net/mlx5: Tide up state_lock and vport enabled flag usage (77b09430) · Commits · 戴 / test

When eswitch is disabled, vport event handler is unregistered. This unregistration already synchronizes with running EQ event handler in below code flow. mlx5_eswitch_disable() mlx5_eswitch_event_handlers_unregister() mlx5_eq_notifier_unregister() atomic_notifier_chain_unregister() synchronize_rcu() notifier_callchain eswitch_vport_event() queue_work() Additionally vport->enabled flag is set under state_lock during esw_enable_vport() but is not read under state_lock in (a) esw_disable_vport() and (b) under atomic context eswitch_vport_event(). It is also necessary to synchronize with already scheduled vport event. This is already achieved using below sequence. mlx5_eswitch_event_handlers_unregister() [..] flush_workqueue() Hence, (a) Remove vport->enabled check in eswitch_vport_event() which doesn't make any sense. (b) Remove redundant flush_workqueue() on every vport disable. (c) Keep esw_disable_vport() symmetric with esw_enable_vport() for state_lock. Signed-off-by:

Parav Pandit <parav@mellanox.com> Reviewed-by:

Vu Pham <vuhuong@mellanox.com> Signed-off-by:

Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/eswitch.c

+5 −9

Original line number	Diff line number	Diff line
		@@ -1750,18 +1750,16 @@ static void esw_disable_vport(struct mlx5_eswitch *esw,
		{
		u16 vport_num = vport->vport;

		mutex_lock(&esw->state_lock);
		if (!vport->enabled)
		return;
		goto done;

		esw_debug(esw->dev, "Disabling vport(%d)\n", vport_num);
		/* Mark this vport as disabled to discard new events */
		vport->enabled = false;

		/* Wait for current already scheduled events to complete */
		flush_workqueue(esw->work_queue);
		/* Disable events from this vport */
		arm_vport_context_events_cmd(esw->dev, vport->vport, 0);
		mutex_lock(&esw->state_lock);
		/* We don't assume VFs will cleanup after themselves.
		* Calling vport change handler while vport is disabled will cleanup
		* the vport resources.
		@@ -1780,6 +1778,8 @@ static void esw_disable_vport(struct mlx5_eswitch *esw,
		esw_legacy_vport_destroy_drop_counters(vport);
		}
		esw->enabled_vports--;

		done:
		mutex_unlock(&esw->state_lock);
		}

		@@ -1793,12 +1793,8 @@ static int eswitch_vport_event(struct notifier_block *nb,

		vport_num = be16_to_cpu(eqe->data.vport_change.vport_num);
		vport = mlx5_eswitch_get_vport(esw, vport_num);
		if (IS_ERR(vport))
		return NOTIFY_OK;

		if (vport->enabled)
		if (!IS_ERR(vport))
		queue_work(esw->work_queue, &vport->vport_change_handler);

		return NOTIFY_OK;
		}

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