diff options
| author | Eric Dumazet <edumazet@google.com> | 2014-10-08 19:19:27 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-10-09 00:08:04 +0400 |
| commit | 535114539bb2c081b6680cb5a34be17e7b45df37 (patch) | |
| tree | f23c322826074ddd2eb0cbb84104210996746570 | |
| parent | 709c48b39ecf11a81f3820c13a828c330fd832b9 (diff) | |
| download | linux-535114539bb2c081b6680cb5a34be17e7b45df37.tar.xz | |
net: add netdev_txq_bql_{enqueue, complete}_prefetchw() helpers
Add two helpers so that drivers do not have to care of BQL being
available or not.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jim Davis <jim.epost@gmail.com>
Fixes: 29d40c903247 ("net/mlx4_en: Use prefetch in tx path")
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx4/en_tx.c | 5 | ||||
| -rw-r--r-- | include/linux/netdevice.h | 29 |
2 files changed, 32 insertions, 2 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c index 8726a4aee5a7..34c137878545 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c @@ -392,7 +392,8 @@ static bool mlx4_en_process_tx_cq(struct net_device *dev, if (!priv->port_up) return true; - prefetchw(&ring->tx_queue->dql.limit); + netdev_txq_bql_complete_prefetchw(ring->tx_queue); + index = cons_index & size_mask; cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor; last_nr_txbb = ACCESS_ONCE(ring->last_nr_txbb); @@ -737,7 +738,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) vlan_tag = vlan_tx_tag_get(skb); - prefetchw(&ring->tx_queue->dql); + netdev_txq_bql_enqueue_prefetchw(ring->tx_queue); /* Track current inflight packets for performance analysis */ AVG_PERF_COUNTER(priv->pstats.inflight_avg, diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 3a4315b39d20..838407aea705 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -30,6 +30,7 @@ #include <linux/bug.h> #include <linux/delay.h> #include <linux/atomic.h> +#include <linux/prefetch.h> #include <asm/cache.h> #include <asm/byteorder.h> @@ -2480,6 +2481,34 @@ netif_xmit_frozen_or_drv_stopped(const struct netdev_queue *dev_queue) return dev_queue->state & QUEUE_STATE_DRV_XOFF_OR_FROZEN; } +/** + * netdev_txq_bql_enqueue_prefetchw - prefetch bql data for write + * @dev_queue: pointer to transmit queue + * + * BQL enabled drivers might use this helper in their ndo_start_xmit(), + * to give appropriate hint to the cpu. + */ +static inline void netdev_txq_bql_enqueue_prefetchw(struct netdev_queue *dev_queue) +{ +#ifdef CONFIG_BQL + prefetchw(&dev_queue->dql.num_queued); +#endif +} + +/** + * netdev_txq_bql_complete_prefetchw - prefetch bql data for write + * @dev_queue: pointer to transmit queue + * + * BQL enabled drivers might use this helper in their TX completion path, + * to give appropriate hint to the cpu. + */ +static inline void netdev_txq_bql_complete_prefetchw(struct netdev_queue *dev_queue) +{ +#ifdef CONFIG_BQL + prefetchw(&dev_queue->dql.limit); +#endif +} + static inline void netdev_tx_sent_queue(struct netdev_queue *dev_queue, unsigned int bytes) { |