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IB/mlx4: Annotate CQ locking

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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>
This commit is contained in:
Roland Dreier 2009-09-05 20:24:49 -07:00
parent ff149b2a16
commit 338a8fad27
1 changed files with 8 additions and 4 deletions
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12
drivers/infiniband/hw/mlx4/qp.c
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@ -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 {