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/* -*- linux-c -*-
*
* $Id: sysrq.h,v 1.3 1997/07/17 11:54:33 mj Exp $
*
* Linux Magic System Request Key Hacks
*
* (c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
*
* (c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
* overhauled to use key registration
* based upon discusions in irc://irc.openprojects.net/#kernelnewbies
*/
#ifndef __LINUX_SYSRQ_H__
#define __LINUX_SYSRQ_H__
#include <linux/config.h>
struct pt_regs;
struct kbd_struct;
struct tty_struct;
struct sysrq_key_op {
void (*handler)(int, struct pt_regs *,
struct kbd_struct *, struct tty_struct *);
char *help_msg;
char *action_msg;
};
#ifdef CONFIG_MAGIC_SYSRQ
/* Generic SysRq interface -- you may call it from any device driver, supplying
* ASCII code of the key, pointer to registers and kbd/tty structs (if they
* are available -- else NULL's).
*/
void handle_sysrq(int, struct pt_regs *,
struct kbd_struct *, struct tty_struct *);
/*
* Nonlocking version of handle sysrq, used by sysrq handlers that need to
* call sysrq handlers
*/
void __handle_sysrq_nolock(int, struct pt_regs *,
struct kbd_struct *, struct tty_struct *);
/*
* Sysrq registration manipulation functions
*/
void __sysrq_lock_table (void);
void __sysrq_unlock_table (void);
struct sysrq_key_op *__sysrq_get_key_op (int key);
void __sysrq_put_key_op (int key, struct sysrq_key_op *op_p);
extern __inline__ int
__sysrq_swap_key_ops_nolock(int key, struct sysrq_key_op *insert_op_p,
struct sysrq_key_op *remove_op_p)
{
int retval;
if (__sysrq_get_key_op(key) == remove_op_p) {
__sysrq_put_key_op(key, insert_op_p);
retval = 0;
} else {
retval = -1;
}
return retval;
}
extern __inline__ int
__sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
struct sysrq_key_op *remove_op_p) {
int retval;
__sysrq_lock_table();
retval = __sysrq_swap_key_ops_nolock(key, insert_op_p, remove_op_p);
__sysrq_unlock_table();
return retval;
}
static inline int register_sysrq_key(int key, struct sysrq_key_op *op_p)
{
return __sysrq_swap_key_ops(key, op_p, NULL);
}
static inline int unregister_sysrq_key(int key, struct sysrq_key_op *op_p)
{
return __sysrq_swap_key_ops(key, NULL, op_p);
}
#else
static inline int __reterr(void)
{
return -EINVAL;
}
#define register_sysrq_key(ig,nore) __reterr()
#define unregister_sysrq_key(ig,nore) __reterr()
#endif
/* Deferred actions */
extern volatile int emergency_sync_scheduled;
#define EMERG_SYNC 1
#define EMERG_REMOUNT 2
void do_emergency_sync(void);
#ifdef CONFIG_MAGIC_SYSRQ
#define CHECK_EMERGENCY_SYNC \
if (emergency_sync_scheduled) \
do_emergency_sync();
#else
#define CHECK_EMERGENCY_SYNC
#endif
#endif /* __LINUX_SYSRQ_H__ */
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