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>

1 files changed, 12 insertions, 12 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_dev.h b/drivers/infiniband/hw/mthca/mthca_dev.h
index 5508afbf1c67..220a3e4717a3 100644
--- a/drivers/infiniband/hw/mthca/mthca_dev.h
+++ b/drivers/infiniband/hw/mthca/mthca_dev.h
@@ -519,10 +519,10 @@ int mthca_max_srq_sge(struct mthca_dev *dev);
 void mthca_srq_event(struct mthca_dev *dev, u32 srqn,
 		     enum ib_event_type event_type);
 void mthca_free_srq_wqe(struct mthca_srq *srq, u32 wqe_addr);
-int mthca_tavor_post_srq_recv(struct ib_srq *srq, struct ib_recv_wr *wr,
-			      struct ib_recv_wr **bad_wr);
-int mthca_arbel_post_srq_recv(struct ib_srq *srq, struct ib_recv_wr *wr,
-			      struct ib_recv_wr **bad_wr);
+int mthca_tavor_post_srq_recv(struct ib_srq *srq, const struct ib_recv_wr *wr,
+			      const struct ib_recv_wr **bad_wr);
+int mthca_arbel_post_srq_recv(struct ib_srq *srq, const struct ib_recv_wr *wr,
+			      const struct ib_recv_wr **bad_wr);
 
 void mthca_qp_event(struct mthca_dev *dev, u32 qpn,
 		    enum ib_event_type event_type);
@@ -530,14 +530,14 @@ int mthca_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *qp_attr, int qp_attr_m
 		   struct ib_qp_init_attr *qp_init_attr);
 int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask,
 		    struct ib_udata *udata);
-int mthca_tavor_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
-			  struct ib_send_wr **bad_wr);
-int mthca_tavor_post_receive(struct ib_qp *ibqp, struct ib_recv_wr *wr,
-			     struct ib_recv_wr **bad_wr);
-int mthca_arbel_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
-			  struct ib_send_wr **bad_wr);
-int mthca_arbel_post_receive(struct ib_qp *ibqp, struct ib_recv_wr *wr,
-			     struct ib_recv_wr **bad_wr);
+int mthca_tavor_post_send(struct ib_qp *ibqp, const struct ib_send_wr *wr,
+			  const struct ib_send_wr **bad_wr);
+int mthca_tavor_post_receive(struct ib_qp *ibqp, const struct ib_recv_wr *wr,
+			     const struct ib_recv_wr **bad_wr);
+int mthca_arbel_post_send(struct ib_qp *ibqp, const struct ib_send_wr *wr,
+			  const struct ib_send_wr **bad_wr);
+int mthca_arbel_post_receive(struct ib_qp *ibqp, const struct ib_recv_wr *wr,
+			     const struct ib_recv_wr **bad_wr);
 void mthca_free_err_wqe(struct mthca_dev *dev, struct mthca_qp *qp, int is_send,
 			int index, int *dbd, __be32 *new_wqe);
 int mthca_alloc_qp(struct mthca_dev *dev,