From: Dekel Peled <dekelp@nvidia.com>
Date: Thu, 15 Oct 2020 11:44:24 +0000 (+0300)
Subject: net/mlx5: fix use of atomic cmpset for age state
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=90e30c748801eaabb14c25c87550df01e9aaa6a9;p=dpdk.git

net/mlx5: fix use of atomic cmpset for age state

According to documentation [1], function rte_atomic16_cmpset()
return value is non-zero on success; 0 on failure.
In existing code this function is called, and the return value
is compared to AGE_CANDIDATE, which is defined as 1.
Such comparison is incorrect and can lead to unwanted behavior.

This patch updates the calls to rte_atomic16_cmpset(), to check
that the return value is 0 or non-zero.

[1] https://doc.dpdk.org/api/rte__atomic_8h.html

Fixes: fa2d01c87d2b ("net/mlx5: support flow aging")
Cc: stable@dpdk.org

Signed-off-by: Dekel Peled <dekelp@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>
---

diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
index a51a0a82bb..8faa83e7c1 100644
--- a/drivers/net/mlx5/mlx5_flow.c
+++ b/drivers/net/mlx5/mlx5_flow.c
@@ -6771,12 +6771,8 @@ mlx5_flow_aging_check(struct mlx5_dev_ctx_shared *sh,
 		priv = rte_eth_devices[age_param->port_id].data->dev_private;
 		age_info = GET_PORT_AGE_INFO(priv);
 		rte_spinlock_lock(&age_info->aged_sl);
-		/* If the cpmset fails, release happens. */
-		if (rte_atomic16_cmpset((volatile uint16_t *)
-					&age_param->state,
-					AGE_CANDIDATE,
-					AGE_TMOUT) ==
-					AGE_CANDIDATE) {
+		if (rte_atomic16_cmpset((volatile uint16_t *)&age_param->state,
+					AGE_CANDIDATE, AGE_TMOUT)) {
 			TAILQ_INSERT_TAIL(&age_info->aged_counters, cnt, next);
 			MLX5_AGE_SET(age_info, MLX5_AGE_EVENT_NEW);
 		}
diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
index 06c8b08260..b7ad84775d 100644
--- a/drivers/net/mlx5/mlx5_flow_dv.c
+++ b/drivers/net/mlx5/mlx5_flow_dv.c
@@ -5332,10 +5332,8 @@ flow_dv_counter_remove_from_age(struct rte_eth_dev *dev,
 
 	age_info = GET_PORT_AGE_INFO(priv);
 	age_param = flow_dv_counter_idx_get_age(dev, counter);
-	if (rte_atomic16_cmpset((volatile uint16_t *)
-			&age_param->state,
-			AGE_CANDIDATE, AGE_FREE)
-			!= AGE_CANDIDATE) {
+	if (!rte_atomic16_cmpset((volatile uint16_t *)&age_param->state,
+				 AGE_CANDIDATE, AGE_FREE)) {
 		/**
 		 * We need the lock even it is age timeout,
 		 * since counter may still in process.
@@ -5343,9 +5341,10 @@ flow_dv_counter_remove_from_age(struct rte_eth_dev *dev,
 		rte_spinlock_lock(&age_info->aged_sl);
 		TAILQ_REMOVE(&age_info->aged_counters, cnt, next);
 		rte_spinlock_unlock(&age_info->aged_sl);
+		rte_atomic16_set(&age_param->state, AGE_FREE);
 	}
-	rte_atomic16_set(&age_param->state, AGE_FREE);
 }
+
 /**
  * Release a flow counter.
  *