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Commit 338a8fad authored by Roland Dreier's avatar Roland Dreier
Browse files

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: default avatarRoland Dreier <rolandd@cisco.com>
parent ff149b2a

drivers/infiniband/hw/mlx4/qp.c

+8 −4
Original line number Diff line number Diff line
@@ -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 {