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>

1 files changed, 6 insertions, 12 deletions

diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 9eaa85cc87ea..3e6063bf3f17 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -128,19 +128,16 @@ static inline struct net_device *dsa_master_find_slave(struct net_device *dev,
 }
 
 /* port.c */
-int dsa_port_set_state(struct dsa_port *dp, u8 state,
-		       struct switchdev_trans *trans);
+int dsa_port_set_state(struct dsa_port *dp, u8 state);
 int dsa_port_enable_rt(struct dsa_port *dp, struct phy_device *phy);
 int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy);
 void dsa_port_disable_rt(struct dsa_port *dp);
 void dsa_port_disable(struct dsa_port *dp);
 int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br);
 void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br);
-int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
-			    struct switchdev_trans *trans);
+int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering);
 bool dsa_port_skip_vlan_configuration(struct dsa_port *dp);
-int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock,
-			 struct switchdev_trans *trans);
+int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock);
 int dsa_port_mtu_change(struct dsa_port *dp, int new_mtu,
 			bool propagate_upstream);
 int dsa_port_fdb_add(struct dsa_port *dp, const unsigned char *addr,
@@ -152,12 +149,9 @@ int dsa_port_mdb_add(const struct dsa_port *dp,
 		     const struct switchdev_obj_port_mdb *mdb);
 int dsa_port_mdb_del(const struct dsa_port *dp,
 		     const struct switchdev_obj_port_mdb *mdb);
-int dsa_port_pre_bridge_flags(const struct dsa_port *dp, unsigned long flags,
-			      struct switchdev_trans *trans);
-int dsa_port_bridge_flags(const struct dsa_port *dp, unsigned long flags,
-			  struct switchdev_trans *trans);
-int dsa_port_mrouter(struct dsa_port *dp, bool mrouter,
-		     struct switchdev_trans *trans);
+int dsa_port_pre_bridge_flags(const struct dsa_port *dp, unsigned long flags);
+int dsa_port_bridge_flags(const struct dsa_port *dp, unsigned long flags);
+int dsa_port_mrouter(struct dsa_port *dp, bool mrouter);
 int dsa_port_vlan_add(struct dsa_port *dp,
 		      const struct switchdev_obj_port_vlan *vlan);
 int dsa_port_vlan_del(struct dsa_port *dp,