RDMA/cxgb4: Make c4iw_poll_cq_one() easier to analyze

Introduce the function __c4iw_poll_cq_one() such that c4iw_poll_cq_one()
becomes easier to analyze for static source code analyzers. This patch
avoids that sparse reports the following:

drivers/infiniband/hw/cxgb4/cq.c:401:36: warning: context imbalance in 'c4iw_flush_hw_cq' - unexpected unlock
drivers/infiniband/hw/cxgb4/cq.c:824:9: warning: context imbalance in 'c4iw_poll_cq_one' - different lock contexts for basic block

Compile-tested only.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Steve Wise <swise@chelsio.com>
Acked-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/hw/cxgb4/cq.c b/drivers/infiniband/hw/cxgb4/cq.c
index 2be2e1a..a5280d8 100644 (file)
--- a/drivers/infiniband/hw/cxgb4/cq.c
+++ b/drivers/infiniband/hw/cxgb4/cq.c
@@ -668,43 +668,22 @@ skip_cqe:
        return ret;
 }
 
-/*
- * Get one cq entry from c4iw and map it to openib.
- *
- * Returns:
- *     0                       cqe returned
- *     -ENODATA                EMPTY;
- *     -EAGAIN                 caller must try again
- *     any other -errno        fatal error
- */
-static int c4iw_poll_cq_one(struct c4iw_cq *chp, struct ib_wc *wc)
+static int __c4iw_poll_cq_one(struct c4iw_cq *chp, struct c4iw_qp *qhp,
+                             struct ib_wc *wc)
 {
-       struct c4iw_qp *qhp = NULL;
-       struct t4_cqe uninitialized_var(cqe), *rd_cqe;
-       struct t4_wq *wq;
+       struct t4_cqe cqe;
+       struct t4_wq *wq = qhp ? &qhp->wq : NULL;
        u32 credit = 0;
        u8 cqe_flushed;
        u64 cookie = 0;
        int ret;
 
-       ret = t4_next_cqe(&chp->cq, &rd_cqe);
-
-       if (ret)
-               return ret;
-
-       qhp = get_qhp(chp->rhp, CQE_QPID(rd_cqe));
-       if (!qhp)
-               wq = NULL;
-       else {
-               spin_lock(&qhp->lock);
-               wq = &(qhp->wq);
-       }
        ret = poll_cq(wq, &(chp->cq), &cqe, &cqe_flushed, &cookie, &credit);
        if (ret)
                goto out;
 
        wc->wr_id = cookie;
-       wc->qp = &qhp->ibqp;
+       wc->qp = qhp ? &qhp->ibqp : NULL;
        wc->vendor_err = CQE_STATUS(&cqe);
        wc->wc_flags = 0;
 
@@ -819,8 +798,37 @@ static int c4iw_poll_cq_one(struct c4iw_cq *chp, struct ib_wc *wc)
                }
        }
 out:
-       if (wq)
+       return ret;
+}
+
+/*
+ * Get one cq entry from c4iw and map it to openib.
+ *
+ * Returns:
+ *     0                       cqe returned
+ *     -ENODATA                EMPTY;
+ *     -EAGAIN                 caller must try again
+ *     any other -errno        fatal error
+ */
+static int c4iw_poll_cq_one(struct c4iw_cq *chp, struct ib_wc *wc)
+{
+       struct c4iw_qp *qhp = NULL;
+       struct t4_cqe *rd_cqe;
+       int ret;
+
+       ret = t4_next_cqe(&chp->cq, &rd_cqe);
+
+       if (ret)
+               return ret;
+
+       qhp = get_qhp(chp->rhp, CQE_QPID(rd_cqe));
+       if (qhp) {
+               spin_lock(&qhp->lock);
+               ret = __c4iw_poll_cq_one(chp, qhp, wc);
                spin_unlock(&qhp->lock);
+       } else {
+               ret = __c4iw_poll_cq_one(chp, NULL, wc);
+       }
        return ret;
 }