RDMA, core and ULPs: Declare ib_post_send() and ib_post_recv() arguments const

Since neither ib_post_send() nor ib_post_recv() modify the data structure
their second argument points at, declare that argument const. This change
makes it necessary to declare the 'bad_wr' argument const too and also to
modify all ULPs that call ib_post_send(), ib_post_recv() or
ib_post_srq_recv(). This patch does not change any functionality but makes
it possible for the compiler to verify whether the
ib_post_(send|recv|srq_recv) really do not modify the posted work request.

To make this possible, only one cast had to be introduce that casts away
constness, namely in rpcrdma_post_recvs(). The only way I can think of to
avoid that cast is to introduce an additional loop in that function or to
change the data type of bad_wr from struct ib_recv_wr ** into int
(an index that refers to an element in the work request list). However,
both approaches would require even more extensive changes than this
patch.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

4 files changed, 25 insertions, 25 deletions

diff --git a/drivers/infiniband/hw/qedr/qedr_roce_cm.c b/drivers/infiniband/hw/qedr/qedr_roce_cm.c
index b5d49740bf8a..85578887421b 100644
--- a/drivers/infiniband/hw/qedr/qedr_roce_cm.c
+++ b/drivers/infiniband/hw/qedr/qedr_roce_cm.c
@@ -537,8 +537,8 @@ static inline int qedr_gsi_build_packet(struct qedr_dev *dev,
 	return 0;
 }
 
-int qedr_gsi_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
-		       struct ib_send_wr **bad_wr)
+int qedr_gsi_post_send(struct ib_qp *ibqp, const struct ib_send_wr *wr,
+		       const struct ib_send_wr **bad_wr)
 {
 	struct qed_roce_ll2_packet *pkt = NULL;
 	struct qedr_qp *qp = get_qedr_qp(ibqp);
@@ -607,8 +607,8 @@ err:
 	return rc;
 }
 
-int qedr_gsi_post_recv(struct ib_qp *ibqp, struct ib_recv_wr *wr,
-		       struct ib_recv_wr **bad_wr)
+int qedr_gsi_post_recv(struct ib_qp *ibqp, const struct ib_recv_wr *wr,
+		       const struct ib_recv_wr **bad_wr)
 {
 	struct qedr_dev *dev = get_qedr_dev(ibqp->device);
 	struct qedr_qp *qp = get_qedr_qp(ibqp);
diff --git a/drivers/infiniband/hw/qedr/qedr_roce_cm.h b/drivers/infiniband/hw/qedr/qedr_roce_cm.h
index a55916323ea9..d46dcd3f6424 100644
--- a/drivers/infiniband/hw/qedr/qedr_roce_cm.h
+++ b/drivers/infiniband/hw/qedr/qedr_roce_cm.h
@@ -46,10 +46,10 @@ static inline u32 qedr_get_ipv4_from_gid(const u8 *gid)
 
 /* RDMA CM */
 int qedr_gsi_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc);
-int qedr_gsi_post_recv(struct ib_qp *ibqp, struct ib_recv_wr *wr,
-		       struct ib_recv_wr **bad_wr);
-int qedr_gsi_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
-		       struct ib_send_wr **bad_wr);
+int qedr_gsi_post_recv(struct ib_qp *ibqp, const struct ib_recv_wr *wr,
+		       const struct ib_recv_wr **bad_wr);
+int qedr_gsi_post_send(struct ib_qp *ibqp, const struct ib_send_wr *wr,
+		       const struct ib_send_wr **bad_wr);
 struct ib_qp *qedr_create_gsi_qp(struct qedr_dev *dev,
 				 struct ib_qp_init_attr *attrs,
 				 struct qedr_qp *qp);
diff --git a/drivers/infiniband/hw/qedr/verbs.c b/drivers/infiniband/hw/qedr/verbs.c
index 34d8b5580138..4aaeb24cebfc 100644
--- a/drivers/infiniband/hw/qedr/verbs.c
+++ b/drivers/infiniband/hw/qedr/verbs.c
@@ -2696,9 +2696,9 @@ static void swap_wqe_data64(u64 *p)
 
 static u32 qedr_prepare_sq_inline_data(struct qedr_dev *dev,
 				       struct qedr_qp *qp, u8 *wqe_size,
-				       struct ib_send_wr *wr,
-				       struct ib_send_wr **bad_wr, u8 *bits,
-				       u8 bit)
+				       const struct ib_send_wr *wr,
+				       const struct ib_send_wr **bad_wr,
+				       u8 *bits, u8 bit)
 {
 	u32 data_size = sge_data_len(wr->sg_list, wr->num_sge);
 	char *seg_prt, *wqe;
@@ -2805,8 +2805,8 @@ static u32 qedr_prepare_sq_rdma_data(struct qedr_dev *dev,
 				     struct qedr_qp *qp,
 				     struct rdma_sq_rdma_wqe_1st *rwqe,
 				     struct rdma_sq_rdma_wqe_2nd *rwqe2,
-				     struct ib_send_wr *wr,
-				     struct ib_send_wr **bad_wr)
+				     const struct ib_send_wr *wr,
+				     const struct ib_send_wr **bad_wr)
 {
 	rwqe2->r_key = cpu_to_le32(rdma_wr(wr)->rkey);
 	DMA_REGPAIR_LE(rwqe2->remote_va, rdma_wr(wr)->remote_addr);
@@ -2828,8 +2828,8 @@ static u32 qedr_prepare_sq_send_data(struct qedr_dev *dev,
 				     struct qedr_qp *qp,
 				     struct rdma_sq_send_wqe_1st *swqe,
 				     struct rdma_sq_send_wqe_2st *swqe2,
-				     struct ib_send_wr *wr,
-				     struct ib_send_wr **bad_wr)
+				     const struct ib_send_wr *wr,
+				     const struct ib_send_wr **bad_wr)
 {
 	memset(swqe2, 0, sizeof(*swqe2));
 	if (wr->send_flags & IB_SEND_INLINE) {
@@ -2945,8 +2945,8 @@ static inline bool qedr_can_post_send(struct qedr_qp *qp,
 	return true;
 }
 
-static int __qedr_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
-		     struct ib_send_wr **bad_wr)
+static int __qedr_post_send(struct ib_qp *ibqp, const struct ib_send_wr *wr,
+			    const struct ib_send_wr **bad_wr)
 {
 	struct qedr_dev *dev = get_qedr_dev(ibqp->device);
 	struct qedr_qp *qp = get_qedr_qp(ibqp);
@@ -3160,8 +3160,8 @@ static int __qedr_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
 	return rc;
 }
 
-int qedr_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
-		   struct ib_send_wr **bad_wr)
+int qedr_post_send(struct ib_qp *ibqp, const struct ib_send_wr *wr,
+		   const struct ib_send_wr **bad_wr)
 {
 	struct qedr_dev *dev = get_qedr_dev(ibqp->device);
 	struct qedr_qp *qp = get_qedr_qp(ibqp);
@@ -3226,8 +3226,8 @@ int qedr_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
 	return rc;
 }
 
-int qedr_post_recv(struct ib_qp *ibqp, struct ib_recv_wr *wr,
-		   struct ib_recv_wr **bad_wr)
+int qedr_post_recv(struct ib_qp *ibqp, const struct ib_recv_wr *wr,
+		   const struct ib_recv_wr **bad_wr)
 {
 	struct qedr_qp *qp = get_qedr_qp(ibqp);
 	struct qedr_dev *dev = qp->dev;
diff --git a/drivers/infiniband/hw/qedr/verbs.h b/drivers/infiniband/hw/qedr/verbs.h
index 2c57e4c592a6..087baf009864 100644
--- a/drivers/infiniband/hw/qedr/verbs.h
+++ b/drivers/infiniband/hw/qedr/verbs.h
@@ -82,10 +82,10 @@ int qedr_map_mr_sg(struct ib_mr *ibmr, struct scatterlist *sg,
 struct ib_mr *qedr_alloc_mr(struct ib_pd *pd, enum ib_mr_type mr_type,
 			    u32 max_num_sg);
 int qedr_poll_cq(struct ib_cq *, int num_entries, struct ib_wc *wc);
-int qedr_post_send(struct ib_qp *, struct ib_send_wr *,
-		   struct ib_send_wr **bad_wr);
-int qedr_post_recv(struct ib_qp *, struct ib_recv_wr *,
-		   struct ib_recv_wr **bad_wr);
+int qedr_post_send(struct ib_qp *, const struct ib_send_wr *,
+		   const struct ib_send_wr **bad_wr);
+int qedr_post_recv(struct ib_qp *, const struct ib_recv_wr *,
+		   const struct ib_recv_wr **bad_wr);
 int qedr_process_mad(struct ib_device *ibdev, int process_mad_flags,
 		     u8 port_num, const struct ib_wc *in_wc,
 		     const struct ib_grh *in_grh,