Merge branch 'rework-dsa-bridge-tx-forwarding-offload-api'

Vladimir Oltean says:

====================
Rework DSA bridge TX forwarding offload API

This change set is preparation work for DSA support of bridge FDB
isolation. It replaces struct net_device *dp->bridge_dev with a struct
dsa_bridge *dp->bridge that contains some extra information about that
bridge, like a unique number kept by DSA.

Up until now we computed that number only with the bridge TX forwarding
offload feature, but it will be needed for other features too, like for
isolation of FDB entries belonging to different bridges. Hardware
implementations vary, but one common pattern seems to be the presence of
a FID field which can be associated with that bridge number kept by DSA.
The idea was outlined here:
https://patchwork.kernel.org/project/netdevbpf/patch/20210818120150.892647-16-vladimir.oltean@nxp.com/
(the difference being that with this new proposal, drivers would not
need to call dsa_bridge_num_find, instead the bridge_num would be part
of the struct dsa_bridge :: num passed as argument).

No functional change is intended for drivers that don't already make use
of the bridge TX forwarding offload. I've tested the changes on the
felix, sja1105 and mv88e6xxx drivers, but nonetheless I'm copying all
DSA driver maintainers due to API changes that are taking place.

Compared to v1 and v2, the amount of patches is larger, but the contents
is mostly the same, just split up hopefully a bit better for review.
====================

Link: https://lore.kernel.org/r/20211206165758.1553882-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 88 insertions, 20 deletions

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 8ca9d50cbbc23..bdf308a5c55ee 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -219,6 +219,12 @@ struct dsa_mall_tc_entry {
 	};
 };
 
+struct dsa_bridge {
+	struct net_device *dev;
+	unsigned int num;
+	bool tx_fwd_offload;
+	refcount_t refcount;
+};
 
 struct dsa_port {
 	/* A CPU port is physically connected to a master device.
@@ -256,8 +262,7 @@ struct dsa_port {
 	/* Managed by DSA on user ports and by drivers on CPU and DSA ports */
 	bool			learning;
 	u8			stp_state;
-	struct net_device	*bridge_dev;
-	int			bridge_num;
+	struct dsa_bridge	*bridge;
 	struct devlink_port	devlink_port;
 	bool			devlink_port_setup;
 	struct phylink		*pl;
@@ -413,12 +418,12 @@ struct dsa_switch {
 	 */
 	unsigned int		num_lag_ids;
 
-	/* Drivers that support bridge forwarding offload should set this to
-	 * the maximum number of bridges spanning the same switch tree (or all
-	 * trees, in the case of cross-tree bridging support) that can be
-	 * offloaded.
+	/* Drivers that support bridge forwarding offload or FDB isolation
+	 * should set this to the maximum number of bridges spanning the same
+	 * switch tree (or all trees, in the case of cross-tree bridging
+	 * support) that can be offloaded.
 	 */
-	unsigned int		num_fwd_offloading_bridges;
+	unsigned int		max_num_bridges;
 
 	size_t num_ports;
 };
@@ -588,7 +593,7 @@ static inline bool dsa_port_is_vlan_filtering(const struct dsa_port *dp)
 static inline
 struct net_device *dsa_port_to_bridge_port(const struct dsa_port *dp)
 {
-	if (!dp->bridge_dev)
+	if (!dp->bridge)
 		return NULL;
 
 	if (dp->lag_dev)
@@ -599,6 +604,76 @@ struct net_device *dsa_port_to_bridge_port(const struct dsa_port *dp)
 	return dp->slave;
 }
 
+static inline struct net_device *
+dsa_port_bridge_dev_get(const struct dsa_port *dp)
+{
+	return dp->bridge ? dp->bridge->dev : NULL;
+}
+
+static inline unsigned int dsa_port_bridge_num_get(struct dsa_port *dp)
+{
+	return dp->bridge ? dp->bridge->num : 0;
+}
+
+static inline bool dsa_port_bridge_same(const struct dsa_port *a,
+					const struct dsa_port *b)
+{
+	struct net_device *br_a = dsa_port_bridge_dev_get(a);
+	struct net_device *br_b = dsa_port_bridge_dev_get(b);
+
+	/* Standalone ports are not in the same bridge with one another */
+	return (!br_a || !br_b) ? false : (br_a == br_b);
+}
+
+static inline bool dsa_port_offloads_bridge_port(struct dsa_port *dp,
+						 const struct net_device *dev)
+{
+	return dsa_port_to_bridge_port(dp) == dev;
+}
+
+static inline bool
+dsa_port_offloads_bridge_dev(struct dsa_port *dp,
+			     const struct net_device *bridge_dev)
+{
+	/* DSA ports connected to a bridge, and event was emitted
+	 * for the bridge.
+	 */
+	return dsa_port_bridge_dev_get(dp) == bridge_dev;
+}
+
+static inline bool dsa_port_offloads_bridge(struct dsa_port *dp,
+					    const struct dsa_bridge *bridge)
+{
+	return dsa_port_bridge_dev_get(dp) == bridge->dev;
+}
+
+/* Returns true if any port of this tree offloads the given net_device */
+static inline bool dsa_tree_offloads_bridge_port(struct dsa_switch_tree *dst,
+						 const struct net_device *dev)
+{
+	struct dsa_port *dp;
+
+	list_for_each_entry(dp, &dst->ports, list)
+		if (dsa_port_offloads_bridge_port(dp, dev))
+			return true;
+
+	return false;
+}
+
+/* Returns true if any port of this tree offloads the given bridge */
+static inline bool
+dsa_tree_offloads_bridge_dev(struct dsa_switch_tree *dst,
+			     const struct net_device *bridge_dev)
+{
+	struct dsa_port *dp;
+
+	list_for_each_entry(dp, &dst->ports, list)
+		if (dsa_port_offloads_bridge_dev(dp, bridge_dev))
+			return true;
+
+	return false;
+}
+
 typedef int dsa_fdb_dump_cb_t(const unsigned char *addr, u16 vid,
 			      bool is_static, void *data);
 struct dsa_switch_ops {
@@ -748,17 +823,10 @@ struct dsa_switch_ops {
 	 */
 	int	(*set_ageing_time)(struct dsa_switch *ds, unsigned int msecs);
 	int	(*port_bridge_join)(struct dsa_switch *ds, int port,
-				    struct net_device *bridge);
+				    struct dsa_bridge bridge,
+				    bool *tx_fwd_offload);
 	void	(*port_bridge_leave)(struct dsa_switch *ds, int port,
-				     struct net_device *bridge);
-	/* Called right after .port_bridge_join() */
-	int	(*port_bridge_tx_fwd_offload)(struct dsa_switch *ds, int port,
-					      struct net_device *bridge,
-					      int bridge_num);
-	/* Called right before .port_bridge_leave() */
-	void	(*port_bridge_tx_fwd_unoffload)(struct dsa_switch *ds, int port,
-						struct net_device *bridge,
-						int bridge_num);
+				     struct dsa_bridge bridge);
 	void	(*port_stp_state_set)(struct dsa_switch *ds, int port,
 				      u8 state);
 	void	(*port_fast_age)(struct dsa_switch *ds, int port);
@@ -830,10 +898,10 @@ struct dsa_switch_ops {
 	 */
 	int	(*crosschip_bridge_join)(struct dsa_switch *ds, int tree_index,
 					 int sw_index, int port,
-					 struct net_device *br);
+					 struct dsa_bridge bridge);
 	void	(*crosschip_bridge_leave)(struct dsa_switch *ds, int tree_index,
 					  int sw_index, int port,
-					  struct net_device *br);
+					  struct dsa_bridge bridge);
 	int	(*crosschip_lag_change)(struct dsa_switch *ds, int sw_index,
 					int port);
 	int	(*crosschip_lag_join)(struct dsa_switch *ds, int sw_index,