summaryrefslogtreecommitdiff
path: root/include/linux/notifier.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/notifier.h')
-rw-r--r--include/linux/notifier.h75
1 files changed, 75 insertions, 0 deletions
diff --git a/include/linux/notifier.h b/include/linux/notifier.h
new file mode 100644
index 000000000000..9303a003e9ab
--- /dev/null
+++ b/include/linux/notifier.h
@@ -0,0 +1,75 @@
+/*
+ * 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 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 */