From 4567dc10934292a3171f98d28817d58127b73b72 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 7 Oct 2014 13:30:23 -0700 Subject: [PATCH] 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: Eric Dumazet Signed-off-by: Daniel Borkmann Acked-by: Jeff Kirsher Signed-off-by: David S. Miller --- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 90 +++++++++++---------- 1 file changed, 46 insertions(+), 44 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 267992b3de8a..3195d82e4942 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -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 @@ -2195,8 +2236,12 @@ 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 */ - writel(i, tx_ring->tail); + 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 @@ dma_error: 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; out_drop: -- 2.20.1