[PATCH 5.11 116/254] net/mlx5e: When changing XDP program without reset, take refs for XSK RQs

From: Greg Kroah-Hartman
Date: Mon Mar 29 2021 - 04:57:25 EST


From: Maxim Mikityanskiy <maximmi@xxxxxxxxxxxx>

[ Upstream commit e5eb01344e9b09bb9d255b9727449186f7168df8 ]

Each RQ (including XSK RQs) takes a reference to the XDP program. When
an XDP program is attached or detached, the channels and queues are
recreated, however, there is a special flow for changing an active XDP
program to another one. In that flow, channels and queues stay alive,
but the refcounts of the old and new XDP programs are adjusted. This
flow didn't increment refcount by the number of active XSK RQs, and this
commit fixes it.

Fixes: db05815b36cb ("net/mlx5e: Add XSK zero-copy support")
Signed-off-by: Maxim Mikityanskiy <maximmi@xxxxxxxxxxxx>
Reviewed-by: Tariq Toukan <tariqt@xxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 3248741af440..1386212ad3f0 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -4550,8 +4550,10 @@ static int mlx5e_xdp_set(struct net_device *netdev, struct bpf_prog *prog)
struct mlx5e_channel *c = priv->channels.c[i];

mlx5e_rq_replace_xdp_prog(&c->rq, prog);
- if (test_bit(MLX5E_CHANNEL_STATE_XSK, c->state))
+ if (test_bit(MLX5E_CHANNEL_STATE_XSK, c->state)) {
+ bpf_prog_inc(prog);
mlx5e_rq_replace_xdp_prog(&c->xskrq, prog);
+ }
}

unlock:
--
2.30.1