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>

2 files changed, 14 insertions, 14 deletions

diff --git a/drivers/infiniband/hw/bnxt_re/ib_verbs.c b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
index a0082e0bb8e2..5d955b293c6d 100644
--- a/drivers/infiniband/hw/bnxt_re/ib_verbs.c
+++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
@@ -1519,8 +1519,8 @@ int bnxt_re_query_srq(struct ib_srq *ib_srq, struct ib_srq_attr *srq_attr)
 	return 0;
 }
 
-int bnxt_re_post_srq_recv(struct ib_srq *ib_srq, struct ib_recv_wr *wr,
-			  struct ib_recv_wr **bad_wr)
+int bnxt_re_post_srq_recv(struct ib_srq *ib_srq, const struct ib_recv_wr *wr,
+			  const struct ib_recv_wr **bad_wr)
 {
 	struct bnxt_re_srq *srq = container_of(ib_srq, struct bnxt_re_srq,
 					       ib_srq);
@@ -2048,7 +2048,7 @@ static int bnxt_re_build_qp1_send_v2(struct bnxt_re_qp *qp,
  * and the MAD datagram out to the provided SGE.
  */
 static int bnxt_re_build_qp1_shadow_qp_recv(struct bnxt_re_qp *qp,
-					    struct ib_recv_wr *wr,
+					    const struct ib_recv_wr *wr,
 					    struct bnxt_qplib_swqe *wqe,
 					    int payload_size)
 {
@@ -2361,8 +2361,8 @@ bad:
 	return rc;
 }
 
-int bnxt_re_post_send(struct ib_qp *ib_qp, struct ib_send_wr *wr,
-		      struct ib_send_wr **bad_wr)
+int bnxt_re_post_send(struct ib_qp *ib_qp, const struct ib_send_wr *wr,
+		      const struct ib_send_wr **bad_wr)
 {
 	struct bnxt_re_qp *qp = container_of(ib_qp, struct bnxt_re_qp, ib_qp);
 	struct bnxt_qplib_swqe wqe;
@@ -2461,7 +2461,7 @@ bad:
 
 static int bnxt_re_post_recv_shadow_qp(struct bnxt_re_dev *rdev,
 				       struct bnxt_re_qp *qp,
-				       struct ib_recv_wr *wr)
+				       const struct ib_recv_wr *wr)
 {
 	struct bnxt_qplib_swqe wqe;
 	int rc = 0;
@@ -2494,8 +2494,8 @@ static int bnxt_re_post_recv_shadow_qp(struct bnxt_re_dev *rdev,
 	return rc;
 }
 
-int bnxt_re_post_recv(struct ib_qp *ib_qp, struct ib_recv_wr *wr,
-		      struct ib_recv_wr **bad_wr)
+int bnxt_re_post_recv(struct ib_qp *ib_qp, const struct ib_recv_wr *wr,
+		      const struct ib_recv_wr **bad_wr)
 {
 	struct bnxt_re_qp *qp = container_of(ib_qp, struct bnxt_re_qp, ib_qp);
 	struct bnxt_qplib_swqe wqe;
diff --git a/drivers/infiniband/hw/bnxt_re/ib_verbs.h b/drivers/infiniband/hw/bnxt_re/ib_verbs.h
index bd04d40d897a..aa33e7b82c84 100644
--- a/drivers/infiniband/hw/bnxt_re/ib_verbs.h
+++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.h
@@ -181,8 +181,8 @@ int bnxt_re_modify_srq(struct ib_srq *srq, struct ib_srq_attr *srq_attr,
 		       struct ib_udata *udata);
 int bnxt_re_query_srq(struct ib_srq *srq, struct ib_srq_attr *srq_attr);
 int bnxt_re_destroy_srq(struct ib_srq *srq);
-int bnxt_re_post_srq_recv(struct ib_srq *srq, struct ib_recv_wr *recv_wr,
-			  struct ib_recv_wr **bad_recv_wr);
+int bnxt_re_post_srq_recv(struct ib_srq *srq, const struct ib_recv_wr *recv_wr,
+			  const struct ib_recv_wr **bad_recv_wr);
 struct ib_qp *bnxt_re_create_qp(struct ib_pd *pd,
 				struct ib_qp_init_attr *qp_init_attr,
 				struct ib_udata *udata);
@@ -191,10 +191,10 @@ int bnxt_re_modify_qp(struct ib_qp *qp, struct ib_qp_attr *qp_attr,
 int bnxt_re_query_qp(struct ib_qp *qp, struct ib_qp_attr *qp_attr,
 		     int qp_attr_mask, struct ib_qp_init_attr *qp_init_attr);
 int bnxt_re_destroy_qp(struct ib_qp *qp);
-int bnxt_re_post_send(struct ib_qp *qp, struct ib_send_wr *send_wr,
-		      struct ib_send_wr **bad_send_wr);
-int bnxt_re_post_recv(struct ib_qp *qp, struct ib_recv_wr *recv_wr,
-		      struct ib_recv_wr **bad_recv_wr);
+int bnxt_re_post_send(struct ib_qp *qp, const struct ib_send_wr *send_wr,
+		      const struct ib_send_wr **bad_send_wr);
+int bnxt_re_post_recv(struct ib_qp *qp, const struct ib_recv_wr *recv_wr,
+		      const struct ib_recv_wr **bad_recv_wr);
 struct ib_cq *bnxt_re_create_cq(struct ib_device *ibdev,
 				const struct ib_cq_init_attr *attr,
 				struct ib_ucontext *context,