Seal transmit path with regards to using destroyed mutex in mlx5en(4).

It may happen during link down that the running state may be observed
non-zero in the transmit routine, right before the running state is
cleared. This may end up using a destroyed mutex.

Make all channel mutexes and callouts persistant.

Preserve receive and send queue statistics during link toggle.

MFC after:	3 days
Sponsored by:	Mellanox Technologies

1 files changed, 15 insertions, 9 deletions

diff --git a/sys/dev/mlx5/mlx5_en/en.h b/sys/dev/mlx5/mlx5_en/en.h
index 192b19f24c2d..cf71559d5b86 100644
--- a/sys/dev/mlx5/mlx5_en/en.h
+++ b/sys/dev/mlx5/mlx5_en/en.h
@@ -139,6 +139,10 @@
 #define	MLX5E_100MB (100000)
 #define	MLX5E_1GB   (1000000)
 
+#define	MLX5E_ZERO(ptr, field)	      \
+	memset(&(ptr)->field, 0, \
+	    sizeof(*(ptr)) - __offsetof(__typeof(*(ptr)), field))
+
 MALLOC_DECLARE(M_MLX5EN);
 
 struct mlx5_core_dev;
@@ -741,15 +745,18 @@ struct mlx5e_rq_mbuf {
 };
 
 struct mlx5e_rq {
+	/* persistant fields */
+	struct mtx mtx;
+	struct mlx5e_rq_stats stats;
+
 	/* data path */
+#define	mlx5e_rq_zero_start wq
 	struct mlx5_wq_ll wq;
-	struct mtx mtx;
 	bus_dma_tag_t dma_tag;
 	u32	wqe_sz;
 	u32	nsegs;
 	struct mlx5e_rq_mbuf *mbuf;
 	struct ifnet *ifp;
-	struct mlx5e_rq_stats stats;
 	struct mlx5e_cq cq;
 	struct lro_ctrl lro;
 	volatile int enabled;
@@ -783,10 +790,14 @@ struct mlx5e_snd_tag {
 };
 
 struct mlx5e_sq {
-	/* data path */
+	/* persistant fields */
 	struct	mtx lock;
-	bus_dma_tag_t dma_tag;
 	struct	mtx comp_lock;
+	struct	mlx5e_sq_stats stats;
+
+	/* data path */
+#define	mlx5e_sq_zero_start dma_tag
+	bus_dma_tag_t dma_tag;
 
 	/* dirtied @completion */
 	u16	cc;
@@ -806,7 +817,6 @@ struct mlx5e_sq {
 		u32	d32[2];
 		u64	d64;
 	} doorbell;
-	struct	mlx5e_sq_stats stats;
 
 	struct	mlx5e_cq cq;
 
@@ -859,13 +869,9 @@ mlx5e_sq_queue_level(struct mlx5e_sq *sq)
 }
 
 struct mlx5e_channel {
-	/* data path */
 	struct mlx5e_rq rq;
 	struct mlx5e_snd_tag tag;
 	struct mlx5e_sq sq[MLX5E_MAX_TX_NUM_TC];
-	u8	num_tc;
-
-	/* control */
 	struct mlx5e_priv *priv;
 	int	ix;
 } __aligned(MLX5E_CACHELINE_SIZE);