linux/net/switchdev/switchdev.c
Vladimir Oltean 69bfac968a net: switchdev: add a context void pointer to struct switchdev_notifier_info
In the case where the driver asks for a replay of a certain type of
event (port object or attribute) for a bridge port that is a LAG, it may
do so because this port has just joined the LAG.

But there might already be other switchdev ports in that LAG, and it is
preferable that those preexisting switchdev ports do not act upon the
replayed event.

The solution is to add a context to switchdev events, which is NULL most
of the time (when the bridge layer initiates the call) but which can be
set to a value controlled by the switchdev driver when a replay is
requested. The driver can then check the context to figure out if all
ports within the LAG should act upon the switchdev event, or just the
ones that match the context.

We have to modify all switchdev_handle_* helper functions as well as the
prototypes in the drivers that use these helpers too, because these
helpers hide the underlying struct switchdev_notifier_info from us and
there is no way to retrieve the context otherwise.

The context structure will be populated and used in later patches.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-28 14:09:03 -07:00

552 lines
15 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/switchdev/switchdev.c - Switch device API
* Copyright (c) 2014-2015 Jiri Pirko <jiri@resnulli.us>
* Copyright (c) 2014-2015 Scott Feldman <sfeldma@gmail.com>
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_bridge.h>
#include <linux/list.h>
#include <linux/workqueue.h>
#include <linux/if_vlan.h>
#include <linux/rtnetlink.h>
#include <net/switchdev.h>
static LIST_HEAD(deferred);
static DEFINE_SPINLOCK(deferred_lock);
typedef void switchdev_deferred_func_t(struct net_device *dev,
const void *data);
struct switchdev_deferred_item {
struct list_head list;
struct net_device *dev;
switchdev_deferred_func_t *func;
unsigned long data[];
};
static struct switchdev_deferred_item *switchdev_deferred_dequeue(void)
{
struct switchdev_deferred_item *dfitem;
spin_lock_bh(&deferred_lock);
if (list_empty(&deferred)) {
dfitem = NULL;
goto unlock;
}
dfitem = list_first_entry(&deferred,
struct switchdev_deferred_item, list);
list_del(&dfitem->list);
unlock:
spin_unlock_bh(&deferred_lock);
return dfitem;
}
/**
* switchdev_deferred_process - Process ops in deferred queue
*
* Called to flush the ops currently queued in deferred ops queue.
* rtnl_lock must be held.
*/
void switchdev_deferred_process(void)
{
struct switchdev_deferred_item *dfitem;
ASSERT_RTNL();
while ((dfitem = switchdev_deferred_dequeue())) {
dfitem->func(dfitem->dev, dfitem->data);
dev_put(dfitem->dev);
kfree(dfitem);
}
}
EXPORT_SYMBOL_GPL(switchdev_deferred_process);
static void switchdev_deferred_process_work(struct work_struct *work)
{
rtnl_lock();
switchdev_deferred_process();
rtnl_unlock();
}
static DECLARE_WORK(deferred_process_work, switchdev_deferred_process_work);
static int switchdev_deferred_enqueue(struct net_device *dev,
const void *data, size_t data_len,
switchdev_deferred_func_t *func)
{
struct switchdev_deferred_item *dfitem;
dfitem = kmalloc(sizeof(*dfitem) + data_len, GFP_ATOMIC);
if (!dfitem)
return -ENOMEM;
dfitem->dev = dev;
dfitem->func = func;
memcpy(dfitem->data, data, data_len);
dev_hold(dev);
spin_lock_bh(&deferred_lock);
list_add_tail(&dfitem->list, &deferred);
spin_unlock_bh(&deferred_lock);
schedule_work(&deferred_process_work);
return 0;
}
static int switchdev_port_attr_notify(enum switchdev_notifier_type nt,
struct net_device *dev,
const struct switchdev_attr *attr,
struct netlink_ext_ack *extack)
{
int err;
int rc;
struct switchdev_notifier_port_attr_info attr_info = {
.attr = attr,
.handled = false,
};
rc = call_switchdev_blocking_notifiers(nt, dev,
&attr_info.info, extack);
err = notifier_to_errno(rc);
if (err) {
WARN_ON(!attr_info.handled);
return err;
}
if (!attr_info.handled)
return -EOPNOTSUPP;
return 0;
}
static int switchdev_port_attr_set_now(struct net_device *dev,
const struct switchdev_attr *attr,
struct netlink_ext_ack *extack)
{
return switchdev_port_attr_notify(SWITCHDEV_PORT_ATTR_SET, dev, attr,
extack);
}
static void switchdev_port_attr_set_deferred(struct net_device *dev,
const void *data)
{
const struct switchdev_attr *attr = data;
int err;
err = switchdev_port_attr_set_now(dev, attr, NULL);
if (err && err != -EOPNOTSUPP)
netdev_err(dev, "failed (err=%d) to set attribute (id=%d)\n",
err, attr->id);
if (attr->complete)
attr->complete(dev, err, attr->complete_priv);
}
static int switchdev_port_attr_set_defer(struct net_device *dev,
const struct switchdev_attr *attr)
{
return switchdev_deferred_enqueue(dev, attr, sizeof(*attr),
switchdev_port_attr_set_deferred);
}
/**
* switchdev_port_attr_set - Set port attribute
*
* @dev: port device
* @attr: attribute to set
* @extack: netlink extended ack, for error message propagation
*
* rtnl_lock must be held and must not be in atomic section,
* in case SWITCHDEV_F_DEFER flag is not set.
*/
int switchdev_port_attr_set(struct net_device *dev,
const struct switchdev_attr *attr,
struct netlink_ext_ack *extack)
{
if (attr->flags & SWITCHDEV_F_DEFER)
return switchdev_port_attr_set_defer(dev, attr);
ASSERT_RTNL();
return switchdev_port_attr_set_now(dev, attr, extack);
}
EXPORT_SYMBOL_GPL(switchdev_port_attr_set);
static size_t switchdev_obj_size(const struct switchdev_obj *obj)
{
switch (obj->id) {
case SWITCHDEV_OBJ_ID_PORT_VLAN:
return sizeof(struct switchdev_obj_port_vlan);
case SWITCHDEV_OBJ_ID_PORT_MDB:
return sizeof(struct switchdev_obj_port_mdb);
case SWITCHDEV_OBJ_ID_HOST_MDB:
return sizeof(struct switchdev_obj_port_mdb);
default:
BUG();
}
return 0;
}
static int switchdev_port_obj_notify(enum switchdev_notifier_type nt,
struct net_device *dev,
const struct switchdev_obj *obj,
struct netlink_ext_ack *extack)
{
int rc;
int err;
struct switchdev_notifier_port_obj_info obj_info = {
.obj = obj,
.handled = false,
};
rc = call_switchdev_blocking_notifiers(nt, dev, &obj_info.info, extack);
err = notifier_to_errno(rc);
if (err) {
WARN_ON(!obj_info.handled);
return err;
}
if (!obj_info.handled)
return -EOPNOTSUPP;
return 0;
}
static void switchdev_port_obj_add_deferred(struct net_device *dev,
const void *data)
{
const struct switchdev_obj *obj = data;
int err;
ASSERT_RTNL();
err = switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
dev, obj, NULL);
if (err && err != -EOPNOTSUPP)
netdev_err(dev, "failed (err=%d) to add object (id=%d)\n",
err, obj->id);
if (obj->complete)
obj->complete(dev, err, obj->complete_priv);
}
static int switchdev_port_obj_add_defer(struct net_device *dev,
const struct switchdev_obj *obj)
{
return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
switchdev_port_obj_add_deferred);
}
/**
* switchdev_port_obj_add - Add port object
*
* @dev: port device
* @obj: object to add
* @extack: netlink extended ack
*
* rtnl_lock must be held and must not be in atomic section,
* in case SWITCHDEV_F_DEFER flag is not set.
*/
int switchdev_port_obj_add(struct net_device *dev,
const struct switchdev_obj *obj,
struct netlink_ext_ack *extack)
{
if (obj->flags & SWITCHDEV_F_DEFER)
return switchdev_port_obj_add_defer(dev, obj);
ASSERT_RTNL();
return switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
dev, obj, extack);
}
EXPORT_SYMBOL_GPL(switchdev_port_obj_add);
static int switchdev_port_obj_del_now(struct net_device *dev,
const struct switchdev_obj *obj)
{
return switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_DEL,
dev, obj, NULL);
}
static void switchdev_port_obj_del_deferred(struct net_device *dev,
const void *data)
{
const struct switchdev_obj *obj = data;
int err;
err = switchdev_port_obj_del_now(dev, obj);
if (err && err != -EOPNOTSUPP)
netdev_err(dev, "failed (err=%d) to del object (id=%d)\n",
err, obj->id);
if (obj->complete)
obj->complete(dev, err, obj->complete_priv);
}
static int switchdev_port_obj_del_defer(struct net_device *dev,
const struct switchdev_obj *obj)
{
return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
switchdev_port_obj_del_deferred);
}
/**
* switchdev_port_obj_del - Delete port object
*
* @dev: port device
* @obj: object to delete
*
* rtnl_lock must be held and must not be in atomic section,
* in case SWITCHDEV_F_DEFER flag is not set.
*/
int switchdev_port_obj_del(struct net_device *dev,
const struct switchdev_obj *obj)
{
if (obj->flags & SWITCHDEV_F_DEFER)
return switchdev_port_obj_del_defer(dev, obj);
ASSERT_RTNL();
return switchdev_port_obj_del_now(dev, obj);
}
EXPORT_SYMBOL_GPL(switchdev_port_obj_del);
static ATOMIC_NOTIFIER_HEAD(switchdev_notif_chain);
static BLOCKING_NOTIFIER_HEAD(switchdev_blocking_notif_chain);
/**
* register_switchdev_notifier - Register notifier
* @nb: notifier_block
*
* Register switch device notifier.
*/
int register_switchdev_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_register(&switchdev_notif_chain, nb);
}
EXPORT_SYMBOL_GPL(register_switchdev_notifier);
/**
* unregister_switchdev_notifier - Unregister notifier
* @nb: notifier_block
*
* Unregister switch device notifier.
*/
int unregister_switchdev_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&switchdev_notif_chain, nb);
}
EXPORT_SYMBOL_GPL(unregister_switchdev_notifier);
/**
* call_switchdev_notifiers - Call notifiers
* @val: value passed unmodified to notifier function
* @dev: port device
* @info: notifier information data
* @extack: netlink extended ack
* Call all network notifier blocks.
*/
int call_switchdev_notifiers(unsigned long val, struct net_device *dev,
struct switchdev_notifier_info *info,
struct netlink_ext_ack *extack)
{
info->dev = dev;
info->extack = extack;
return atomic_notifier_call_chain(&switchdev_notif_chain, val, info);
}
EXPORT_SYMBOL_GPL(call_switchdev_notifiers);
int register_switchdev_blocking_notifier(struct notifier_block *nb)
{
struct blocking_notifier_head *chain = &switchdev_blocking_notif_chain;
return blocking_notifier_chain_register(chain, nb);
}
EXPORT_SYMBOL_GPL(register_switchdev_blocking_notifier);
int unregister_switchdev_blocking_notifier(struct notifier_block *nb)
{
struct blocking_notifier_head *chain = &switchdev_blocking_notif_chain;
return blocking_notifier_chain_unregister(chain, nb);
}
EXPORT_SYMBOL_GPL(unregister_switchdev_blocking_notifier);
int call_switchdev_blocking_notifiers(unsigned long val, struct net_device *dev,
struct switchdev_notifier_info *info,
struct netlink_ext_ack *extack)
{
info->dev = dev;
info->extack = extack;
return blocking_notifier_call_chain(&switchdev_blocking_notif_chain,
val, info);
}
EXPORT_SYMBOL_GPL(call_switchdev_blocking_notifiers);
static int __switchdev_handle_port_obj_add(struct net_device *dev,
struct switchdev_notifier_port_obj_info *port_obj_info,
bool (*check_cb)(const struct net_device *dev),
int (*add_cb)(struct net_device *dev, const void *ctx,
const struct switchdev_obj *obj,
struct netlink_ext_ack *extack))
{
struct switchdev_notifier_info *info = &port_obj_info->info;
struct netlink_ext_ack *extack;
struct net_device *lower_dev;
struct list_head *iter;
int err = -EOPNOTSUPP;
extack = switchdev_notifier_info_to_extack(info);
if (check_cb(dev)) {
err = add_cb(dev, info->ctx, port_obj_info->obj, extack);
if (err != -EOPNOTSUPP)
port_obj_info->handled = true;
return err;
}
/* Switch ports might be stacked under e.g. a LAG. Ignore the
* unsupported devices, another driver might be able to handle them. But
* propagate to the callers any hard errors.
*
* If the driver does its own bookkeeping of stacked ports, it's not
* necessary to go through this helper.
*/
netdev_for_each_lower_dev(dev, lower_dev, iter) {
if (netif_is_bridge_master(lower_dev))
continue;
err = __switchdev_handle_port_obj_add(lower_dev, port_obj_info,
check_cb, add_cb);
if (err && err != -EOPNOTSUPP)
return err;
}
return err;
}
int switchdev_handle_port_obj_add(struct net_device *dev,
struct switchdev_notifier_port_obj_info *port_obj_info,
bool (*check_cb)(const struct net_device *dev),
int (*add_cb)(struct net_device *dev, const void *ctx,
const struct switchdev_obj *obj,
struct netlink_ext_ack *extack))
{
int err;
err = __switchdev_handle_port_obj_add(dev, port_obj_info, check_cb,
add_cb);
if (err == -EOPNOTSUPP)
err = 0;
return err;
}
EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_add);
static int __switchdev_handle_port_obj_del(struct net_device *dev,
struct switchdev_notifier_port_obj_info *port_obj_info,
bool (*check_cb)(const struct net_device *dev),
int (*del_cb)(struct net_device *dev, const void *ctx,
const struct switchdev_obj *obj))
{
struct switchdev_notifier_info *info = &port_obj_info->info;
struct net_device *lower_dev;
struct list_head *iter;
int err = -EOPNOTSUPP;
if (check_cb(dev)) {
err = del_cb(dev, info->ctx, port_obj_info->obj);
if (err != -EOPNOTSUPP)
port_obj_info->handled = true;
return err;
}
/* Switch ports might be stacked under e.g. a LAG. Ignore the
* unsupported devices, another driver might be able to handle them. But
* propagate to the callers any hard errors.
*
* If the driver does its own bookkeeping of stacked ports, it's not
* necessary to go through this helper.
*/
netdev_for_each_lower_dev(dev, lower_dev, iter) {
if (netif_is_bridge_master(lower_dev))
continue;
err = __switchdev_handle_port_obj_del(lower_dev, port_obj_info,
check_cb, del_cb);
if (err && err != -EOPNOTSUPP)
return err;
}
return err;
}
int switchdev_handle_port_obj_del(struct net_device *dev,
struct switchdev_notifier_port_obj_info *port_obj_info,
bool (*check_cb)(const struct net_device *dev),
int (*del_cb)(struct net_device *dev, const void *ctx,
const struct switchdev_obj *obj))
{
int err;
err = __switchdev_handle_port_obj_del(dev, port_obj_info, check_cb,
del_cb);
if (err == -EOPNOTSUPP)
err = 0;
return err;
}
EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_del);
static 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 void *ctx,
const struct switchdev_attr *attr,
struct netlink_ext_ack *extack))
{
struct switchdev_notifier_info *info = &port_attr_info->info;
struct netlink_ext_ack *extack;
struct net_device *lower_dev;
struct list_head *iter;
int err = -EOPNOTSUPP;
extack = switchdev_notifier_info_to_extack(info);
if (check_cb(dev)) {
err = set_cb(dev, info->ctx, port_attr_info->attr, extack);
if (err != -EOPNOTSUPP)
port_attr_info->handled = true;
return err;
}
/* Switch ports might be stacked under e.g. a LAG. Ignore the
* unsupported devices, another driver might be able to handle them. But
* propagate to the callers any hard errors.
*
* If the driver does its own bookkeeping of stacked ports, it's not
* necessary to go through this helper.
*/
netdev_for_each_lower_dev(dev, lower_dev, iter) {
if (netif_is_bridge_master(lower_dev))
continue;
err = __switchdev_handle_port_attr_set(lower_dev, port_attr_info,
check_cb, set_cb);
if (err && err != -EOPNOTSUPP)
return err;
}
return err;
}
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 void *ctx,
const struct switchdev_attr *attr,
struct netlink_ext_ack *extack))
{
int err;
err = __switchdev_handle_port_attr_set(dev, port_attr_info, check_cb,
set_cb);
if (err == -EOPNOTSUPP)
err = 0;
return err;
}
EXPORT_SYMBOL_GPL(switchdev_handle_port_attr_set);