ether_addr_equal_64bits() can easy be used in place of ether_addr_equal()
here.
Padding in the 'net_bridge_port' structure is already there because it is a
huge structure and the required fields are not at the end.
'oldaddr' is local to the function. So add the required padding
explicitly and simplify its definition.
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
This patch is more a POC for me.
I'm unsure that using ether_addr_equal_64bits() is really useful. The
speedup should be mostly un-noticeable.
To make sure that we have the required padding, we either need to waste
some space or rely on the fact that the address is embedded in a large
enough structure. (which is the case here)
So, it looks fragile to me and not future-proof.
Feed-back highly appreciated to see if such patches are welcome and if I
should spend some time on it.
---
net/bridge/br_private.h | 5 +++++
net/bridge/br_stp_if.c | 12 +++++++-----
2 files changed, 12 insertions(+), 5 deletions(-)
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 2661dda1a92b..2f78090574c9 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -363,6 +363,11 @@ struct net_bridge_port {
unsigned char config_pending;
port_id port_id;
port_id designated_port;
+ /*
+ * designated_root and designated_bridge must NOT be at the end of the
+ * structure because ether_addr_equal_64bits() requires 2 bytes of
+ * padding.
+ */
bridge_id designated_root;
bridge_id designated_bridge;
u32 path_cost;
diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index 75204d36d7f9..1bf0aaf29e5e 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -221,9 +221,11 @@ int br_stp_set_enabled(struct net_bridge *br, unsigned long val,
/* called under bridge lock */
void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
{
- /* should be aligned on 2 bytes for ether_addr_equal() */
- unsigned short oldaddr_aligned[ETH_ALEN >> 1];
- unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
+ /*
+ * should be aligned on 2 bytes and have 2 bytes of padding for
+ * ether_addr_equal_64bits()
+ */
+ unsigned char oldaddr[ETH_ALEN + 2] __aligned(2);
struct net_bridge_port *p;
int wasroot;
@@ -236,10 +238,10 @@ void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
eth_hw_addr_set(br->dev, addr);
list_for_each_entry(p, &br->port_list, list) {
- if (ether_addr_equal(p->designated_bridge.addr, oldaddr))
+ if (ether_addr_equal_64bits(p->designated_bridge.addr, oldaddr))
memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
- if (ether_addr_equal(p->designated_root.addr, oldaddr))
+ if (ether_addr_equal_64bits(p->designated_root.addr, oldaddr))
memcpy(p->designated_root.addr, addr, ETH_ALEN);
}
--
2.32.0
