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>

2 files changed, 2 insertions, 7 deletions

diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index bab174c052b3..f07f547db53e 100644
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -1374,14 +1374,10 @@ void b53_phylink_mac_link_up(struct dsa_switch *ds, int port,
 }
 EXPORT_SYMBOL(b53_phylink_mac_link_up);
 
-int b53_vlan_filtering(struct dsa_switch *ds, int port, bool vlan_filtering,
-		       struct switchdev_trans *trans)
+int b53_vlan_filtering(struct dsa_switch *ds, int port, bool vlan_filtering)
 {
 	struct b53_device *dev = ds->priv;
 
-	if (switchdev_trans_ph_prepare(trans))
-		return 0;
-
 	b53_enable_vlan(dev, dev->vlan_enabled, vlan_filtering);
 
 	return 0;
diff --git a/drivers/net/dsa/b53/b53_priv.h b/drivers/net/dsa/b53/b53_priv.h
index 6d0c724763c7..9ab0fb409f78 100644
--- a/drivers/net/dsa/b53/b53_priv.h
+++ b/drivers/net/dsa/b53/b53_priv.h
@@ -348,8 +348,7 @@ void b53_phylink_mac_link_up(struct dsa_switch *ds, int port,
 			     struct phy_device *phydev,
 			     int speed, int duplex,
 			     bool tx_pause, bool rx_pause);
-int b53_vlan_filtering(struct dsa_switch *ds, int port, bool vlan_filtering,
-		       struct switchdev_trans *trans);
+int b53_vlan_filtering(struct dsa_switch *ds, int port, bool vlan_filtering);
 int b53_vlan_prepare(struct dsa_switch *ds, int port,
 		     const struct switchdev_obj_port_vlan *vlan);
 void b53_vlan_add(struct dsa_switch *ds, int port,