[PATCH v3 net-next 1/8] net: dsa: Add helper to resolve bridge port from DSA port

From: Tobias Waldekranz <tobias@waldekranz.com>
To: davem@davemloft.net, kuba@kernel.org
Cc: andrew@lunn.ch, vivien.didelot@gmail.com, f.fainelli@gmail.com,
	olteanv@gmail.com, netdev@vger.kernel.org
Subject: [PATCH v3 net-next 1/8] net: dsa: Add helper to resolve bridge port from DSA port
Date: Thu, 18 Mar 2021 20:25:33 +0100	[thread overview]
Message-ID: <20210318192540.895062-2-tobias@waldekranz.com> (raw)
In-Reply-To: <20210318192540.895062-1-tobias@waldekranz.com>

In order for a driver to be able to query a bridge for information
about itself, e.g. reading out port flags, it has to use a netdev that
is known to the bridge. In the simple case, that is just the netdev
representing the port, e.g. swp0 or swp1 in this example:

   br0
   / \
swp0 swp1

But in the case of an offloaded lag, this will be the bond or team
interface, e.g. bond0 in this example:

     br0
     /
  bond0
   / \
swp0 swp1

Add a helper that hides some of this complexity from the
drivers. Then, redefine dsa_port_offloads_bridge_port using the helper
to avoid double accounting of the set of possible offloaded uppers.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
 include/net/dsa.h  | 14 ++++++++++++++
 net/dsa/dsa_priv.h | 14 +-------------
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/include/net/dsa.h b/include/net/dsa.h
index dac303edd33d..57b2c49f72f4 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -493,6 +493,20 @@ static inline bool dsa_port_is_vlan_filtering(const struct dsa_port *dp)
 		return dp->vlan_filtering;
 }
 
+static inline
+struct net_device *dsa_port_to_bridge_port(const struct dsa_port *dp)
+{
+	if (!dp->bridge_dev)
+		return NULL;
+
+	if (dp->lag_dev)
+		return dp->lag_dev;
+	else if (dp->hsr_dev)
+		return dp->hsr_dev;
+
+	return dp->slave;
+}
+
 typedef int dsa_fdb_dump_cb_t(const unsigned char *addr, u16 vid,
 			      bool is_static, void *data);
 struct dsa_switch_ops {
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 9d4b0e9b1aa1..4c43c5406834 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -233,19 +233,7 @@ extern const struct phylink_mac_ops dsa_port_phylink_mac_ops;
 static inline bool dsa_port_offloads_bridge_port(struct dsa_port *dp,
 						 struct net_device *dev)
 {
-	/* Switchdev offloading can be configured on: */
-
-	if (dev == dp->slave)
-		/* DSA ports directly connected to a bridge, and event
-		 * was emitted for the ports themselves.
-		 */
-		return true;
-
-	if (dp->lag_dev == dev)
-		/* DSA ports connected to a bridge via a LAG */
-		return true;
-
-	return false;
+	return dsa_port_to_bridge_port(dp) == dev;
 }
 
 static inline bool dsa_port_offloads_bridge(struct dsa_port *dp,
-- 
2.25.1

