From 338a8fad27908f64a0d249cc9f5c7d4ddb7e5684 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Sat, 5 Sep 2009 20:24:49 -0700 Subject: [PATCH] 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 --- drivers/infiniband/hw/mlx4/qp.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) 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 enum mlx4_qp_state to_mlx4_state(enum ib_qp_state state) } 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_lock_cqs(struct mlx4_ib_cq *send_cq, struct mlx4_ib_cq *recv } 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 { -- 2.7.4