linux-stable/include/linux/dsa/8021q.h
Vladimir Oltean d3eed0e57d net: dsa: keep the bridge_dev and bridge_num as part of the same structure
The main desire behind this is to provide coherent bridge information to
the fast path without locking.

For example, right now we set dp->bridge_dev and dp->bridge_num from
separate code paths, it is theoretically possible for a packet
transmission to read these two port properties consecutively and find a
bridge number which does not correspond with the bridge device.

Another desire is to start passing more complex bridge information to
dsa_switch_ops functions. For example, with FDB isolation, it is
expected that drivers will need to be passed the bridge which requested
an FDB/MDB entry to be offloaded, and along with that bridge_dev, the
associated bridge_num should be passed too, in case the driver might
want to implement an isolation scheme based on that number.

We already pass the {bridge_dev, bridge_num} pair to the TX forwarding
offload switch API, however we'd like to remove that and squash it into
the basic bridge join/leave API. So that means we need to pass this
pair to the bridge join/leave API.

During dsa_port_bridge_leave, first we unset dp->bridge_dev, then we
call the driver's .port_bridge_leave with what used to be our
dp->bridge_dev, but provided as an argument.

When bridge_dev and bridge_num get folded into a single structure, we
need to preserve this behavior in dsa_port_bridge_leave: we need a copy
of what used to be in dp->bridge.

Switch drivers check bridge membership by comparing dp->bridge_dev with
the provided bridge_dev, but now, if we provide the struct dsa_bridge as
a pointer, they cannot keep comparing dp->bridge to the provided
pointer, since this only points to an on-stack copy. To make this
obvious and prevent driver writers from forgetting and doing stupid
things, in this new API, the struct dsa_bridge is provided as a full
structure (not very large, contains an int and a pointer) instead of a
pointer. An explicit comparison function needs to be used to determine
bridge membership: dsa_port_offloads_bridge().

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-08 14:31:16 -08:00

62 lines
1.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0
* Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com>
*/
#ifndef _NET_DSA_8021Q_H
#define _NET_DSA_8021Q_H
#include <linux/refcount.h>
#include <linux/types.h>
#include <net/dsa.h>
struct dsa_switch;
struct dsa_port;
struct sk_buff;
struct net_device;
struct dsa_tag_8021q_vlan {
struct list_head list;
int port;
u16 vid;
refcount_t refcount;
};
struct dsa_8021q_context {
struct dsa_switch *ds;
struct list_head vlans;
/* EtherType of RX VID, used for filtering on master interface */
__be16 proto;
};
int dsa_tag_8021q_register(struct dsa_switch *ds, __be16 proto);
void dsa_tag_8021q_unregister(struct dsa_switch *ds);
struct sk_buff *dsa_8021q_xmit(struct sk_buff *skb, struct net_device *netdev,
u16 tpid, u16 tci);
void dsa_8021q_rcv(struct sk_buff *skb, int *source_port, int *switch_id);
int dsa_tag_8021q_bridge_tx_fwd_offload(struct dsa_switch *ds, int port,
struct dsa_bridge bridge);
void dsa_tag_8021q_bridge_tx_fwd_unoffload(struct dsa_switch *ds, int port,
struct dsa_bridge bridge);
u16 dsa_8021q_bridge_tx_fwd_offload_vid(unsigned int bridge_num);
u16 dsa_tag_8021q_tx_vid(const struct dsa_port *dp);
u16 dsa_tag_8021q_rx_vid(const struct dsa_port *dp);
int dsa_8021q_rx_switch_id(u16 vid);
int dsa_8021q_rx_source_port(u16 vid);
bool vid_is_dsa_8021q_rxvlan(u16 vid);
bool vid_is_dsa_8021q_txvlan(u16 vid);
bool vid_is_dsa_8021q(u16 vid);
#endif /* _NET_DSA_8021Q_H */