net: switchdev: remove the transaction structure from port attributes

Since the introduction of the switchdev API, port attributes were
transmitted to drivers for offloading using a two-step transactional
model, with a prepare phase that was supposed to catch all errors, and a
commit phase that was supposed to never fail.

Some classes of failures can never be avoided, like hardware access, or
memory allocation. In the latter case, merely attempting to move the
memory allocation to the preparation phase makes it impossible to avoid
memory leaks, since commit 91cf8eceffc1 ("switchdev: Remove unused
transaction item queue") which has removed the unused mechanism of
passing on the allocated memory between one phase and another.

It is time we admit that separating the preparation from the commit
phase is something that is best left for the driver to decide, and not
something that should be baked into the API, especially since there are
no switchdev callers that depend on this.

This patch removes the struct switchdev_trans member from switchdev port
attribute notifier structures, and converts drivers to not look at this
member.

In part, this patch contains a revert of my previous commit 2e554a7a5d8a
("net: dsa: propagate switchdev vlan_filtering prepare phase to
drivers").

For the most part, the conversion was trivial except for:
- Rocker's world implementation based on Broadcom OF-DPA had an odd
  implementation of ofdpa_port_attr_bridge_flags_set. The conversion was
  done mechanically, by pasting the implementation twice, then only
  keeping the code that would get executed during prepare phase on top,
  then only keeping the code that gets executed during the commit phase
  on bottom, then simplifying the resulting code until this was obtained.
- DSA's offloading of STP state, bridge flags, VLAN filtering and
  multicast router could be converted right away. But the ageing time
  could not, so a shim was introduced and this was left for a further
  commit.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de> # hellcreek
Reviewed-by: Linus Walleij <linus.walleij@linaro.org> # RTL8366RB
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 4 insertions, 9 deletions

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 9a0cab5fb7c4..d0f043091969 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -565,8 +565,7 @@ struct dsa_switch_ops {
 	 * VLAN support
 	 */
 	int	(*port_vlan_filtering)(struct dsa_switch *ds, int port,
-				       bool vlan_filtering,
-				       struct switchdev_trans *trans);
+				       bool vlan_filtering);
 	int (*port_vlan_prepare)(struct dsa_switch *ds, int port,
 				 const struct switchdev_obj_port_vlan *vlan);
 	void (*port_vlan_add)(struct dsa_switch *ds, int port,
diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index cbe6e35d51f5..f873e2c5e125 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h
@@ -239,7 +239,6 @@ struct switchdev_notifier_port_obj_info {
 struct switchdev_notifier_port_attr_info {
 	struct switchdev_notifier_info info; /* must be first */
 	const struct switchdev_attr *attr;
-	struct switchdev_trans *trans;
 	bool handled;
 };
 
@@ -298,8 +297,7 @@ int switchdev_handle_port_attr_set(struct net_device *dev,
 			struct switchdev_notifier_port_attr_info *port_attr_info,
 			bool (*check_cb)(const struct net_device *dev),
 			int (*set_cb)(struct net_device *dev,
-				      const struct switchdev_attr *attr,
-				      struct switchdev_trans *trans));
+				      const struct switchdev_attr *attr));
 #else
 
 static inline void switchdev_deferred_process(void)
@@ -390,8 +388,7 @@ switchdev_handle_port_attr_set(struct net_device *dev,
 			struct switchdev_notifier_port_attr_info *port_attr_info,
 			bool (*check_cb)(const struct net_device *dev),
 			int (*set_cb)(struct net_device *dev,
-				      const struct switchdev_attr *attr,
-				      struct switchdev_trans *trans))
+				      const struct switchdev_attr *attr))
 {
 	return 0;
 }
diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h
index 2f4cd3288bcc..f3db75c0172b 100644
--- a/include/soc/mscc/ocelot.h
+++ b/include/soc/mscc/ocelot.h
@@ -739,8 +739,7 @@ int ocelot_get_ts_info(struct ocelot *ocelot, int port,
 void ocelot_set_ageing_time(struct ocelot *ocelot, unsigned int msecs);
 void ocelot_adjust_link(struct ocelot *ocelot, int port,
 			struct phy_device *phydev);
-int ocelot_port_vlan_filtering(struct ocelot *ocelot, int port, bool enabled,
-			       struct switchdev_trans *trans);
+int ocelot_port_vlan_filtering(struct ocelot *ocelot, int port, bool enabled);
 void ocelot_bridge_stp_state_set(struct ocelot *ocelot, int port, u8 state);
 int ocelot_port_bridge_join(struct ocelot *ocelot, int port,
 			    struct net_device *bridge);