TmFIFO invokes virtqueue callbacks from its FIFO work item under spin_lock_irqsave(). The core's synchronize_rcu() fallback already covers those sections.
Implement synchronize_cbs() using the existing per-direction locks instead of waiting for an RCU grace period. fifo->spin_lock[0] covers the transmit callbacks, including the callback from the timeout handler. fifo->spin_lock[1] covers the receive callbacks. Take and release each lock in turn to synchronize with callbacks running under that lock. Assisted-by: LLM Signed-off-by: Karl Mehltretter <[email protected]> --- drivers/platform/mellanox/mlxbf-tmfifo.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/platform/mellanox/mlxbf-tmfifo.c b/drivers/platform/mellanox/mlxbf-tmfifo.c index 3c6408581373..664bec20a7ae 100644 --- a/drivers/platform/mellanox/mlxbf-tmfifo.c +++ b/drivers/platform/mellanox/mlxbf-tmfifo.c @@ -1135,6 +1135,20 @@ static void mlxbf_tmfifo_virtio_reset(struct virtio_device *vdev) tm_vdev->status = 0; } +/* Synchronize with callbacks running in the FIFO work item. */ +static void mlxbf_tmfifo_virtio_synchronize_cbs(struct virtio_device *vdev) +{ + struct mlxbf_tmfifo_vdev *tm_vdev = mlxbf_vdev_to_tmfifo(vdev); + struct mlxbf_tmfifo *fifo = tm_vdev->vrings[0].fifo; + unsigned long flags; + int i; + + for (i = 0; i < ARRAY_SIZE(fifo->spin_lock); i++) { + spin_lock_irqsave(&fifo->spin_lock[i], flags); + spin_unlock_irqrestore(&fifo->spin_lock[i], flags); + } +} + /* Read the value of a configuration field. */ static void mlxbf_tmfifo_virtio_get(struct virtio_device *vdev, unsigned int offset, @@ -1179,6 +1193,7 @@ static const struct virtio_config_ops mlxbf_tmfifo_virtio_config_ops = { .find_vqs = mlxbf_tmfifo_virtio_find_vqs, .del_vqs = mlxbf_tmfifo_virtio_del_vqs, .reset = mlxbf_tmfifo_virtio_reset, + .synchronize_cbs = mlxbf_tmfifo_virtio_synchronize_cbs, .set_status = mlxbf_tmfifo_virtio_set_status, .get_status = mlxbf_tmfifo_virtio_get_status, .get = mlxbf_tmfifo_virtio_get, -- 2.39.5 (Apple Git-154)
