| Message ID | 20230412015038.674023-4-kuba@kernel.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | None | expand |
On 12/04/2023 4:50, Jakub Kicinski wrote: > Eric points out that we should make sure that ring index updates > are wrapped in the appropriate READ_ONCE/WRITE_ONCE macros. > > Suggested-by: Eric Dumazet <edumazet@google.com> > Reviewed-by: Eric Dumazet <edumazet@google.com> > Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com> > Signed-off-by: Jakub Kicinski <kuba@kernel.org> > --- > CC: tariqt@nvidia.com > CC: linux-rdma@vger.kernel.org > --- > drivers/net/ethernet/mellanox/mlx4/en_tx.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > Reviewed-by: Tariq Toukan <tariqt@nvidia.com> Thanks!
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c index 2f79378fbf6e..65cb63f6c465 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c @@ -228,7 +228,9 @@ void mlx4_en_deactivate_tx_ring(struct mlx4_en_priv *priv, static inline bool mlx4_en_is_tx_ring_full(struct mlx4_en_tx_ring *ring) { - return ring->prod - ring->cons > ring->full_size; + u32 used = READ_ONCE(ring->prod) - READ_ONCE(ring->cons); + + return used > ring->full_size; } static void mlx4_en_stamp_wqe(struct mlx4_en_priv *priv, @@ -1083,7 +1085,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP); } - ring->prod += nr_txbb; + WRITE_ONCE(ring->prod, ring->prod + nr_txbb); /* If we used a bounce buffer then copy descriptor back into place */ if (unlikely(bounce)) @@ -1214,7 +1216,7 @@ netdev_tx_t mlx4_en_xmit_frame(struct mlx4_en_rx_ring *rx_ring, rx_ring->xdp_tx++; - ring->prod += MLX4_EN_XDP_TX_NRTXBB; + WRITE_ONCE(ring->prod, ring->prod + MLX4_EN_XDP_TX_NRTXBB); /* Ensure new descriptor hits memory * before setting ownership of this descriptor to HW