Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e22979d9 authored by Yevgeny Petrilin's avatar Yevgeny Petrilin Committed by David S. Miller
Browse files

mlx4_en: Moving to Interrupts for TX completions 



Moving to interrupts instead of polling fpr TX completions
Avoiding situations where skb can be held in by the driver for
a long time (till timer expires).
The change is also necessary for supporting BQL.

Removing comp_lock that was required because we could handle TX
completions from several contexts: Interrupts, timer, polling.
Now there is only interrupts

Signed-off-by: default avatarYevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a19a848a

drivers/net/ethernet/mellanox/mlx4/en_cq.c

+3 −11
Original line number Diff line number Diff line
@@ -124,11 +124,7 @@ int mlx4_en_activate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq, 
	cq->mcq.comp  = cq->is_tx ? mlx4_en_tx_irq : mlx4_en_rx_irq;

	cq->mcq.event = mlx4_en_cq_event;



	if (cq->is_tx) {

		init_timer(&cq->timer);

		cq->timer.function = mlx4_en_poll_tx_cq;

		cq->timer.data = (unsigned long) cq;

	} else {

	if (!cq->is_tx) {

		netif_napi_add(cq->dev, &cq->napi, mlx4_en_poll_rx_cq, 64);

		napi_enable(&cq->napi);

	}
@@ -151,16 +147,12 @@ void mlx4_en_destroy_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq) 


void mlx4_en_deactivate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq)

{

	struct mlx4_en_dev *mdev = priv->mdev;



	if (cq->is_tx)

		del_timer(&cq->timer);

	else {

	if (!cq->is_tx) {

		napi_disable(&cq->napi);

		netif_napi_del(&cq->napi);

	}



	mlx4_cq_free(mdev->dev, &cq->mcq);

	mlx4_cq_free(priv->mdev->dev, &cq->mcq);

}



/* Set rx cq moderation parameters */

drivers/net/ethernet/mellanox/mlx4/en_netdev.c

+4 −0
Original line number Diff line number Diff line
@@ -667,6 +667,10 @@ int mlx4_en_start_port(struct net_device *dev) 
			mlx4_en_deactivate_cq(priv, cq);

			goto tx_err;

		}



		/* Arm CQ for TX completions */

		mlx4_en_arm_cq(priv, cq);



		/* Set initial ownership of all Tx TXBBs to SW (1) */

		for (j = 0; j < tx_ring->buf_size; j += STAMP_STRIDE)

			*((u32 *) (tx_ring->buf + j)) = 0xffffffff;

drivers/net/ethernet/mellanox/mlx4/en_tx.c

+1 −58
Original line number Diff line number Diff line
@@ -67,8 +67,6 @@ int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv, 


	inline_thold = min(inline_thold, MAX_INLINE);



	spin_lock_init(&ring->comp_lock);



	tmp = size * sizeof(struct mlx4_en_tx_info);

	ring->tx_info = vmalloc(tmp);

	if (!ring->tx_info)
@@ -377,40 +375,11 @@ void mlx4_en_tx_irq(struct mlx4_cq *mcq) 
{

	struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);

	struct mlx4_en_priv *priv = netdev_priv(cq->dev);

	struct mlx4_en_tx_ring *ring = &priv->tx_ring[cq->ring];



	if (!spin_trylock(&ring->comp_lock))

		return;

	mlx4_en_process_tx_cq(cq->dev, cq);

	mod_timer(&cq->timer, jiffies + 1);

	spin_unlock(&ring->comp_lock);

}





void mlx4_en_poll_tx_cq(unsigned long data)

{

	struct mlx4_en_cq *cq = (struct mlx4_en_cq *) data;

	struct mlx4_en_priv *priv = netdev_priv(cq->dev);

	struct mlx4_en_tx_ring *ring = &priv->tx_ring[cq->ring];

	u32 inflight;



	INC_PERF_COUNTER(priv->pstats.tx_poll);



	if (!spin_trylock_irq(&ring->comp_lock)) {

		mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT);

		return;

	mlx4_en_arm_cq(priv, cq);

}

	mlx4_en_process_tx_cq(cq->dev, cq);

	inflight = (u32) (ring->prod - ring->cons - ring->last_nr_txbb);



	/* If there are still packets in flight and the timer has not already

	 * been scheduled by the Tx routine then schedule it here to guarantee

	 * completion processing of these packets */

	if (inflight && priv->port_up)

		mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT);



	spin_unlock_irq(&ring->comp_lock);

}



static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv,

						      struct mlx4_en_tx_ring *ring,
@@ -440,25 +409,6 @@ static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv, 
	return ring->buf + index * TXBB_SIZE;

}



static inline void mlx4_en_xmit_poll(struct mlx4_en_priv *priv, int tx_ind)

{

	struct mlx4_en_cq *cq = &priv->tx_cq[tx_ind];

	struct mlx4_en_tx_ring *ring = &priv->tx_ring[tx_ind];

	unsigned long flags;



	/* If we don't have a pending timer, set one up to catch our recent

	   post in case the interface becomes idle */

	if (!timer_pending(&cq->timer))

		mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT);



	/* Poll the CQ every mlx4_en_TX_MODER_POLL packets */

	if ((++ring->poll_cnt & (MLX4_EN_TX_POLL_MODER - 1)) == 0)

		if (spin_trylock_irqsave(&ring->comp_lock, flags)) {

			mlx4_en_process_tx_cq(priv->dev, cq);

			spin_unlock_irqrestore(&ring->comp_lock, flags);

		}

}



static int is_inline(struct sk_buff *skb, void **pfrag)

{

	void *ptr;
@@ -590,7 +540,6 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 
	struct mlx4_en_priv *priv = netdev_priv(dev);

	struct mlx4_en_dev *mdev = priv->mdev;

	struct mlx4_en_tx_ring *ring;

	struct mlx4_en_cq *cq;

	struct mlx4_en_tx_desc *tx_desc;

	struct mlx4_wqe_data_seg *data;

	struct skb_frag_struct *frag;
@@ -638,9 +587,6 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 
		ring->blocked = 1;

		priv->port_stats.queue_stopped++;



		/* Use interrupts to find out when queue opened */

		cq = &priv->tx_cq[tx_ind];

		mlx4_en_arm_cq(priv, cq);

		return NETDEV_TX_BUSY;

	}
@@ -788,9 +734,6 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 
		iowrite32be(ring->doorbell_qpn, ring->bf.uar->map + MLX4_SEND_DOORBELL);

	}



	/* Poll CQ here */

	mlx4_en_xmit_poll(priv, tx_ind);



	return NETDEV_TX_OK;



tx_drop:

drivers/net/ethernet/mellanox/mlx4/mlx4_en.h

+1 −5
Original line number Diff line number Diff line
@@ -122,7 +122,7 @@ enum { 
#define MLX4_EN_RX_COAL_TARGET	44

#define MLX4_EN_RX_COAL_TIME	0x10



#define MLX4_EN_TX_COAL_PKTS	5

#define MLX4_EN_TX_COAL_PKTS	16

#define MLX4_EN_TX_COAL_TIME	0x80



#define MLX4_EN_RX_RATE_LOW		400000
@@ -255,7 +255,6 @@ struct mlx4_en_tx_ring { 
	unsigned long bytes;

	unsigned long packets;

	unsigned long tx_csum;

	spinlock_t comp_lock;

	struct mlx4_bf bf;

	bool bf_enabled;

};
@@ -308,8 +307,6 @@ struct mlx4_en_cq { 
	spinlock_t              lock;

	struct net_device      *dev;

	struct napi_struct	napi;

	/* Per-core Tx cq processing support */

	struct timer_list timer;

	int size;

	int buf_size;

	unsigned vector;
@@ -530,7 +527,6 @@ void mlx4_en_deactivate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq); 
int mlx4_en_set_cq_moder(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq);

int mlx4_en_arm_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq);



void mlx4_en_poll_tx_cq(unsigned long data);

void mlx4_en_tx_irq(struct mlx4_cq *mcq);

u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb);

netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev);