LXR linux-bk/include/linux/notifier.h

   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
  60#define SYS_DOWN        0x0001  /* Notify of system down */
  61#define SYS_RESTART     SYS_DOWN
  62#define SYS_HALT        0x0002  /* Notify of system halt */
  63#define SYS_POWER_OFF   0x0003  /* Notify of system power off */
  64
  65#define NETLINK_URELEASE        0x0001  /* Unicast netlink socket released */
  66
  67#define CPU_ONLINE      0x0002 /* CPU (unsigned)v is up */
  68#define CPU_UP_PREPARE  0x0003 /* CPU (unsigned)v coming up */
  69#define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
  70#define CPU_DEAD        0x0006 /* CPU (unsigned)v dead */
  71
  72#endif /* __KERNEL__ */
  73#endif /* _LINUX_NOTIFIER_H */
  74