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linux/net/dsa/dsa_priv.h
Vladimir Oltean 4e51bf44a0 net: bridge: move the switchdev object replay helpers to "push" mode 
Starting with commit 4f2673b3a2b6 ("net: bridge: add helper to replay
port and host-joined mdb entries"), DSA has introduced some bridge
helpers that replay switchdev events (FDB/MDB/VLAN additions and
deletions) that can be lost by the switchdev drivers in a variety of
circumstances:

- an IP multicast group was host-joined on the bridge itself before any
  switchdev port joined the bridge, leading to the host MDB entries
  missing in the hardware database.
- during the bridge creation process, the MAC address of the bridge was
  added to the FDB as an entry pointing towards the bridge device
  itself, but with no switchdev ports being part of the bridge yet, this
  local FDB entry would remain unknown to the switchdev hardware
  database.
- a VLAN/FDB/MDB was added to a bridge port that is a LAG interface,
  before any switchdev port joined that LAG, leading to the hardware
  database missing those entries.
- a switchdev port left a LAG that is a bridge port, while the LAG
  remained part of the bridge, and all FDB/MDB/VLAN entries remained
  installed in the hardware database of the switchdev port.

Also, since commit 0d2cfbd41c4a ("net: bridge: ignore switchdev events
for LAG ports which didn't request replay"), DSA introduced a method,
based on a const void *ctx, to ensure that two switchdev ports under the
same LAG that is a bridge port do not see the same MDB/VLAN entry being
replayed twice by the bridge, once for every bridge port that joins the
LAG.

With so many ordering corner cases being possible, it seems unreasonable
to expect a switchdev driver writer to get it right from the first try.
Therefore, now that DSA has experimented with the bridge replay helpers
for a little bit, we can move the code to the bridge driver where it is
more readily available to all switchdev drivers.

To convert the switchdev object replay helpers from "pull mode" (where
the driver asks for them) to a "push mode" (where the bridge offers them
automatically), the biggest problem is that the bridge needs to be aware
when a switchdev port joins and leaves, even when the switchdev is only
indirectly a bridge port (for example when the bridge port is a LAG
upper of the switchdev).

Luckily, we already have a hook for that, in the form of the newly
introduced switchdev_bridge_port_offload() and
switchdev_bridge_port_unoffload() calls. These offer a natural place for
hooking the object addition and deletion replays.

Extend the above 2 functions with:
- pointers to the switchdev atomic notifier (for FDB replays) and the
  blocking notifier (for MDB and VLAN replays).
- the "const void *ctx" argument required for drivers to be able to
  disambiguate between which port is targeted, when multiple ports are
  lowers of the same LAG that is a bridge port. Most of the drivers pass
  NULL to this argument, except the ones that support LAG offload and have
  the proper context check already in place in the switchdev blocking
  notifier handler.

Also unexport the replay helpers, since nobody except the bridge calls
them directly now.

Note that:
(a) we abuse the terminology slightly, because FDB entries are not
    "switchdev objects", but we count them as objects nonetheless.
    With no direct way to prove it, I think they are not modeled as
    switchdev objects because those can only be installed by the bridge
    to the hardware (as opposed to FDB entries which can be propagated
    in the other direction too). This is merely an abuse of terms, FDB
    entries are replayed too, despite not being objects.
(b) the bridge does not attempt to sync port attributes to newly joined
    ports, just the countable stuff (the objects). The reason for this
    is simple: no universal and symmetric way to sync and unsync them is
    known. For example, VLAN filtering: what to do on unsync, disable or
    leave it enabled? Similarly, STP state, ageing timer, etc etc. What
    a switchdev port does when it becomes standalone again is not really
    up to the bridge's competence, and the driver should deal with it.
    On the other hand, replaying deletions of switchdev objects can be
    seen a matter of cleanup and therefore be treated by the bridge,
    hence this patch.

We make the replay helpers opt-in for drivers, because they might not
bring immediate benefits for them:

- nbp_vlan_init() is called _after_ netdev_master_upper_dev_link(),
  so br_vlan_replay() should not do anything for the new drivers on
  which we call it. The existing drivers where there was even a slight
  possibility for there to exist a VLAN on a bridge port before they
  join it are already guarded against this: mlxsw and prestera deny
  joining LAG interfaces that are members of a bridge.

- br_fdb_replay() should now notify of local FDB entries, but I patched
  all drivers except DSA to ignore these new entries in commit
  2c4eca3ef716 ("net: bridge: switchdev: include local flag in FDB
  notifications"). Driver authors can lift this restriction as they
  wish, and when they do, they can also opt into the FDB replay
  functionality.

- br_mdb_replay() should fix a real issue which is described in commit
  4f2673b3a2b6 ("net: bridge: add helper to replay port and host-joined
  mdb entries"). However most drivers do not offload the
  SWITCHDEV_OBJ_ID_HOST_MDB to see this issue: only cpsw and am65_cpsw
  offload this switchdev object, and I don't completely understand the
  way in which they offload this switchdev object anyway. So I'll leave
  it up to these drivers' respective maintainers to opt into
  br_mdb_replay().

So most of the drivers pass NULL notifier blocks for the replay helpers,
except:
- dpaa2-switch which was already acked/regression-tested with the
  helpers enabled (and there isn't much of a downside in having them)
- ocelot which already had replay logic in "pull" mode
- DSA which already had replay logic in "pull" mode

An important observation is that the drivers which don't currently
request bridge event replays don't even have the
switchdev_bridge_port_{offload,unoffload} calls placed in proper places
right now. This was done to avoid unnecessary rework for drivers which
might never even add support for this. For driver writers who wish to
add replay support, this can be used as a tentative placement guide:
https://patchwork.kernel.org/project/netdevbpf/patch/20210720134655.892334-11-vladimir.oltean@nxp.com/

Cc: Vadym Kochan <vkochan@marvell.com>
Cc: Taras Chornyi <tchornyi@marvell.com>
Cc: Ioana Ciornei <ioana.ciornei@nxp.com>
Cc: Lars Povlsen <lars.povlsen@microchip.com>
Cc: Steen Hegelund <Steen.Hegelund@microchip.com>
Cc: UNGLinuxDriver@microchip.com
Cc: Claudiu Manoil <claudiu.manoil@nxp.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:26:23 -07:00

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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* net/dsa/dsa_priv.h - Hardware switch handling
* Copyright (c) 2008-2009 Marvell Semiconductor
*/
#ifndef __DSA_PRIV_H
#define __DSA_PRIV_H
#include <linux/if_bridge.h>
#include <linux/phy.h>
#include <linux/netdevice.h>
#include <linux/netpoll.h>
#include <net/dsa.h>
#include <net/gro_cells.h>
enum {
DSA_NOTIFIER_AGEING_TIME,
DSA_NOTIFIER_BRIDGE_JOIN,
DSA_NOTIFIER_BRIDGE_LEAVE,
DSA_NOTIFIER_FDB_ADD,
DSA_NOTIFIER_FDB_DEL,
DSA_NOTIFIER_HOST_FDB_ADD,
DSA_NOTIFIER_HOST_FDB_DEL,
DSA_NOTIFIER_HSR_JOIN,
DSA_NOTIFIER_HSR_LEAVE,
DSA_NOTIFIER_LAG_CHANGE,
DSA_NOTIFIER_LAG_JOIN,
DSA_NOTIFIER_LAG_LEAVE,
DSA_NOTIFIER_MDB_ADD,
DSA_NOTIFIER_MDB_DEL,
DSA_NOTIFIER_HOST_MDB_ADD,
DSA_NOTIFIER_HOST_MDB_DEL,
DSA_NOTIFIER_VLAN_ADD,
DSA_NOTIFIER_VLAN_DEL,
DSA_NOTIFIER_MTU,
DSA_NOTIFIER_TAG_PROTO,
DSA_NOTIFIER_MRP_ADD,
DSA_NOTIFIER_MRP_DEL,
DSA_NOTIFIER_MRP_ADD_RING_ROLE,
DSA_NOTIFIER_MRP_DEL_RING_ROLE,
DSA_NOTIFIER_TAG_8021Q_VLAN_ADD,
DSA_NOTIFIER_TAG_8021Q_VLAN_DEL,
};
/* DSA_NOTIFIER_AGEING_TIME */
struct dsa_notifier_ageing_time_info {
unsigned int ageing_time;
};
/* DSA_NOTIFIER_BRIDGE_* */
struct dsa_notifier_bridge_info {
struct net_device *br;
int tree_index;
int sw_index;
int port;
};
/* DSA_NOTIFIER_FDB_* */
struct dsa_notifier_fdb_info {
int sw_index;
int port;
const unsigned char *addr;
u16 vid;
};
/* DSA_NOTIFIER_MDB_* */
struct dsa_notifier_mdb_info {
const struct switchdev_obj_port_mdb *mdb;
int sw_index;
int port;
};
/* DSA_NOTIFIER_LAG_* */
struct dsa_notifier_lag_info {
struct net_device *lag;
int sw_index;
int port;
struct netdev_lag_upper_info *info;
};
/* DSA_NOTIFIER_VLAN_* */
struct dsa_notifier_vlan_info {
const struct switchdev_obj_port_vlan *vlan;
int sw_index;
int port;
struct netlink_ext_ack *extack;
};
/* DSA_NOTIFIER_MTU */
struct dsa_notifier_mtu_info {
bool targeted_match;
int sw_index;
int port;
int mtu;
};
/* DSA_NOTIFIER_TAG_PROTO_* */
struct dsa_notifier_tag_proto_info {
const struct dsa_device_ops *tag_ops;
};
/* DSA_NOTIFIER_MRP_* */
struct dsa_notifier_mrp_info {
const struct switchdev_obj_mrp *mrp;
int sw_index;
int port;
};
/* DSA_NOTIFIER_MRP_* */
struct dsa_notifier_mrp_ring_role_info {
const struct switchdev_obj_ring_role_mrp *mrp;
int sw_index;
int port;
};
/* DSA_NOTIFIER_TAG_8021Q_VLAN_* */
struct dsa_notifier_tag_8021q_vlan_info {
int tree_index;
int sw_index;
int port;
u16 vid;
};
struct dsa_switchdev_event_work {
struct dsa_switch *ds;
int port;
struct net_device *dev;
struct work_struct work;
unsigned long event;
/* Specific for SWITCHDEV_FDB_ADD_TO_DEVICE and
* SWITCHDEV_FDB_DEL_TO_DEVICE
*/
unsigned char addr[ETH_ALEN];
u16 vid;
bool host_addr;
};
/* DSA_NOTIFIER_HSR_* */
struct dsa_notifier_hsr_info {
struct net_device *hsr;
int sw_index;
int port;
};
struct dsa_slave_priv {
/* Copy of CPU port xmit for faster access in slave transmit hot path */
struct sk_buff * (*xmit)(struct sk_buff *skb,
struct net_device *dev);
struct gro_cells gcells;
/* DSA port data, such as switch, port index, etc. */
struct dsa_port *dp;
#ifdef CONFIG_NET_POLL_CONTROLLER
struct netpoll *netpoll;
#endif
/* TC context */
struct list_head mall_tc_list;
};
/* dsa.c */
const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol);
void dsa_tag_driver_put(const struct dsa_device_ops *ops);
const struct dsa_device_ops *dsa_find_tagger_by_name(const char *buf);
bool dsa_schedule_work(struct work_struct *work);
const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops);
static inline int dsa_tag_protocol_overhead(const struct dsa_device_ops *ops)
{
return ops->needed_headroom + ops->needed_tailroom;
}
/* master.c */
int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp);
void dsa_master_teardown(struct net_device *dev);
static inline struct net_device *dsa_master_find_slave(struct net_device *dev,
int device, int port)
{
struct dsa_port *cpu_dp = dev->dsa_ptr;
struct dsa_switch_tree *dst = cpu_dp->dst;
struct dsa_port *dp;
list_for_each_entry(dp, &dst->ports, list)
if (dp->ds->index == device && dp->index == port &&
dp->type == DSA_PORT_TYPE_USER)
return dp->slave;
return NULL;
}
/* port.c */
void dsa_port_set_tag_protocol(struct dsa_port *cpu_dp,
const struct dsa_device_ops *tag_ops);
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,
struct netlink_ext_ack *extack);
void dsa_port_pre_bridge_leave(struct dsa_port *dp, struct net_device *br);
void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br);
int dsa_port_lag_change(struct dsa_port *dp,
struct netdev_lag_lower_state_info *linfo);
int dsa_port_lag_join(struct dsa_port *dp, struct net_device *lag_dev,
struct netdev_lag_upper_info *uinfo,
struct netlink_ext_ack *extack);
void dsa_port_pre_lag_leave(struct dsa_port *dp, struct net_device *lag_dev);
void dsa_port_lag_leave(struct dsa_port *dp, struct net_device *lag_dev);
int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
struct netlink_ext_ack *extack);
bool dsa_port_skip_vlan_configuration(struct dsa_port *dp);
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 targeted_match);
int dsa_port_fdb_add(struct dsa_port *dp, const unsigned char *addr,
u16 vid);
int dsa_port_fdb_del(struct dsa_port *dp, const unsigned char *addr,
u16 vid);
int dsa_port_host_fdb_add(struct dsa_port *dp, const unsigned char *addr,
u16 vid);
int dsa_port_host_fdb_del(struct dsa_port *dp, const unsigned char *addr,
u16 vid);
int dsa_port_fdb_dump(struct dsa_port *dp, dsa_fdb_dump_cb_t *cb, void *data);
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_host_mdb_add(const struct dsa_port *dp,
const struct switchdev_obj_port_mdb *mdb);
int dsa_port_host_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,
struct switchdev_brport_flags flags,
struct netlink_ext_ack *extack);
int dsa_port_bridge_flags(const struct dsa_port *dp,
struct switchdev_brport_flags flags,
struct netlink_ext_ack *extack);
int dsa_port_mrouter(struct dsa_port *dp, bool mrouter,
struct netlink_ext_ack *extack);
int dsa_port_vlan_add(struct dsa_port *dp,
const struct switchdev_obj_port_vlan *vlan,
struct netlink_ext_ack *extack);
int dsa_port_vlan_del(struct dsa_port *dp,
const struct switchdev_obj_port_vlan *vlan);
int dsa_port_mrp_add(const struct dsa_port *dp,
const struct switchdev_obj_mrp *mrp);
int dsa_port_mrp_del(const struct dsa_port *dp,
const struct switchdev_obj_mrp *mrp);
int dsa_port_mrp_add_ring_role(const struct dsa_port *dp,
const struct switchdev_obj_ring_role_mrp *mrp);
int dsa_port_mrp_del_ring_role(const struct dsa_port *dp,
const struct switchdev_obj_ring_role_mrp *mrp);
int dsa_port_link_register_of(struct dsa_port *dp);
void dsa_port_link_unregister_of(struct dsa_port *dp);
int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr);
void dsa_port_hsr_leave(struct dsa_port *dp, struct net_device *hsr);
int dsa_port_tag_8021q_vlan_add(struct dsa_port *dp, u16 vid);
void dsa_port_tag_8021q_vlan_del(struct dsa_port *dp, u16 vid);
extern const struct phylink_mac_ops dsa_port_phylink_mac_ops;
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(struct dsa_port *dp,
const struct net_device *bridge_dev)
{
/* DSA ports connected to a bridge, and event was emitted
* for the bridge.
*/
return dp->bridge_dev == 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(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(dp, bridge_dev))
return true;
return false;
}
/* slave.c */
extern const struct dsa_device_ops notag_netdev_ops;
extern struct notifier_block dsa_slave_switchdev_notifier;
extern struct notifier_block dsa_slave_switchdev_blocking_notifier;
void dsa_slave_mii_bus_init(struct dsa_switch *ds);
int dsa_slave_create(struct dsa_port *dp);
void dsa_slave_destroy(struct net_device *slave_dev);
int dsa_slave_suspend(struct net_device *slave_dev);
int dsa_slave_resume(struct net_device *slave_dev);
int dsa_slave_register_notifier(void);
void dsa_slave_unregister_notifier(void);
void dsa_slave_setup_tagger(struct net_device *slave);
int dsa_slave_change_mtu(struct net_device *dev, int new_mtu);
static inline struct dsa_port *dsa_slave_to_port(const struct net_device *dev)
{
struct dsa_slave_priv *p = netdev_priv(dev);
return p->dp;
}
static inline struct net_device *
dsa_slave_to_master(const struct net_device *dev)
{
struct dsa_port *dp = dsa_slave_to_port(dev);
return dp->cpu_dp->master;
}
/* If under a bridge with vlan_filtering=0, make sure to send pvid-tagged
* frames as untagged, since the bridge will not untag them.
*/
static inline struct sk_buff *dsa_untag_bridge_pvid(struct sk_buff *skb)
{
struct dsa_port *dp = dsa_slave_to_port(skb->dev);
struct net_device *br = dp->bridge_dev;
struct net_device *dev = skb->dev;
struct net_device *upper_dev;
u16 vid, pvid, proto;
int err;
if (!br || br_vlan_enabled(br))
return skb;
err = br_vlan_get_proto(br, &proto);
if (err)
return skb;
/* Move VLAN tag from data to hwaccel */
if (!skb_vlan_tag_present(skb) && skb->protocol == htons(proto)) {
skb = skb_vlan_untag(skb);
if (!skb)
return NULL;
}
if (!skb_vlan_tag_present(skb))
return skb;
vid = skb_vlan_tag_get_id(skb);
/* We already run under an RCU read-side critical section since
* we are called from netif_receive_skb_list_internal().
*/
err = br_vlan_get_pvid_rcu(dev, &pvid);
if (err)
return skb;
if (vid != pvid)
return skb;
/* The sad part about attempting to untag from DSA is that we
* don't know, unless we check, if the skb will end up in
* the bridge's data path - br_allowed_ingress() - or not.
* For example, there might be an 8021q upper for the
* default_pvid of the bridge, which will steal VLAN-tagged traffic
* from the bridge's data path. This is a configuration that DSA
* supports because vlan_filtering is 0. In that case, we should
* definitely keep the tag, to make sure it keeps working.
*/
upper_dev = __vlan_find_dev_deep_rcu(br, htons(proto), vid);
if (upper_dev)
return skb;
__vlan_hwaccel_clear_tag(skb);
return skb;
}
/* switch.c */
int dsa_switch_register_notifier(struct dsa_switch *ds);
void dsa_switch_unregister_notifier(struct dsa_switch *ds);
/* dsa2.c */
void dsa_lag_map(struct dsa_switch_tree *dst, struct net_device *lag);
void dsa_lag_unmap(struct dsa_switch_tree *dst, struct net_device *lag);
int dsa_tree_notify(struct dsa_switch_tree *dst, unsigned long e, void *v);
int dsa_broadcast(unsigned long e, void *v);
int dsa_tree_change_tag_proto(struct dsa_switch_tree *dst,
struct net_device *master,
const struct dsa_device_ops *tag_ops,
const struct dsa_device_ops *old_tag_ops);
/* tag_8021q.c */
int dsa_tag_8021q_bridge_join(struct dsa_switch *ds,
struct dsa_notifier_bridge_info *info);
int dsa_tag_8021q_bridge_leave(struct dsa_switch *ds,
struct dsa_notifier_bridge_info *info);
int dsa_switch_tag_8021q_vlan_add(struct dsa_switch *ds,
struct dsa_notifier_tag_8021q_vlan_info *info);
int dsa_switch_tag_8021q_vlan_del(struct dsa_switch *ds,
struct dsa_notifier_tag_8021q_vlan_info *info);
extern struct list_head dsa_tree_list;
#endif
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