regex/mlx5: fix overrun on enqueueing

When enqueueing a buffer the PMD check if there is room
in its send queue (SQ).
The current implementation did not take into account that
queue indices are wrapping around, which may result in
consumer index (sq->ci) can have bigger value than than
the producer index (sq->pi).

Fixes: 4d4e245ad637 ("regex/mlx5: support enqueue")
Signed-off-by: Yuval Avnery <yuvalav@mellanox.com>
Acked-by: Ori Kam <orika@mellanox.com>

diff --git a/drivers/regex/mlx5/mlx5_regex_fastpath.c b/drivers/regex/mlx5/mlx5_regex_fastpath.c
index d8af2bf96e2295131125d41d46917bf06b92a195..2c6c9e15a4977ab602ac55e342e9b1e371e11bf3 100644 (file)
--- a/drivers/regex/mlx5/mlx5_regex_fastpath.c
+++ b/drivers/regex/mlx5/mlx5_regex_fastpath.c
@@ -145,10 +145,7 @@ send_doorbell(struct mlx5dv_devx_uar *uar, struct mlx5_regex_sq *sq)
 
 static inline int
 can_send(struct mlx5_regex_sq *sq) {
-       return unlikely(sq->ci > sq->pi) ?
-                       MLX5_REGEX_MAX_WQE_INDEX + sq->pi - sq->ci <
-                       sq_size_get(sq) :
-                       sq->pi - sq->ci < sq_size_get(sq);
+       return ((uint16_t)(sq->pi - sq->ci) < sq_size_get(sq));
 }
 
 static inline uint32_t