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| author | Daniel Jurgens <danielj@mellanox.com> | 2018-01-04 17:25:31 +0200 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2018-01-08 11:42:20 -0700 |
| commit | 734dc065fc41f6143ff88225aa5d335cb1e0f6aa (patch) | |
| tree | 4c6bd43972f743d469b5c9d1f875cc9bd6ca2a26 /drivers/net | |
| parent | 776a3906b692963586ee9952e64ed87fb4b401c6 (diff) | |
| download | linux-stable-734dc065fc41f6143ff88225aa5d335cb1e0f6aa.tar.gz linux-stable-734dc065fc41f6143ff88225aa5d335cb1e0f6aa.tar.bz2 linux-stable-734dc065fc41f6143ff88225aa5d335cb1e0f6aa.zip | |
net/mlx5: Fix race for multiple RoCE enable
There are two potential problems with the existing implementation.
1. Enable and disable can race after the atomic operations.
2. If a command fails the refcount is left in an inconsistent state.
Introduce a lock and perform error checking.
Fixes: a6f7d2aff623 ("net/mlx5: Add support for multiple RoCE enable")
Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx5/core/vport.c | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/vport.c b/drivers/net/ethernet/mellanox/mlx5/core/vport.c index d653b0025b13..916523103f16 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/vport.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/vport.c @@ -36,6 +36,9 @@ #include <linux/mlx5/vport.h> #include "mlx5_core.h" +/* Mutex to hold while enabling or disabling RoCE */ +static DEFINE_MUTEX(mlx5_roce_en_lock); + static int _mlx5_query_vport_state(struct mlx5_core_dev *mdev, u8 opmod, u16 vport, u32 *out, int outlen) { @@ -988,17 +991,35 @@ static int mlx5_nic_vport_update_roce_state(struct mlx5_core_dev *mdev, int mlx5_nic_vport_enable_roce(struct mlx5_core_dev *mdev) { - if (atomic_inc_return(&mdev->roce.roce_en) != 1) - return 0; - return mlx5_nic_vport_update_roce_state(mdev, MLX5_VPORT_ROCE_ENABLED); + int err = 0; + + mutex_lock(&mlx5_roce_en_lock); + if (!mdev->roce.roce_en) + err = mlx5_nic_vport_update_roce_state(mdev, MLX5_VPORT_ROCE_ENABLED); + + if (!err) + mdev->roce.roce_en++; + mutex_unlock(&mlx5_roce_en_lock); + + return err; } EXPORT_SYMBOL_GPL(mlx5_nic_vport_enable_roce); int mlx5_nic_vport_disable_roce(struct mlx5_core_dev *mdev) { - if (atomic_dec_return(&mdev->roce.roce_en) != 0) - return 0; - return mlx5_nic_vport_update_roce_state(mdev, MLX5_VPORT_ROCE_DISABLED); + int err = 0; + + mutex_lock(&mlx5_roce_en_lock); + if (mdev->roce.roce_en) { + mdev->roce.roce_en--; + if (mdev->roce.roce_en == 0) + err = mlx5_nic_vport_update_roce_state(mdev, MLX5_VPORT_ROCE_DISABLED); + + if (err) + mdev->roce.roce_en++; + } + mutex_unlock(&mlx5_roce_en_lock); + return err; } EXPORT_SYMBOL_GPL(mlx5_nic_vport_disable_roce); |