From c5c504f4dc8c98a1c62d8cee2cf175097fb68ff9 Mon Sep 17 00:00:00 2001 From: Alaa Hleihel Date: Sun, 10 May 2020 15:03:55 -0400 Subject: [PATCH 078/312] [netdrv] net/mlx5: Tide up state_lock and vport enabled flag usage Message-id: <20200510150452.10307-31-ahleihel@redhat.com> Patchwork-id: 306654 Patchwork-instance: patchwork O-Subject: [RHEL8.3 BZ 1789380 v2 30/87] net/mlx5: Tide up state_lock and vport enabled flag usage Bugzilla: 1789380 RH-Acked-by: Kamal Heib RH-Acked-by: Jarod Wilson RH-Acked-by: Tony Camuso RH-Acked-by: Jonathan Toppins Bugzilla: http://bugzilla.redhat.com/1789380 Upstream: v5.5-rc1 commit 77b094305b1ba23e716bb34d3e33c8fe30a5f487 Author: Parav Pandit Date: Mon Oct 28 23:35:13 2019 +0000 net/mlx5: Tide up state_lock and vport enabled flag usage 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 Reviewed-by: Vu Pham Signed-off-by: Saeed Mahameed Signed-off-by: Alaa Hleihel Signed-off-by: Frantisek Hrbata --- drivers/net/ethernet/mellanox/mlx5/core/eswitch.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c index 54b5f290ab9d..8067667fd59e 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c @@ -1745,18 +1745,16 @@ 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. @@ -1775,6 +1773,8 @@ 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); } @@ -1788,12 +1788,8 @@ 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; } -- 2.13.6