include/linux/sysrq.h

   1 /* -*- linux-c -*-
   2  *
   3  *      $Id: sysrq.h,v 1.3 1997/07/17 11:54:33 mj Exp $
   4  *
   5  *      Linux Magic System Request Key Hacks
   6  *
   7  *      (c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
   8  *
   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
  12  */
  13
  14 #ifndef _LINUX_SYSRQ_H
  15 #define _LINUX_SYSRQ_H
  16
  17 #include <linux/errno.h>
  18
  19 struct pt_regs;
  20 struct tty_struct;
  21
  22 /* Possible values of bitmask for enabling sysrq functions */
  23 /* 0x0001 is reserved for enable everything */
  24 #define SYSRQ_ENABLE_LOG        0x0002
  25 #define SYSRQ_ENABLE_KEYBOARD   0x0004
  26 #define SYSRQ_ENABLE_DUMP       0x0008
  27 #define SYSRQ_ENABLE_SYNC       0x0010
  28 #define SYSRQ_ENABLE_REMOUNT    0x0020
  29 #define SYSRQ_ENABLE_SIGNAL     0x0040
  30 #define SYSRQ_ENABLE_BOOT       0x0080
  31 #define SYSRQ_ENABLE_RTNICE     0x0100
  32
  33 struct sysrq_key_op {
  34         void (*handler)(int, struct tty_struct *);
  35         char *help_msg;
  36         char *action_msg;
  37         int enable_mask;
  38 };
  39
  40 #ifdef CONFIG_MAGIC_SYSRQ
  41
  42 extern int sysrq_on(void);
  43
  44 /*
  45  * Do not use this one directly:
  46  */
  47 extern int __sysrq_enabled;
  48
  49 /* Generic SysRq interface -- you may call it from any device driver, supplying
  50  * ASCII code of the key, pointer to registers and kbd/tty structs (if they
  51  * are available -- else NULL's).
  52  */
  53
  54 void handle_sysrq(int key, struct tty_struct *tty);
  55 void __handle_sysrq(int key, struct tty_struct *tty, int check_mask);
  56 int register_sysrq_key(int key, struct sysrq_key_op *op);
  57 int unregister_sysrq_key(int key, struct sysrq_key_op *op);
  58 struct sysrq_key_op *__sysrq_get_key_op(int key);
  59
  60 #else
  61
  62 static inline int sysrq_on(void)
  63 {
  64         return 0;
  65 }
  66 static inline int __reterr(void)
  67 {
  68         return -EINVAL;
  69 }
  70 static inline void handle_sysrq(int key, struct tty_struct *tty)
  71 {
  72 }
  73
  74 #define register_sysrq_key(ig,nore) __reterr()
  75 #define unregister_sysrq_key(ig,nore) __reterr()
  76
  77 #endif
  78
  79 #endif /* _LINUX_SYSRQ_H */