Subject: [net 4/9] net/mlx5e: RX, Fix flush and close release flow of regular rq for legacy rq

From: Saeed Mahameed <[email-masked]>
Date: Fri, 30 Jun 2023 11:15:39 -0700

From: Dragos Tatulea <[email-masked]>

Regular (non-XSK) RQs get flushed on XSK setup and re-activated on XSK
close. If the same regular RQ is closed (a config change for example)
soon after the XSK close, a double release occurs because the missing
wqes get released a second time.

Fixes: 3f93f82988bc ("net/mlx5e: RX, Defer page release in legacy rq for better recycling")
Signed-off-by: Dragos Tatulea <[email-masked]>
Reviewed-by: Tariq Toukan <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 704b022cd1f0..a9575219e455 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -390,10 +390,18 @@ static void mlx5e_dealloc_rx_wqe(struct mlx5e_rq *rq, u16 ix)
 {
 	struct mlx5e_wqe_frag_info *wi = get_frag(rq, ix);
 
-	if (rq->xsk_pool)
+	if (rq->xsk_pool) {
 		mlx5e_xsk_free_rx_wqe(wi);
-	else
+	} else {
 		mlx5e_free_rx_wqe(rq, wi);
+
+		/* Avoid a second release of the wqe pages: dealloc is called
+		 * for the same missing wqes on regular RQ flush and on regular
+		 * RQ close. This happens when XSK RQs come into play.
+		 */
+		for (int i = 0; i < rq->wqe.info.num_frags; i++, wi++)
+			wi->flags |= BIT(MLX5E_WQE_FRAG_SKIP_RELEASE);
+	}
 }
 
 static void mlx5e_xsk_free_rx_wqes(struct mlx5e_rq *rq, u16 ix, int wqe_bulk)
-- 
2.41.0