xref: /linux-6.15/include/net/netdev_lock.h (revision e2f81e8f)
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 
9 static inline bool netdev_trylock(struct net_device *dev)
10 {
11 	return mutex_trylock(&dev->lock);
12 }
13 
14 static inline void netdev_assert_locked(const struct net_device *dev)
15 {
16 	lockdep_assert_held(&dev->lock);
17 }
18 
19 static inline void
20 netdev_assert_locked_or_invisible(const struct net_device *dev)
21 {
22 	if (dev->reg_state == NETREG_REGISTERED ||
23 	    dev->reg_state == NETREG_UNREGISTERING)
24 		netdev_assert_locked(dev);
25 }
26 
27 static inline bool netdev_need_ops_lock(const struct net_device *dev)
28 {
29 	bool ret = dev->request_ops_lock || !!dev->queue_mgmt_ops;
30 
31 #if IS_ENABLED(CONFIG_NET_SHAPER)
32 	ret |= !!dev->netdev_ops->net_shaper_ops;
33 #endif
34 
35 	return ret;
36 }
37 
38 static inline void netdev_lock_ops(struct net_device *dev)
39 {
40 	if (netdev_need_ops_lock(dev))
41 		netdev_lock(dev);
42 }
43 
44 static inline void netdev_unlock_ops(struct net_device *dev)
45 {
46 	if (netdev_need_ops_lock(dev))
47 		netdev_unlock(dev);
48 }
49 
50 static inline void netdev_ops_assert_locked(const struct net_device *dev)
51 {
52 	if (netdev_need_ops_lock(dev))
53 		lockdep_assert_held(&dev->lock);
54 }
55 
56 static inline int netdev_lock_cmp_fn(const struct lockdep_map *a,
57 				     const struct lockdep_map *b)
58 {
59 	/* Only lower devices currently grab the instance lock, so no
60 	 * real ordering issues can occur. In the near future, only
61 	 * hardware devices will grab instance lock which also does not
62 	 * involve any ordering. Suppress lockdep ordering warnings
63 	 * until (if) we start grabbing instance lock on pure SW
64 	 * devices (bond/team/veth/etc).
65 	 */
66 	if (a == b)
67 		return 0;
68 	return -1;
69 }
70 
71 #define netdev_lockdep_set_classes(dev)				\
72 {								\
73 	static struct lock_class_key qdisc_tx_busylock_key;	\
74 	static struct lock_class_key qdisc_xmit_lock_key;	\
75 	static struct lock_class_key dev_addr_list_lock_key;	\
76 	static struct lock_class_key dev_instance_lock_key;	\
77 	unsigned int i;						\
78 								\
79 	(dev)->qdisc_tx_busylock = &qdisc_tx_busylock_key;	\
80 	lockdep_set_class(&(dev)->addr_list_lock,		\
81 			  &dev_addr_list_lock_key);		\
82 	lockdep_set_class(&(dev)->lock,				\
83 			  &dev_instance_lock_key);		\
84 	lock_set_cmp_fn(&dev->lock, netdev_lock_cmp_fn, NULL);	\
85 	for (i = 0; i < (dev)->num_tx_queues; i++)		\
86 		lockdep_set_class(&(dev)->_tx[i]._xmit_lock,	\
87 				  &qdisc_xmit_lock_key);	\
88 }
89 
90 #endif
91