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Commit 4567dc10 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

i40e: skb->xmit_more support 



Support skb->xmit_more in i40e is straightforward : we need to move
around i40e_maybe_stop_tx() call to correctly test netif_xmit_stopped()
before taking the decision to not kick the NIC.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.com>
Acked-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 44783d87

drivers/net/ethernet/intel/i40e/i40e_txrx.c

+46 −44
Original line number Diff line number Diff line
@@ -2052,6 +2052,47 @@ static void i40e_create_tx_ctx(struct i40e_ring *tx_ring, 
	context_desc->type_cmd_tso_mss = cpu_to_le64(cd_type_cmd_tso_mss);

}



/**

 * __i40e_maybe_stop_tx - 2nd level check for tx stop conditions

 * @tx_ring: the ring to be checked

 * @size:    the size buffer we want to assure is available

 *

 * Returns -EBUSY if a stop is needed, else 0

 **/

static inline int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)

{

	netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);

	/* Memory barrier before checking head and tail */

	smp_mb();



	/* Check again in a case another CPU has just made room available. */

	if (likely(I40E_DESC_UNUSED(tx_ring) < size))

		return -EBUSY;



	/* A reprieve! - use start_queue because it doesn't call schedule */

	netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index);

	++tx_ring->tx_stats.restart_queue;

	return 0;

}



/**

 * i40e_maybe_stop_tx - 1st level check for tx stop conditions

 * @tx_ring: the ring to be checked

 * @size:    the size buffer we want to assure is available

 *

 * Returns 0 if stop is not needed

 **/

#ifdef I40E_FCOE

int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)

#else

static int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)

#endif

{

	if (likely(I40E_DESC_UNUSED(tx_ring) >= size))

		return 0;

	return __i40e_maybe_stop_tx(tx_ring, size);

}



/**

 * i40e_tx_map - Build the Tx descriptor

 * @tx_ring:  ring to send buffer on
@@ -2195,7 +2236,11 @@ static void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb, 


	tx_ring->next_to_use = i;



	i40e_maybe_stop_tx(tx_ring, DESC_NEEDED);

	/* notify HW of packet */

	if (!skb->xmit_more ||

	    netif_xmit_stopped(netdev_get_tx_queue(tx_ring->netdev,

						   tx_ring->queue_index)))

		writel(i, tx_ring->tail);



	return;
@@ -2217,47 +2262,6 @@ static void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb, 
	tx_ring->next_to_use = i;

}



/**

 * __i40e_maybe_stop_tx - 2nd level check for tx stop conditions

 * @tx_ring: the ring to be checked

 * @size:    the size buffer we want to assure is available

 *

 * Returns -EBUSY if a stop is needed, else 0

 **/

static inline int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)

{

	netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);

	/* Memory barrier before checking head and tail */

	smp_mb();



	/* Check again in a case another CPU has just made room available. */

	if (likely(I40E_DESC_UNUSED(tx_ring) < size))

		return -EBUSY;



	/* A reprieve! - use start_queue because it doesn't call schedule */

	netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index);

	++tx_ring->tx_stats.restart_queue;

	return 0;

}



/**

 * i40e_maybe_stop_tx - 1st level check for tx stop conditions

 * @tx_ring: the ring to be checked

 * @size:    the size buffer we want to assure is available

 *

 * Returns 0 if stop is not needed

 **/

#ifdef I40E_FCOE

int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)

#else

static int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)

#endif

{

	if (likely(I40E_DESC_UNUSED(tx_ring) >= size))

		return 0;

	return __i40e_maybe_stop_tx(tx_ring, size);

}



/**

 * i40e_xmit_descriptor_count - calculate number of tx descriptors needed

 * @skb:     send buffer
@@ -2372,8 +2376,6 @@ static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb, 
	i40e_tx_map(tx_ring, skb, first, tx_flags, hdr_len,

		    td_cmd, td_offset);



	i40e_maybe_stop_tx(tx_ring, DESC_NEEDED);



	return NETDEV_TX_OK;



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