From fdfd723e99e6cb3ae3be890bd5a41042ece50057 Mon Sep 17 00:00:00 2001 From: Saeed Mahameed Date: Mon, 11 Feb 2019 16:27:02 -0800 Subject: [PATCH] net/mlx5e: XDP, fix redirect resources availability check MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit [ Upstream commit 407e17b1a69a51ba9a512a04342da56c1f931df4 ] Currently mlx5 driver creates xdp redirect hw queues unconditionally on netdevice open, This is great until someone starts redirecting XDP traffic via ndo_xdp_xmit on mlx5 device and changes the device configuration at the same time, this might cause crashes, since the other device's napi is not aware of the mlx5 state change (resources un-availability). To fix this we must synchronize with other devices napi's on the system. Added a new flag under mlx5e_priv to determine XDP TX resources are available, set/clear it up when necessary and use synchronize_rcu() when the flag is turned off, so other napi's are in-sync with it, before we actually cleanup the hw resources. The flag is tested prior to committing to transmit on mlx5e_xdp_xmit, and it is sufficient to determine if it safe to transmit or not. The other two internal flags (MLX5E_STATE_OPENED and MLX5E_SQ_STATE_ENABLED) become unnecessary. Thus, they are removed from data path. Fixes: 58b99ee3e3eb ("net/mlx5e: Add support for XDP_REDIRECT in device-out side") Reported-by: Toke Høiland-Jørgensen Reviewed-by: Tariq Toukan Signed-off-by: Saeed Mahameed Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/mellanox/mlx5/core/en.h | 1 + .../net/ethernet/mellanox/mlx5/core/en/xdp.c | 6 ++---- .../net/ethernet/mellanox/mlx5/core/en/xdp.h | 17 +++++++++++++++++ .../net/ethernet/mellanox/mlx5/core/en_main.c | 2 ++ 4 files changed, 22 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h index 16ceeb1b2c9d8..da52e60d4437c 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h @@ -633,6 +633,7 @@ enum { MLX5E_STATE_ASYNC_EVENTS_ENABLED, MLX5E_STATE_OPENED, MLX5E_STATE_DESTROYING, + MLX5E_STATE_XDP_TX_ENABLED, }; struct mlx5e_rqt { diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c index ad6d471d00dd4..4a33c9a7cac7e 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c @@ -262,7 +262,8 @@ int mlx5e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, int sq_num; int i; - if (unlikely(!test_bit(MLX5E_STATE_OPENED, &priv->state))) + /* this flag is sufficient, no need to test internal sq state */ + if (unlikely(!mlx5e_xdp_tx_is_enabled(priv))) return -ENETDOWN; if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) @@ -275,9 +276,6 @@ int mlx5e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, sq = &priv->channels.c[sq_num]->xdpsq; - if (unlikely(!test_bit(MLX5E_SQ_STATE_ENABLED, &sq->state))) - return -ENETDOWN; - for (i = 0; i < n; i++) { struct xdp_frame *xdpf = frames[i]; struct mlx5e_xdp_info xdpi; diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.h b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.h index 6dfab045925f0..4d096623178b9 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.h @@ -49,6 +49,23 @@ bool mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct mlx5e_xdp_info *xdpi); int mlx5e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, u32 flags); +static inline void mlx5e_xdp_tx_enable(struct mlx5e_priv *priv) +{ + set_bit(MLX5E_STATE_XDP_TX_ENABLED, &priv->state); +} + +static inline void mlx5e_xdp_tx_disable(struct mlx5e_priv *priv) +{ + clear_bit(MLX5E_STATE_XDP_TX_ENABLED, &priv->state); + /* let other device's napi(s) see our new state */ + synchronize_rcu(); +} + +static inline bool mlx5e_xdp_tx_is_enabled(struct mlx5e_priv *priv) +{ + return test_bit(MLX5E_STATE_XDP_TX_ENABLED, &priv->state); +} + static inline void mlx5e_xmit_xdp_doorbell(struct mlx5e_xdpsq *sq) { struct mlx5_wq_cyc *wq = &sq->wq; diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c index 944f21f99d437..637d59c01fe5c 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -2890,6 +2890,7 @@ void mlx5e_activate_priv_channels(struct mlx5e_priv *priv) mlx5e_build_tx2sq_maps(priv); mlx5e_activate_channels(&priv->channels); + mlx5e_xdp_tx_enable(priv); netif_tx_start_all_queues(priv->netdev); if (MLX5_ESWITCH_MANAGER(priv->mdev)) @@ -2911,6 +2912,7 @@ void mlx5e_deactivate_priv_channels(struct mlx5e_priv *priv) */ netif_tx_stop_all_queues(priv->netdev); netif_tx_disable(priv->netdev); + mlx5e_xdp_tx_disable(priv); mlx5e_deactivate_channels(&priv->channels); } -- 2.50.1