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, 4 insertions, 4 deletions

diff --git a/drivers/infiniband/hw/cxgb3/iwch_provider.h b/drivers/infiniband/hw/cxgb3/iwch_provider.h
index 2e38ddefea8a..8adbe9658935 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_provider.h
+++ b/drivers/infiniband/hw/cxgb3/iwch_provider.h
@@ -326,10 +326,10 @@ enum iwch_qp_query_flags {
 };
 
 u16 iwch_rqes_posted(struct iwch_qp *qhp);
-int iwch_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
-		      struct ib_send_wr **bad_wr);
-int iwch_post_receive(struct ib_qp *ibqp, struct ib_recv_wr *wr,
-		      struct ib_recv_wr **bad_wr);
+int iwch_post_send(struct ib_qp *ibqp, const struct ib_send_wr *wr,
+		   const struct ib_send_wr **bad_wr);
+int iwch_post_receive(struct ib_qp *ibqp, const struct ib_recv_wr *wr,
+		      const struct ib_recv_wr **bad_wr);
 int iwch_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc);
 int iwch_post_terminate(struct iwch_qp *qhp, struct respQ_msg_t *rsp_msg);
 int iwch_post_zb_read(struct iwch_ep *ep);