From: Shay Drory shayd@nvidia.com
[ Upstream commit 16d42d313350946f4b9a8b74a13c99f0461a6572 ]
In case fw sync reset is called in parallel to device removal, device might stuck in the following deadlock: CPU 0 CPU 1 ----- ----- remove_one uninit_one (locks intf_state_mutex) mlx5_sync_reset_now_event() work in fw_reset->wq. mlx5_enter_error_state() mutex_lock (intf_state_mutex) cleanup_once fw_reset_cleanup() destroy_workqueue(fw_reset->wq)
Drain the fw_reset WQ, and make sure no new work is being queued, before entering uninit_one(). The Drain is done before devlink_unregister() since fw_reset, in some flows, is using devlink API devlink_remote_reload_actions_performed().
Fixes: 38b9f903f22b ("net/mlx5: Handle sync reset request event") Signed-off-by: Shay Drory shayd@nvidia.com Reviewed-by: Moshe Shemesh moshe@nvidia.com Signed-off-by: Saeed Mahameed saeedm@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- .../ethernet/mellanox/mlx5/core/fw_reset.c | 25 ++++++++++++++++--- .../ethernet/mellanox/mlx5/core/fw_reset.h | 1 + .../net/ethernet/mellanox/mlx5/core/main.c | 4 +++ 3 files changed, 27 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c index 862f5b7cb210..1c771287bee5 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c @@ -8,7 +8,8 @@ enum { MLX5_FW_RESET_FLAGS_RESET_REQUESTED, MLX5_FW_RESET_FLAGS_NACK_RESET_REQUEST, - MLX5_FW_RESET_FLAGS_PENDING_COMP + MLX5_FW_RESET_FLAGS_PENDING_COMP, + MLX5_FW_RESET_FLAGS_DROP_NEW_REQUESTS };
struct mlx5_fw_reset { @@ -165,7 +166,10 @@ static void poll_sync_reset(struct timer_list *t)
if (fatal_error) { mlx5_core_warn(dev, "Got Device Reset\n"); - queue_work(fw_reset->wq, &fw_reset->reset_reload_work); + if (!test_bit(MLX5_FW_RESET_FLAGS_DROP_NEW_REQUESTS, &fw_reset->reset_flags)) + queue_work(fw_reset->wq, &fw_reset->reset_reload_work); + else + mlx5_core_err(dev, "Device is being removed, Drop new reset work\n"); return; }
@@ -390,9 +394,12 @@ static int fw_reset_event_notifier(struct notifier_block *nb, unsigned long acti struct mlx5_fw_reset *fw_reset = mlx5_nb_cof(nb, struct mlx5_fw_reset, nb); struct mlx5_eqe *eqe = data;
+ if (test_bit(MLX5_FW_RESET_FLAGS_DROP_NEW_REQUESTS, &fw_reset->reset_flags)) + return NOTIFY_DONE; + switch (eqe->sub_type) { case MLX5_GENERAL_SUBTYPE_FW_LIVE_PATCH_EVENT: - queue_work(fw_reset->wq, &fw_reset->fw_live_patch_work); + queue_work(fw_reset->wq, &fw_reset->fw_live_patch_work); break; case MLX5_GENERAL_SUBTYPE_PCI_SYNC_FOR_FW_UPDATE_EVENT: mlx5_sync_reset_events_handle(fw_reset, eqe); @@ -436,6 +443,18 @@ void mlx5_fw_reset_events_stop(struct mlx5_core_dev *dev) mlx5_eq_notifier_unregister(dev, &dev->priv.fw_reset->nb); }
+void mlx5_drain_fw_reset(struct mlx5_core_dev *dev) +{ + struct mlx5_fw_reset *fw_reset = dev->priv.fw_reset; + + set_bit(MLX5_FW_RESET_FLAGS_DROP_NEW_REQUESTS, &fw_reset->reset_flags); + cancel_work_sync(&fw_reset->fw_live_patch_work); + cancel_work_sync(&fw_reset->reset_request_work); + cancel_work_sync(&fw_reset->reset_reload_work); + cancel_work_sync(&fw_reset->reset_now_work); + cancel_work_sync(&fw_reset->reset_abort_work); +} + int mlx5_fw_reset_init(struct mlx5_core_dev *dev) { struct mlx5_fw_reset *fw_reset = kzalloc(sizeof(*fw_reset), GFP_KERNEL); diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.h b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.h index 7761ee5fc7d0..372046e173e7 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.h @@ -15,6 +15,7 @@ int mlx5_fw_reset_set_live_patch(struct mlx5_core_dev *dev); int mlx5_fw_reset_wait_reset_done(struct mlx5_core_dev *dev); void mlx5_fw_reset_events_start(struct mlx5_core_dev *dev); void mlx5_fw_reset_events_stop(struct mlx5_core_dev *dev); +void mlx5_drain_fw_reset(struct mlx5_core_dev *dev); int mlx5_fw_reset_init(struct mlx5_core_dev *dev); void mlx5_fw_reset_cleanup(struct mlx5_core_dev *dev);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c b/drivers/net/ethernet/mellanox/mlx5/core/main.c index f1437b6d4418..4e49dca94bc3 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c @@ -1628,6 +1628,10 @@ static void remove_one(struct pci_dev *pdev) struct mlx5_core_dev *dev = pci_get_drvdata(pdev); struct devlink *devlink = priv_to_devlink(dev);
+ /* mlx5_drain_fw_reset() is using devlink APIs. Hence, we must drain + * fw_reset before unregistering the devlink. + */ + mlx5_drain_fw_reset(dev); devlink_unregister(devlink); mlx5_crdump_disable(dev); mlx5_drain_health_wq(dev);