3 * $Id: sysrq.h,v 1.3 1997/07/17 11:54:33 mj Exp $
5 * Linux Magic System Request Key Hacks
7 * (c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
9 * (c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
10 * overhauled to use key registration
11 * based upon discusions in irc://irc.openprojects.net/#kernelnewbies
13 #ifndef __LINUX_SYSRQ_H__
14 #define __LINUX_SYSRQ_H__
16 #include <linux/config.h>
23 void (*handler)(int, struct pt_regs *,
24 struct kbd_struct *, struct tty_struct *);
29 #ifdef CONFIG_MAGIC_SYSRQ
31 /* Generic SysRq interface -- you may call it from any device driver, supplying
32 * ASCII code of the key, pointer to registers and kbd/tty structs (if they
33 * are available -- else NULL's).
36 void handle_sysrq(int, struct pt_regs *,
37 struct kbd_struct *, struct tty_struct *);
41 * Nonlocking version of handle sysrq, used by sysrq handlers that need to
45 void __handle_sysrq_nolock(int, struct pt_regs *,
46 struct kbd_struct *, struct tty_struct *);
51 * Sysrq registration manipulation functions
54 void __sysrq_lock_table (void);
55 void __sysrq_unlock_table (void);
56 struct sysrq_key_op *__sysrq_get_key_op (int key);
57 void __sysrq_put_key_op (int key, struct sysrq_key_op *op_p);
60 __sysrq_swap_key_ops_nolock(int key, struct sysrq_key_op *insert_op_p,
61 struct sysrq_key_op *remove_op_p)
64 if (__sysrq_get_key_op(key) == remove_op_p) {
65 __sysrq_put_key_op(key, insert_op_p);
74 __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
75 struct sysrq_key_op *remove_op_p) {
78 retval = __sysrq_swap_key_ops_nolock(key, insert_op_p, remove_op_p);
79 __sysrq_unlock_table();
83 static inline int register_sysrq_key(int key, struct sysrq_key_op *op_p)
85 return __sysrq_swap_key_ops(key, op_p, NULL);
88 static inline int unregister_sysrq_key(int key, struct sysrq_key_op *op_p)
90 return __sysrq_swap_key_ops(key, NULL, op_p);
95 static inline int __reterr(void)
100 #define register_sysrq_key(ig,nore) __reterr()
101 #define unregister_sysrq_key(ig,nore) __reterr()
106 /* Deferred actions */
108 extern volatile int emergency_sync_scheduled;
111 #define EMERG_REMOUNT 2
113 void do_emergency_sync(void);
115 #ifdef CONFIG_MAGIC_SYSRQ
116 #define CHECK_EMERGENCY_SYNC \
117 if (emergency_sync_scheduled) \
120 #define CHECK_EMERGENCY_SYNC
123 #endif /* __LINUX_SYSRQ_H__ */