Subject: [net 05/18] net/mlx5e: When changing XDP program without reset, take refs for XSK RQs

From: Saeed Mahameed <[email-masked]>
Date: Wed, 10 Mar 2021 11:03:29 -0800

From: Maxim Mikityanskiy <[email-masked]>

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 <[email-masked]>
Reviewed-by: Tariq Toukan <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 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 66d23cd275c1..6b761fb8d269 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -4695,8 +4695,10 @@ 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:
-- 
2.29.2