IB/mlx4: Annotate CQ locking
mlx4_ib_lock_cqs()/mlx4_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/mlx4/qp.c b/drivers/infiniband/hw/mlx4/qp.c
index c4a0264..219b103 100644
--- a/drivers/infiniband/hw/mlx4/qp.c
+++ b/drivers/infiniband/hw/mlx4/qp.c
@@ -615,10 +615,12 @@
}
static void mlx4_ib_lock_cqs(struct mlx4_ib_cq *send_cq, struct mlx4_ib_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->mcq.cqn < recv_cq->mcq.cqn) {
+ __acquire(&recv_cq->lock);
+ } else if (send_cq->mcq.cqn < recv_cq->mcq.cqn) {
spin_lock_irq(&send_cq->lock);
spin_lock_nested(&recv_cq->lock, SINGLE_DEPTH_NESTING);
} else {
@@ -628,10 +630,12 @@
}
static void mlx4_ib_unlock_cqs(struct mlx4_ib_cq *send_cq, struct mlx4_ib_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->mcq.cqn < recv_cq->mcq.cqn) {
+ } else if (send_cq->mcq.cqn < recv_cq->mcq.cqn) {
spin_unlock(&recv_cq->lock);
spin_unlock_irq(&send_cq->lock);
} else {