/*
* Routines to manage notifier chains for passing status changes to any
* interested routines. We need this instead of hard coded call lists so
* that modules can poke their nose into the innards. The network devices
* needed them so here they are for the rest of you.
*
* Alan Cox <Alan.Cox@linux.org>
*/
#ifndef _LINUX_NOTIFIER_H
#define _LINUX_NOTIFIER_H
#include <linux/errno.h>
struct notifier_block
{
int (*notifier_call)(struct notifier_block *self, unsigned long, void *);
struct notifier_block *next;
int priority;
};
#ifdef __KERNEL__
extern int notifier_chain_register(struct notifier_block **list, struct notifier_block *n);
extern int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n);
extern int notifier_call_chain(struct notifier_block **n, unsigned long val, void *v);
#define NOTIFY_DONE 0x0000 /* Don't care */
#define NOTIFY_OK 0x0001 /* Suits me */
#define NOTIFY_STOP_MASK 0x8000 /* Don't call further */
#define NOTIFY_BAD (NOTIFY_STOP_MASK|0x0002) /* Bad/Veto action */
/*
* Clean way to return from the notifier and stop further calls.
*/
#define NOTIFY_STOP (NOTIFY_OK|NOTIFY_STOP_MASK)
/*
* Declared notifiers so far. I can imagine quite a few more chains
* over time (eg laptop power reset chains, reboot chain (to clean
* device units up), device [un]mount chain, module load/unload chain,
* low memory chain, screenblank chain (for plug in modular screenblankers)
* VC switch chains (for loadable kernel svgalib VC switch helpers) etc...
*/
/* netdevice notifier chain */
#define NETDEV_UP 0x0001 /* For now you can't veto a device up/down */
#define NETDEV_DOWN 0x0002
#define NETDEV_REBOOT 0x0003 /* Tell a protocol stack a network interface
detected a hardware crash and restarted
- we can use this eg to kick tcp sessions
once done */
#define NETDEV_CHANGE 0x0004 /* Notify device state change */
#define NETDEV_REGISTER 0x0005
#define NETDEV_UNREGISTER 0x0006
#define NETDEV_CHANGEMTU 0x0007
#define NETDEV_CHANGEADDR 0x0008
#define NETDEV_GOING_DOWN 0x0009
#define NETDEV_CHANGENAME 0x000A
#define NETDEV_FEAT_CHANGE 0x000B
#define SYS_DOWN 0x0001 /* Notify of system down */
#define SYS_RESTART SYS_DOWN
#define SYS_HALT 0x0002 /* Notify of system halt */
#define SYS_POWER_OFF 0x0003 /* Notify of system power off */
#define NETLINK_URELEASE 0x0001 /* Unicast netlink socket released */
#define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
#define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
#define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
#define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
#define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
#define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
#endif /* __KERNEL__ */
#endif /* _LINUX_NOTIFIER_H */