IB/qib: Remove qib_lookup_qpn and use rvt_lookup_qpn instead

Add calls to rcu_read_lock()/rcu_read_unlock() as rvt_lookup_qpn callers
must hold the rcu_read_lock before calling and keep the lock until the
returned qp is no longer in use.

Remove lookaside qp and some qp refcount atomics in the sdma send code
that is redundant with the s_dma_busy refcount, which will also stall
the state processing to the reset state.

Change the qpn hash function to hash_32 which is hash function used
in rvt_lookup_qpn. qpn_hash function would be eliminated in later patches.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 8 insertions, 17 deletions

diff --git a/drivers/infiniband/hw/qib/qib_driver.c b/drivers/infiniband/hw/qib/qib_driver.c
index a11de8e44e8b..707d789d0b67 100644
--- a/drivers/infiniband/hw/qib/qib_driver.c
+++ b/drivers/infiniband/hw/qib/qib_driver.c
@@ -322,6 +322,8 @@ static u32 qib_rcv_hdrerr(struct qib_ctxtdata *rcd, struct qib_pportdata *ppd,
 		struct qib_ib_header *hdr = (struct qib_ib_header *) rhdr;
 		struct qib_other_headers *ohdr = NULL;
 		struct qib_ibport *ibp = &ppd->ibport_data;
+		struct qib_devdata *dd = ppd->dd;
+		struct rvt_dev_info *rdi = &dd->verbs_dev.rdi;
 		struct rvt_qp *qp = NULL;
 		u32 tlen = qib_hdrget_length_in_bytes(rhf_addr);
 		u16 lid  = be16_to_cpu(hdr->lrh[1]);
@@ -366,9 +368,12 @@ static u32 qib_rcv_hdrerr(struct qib_ctxtdata *rcd, struct qib_pportdata *ppd,
 		if (qp_num != QIB_MULTICAST_QPN) {
 			int ruc_res;
 
-			qp = qib_lookup_qpn(ibp, qp_num);
-			if (!qp)
+			rcu_read_lock();
+			qp = rvt_lookup_qpn(rdi, &ibp->rvp, qp_num);
+			if (!qp) {
+				rcu_read_unlock();
 				goto drop;
+			}
 
 			/*
 			 * Handle only RC QPs - for other QP types drop error
@@ -435,12 +440,7 @@ static u32 qib_rcv_hdrerr(struct qib_ctxtdata *rcd, struct qib_pportdata *ppd,
 
 unlock:
 			spin_unlock(&qp->r_lock);
-			/*
-			 * Notify qib_destroy_qp() if it is waiting
-			 * for us to finish.
-			 */
-			if (atomic_dec_and_test(&qp->refcount))
-				wake_up(&qp->wait);
+			rcu_read_unlock();
 		} /* Unicast QP */
 	} /* Valid packet with TIDErr */
 
@@ -565,15 +565,6 @@ move_along:
 			updegr = 0;
 		}
 	}
-	/*
-	 * Notify qib_destroy_qp() if it is waiting
-	 * for lookaside_qp to finish.
-	 */
-	if (rcd->lookaside_qp) {
-		if (atomic_dec_and_test(&rcd->lookaside_qp->refcount))
-			wake_up(&rcd->lookaside_qp->wait);
-		rcd->lookaside_qp = NULL;
-	}
 
 	rcd->head = l;