1c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 2c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Routines to manage notifier chains for passing status changes to any 3c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * interested routines. We need this instead of hard coded call lists so 4c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * that modules can poke their nose into the innards. The network devices 5c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * needed them so here they are for the rest of you. 6c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 7c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Alan Cox <Alan.Cox@linux.org> 8c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 9c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 10c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#ifndef _LINUX_NOTIFIER_H 11c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define _LINUX_NOTIFIER_H 12c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#include <linux/errno.h> 13c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#include <linux/mutex.h> 14c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#include <linux/rwsem.h> 15c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 16c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 17c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Notifier chains are of three types: 18c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 19c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Atomic notifier chains: Chain callbacks run in interrupt/atomic 20c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * context. Callouts are not allowed to block. 21c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Blocking notifier chains: Chain callbacks run in process context. 22c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Callouts are allowed to block. 23c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Raw notifier chains: There are no restrictions on callbacks, 24c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * registration, or unregistration. All locking and protection 25c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * must be provided by the caller. 26c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 27c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * atomic_notifier_chain_register() may be called from an atomic context, 28c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * but blocking_notifier_chain_register() must be called from a process 29c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * context. Ditto for the corresponding _unregister() routines. 30c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 31c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * atomic_notifier_chain_unregister() and blocking_notifier_chain_unregister() 32c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * _must not_ be called from within the call chain. 33c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 34c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 35c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct notifier_block { 36c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru int (*notifier_call)(struct notifier_block *, unsigned long, void *); 37c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct notifier_block *next; 38c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru int priority; 39c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru}; 40c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 41c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct atomic_notifier_head { 42c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru spinlock_t lock; 43c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct notifier_block *head; 44c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru}; 45c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 46c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct blocking_notifier_head { 47c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct rw_semaphore rwsem; 48c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct notifier_block *head; 49c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru}; 50c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 51c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct raw_notifier_head { 52c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct notifier_block *head; 53c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru}; 54c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 55c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define ATOMIC_INIT_NOTIFIER_HEAD(name) do { \ 56c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru spin_lock_init(&(name)->lock); \ 57c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (name)->head = NULL; \ 58c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru } while (0) 59c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BLOCKING_INIT_NOTIFIER_HEAD(name) do { \ 60c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru init_rwsem(&(name)->rwsem); \ 61c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (name)->head = NULL; \ 62c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru } while (0) 63c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define RAW_INIT_NOTIFIER_HEAD(name) do { \ 64c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (name)->head = NULL; \ 65c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru } while (0) 66c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 67c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define ATOMIC_NOTIFIER_INIT(name) { \ 68c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ 69c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru .head = NULL } 70c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BLOCKING_NOTIFIER_INIT(name) { \ 71c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru .rwsem = __RWSEM_INITIALIZER((name).rwsem), \ 72c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru .head = NULL } 73c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define RAW_NOTIFIER_INIT(name) { \ 74c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru .head = NULL } 75c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 76c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define ATOMIC_NOTIFIER_HEAD(name) \ 77c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct atomic_notifier_head name = \ 78c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru ATOMIC_NOTIFIER_INIT(name) 79c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BLOCKING_NOTIFIER_HEAD(name) \ 80c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct blocking_notifier_head name = \ 81c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru BLOCKING_NOTIFIER_INIT(name) 82c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define RAW_NOTIFIER_HEAD(name) \ 83c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct raw_notifier_head name = \ 84c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru RAW_NOTIFIER_INIT(name) 85c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 86c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#ifdef __KERNEL__ 87c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 88c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int atomic_notifier_chain_register(struct atomic_notifier_head *, 89c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct notifier_block *); 90c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int blocking_notifier_chain_register(struct blocking_notifier_head *, 91c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct notifier_block *); 92c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int raw_notifier_chain_register(struct raw_notifier_head *, 93c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct notifier_block *); 94c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 95c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int atomic_notifier_chain_unregister(struct atomic_notifier_head *, 96c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct notifier_block *); 97c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int blocking_notifier_chain_unregister(struct blocking_notifier_head *, 98c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct notifier_block *); 99c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int raw_notifier_chain_unregister(struct raw_notifier_head *, 100c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct notifier_block *); 101c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 102c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int atomic_notifier_call_chain(struct atomic_notifier_head *, 103c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned long val, void *v); 104c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int blocking_notifier_call_chain(struct blocking_notifier_head *, 105c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned long val, void *v); 106c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int raw_notifier_call_chain(struct raw_notifier_head *, 107c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned long val, void *v); 108c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 109c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NOTIFY_DONE 0x0000 /* Don't care */ 110c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NOTIFY_OK 0x0001 /* Suits me */ 111c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NOTIFY_STOP_MASK 0x8000 /* Don't call further */ 112c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NOTIFY_BAD (NOTIFY_STOP_MASK|0x0002) 113c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru /* Bad/Veto action */ 114c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 115c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Clean way to return from the notifier and stop further calls. 116c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 117c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NOTIFY_STOP (NOTIFY_OK|NOTIFY_STOP_MASK) 118c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 119c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 120c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Declared notifiers so far. I can imagine quite a few more chains 121c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * over time (eg laptop power reset chains, reboot chain (to clean 122c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * device units up), device [un]mount chain, module load/unload chain, 123c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * low memory chain, screenblank chain (for plug in modular screenblankers) 124c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * VC switch chains (for loadable kernel svgalib VC switch helpers) etc... 125c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 126c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 127c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* netdevice notifier chain */ 128c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NETDEV_UP 0x0001 /* For now you can't veto a device up/down */ 129c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NETDEV_DOWN 0x0002 130c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NETDEV_REBOOT 0x0003 /* Tell a protocol stack a network interface 131c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru detected a hardware crash and restarted 132c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru - we can use this eg to kick tcp sessions 133c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru once done */ 134c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NETDEV_CHANGE 0x0004 /* Notify device state change */ 135c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NETDEV_REGISTER 0x0005 136c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NETDEV_UNREGISTER 0x0006 137c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NETDEV_CHANGEMTU 0x0007 138c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NETDEV_CHANGEADDR 0x0008 139c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NETDEV_GOING_DOWN 0x0009 140c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NETDEV_CHANGENAME 0x000A 141c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NETDEV_FEAT_CHANGE 0x000B 142c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 143c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define SYS_DOWN 0x0001 /* Notify of system down */ 144c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define SYS_RESTART SYS_DOWN 145c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define SYS_HALT 0x0002 /* Notify of system halt */ 146c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define SYS_POWER_OFF 0x0003 /* Notify of system power off */ 147c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 148c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define NETLINK_URELEASE 0x0001 /* Unicast netlink socket released */ 149c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 150c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */ 151c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */ 152c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */ 153c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */ 154c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */ 155c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */ 156c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 157c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif /* __KERNEL__ */ 158c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif /* _LINUX_NOTIFIER_H */ 159