summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorEric Dumazet <edumazet@google.com>2014-10-08 08:19:27 -0700
committerDavid S. Miller <davem@davemloft.net>2014-10-08 16:08:04 -0400
commit535114539bb2c081b6680cb5a34be17e7b45df37 (patch)
treef23c322826074ddd2eb0cbb84104210996746570
parent709c48b39ecf11a81f3820c13a828c330fd832b9 (diff)
downloadop-kernel-dev-535114539bb2c081b6680cb5a34be17e7b45df37.zip
op-kernel-dev-535114539bb2c081b6680cb5a34be17e7b45df37.tar.gz
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.c5
-rw-r--r--include/linux/netdevice.h29
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 8726a4a..34c1378 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 3a4315b..838407a 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)
{
OpenPOWER on IntegriCloud