1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 
3 #ifndef _NET_NETDEV_LOCK_H
4 #define _NET_NETDEV_LOCK_H
5 
6 #include <linux/lockdep.h>
7 #include <linux/netdevice.h>
8 #include <linux/rtnetlink.h>
9 
netdev_trylock(struct net_device * dev)10 static inline bool netdev_trylock(struct net_device *dev)
11 {
12 	return mutex_trylock(&dev->lock);
13 }
14 
netdev_assert_locked(const struct net_device * dev)15 static inline void netdev_assert_locked(const struct net_device *dev)
16 {
17 	lockdep_assert_held(&dev->lock);
18 }
19 
20 static inline void
netdev_assert_locked_or_invisible(const struct net_device * dev)21 netdev_assert_locked_or_invisible(const struct net_device *dev)
22 {
23 	if (dev->reg_state == NETREG_REGISTERED ||
24 	    dev->reg_state == NETREG_UNREGISTERING)
25 		netdev_assert_locked(dev);
26 }
27 
netdev_need_ops_lock(const struct net_device * dev)28 static inline bool netdev_need_ops_lock(const struct net_device *dev)
29 {
30 	bool ret = dev->request_ops_lock || !!dev->queue_mgmt_ops;
31 
32 #if IS_ENABLED(CONFIG_NET_SHAPER)
33 	ret |= !!dev->netdev_ops->net_shaper_ops;
34 #endif
35 
36 	return ret;
37 }
38 
netdev_lock_ops(struct net_device * dev)39 static inline void netdev_lock_ops(struct net_device *dev)
40 {
41 	if (netdev_need_ops_lock(dev))
42 		netdev_lock(dev);
43 }
44 
netdev_unlock_ops(struct net_device * dev)45 static inline void netdev_unlock_ops(struct net_device *dev)
46 {
47 	if (netdev_need_ops_lock(dev))
48 		netdev_unlock(dev);
49 }
50 
netdev_ops_assert_locked(const struct net_device * dev)51 static inline void netdev_ops_assert_locked(const struct net_device *dev)
52 {
53 	if (netdev_need_ops_lock(dev))
54 		lockdep_assert_held(&dev->lock);
55 	else
56 		ASSERT_RTNL();
57 }
58 
59 static inline void
netdev_ops_assert_locked_or_invisible(const struct net_device * dev)60 netdev_ops_assert_locked_or_invisible(const struct net_device *dev)
61 {
62 	if (dev->reg_state == NETREG_REGISTERED ||
63 	    dev->reg_state == NETREG_UNREGISTERING)
64 		netdev_ops_assert_locked(dev);
65 }
66 
netdev_lock_cmp_fn(const struct lockdep_map * a,const struct lockdep_map * b)67 static inline int netdev_lock_cmp_fn(const struct lockdep_map *a,
68 				     const struct lockdep_map *b)
69 {
70 	/* Only lower devices currently grab the instance lock, so no
71 	 * real ordering issues can occur. In the near future, only
72 	 * hardware devices will grab instance lock which also does not
73 	 * involve any ordering. Suppress lockdep ordering warnings
74 	 * until (if) we start grabbing instance lock on pure SW
75 	 * devices (bond/team/veth/etc).
76 	 */
77 	if (a == b)
78 		return 0;
79 	return -1;
80 }
81 
82 #define netdev_lockdep_set_classes(dev)				\
83 {								\
84 	static struct lock_class_key qdisc_tx_busylock_key;	\
85 	static struct lock_class_key qdisc_xmit_lock_key;	\
86 	static struct lock_class_key dev_addr_list_lock_key;	\
87 	static struct lock_class_key dev_instance_lock_key;	\
88 	unsigned int i;						\
89 								\
90 	(dev)->qdisc_tx_busylock = &qdisc_tx_busylock_key;	\
91 	lockdep_set_class(&(dev)->addr_list_lock,		\
92 			  &dev_addr_list_lock_key);		\
93 	lockdep_set_class(&(dev)->lock,				\
94 			  &dev_instance_lock_key);		\
95 	lock_set_cmp_fn(&dev->lock, netdev_lock_cmp_fn, NULL);	\
96 	for (i = 0; i < (dev)->num_tx_queues; i++)		\
97 		lockdep_set_class(&(dev)->_tx[i]._xmit_lock,	\
98 				  &qdisc_xmit_lock_key);	\
99 }
100 
101 #define netdev_lock_dereference(p, dev)				\
102 	rcu_dereference_protected(p, lockdep_is_held(&(dev)->lock))
103 
104 int netdev_debug_event(struct notifier_block *nb, unsigned long event,
105 		       void *ptr);
106 
107 #endif
108