[PATCH net-next V2 1/3] net: Introduce netif_xmit_timeout_ms() helper

[Tariq Toukan <tariqt@nvidia.com>]

From: Shahar Shitrit <shshitrit@nvidia.com>

Introduce a new helper function netif_xmit_timeout_ms() to check
if a TX queue is stopped and has timed out and report the timeout
duration. This makes the timeout logic reusable, and will be used
in several places in subsequent patches.

Signed-off-by: Shahar Shitrit <shshitrit@nvidia.com>
Reviewed-by: Yael Chemla <ychemla@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 include/net/netdev_queues.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/net/netdev_queues.h b/include/net/netdev_queues.h
index cd00e0406cf4..b55d3b9cb9c2 100644
--- a/include/net/netdev_queues.h
+++ b/include/net/netdev_queues.h
@@ -310,6 +310,17 @@ static inline void netif_subqueue_sent(const struct net_device *dev,
 	netdev_tx_sent_queue(txq, bytes);
 }
 
+static inline unsigned int netif_xmit_timeout_ms(struct netdev_queue *txq)
+{
+	unsigned long trans_start = READ_ONCE(txq->trans_start);
+
+	if (netif_xmit_stopped(txq) &&
+	    time_after(jiffies, trans_start + txq->dev->watchdog_timeo))
+		return jiffies_to_msecs(jiffies - trans_start);
+
+	return 0;
+}
+
 #define netif_subqueue_maybe_stop(dev, idx, get_desc, stop_thrs, start_thrs) \
 	({								\
 		struct netdev_queue *_txq;				\
-- 
2.31.1