the the value of sl is larger than 7, if so,
an exception should be returned.

Fixes: 926a01dc ("RDMA/hns: Add QP operations support for hip08 SoC")
Link: https://lore.kernel.org/r/1600509802-44382-5-git-send-email-liweihang@huawei.comSigned-off-by: Jiaran Zhang <zhangjiaran@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

@@ -4372,11 +4372,19 @@ static int hns_roce_v2_set_path(struct ib_qp *ibqp,
 		       V2_QPC_BYTE_28_FL_S, 0);
 	memcpy(context->dgid, grh->dgid.raw, sizeof(grh->dgid.raw));
 	memset(qpc_mask->dgid, 0, sizeof(grh->dgid.raw));
+
+	hr_qp->sl = rdma_ah_get_sl(&attr->ah_attr);
+	if (unlikely(hr_qp->sl > MAX_SERVICE_LEVEL)) {
+		ibdev_err(ibdev,
+			  "failed to fill QPC, sl (%d) shouldn't be larger than %d.\n",
+			  hr_qp->sl, MAX_SERVICE_LEVEL);
+		return -EINVAL;
+	}
+
 	roce_set_field(context->byte_28_at_fl, V2_QPC_BYTE_28_SL_M,
-		       V2_QPC_BYTE_28_SL_S, rdma_ah_get_sl(&attr->ah_attr));
+		       V2_QPC_BYTE_28_SL_S, hr_qp->sl);
 	roce_set_field(qpc_mask->byte_28_at_fl, V2_QPC_BYTE_28_SL_M,
 		       V2_QPC_BYTE_28_SL_S, 0);
-	hr_qp->sl = rdma_ah_get_sl(&attr->ah_attr);
 
 	return 0;
 }

drivers/infiniband/hw/hns/hns_roce_hw_v2.h

@@ -1963,6 +1963,8 @@ struct hns_roce_eq_context {
 #define HNS_ROCE_V2_AEQE_EVENT_QUEUE_NUM_S 0
 #define HNS_ROCE_V2_AEQE_EVENT_QUEUE_NUM_M GENMASK(23, 0)
 
+#define MAX_SERVICE_LEVEL 0x7
+
 struct hns_roce_wqe_atomic_seg {
 	__le64          fetchadd_swap_data;
 	__le64          cmp_data;