diff options
Diffstat (limited to 'include/linux/notifier.h')
| -rw-r--r-- | include/linux/notifier.h | 197 |
1 files changed, 0 insertions, 197 deletions
diff --git a/include/linux/notifier.h b/include/linux/notifier.h deleted file mode 100644 index 29bd2e10..00000000 --- a/include/linux/notifier.h +++ /dev/null @@ -1,197 +0,0 @@ -/* - * 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> -#include <linux/mutex.h> -#include <linux/rwsem.h> -//#include <linux/srcu.h> - -/* - * Notifier chains are of four types: - * - * Atomic notifier chains: Chain callbacks run in interrupt/atomic - * context. Callouts are not allowed to block. - * Blocking notifier chains: Chain callbacks run in process context. - * Callouts are allowed to block. - * Raw notifier chains: There are no restrictions on callbacks, - * registration, or unregistration. All locking and protection - * must be provided by the caller. - * SRCU notifier chains: A variant of blocking notifier chains, with - * the same restrictions. - * - * atomic_notifier_chain_register() may be called from an atomic context, - * but blocking_notifier_chain_register() and srcu_notifier_chain_register() - * must be called from a process context. Ditto for the corresponding - * _unregister() routines. - * - * atomic_notifier_chain_unregister(), blocking_notifier_chain_unregister(), - * and srcu_notifier_chain_unregister() _must not_ be called from within - * the call chain. - * - * SRCU notifier chains are an alternative form of blocking notifier chains. - * They use SRCU (Sleepable Read-Copy Update) instead of rw-semaphores for - * protection of the chain links. This means there is _very_ low overhead - * in srcu_notifier_call_chain(): no cache bounces and no memory barriers. - * As compensation, srcu_notifier_chain_unregister() is rather expensive. - * SRCU notifier chains should be used when the chain will be called very - * often but notifier_blocks will seldom be removed. Also, SRCU notifier - * chains are slightly more difficult to use because they require special - * runtime initialization. - */ - -struct notifier_block; - -typedef int (*notifier_fn_t)(struct notifier_block *nb, - unsigned long action, void *data); - -struct notifier_block { - notifier_fn_t notifier_call; - struct notifier_block __rcu *next; - int priority; -}; - -struct atomic_notifier_head { - spinlock_t lock; - struct notifier_block __rcu *head; -}; - -struct blocking_notifier_head { - struct rw_semaphore rwsem; - struct notifier_block __rcu *head; -}; - -struct raw_notifier_head { - struct notifier_block __rcu *head; -}; - -#define ATOMIC_INIT_NOTIFIER_HEAD(name) do { \ - spin_lock_init(&(name)->lock); \ - (name)->head = NULL; \ - } while (0) -#define BLOCKING_INIT_NOTIFIER_HEAD(name) do { \ - init_rwsem(&(name)->rwsem); \ - (name)->head = NULL; \ - } while (0) -#define RAW_INIT_NOTIFIER_HEAD(name) do { \ - (name)->head = NULL; \ - } while (0) - -#define ATOMIC_NOTIFIER_INIT(name) { \ - .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ - .head = NULL } -#define BLOCKING_NOTIFIER_INIT(name) { \ - .rwsem = __RWSEM_INITIALIZER((name).rwsem), \ - .head = NULL } -#define RAW_NOTIFIER_INIT(name) { \ - .head = NULL } - -#define ATOMIC_NOTIFIER_HEAD(name) \ - struct atomic_notifier_head name = \ - ATOMIC_NOTIFIER_INIT(name) -#define BLOCKING_NOTIFIER_HEAD(name) \ - struct blocking_notifier_head name = \ - BLOCKING_NOTIFIER_INIT(name) -#define RAW_NOTIFIER_HEAD(name) \ - struct raw_notifier_head name = \ - RAW_NOTIFIER_INIT(name) - -#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) - -#ifdef __KERNEL__ - -extern int atomic_notifier_chain_register(struct atomic_notifier_head *nh, - struct notifier_block *nb); -extern int blocking_notifier_chain_register(struct blocking_notifier_head *nh, - struct notifier_block *nb); -extern int raw_notifier_chain_register(struct raw_notifier_head *nh, - struct notifier_block *nb); - -extern int blocking_notifier_chain_cond_register( - struct blocking_notifier_head *nh, - struct notifier_block *nb); - -extern int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, - struct notifier_block *nb); -extern int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh, - struct notifier_block *nb); -extern int raw_notifier_chain_unregister(struct raw_notifier_head *nh, - struct notifier_block *nb); - -extern int atomic_notifier_call_chain(struct atomic_notifier_head *nh, - unsigned long val, void *v); -extern int __atomic_notifier_call_chain(struct atomic_notifier_head *nh, - unsigned long val, void *v, int nr_to_call, int *nr_calls); -extern int blocking_notifier_call_chain(struct blocking_notifier_head *nh, - unsigned long val, void *v); -extern int __blocking_notifier_call_chain(struct blocking_notifier_head *nh, - unsigned long val, void *v, int nr_to_call, int *nr_calls); -extern int raw_notifier_call_chain(struct raw_notifier_head *nh, - unsigned long val, void *v); -extern int __raw_notifier_call_chain(struct raw_notifier_head *nh, - unsigned long val, void *v, int nr_to_call, int *nr_calls); - -/* Encapsulate (negative) errno value (in particular, NOTIFY_BAD <=> EPERM). */ -static inline int notifier_from_errno(int err) -{ - if (err) - return NOTIFY_STOP_MASK | (NOTIFY_OK - err); - - return NOTIFY_OK; -} - -/* Restore (negative) errno value from notify return value. */ -static inline int notifier_to_errno(int ret) -{ - ret &= ~NOTIFY_STOP_MASK; - return ret > NOTIFY_OK ? NOTIFY_OK - ret : 0; -} - -/* - * 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... - */ - -/* CPU notfiers are defined in include/linux/cpu.h. */ - -/* netdevice notifiers are defined in include/linux/netdevice.h */ - -/* reboot notifiers are defined in include/linux/reboot.h. */ - -/* Hibernation and suspend events are defined in include/linux/suspend.h. */ - -/* Virtual Terminal events are defined in include/linux/vt.h. */ - -#define NETLINK_URELEASE 0x0001 /* Unicast netlink socket released */ - -/* Console keyboard events. - * Note: KBD_KEYCODE is always sent before KBD_UNBOUND_KEYCODE, KBD_UNICODE and - * KBD_KEYSYM. */ -#define KBD_KEYCODE 0x0001 /* Keyboard keycode, called before any other */ -#define KBD_UNBOUND_KEYCODE 0x0002 /* Keyboard keycode which is not bound to any other */ -#define KBD_UNICODE 0x0003 /* Keyboard unicode */ -#define KBD_KEYSYM 0x0004 /* Keyboard keysym */ -#define KBD_POST_KEYSYM 0x0005 /* Called after keyboard keysym interpretation */ - -extern struct blocking_notifier_head reboot_notifier_list; - -#endif /* __KERNEL__ */ -#endif /* _LINUX_NOTIFIER_H */ |