[PATCH net-next v3 1/5] net: dsa: comment hot path requirements

From: Vivien Didelot
Date: Thu Jun 01 2017 - 16:09:58 EST


The DSA layer uses inline helpers and copy of the tagging functions for
faster access in hot path. Add comments to detail that.

Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx>
---
include/net/dsa.h | 3 +++
net/dsa/dsa_priv.h | 1 +
2 files changed, 4 insertions(+)

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 7de1234ba136..18ca0a935c96 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -127,6 +127,8 @@ struct dsa_switch_tree {
* protocol to use.
*/
struct net_device *master_netdev;
+
+ /* Copy of tag_ops->rcv for faster access in hot path */
struct sk_buff * (*rcv)(struct sk_buff *skb,
struct net_device *dev,
struct packet_type *pt,
@@ -465,6 +467,7 @@ struct mii_bus *dsa_host_dev_to_mii_bus(struct device *dev);

struct net_device *dsa_dev_to_net_device(struct device *dev);

+/* Keep inline for faster access in hot path */
static inline bool dsa_uses_tagged_protocol(struct dsa_switch_tree *dst)
{
return dst->rcv != NULL;
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 7459d5735d8b..db2a7b9edfb8 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -73,6 +73,7 @@ struct dsa_device_ops {
};

struct dsa_slave_priv {
+ /* Copy of dp->ds->dst->tag_ops->xmit for faster access in hot path */
struct sk_buff * (*xmit)(struct sk_buff *skb,
struct net_device *dev);

--
2.13.0