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linux
1/*
2 * Routines to manage notifier chains for passing status changes to any
3 * interested routines. We need this instead of hard coded call lists so
4 * that modules can poke their nose into the innards. The network devices
5 * needed them so here they are for the rest of you.
6 *
7 * Alan Cox <Alan.Cox@linux.org>
8 */
9
10#ifndef _LINUX_NOTIFIER_H
11#define _LINUX_NOTIFIER_H
12#include <linux/errno.h>
13
14struct notifier_block
15{
16 int (*notifier_call)(struct notifier_block *self, unsigned long, void *);
17 struct notifier_block *next;
18 int priority;
19};
20
21
22#ifdef __KERNEL__
23
24extern int notifier_chain_register(struct notifier_block **list, struct notifier_block *n);
25extern int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n);
26extern int notifier_call_chain(struct notifier_block **n, unsigned long val, void *v);
27
28#define NOTIFY_DONE 0x0000 /* Don't care */
29#define NOTIFY_OK 0x0001 /* Suits me */
30#define NOTIFY_STOP_MASK 0x8000 /* Don't call further */
31#define NOTIFY_BAD (NOTIFY_STOP_MASK|0x0002) /* Bad/Veto action */
32/*
33 * Clean way to return from the notifier and stop further calls.
34 */
35#define NOTIFY_STOP (NOTIFY_OK|NOTIFY_STOP_MASK)
36
37/*
38 * Declared notifiers so far. I can imagine quite a few more chains
39 * over time (eg laptop power reset chains, reboot chain (to clean
40 * device units up), device [un]mount chain, module load/unload chain,
41 * low memory chain, screenblank chain (for plug in modular screenblankers)
42 * VC switch chains (for loadable kernel svgalib VC switch helpers) etc...
43 */
44
45/* netdevice notifier chain */
46#define NETDEV_UP 0x0001 /* For now you can't veto a device up/down */
47#define NETDEV_DOWN 0x0002
48#define NETDEV_REBOOT 0x0003 /* Tell a protocol stack a network interface
49 detected a hardware crash and restarted
50 - we can use this eg to kick tcp sessions
51 once done */
52#define NETDEV_CHANGE 0x0004 /* Notify device state change */
53#define NETDEV_REGISTER 0x0005
54#define NETDEV_UNREGISTER 0x0006
55#define NETDEV_CHANGEMTU 0x0007
56#define NETDEV_CHANGEADDR 0x0008
57#define NETDEV_GOING_DOWN 0x0009
58#define NETDEV_CHANGENAME 0x000A
59#define NETDEV_FEAT_CHANGE 0x000B
60
61#define SYS_DOWN 0x0001 /* Notify of system down */
62#define SYS_RESTART SYS_DOWN
63#define SYS_HALT 0x0002 /* Notify of system halt */
64#define SYS_POWER_OFF 0x0003 /* Notify of system power off */
65
66#define NETLINK_URELEASE 0x0001 /* Unicast netlink socket released */
67
68#define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
69#define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
70#define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
71#define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
72#define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
73#define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
74
75#endif /* __KERNEL__ */
76#endif /* _LINUX_NOTIFIER_H */