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: 29d40c9032 ("net/mlx4_en: Use prefetch in tx path")
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2014-10-08 08:19:27 -07:00
committed by David S. Miller
parent 709c48b39e
commit 535114539b
2 changed files with 32 additions and 2 deletions

View File

@@ -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)
{