This is a note to let you know that I've just added the patch titled
net/mlx5e: Extend SKB room check to include PTP-SQ
to the 6.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-mlx5e-extend-skb-room-check-to-include-ptp-sq.patch
and it can be found in the queue-6.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7c4e7a0e593e987309e85a427588635c1abdee90
Author: Aya Levin <ayal@xxxxxxxxxx>
Date: Wed Oct 26 14:51:42 2022 +0100
net/mlx5e: Extend SKB room check to include PTP-SQ
[ Upstream commit 19b43a432e3e47db656a8269a74b50aef826950c ]
When tx_port_ts is set, the driver diverts all UPD traffic over PTP port
to a dedicated PTP-SQ. The SKBs are cached until the wire-CQE arrives.
When the packet size is greater then MTU, the firmware might drop it and
the packet won't be transmitted to the wire, hence the wire-CQE won't
reach the driver. In this case the SKBs are accumulated in the SKB fifo.
Add room check to consider the PTP-SQ SKB fifo, when the SKB fifo is
full, driver stops the queue resulting in a TX timeout. Devlink
TX-reporter can recover from it.
Fixes: 1880bc4e4a96 ("net/mlx5e: Add TX port timestamp support")
Signed-off-by: Aya Levin <ayal@xxxxxxxxxx>
Reviewed-by: Tariq Toukan <tariqt@xxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20221026135153.154807-5-saeed@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/ptp.h b/drivers/net/ethernet/mellanox/mlx5/core/en/ptp.h
index 92dbbec472ec..f324a0c6f869 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/ptp.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/ptp.h
@@ -6,6 +6,7 @@
#include "en.h"
#include "en_stats.h"
+#include "en/txrx.h"
#include <linux/ptp_classify.h>
#define MLX5E_PTP_CHANNEL_IX 0
@@ -68,6 +69,14 @@ static inline bool mlx5e_use_ptpsq(struct sk_buff *skb)
fk.ports.dst == htons(PTP_EV_PORT));
}
+static inline bool mlx5e_ptpsq_fifo_has_room(struct mlx5e_txqsq *sq)
+{
+ if (!sq->ptpsq)
+ return true;
+
+ return mlx5e_skb_fifo_has_room(&sq->ptpsq->skb_fifo);
+}
+
int mlx5e_ptp_open(struct mlx5e_priv *priv, struct mlx5e_params *params,
u8 lag_port, struct mlx5e_ptp **cp);
void mlx5e_ptp_close(struct mlx5e_ptp *c);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h b/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
index c208ea307bff..ff8ca7a7e103 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
@@ -57,6 +57,12 @@ netdev_tx_t mlx5e_xmit(struct sk_buff *skb, struct net_device *dev);
bool mlx5e_poll_tx_cq(struct mlx5e_cq *cq, int napi_budget);
void mlx5e_free_txqsq_descs(struct mlx5e_txqsq *sq);
+static inline bool
+mlx5e_skb_fifo_has_room(struct mlx5e_skb_fifo *fifo)
+{
+ return (*fifo->pc - *fifo->cc) < fifo->mask;
+}
+
static inline bool
mlx5e_wqc_has_room_for(struct mlx5_wq_cyc *wq, u16 cc, u16 pc, u16 n)
{
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
index 27f791feb517..4d45150a3f8e 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
@@ -391,6 +391,11 @@ mlx5e_txwqe_complete(struct mlx5e_txqsq *sq, struct sk_buff *skb,
if (unlikely(sq->ptpsq)) {
mlx5e_skb_cb_hwtstamp_init(skb);
mlx5e_skb_fifo_push(&sq->ptpsq->skb_fifo, skb);
+ if (!netif_tx_queue_stopped(sq->txq) &&
+ !mlx5e_skb_fifo_has_room(&sq->ptpsq->skb_fifo)) {
+ netif_tx_stop_queue(sq->txq);
+ sq->stats->stopped++;
+ }
skb_get(skb);
}
@@ -867,6 +872,7 @@ bool mlx5e_poll_tx_cq(struct mlx5e_cq *cq, int napi_budget)
if (netif_tx_queue_stopped(sq->txq) &&
mlx5e_wqc_has_room_for(&sq->wq, sq->cc, sq->pc, sq->stop_room) &&
+ mlx5e_ptpsq_fifo_has_room(sq) &&
!test_bit(MLX5E_SQ_STATE_RECOVERING, &sq->state)) {
netif_tx_wake_queue(sq->txq);
stats->wake++;
