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authorRoland Dreier <rolandd@cisco.com>2009-09-05 20:24:49 -0700
committerRoland Dreier <rolandd@cisco.com>2009-09-05 20:24:49 -0700
commit338a8fad27908f64a0d249cc9f5c7d4ddb7e5684 (patch)
tree5033fb5dbf31c967af592a41da04065ed2493ddd
parentff149b2a168296c74763cb4a6e7054bdb0a426a1 (diff)
downloadop-kernel-dev-338a8fad27908f64a0d249cc9f5c7d4ddb7e5684.zip
op-kernel-dev-338a8fad27908f64a0d249cc9f5c7d4ddb7e5684.tar.gz
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>
-rw-r--r--drivers/infiniband/hw/mlx4/qp.c12
1 files 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 {
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