IB/mthca: Annotate CQ locking
mthca_ib_lock_cqs()/mthca_ib_unlock_cqs() are helper functions that
lock/unlock both CQs attached to a QP in the proper order to avoid
AB-BA deadlocks. Annotate this so sparse can understand what's going
on (and warn us if we misuse these functions).
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/mthca/mthca_qp.c b/drivers/infiniband/hw/mthca/mthca_qp.c
index f5081bf..c10576f 100644
--- a/drivers/infiniband/hw/mthca/mthca_qp.c
+++ b/drivers/infiniband/hw/mthca/mthca_qp.c
@@ -1319,10 +1319,12 @@
}
static void mthca_lock_cqs(struct mthca_cq *send_cq, struct mthca_cq *recv_cq)
+ __acquires(&send_cq->lock) __acquires(&recv_cq->lock)
{
- if (send_cq == recv_cq)
+ if (send_cq == recv_cq) {
spin_lock_irq(&send_cq->lock);
- else if (send_cq->cqn < recv_cq->cqn) {
+ __acquire(&recv_cq->lock);
+ } else if (send_cq->cqn < recv_cq->cqn) {
spin_lock_irq(&send_cq->lock);
spin_lock_nested(&recv_cq->lock, SINGLE_DEPTH_NESTING);
} else {
@@ -1332,10 +1334,12 @@
}
static void mthca_unlock_cqs(struct mthca_cq *send_cq, struct mthca_cq *recv_cq)
+ __releases(&send_cq->lock) __releases(&recv_cq->lock)
{
- if (send_cq == recv_cq)
+ if (send_cq == recv_cq) {
+ __release(&recv_cq->lock);
spin_unlock_irq(&send_cq->lock);
- else if (send_cq->cqn < recv_cq->cqn) {
+ } else if (send_cq->cqn < recv_cq->cqn) {
spin_unlock(&recv_cq->lock);
spin_unlock_irq(&send_cq->lock);
} else {
